Chapter I Introduction to Hydraulic and Pneumatic Transmission From the mentioned above,we can see that a hydraulic system can be divided into five logical segments: (1)Power input segment (energy )to transfer the mechanical energy to hydraulic power.It usually consists of one or several pumps.(as such No.1.pump on the Fig.1-2) (2)Power output segment (actuator):to transfer the hydraulic power to the mechanical energy.(such as actuator 4 on the Fig.1-2) (3)Control components:it can be used in a hydraulic system to restrict the pressure,regulate the speed of actuator or the motion direction; (such as No.6,No2.,and No.3.on the Fig.1-2) (4)Assistant components it can be used to keep system working. (such as No.7,and No.8.on the Fig.1-2) (g5) Homepage List Upwards Downwards Retun ExitChapter 1 Introduction to Hydraulic and Pneumatic Transmission 8 From the mentioned above, we can see that a hydraulic system can be divided into five logical segments: （1）Power input segment (energy ): to transfer the mechanical energy to hydraulic power. It usually consists of one or several pumps. (as such No.1.pump on the Fig.1-2) （2）Power output segment (actuator): to transfer the hydraulic power to the mechanical energy. (such as actuator 4 on the Fig.1-2) （3） Control components: it can be used in a hydraulic system to restrict the pressure, regulate the speed of actuator or the motion direction; (such as No.6, No2., and No.3. on the Fig.1-2) （4） Assistant components : it can be used to keep system working. (such as No.7, and No.8. on the Fig.1-2) （5）Working oil: hydraulic oil (medium)