Motor with redundant windings

• US 4,434,389 A
• Filed: 10/28/1980
• Issued: 02/28/1984
• Est. Priority Date: 10/28/1980
• Status: Expired due to Term

• Current Assignee: Kollmorgen Technologies Corporation
• Original Assignee: Kollmorgen Technologies Corporation
• Inventors: Langley, Lawrence W., Bross, Roger B.
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): BERGMANN, SAUL
• Application Number:
  US06/201,478
• Time in Patent Office: 1,218 Days
• Field of Search: 310/112, 310/126, 310/134, 310/141-144, 310/146, 310/149, 310/150, 310/254, 310/46, 310/166, 310/179, 310/184, 310/216, 318/138, 318/254, 318/639, 318/701
• US Class Current: 318/400.41
• CPC Class Codes: H02K 11/33 Drive circuits, e.g. power electronics H02K11/38 takes precedence
• CPC Class Codes: H02K 16/04 Machines with one rotor and two stators
• CPC Class Codes: H02K 29/08 using magnetic effect devices, e.g. Hall-plates, magneto-resistors H02K29/12 takes precedence
• CPC Class Codes: H02K 3/28 Layout of windings or of connections between windings windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32

Abstract

An electric motor is wound with redundant sets of windings which are energized by independent electric circuits to enable operation of the motor even in the presence of a failure of a winding and a failure of an energization circuit. The motor may be of the permanent magnet form with electronic switching of the winding currents in lieu of switching via a commutator, known as a brushless DC motor, in which case separate sensing devices, such as Hall effect devices, are employed with each winding set and energization circuit for sensing the relative position between the moving and stationary members of the motor. The sets of windings, when placed on the stator, are physically spaced apart so as to minimize magnetic coupling therebetween.

Claims

1. A DC electric servomotor comprising:

a pair of relatively movable members, one being the stator and the other being the rotor of said electric servomotor;

said stator including at least two sets of distributed, non-overlapping redundant windings spaced apart for minimal magnetic coupling therebetween, each of said windings being independently excitable to produce a reversible magnetic field for rotating said rotor in either direction;

said redundant winding being mounted on said stator such that torque summing is achieved from the torques generated by the individual ones of said redundant windings; and

a separate commutation circuit for each set of redundant windings, said commutation circuits each being connected to a different one of said sets of redundant windings to produce the moving magnetic field from a DC power source for causing rotation of said rotor.

2. A servomotor according to claim 1 wherein said rotor includes permanent magnets for producing a field cooperating with said moving magnetic field for causing synchronous motor rotation.

3. A servomotor according to claim 1 wherein said commutation circuits each include a position sensor to indicate the relative position between said rotor and said stator and solid state switching circuits for controlling energization of the associated set of redundant windings in accordance with the rotor position.