SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING Paralleling the improvement in hydraulic fluids and other materials has been an increase in the complexity and sophistication sophistication of hydraulic systems. Most early hydraulic改进,复杂化 systems were no more complex than the pump 泵 system in an automobile hydraulic jack. The Jack contains a hand operated pump which draw(a) draws oil from a reservoir. Oil is pumped past reservoir iH fA a check or non-return valve into a linear check valve单向阀 actuator. The oil flowing into the actuator piston活塞 forces the piston to move. The moving piston can do work on an outside load. a valve controls flow from the piston back to the reservoirSCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING Paralleling the improvement in hydraulic fluids and other materials has been an increase in the complexity and sophistication of hydraulic systems. Most early hydraulic systems were no more complex than the system in an automobile hydraulic jack. The jack contains a hand operated pump which draws oil from a reservoir. Oil is pumped past a check or non-return valve into a linear actuator. The oil flowing into the actuator forces the piston to move. The moving piston can do work on an outside load. A valve controls flow from the piston back to the reservoir. sophistication 改进，复杂化 pump 泵 draw 吸（入） reservoir 油箱 check valve 单向阀 piston 活塞