Variable speed a.-c. motor control

• US 3,340,450 A
• Filed: 05/25/1965
• Issued: 09/05/1967
• Est. Priority Date: 05/25/1965
• Status: Expired due to Term

• Current Assignee: Kordik, Kenneth S., Stilley, Herschel H.
• Original Assignee: Kordik, Kenneth S., Stilley, Herschel H.
• Inventors: Stilley, Herschel H., Kordik, Kenneth S.
• Application Number:
  US04/458,626
• Time in Patent Office: 833 Days
• US Class Current: 318/832
• CPC Class Codes: H02P 25/20 for pole-changing

Claims

1. A VARIABLE SPEED A.-C. MOTOR COMPRISING, IN COMBINATION, A FRAME, FIRST AND SECOND STATOR ASSEMBLIES ON SAID FRAME HAVING SUBSTANTIALLY IDENTICAL WINDINGS FOR PRODUCING ROTATING FIELDS, MEANS FOR SWITCHING SAID STATOR WINDINGS TO PRODUCE FIRST AND SECOND PREDETERMINED NUMBERS OF WINDING POLE CONNECTIONS, SAID FIRST POLE CONNECTION BEING ONE-HALF THE NUMBERR OF POLES OF SAID SECOND CONNECTION, A WOUND ROTOR IN SAID FRAME HAVING A SINGLE SET OF WINDINGS IN WHICH VOLTAGES ARE INDUCED BY THE STATOR FIELDS, MEANS FOR SWITCHING SAID ROTOR WINDINGS TO OBTAIN A CORRESPONDING NUMBER OF POLES TO SAID STATORS, AND EACH OF SAID STATORS BEING ROTATABLY MOVABLE IN SAID FRAME BETWEEN A NULL PHASE RELATION IN WHICH THE INDUCED VOLTAGES ARE CANCELLED AND AN ALINED PHASE RELATION IN WHICH THE INDUCED VOLTAGES ARE ADDITIVE FOR PRODUCTION OF MAXIMUM TORQUE.