A rotary apparatus includes a motor including a rotary shaft, a plurality of gears including an output gear, and a housing accommodating the motor and the plurality of gears. The housing is separable into a first housing and a second housing. The motor includes a first end portion and a second end portion located on an opposite side of the first end portion. The rotary shaft is derived from the first end portion. The second housing includes a first regulating portion regulating a position of a part of the motor on the first end portion. The first housing includes a projecting portion projecting toward the second housing side. The projecting portion urges the second end portion of the motor toward the first regulating portion side directly or via another member.