Patent number: 8820280

Variable camshaft timing mechanism with a default mode

Original Assignee: BorgWarner Inc.

Field of technology: Vehicles, Engines and Transportation

Patent granted on: Tue, 02 Sep 2014

Patent drawing

Abstract

A variable cam timing phaser with a control valve for directing fluid from a fluid input to and from the advance chamber and the retard chamber of the phaser through an advance line, a retard line, a common line, an advance default line, a retard default line, and at least one exhaust line. The control valve being movable between a default mode and an oil pressure actuated mode. In the default mode, the control valve blocks exhaust lines, retaining fluid within the chambers. The oil pressure actuated mode includes at least an advance mode, a retard mode, and a holding position.