Komatsu 830E-AC Shop Manual page 1030

SYSTEM OPERATION
Normal Operation
1. During truck operation, the lubrication cycle
timer will energize the system at a preset time
interval.
2. The timer provides 24 VDC to energize the
pump solenoid valve (3, Figure 3-3), allowing
hydraulic oil provided by the truck steering
pump circuit to flow to the pump motor and ini-
tiate a pumping cycle.
3. The hydraulic oil pressure from the steering cir-
cuit is reduced to 2241 - 2413 kPa (325 - 350
psi) by the pressure reducing valve (4) before
entering the motor. In addition, the amount of oil
supplied to the pump is limited by the flow con-
trol valve (6). Pump pressure can be read using
the gauge (5) mounted on the manifold.
4. With oil flowing into the hydraulic motor, the
grease pump will operate, pumping grease from
the reservoir to the injectors (13), through a
check valve (10) and to the vent valve (11).
5. During this period, the injectors will meter the
appropriate amount of grease to each lubrica-
tion point.
1. Hydraulic Oil Return
2. Hydraulic Oil Supply
3. Pump Solenoid Valve
4. Pressure Reducing Valve
5. Motor Pressure Gauge
P3-6
FIGURE 3-3. HYDRAULIC SCHEMATIC
6. Flow Control Valve
7. Hydraulic Motor
8. Grease Pump
9. Pressure Switch (N.O.)
10. Check Valve
Automatic Lubrication System
6. When grease pressure reaches pressure switch
(18, Figure 3-2) setting, the switch contacts will
close and energize the relay RB7-K5, removing
power from the hydraulic motor/pump solenoid
and the pump will stop. The relay will remain
energized until grease pressure drops (pres-
sure switch opens again) and the timer turns
off.
7. After the pump solenoid valve is de-energized,
hydraulic pressure in the manifold drops and
the vent valve (11, Figure 3-3) will open, releas-
ing grease pressure in the lines to the injector
banks. When this occurs, the injectors are then
able to recharge for the next lubrication cycle.
8. The system will remain at rest until the lubrica-
tion cycle timer turns on and initiates a new
grease cycle.
9. During the normal lubrication cycle, if grease
pressure fails to reach 13,790 kPa (2000 psi) at
the pressure switch located on the rear axle
housing, an amber indicator light will illuminate
on the overhead panel.
11. Vent Valve
12. Orifice
13. Injector Bank
P03030