wsm RTV-X1120D Workshop Manual page 235

RTV-X900, RTV-X1120D, WSM
[E] Horse-power Control When The Speed Control Pedal Is Pressed While Overloaded
The diagram shows the motion of the regulator valve spool (17) when the speed control pedal (21) is pressed all
the way down.
The servo piston (16) tilts the variable swashplate (19) on the pump side to the maximum position.
The pump block is driven by the input shaft (10) and high pressure oil is discharged from port A.
High pressure oil that is discharged from port A of the pump flows along the circuit to port C on the motor side.
Based on pressure of oil discharged from the pump, the control piston 1 (2) tilts the cylinder block variable
swashplate (5) on the motor to the maximum position.
Here, the piston volume on the motor is maximized.
When a heavier load is applied, the variable swashplate (19) on the pump side moves to neutral.
When the swashplate returns to neutral, the load on the engine is lightened.
When the load on the engine is lightened, engine speed rises again.
The discharge flow from the pump is reduced at the same time but engine speed recovers before the set pressure
of the high pressure relief valve (24) is reached.
Here, maximum output torque is reached.
2-M20
TRANSMISSION
(1) Unload Valve
(2) Control Piston 1
(3) Control Piston 2
(4) HST Housing
(5) Variable Swashplate
(Motor)
(6) Output Shaft
(7) Cylinder Block
(Stationary Motor)
(8) Control Piston 3
(9) Anti-cavitation Valve
(10) Input Shaft
(11) Charge Relief Valve
(12) Oil Filter
(13) Charge Pump
(14) Oil Filter Cartridge (Suction)
(15) Oil Tank
(16) Servo Piston
(17) Regulator Valve Spool
(18) Regulator Valve
(19) Variable Swashplate
(HST Pump)
(20) Cylinder Block
(21) Speed Control Pedal
(22) Check Valve
(23) Orifice
(24) Check And High Pressure
Relief Valve (Forward)
(25) High Pressure Relief Valve
(Dynamic Brake)
a: To HST Housing
A: A Port
B: B Port
C: C Port
D: D Port
9Y1210946TRM0022US0
KiSC issued 01, 2014 A