旋转泵论文中英文对照资料外文翻译文献
循环球式转向器外文文献
Steering system profileAlong with automobile electronic technology swift and violent development, the people also day by day enhance to the motor turning handling quality request. The motor turning system changed, the hydraulic pressure boost from the traditional machinery changes (Hydraulic Power Steering, is called HPS), the electrically controlled hydraulic pressure boost changes (Elect ric Hydraulic Power Steering, is called EHPS), develops the electrically operated boost steering system (Elect ric Power Steering, is called EPS), finally also will transit to the line controls the steering system (Steer By Wire, will be called SBW).The machinery steering system is refers by pilot's physical strength achievement changes the energy, in which all power transmission all is mechanical, the automobile changes the movement is operates the steering wheel by the pilot, transmits through the diverter and a series of members changes the wheel to realize. The mechanical steering system by changes the control mechanism, the diverter and major part changes the gearing 3 to be composed.Usually may divide into according to the mechanical diverter form: The gear rack type, follows round the world -like, the worm bearing adjuster hoop type, the worm bearing adjuster refers sells the type. Is the gear rack type and follows using the broadest two kinds round the world -like (uses in needing time big steering force).In follows round the world -like in the diverter, the input changes the circle and the output steering arm pivot angle is proportional; In the gear rack type diverter, the input changes the turn and the output rack displacement is proportional. Follows round the world -like the diverter because is the rolling friction form, thus the transmission efficiency is very high, the ease of operation also the service life are long, moreover bearing capacity, therefore widely applies on the truck. The gear rack type diverter with follows round the world -like compares, the most major characteristic is the rigidity is big, the structure compact weight is light, also the cost is low. Because this way passes on easily by the wheel the reacting force to the steering wheel, therefore has to the pavement behavior response keen merit, but simultaneously also easy to have phenomena and so on goon and oscillation, also its load bearing efficiency relative weak, therefore mainly applies on the compact car and the pickup truck, at present the majority of low end passenger vehicle uses is the gear rack type machinery steering system.Along with the vehicles carrying capacity increase as well as the people to the vehicles handling quality request enhancement, the simple mechanical type steering system were already unable to meet the needs, the power steering system arise at the historic moment, it could rotate the steering wheel while the pilot to provide the boost, the power steering system divides into the hydraulic pressure steering system and the electrically operated steering system 2kinds.Hydraulic pressure steering system is at present uses the most widespread steering system.The hydraulic pressure steering system increased the hydraulic system in the mechanical system foundation, including hydraulic pump, V shape band pulley, drill tubing, feed installment, boost installment and control valve. It with the aid of in the motor car engine power actuation hydraulic pump, the air compressor and the generator and so on, by the fluid strength, the physical strength or the electric power increases the pilot to operate the strength which the front wheel changes, enables the pilot to be possible nimbly to operate motor turning facilely, reduced the labor intensity, enhanced the travel security.The hydraulic pressure boost steering system from invented already had about half century history to the present, might say was one kind of more perfect system, because its work reliable, the technology mature still widely is applied until now. It takes the power supply by the hydraulic pump, after oil pipe-line control valves to power hydraulic cylinder feed, through the connecting rod impetus rotation gear movement, may changes the boost through the change cylinder bore and the flowing tubing head pressure size the size, from this achieved changes the boost the function. The traditional hydraulic pressure type power steering system may divide into generally according to the liquid flow form: Ordinary flow type and atmospheric pressure type 2 kind of types, also may divide into according to the control valve form transfers the valve type and the slide-valve type.Along with hydraulic pressure power steering system on automobile daily popularization, the people to operates when the portability and the road feeling request also day by day enhance, however the hydraulic pressure power steering system has many shortcomings actually: ①Because its itself structure had decided it is unable to guarantee vehicles rotates the steering wheel when any operating mode, all has the ideal operation stability, namely is unable simultaneously to guarantee time the low speed changes the portability and the high speed time operation stability;②The automobile changes the characteristic to drive the pilot technical theinfluence to be serious; ③The steering ratio is fixed, causes the motor turning response characteristic along with changes and so on vehicle speed, transverse acceleration to change, the pilot must aim at the motor turning characteristic peak-to-peak value and the phase change ahead of time carries on certain operation compensation, thus controls the automobile according to its wish travel. Like this increased pilot's operation burden, also causes in the motor turning travel not to have the security hidden danger; But hereafter appeared the electrically controlled hydraulic booster system, it increases the velocity generator in the traditional hydraulic pressure power steering system foundation, enables the automobile along with the vehicle speed change automatic control force size, has to a certain extent relaxed the traditional hydraulic pressure steering system existence question.At present our country produces on the commercial vehicle and the passenger vehicle uses mostly is the electrically controlled hydraulic pressure boost steering system, it is quite mature and the application widespread steering system. Although the electrically controlled hydraulic servo alleviated the traditional hydraulic pressure from certain degree to change between the portability and the road feeling contradiction, however it did not have fundamentally to solve the HPS system existence insufficiency, along with automobile microelectronic technology development, automobile fuel oil energy conservation request as well as global initiative environmental protection, it in aspect and so on arrangement, installment, leak-proof quality, control sensitivity, energy consumption, attrition and noise insufficiencies already more and more obvious, the steering system turned towards the electrically operated boost steering system development.The electrically operated boost steering system is the present motor turning system development direction, its principle of work is: EPS system ECU after comes from the steering wheel torque sensor and the vehicle speed sensor signal carries on analysis processing, controls the electrical machinery to have the suitable boost torque, assists the pilot to complete changes the operation. In the last few years, along with the electronic technology development, reduces EPS the cost to become large scale possibly, Japan sends the car company, Mitsubishi Car company, this field car company, US's Delphi automobile system company, TRW Corporation and Germany's ZF Corporation greatly all one after another develops EPS.Mercedes2Benz 和Siemens Automotive Two big companies invested 65,000,000 pounds to use in developing EPS, the goal are together load a car to 2002, yearly produce 300 ten thousand sets, became the globalEPS manufacturer. So far, the EPS system in the slight passenger vehicle, on the theater box type vehicle obtains the widespread application, and every year by 300 ten thousand speed development.Steering is the term applied to the collection of components, linkages, etc. which allow for a vessel (ship, boat) or vehicle (car) to follow the desired course. An exception is the case of rail transport by which rail tracks combined together with railroad switches provide the steering function.The most conventional steering arrangement is to turn the front wheels using a hand–operated steering wheel which is positioned in front of the driver, via the steering column, which may contain universal joints to allow it to deviate somewhat from a straight line. Other arrangements are sometimes found on different types of vehicles, for example, a tiller or rear–wheel steering. Tracked vehicles such as tanks usually employ differential steering — that is, the tracks are made to move at different speeds or even in opposite directions to bring about a change of course.Many modern cars use rack and pinion steering mechanisms, where the steering wheel turns the pinion gear; the pinion moves the rack, which is a sort of linear gear which meshes with the pinion, from side to side. This motion applies steering torque to the kingpins of the steered wheels via tie rods and a short lever arm called the steering arm.Older designs often use the recirculating ball mechanism, which is still found on trucks and utility vehicles. This is a variation on the older worm and sector design; the steering column turns a large screw (the "worm gear") which meshes with a sector of a gear, causing it to rotate about its axis as the worm gear is turned; an arm attached to the axis of the sector moves the pitman arm, which is connected to the steering linkage and thus steers the wheels. The recirculating ball version of this apparatus reduces the considerable friction by placing large ball bearings between the teeth of the worm and those of the screw; at either end of the apparatus the balls exit from between the two pieces into a channel internal to the box which connects them with the other end of the apparatus, thus they are "recirculated".The rack and pinion design has the advantages of a large degree of feedback and direct steering "feel"; it also does not normally have any backlash, or slack. A disadvantage is that it is not adjustable, so that when it does wear and develop lash, the only cure is replacement.The recirculating ball mechanism has the advantage of a much greater mechanical advantage, so that it was found on larger, heavier vehicles while the rack and pinion was originally limited to smaller and lighter ones; due to the almost universal adoption of power steering, however, this is no longer an important advantage, leading to the increasing use of rack and pinion on newer cars. The recirculating ball design also has a perceptible lash, or "dead spot" on center, where a minute turn of the steering wheel in either direction does not move the steering apparatus; this is easily adjustable via a screw on the end of the steering box to account for wear, but it cannot be entirely eliminated or the mechanism begins to wear very rapidly. This design is still in use in trucks and other large vehicles, where rapidity of steering and direct feel are less important than robustness, maintainability, and mechanical advantage. The much smaller degree of feedback with this design can also sometimes be an advantage; drivers of vehicles with rack and pinion steering can have their thumbs broken when a front wheel hits a bump, causing the steering wheel to kick to one side suddenly (leading to driving instructors telling students to keep their thumbs on the front of the steering wheel, rather than wrapping around the inside of the rim). This effect is even stronger with a heavy vehicle like a truck; recirculating ball steering prevents this degree of feedback, just as it prevents desirable feedback under normal circumstances.The steering linkage connecting the steering box and the wheels usually conforms to a variation of Ackermann steering geometry, to account for the fact that in a turn, the inner wheel is actually traveling a path of smaller radius than the outer wheel, so that the degree of toe suitable for driving in a straight path is not suitable for turns.As vehicles have become heavier and switched to front wheel drive, the effort to turn the steering wheel manually has increased - often to the point where major physical exertion is required. To alleviate this, auto makers have developed power steering systems. There are two types of power steering systems—hydraulic and electric/electronic. There is also a hydraulic-electric hybrid system possible.A hydraulic power steering (HPS) uses hydraulic pressure supplied by an engine-driven pump to assist the motion of turning the steering wheel. Electric power steering (EPS) is more efficient than the hydraulic power steering, since the electric power steering motor only needs to provide assist when the steering wheel is turned, whereas the hydraulic pump must run constantly. In EPS the assist level is easily tunable to the vehicle type, road speed, and even driver preference.An added benefit is the elimination of environmental hazard posed by leakage and disposal of hydraulic power steering fluid.An outgrowth of power steering is speed adjustable steering, where the steering is heavily assisted at low speed and lightly assisted at high speed. The auto makers perceive that motorists might need to make large steering inputs while manoeuvering for parking, but not while traveling at high speed. The first vehicle with this feature was the Citroën SM with its Diravi layout, although rather than altering the amount of assistance as in modern power steering systems, it altered the pressure on a centring cam which made the steering wheel try to "spring" back to the straight-ahead position. Modern speed-adjustable power steering systems reduce the pressure fed to the ram as the speed increases, giving a more direct feel. This feature is gradually becoming commonplace across all new vehicles.Four-wheel steering (or all wheel steering) is a system employed by some vehicles to increase vehicle stability while maneuvering at high speed, or to decrease turning radius at low speed.In most four-wheel steering systems, the rear wheels are steered by a computer and actuators. The rear wheels generally cannot turn as far as the Alternatively, several systems, including Delphi's Quadrasteer and the system in Honda's Prelude line, allow for the rear wheels to be steered in the opposite direction as the front wheels during low speeds. This allows the vehicle to turn in a significantly smaller radius — sometimes critical for large trucks or vehicles with trailers.译文随着汽车电子技术的迅猛发展,人们对汽车转向操纵性能的要求也日益提高。
英文介绍水泵的作文
英文介绍水泵的作文英文：Water pumps are essential tools for moving water from one location to another. They are commonly used in homes, businesses, and industries for various purposes such as irrigation, drainage, and water supply.One of the most common types of water pumps is the centrifugal pump, which works by using a spinning impeller to create a flow of water. Another type is the positive displacement pump, which uses a mechanism to trap and move water through a series of chambers.Water pumps can also vary in size and power, depending on the amount of water that needs to be moved and the distance it needs to travel. For example, a small submersible pump may be used to drain a pool, while a large industrial pump may be used to supply water to an entire city.In addition, water pumps can be powered by various sources such as electricity, gasoline, or diesel. Some pumps even use solar power or wind power for a more sustainable and eco-friendly option.Overall, water pumps play a crucial role in our daily lives and are essential for ensuring the proper distribution and management of water resources.中文：水泵是将水从一个地方移动到另一个地方的必备工具。
水泵中英文对照
2一般术语2.1水力机械hydraulic machinery2.2 水轮机hydraulic turbine2.3 蓄能泵storage pump2.4 水泵水轮机reversible turbine，pump-turbine2.5 旋转方向direction of rotation2.6 机组unit2.13立式、卧式和倾斜式机组vertical，horizontal and inclined unit2.14可调式水力机械regulated hydraulic machinery2.15不可调式水力机械non-regulated hydraulic machinery2.16主阀main valve3.1水轮机3.1.1反击式水轮机reaction turbine3.1.2 混流式水轮机Francis turbine，mixed-flow turbine3.1.3 轴流式水轮机axial turbine3.1.4 轴流转桨式水轮机Kaplan turbine，axial-flow adjustable blad propeller turbine 3.1.5 轴流调桨式水轮机Thoma turbine3.1.6 轴流定桨式水轮机Propeller turbine3.1.7贯流式水轮机tubular turbine，through flow turbine3.1.8灯泡式水轮机bulb turbine3.1.9竖井贯流式水轮机pit turbine3.1.10全贯流式水轮机straight flow turbine，rim-generator unit3.1.11轴伸贯流式水轮机（S形水轮机）tubular turbine（S－type turbine）3.1.12 斜流式水轮机diagonal turbine3.1.13 斜流转桨式水轮机Deriaz turbine3.1.14斜流定桨式水轮机fixed blade of Deriaz turbine3.1.15冲击式水轮机impuls turbine，action turbine3.1.16水斗式水轮机Pelton turbine，scoop turbine3.1.17斜击式水轮机inclined jet turbine3.1.18双击式水轮机cross-flow turbine3.2蓄能泵3.2.1混流式（离心式）蓄能泵centrifugal storage pump，mixed-flow storage pump 3.2.2轴流式蓄能泵propeller storage pump，axial storage pump3.2.3斜流式蓄能泵diagonal storage pump3.2.4多级式蓄能泵multi-stage storage pump3.3水泵水轮机（又称可逆式水轮机）3.3.1单级水泵水轮机singal stage pump-turbine3.3.2多级水泵水轮机multi-stage pump-turbine3.4主阀与阀门3.4.1蝴蝶阀butterfly valve3.4.2 平板蝶阀biplane butterfly valve，through flow butterfly valve3.4.3 圆筒阀cylindrical valve，ring gate3.4.4 球阀rotary valve，spherical valve3.4.5 盘形阀mushroom valve，hollow-cone valve，howell-Bunger valve3.4.6 针形阀needle valve3.4.7 旁通阀by-pass valve3.4.8直空破坏阀vacuum break valve4结构部件4.1混流式水轮机4.1.1埋入部件embedded component4.1.2 引水室（turbine）flume4.1.3蜗壳spiral case4.1.4座环stay ring4.1.5 固定导叶stay vane4.1.6 蜗壳鼻端spiral case nose4.1.7基础环foundation ring，discharge ring4.1.8 尾水管draft tube4.1.9锥形尾水管conical draft tube4.1.10肘形尾水管elbow draft tube4.1.11尾水管锥管draft tube cone4.1.12尾水管肘管draft tube elbow4.1.13 尾水管扩散段draft tube outlet part4.1.14 尾水管支墩draft tube pier4.1.15 尾水管里衬draft tube liner4.1.16 机坑里衬pit liner4.1.17导水机构distributor4.1.18顶盖headcover，top cover4.1.19底环bottom ring，bottom cover4.1.20导叶guide vane，wicket gate4.1.21 控制环regulating ring，operating ring4.1.22 导叶臂guide vane lever，wicket gate lever4.1.23 分半键split key4.1.24 导叶连杆guide vanelink，wicket gate link4.1.25 导叶过载保护装置guide vane overload protection device 4.1.26 剪断销shear pin4.1.27 摩擦装置friction device4.1.28 导叶轴承guide vane bearing4.1.29 导叶止推轴承guide vane thrust bearing4.1.30 导叶轴密封guide vane stem seal4.1.31 导叶端面密封guide vane end seal4.1.32 导叶立面密封guide vane seal4.1.33抗磨板facing plates，wear plates4.1.34导叶限位块guide vane stop block4.1.35导叶接力器guide vane servomotor4.1.36 单导叶接力器individual guide vane servomotor4.1.37 推拉杆push and pull rod，connecting rod4.1.38 调速轴regulating shaft4.1.39 均压管balance pipe4.1.40 转动部件rotating component4.1.41 转轮runner4.1.42 叶片blade4.1.43 上冠crown4.1.44 下环band4.1.45 泄水锥runner cone4.1.46 转轮密封装置runner seal4.1.47 转轮止漏环runner wearing ring4.1.48 固定止漏环stationary wearing ring4.1.49 转轮减压板decompression plate4.1.50 主轴main shaft4.1.51 导轴承guide bearing4.1.52 轴领guide bearing collar4.1.53 轴瓦guide bearing shoe4.1.54 轴承体guide bearing housing4.1.55 主轴密封装置main shaft seal4.1.56 检修密封stand still seal4.1.57 联轴螺栓coupling bolt4.2 轴流式水轮机和斜流式水轮机。
中英文文献翻译-旋转泵
英文原文Rotary pumpThese are built in many different designs and are extremely popular in modern fluid-power system. The most common rotary-pump designs used today are spur-gear, generated-rotary , sliding-vane ,and screw pump ,each type has advantages that make it the most suitable for a given application .Spur-gear pumps. these pumps have two mating gears are turned in a closely fitted casing. Rotation of one gear ,the driver causes the second ,or follower gear, to turn . the driving shaft is usually connected to the upper gear of the pump .When the pump is first started ,rotation of gears forces air out the casing and into the discharge pipe. this removal of air from the pump casing produces a partial vacuum on the pump inlet ,here the fluid is trapped between the teeth of the upper and lower gears and the pump casing .continued rotation of the gears forces the fluid out of the pump discharge .Pressure rise in a spur-gear pump is produced by the squeezing action on the fluid ad it is expelled from between the meshing gear teeth and casing ,.a vacuum is formed in the cavity between the teeth ad unmesh, causing more fluid to be drawn into the pump ,a spur-gear pump is a constant-displacement unit ,its discharge is constant at a given shaft speed. the only way the quantity of fluid discharge by a spur-gear pump of type in figure can be regulated is by varying the shaft speed .modern gear pumps used in fluid-power systems develop pressures up to about 3000psi.Figure shows the typical characteristic curves of a spur-gear rotary pump. These curves show the capacity and power input for a spur-gear pump at various speeds. At any given speed the capacity characteristic is nearly a flat line the slight decrease in capacity with rise in discharge pressure is caused by increased leakage across the gears from the discharge to the suction side of the pump. leakage in gear pumps is sometimes termed slip. Slip also increase with arise pump discharge pressure .the curve showing the relation between pump discharge pressure and pump capacity is often termed the head-capacity or HQ curve .the relation between power input and pump capacity is the power-capacity or PQ curve .Power input to a squr-gear pump increases with both the operating speed and discharge pressure .as the speed of a gear pump is increased. Its discharge rate in gallons per minute also rise . thus the horsepower input at a discharge pressure of 120psi is 5hp at 200rpm and about 13hp at 600rpm.the corresponding capacities at these speed and pressure are 40 and 95gpm respectively, read on the 120psi ordinate where it crosses the 200-and 600-rpm HQ curves .Figure is based on spur-gear handing a fluid of constant viscosity , as the viscosity of the fluid handle increases (i.e. ,the fluid becomes thicker and has more resistance to flow ),the capacity of a gear pump decreases , thick ,viscous fluids may limit pump capacity t higher speeds because the fluid cannot into the casing rapidly enough fill it completely .figure shows the effect lf increasedfluid biscosity on the performance of rotary pump in fluid-power system .at 80-psi discharge pressure the pp has a capacity lf 220gpm when handling fluid of 100SSU viscosity lf 500SSU . the power input to the pump also rises ,as shown by the power characteristics.Capacity lf rotary pump is often expressed in gallons per revolution of the gear or other internal element .if the outlet of a positive-displacement rotary pump is completely closed, the discharge pressure will increase to the point where the pump driving motor stalls or some part of the pump casing or discharge pipe ruptures .because this danger of rupture exists systems are filled with a pressure –relief valve. This relief valve may be built as of the pump or it may be mounted in the discharge piping.Sliding-Vane PumpsThese pumps have a number of vanes which are free to slide into or out of slots in the pup rotor . when the rotor is turned by the pump driver , centrifugal force , springs , or pressurized fluid causes the vanes to move outward in their slots and bear against the inner bore of the pump casing or against a cam ring . as the rotor revolves , fluid flows in between the vanes when they pass the suction port. This fluid is carried around the pump casing until the discharge port is reached. Here the fluid is forced out of the casing and into the discharge pipe.In the sliding-vane pump in Figure the vanes in an oval-shaped bore. Centrifugal force starts the vanes out of their slots when the rotor begins turning. The vanes are held out by pressure which is bled into the cavities behind the vanes from a distributing ring at the end of the vane slots. Suction is through two ports A and AI, placed diametrically opposite each other. Two discharge ports are similarly placed. This arrangement of ports keeps the rotor in hydraulic balance, reliving the bearing of heavy loads. When the rotor turns counterclockwise, fluid from the suction pipe comes into ports A and AI is trapped between the vanes, and is carried around and discharged through ports B and BI. Pumps of this design are built for pressures up to 2500 psi. earlier models required staging to attain pressures approximating those currently available in one stage. Valving , uses to equalize flow and pressure loads as rotor sets are operated in series to attain high pressures. Speed of rotation is usually limited to less than 2500rpm because of centrifugal forces and subsequent wear at the contact point of vanes against the cam-ring surface..Two vanes may be used in each slot to control the force against the interior of the casing or the cam ring. Dual vanes also provide a tighter seal , reducing the leakage from the discharge side to the suction side of the pump . the opposed inlet and discharge port in this design provide hydraulic balance in the same way as the pump, both these pumps are constant-displacement units. The delivery or capacity of a vane-type pump in gallons per minute cannot be changed without changing the speed of rotation unless a special design is used. Figure shows a variable-capacity sliding-vane pump. It dose not use dual suction and discharge ports. The rotor rums in the pressure-chamber ring, which can be adjusted so that it is off-center to the rotor. As the degree of off-center or eccentricity is changed, a variable volume of fluid is discharged. Figure shows that the vanes create a vacuum so that oil enters through 180 of shaft rotation. Discharge also takesplace through 180 of rotation. There is a slight overlapping of the beginning of the fluid intake function and the beginning of the fluid discharge.Figure shows how maximum flow is available at minimum working pressure. As the pressure rises, flow diminishes in a predetermined pattern. As the flow decreases to a minimum valve, the pressure increases to the maximum. The pump delivers only that fluid needed to replace clearance floes resulting from the usual slide fit in circuit components.A relief valve is not essential with a variable-displacement-type pump of this design to protect pumping mechanism. Other conditions within the circuit may dictate the use of a safety or relief valve to prevent localized pressure buildup beyond the usual working levels.For automatic control of the discharge , an adjustable spring-loaded governor is used . this governor is arranged so that the pump discharge acts on a piston or inner surface of the ring whose movement is opposed by the spring . if the pump discharge pressure rises above that for which the by governor spring is set , the spring is compressed. This allows the pressure-chamber ring to move and take a position that is less off center with respect to the rotor. The pump theb delivers less fluid, and the pressure is established at the desired level. The discharge pressure for units of this design varies between 100 and 2500psi.The characteristics of a variable-displacement-pump compensator are shown in figure. Horsepower input values also shown so that the power input requirements can be accurately computed. Variable-volume vane pumps are capacity of multiple-pressure levels in a predetermined pattern. Two-pressure pump controls can provide an efficient method of unloading a circuit and still hold sufficient pressure available for pilot circuits.The black area of the graph of figure shows a variable-volume pump maintaining a pressure of 100psi against a closed circuit. Wasted power is the result of pumping oil at 100psi through an unloading or relief valve to maintain a source of positive pilot pressure. Two-pressure –type controls include hydraulic, pilot-operated types and solenoid-controlled, pilot-operated types. The pilot oil obtained from the pump discharge cannot assist the governor spring. Minimum pressure will result. The plus figure shows the solenoid energized so that pilot oil assists compensator spring. The amount of assistance is determined by the small ball and spring, acting as a simple relief valve. This provides the predetermined maximum operating pressure.Another type of two-pressure system employs what is termed a differential unloading governor. It is applied in a high-low or two-pump circuit. The governor automatically, Through pressure sensing, unloads the large volume pump to a minimum deadhead pressure setting. Deadhead pressure refers to a specific pressure level established as resulting action of the variable-displacement-pump control mechanism. The pumping action and the resulting flow at deadhead condition are equal to the leakage in the system and pilot-control flow requirements. No major power movement occurs at this time, even though the hydraulic system may be providing a clamping or holding action while the pump is in deadhead positionThe governor is basically a hydraulically operated, two-pressure control with a differential piston that allows complete unloading when sufficient external pilot pressure is applied to pilotunload port.The minimum deadhead pressure setting is controlled by the main governor spring A. the maximum pressure is controlled by the relief-valve adjustment B. the operating pressure for the governor is generated by the large-volume pump and enters through orifice C.To use this device let us assume that the circuit require a maximum pressure of 1000psi, which will be supplied by a 5-gpm pump. It also needs a large flow (40gpm) at pressure up to 500psi; it continues to 1000pso at the reduced flow rate. A two-pump system with an unloading governor on the 40-gpm pump at 500psi to a minimum pressure setting of 200psi (or another desired value) , which the 5-gpm pump takes the circuit up to1000psi or more.Note in figure that two sources of pilot pressure are required. One ,the 40-gpm pump, provides pressure within the housing so that maximum pressure setting can be obtained. The setting of the spring, plus the pressure within the governor housing, determines the maximum pressure capacity of the 40-gpm pump. The second pilot source is the circuit proper, which will go to 1000psi. this pilot line enters the governor through orifice D and acts on the unloading piston E . the area of piston E is 15 percent greater than the effective area of the relief poppet F. the governor will unload at 500psi and be activated at 15percent below 500psi, or 425psi. By unloading, we mean zero flow output of the 40-gpm pump.As pressure in the circuit increases from zero to 500psi, the pressure within the governor housing also increases until the relief-valve setting is reached, at which time the relief valve cracks open, allowing flow to the tank.The pressure drop in the hosing is a maximum additive value, allowing the pump to deadhead. Meanwhile, the system pressure continues to rise above 700psi, resulting in a greater force on the bottom of piston E than on the top. The piston then completely unseats poppet F, which results in a further pressure drop within the governor horsing to zero pressure because of the full-open position of the relief poppet F. flow entering the housing through orifice is directed to the tank pass the relief poppet without increasing the pressure in housing. The deadhead pressure of the 40-gpm pump then decreases to the lower set value. Thus , at the flow rate to the unloading governor ,the 40gpm pump goes to deadhead. The flow rate to the circuit decreases to 5gpm as the pressure to 1000psi, the 5-gpm pump is also at its deadhead setting, thus only holding system pressure.The 4-gpm pump unloads its volume at 500psi. It requires a system pressure of 600psi to unload the 40-gpm pump to its minimum pressure of 200psi. the 600-psi pilot supply enters through orifice D and acts on the differential piston E. The pumps volume is reduced to zero circuit-flow output at 500psi. The additional 100-psi pilot pressure is required to open poppet F completely and allow the pressure within the housing to decrease to zero.As circuit pressure decreases ,both pumps come back into service in a similar pattern.CNC machine toolsWhile the specific intention and application for CNC machines vary from one machine type to another, all forms of CNC have common benefits. Here are but a few of the more important benefits offered by CNC equipment.The first benefit offered by all forms of CNC machine tools is improved automation.The operator intervention related to producing work pieces can be reduced or eliminated. Many CNC machines can run unattended during their entire machining cycle, freeing the operator to do other tasks. This gives the CNC user several side benefits including reduced operator fatigue, fewer mistakes caused by human error, and consistent and predictable machining time for each workpiece. Since the machine will be running under program control, the skill level required of the CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing workpieces with conventional machine tools.The second major benefit of CNC technology is consistent and accurate workpieces. Today's CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical workpieces can be easily produced with precision and consistency.A third benefit offered by most forms of CNC machine tools is flexibility. Since these machines are run from programs, running a different workpiece is almost as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change over. Since these machines are very easy to set up and run, and since programs can be easily loaded, they allow very short setup time. This is imperative with today's just-in-time (JIT) product requirements.Motion control - the heart of CNCThe most basic function of any CNC machine is automatic, precise, and consistent motion control. Rather than applying completely mechanical devices to cause motion as is required on most conventional machine tools, CNC machines allow motion control in a revolutionary manner2 . All forms of CNC equipment have two or more directions of motion, called axes. These axes can be precisely and automatically positioned along their lengths of travel. The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be commanded through programmed commands. Generally speaking, the motion type (rapid, linear, and circular), the axes to move, the amount of motion and the motion rate (feedrate) are programmable with almost all CNC machine tools.A CNC command executed within the control tells the drive motor to rotate a precise number of times. The rotation of the drive motor in turn rotates the ball screw. And the ball screw drives the linear axis (slide). A feedback device (linear scale) on the slide allows the control to confirm that the commanded number of rotations has taken place3.Though a rather crude analogy, the same basic linear motion can be found on a common table vise. As you rotate the vise crank, you rotate a lead screw that, in turn, drives the movable jaw onthe vise. By comparison, a linear axis on a CNC machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis.How axis motion is commanded - understanding coordinate systems .It would be infeasible for the CNC user to cause axis motion by trying to tell each axis drive motor how many times to rotate in order to command a given linear motion amount4. (This would be like having to figure out how many turns of the handle on a table vise will cause the movable jaw to move exactly one inch!) Instead, all CNC controls allow axis motion to be commanded in a much simpler and more logical way by utilizing some form of coordinate system. The two most popular coordinate systems used with CNC machines are the rectangular coordinate system and the polar coordinate system. By far, the more popular of these two is the rectangular coordinate system.The program zero point establishes the point of reference for motion commands in a CNC program. This allows the programmer to specify movements from a common location.If program zero is chosen wisely, usually coordinates needed for the program can be taken directly from the print.With this technique, if the programmer wishes the tool to be sent to a position one inch to the right of the program zero point, X1.0 is commanded. If the programmer wishes the tool to move to a position one inch above the program zero point, Y1.0 is commanded. The control will automatically determine how many times to rotate each axis drive motor and ball screw to make the axis reach the commanded destination point . This lets the programmer command axis motion in a very logical manner.All discussions to this point assume that the absolute mode of programming is used. The most common CNC word used to designate the absolute mode is G90. In the absolute mode, the end points for all motions will be specified from the program zero point. For beginners, this is usually the best and easiest method of specifying end points for motion commands. However, there is another way of specifying end points for axis motion.中文译文旋转泵旋转泵应用于不同的设计中，在流体动力系统中极其常用。
外文翻译--泵的概述
外文原文：Pump's outlineThe pump is the application very widespread general machinery, may say that is place of the fluid flow, nearly has the pump in the work. Moreover, along with science's and technology's development, pump's application domain is expanding rapidly, according to the over-all state statistics, pump's power consumption approximately composes the national total output of electrical energy 1/5, obviously the pump is natural consumes energy the wealthy and powerful family. Therefore, raises the pump technical level to save the energy consumption to have the important meaning.First. Centrifugal pump's principle of workThe drive leads impeller revolving through the pump spindle to have the centrifugal force, under the centrifugal action of force, the liquid is flung along the leaf blade flow channel to the impeller export, the liquid sends in after the volute collection the eduction tube. The liquid obtains the energy from the impeller, • causes the pressure energy and the speed can increase, and depends upon this energy the hydraulic transport to the operating location. while the liquid is flung which exports to the impeller, the impeller eye center has formed the low pressure, • has had the differential pressure in the imbibition pot and between the impeller center liquid, in the imbibition pot's liquid under this differential pressure function, after inhales the pipeline and pump's suction chamber unceasingly enters in the impeller.Second, centrifugal pump's structure and main spare partA centrifugal pump mainly by the pump body, the impeller, the packing ring, the rotation axis, the axis seals parts and so on box to be composed, some centrifugal pumps are also loaded with the guide pulley, the inducer, the balance disc and so on.1. Pump body: Namely pump's shell, including suction chamber and delivery chamber.①Suction chamber: Its function is enables the liquid to flow in evenly the impeller.②Delivery chamber: Its function collects the liquid, and sends in it the subordinate impeller or guides the eduction tube, at the same time reduces the liquid the speed, causes the kinetic energy to further turn the pressure energy. The delivery chamber has the volute and the guide vane two forms.2. Impeller: It is in the centrifugal pump transmits the energy for the liquid only part, the impeller with the bond fixation on the axis, leads revolving alongwith the axis by the prime mover, passes to through the leaf blade prime mover's energy the liquid.Impeller classification:①According to liquid inflow classification: Single suction impeller (in impeller's one side has an entrance) and double attracts the impeller (liquid from impeller's lateral symmetry liudao impeller passage).②Is opposite according to the liquid in centerline's flow direction classification: Runoff type impeller, axial-flow propeller and interflow type impeller.③According to impeller's structural style classification: Shrouded impeller, open type impeller and semi-opened impeller.3. Axis: Is transmits the mechanical energy the important components, the • prime mover's torque passes to the impeller through it. The pump spindle is the pump rotor's major parts, on the axis is loaded with components and so on impeller, axle sleeve, balance disc. The pump spindle depending on the both sides bearing supporting, makes the high speed rotation in the pump, thus the pump spindle in a big way wants the bearing capacity, to be wear-resisting, to be anti-corrosive. Pump spindle's material selects the carbon steel or the alloy steel and after the quenching and retempering treatment generally.4. Packing ring: Is installs in the rotation impeller and the static pump housing (center-section and guide vane's assembly) between packing assembly. It is function is through controls between the two gap method, increases in the pump between the high and low pressure cavity the fluid flow resistance, reduces divulging.5. Axle sleeve: The axle sleeve is uses for to protect the pump spindle, causes it not to corrode and the attrition. When necessity, the axle sleeve may replace.6. Axis seals: The pump spindle and around packing box between end cover's installs short for axis to seal, mainly prevents in pump's liquid divulging and the air enters in the pump, achieves seals and prevents the air admission to cause the pump cavitation goal. the axis seals form: Namely has skeleton's rubber seal, the packing seal and the mechanical seal.7. axial force balancing unit.Third. Centrifugal pump's prime task parameter1. Current capacity: Namely the pump in unit of time discharges the liquid quantity, usually indicated with the Unit of volume that mark Q, the unit has m3/h, m3/s, l/s and so on,2. Lifting: The transportation unit weight's liquid (pump suction flange) (pump discharge flange) from the pump inlet place to the pump exit, its energy's increment, indicated with H, the unit is m.3. Rotational speed: Pump's rotational speed is the pump each minute revolving number of times, expressed with N. Electrical machinery rotational speed •N generally about 2900 n/min.4. Net positive suction head: Centrifugal pump's net positive suction head isNPSH • uses the expressed that pump's performance's main parameter,rsymbolic representation.5. Power and efficiency: Pump's power input is shaft power P, is also electric motor's output. Pump's output is the active power.Fourth, pump proper energy lossPump mechanical energy which obtains from the prime mover, has a part to transform into the liquid energy, but another part because in the pump consumes loses. In the pump all losses may divide into the following several items: 1. Hydraulic loss by the liquid in pump impact, the turbulent flow and the surface friction creates. The impact and the eddy current loss are because the liquid flow change direction produces. The liquid flows through the flow channel general meeting which contacts to present the surface friction, from this produces the energy loss is mainly decided by flow channel's length, the size, the shape, the surface roughness, as well as liquid speed of flow and characteristic.2. Volumetric loss: volumetric loss was already obtained the energy liquid to have a part to flee the result which in the pump the class and leaked outward.is 0.93～0.98 generally. Improves the packing Pump's volumetric efficiencyvring and the seal structure, may reduce the leakage, raises the volumetric efficiency.3. Mechanical loss mechanical loss refers to the impeller lap side and the pump housing friction loss between the liquid, namely the disc loses, as well as pump spindle when packing, bearing and balancing unit and so on mechanical part movement friction loss, generally before primarily.Fifth, pump's speed change--Proportionality law1. Centrifugal pump's speed change:A centrifugal pump, when its rotational speed change, its rated flow, lifting and the shaft power will have the change according to the certainproportion relations. At present, uses the frequency conversion velocity modulation electrical machinery to realize centrifugal pump's speed change, is a new important energy conservation way. 2. proportionality law expression:2121n n Q Q = 22121⎪⎪⎭⎫ ⎝⎛=n n H H 32121⎪⎪⎭⎫ ⎝⎛=n n N N In the formula, Q, H, N-- pump's rated flow, lifting and shaft power Thesubscript 1,2 express the different rotationalspeed separatelyn-- rotational speedSixth, centrifugal pump's ratio rotationCompared to the rotation is the comprehensive parameter which derives by the law of similarity, it is the operating mode function, to a pump, the different operating mode has differently compared to the rotation, for ease of carries on the comparison to the different type pump's performance and the structure, the application optimum condition (the peak efficiency spot) the ratio rotation represents this pump.When chooses the pump, may according to job requirement Q, H and unifies electrical machinery's rotational speed, calculates the n s number, determines pump's type approximately. At that time, 30<s n used the positive displacement pump generally, at that time, 30>s n used the centrifugal pump, the interflow pump, the axial flow pump and so on. Seventh,centrifugal pump'scavitation andinspirationcharacteristic1.Cavitation phenomenonsThe pumping station transportation medium's liquid condition and the gas are can transform mutually, the transformed condition is the pressure and the temperature. Under certain temperature, the liquid starts the critical pressure which vaporizes for the vaporization pressure. The temperature is higher, the liquid vaporization pressure is higher. Pump when revolution, if its overflow part local region (for example impeller blade import later somewhere), the liquid absolute pressure drops when pulled out delivers the liquid at that time under the temperature vaporization pressure, the liquid then in this place starts to vaporize, the bubble formation (air bubble internal pressure approximately wasequal to vaporization pressure). When these air bubbles along with liquid flow forward motion to high pressure region, down to around the air bubble high-pressured liquid causes the air bubble to reduce suddenly congeals. While air bubble vanishing, the liquid particle by the high speed packing hole, occurs hits mutually forms the intense pressure surge, causes the overflow part to receive the corrosion and the destruction. The above process is called the cavitation.2. Cavitation will cause serious results:(1). has the vibration and the noise.(2). is influential to pump's operating performance: When the cavitation develops the certain extent, the • steam bubble produces massively, will stop up the flow channel, will cause pump's current capacity, lifting, the efficiency and so on obviously to drop.(3). will have the destruction to flow channel's material quality: Is mainly nearby the leaf blade entrance the metal weary disintegration.3. centrifugal pump's inspiration characteristic:(1). Pump has the cavitation basic condition is: Under leaf blade entrance lowest liquid flow pressure k P <= this temperature liquid vaporization pressure v P .(2). effective net positive suction head: The pump entry (potential head is the entire flood peak which zero) the liquid has subtracts the value which the vaporization delivery head remains only, with expression.(3). pump essential net positive suction head: Liquid flow from pump inlet to impeller in minimal pressure point of force K place complete energy loss, with expression.(4). With r NPSH and a NPSH difference and relation:a NPSH >r NPSH Pump not cavitationa NPSH =r NPSH The pump starts the cavitationa NPSH <r NPSH Pump serious cavitation(5). regarding a pump, to guarantee that its safe operation does not have the cavitation, must the net positive suction head also be supposed to add asecurity allowance regarding the pump, therefore, pump's permission net positive suction head is:[]NPSH=()c1.1~NPSH5.14. Enhances the centrifugal pump anti-cavitation performance themethod to include:NPSH, is machine the pump (1). I mprovement machine pump structure, reducesrdesign question.(2). Enhancement installment effective net positive suction head. Most mainly the most commonly used method uses the irrigation inspiration installment.In addition, reduces the inspiration pipeline resistance loss as far as possible, reduces the liquid the saturated steam tension, namely when design inspiration pipeline selects caliber big as far as possible, length short, the bend and valve few, transportation liquid temperature as far as possible low and so on measures, may enhance the installment the effective cavitation remainder.5. axial force balancing unit(1). axial force production reason①Around because the impeller the both sides the fluid pressure distributed situation different (wheel cap lateral pressure is low, • wheel disk pressure high) causes axial force A1, its direction for from impeller back side direction impeller eye.②The fluid flows in and flows out dynamical reaction A2 which impeller's direction and the speed different produce, its direction and A1 are opposite, therefore line shaft directive force A=A1-A2, the direction is ordinary and A1 same (general A2 is small).(2). Axial force balanced①Uses double attracts the type impeller: The impeller lateral symmetry, the fluid from the both sides inspiration, the axial force automatic counter-balance achieves balanced.②Opens the balancing hole or installs the compensating pipe:A: Opens several balancing holes in the impeller wheel disk photograph well regarding the induction port place.B: After order to avoid the balancing hole, because the mainstream is disturbed increases the hydraulic loss, may suppose the compensating pipe to replace the balancing hole, namely uses an acorn tube leading-in point pressure to the wheeldisk back side.③Uses the balanced leaf blade: Casts several radial direction muscle piece at the back of the leaf wheel disk, the • muscle piece drives at the back of the impeller in the gap fluid to accelerate to revolve, increases the centrifugal force, •, thus causes at the back of the impeller the pressure obviously to reduce.④Using thrust bearing withstanding axial force. Generally in the small single suction pump the thrust bearing may withstand the complete axial force, prevents the pump spindle to flee moves.Eighth. centrifugal pump's operating procedure1. Centrifugal pump starts the inspection(1) Electrical machinery overhaul, before connecting the shaft coupling, inspects electrical machinery's rotation direction first to be whether correct.(2) inspection pumps out the inlet line and the attached pipeline, the flange, the valve installs whether to meet the requirement, foot bolt and grounding to be whether good, whether the shaft coupling does install.(3) jigger inspection, rotates whether normally.(4) inspection lubricating oil oil level is whether normal, refuels without the oil, and inspects the lubricating oil (fat) oil material nature.(5) turns on various cooling water valve, and inspects the pipeline to be whether unimpeded. Attention cooling water not suitable oversized or too small, will create the waste oversized, too small, then the cooling performance will be bad. Generally the cooling current of water becomes the striation(6) dozen of pumping's inlet valve, closes pump's outlet valve, and turns on the pressure gauge valve.(7) inspection machine pump's seal condition and oil seal opening. attention: The hot oil pump wants evenly before the start preheating.2. centrifugal pump's start(1) all operates the inlet valve, closes the outlet valve, the starting dynamo.(2), when the pump outlet pressure is bigger than the service pressure, inspects each work on six cylinders, turns on the outlet valve gradually.when(3) starting dynamo, if the start or has time the unusual sound, should the dump inspection, after eliminating the breakdown, immediately only then starts.when(4) start, pays attention to the human not to face the shaft coupling, by against departs offends somebody.3. the centrifugal pump stops the pump to operate(1) to close pump's outlet valve slowly.(2) shuts off electrical machinery's power source.(3) closes the pressure gauge valve.(4) parking, cannot stop the cooling water immediately, should pump's temperature only then cut off the water supply falling to 80 degrees below.(5) according to the need, closes the inlet valve, the pump body blows off.4. centrifugal pump operates when matters needing attention(1) centrifugal pump when revolution avoids the idle operation.(2) avoids when closes the outlet valve the long time revolution.(3) refuses the water used battery charger.the(4) centrifugal pump must in close in outlet valve's situation to start.中文译文：泵的概述泵是应用非常广泛的通用机械，可以说是液体流动之处，几乎都有泵在工作。
旋转机械故障的研究及常见故障的振动诊断毕业课程设计外文文献翻译、中英文翻译
1.英文文献翻译1.1英文文献原文题目Chapter 2 Research and rotating machinery fault vibration fault diagnosis of common.Rotating machinery are those main function is to be completed by the rotary movement of mechanical equipment, such as steam turbines, gas turbines, generators, motors, centrifugal blowers, centrifugal compressor pumps, vacuum pumps and a variety of slow growth of the gears and other machinery equipment, all belong to the scope of rotating machinery. Rotating machinery is the application of machinery and equipment most widespread, the number of the largest and most representative one of machinery and equipment, especially in electric power, petrochemical, metallurgy, machinery, aviation, nuclear industry and other industries, rotating machinery is a significant share an important position.2.1 Classification of Rotating Machinery VibrationRotating machinery vibration failure was classified as a major form of failure, according to different classification methods, a variety may be as follows1.By vibration frequency classification(1) Vibration frequency;(2) Harmonic vibration, for example, two octave, 3 octave vibration;(3) The entire baseband frequency scores (such as 1 / 2, 1 / 3, etc.)of the vibration;(4) Frequency and baseband into the relationship between a certain percentages (eg 38% ~ 49%) of the vibration;(5) ultra-low-frequency (vibration frequency 5Hz below) vibration;(6) Ultra-high frequency (vibration frequency in 10 kHz and above) Vibration2. Amplitude direction according to classification(1) Diameter (horizontal) to the vibration that is the direction along the shaft diameter of the vibration is generally divided into horizontal vibration straight vibration.(2) Axial vibration, that is, the direction along the axis of vibration cutting;(3) Tensional vibration, that is, the vibration along the shaft rotation direction.3. by vibration of the reasons for classification(1) The vibration caused by rotor imbalance;(2) Shaft misalignment caused by vibration;(3) Sliding bearing and crankshaft vibration caused by eccentricity;(4) The machine parts caused by loose vibration;(5) Friction (such as seal friction, the rotor and the stator friction, etc.) caused by vibration;(6) Bearing damage caused by vibration;(7) Sliding bearing oil whirls and oil whip caused by vibration;(8) Air power and hydraulic vibration caused by factors such as;(9) Bearing stiffness asymmetry caused by vibration;(10) Electrical aspects of the reasons for the vibration caused by4. Vibration occurred by the site classification(1) Rotor or shaft (including the journal, shaft profile vane, etc.)vibration;(2) Bearings (including the film sliding bearings and rolling bearing) vibration;(3) Shell, bearing vibration;(4) Infrastructure (including aircraft seats, table, or bracket, etc.) vibration;(5) Other areas such as valves, pipe stem, and a variety of structural vibration, etc.In addition, if according to the characteristics and forms of vibration, but also separation of synchronous vibrations (forced vibration) and sub-synchronous (self-excited vibration), etc... Due to vibrations caused by the failure of its manifestations are diverse, in order to accurately identified the cause failures cause - generally speaking, have to rely on signal processing techniques and vibration theory, and other modern methods and means to conduct a comprehensive and integrated analysis and in accordance with the gradual accumulation of experience in the specific circumstances, the only way to achieve fault diagnosis success. Failure of rotating machinery and therefore must be characterized by research.2.2 The characteristics of rotating machinery faultThe implementation of fault in the dynamic monitoring of rotating machinery, we must pay attention to other features:2.2.1 Rotor FeaturesThe rotor component is the core of rotating machinery and equipment, which is fixed by the shaft and the installation of various types of circular discoid components (such as coupling, bearings, impeller, gear, balance disk, pulley, wheel, flywheel, etc.), formed. As the entire rotor in high-speedrotation movements, so its manufacture, installation, commissioning, maintenance and management have a very high demand. If you had problems with one of these components, or in connection with a change in part an exception occurred, they immediately drew a strong vibration unit. It can be said of dynamic monitoring rotating machinery monitoring and diagnosis is mainly the rotor state of motion.2.2.2 The frequency characteristics of rotating machinery vibrationMost of rotating machinery vibration signals is periodic signals, quasi-periodic signal, or a stationary random signal. Failure of rotating machinery vibration characteristics have a common point, namely, the failure of their characteristic frequency related with the rotor speed is equal to the rotor rotation frequency (referred to as transfer frequency, also known as frequency) and its octave or sub-frequency. Therefore, the analysis of vibration signals of the frequency and turn the relationship between the frequencies of rotating machinery fault diagnosis of a key.2.2.3 for rotating machinery vibration monitoring the main wayVibration signal analysis is the basic method for monitoring rotating machinery, the main three-pronged approach to obtain monitoring information1. Analysis of rotating machinery vibration frequency of each type of fault has its own characteristic frequency at the scene to make the frequency of the vibration signal analysis is the diagnosis of rotating machinery of the most effective method. Frequency speed of rotating machinery is like a "military demarcation line," the entire band is divided into sub-and super-asynchronous asynchronous vibration frequency of vibration of two sections, to seize this point, helps us to analyze and judge the fault2. Analysis of amplitude and direction of features in some cases(certainly not all occasions) different types of rotating machinery fault vibration on the performance characteristics of a clear direction. Therefore, the vibration of rotating machinery measurements, as long as conditions permit, the general measure of each measuring point should be horizontal, vertical and axial three directions, as in different directions to provide us with a different fault information. Leakage measured in one direction, you may losea message.3. Analysis of the relationship between the amplitude changes with the speed of a considerable portion of rotating machinery fault vibration amplitude and speed changes are closely related, so on-site measurements, when necessary, to create conditions for as much as possible, in the process of changing the speed amplitude measurement of the machine value.2.3 Rotating Machinery Vibration Fault DiagnosisAs mentioned earlier, equipment fault diagnosis is essentially a pattern classification are based on test analysis obtained on the state information, and grouped into a certain type of equipment failure. Therefore, the characteristics of each type of fault must have sufficient understanding. Equipment diagnostics development today, the people through a large number of experimental studies and a wide range of diagnostic practice, for a variety of devices (especially rotating machinery) of the failure mechanism, fault type and its characteristics have a considerable understanding of understanding. Statistics show that, with the production of a different nature, the type of equipment used is also different, so the proportion of various types of failures is also inconsistent. Here are several common fault diagnosis of rotating machinery vibration characteristics, diagnostic methods and examples.2.3.1 ImbalanceAccording to the information that various types of rotating machinery failure due to imbalance of about 30%, we can see that the machine rotor imbalance caused by rotating machinery vibration is a common multiple faults. To fully understand and grasp the characteristics and mechanism of unbalanced fault diagnosis is very important.1. The causes of imbalances caused by rotor imbalance are many reasons, such as:① unreasonable because it is designed geometry caused by different heart, or deviate from the geometric center line of rotary valve shaft;② Manufacture, installation error;③ Rotor material uneven, or heat unevenly;④ Rotor initial bending;⑤ Work medium in the solid impurities in the rotor on the uneven deposition;⑥ Rotor in the course of corrosion, wear and tear;⑦ Rotor parts loose, fall off.2. Rotor imbalance may lead to consequences for the flexible rotor may also generate additional degree of damage due to dynamic inertia of the centrifugal force caused by imbalance. For various reasons caused by rotor unbalance fault is a basically the same pattern. To sum up, the rotor imbalance may lead to the following undesirable consequences:(1) The rotor caused by repeated bending and internal stress, causing the rotor fatigue, even lead to rotor fault;(2) To enable the machine in operation during the excessive vibration and noise, so that it will accelerate the wear of bearings and other componentsto reduce life expectancy and efficiency of the machine;(3) Through the vibration of the rotor bearings, machine transmits to the base blocks and buildings, resulting in deterioration in working conditions.3. Rotor imbalance generally include the following four cases(1) Static unbalance;(2) double-sided imbalances;(3) Static and dynamic imbalance;(4) Dynamic imbalance. for example:2-1:Among them, static imbalance is an imbalance in the cross section, while the remaining three kinds of imbalance is an imbalance on the number of sections, and each inspired by a cross-section due to imbalances in the lateral vibration and static unbalance is the same as the mechanism of. In other words, the cross section generated by the phase and amplitude of vibration and its size may vary, but the vibration frequency is exactly the same, are the first-order rotation frequency (fundamental frequency),2-1f0 - a first-order frequency of the rotor, ie rotor fundamental frequency (Hz); n - rotor speed (r / min).Unbalanced rotor in rotation will produce a cycle of change was the imbalance in power, the cycle just that, as shown in Figure 2-2.With the rotor unbalance vibration signal, its time waveform and frequency spectrum of the typical curves shown in Figure 2-3, and generally has the following characteristics:(1) The vibration signal of the original time waveform of sine wave;(2) The frequency spectrum of vibration signal, its fundamental frequency component and a significant proportion, while other components such as frequency-doubling the proportion of relatively small.(3) In the process of speeding up or down, when (that is, when speed is less than the critical speed), the amplitude increases with the increase in W, both bearing the same direction of the force, while in the later, the amplitude increases with the W, but will decreases, and gradually tends to a smaller valuation.4. The basic method of diagnosis of unbalanced fault diagnosis of unbalanced faults, we must first analyze the signal frequency components, the existence of transponder prominent situation. Second, look at the direction of vibration characteristics, if necessary, further analysis of the changes in amplitude as speed or measuring the phase. Because the latter two tests carried out too much trouble to stop the problem involved, which in general is difficult in the production of the site done, and only to a non-for not only had to do when, but time can not be delayed too long.2.3.2 MisalignmentAs the rotor and turn on the sub-shaft connection between the use of connecting devices install properly, or due to bearing centerline deviation, or offset, or because the rotor bending, rotor and bearing clearance and load transfer in the bearing after the deformation and other reasons, tend to result in between the rotor (shaft) to the poor, resulting in vibration and lead to mechanical failure. It is also one of the very common mechanical failures .1. Shaft misalignment of the shaft does not include the three forms of coupling misalignment and bearing right in both cases, here we only discuss the coupling (shaft) misalignment. Coupling does not usually possesses the following three forms,For example2-4:(1) Parallel misalignment, this time through the rotor axis lines in parallel displacement.(2) The angle misalignment, this time to switch on the two axis lines intersect, or angle displacement.(3) Parallel synthesis misalignment angle, this time two lines intersect the rotor axis of displacement.Figure 2-5 shows the shaft vibration caused by misalignment angle parallel to the simple diagramIn general, the rotor shaft misalignment can cause additional load on the bearings, resulting in the bearing load between the re-allocation would lead to serious bearing damage caused by a strong vibration. On the other hand, with the coupling on both sides of bearing the load changes that may cause the system critical speed of the change in the uneven effects of an increase, giving rise to the coupling fatigue. When the bearing change is large, for the sliding bearing oil film may also cause instability.2. Shaft misalignment of the main features of a typical shaft misalignment radial vibration signal time waveform and frequency spectrum 2-6. And mainly has the following characteristics:(1) The vibration signal of the original time waveform distortion sinewave. (2) The radial vibration frequency spectrum of the signal to a multiplier, and second harmonic components of the main shaft misalignment more serious, and the second harmonic component of the greater proportion, in most cases more than one harmonic component of .(3) The axial vibration of components in the spectrum to octave higheramplitude.(4) Coupling on both sides of the axial vibration is essentially 180 °inverting.(5) A typical trajectory for the banana-shaped axis is precession.(6) Vibration on the more sensitive to changes in load, the generalvibration amplitude increases with the load increase.2.3.3 Rotor CrackIf the rotor rotating machinery are poorly designed (including the improper selection or structure is irrational) or improper processing methods, or the super life of running, it will cause stress concentration leading to cracks. On the other hand, fatigue, creep and stress corrosion can cause micro-cracks in the rotor, plus large change due to the twist and radial loadto form the mechanical stress state, resulting in continuous expansion of these micro-cracks eventually become a macro-crack.1. Three forms of rotor cracks(1) Closed crack. Rotor rotates; the crack was always closed state. When the crack zone in a compressive stress state, would constitute a closed crack, such as the rotor weight is not an unbalanced force smaller or unbalanced force precisely the opposite point to cracks, or uneven quality, moments generated by the rotor is greater than the quality of generated moment and so on. Closed crack little effect on the rotor thrust.(2) Open crack. When the rotor spins, the crack was always open state. Open cracks force the situation is exactly the opposite and closed crack; the crack area is always in tension stress state. Open crack will reduce the stiffness of the rotor, and its stiffness to the different nature of each, so that vibration increased.(3) The opening and closing crack. With the rotation of the rotor movement, crack was open and close alternately state, and generally turn the rotor of each week, the crack will be the corresponding open and closed each time. Crack opening and closing part of the open crack and the crack in the middle of a closed transition state, which is the most complex forms. Figure 2-7 shows the rotor with the opening and closing crack deflection curve diagram.Despite the change in the crack will affect the rotor vibration characteristics, but in most cases is not very sensitive, even the cracks in the rotor has a deep, sometimes hard to find significant changes in the vibration condition. For example, according to theoretical calculations, if there is a change in central depth is equal to 1 / 4 turn on the diameter of the crack, its stiffness is only about 10%, while the changes in critical speed is smaller, only 5%. Therefore, these changes will likely be completely submerged into the other signal, that is, from the observed changes in the natural frequency of the rotor, or when the normal operation of the vibration changes according to the early detection of cracks is very difficult. At present more effective way is to stop the process of measurement and analysis open the rate of change in amplitude.Generally speaking, when there open crack rotor, the rotor will become of all the stiffness of the differences. As a result, the vibration of the rotor with a non-linear nature of the spectrum, in addition to a harmonic component, there are twice, three times to five times the high-harmoniccomponents. Toward the crack, the stiffness of the rotor will be further reduced; a multiplier component, as well as twice or three times or five times, and other first-order harmonic components of the amplitude will be even greater.2. Be passed on to crack the monitoring and diagnosis is divided into three areas(1) Open, stopping when the variation of amplitude versus speed.(2) The impact of crack depth on the amplitude.Under normal circumstances, the vibration spectrum and the second harmonic component of twice the amplitude will increase with the depth of the monotonic crack growth, while the corresponding phase decreased with the increase of crack depth irregular fluctuations. It just can be used to distinguish between normal vibrations caused by imbalance.(3) The crack growth rate.But the crack propagation speed increases as the crack depth to accelerate, with a corresponding rate of increase in amplitude occurs phenomenon. In particular the rapid increase in second harmonic amplitude can often provide crack diagnostic information, so can take advantage of two trends in the changes in the harmonic components to diagnose the rotor cracks.3. Rotor cracks after the general characteristics of(1) The first-order critical speed is smaller than normal, especially when the crack worsens.(2) As the crack and stiffness caused by rotor asymmetry, the rotor speed of the formation of multiple resonance.(3) The crack rotor vibration response, one harmonic component of the degree of dispersion when compared with large crack-free.(4) A constant speed, the doubled, tripled the third harmonic and other components of the amplitude and the phase-order instability, and in particular to highlight the second harmonic component.(5) Due to the stiffness of cracked rotor asymmetry, so that pairs of rotor balancing difficulty.1.2中文翻译第2章旋转机械故障的研究及常见故障的振动诊断旋转机械是指那些主要功能是由旋转运动来完成的机械设备，如汽轮机、燃气轮机、发电机、电动机、离心式鼓风机、离心式压缩机泵、真空泵以及各种减速增速的齿轮传动装置等机械设备，都属于旋转机械范围。
泵类英汉翻译
泵类英汉翻译发一份泵类汉英对照表,请进入!汉语术语英文凹槽groove饱和压力Saturation Pressure保持环retaining ring保护层的形成Protective Layer Formation保护形式Types of Protection保证Guarantee背靠背叶轮泵Back-to-back Impeller Pump背叶片Back Vane泵pump泵测试效率pump test efficiency泵出力pump delivery泵的基础Pump Foundation泵的类型Pump Types泵的排出口Pump Discharge Nozzle泵的使用范围Application Fields for Pumps泵的输出功率Pump Output泵的旋转方向Direction of Pump Rotation泵房pump house(room)泵功率Pump Power泵和输送装置噪音Noises in Pumps and Pumping Installations 泵壳Pump Casings泵内沉积物Deposits in Pumps泵试验台Pump Test Bed泵输出功率的降低Reduction in Pump Output泵输入功率pump input power泵体pump casing泵吸入槽Pump Sump泵吸入管吸上高度pump lift泵吸入口Pump Suction Nozzle泵效率pump efficiency泵效率Pump Efficiency泵芯包pump cartridge泵性能曲线pump performance curve 泵站pumping house泵轴Pump Shaft比例泵proportioning pump比输送功Specific Delivery Work比转数Specific Speed边界层Boundary Layer变矩桨叶Variable Pitch Blade标准泵Standard Pump标准化工泵Standard Chemical Pump标准孔板Standard Orifice Plate标准喷嘴Standard Nozzle标准温度Standard Temperature标准文丘里管Standard Venturi Nozzle 标准压力Standard Pressure标准状态Standard Conditions表面保护Surface Protection表压Manometric Pressure并联运转Parallel Operation伯努利方程BERNOULLI Equation补偿器Compensator补给水泵make-up water pump部分负荷运转Part-load Operation残油输出装置Residual Pump-out Device槽slot测量的不精确性Uncertainty in Measurement 测量技术Measuring Technique测量孔板Measuring Orifice Plate测量偏差Measuring Tolerance测量误差Error of Measurement测量仪器Measuring Device测试转速test speed层流Laminar Flow齿轮泵gear pump齿轮传动泵Geared Pump齿轮箱Gearbox冲击冷凝Shock Condensation冲击压力Impact Pressure冲角Angle of Incidence抽出体积Extraction Volume抽气（吸）泵；真空泵suction pump出口侧盖板（大端盖）discharge cover出口截面Outlet Cross-section出口截面宽度Outlet Width出口弯管Outlet Elbow出口压力discharge pressure初始汽蚀Incipient Cavitation传输损失tansmission loss传送器Transmitter船头推进舵Bow Thruster Rudder船坞泵Dock Pump船用泵Marine Pump大气压Barometric Pressure大气压力Atmospheric Pressure带式过滤器Band Sereen单吸离心泵single-suctoin centrifugal单相交流电Single-phase Alternating Current单叶片叶轮Single Vane Impeller导向叶片Guide Vane导向装置Guide Arrangement低温泵Crygenic Pump低压泵Low Pressure Pump底料泵Sump Pump点蚀Pitting电感应式流量测量Inductive Flow Measurement电功率Electric Power电化学腐蚀Electrochemical Corrosion电机Electric Motor电机电耗Current Consumption of Electric Motors 电机温升Temperature Rise in Electric Motors电机转矩曲线Torque Curve of Electric Motors电解腐蚀Electrolytic Corrosion电缆密封压盖Cable Gland电力驱动Electric Drive电流current电路Electrical Circuits电气开关设备Electrical Switchgear电位序Electrochemical Series电压voltage电压降Voltage Drop顶点Apex定位螺栓fitted bolt动力液流Motive Water Flow动力粘度Dynamic Viscosity动量矩定理Theorem of Momentum动平衡Dynamic Balancing动下室排水泵Cellar Drainage Pump动压力Dynamic Pressure对开的润滑油密封split oil seal对轮the coupling对轮防护罩the coupling guard对轮螺栓coupling nut多级泵Multistage Pump多流式泵Multiflow Pump恩氏粘度Degrees Engler阀门和管件Valves and Fittings法兰结构Flange Construction反向流动Reversal of Flow反应堆泵Reactor Pump反转转速Reverse Rotational Speed防爆Explosion Protection防反转装置Reverse Rotation Locking Device 防腐Corrosion Protection防护装置guard放射Emission非堵塞式叶轮Non-clogging Impeller非扰动管道长度Undisturbed Length of Piping 非稳定流Non-steady Flow非稳定扬程曲线Unstable Throttling Curve费鲁德准数FROUDE Number费用Costs复算Re-evaluation干式安装Dry Installation干运转Dry Running高度Height高速离心泵High Speed Centrifugal Pump高压泵High Pressure Pump隔膜泵diaphragm pump隔膜式计量泵diaphragm type metering pump 给水泵feed water pump给水泵Feed Pump工业水泵industrial water pump工作特征Operating Characteristics公称尺寸Nominal Size公称压力Nominal Pressure功work功率power功率power功率测量power measurement功率调节power control功率损失power loss功率因数power factor cosφ供水泵Water Supply Pump固体颗粒的输送Conveying of Solids过流翼型Flow Profile过滤器Filter海水Sea Water海水泵Sea Water Pump海水淡化装置Sea Water Desalination Plant 海水箱Sea Chest 耗水量Water Consumption合适的流量corrected flowrate恒定油位油杯Constant Level Oiler虹吸流动Syphon Flow虹吸装置Syphoning Installation化工泵Chemical Pump化工稳定性表Chemical Stability Table环境保护Environmental Protection环形泵Ring-section Pump环形壳Annular casing回流导向叶片Return Guide Vane回路试验Loop Test混流叶轮Mixed-flow Impeller活塞传送器Piston Transmitter货船油泵Cargo Oil Pump机械传动Mechnical Drive机械密封Mechanical Seal机械效率Mechanical Efficiency基板Baseplate基本方程Fundation基础Foundation基建投资Capital Investment级Stage级间导叶interstage diffuser极数Number of Poles继电器Relay家用供水装置Domestic Water Supply Plant 间隙宽度Clearance Gap Width间隙密封Clearance Gap Seal间隙汽蚀Clearance Gap Cavitation间隙压力Clearance Gap Pressure监测装置Monitoring Device键key键槽keyway交流电Alternating Current角速度Angular Velocity接触器Contactor接通压力Switching-on Pressure节流调节throttling control节流系数throttling coefficient进液室Intake Chamber进液条件Intake Conditions进液弯管Intake Elbow浸蚀Erosion经济可行性计算Economic Viability Calcuation 净正吸入压头NPSH（Net Positive Suction Head)径向力Radial Force径向剖分壳体Radially Split Casing径向推力Radial Thrust径向叶轮Radial Impeller径向轴承journal bearing绝对速度Absolute Velocity卡诺冲击损失Carnot Shock Loss卡普兰弯管Kaplan Elbow铠装泵Armoured Pump抗腐蚀性Corrosion Resistance壳体Casing可抽出性withdrawability可调叶片adjustable vane空气泵Air Pump空气提升泵Air-Lift Pump空心旋涡Hollow Vortex孔板Oriffice Plate孔径比Apertuer Ratio扩压管（圆锥管）Diffuser(Conical Duct)扩压器（导轮）Diffuser(Guide Wheel)冷凝液泵Condensate Pump冷却剂泵Coolant Pump冷却水泵Cooling Water Pump离心泵centrifugal pump离心泵Centrifugal Pump离心泵的安装Installation of Centrifugal Pump离心泵的操作条件Operating Conditions of Centrifugal Pumps 离心泵的操作性能Operating Behaviour of Centrifugal Pumps 离心泵的冲击损失Shock Loss in Centrifugal Pumps离心泵的间隙损失Clearance Gap Loss in Centrifugal Pumps 离心泵的平稳运行Smoop and Quiet Running of Centrifugal Pumps 离心泵的验收试验规范Acceptance Test Codes for Centrifugal Pumps 离心泵的制造材料Construction Material for Centrifugal Pumps离心泵的注水Priming of Centrifugal Pumps离心泵调节Control of Centrifugal Pumps离心泵和驱动设备保养Care of Centrifugal Pumps and Drives 离心泵失衡Out-of-Balance of Centrifugal Pumps离心泵装置Centrifugal Pump Plant离心式鼓风机centrifugal blower离心式滤油机centrifugal oil filter离心式压缩机centrifugal compressor离心水泵centrifugal water pump立式泵vertical pump立式屏蔽泵（筒形泵）Vertical Can-type Pump立轴式井泵Vertical Spindle Well Pump利息支付Interest Payment连续性方程Continuity Equation两相流动Two-phase Flow临界转速Critical Speed of Rotation流程泵Process Pump流程型结构Process Type Construction 流道涡流Channel Vortex流动分离Flow Separation流动功Flow Output流量flowrate流量Flow流量（体积流量）Capacity流量测定Flow Measurement流量测量Capacity Measurement流量调节器Flow Controller流量系数Flow Coefficient流量指示器、流量观察窗flow indicators 流速Flow Velocity流体Fluid流体动力学Fluid Dynamics流体机械Fluid Flow Machine流线Flow Line轮毂比Hub Ratio螺杆泵screw pump(spiral pump)螺纹紧固件threaded fastener马达输出功率motor output power马达输入功率motor input power马达效率motor efficiency迷宫密封labyrinth gland迷宫密封箱体labyrinth gland housing 迷宫式密封Labyrinth Seal密封衬套shaft sleeve内效率Internal Efficiency那维尔－斯托克斯方程NAVIER-STOKES Equation耐酸泵Acid Pump焾Enthalpy能Energy能量级Energy Level逆时针旋转叶轮Counterclockwise Rotating Impeller 凝泵condensate extraction pump凝结水泵condensate transfer pump凝汽器抽气泵condenser air pump牛顿流体NEWTONian Fluid扭力杆T orsion Rod扭力计T orsion Dynamometer欧拉方程EULER Equation排出段Discharge Casing排出管线Discharge Line排出管嘴Discharge Nozzle排出损失Discharge Loss排灌站水泵Drainage Station Punp排气Venting排气阀Vent Valve排水泵Dewatering Pump排水量Water Yield排污泵blowdown pump(sewage pump)排污泵Faeces Pump旁路By-Pass皮带传动Belt Drive皮托管Pitot Tube频率frequency平垫片flat gasket平衡鼓balance drum平衡鼓螺母balance drum nut平衡孔balance'hole平衡液体流量balance water flow平衡装置balancing device平衡状态equilibrium condition平皮带传动flat belt drive屏蔽泵Canned Motor Pump起动Start Up起动过程Starting Process起动时间Starting Time起动转矩Starting T orgue气囊的形成Formation of Air Pockets 气体分离Gas Separation 汽蚀Cavitation汽蚀磨损Cavitation Wear汽蚀噪音Cavitation Noise强制循环泵forced-circulation pump切断压力Switching-off Pressure切换频率Switching Frequency氢指数Hydrogen Exponent清水泵Clean Water Pump驱动Drive热Heat热泵Heat Pump热含量Heat Content热虹吸Thermosyphon热量Quantity of Heat热载体泵Heat Transfer Media Pump热障Thermal Barrier容积泵Positive Displacement Pump入口导叶suction guide入口管嘴Entry Nozzle入口截面Inlet Cross-section入口压力suction pressure入口锥管Entry Cone润滑油泵Lubricating Oil Pump三相电机Three-phase Motor三相电流Three-Phase Current三相制Three-phase System设计工作点Design Duty Point声学Acoustics时间Time视在功率Apparent Power试验台T est Bed手动泵Hand Pump首级内泵壳first stage ring section输送黏性液体黏性泵centrifugal pump handling viscous liquids 甩油环，抛油环oil thrower双缸泵组Twin Pumping Set双流道泵two-channel impeller pump双流道叶轮two-passage impeller双蜗壳Double Volute水厂泵waterworks pumps水锤water hammer水的硬度hardness of water水力效率hydraulic efficiency水流量计water meter水泥壳泵concrete casing pump水喷射water jet水喷射泵water jet pump水温water temperature水下泵underwater pump水下电机underwater motor水下电机泵underwater motor pump水银泵mercury pump水硬度water hardness速度Velocity速度测定Measuring of Speeds速度测量Velocity Measurement速度三角形Velocity Triangle损失系数Loss Coefficient锁紧垫圈、防松垫圈lock-washer探头Probe特性Characteristic特性曲线Characteristic Curve特性因数Characteristic Factor体积流量Volume Flow停转时间Run-down Time通量线Flux Line同步转速Synchronous Speed铜导体Copper Conductor投资评价Capital Servicing透平驱动泵Turbine Driven Pump涂层Coat of Paint推力盘thrust collar推力瓦thrust pad推力轴承撑板thrust carrier ring 推力轴承室thrust bearing housing 托轮Jockey Pulley弯管Elbow弯管壳体泵Elbow Casing Pump卧式泵Horizontal Pump污泥泵Sludge Pump污水泵Sewage Pump无冲击流入Shock-free Entry无泄漏Leak-tightness吸入口Suction Nozzle吸入室Suction Chamber吸入性能Suction Behaviour吸入压头Suction Head吸入叶轮Sution Impeller纤维素Cellulose纤维性物料Fibrous Material相对速度Relative Velocity相合定律Congruence Law相似条件Similarity Conditions相位移Phase Displacement消防泵Fire-fighting Pump消声测量Noise Abatement Measures 销钉、定位销dowel pin 小舌片tab效率复算Efficiency Re-evaluation斜度Steepness斜流叶轮Diagonal Impelier斜盘式泵Swash Plate Pump泄漏出的密封水隔离门（相当于密封水卸荷阀）leak-off isolating valve 泄漏损失Leakage Loss星形轮Star Wheel星形－三角形起动器电路Star-delta Starter Circuit性能图Performance Chart许可公差Warranty Tolerance许可区域Warranty Zone旋流Swirl Flow旋塞阀Cock旋涡泵Peripheral Pump旋涡式叶轮Peripheral Impeller旋转方向Direction of Rotation旋转速度Rotational Speed压差Differential Pressure压降Pressure Drop压力Pressure压力波Pressure Wave压力波动Pressure Surge压力测量Pressure Fluctuation压力测量Pressure Measurement 压力等级Pressure Categories压力给水装置Hydrophor Plant压力计Manometer压力脉动Pressure Fluctuation压力容器Pressure Vessel压力损失Pressure Loss压力损失Head Loss压力系数Pressure Coefficient压头Pressure Head验收试验Acceptance Test扬程head扬程曲线Throttling Curve叶轮impeller叶轮ipeller叶轮impeller叶轮侧面摩擦Impeller Side Friction 叶轮的修整Trimming of Impellers 叶轮叶片Impeller Vane叶轮叶片节距调节Impeller Blade Pitch Adjustment叶片叶片vane叶片角Blade Angle叶片节距调节机构Blade Pitch Adjustment Gear叶片节距调节装置Blade Pitch Adjustment Device叶梢背部切削Cutting Back of Impeller Vane Tips叶栅vane cascade叶栅流动Cascade Flow液化气泵Liquefied Gas Pump液环泵Liquid Ring Pump异步电机Asynchronous Motor阴极保护Cathodic Protection音量级Sound Volume Level音速Sound Velociyt引水级Priming Stage应变测定技术Strain Measurement Technology应力腐蚀（裂纹）Stress Corrosion (Cracking)永久磁铁联轴器Permanent Magnet Coupling用入口导向叶片控制涡流Rotation Swirl Control by Inlet Guide Vanes 油泵Oil Pump油挡oil guard有势流动Potential Flow有效功率Acitive Power有效汽蚀余量n.p.s.h.r有用功率输出Useful Output右旋叶轮right-handed impeller诱导轮Inducer圆弧形叶片Circular Arc Vane圆周速度Peripheral Speed(Circumferential Velocity)运动粘度Kinematic Viscosity运行时数Number or Running Hours再生泵Regenerative Pump脏水泵Dirty Water Pump折旧Amortization振动Vibration正吸入压头positive suction head直径系数Diameter Coefficient直联泵组Close-coupled Pumping Set直流电Direct Current直流电机Direct Current Motor直流平板式起动器Direct Current Face Plate Starter 止动销stop pin纸浆泵Pulp Pump纸浆浓度Pulp Density纸浆输送Conveying of Pulp制造公差Manufacturing T olerance质量Mass质量惯性矩Mass Moment of Inertia质量流量Mass Flow中点线Mid-point Conductor中性线Neutral Conductor中压泵Medium Pressure Pump重力加速度Gravitational Constant重量Weight轴轴承Bearing轴承支架bearing housing轴承支架盖bearing housing cover轴封Shaft Seal轴封环Shaft Sealing Ring轴功率Shaft Power轴颈shaft journal轴流泵axial pump轴流泵Axial Pump轴流叶轮Axial Impeller轴套、衬套gland bush轴推力Shaft Thrust轴向力Axial Force轴向剖分壳体Longitudinally Split Casing 轴向推力Axial Thrust 主循环泵Primary Circulating Pump柱塞泵Plunger Pump转动惯量Moment of Gyration转矩Torque转矩的测定T orque Measurement转速传感器Rotational Speed Transmitter 自动调节Self-regulation自动断路器Self-acting Circuit Breaker自动开关Automatic Switches自耦变压器式起动器Autotransformer Starter 自吸泵Self-priming Pump自由流动泵Free-flow Pump总测量偏差Overall Measuring T olerance总静压头Total Static Head总偏差Overall Tolerance总效率Overall Efficiency总压力Tital Pressure总扬程T otal Headmeasured flowratevelocity headgauge/lever correctiongenerated headseal sleeve nuts短心轴stub axle轴axes轴axis轴axle（U.S.A）轴承衬套bearing bushing（U.S.A）轴肩挡圈；防护罩protecting collar巴氏合金；白合金；轴承合金white metal半贯流式轴流泵；弯管轴流泵angle-type axial flow pump半可调式轴流泵axial flow pump with blades adjustable when stationary 泵轴Pump Shaft泵轴承支架pump bearing bracket长轴深井泵borehole shaft driven(centrifugal) pump长轴深井泵（美）multistage vertical turbine pump衬套；轴套bushing齿形联轴器gear-type coupling出口轴面速度系数；流量系数capacity constant磁力联轴节齿轮泵magnetically coupled gear pump从动螺杆；从动心轴idler spindle从动轴driven shaft从动轴idler shaft弹性盘联轴器flexible disc coupling弹性圆柱销联轴器flexible pin coupling电磁联轴器electromagneic coupling电磁联轴器magneto coupling电磁联轴器magneto-coupling调节轴adjusting spindle副传动轴countershaft spindle副轴；中间轴；从轴auxiliary shaft刚性联轴器solid coupling刚性联轴器；刚性联接rigid coupling功率曲线；轴功率曲线；制动功率曲线brake horsepower curve 贯流泵；直管轴流泵rubular type axial flow pump滚动轴承anti-friction bearing滚动轴承ball/rolling bearing滚动轴承rolling contact bearing滚针轴承needle bearing恒定轴向间隙齿轮泵fixed axial clearance gear pump滑动轴承plain friction bearing滑动轴承sleeve bearing滑动轴承sliding bearing活塞销；轴头销gudgeon pin架；轴承衬套（美）；泵支架（美) frame径向滚柱轴承radial roller bearing径向球轴承radial ball bearing径向轴封radial shaft seal可调式轴流泵axial flow pump with adjustable(or variable)pitch blades 可调式轴流泵propeller pump with adjustable or variable pitch blades 可逆叶片轴流泵axial flow pump with reversible blades可逆叶片轴流泵propeller pump with reversible blades空心轴hollow shaft shaft冷冻装置用无轴封泵glandless pump for refrigerating installation立轴式井泵Vertical Spindle Well Pump联轴器coupling笼形轴承托架bearing bracket lantern笼形轴承托架bearing housing lantern螺纹联轴器screwed coupling米切尔型推力轴承Michell type thrust bearing内轴承泵pump with internal bearing(s)挠性法兰联轴器flexible flange coupling挠性联轴器elastic coupling挠性联轴器flexible coupling挠性轴flexible shaft配流盘式轴向活塞泵flat valve axial piston pump配流盘式轴向活塞泵port plate axial piston pump配流盘式轴向活塞泵valve plate axial piston pump喷水推进轴流泵axial flow pump for water jet propulsion喷水推进轴流泵water jet propulsion axial flow pump偏心轴eccentric shaft强制润滑轴承；压力润滑轴承forced oil lubricated bearing球面推力轴承spherically mounted thrust bearing曲轴crankshaft曲轴防护罩crankguard曲轴防护罩crankshaft guard曲轴箱支座crankcase pedestal曲轴销crank pin驱动轴；传动轴drive shaft全可调式轴流泵axial flow pump with blades adjustable in operation 全可调式轴流泵axial flow pump with variable piteh blades水润滑轴承water lubricating bearing套筒联轴器sleeve coupling推力滚柱轴承thrust roller bearing推力球轴承ball thrust bearing推力轴承thrust bearing推力轴承；扇形块thrust bearing segment推力轴承扇形块thrust bearing pad外轴承泵pump with external bearing(s)万向轴cardan shaft无轴封泵glandless pump无轴封计量泵glandless metering pump橡胶轴承rubber bearing斜垫轴向推力轴承tilting pad axial thurst bearing斜缸型轴向柱塞泵tilting cylinder block type axial plunger pump 斜盘式轴向活塞泵cam plate type axial piston pump 斜盘式轴向活塞泵swash plate axial piston pump斜盘式轴向活塞泵wobble plate axial piston pump斜置轴流泵inclined axial flow pump斜轴式轴向活塞泵angle-type axial piston pump斜轴式轴向活塞泵bent axis axial piston pump旋涡轴线eddy axis旋涡轴线vortex axis压入式轴承盖pressed-in type bearing cover叶轮轴面形状；工作轮图profile of the impeller液体动力轴承hydrodynamic bearing永久磁铁联轴器Permanent Magnet Coupling油环轴承ring lubricating bearing油环轴承ring oiling bearing油脂润滑轴承grease lubricated bearing支轴销；支点销fulcrum pin支座；轴架pedestal中间心轴idler axle中间心轴intermediate axle中间轴；副轴；从轴counter shaft中间轴；副轴；从轴intermediate shaft轴shaft轴；心轴；锭子spindle轴承bearing轴承Bearing轴承衬（套）bearing bush轴承衬套bearing cartridge轴承衬套bearing insert轴承端盖bearing end cover轴承盖bearing cover轴承合金bearing alloy轴承架bearing bracket轴承架bearing pedestal轴承架bearing spider轴承架；泵托架headstock轴承架固定式泵pump with bearing bracket轴承浸泡试验；轴承泡胀试验bearing swelling test 轴承冷却室bearing cooling chamber轴承螺母bearing nut轴承套bearing sleeve轴承体；轴承箱bearing box轴承托架箱bearing bracket housing轴承瓦；轴承衬垫；轴承衬套bearing line轴承吸水试验bearing absorption test轴承箱；轴承体bearing housing轴承座bearing carrier轴对称axial symmetry轴对称；旋转对称rotational symmetry轴对称流axisymmetrical flow轴封shaft seal轴封Shaft Seal轴封环Shaft Sealing Ring轴功率；制动功率；制动马力brake horsepower轴护套Shaft Protecting Sleeve轴护套shaft tunnel tube轴护套（美）shaft enclosing tube轴肩挡圈loose(shaft) collar轴肩挡圈shaft collar轴肩挡圈shoulder ring轴颈neck journal轴颈shaft neck轴颈axle journal轴颈；期刊journal轴颈套；填料衬套neck bush轴流泵Axial Pump轴流泵；螺桨泵axial flow pump轴流泵叶轮室propeller bowl轴流式涡轮机axial-flow turbine轴流式叶轮axial flow impeller轴流叶轮Axial Impeller轴流增压器axial flow booster轴马力；轴功率shaft horsepower轴面流线meridian streamline轴面速度meridional velocity轴面投影图elevation view轴配流径向活塞泵pintle valve radial peston pump 轴配流径向活塞泵valve spindle radial piston pump 轴套shaft wearing sleeve 轴套Axis Guide轴套shaft sleeve轴套；套（筒）sleeve轴套拆卸器sleeve puller轴瓦；轴承箱；轴承体bearing sheet轴位指示器shaft position indicator轴吸泵axial inlet pump轴向单吸液环泵axial single entry liquid ring pump轴向导叶axial diffuser轴向滑移aixal slip轴向活塞泵axial piston pump轴向加速度axial acceleration轴向间隙axial clearance轴向间隙压力补偿齿轮泵gear pump with pressure-dependent axial clearance 轴向间隙压力补偿齿轮泵gear pump with pressurized side plate轴向力axial force轴向力Axial Force轴向流动axial flow轴向磨损指示器axial wear indicator轴向剖分壳体Longitudinally Split Casing轴向双吸液环泵axial double entry liquid ring pump轴向速度axial velocity轴向推力axial thrust轴向推力Axial Thrust轴向吸入泵axial suction pump轴向压力axial pressure轴向柱塞泵axial plunger pump主动螺杆；驱动心轴driving spindle主动轴driving shaft柱销联轴器pin coupling爪形联轴器claw coupling爪形联轴器dog coupling爪形联轴器jaw coupling锥形联轴器cone(type) coupling锥形联轴器taper coupling子午面；轴面meridian plane自锁轴套self-locking sleeve半贯流式轴流泵；弯管轴流泵angle-type axial flow pump半可调式轴流泵axial flow pump with blades adjustable when stationary 泵pump泵房pump house泵盖casing cover泵缸pump barrel泵缸pump cylinder泵缸套pump barrel line泵缸套pump cylinder line泵缸体pump cylinder block泵工况pump operating condition泵工况pump operating duty泵体pump body泵体衬套pump body insert泵体衬套pump casing insert泵托架pump bracket泵站设计design of pump station泵罩outer pump mantle泵支架pump bearing lantern泵轴承支架pump bearing bracket泵装置pumping device泵装置pumping machine泵组integral pump group泵座pump frame闭式叶轮泵pump with enclosed impellers波纹管泵bellows pump仓底泵bilge pump侧流道泵壳；旋涡泵泵体casing with transfer passages 侧流道泵壳；旋涡泵泵体annular casing长轴深井泵borehole shaft driven(centrifugal) pump 衬青铜泵bronze fitted pump齿轮比例泵abjustable discharge gear pump冲击波泵（振荡器）shock wave oscillator导流壳式多级泵pump with bowl-type vaned casing低温泵cryopump底料泵；塔底液泵bottoms pump底吸泵bottom inlet pump底吸泵bottom suction pump电磁驱动泵pump with cyclic electromagnetic drive 风动活塞泵air-powered piston pump辅泵；辅助泵auxiliary pump辅扫仓泵；副清仓泵auxiliary stripping pump附属泵attached pump工程用泵building site pump固定缸体泵pump with nonrotating cylinder固体输送泵pump for water-borne solids管网泵pump for pipe system灌泵priming of pump锅炉给水泵BFW锅炉给水泵boiler feed pump。
中英文文献翻译-液压泵
附录外文文献原文：The commonly used sources of power in hydraulic systems are pumps and accumulators .Similarly,accumulator connected to atmosphere will dischange oil at atmosphere pressure until it empty. only when connected to a system having resistance to flow can pressure be developed.Three types of pumps find use in fluid-power systems:rotary,reciprocating or piston-type, and 3,centrifugal pumps.Simple hydraulic system may use but one type of pump . The trend is to use pumps with the most satisfactory characteristics for the specific tasks involved . In matching the characteristics of the pump to the requirements of the hydraulic system , it is not unusual to find two types of pumps in series . For example , a centrifugal pump may be to supercharge a reciprocating pump , or a rotary pump may be used to supply pressurized oil for the contronls associated with a reversing variabledisplacement pumps . Most power systems require positive displacement pumps . At high pressure , reciprocating pumps are often preferred to rotary pumps .1、Rotary pumpsThese are built in many differnt designs and extremely popular in modern fluid power system . The most common rotay-pump designs used today are spurgear , internal gear ,generated rotor , sliding vane ,and screew pumps . Ehch type has advantages that make it most suitable for a given application .2、Gear pumpsGear pumps are the simplest type of fixed displacement hydraulic pump available . This type consists of two external gear , generally spur gear , within a closed-fitting housing . One of the gear is driven directly by the pump drive shaft . It ,in turn , then drives the second gear . Some designs utilize helical gears ,but the spur gear design predominates . Gear pumps operate on a very simple principle . As the gear teeth unmesh , the volume at the inlet port A expands , a partial vacuum on the suction side of the pump will be formed . Fluid from an external reservoir or tank is forced by atmospheric pressure into the pumpinlet . The continuous action of the fluid being carried from the inlet to the discharge side one of the pump forces the fluid into the system .3、Vane pumpsThe vane pump consists of a housing that is eccentric or offset with respect to the drive shaft axis . In some models this inside surface consists of a cam ring that can be rotated to shift the relationship between rotor are rectangular and extend radially from a center radius to the outside diameter of the rotor and from end to end . A rectangular vane that is essentially the same size as the slot is inserted in the slot and is free to slide in and out .As the rotor turns , the vanes thrust outward , and the vane tips track the inner surface of the housing , riding on a thin film of fluid . Two port or end plates that engage the end face of the ring provide axial retention .Centrifugal force generally contributes to outward thrust of the vane . As they ride along the eccentric housing surface , the vane move in and out of the rotor slots . The vane divide the area between the rotor and casing into a series of chambers .The sides of each chamber are formed by two adjacent vanes ,the port or end plates , the pump casing and the rotor . These chambers change in change in volume depending on their respective position about the shaft .As each chamber approaches the inlet port , its vanes move outward and its volume expands , causing fluid to flow into the expanded chamber . Fluid is then carried within the chamber around to the dischange port . As the chamber approaches the discharge port , its vanes are pushed inward ,the volume is reduced , and the fluid is forced out the discharge port .Vane pump speed is limited by vane peripheral speed . High peripheral speed will cause cavitation in suction cavity . which results in pump damage and reduced flow .An imbalance of the vanes can cause the oil film between the vane tips and the cam ring to break down , resulting in metal-to-metal contact and subsequent increased wear and slipage . One metheod applied to eliminate high vane thrust loading is a dual-vane construction .4、Piston-type pumpAll piston pumps operate by allowing oil to flow into a pumping cavity as a piston retreats and then forcing the oil out into another chamber as the piston advances . Design differences among pumps lie primarily in the methods of separating inlet from outlet oil .5、In-line piston pumpThe siplest typeof axial piston pump is the swash plate in-line design .The cylinder are connected though piston shoes and a retracting ring , so that the shoes beat anainst an angled swash plate . As the block turns ,the piston shoes follow the swash plate ,causing the piston to reciprocate . The ports are arranged in the valve plate so that the pistons pass the inlet port as they are being pulled out and pass the outlet port as they are being forcing back in .The angle of the swash plate controls the delibery . Where the swash plate is fixed , the pump is of the constant-displacement type . In the variable-displacement , inline piston pump , the swash plate is moumted on a pivoted yoke . As the swash plate angle is increased , the cylinder stroke is increase , resulting in a greater flow . A pressure compensator control can position the yoke automatically to maintain a constant output pressure .6、BENT-axis piston pumpAs the shaft roates , distance between any one piston and the valving surface changes continually . Each piston moves away from the valving surface during one half of the revolution and toward the valving surface during the other half . The inlet chamber is in line as the pistons move away , and the outletr chamber is in line as the pistons move closer , thus drawing liquiring in during one half of the inlet chamber as the pistons are moving away from the pintle . Thereforce , during rotation , pistons draw liquid into the cylinder bores as they pass the inlet side of the pinntle and force that liquid out of the bores as they pass the outlet side of the pintle . The displacement of this pump varies with the offset angle , the maximum angle being 30 degree ,the minimum zero . Fixed displacement models are usually avaiable with 23 degree angle .In the variable displacement construction a yoke with an external control is used to change the angle . With some contronls , the yoke can be moved over center to reverse the direction of flow from the pump .7、Pump/system interactionPressure-compensated variavle delivery pumps do not require a relief valve in the high pressure line . The pressure compensation feature eliminates the need for the relief valve .In nearly all working systems ,however , at least one is used on just-in-case basis . The use of a pressure compensator , while avoiding dependence on a relief valve , brings on its own problems .The actuator -spring-spool arrangement in the compensator is a dynamic , damped-mass-spring arrangement .However , when the system calls for a chang in axhievetheir maxmum volume as they reach the inlet port , the maximum volume of fluid will ve moved .If the relationship between housing and rotor is changed such that the chambers achieve their minimum of zero volume as they reach the inlet port , the pump delivery will be reduced to zero .Vane pump speed is limited by vane peripheral speed . High peripheral speed will cause cavitation in suction cavity , which results in pump damage and reduced flow . An imbalance of the vanes can cause the oil film between the cane tips and the cam ring to break down , resulting in metal-to-metal contact and subsequent increased wear and slipage . One method applied to eliminate high vane thrust loading is a dual-vane construction . In the dual-vane construction , tow independent vanes are located in each totor slot chmbered edges along the sides and top of each vane from a channel that essentially balances the hydraulic pressure on the top and bottom of each pair of vanes .Centrifugal force cause the vane to follow the contour of the cam-shaped ring .There is just sufficient seal between the vanes and ring without destroying the thin oil film .外文文献中文翻译：常用的液压系统的动力源是泵和蓄能器。
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中英文对照资料外文翻译文献附件1：外文资料翻译译文旋转泵旋转泵应用于不同的设计中，在流体动力系统中极其常用。
今天最常用的旋转泵是外齿轮泵、内齿轮泵、摆线转子泵、滑动叶片泵和螺旋泵。
每种类型的泵都有优点，适合于特定场合的应用直齿齿轮泵，这种泵有两个啮合的齿轮在密封壳体内转动。
第一个齿轮即主动轮的回转引起第二个齿轮即从动轮的回转。
驱动轴通常连接到泵上面的齿轮上。
当泵首次启动时，齿轮的旋转迫使空气离开壳体进入排油管。
这种泵内空气运动使泵吸入口处形成了真空，于是外部油箱的液体在大气压的作用下，由泵的入口进入，聚集在上下齿轮和泵壳体之间，齿轮连续的旋转使液体流出泵的出口。
直齿齿轮泵的压力的升高是由挤压啮合齿轮和腔体内的液体产生的。
当齿轮脱开啮合时，腔内形成真空，使更多的液体被吸入泵内。
直齿齿轮泵是定排量的元件，当轴转速不变时，输出流量恒定。
只有一种方法即改变输入轴的转速，能调节这种直齿齿轮泵的排量。
现代应用在流体动力系统的齿轮泵的压力可达3000psi。
图示为直齿齿轮泵的典型特性曲线。
这些曲线表明了泵在不同速度下的流量和输入功率。
当速度给定时，流量曲线接近于一条水平的直线。
泵的流量随出口压力的升高而稍有降低，这是由于泵的出油口到吸油口的齿轮径向泄漏所增加而造成的。
渗漏有时定义为泄漏，泵出口压力的增加也会使泄漏增加。
表征泵的出口压力和流量之间关系曲线常叫做水头流量曲线或泵的HQ曲线；泵的输入功率和泵流量关系曲线叫做功率流量特性曲线或PQ曲线。
直齿齿轮泵的输入功率随输入速度和出口压力的增加而增加。
随着齿轮泵速度的增加，流量（加仑/分）也增加。
于是在出口压力为120psi，转速为200rpm时，输入功率是5马力。
在转速为600rpm时，输入功率是13马力。
纵坐标压力是120psi，横坐标是200rpm和600rpm时，在HQ曲线上可以读出相应的流量分别为40gpm和95gpm。
图示是直齿齿轮泵在粘度不变时的情况。
随着流体粘度的增加（即流体变稠，不易流动），齿轮泵的流量降低。
粘稠的流体在油泵高速运转时，因为这种流体在油泵中不能迅速进入泵体完全充满真空区，所以油流量受到限制。
图示为在流体动力系统中流体粘度的增大对旋转泵工作情况的影响。
当流体的粘度值为100SSU，出口压力为80psi时，泵流量为220gpm。
当流体的粘度值为500SSU时，泵流量减少到150gpm。
由功率特性曲线可知，泵输入功率也会增加可以用齿轮或其他内部元件每转一圈输出多少加仑来表示泵的流量。
如果封闭定量泵的出口，则出口压力将会增加，直至驱动马达停止或泵内其他部分或排油管破裂。
由于存在着破裂的危险，几乎所有的流体动力系统都安装压力溢流阀。
这种溢流阀可安装在泵内，也可安装在排油管路。
滑动式叶片泵:这些泵有大量的叶片，叶片能在转子的槽内自由的滑进滑出。
当驱动转子时，离心力，弹簧或压力油使叶片伸出槽子，顶在泵壳体的内腔或凸轮环上。
随着转子的旋转，叶片之间的流体经过吸油口时，完成吸油。
流体顺着泵壳体到达排出口。
在排出口，流体被排出，进入排油管。
图示的滑动式叶片泵中的叶片安装在椭圆形的腔内。
当转子开始旋转时，离心力使叶片伸出槽子。
同时叶片又受到其底部腔内压力油的作用力，压力油来源于槽子端部的配流盘。
吸油口通过A和A1口相通，他们位于直径的相对位置。
同样两排油口位于类似的位置。
油口这样配置，使叶片转子保持压力平衡，从而使轴承不受重载影响。
当转子逆时针旋转时，从吸油管出来的流体进入A和A1口，聚集在叶片之间，沿周向流动后，通过B和B1口排出。
这样设计的泵压力可达2500psi。
的泵必须分级才能达到这么大的压力，而现在用一级泵即可达到。
在转子上应用均流均压阀可以达到高压。
转速通常限制在2500rpm这是因为考虑到离心力和凸轮环表面叶片之间的磨损。
图示为泵在转速为1200rpm粘度在100F的条件下的特性曲线。
每个槽内安装两个叶片可以控制其作用于壳体内部和凸轮环上的力。
双叶片会产生更紧的密封，能减少从排油口到吸油口之间的泄漏这种入口和出口相对应的设计也能维持液压平衡。
这些都是定量泵。
不改变转速就不能改变叶片泵的流量，除非油泵采用特殊设计。
图示为滑动式变量叶片泵。
它不用双吸油和排油口。
转子在压力腔内转动，转子形成的偏心量是可调的。
随着偏心的程度或偏心率的变化，流体的流量也随着变化。
图示为转子在旋转180°范围内，产生一真空度以便于油液进入，同时压油区也在180°范围内旋转。
吸油区和压油区的起始段梢有重叠。
图示，在最小的工作压力下可以得到最大的流量。
随着压力的升高，流量按预设的规律减少。
当流量减到最小值，压力增大到最大值。
泵只需要提供补充回路中元件滑动配合间隙中泄漏流体这种变量泵的设计可以保护管路，溢流阀不是必须的。
其他回路中，为阻止局部压力超过正常压力水平，可以用安全阀或溢流阀来控制为了自动控制流量，采用可变弹簧负载调节器。
安装这种调节器，泵的出口压力作用于活塞或定子内表面，压缩的弹簧产生位移。
如果泵的出口压力高于调节器弹簧的设定值时，弹簧被压缩。
这使压力环（定子）移动，减少相对于定子的偏心量，于是，泵的流量减少，得到所需的压力。
这种油泵设计的出口压力在100psi 和2500psi之间。
图示为变量泵补偿器的特性，标出输入功率值，可以准确计算所需的输入功率。
变量泵可以预先设定不同压力值的变化规律。
高低压泵控制既能提供有效的卸荷回路，也能为先导控制回路提供足够压力图示阴影区域为变量泵在背压100psi压力下的闭式回路。
油液以100psi卸荷阀或溢流阀排出，可以维持正常的控制回路压力，这些是消耗的功率。
两级压力控制回路包括：先导液压控制和电磁控制。
图示负号表示电磁铁不带电，先导控制油回油箱。
于是泵排出的控制油的力小于调节器弹簧力，所以得到最小压力。
图示正号为电磁铁带电，控制油的力大于调节器弹簧力。
与简单的溢流阀原理一样，小球和弹簧决定控制力的大小。
这样预先设定最大工作压力。
另一种两级压力控制系统是利用所谓的差动卸荷调节器。
它应用于高低压或双泵回路中。
调节器通过压力传感器自动卸荷大流量泵以达到最小的空载压力设定值。
空载压力指的是由于变量泵控制机构工作所形成的特定压力。
泵的实际空载流量等于系统的泄漏量与控制流量之和。
当泵空载时，即使液压系统在提供加紧或保压作用，也不会需要较大的功率。
调节器是液压操纵的，差动活塞带有双压力控制，当外部控制压力作用于控制卸荷口时，差动活塞允许完全卸荷。
空载压力的最小设定值由调节器主弹簧A控制。
最大压力由溢流阀调节点B控制。
调节器的操作压力由大容积泵提供，从小孔C进入。
为了说明如何使用这种装置，假设回路需要1000psi的最大压力，由一个5-gpm 来提供。
在压力达到500psi时，需要大流量（40gpm），继续上升到1000psi，流量减少。
由流量为40-gpm的带有卸荷调节器的泵组成的双泵系统可满足要求。
我们可以把40-gpm的泵从500psi卸荷压力调整至200psi最小设定压力（或另一需求值），这样5-gpm泵可以使回路达到1000psi或更高压力。
图中为双泵系统控制压力源。
由一个40-gpm的泵提供调节器腔内压力，就可以达到最大设定压力。
弹簧设定力加上调节器的腔内压力共同决定了40-gpm泵的最大压力。
第二个控制源是特殊的回路，它能达到1000psi。
控制油通过小孔D进入调节器作用于卸荷活塞E。
活塞E面积比安全阀中提动阀F的有效面积大15％。
因此卸荷差动力大约为15％。
调节器将在500psi卸荷，会在500psi以下15％或425psi时起作用。
这里所谓的卸荷，指的是40-gpm的泵无输出量。
随着回路中压力从0到500psi的增加，调节器腔内的压力也随着增加，直到溢流阀的设定值时，溢流阀打开，流体流出油箱。
调节器腔内的压力降是最大的叠加值，允许油泵达到卸荷状态。
同时，当系统压力继续增加超过700psi时，导致活塞E最底部的压力比顶部的压力大。
活塞使提升阀F完全打开，溢流提升阀全部开启导致调节器腔内压力进一步下降至零。
流体通过小孔C进入调节器腔，经过溢流提升阀直接回油箱，不增加调节器腔内的压力。
40-gpm的泵卸荷压力可以减小至更低的设定值。
调整卸荷调节器，40-gpm的泵达到卸荷。
随着压力到1000psi，回路的流量减至5gpm。
在1000psi时，5-gpm 泵也达到卸荷设定，于是流量仅仅维持系统压力。
在500psi时，40-gpm的油泵卸荷。
需要600psi的系统压力把40gpm的泵卸荷到最小压力200psi。
600psi的先导控制油通过孔D进入并作用于差动活塞E。
在500psi时，泵流量减少到零。
100psi 的附加压力需要完全打开提升阀，使调节器腔内的压力减小至零。
当回路压力减小时，两个泵以同样的方式来工作。
附件2：外文原文Rotary pumpsThese are built in many different designs and are extremely popular in modern fluid-power system. The most common rotary-pump designs used today are spur-gear, generated-rotary , sliding-vane ,and screw pump ,each type has advantages that make it the most suitable for a given application .Spur-gear pumps. these pumps have two mating gears are turned in a closely fitted casing. Rotation of one gear ,the driver causes the second ,or follower gear, to turn . the driving shaft is usually connected to the upper gear of the pump .When the pump is first started ,rotation of gears forces air out the casing and into the discharge pipe. this removal of air from the pump casing produces a partial vacuum on the pump inlet ,here the fluid is trapped between the teeth of the upper and lower gears and the pump casing .continued rotation of the gears forces the fluid out of the pump discharge .Pressure rise in a spur-gear pump is produced by the squeezing action on the fluid ad it is expelled from between the meshing gear teeth and casing ,.a vacuum is formed in the cavity between the teeth ad unmesh, causing more fluid to be drawn into the pump ,a spur-gear pump is a constant-displacement unit ,its discharge is constant at a given shaft speed. the only way the quantity of fluid discharge by a spur-gear pump of type in figure can be regulated is by varying the shaft speed .modern gear pumps used in fluid-power systems develop pressures up to about 3000psi.Figure shows the typical characteristic curves of a spur-gear rotary pump. These curves show the capacity and power input for a spur-gear pump at various speeds. At any given speed the capacity characteristic is nearly a flat line the slight decrease incapacity with rise in discharge pressure is caused by increased leakage across the gears from the discharge to the suction side of the pump. leakage in gear pumps is sometimes termed slip. Slip also increase with arise pump discharge pressure .the curve showing the relation between pump discharge pressure and pump capacity is often termed the head-capacity or HQ curve .the relation between power input and pump capacity is the power-capacity or PQ curve .Power input to a squr-gear pump increases with both the operating speed and discharge pressure .as the speed of a gear pump is increased. Its discharge rate in gallons per minute also rise . thus the horsepower input at a discharge pressure of 120psi is 5hp at 200rpm and about 13hp at 600rpm.the corresponding capacities at these speed and pressure are 40 and 95gpm respectively, read on the 120psi ordinate where it crosses the 200-and 600-rpm HQ curves .Figure is based on spur-gear handing a fluid of constant viscosity , as the viscosity of the fluid handle increases (i.e. ,the fluid becomes thicker and has more resistance to flow ),the capacity of a gear pump decreases , thick ,viscous fluids may limit pump capacity t higher speeds because the fluid cannot into the casing rapidly enough fill it completely .figure shows the effect lf increased fluid biscosity on the performance of rotary pump in fluid-power system .at 80-psi discharge pressure the pp has a capacity lf 220gpm when handling fluid of 100SSU viscosity lf 500SSU . the power input to the pump also rises ,as shown by the power characteristics.Capacity lf rotary pump is often expressed in gallons per revolution of the gear or other internal element .if the outlet of a positive-displacement rotary pump is completely closed, the discharge pressure will increase to the point where the pump driving motor stalls or some part of the pump casing or discharge pipe ruptures .because this danger of rupture exists systems are filled with a pressure –relief valve. This relief valve may be built as of the pump or it may be mounted in the discharge piping.Sliding-Vane Pumps,These pumps have a number of vanes which are free to slide into or out of slots in the pup rotor . when the rotor is turned by the pump driver , centrifugal force , springs , or pressurized fluid causes the vanes to moveoutward in their slots and bear against the inner bore of the pump casing or against a cam ring . as the rotor revolves , fluid flows in between the vanes when they pass the suction port. This fluid is carried around the pump casing until the discharge port is reached. Here the fluid is forced out of the casing and into the discharge pipe.In the sliding-vane pump in Figure the vanes in an oval-shaped bore. Centrifugal force starts the vanes out of their slots when the rotor begins turning. The vanes are held out by pressure which is bled into the cavities behind the vanes from a distributing ring at the end of the vane slots. Suction is through two ports A and AI, placed diametrically opposite each other. Two discharge ports are similarly placed. This arrangement of ports keeps the rotor in hydraulic balance, reliving the bearing of heavy loads. When the rotor turns counterclockwise, fluid from the suction pipe comes into ports A and AI is trapped between the vanes, and is carried around and discharged through ports B and BI. Pumps of this design are built for pressures up to 2500 psi. earlier models required staging to attain pressures approximating those currently available in one stage. Valving , uses to equalize flow and pressure loads as rotor sets are operated in series to attain high pressures. Speed of rotation is usually limited to less than 2500rpm because of centrifugal forces and subsequent wear at the contact point of vanes against the cam-ring surface..Two vanes may be used in each slot to control the force against the interior of the casing or the cam ring. Dual vanes also provide a tighter seal , reducing the leakage from the discharge side to the suction side of the pump . the opposed inlet and discharge port in this design provide hydraulic balance in the same way as the pump, both these pumps are constant-displacement units.The delivery or capacity of a vane-type pump in gallons per minute cannot be changed without changing the speed of rotation unless a special design is used. Figure shows a variable-capacity sliding-vane pump. It dose not use dual suction and discharge ports. The rotor rums in the pressure-chamber ring, which can be adjusted so that it is off-center to the rotor. As the degree of off-center or eccentricity is changed, a variable volume of fluid is discharged. Figure shows that the vanes create a vacuum so that oil enters through 180 of shaft rotation. Discharge also takes placethrough 180 of rotation. There is a slight overlapping of the beginning of the fluid intake function and the beginning of the fluid discharge.Figure shows how maximum flow is available at minimum working pressure. As the pressure rises, flow diminishes in a predetermined pattern. As the flow decreases to a minimum valve, the pressure increases to the maximum. The pump delivers only that fluid needed to replace clearance floes resulting from the usual slide fit in circuit components.A relief valve is not essential with a variable-displacement-type pump of this design to protect pumping mechanism. Other conditions within the circuit may dictate the use of a safety or relief valve to prevent localized pressure buildup beyond the usual working levels.For automatic control of the discharge , an adjustable spring-loaded governor is used . this governor is arranged so that the pump discharge acts on a piston or inner surface of the ring whose movement is opposed by the spring . if the pump discharge pressure rises above that for which the by governor spring is set , the spring is compressed. This allows the pressure-chamber ring to move and take a position that is less off center with respect to the rotor. The pump theb delivers less fluid, and the pressure is established at the desired level. The discharge pressure for units of this design varies between 100 and 2500psi.The characteristics of a variable-displacement-pump compensator are shown in figure. Horsepower input values also shown so that the power input requirements can be accurately computed. Variable-volume vane pumps are capacity of multiple-pressure levels in a predetermined pattern. Two-pressure pump controls can provide an efficient method of unloading a circuit and still hold sufficient pressure available for pilot circuits.The black area of the graph of figure shows a variable-volume pump maintaining a pressure of 100psi against a closed circuit. Wasted power is the result of pumping oil at 100psi through an unloading or relief valve to maintain a source of positive pilot pressure. Two-pressure –type controls include hydraulic, pilot-operated types and solenoid-controlled, pilot-operated types. The pilot oil obtained from thepump discharge cannot assist the governor spring. Minimum pressure will result. The plus figure shows the solenoid energized so that pilot oil assists compensator spring. The amount of assistance is determined by the small ball and spring, acting as a simple relief valve. This provides the predetermined maximum operating pressure.Another type of two-pressure system employs what is termed a differential unloading governor. It is applied in a high-low or two-pump circuit. The governor automatically, Through pressure sensing, unloads the large volume pump to a minimum deadhead pressure setting. Deadhead pressure refers to a specific pressure level established as resulting action of the variable-displacement-pump control mechanism. The pumping action and the resulting flow at deadhead condition are equal to the leakage in the system and pilot-control flow requirements. No major power movement occurs at this time, even though the hydraulic system may be providing a clamping or holding action while the pump is in deadhead position The governor is basically a hydraulically operated, two-pressure control with a differential piston that allows complete unloading when sufficient external pilot pressure is applied to pilot unload port.The minimum deadhead pressure setting is controlled by the main governor spring A. the maximum pressure is controlled by the relief-valve adjustment B. the operating pressure for the governor is generated by the large-volume pump and enters through orifice C.To use this device let us assume that the circuit require a maximum pressure of 1000psi, which will be supplied by a 5-gpm pump. It also needs a large flow (40gpm) at pressure up to 500psi; it continues to 1000pso at the reduced flow rate. A two-pump system with an unloading governor on the 40-gpm pump at 500psi to a minimum pressure setting of 200psi (or another desired value) , which the 5-gpm pump takes the circuit up to1000psi or more.Note in figure that two sources of pilot pressure are required. One ,the 40-gpm pump, provides pressure within the housing so that maximum pressure setting can be obtained. The setting of the spring, plus the pressure within the governor housing, determines the maximum pressure capacity of the 40-gpm pump. The second pilotsource is the circuit proper, which will go to 1000psi. this pilot line enters the governor through orifice D and acts on the unloading piston E . the area of piston E is 15 percent greater than the effective area of the relief poppet F. the governor will unload at 500psi and be activated at 15percent below 500psi, or 425psi. By unloading, we mean zero flow output of the 40-gpm pump.As pressure in the circuit increases from zero to 500psi, the pressure within the governor housing also increases until the relief-valve setting is reached, at which time the relief valve cracks open, allowing flow to the tank.The pressure drop in the hosing is a maximum additive value, allowing the pump to deadhead. Meanwhile, the system pressure continues to rise above 700psi, resulting in a greater force on the bottom of piston E than on the top. The piston then completely unseats poppet F, which results in a further pressure drop within the governor horsing to zero pressure because of the full-open position of the relief poppet F. flow entering the housing through orifice is directed to the tank pass the relief poppet without increasing the pressure in housing. The deadhead pressure of the 40-gpm pump then decreases to the lower set value. Thus , at the flow rate to the unloading governor ,the 40gpm pump goes to deadhead. The flow rate to the circuit decreases to 5gpm as the pressure to 1000psi, the 5-gpm pump is also at its deadhead setting, thus only holding system pressure.The 4-gpm pump unloads its volume at 500psi. It requires a system pressure of 600psi to unload the 40-gpm pump to its minimum pressure of 200psi. the 600-psi pilot supply enters through orifice D and acts on the differential piston E. The pumps volume is reduced to zero circuit-flow output at 500psi. The additional 100-psi pilot pressure is required to open poppet F completely and allow the pressure within the housing to decrease to zero.As circuit pressure decreases ,both pumps come back into service in a similar pattern.。