Kubota RTV 900 Workshop Manual page 14

RTV900, WSM
Neutral
The oil that is drawn by the charge pump (18) from the transmission case (13) flows through the oil cooler (20), oil
filter cartridge (21) and charge relief valve (15) into the HST hydraulic circuit and regulator valve. Surplus flow is
returned from the charge relief valve to the HST housing and finally into the transmission case.
When the panel is released (neutral position), the regulator spool (3) is also at the neutral position. The pump's
variable swash plate (17) is interlocked with the servo piston (4), is will not tilt.
In this way, the HST pump keeps rotating but the pump piston is stationary as no oil is being fed from the HST
pump. Until oil is fed back from the HST pump, the cylinder assembly of the stationary motor and assist motor are
halted which keeps the output shaft from turning.
9-M5
NEW TRANSMISSION
(1) Pedal
(2) Regulator Valve Assembly
(3) Regulator Spool
(4) Servo Piston
(5) Cylinder Block
(6) HST Housing
(7) Control Piston
(8) Variable Swashplate
(Assist Motor)
(9) Cylinder Block (Assist Motor)
(10) Cylinder Block
(Stationary Motor)
(11) Check and High Pressure
Relief Valve
(12) Bypass Valve
(13) Transmission Case
(14) Output Shaft
(15) Charge Relief Valve
(16) Oil Filter Cartridge (Suction)
(17) Variable Swashplate
(HST Pump)
(18) Charge Pump
(19) Input Shaft
(20) Oil Cooler
(21) Oil Filter Cartridge
a : To HST Housing
b : Connects with Cable for
VHT Pressure Release
Knob
c : Connects with Brake Cam
Lever
W1013477
KiSC issued 04, 2006 A