液压与气压传动的特点及发展应用概况

液压与气压传动的特点及发展应用概况(中文1900,英文1100字)
1.    液压传动有以下优点
1）在同等体积下，液压装置毕电气装置产生更高的动力。再同等功率下，液压装置体积小，重量轻，功率密度大，结构紧凑。液压马达的体积和重量只有同等功率电动机的12%左右。
2）液压装置工作比较平稳。由于重量轻、惯性小、反应快，液压装置易于实现快速启动、制动和频繁的换向。
3）液压装置能在大范围内实现无级调速（调速范围可达2000），它还可以在运行过程中进行调速。
4）液压传动易于自动化，它对液体压力、流量或流动方向易于进行调节或控制。当将液压控制和电气控制、电子控制或气动控制结合起来使用时，整个传动装置能实现复杂的顺序动作，也能方便的实现远程控制。

The Features and Development History and Application of Hydraulic and Pneumatic Transmission
1. The advantages of hydraulic transmission
1) A hydraulic system can produce higher power than electrical equipment under the same volume. The hydraulic equipment system has smaller volume, light, high power consistency and compact configuration at a given power. The volume and weight of a hydraulic motor are about 12% of an electric motor.
2) Hydraulic equipment has a good working stability. It is because of light , less inertia , quick response : the hydraulic equipment can realize celerity start-up , brake and frequent change in motion direction .