Rotary actuator

A rotary actuator configured to rotate a shaft of a subject device, comprising:

• a housing;
• an electric motor that is received in the housing;
• an output axle that has an axle hole, through which the shaft is inserted while the shaft is fitted to the axle hole, wherein the output axle is configured to be rotated by a torque outputted from the electric motor and output the torque to the shaft;
• a magnet holder that has a holder hole, into which the shaft is fitted, wherein the magnet holder is configured to be rotated integrally with the shaft;
• a magnet that is placed at the magnet holder and is configured to generate a magnetic flux;
• and
• an angle sensor that is configured to sense the magnetic flux generated from the magnet and output a signal, which corresponds to a rotational angle of the magnet holder, wherein:
• the output axle includes:
• an axle pipe portion, at which the axle hole is formed;
• and
• an output axle tubular portion, which is located on a side of the axle pipe portion that is opposite to the subject device;
• and
• the magnet holder includes:
• a holder main body, at which the holder hole is formed;
• and
• a seal portion, which is formed integrally with the holder main body in one-piece, while the seal portion is configured to contact one of an inner peripheral wall and an outer peripheral wall of the output axle tubular portion and seal between the magnet holder and the output axle tubular portion.