An oil supply system for an engine

摘要

An oil supply system for a reciprocating piston internal combustion engine is disclosed in which the supply of oil to piston cooling jets is controlled by pressure operated valves designed to open at a pre-defined valve opening pressure. The pressure of oil supplied by a pump is controlled to be below this pre-defined valve opening pressure during operation of the engine in which piston cooling is not required, and the pressure of oil is controlled to above the pre-defined valve opening pressure when piston cooling is required. The control of the pump is by an electronic control unit based upon a combination of engine speed and engine load.