Rotary actuator

A rotary actuator for a shift-by-wire system of a vehicle, the rotary actuator comprising:

• a motor;
• an output shaft arranged parallel to a rotation shaft of the motor;
• and
• a deceleration mechanism that reduces a rotational speed of the motor and transmits rotation of the motor at a reduced rotational speed to the output shaft, wherein
• the deceleration mechanism includes a drive gear provided over an axis of the rotation shaft and a driven gear provided over an axis of the output shaft to mesh with the drive gear,
• the driven gear is a separate member from the output shaft,
• the driven gear has an annular portion fitted to the output shaft and a gear plate portion protruding radially outward from the annular portion,
• the output shaft has an external tooth portion, at a location between one end and the other end of the output shaft,
• the annular portion includes an internal tooth portion to engage with the external tooth portion,
• the driven gear is rotatable relative to the output shaft by an amount of play between the internal tooth portion and the external tooth portion in a rotational direction,
• the gear plate portion has a meshing portion meshing with the drive gear,
• positions of the meshing portion and the internal tooth portion of the annular portion fitted with the output shaft overlap each other in an axial direction,
• the one end of the output shaft is rotatably supported by a first flanged bush,
• the other end of the output shaft is rotatably supported by a second flanged bush, and
• the driven gear is supported by being interposed between a first flange portion of the first flanged bush and a second flange portion of the second flanged bush in an axial direction.