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 a two-dimensional plane. In the case of small size, the SIM has large thrust compared with a linear induction motor (LIM) because the slots in the SIM can be used effectively. For 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 the circumference of the 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%.