Komatsu Galeo PC138US-8 Shop Manual page 212

SEN02550-01
Operation
Operation of motor
At low speed (the motor swash plate angle is maximized.)
1. 2nd travel speed select solenoid valve
2. Regulator valve
3. Spring
4. Check valve
5. Regulator piston
6. Swash plate
7. Parking brake piston
8. Hydraulic pump
9. Travel control valve
10. Pump merge-divider valve
11. Self pressure reducing valve
12. Brake valve
30
10 Structure, function and maintenance standard
Since 2nd travel speed select solenoid valve
q
(1) is de-energized, the pressurized oil from
self pressure reduction valve (11) is not fed to
port (P).
Regulator valve (2) is pushed down with spring
q
(3) reaction force.
The main pressurized oil, sent from the control
q
valve through check valve (4), is controlled by
regulator valve (2) and used to shuts off the cir-
cuit to regular piston (5).
The pressurized oil in control chamber (C) is
q
drained from port (D) through oil passage (e) of
regulator valve (2).
Swash plate (7) reaches its maximum tilt
q
angle, and the machine travels at low speed
with the maximum motor capacity.
PC138US, USLC-8