SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING Through the use of power driven pumps and directional control valves these simple systems have grown so that a sequentially number of loads can be handled相继的,结果的 independently or sequentially from the sameamplifier放大器 power source. Power hydraulics is a power amplifier in which a small effort applied to boost促进 a control device results in a large amount of refinement work performed on a load. With boost I精确,精心安装 servos, hydraulic power aids the operator's irreversible effort. Further refinement has led to the不可逆的 irreversible servo-mechanism in which the operators effort is separated from the load by the rigidity of the oil in the actuating cylinder or motorSCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING Through the use of power driven pumps and directional control valves these simple systems have grown so that a number of loads can be handled independently or sequentially from the same power source. Power hydraulics is a power amplifier in which a small effort applied to a control device results in a large amount of work performed on a load. With boost servos, hydraulic power aids the operator’s effort. Further refinement has led to the irreversible servo-mechanism in which the operator’s effort is separated from the load by the rigidity of the oil in the actuating cylinder or motor. sequentially 相继的，结果的 amplifier 放大器 boost 促进 refinement 精确，精心安装 irreversible 不可逆的