Patent attributes
A planetary gear device includes: a housing cover disposed at one end portion of a housing in an axis direction, the housing being configured to house a sun gear and a planetary gear inside the housing; and a carrier cover disposed next to the housing cover in the axial direction in the inside, and configured to support a shaft of the planetary gear from one end portion side in the axial direction. Of a pair of opposing parts opposite to each other in the housing cover and the carrier cover, one opposing part includes an opening that opens in the axis direction, and the other opposing part includes a slide cylindrical part protruding toward inside of the opening in a coaxial manner with an axis of the opening, the slide cylindrical part including an outer peripheral surface that slides on an inner peripheral surface of the opening.