US Patent 7395791 Valve timing controller with a stopper

A valve timing controller is disclosed that includes first and second rotating elements, and a phase changing mechanism including arm members coupling the first and second rotating elements. The valve timing controller also includes a cam plate and a stopper to restrict rotation of the cam plate. A concave part where the stopper and the cam plate contact. Also, a damper chamber is defined between the concave part and one of the stopper and the cam plate.