A projected portion is provided on an outer wall surface of the vane. The projected portion projects toward the inner wall surface of the circumferential wall in a rotational direction. When the inner wall surface and the outer wall surface are contact with each other at the projected portion, a center point of a force applied to the projected portion is located outside of an contacting area where the bolt is threaded into the circumferential wall in order that the circumferential wall is connected with the side wall by the bolt. The circumferential wall can be bent in the rotational direction by the force. Thereby, even if the vane beats the inner wall surface, the shoe-housing hardly deviates in the rotational direction to restrict the bolt from loosing.