ROTOR OF INDUCTION MOTOR

PROBLEM TO BE SOLVED: To provide the rotor of an induction motor which enables forming a cage-type coil winding easily and positively regardless of the use of a copper material and hence suppressing a secondary resistance loss fully, and obtaining an induction motor with a high torque and a high efficiency easily. SOLUTION: A cage-type coil winding forming body 7A, where a rod-shaped member 7Aa that becomes a conductor bar for constituting the cage-shaped coil winding of a rotor and a ring-shaped member 7Ab that becomes one end ring for comprising the cage-type coil winding of the rotor are formed in one piece by performing the cold extrusion of a copper material, is used and is combined to a rotor core made of a lamination electromagnetic steel plate, and a ring-shaped member 7c that becomes the other end ring is mounted as the rotor of a cage-type coil winding type induction motor. Since the cage-type coil winding forming body 7A is used, a cage-type coil winding made of a copper material can be created easily. Also, since copper with a smaller proper resistance than aluminum by approximately 40% is used, temperature increase can be prevented by that amount, thus improving the efficiency of the electric motor. Further, since a secondary resistance can be reduced, the maximum output and the maximum torque can be improved, thus reducing sliding positively.