机械专业英语论文1

Application and development of mechanical dynamics

Beginning of the 21st century, the development of dexterous manipulator, walking robots, machine tool, removable optical instrument platform, train, automobile active chassis as the representative of the intelligent electronic products will be one goal of China's machinery industry. Such mechanical and electrical products with innovative materials, structural lightweight, mobile, intelligent and high, resulting in a material nonlinearity, complex geometric nonlinear dynamics, nonlinear control with lag. These issues will be studied mechanical dynamics in the field of frontier in the early 21st century.

First the contents of the mechanical dynamics：

Any mechanical, while in the presence of motion, will be subject to the force. In the study Machinery and mechanical force generated by the movement in motion when the mechanical dynamics, and mechanical design and improvement of science from the perspective of the interaction force and movement. Detailed mechanical dynamics research can be divided into the following six:

（1）At a known external force, required to have identified the true movement of the inertial parameters of the mechanical system; analysis of interaction between the various components of the mechanical motion; research institutions and balance theory and method of the rotary member; mechanical vibration analysis; and institutional analysis and synthesis, and so on.

（2）Analysis of the interaction between the various components of the mechanical movement. Size and variation of the structural design of these forces is deputy campaign, the carrying capacity of supporting and component analysis and the choice of a reasonable basis for lubrication method. After obtaining the mechanical movement of the real force of inertia can be calculated for each member, and then based on Alembert principle determined by statics interaction between components. researching the institutional balance and the revolving member of theories and

methods.For rigid rotor balancing existing mature technologies and methods: both the theory and methods need further research to work flexible rotor speed approaches or exceeds the balance of the natural frequency of the rotor itself.

（3）Relationship between balance and distribution of mechanical energy during operation. These include: mechanical efficiency calculations and analysis; theory and design governor; flywheel applications and design.

Analysis of mechanical vibration is one of the basic elements of mechanical dynamics. It has developed into a content-rich, self-contained discipline.

（4）Organizations and agencies comprehensive analysis of the general structure and motion mechanism is concerned, but with the improvement of the mechanical speed of operation, mechanical dynamics analysis and synthesis of high-speed has become an indispensable element when institutions.

Second the mechanical dynamics of classification：

Mechanical dynamics analysis process, according to their different functions can be divided into two types of problems:

(1) Dynamics inverse problem: Given the state of motion and resistance mechanism (moment), the solution should be applied to the counterweight (balanced torque) on the driving member, and a variety of anti-vice campaign force, which is known campaign, seeking power.

(2) The positive dynamics of the problem: Given the machine's input force (torque) and the resistance variation, the time to solve the movement of the machine, which is a known force, seeking movement.

Third, the mechanical dynamics in modern mechanical systems

From the analysis, simulation to design and control, mechanical dynamics in the study area continues to expand, the formation of a number of branches, such as: machine tool dynamics, vehicle dynamics, rotor dynamics, robot dynamics, elastic body dynamics and soon on.

(1) Machine Dynamics

For precision machine tools, the machining accuracy is important as an indicator, and the machine vibration is seriously undermined the machining accuracy. Complex

excitation force generated during cutting, gear transmission system, such as rolling bearings is the internal vibration source machine. Research machine dynamics are: the machine power source analysis, dynamic modeling and vibration machine vibration analysis and dynamic design of the machine.

(2) Vehicle Dynamics

With high speed, safety and comfort of the vehicle becomes very important. And there were many unique dynamics, such as: Vibration wheels on the rails with a taper will lead serpentine movement of the train, it will stimulate the lateral movement of the vehicle; high-speed train on the rate of movement of the curve in the region when the major issues involved in vehicle safety; to improve the comfort of the car, when the latest research trends active vibration control of the frame, and the movement that inspire every moment according to the road, ready to adjust the parameters of the vibration system components, it is always in optimum damping condition.

(3) Rotor dynamics

Steam turbines, generators, motors, centrifuges and other rotating machinery, the main rotor of their work. In order to improve the efficiency and capacity of the machine, increasing the speed of such mechanical. Suppress the vibration of the rotor system when key issues. Especially for large turbine generator rotor damage due to vibration caused by the national economy will result in significant losses. 1980s, China's two 200,000 ten million Turbine claiming the minor axis vibration caused serious incidents. Rotor dynamics and vibration of the rotor support system and countermeasures. It vibration of the shaft and the shaft early as the basis, but the operating speed turbine generator shaft exceeds the critical speed, but also contains a more complex and more vibration, thus forming an important branch of mechanical dynamics.

(4) Robot dynamics

1960s, robotics born and developed rapidly, it is the body, mechanical electronics, computer science and information science from a multidisciplinary frontier. A variety of industrial robots has become increasingly widely used in paint, handling, welding and assembly of industrial production line, all kinds of special robots are used in

marine exploration, outer space exploration and other fields. Robots learn to become a branch of the agency agency science hyperactive. In order to improve the speed of the robot, high-speed, flexible robot has emerged. The complexity of the robot mechanism far more than the general planar mechanisms, and must consider the dynamics of the robot control.

Machine dynamics, vehicle, rotor and robots, which focuses on this type of machinery personality problems. The various types of machinery are included with institutions of various types of machinery and systems are a prime mover, transmission and composition of the working machine. Therefore, institutional dynamics and dynamics of mechanical systems in a variety of mechanical dynamics of the common problems.

Fourth mechanical dynamics of the Future

A mechanical development of modern significant feature is that automatic adjustment and control devices are increasingly becoming an integral part of the machinery. Mechanical dynamics of the study has been extended to include the different characteristics of the power machine and control and regulation devices, including the entire mechanical systems, control theory has infiltrated into the field of mechanical dynamics.

In some mechanical design, mechanical dynamics of change has made quality. Various simulation methods and testing theories and methods of movement and dynamic parameters, is increasingly becoming an important means of mechanical dynamics studies.