Kubota RTV 900 Workshop Manual page 17

RTV900, WSM
Pedal pressed fully, under light load and assist motor startup to maximum capacity level
Let's suppose that the pedal is fully pressed. The control lever is activated by the pedal to switch the regulator
valve's hydraulic circuit. The servo piston (4) is then actuated to tilt the pump's variable swashplate to maximum (see
the above illustration).
The pump cylinder block (5) is driven by the input shaft (19) to put the oil under high pressure and to feed it at the
highest rate out of the pump port A. The pressure-fed oil flows into the motor's port D along the circuit. The pressure
of the oil from the HST pump now gets high enough to start tilting the assist motor's variable swashplate (8). The oil
is fed to the port F (branch flow) and port G too. As a result, the output shaft (14) is driven by the stationary motor and
assist motor. The output shaft rpm drops in proportion to the tilt of the assist motor's variable swashplate, whereas its
torque increases.
Then the stationary motor's oil and the assist motor's oil drops to a low pressure and return through their respective
ports C and E to the pump port B.
9-M8
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
W1014345
KiSC issued 04, 2006 A