Abstract

A method of providing hydraulic pressure for mechanical work from an engine lubricating system in an internal combustion engine by supplying oil to an engine lubrication gallery for lubricating the engine and at least one variable oil demand accessory. Each of the variable oil demand accessories have individual pressure regulators. The output of the variable displacement pump is regulated to the sum of fluid flow required by the engine lubricating system and the demand for fluid generated by the individual pressure regulators on each of the engine accessories, regardless of the engine output.