SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING UNIT SEVEN HYDRAULIC TRANSMISSION hydraulic液力的 LESSON ONE INTRODUCTION transmission传动 For many years a hydraulic system was plumbing considered the result of plumbing together a 管件总称 number of components. Also, a hydrauliccomponent system has been considered merely the source组成部分 of power for control servos. Each of these servo faHE concepts can lead to basic errors. Following伺服系统 either of these guide lines can result in inadequate systems, which are inadequate, unstable, or a 不充足的 combination of the two unstable不稳定的
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING UNIT SEVEN HYDRAULIC TRANSMISSION LESSON ONE INTRODUCTION For many years a hydraulic system was considered the result of plumbing together a number of components. Also, a hydraulic system has been considered merely the source of power for control servos. Each of these concepts can lead to basic errors. Following either of these guide lines can result in systems, which are inadequate, unstable, or a combination of the two. hydraulic 液力的 transmission 传动 plumbing 管件总称 component 组成部分 servo 伺服 伺服系统 inadequate 不充足的 unstable 不稳定的
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING From an operational standpoint, any hydraulic system can be divided into four accumulator 蓄能器 logical segments: The power input segment, the tube connector power transmission system, the control devices管接头 and the power output portion. The power input swivel joint gment usuall! consists of pumps and转节,旋转接头 accumulators. The power transmission system flexible hose th includes tubing, tubing connectors, swivel joints and flexible hose. Flow control valves, relief valve 溢流阀 pressure control val ves. And relief valves make oscillatory up the control elements. The power output摆动的,振荡的 portion usually consists of rotary and actuator oscillatory motor or linear actuators. Because al most all practical hydraulic systems can be 执行机构 divided into these same four basic segments they will be considered in detail later
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING From an operational standpoint, any hydraulic system can be divided into four logical segments: The power input segment, the power transmission system, the control devices and the power output portion. The power input segment usually consists of pumps and accumulators. The power transmission system includes tubing, tubing connectors, swivel joints and flexible hose. Flow control valves, pressure control valves. And relief valves make up the control elements. The power output portion usually consists of rotary and oscillatory motor or linear actuators. Because almost all practical hydraulic systems can be divided into these same four basic segments, they will be considered in detail later. accumulator 蓄能器 tube connector 管接头 swivel joint 转节，旋转接头 flexible hose 软管 relief valve 溢流阀 oscillatory 摆动的，振荡的 actuator 执行机构
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 reservoir
SCIENCE 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
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 motor
SCIENCE 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
SCIENCE AND TECHNOLOGY ENGLIAH FOR MECHANICAL ENGINEERING ADVANTAGES OF HYDRAULIC SYSTEMS What are the reasons for using hydraulic power in heavy-duty industrial, mobile and aircraft designs? Even though pneumatic control systems preceded hydraulic servos, and electrical power is in more widespread use than hydraulic, systems which require high power amplification or which must pack great energy into a small space are almost invariably hydraulic If hydraulic power transmission and amplification were to be compared with pneumatic, electrical and mechanical systems. these are some of the reasons for specifying hydraulic power mplification放大,加强 invariably不变的
SCIENCE AND TECHNOLOGY ENGLISH FOR MECHANICAL ENGINEERING ADVANTAGES OF HYDRAULIC SYSTEMS What are the reasons for using hydraulic power in heavy-duty industrial, mobile and aircraft designs? Even though pneumatic control systems preceded hydraulic servos, and electrical power is in more widespread use than hydraulic, systems which require high power amplification or which must pack great energy into a small space are almost invariably hydraulic. If hydraulic power transmission and amplification were to be compared with pneumatic, electrical and mechanical systems, these are some of the reasons for specifying hydraulic power. amplification 放大，加强 invariably 不变的