Patent number: 6935290

Avoid drawing air into VCT chamber by exhausting oil into an oil ring

Original Assignee: BorgWarner Inc.

Field of technology: Vehicles, Engines and Transportation

Patent granted on: Tue, 30 Aug 2005

Patent drawing

Abstract

A VCT phaser for an internal combustion engine with at least one camshaft comprising a housing, a rotor, a spool valve and a ring-shaped reservoir. The housing having at least one chamber and the rotor having at least one vane dividing the chambers into advance and retard. The spool valve is comprised of a spool mounted within a bore of the rotor. The reservoir is defined within the bore by an oil dam and at least one of the spool lands. The spool has a first position in which a chamber is coupled to the supply and the other chamber is exhausting fluid and a second position in which a chamber is coupled to the supply and the other chamber is coupled to the reservoir. When a torque reversal occurs, hydraulic fluid pooled in the reservoir is drawn into the other chamber when the spool is in the second position.