An object is to reduce manufacturing cost of a housing, and enable to disuse an adhesive in fixation portions between a housing and a bearing sleeve and the like.A housing 7 is made of resin material, which comprises a liquid crystal polymer (LCP) as crystalline resin blended with carbon nanotubes in a blending ratio of 2 to 35 vol % as a conductive filler, by injection molding. A bearing sleeve 8, which is inserted into the inner peripheral surface 7c of the housing 7, is secured to the housing 7 by ultrasonic welding.