Patent number: 7194992

Hydraulic cushioning of a variable valve timing mechanism

Original Assignee: BorgWarner Inc.

Field of technology: Vehicles, Engines and Transportation

Patent granted on: Tue, 27 Mar 2007

Patent drawing

Abstract

A phaser comprising a housing, a rotor, and first and second passages. The housing has at least one chamber defined by an advance wall, an arcuate outer wall, and a retard wall. The rotor has at least one vane projecting from an outer circumference, separating the chamber in the housing into advance and retard chambers. The first passage facilitates fluid communication to a first port in the advance or retard chamber and a second passage to a second port in the other advance or retard chambers. Each port is spaced apart form the first wall or second wall of the vane, such that when the vane is moved towards the advance or retard wall of the chamber far enough, the passages are obstructed by the housing and fluid flow to the passages is restricted, such that impact of the vane with the walls of the chamber is cushioned.