Daedong DSC48, Workshop Manual

Page: 85 / 290

Apr. 2007
2
-9
DSC48
417W217A
417W216A
2.2 LUBRICATING SYSTEM
(1) Inlet (3) Inner rotor
(2) Outlet (4) Outer rotor
(1) Piston (9) Rocker arm shaft
(2) Idle gear (10) Rocker arm
(3) Oil pump (11) Push rod
(4) Relief valve (12) Tappet
(5) Oil fi lter 1 (13) Oil switch
(6) Oil fi lter element (14) Camshaft
(7) Bypass valve (15) Crankshaft
(8) Oil pan
2.2.1 FLOW OF LUBRICATING OIL
The lubricating oil is forced to each journal through the oil
passages of the cylinder block, cylinder head and shafts.
The oil, splashed by the crankshaft or thrown off from the
bearings, lubricates other parts such as the push rods (11),
tappets (12), piston pins, and timing gears.
2.2.2 OIL PUMP
The oil pump is a gear type whose rotors have trochoid
lobes. The inner rotor (3) has 4 lobes, while the outer rotor
has 5 lobes. They are eccentrically engaged to each other.
The inner rotor, which is driven by the crankshaft through
the gears, rotates the outer rotor in the same direction,
varying in the space between the lobes. While the rotors
rotate from (A) to (B), the space leading to the inlet port in-
creases, which causes the oil to
fl ow through the inlet port.
When the rotors rotate to (C), the port to which the space
leads changes from the inlet to outlet. At (D), the space
volume decreases and oil is discharged through the outlet
port.