The oil pump (Fig. 1) is two-section, gear type, has a drive ratio of 1.075 from the crankshaft toe gear, is attached to the lower plane of the crankcase
To ensure a lateral clearance between the teeth of gear 5 of the pump drive and the crankshaft gear, equal to 0.15 ... 0.35 mm, a steel gasket can be installed between the crankcase and the pump.
Cast-iron bodies 8 and 14 of the discharge and radiator sections, together with spacer 11, are tightened with bolts 3 and 16.
The required tightness of the connection is achieved without gaskets by careful processing of the butt planes.
High precision manufacturing of parts and the absence of gaskets make it possible to withstand gaps at the ends of the gear: 0.05-0.124 mm for the injection and 0.045-0.102 mm for the radiator sections, which prevents oil from being transferred from the discharge cavities to the suction ones.
Drive gears 9 and 28 of both sections are mounted on shaft 33, which rotates in bronze bushings pressed into the holes of the housings.
Driven gears 10 and 13, together with bronze bushings pressed into them, rotate on a common axis 12.
Oil is supplied to the bushings of the driven gears through radial drillings in them between the gear teeth.
Oil from the sump through a fixed oil receiver with a strainer enters the suction cavity of the radiator section.
From here, a smaller part of the oil is pumped to the centrifuge, a larger part through the connecting hole A in the spacer enters the suction cavity of the injection section and is fed into the lubrication system by its gears.
In the body 14 of the radiator section of the oil pump there are threaded holes for plugs 21, 26 and 22 of the safety valves and valve 23 of the lubrication system, with the safety valve 17 located in the body of the radiator section, and the safety valve 32 and valve 23 - in the body of the discharge section .
The safety valves of both sections are adjusted to an opening pressure of 850...950 kPa. The valve 23 of the lubrication system begins to open when the oil pressure in the main line is 400 ... 450 kPa.