液壓與氣壓傳動外文翻譯(存儲版)

　　

【正文】 n addition, they can change the direction of drive as easily as they can vary the speed. As in many other types of machine, many plex mechanical linkages can be simplified or even wholly eliminated by the use of hydraulics. The flexibility and resilience of hydraulic power is another great virtue of this form of drive. Apart from the smoothness of operation thus obtained, a great improvement is usually found in the surface finish on the work and the tool can make heavier cuts without detriment and will last considerably longer without regrinding. Hydraulic and Pneumatic system Hydraulic System There are only three basic methods of transmitting power: electrical, mechanical, and fluid power. Most applications actually use a bination of the three methods to obtain the most efficient overall system. To properly determine which principle method to use, it is important to know the salient features of each type. For example, fluid systems can transmit power more economically over greater distances than can mechanical types. However, fluid systems are restricted to shorter distances than are electrical systems. Hydraulic power transmission system are concerned with the generation, modelation, and control of pressure and flow， and in general such systems include: which convert available power from the prime mover to hydraulic power at the actuator. which control the direction of pumpflow, the level of power produced, and the amount of fluidflow to the actuators. The power level is determined by controlling both the flow and pressure level. which convert hydtaulic power to usable mechanical power output at the point required. medium, which is a liquid, provides rigid transmission and control as well as lubrication of ponts, sealing in valves, and cooling of the system. which link the various system ponents, provide power conductors for the fluid under pressure, and fluid flow return to tank(reservoir). storage and conditioning equipment which ensure sufficient quality and quantity as well as cooling of the fluid. Hydraulic systems are used in industrial applications such as stamping presses, steel mills, and general manufacturing, agricultural machines, mining industry, aviation, space technology, deepsea exploration, transportion, marine technology, and offshore gas and petroleum exploration. In short, very few people get through a day of their lives without somehow benefiting from the technology of hydraulicks. The secret of hydraulic system’s success and widespread use is its versatility and manageability. Fluid power is not hindered by the geometry of the machine as is the case in mechanical systems. Also, power can be transmitted in almost limitless quantities because fluid systems are not so limited by the physical limitations of materials as are the electrical systems. For example, the performance of an electromang is limited by the saturation limit of steel. On the other hand, the power limit of fluid systems is limited only by the strength capacity of the material. Industry is going to depend more and more on automation in order to increase productivity. This includes remote and direct control of production operations, manufacturing processes, and materials handling. Fluid power is the muscle of automation because of advantages in the following four major categories. and accuracy of control. By the use of simple levers and push buttons, the operator of a fluid po