SPECIAL SQUIRREL-CAGE TYPE INDUCTION MOTOR

PURPOSE:To reduce the surging of torque and occurrence of noise, by performing multiple grooving directly to the circumferential surface of a rotor core or to a rotor conductor such as thin copper plate wound around the circumferential surface of the rotor core. CONSTITUTION:A special squirrel-cage type induction motor is equipped with a rotor 1 and a stator 6. The rotor 1 is equipped with a rotor conductor 4, such as thin copper plate, wound around the circumferential surface of a rotor core 3 fitted to a shaft 2. In order to obtain effective torque current without eddy currents due to the secondary current, multiple grooves 5A and 5B are formed to the surface of this conductor 4. Thus, the surging of torque in superlow speed operation can be reduced on a wide scale.