Patent ID: 7381145

Claim:
An actuator comprising: a motor ( 61 ) which outputs rotation; a first reducer ( 62 ) which receives the rotation from the motor, and outputs the rotation after reducing; and a second reducer ( 63 ) which receives the rotation from the first reducer, and outputs the rotation after reducing; wherein the first reducer includes a first gear ( 61 a ) rotated by the rotation from the motor, a first spur gear mechanism ( 62 a ) having a second gear ( 62 c ) meshed with the first gear, and a first differential gear mechanism ( 62 d ) further reducing the rotation from the first spur gear mechanism; and the second reducer includes a third gear ( 62 b ) rotated by the rotation from the first reducer, a second spur gear mechanism ( 63 a ) having a fourth gear ( 63 c ) meshed with the third gear, and a second differential gear mechanism ( 63 d ) further reducing the rotation from the second spur gear mechanism; wherein the first gear ( 61 a ) rotated by the rotation from the motor and the third gear ( 62 b ) rotated by the rotation from the first reducer are disposed coaxial to each other.