Two-dimensional drive characteristics by circular shaped motor

An induction type motor with a toroidal core called a surface induction motor (SIM) is proposed for any directional motion in the two-dimensional plane. In the case of small size motors, the SIM has large thrust compared with the linear induction motor (LIM) because the slots in SIM can be used effectively. For a practical use, a conventional double-layer winding and ordinary three-phase inverters are used. However, the winding is divided into four or eight sections in the direction of circumference of core. The eight-division type SIM supplied by four inverters can change the direction of linear motion continuously with constant thrust by increasing the main winding current by only about 11%.