wsm L503 Workshop Manual page 205

L3130 · L3430 · L3830 · L4630 · L5030, WSM
Forward
(1) Transmission Case
(2) Filter
(3) Input Shaft
(4) Charge Pump
(5) Pump Cylinder
(6) Variable Swashplate
(7) Regulator Valve Assembly
(8) Servo Piston
When the HST pedal (10) is stepped on and in forward, so the variable swashplate (6) is tilted by the servo piston
(8) and regulator valve (11) as shown in figure above.
As the pump cylinder block (5) rotates with the input shaft (3), oil is forced out of pump port A at high pressure. As
pressure oil enters motor port D, the pistons, which align with port D, are pushed against the thrust plate and slide
down inclined surface.
Then the output shaft (21) rotates with the motor cylinder block (20). This drives the machine forward and the angle
of pump swashplate determines the output shaft speed.
As the motor cylinder block continues to rotate, oil is forced out of motor port C at low pressure and returns to the
pump port B.
(9) Feedback Lever
(10) HST Pedal
(11) Regulator Valve
(12) Bypass Pipe
(13) HST Assembly
(14) Main Circuit and Steering
Circuit
(15) Oil Cooler
(16) Filter
(17) Case Relief Valve
(18) Charge Relief Valve
(19) PTO Clutch Valve Circuit
(20) Motor Cylinder
(21) Output Shaft
(22) Check and High Pressure
Relief Valve
3-M31
TRANSMISSION
A : Pump Port A
B : Pump Port B
C : Motor Port C
D : Motor Port D
KiSC issued 02, 2007 A