Positioning of a cover relative to a housing is made at two locations. i.e., fitting between a first intermediate shaft and a first recess and fitting between a second intermediate shaft and a second recess. In this way, a load of the cover is not conducted to an output shaft through a cover-side bearing. Therefore, in a state where the cover is fixed to the housing, an excessively large load is not generated between a cover-side bearing and the output shaft and a housing-side bearing and the output shaft.