The design of the oil pump is shown in fig. 4.13.
Oil pump type «Duocentic» with trochoidal gearing, driven by the crankshaft through a chain drive, is installed in the engine sump and takes oil from the sump with an oil receiver, after which it pumps it through a full-flow oil filter into the pressure oil line of the engine. The oil filter is installed separately from the engine and connected to it with hoses, connected in series with the main line.
After the oil filter, a pressure reducing valve is installed, which, when the pressure rises above the set value, dumps excess oil into the oil bath (pallet). When the filter is clogged, the bypass valve directs the unfiltered oil directly into the pressure line. The opening pressure of the reducing valve is 4.5 kgf/cm2.
A non-return valve is installed in the oil filter fitting, which prevents oil from flowing out of the channels and valve lifters after the engine is stopped.
The purified oil flows through the pressure line and its branches to the main bearings of the crankshaft. Through inclined drillings in the body of the crankshaft, oil enters the connecting rod journals and sprays to the piston pins and cylinder mirrors. At the same time, engine oil through vertical channels enters the cylinder head to the camshaft bearings, cylindrical valve lifters, valve guides, chain tensioners and the mechanism for changing the position of the intake valve drive shaft.