Generac Power Systems GN190H, Руководство по обслуживанию и ремонту

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SECTION 12: LUBRICATION
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GENER
A
C
GENERAL
The engine lubrication system serves to (a) reduce friction
between moving parts, (b) cool the engine and (c) estab-
lish a negative pressure in the crankcase to prevent oil seal
leakage.
Major components include the following:
• Oil pickup assembly.
• Oil pump.
• Crankshaft oil seals.
• Pressure relief valve.
• Breather assembly.
• Crankcase cover.
• Low oil pressure switch.
OIL FLOW
See Figure 12.1. The oil pump draws crankcase oil through
an oil pickup and delivers it to the areas requiring lubrication
as follows:
1. Through a cored channel in the crankcase cover and to the
crankshaft journal at the power take-off (PTO) end of the
crankshaft.
2. Through the hollow camshaft and to the camshaft bear-
ing at the flywheel end.
3. Through a cored passage in the crankcase housing and to
the crankshaft journal at the flywheel end.
4. Through the crankshaft to the crankpin and connecting rod
bearing.
Figure 12.1 — Lubrication System Diagram
OIL PICKUP ASSEMBLY
DESCRIPTION:
The oil pickup assembly consists of a plastic body and an
oil pickup screen. The pickup must be installed with its screen
facing downward toward the crankcase base. The tubular end
of the pickup fits into a bore in the crankcase cover. When
the crankcase cover is installed, a cast protrusion in the
crankcase prevents the pickup from coming out.
Figure 12.2 — Oil Pickup Assembly
INSPECTION:
Clean the pickup in solvent. Inspect the plastic body for
cracks or other damage. Check the screen for damage. Make
sure the hollow pickup tube is clean and free of obstructions.
OIL PUMP
DESCRIPTION:
The oil pump (Figure 12.3) is of the gerotor type. Its inner
rotor rotates on a shaft provided in the camshaft bore of the
crankcase cover. The outer rotor is installed over two drive
pins on the end of the camshaft and is driven by camshaft
rotation.
Figure 12.3 — Oil Pump
CAMSHAFT
OUTER
ROTOR
INNER
ROTOR
TO CRANKCASE
COVER
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3
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