Seiko Precision Inc.

Tetsuya Iwamoto

Akihiro Ito

Masato Tanaka

Masami Yamamoto

Shinji Morinaga

The rotational torque of an electromagnetic actuator having a stator and rotor, such as a stepping motor, is increased. The electromagnetic actuator includes a rotor () having multiple magnetic poles (Nr, Nr, Nr, Nr, Nr, Sr, Sr, Sr, Sr, Sr) on a circumferential surface () and a plurality of stators () in an electromagnet form. The stator () has a pair of magnetic poles () facing the circumferential surface () of the rotor (), and an auxiliary yoke () made of a soft magnetic material member extending in a circumferential direction (A) over an angular range (&#x3b3;) larger than a spread angle (&#x3b1;) of the magnetic poles (Nr, Sr) of the rotor () in the circumferential direction (A) is provided between the pair of magnetic poles ().

Growing community of inventors

Chiba, Japan

Tetsuya Iwamoto