An oil passage portion forms a part of an oil supply passage inside. A check valve part includes a valve seat portion press-fitted into the oil passage portion. The check valve part allows flow of hydraulic oil from a hydraulic oil supply source to a hydraulic chamber, and restricts flow of the hydraulic oil from the hydraulic chamber to the hydraulic oil supply source. A filter is provided downstream of the valve seat portion in the oil supply passage so as to collect a foreign matter in the oil supply passage.