New form of unlaminated rotor motor

This paper reports on a new form of unlaminated rotor induction motor which has the characteristics of solid rotor motor at starting but with very much improved running performance. The motor has a hollow and unlaminated rotor. The outer surface of the rotor is left plain while the inner surface is fitted with cage winding. The motor employs two conventional polyphase stators. High starting torque to inertia ratio, high torque per unit volume and the ability to operate at three different speeds are some of the salient features of the motor. The motor performance is demonstrated experimentally.