Oil pump ZIL-131

The oil pump (Fig. 1) is a two-section gear pump.

The upper section of the oil pump supplies oil to the engine lubrication system and to the centrifuge, and the lower section to the oil radiator.

The pressure reducing valve 3, built into the oil pump cover, is adjusted to a pressure of 3.2 kg/cm 2 (not less) and transfers oil from the pressure cavity of the oil pump to the suction cavity.

Oil pump: 1 - lower section housing; 2 - bypass valve; 3 - pressure-reducing valve; 4 - centering sleeve; 5 - oil pump shaft; 6 - upper section housing; 7 - upper section drive gear; 8 - spring ring; 9 - pin; 10 - lower section drive gear; 11 - lower section driven gear; 12 - gaskets; 13 - oil pump cover; 14 - driven gear of the upper section

The minimum permissible oil pressure in the engine, warmed up to operating temperature, should be 0.5 kg/cm 2 at idle (500 rpm) and 1.5 kg/cm 2 at a crankshaft speed of 1200 rpm.

The lower section of the oil pump supplies oil to the oil radiator.

The bypass valve built into the housing of the lower section of the oil pump is adjusted to a pressure of 1.2 kg/cm 2.