Patent ID: 7866287

Claim:
A pump system for supplying pressurized hydraulic fluid to a hydraulic valve actuation system for operating engine valves of an internal combustion engine, comprising: a pump driven by the internal combustion engine, the pump operable to receive hydraulic fluid from a reservoir and to pressurize the fluid and supply the pressurized fluid to the hydraulic valve actuation system during rotation of the engine; and a booster pump driven by a drive member of the internal combustion engine via a decoupler which is operable to couple the booster pump with the drive member when the engine is rotating below a pre-selected speed and to decouple the booster pump from the drive member to stop operation of the booster pump when the engine is rotating above the pre-selected speed, the booster pump being operable to receive hydraulic fluid from the reservoir and to pressurize the fluid and supply the pressurized fluid to the hydraulic valve actuation system during start up of the engine.