Pump System for Supplying Pressurized Hydraulic Fluid to a Hydraulically Activated Valvetrain

摘要

A pump system for supplying pressurized hydraulic fluid to a hydraulic valve actuation system for operating engine valves of an internal combustion engine comprises a conventional pump, driven by the engine, which supplies the necessary volume of pressurized hydraulic fluid when the engine is running. The system further comprises a booster pump which is driven by the starter motor of the engine and which supplies the necessary volume of hydraulic fluid during starting/cranking of the engine. The conventional pump is preferably designed and constructed for operating efficiency during engine operating conditions while the booster pump is preferably designed and constructed for operating efficiency during cranking/starting of the engine.