Chapter 4 Hydraulic Actuators (c)Mechanical efficiencies thus TMo =TMt -ATMo (4-6) Mm1 TMo.IM ATMo TMt TMt (4-7) (3)Flow rate and volumetric efficiency 9M=9Mt+△q (4-8) 6 Homepage List Upwards Downward止 Return Exit
Chapter 4 Hydraulic Actuators 6 （c） Mechanical efficiencies thus (4-6) (4-7) T T T Mo Mt Mo = − Mo Mt Mo M m Mt Mt T T T T T − = = （3）Flow rate and volumetric efficiency q q q M Mt = + (4-8)
Chapter 4 Hydraulic Actuators 7ww-M=9M广A9=I- △q gM 9M 9M (4-9) (4)Delivery and rotating speed n= 9ML9MTMY (4-10) V (5)Working and rated pressures Homepage List Upwards Dowrwards Retun Exit
Chapter 4 Hydraulic Actuators 7 (4-9) （4）Delivery and rotating speed (4-10) （5）Working and rated pressures Mt M MV M M M 1 q q q q q q q − = = = − Mt M MV q q n V V = =
Chapter 4 Hydraulic Actuators 2.classification Motors may be classified based upon their working performances: (1)High-speed hydraulic motors whose rated rotating speed is beyond 500r/min; (2)Low-speed hydraulic motors whose rated rotatingspeed is below 500r/min. High-speed hydraulic motors may be further divided into gear motors,vane motors,axial piston motors,screw motors,etc.Low-speed hydraulic motors include single-acting connectingrod type radial piston motors and incurve multiple-acting radial piston motors. Motors can also be classified as fixed delivery and variable delivery according to their delivery types. The graphic symbols of motor is shown in Fig.4-1. b Fig.4-1 Graphics symbols of motor a)Fixed delivery motor b)Variable delivery motor 8 Homepage List Upwards Downward止s Retumn Exit
Chapter 4 Hydraulic Actuators 8 2. classification Motors may be classified based upon their working performances: (1) High-speed hydraulic motors whose rated rotating speed is beyond 500r/min; (2) Low-speed hydraulic motors whose rated rotating speed is below 500r/min. High-speed hydraulic motors may be further divided into gear motors, vane motors, axial piston motors, screw motors, etc. Low-speed hydraulic motors include single-acting connecting rod type radial piston motors and incurve multiple-acting radial piston motors. Motors can also be classified as fixed delivery and variable delivery according to their delivery types. Fig.4-1 Graphics symbols of motor a) Fixed delivery motor b) Variable delivery motor The graphic symbols of motor is shown in Fig.4-1
Chapter 4 Hydraulic Actuators 4.1.2 Operating principle of hydraulic motors 1.Axial piston motors B—B A一 Pressurized oil Returned oi Fig.4-2 Operating principle of axial piston motors 1-Swashplate 2-Cylinder 3-piston 4-Control lens 5-Shaft Homepage List Upwards Dowrwards Return Exit
Chapter 4 Hydraulic Actuators 9 4.1.2 Operating principle of hydraulic motors 1. Axial piston motors Fig. 4-2 Operating principle of axial piston motors 1-Swashplate 2-Cylinder 3-piston 4-Control lens 5-Shaft
Chapter 4 Hydraulic Actuators 2.Vane motors Double-acting vane motors are generally used in industrial hydraulic systems,here a double-acting design operation is illustrated as follows: Fig.4-3 Operating principle of balanced vane motor Pla D吧 1,2,3,4,5,6,7,8-Vanes 10 Homepage List Upwards Downward止 Retumn Exit
Chapter 4 Hydraulic Actuators 10 2. Vane motors Double-acting vane motors are generally used in industrial hydraulic systems, here a double-acting design operation is illustrated as follows: Fig.4-3 Operating principle of balanced vane motor 1, 2 , 3 , 4 , 5 , 6 , 7 , 8－Vanes