US Patent 7556000 Camshaft phaser having designated contact vane

In a vane-type camshaft phaser, one vane extends over a much larger internal angle than the other two vanes. Because of its size and strength, the large vane is the vane designated for contact with the stator. The other vanes and lobes have extra clearance to prevent contact regardless of rotor position. In one embodiment, a first surface of the large vane engages a surface of a first adjacent lobe at one extreme rotor rotation, and a second surface of the large vane engages a surface of a second adjacent lobe at the opposite extreme of rotation. The contact surfaces of the lobes and the vane may be equipped with hardened wear pads. One or more wear pads may be machined to provide a desired rotor displacement angle.