A power transmission apparatus in one aspect of the present disclosure comprises at least one gear that transmits an inputted driving force to at least one output part; at least one shaft that supports the at least one gear; a displacement portion configured to be mechanically interlocked with a displacement gear among the at least one gear and displaced in association with the displacement gear; a housing that houses the at least one gear and the at least one shaft; and an abutting portion that is disposed in the housing and configured to restrict a possible displacement range of the displacement portion by abutting the displacement portion. The abutting portion is configured so as not to be displaced along with a rotation of the at least one gear and is disposed in the housing at a location spaced apart from the at least one shaft.