ABSTRACT
Hysteresis motors attracted very little attention during the early years of the twentieth century since their ‘practical’ use was much limited in comparison to other contemporary motors; for example, the DC motor and the usual synchronous motor. Teare’s paper in 1940 was a fresh start to develop a detailed theory of hysteresis motor torque, based on the principle of “virtual work”. A valuable part of Teare’s theory is the treatment of motor operation at synchronous speed with particular reference to varying load conditions and the effect of odd space harmonics. The essential parts of a hysteresis motor are a stator carrying a distributed winding in slots, excited to produce a rotating magnetic field, similar to a poly-phase induction motor or a single-phase motor with phase splitting, and a rotor that carries no winding and essentially comprises a permanent-magnet material annulus, fitted on an arbor and a shaft machined from a non-magnetic material such as stainless steel.
