新版轮机英语unit25 Anchor windlass and

The efficient working of the anchor windlass is essential to the safety of the ship .
An anchor windlass can expect to fulfill（满足） the following:
1.The windlass cable lifter brakes must be able to control the running anchor and cable when the cable lifter is disconnected from the gear during “letting go”（放锚）.
The construction of a mooring winch will now be examined, again with respect to Fig.25-2.
The motor drive is passed through a spur gear transmission （直齿轮传动机构）, a clutch and thus to the drum（卷筒） and warp end.
This is generally obtained by using a
high ratio worm gear（涡轮）
followed by a single step of spur
gears（单级正齿轮） between the warpend shaft and cablelifters.
On larger mooring winches where a barrel brake is fitted, it is now common practice to design the brake to withstand the breaking strength of the mooring wire.
A spur gear（正齿轮） assembly transmits the motor drive to shaft where the various dog clutches enable the power take-off .
Separate band brakes（独立式刹 车） are fitted hold the cable lifter and the mooring drum（绞缆筒） when the power is switched off.
The most conventional types of equipment in use are as follows.
Windlasses
This equipment is self-contained （独立的）and normally one prime mover drives two cablelifters and two warp ends （绞缆端）,
Details of the snugs（卡块） used to grip the cable and band brake（带式刹车） can be seen.
Anchor capstans（起锚绞盘） are used in some installations where the cable lifter rotates
Each of these units maybe separately engaged（啮合） or disengaged by means or a dog clutch（牙嵌离合器） ,although the
warp end is often driven in
association with the mooring drum.
This “full load” duty of the windlass varies but is commonly between 4 and 6 times the weight of one anchor ,the speed of haul being at least 9 m/min up to 15 m/min.
A more recent development , particularly on large vessels, is the split windlass where one machine is used for each
anchor.
Hale Waihona Puke One unit of a split windlass(分 离式锚机） is shown in Fig.251.
Alternatively, multi steps of spur
gears are used.
Capstans（起锚机） with this type of equipment the driving machinery is situated below deck and the cablelifters are mounted horizontally being driven by vertical shafts.
Winches with various arrangements of barrels are the usual mooring equipment used on board ships .
A mooring winch is Fig.25-2 where the various parts can be identified.
Lesson 25 Anchor windlass and Mooring winch
锚机和绞缆机
Anchor handling equipment
The windlass（锚机） is the usual anchor handling device where one machine may be used to handle both anchor .
The winch barrel or drum is used for hauling（收紧） in or letting out the wires or ropes which will fasten the ship to the shore.
The warp end is used when moving the ship using ropes or wires fastened to bollards（系缆 桩） ashore and wrap around the warpend of tile winch.
thereafter the load is held（握持） by the prime mover brake or barrel brake when the power is shut off.
The winch cannot pay out wire unless the brake is overhauled （超越） or recover wire unless manually operated, thus wires may become slack.
about a vertical axis.
Only the cable lifter unit is located on deck ,the driving machinery （驱动机械） being on the deck
below .
A warping end or barrel may be driven by the same unit and is positioned near the cable lifter.
Mooring winches
Mooring winches provide the facility for tensioning the wire up to the stalling capacity（堵转转矩） of the winch（绞车）, usually 1.5 times full load（全负荷）,
Due to the low speed of rotation required of the cablelifter whilst heaving anchor,
(345r/min) a high gear reduction (齿轮减速机构） is needed when the windlass is driven by a high speed electric of hydraulic motor.
the latter may not be declutchable （离合装置） and ,if so, rotate when the cablelifters are engaged.
There is some variation in detail design of cable lifters and in their drives.
The cable lifter unit（锚链轮） , show in Fig.25-1, is mounted so as to raise and lower the cable from the spurling pipe（锚链管） ,which is at the top and center of the chain or cable locker（锚链舱） .
Average cable speeds vary between 5-7 m/sec during this operation
2.The windlass must be able heave a certain weight of cable at a specified speed（额 定转速） .
The rotating units consist of a cable lifter(锚链轮） with shaped smug（凸起） to grip the anchor cable（锚链）,