材料工程专业英语---UNIT SEVEN-LESSON ONE.ppt

UNIT SEVEN
HYDRAULIC TRANSMISSION
LESSON ONE INTRODUCTION
For many years a hydraulic system was considered the result of plumbing together a number ponents. 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 bination 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
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
Paralleling the improvement in hydraulic fluids and other materials has been an increase in plexity and sophistication of hydraulic systems. Most early hydraulic systems were no plex 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
Through