Generac Power Systems GTH1000, Руководство по обслуживанию

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OIL COOLER
All GTH/GTV-760/990 V-Twin engines are equipped with an oil cooler,
which is mounted on the blower housing. Forced air from the flywheel
fan flows through the oil cooler fins dissipating heat from the engine
oil (see Figure 8-5) .
The oil cooler fins should be cleaned every 100 hours (or more often
under dusty conditions) and checked periodically for debris. Clean
with compressed air or a soft bristle brush.
Figure 8-5. Oil Cooler
OIL PUMP
All Generac engines utilize a gerotor style oil pump which is classified
as a positive displacement pump. Every revolution of the pump will
displace a constant amount of oil. As the inner rotor turns, oil is drawn
into the oil intake and fills the entire cavity between the inner and the
outer rotor. As the gerotor continues to rotate, oil is moved from the
intake port to the outlet port where the oil is pushed under pressure
throughout the entire lubrication system (see Figure 8-6).
PRESSURE RELIEF VALVES
When a constant displacement pump is used, a relief valve is neces-
sary to relieve the build-up of pressure in the system. Relief valves
are needed because the pump supplies more pressurized oil than the
system is able to use.
Generac uses two relief valves; a "Cold Start" and a "Common" valve.
When the oil is cold and the engine is started, the oil pressure can
reach up to 140 psi. To avoid damage to the oil filter and oil cooler, the
"Cold Start" relief valve is installed in series immediately downstream
of the oil pump and is set at 60 psi. After the oil goes through the oil
cooler and filter, it flows through the "Common" relief valve. This relief
valve is set at 40 psi and mainly regulates the pressure to the PTO
journal and throughout the rest of the oil system (Figure 8-7 and 8-8).
CAMSHAFT
PUMP COVER
PUMP BODY
PICK-UP
SCREEN
OUTER ROTOR
INNER ROTOR
Figure 8-6. Oil Pump, Vertical Engine
PICK-UP SCREEN
COLD START
RELIEF VALVE
(60 psi)
COMMON
RELIEF VALVE
(40 psi)
Figure 8-7. Oil Pump, Horizontal Engine
SECTION 8: LUBRICATION SYSTEM
8-3
8