Electric machine having at least one magnetic field detector

• US 6,683,397 B2
• Filed: 04/08/2002
• Issued: 01/27/2004
• Est. Priority Date: 04/17/2001
• Status: Expired due to Fees

• Current Assignee: Moteurs Leroy Somer (Emerson Electric Company)
• Original Assignee: Moteurs Leroy Somer (Emerson Electric Company)
• Inventors: Saint-Michel, Jacques, Coupart, Eric, Gilles, Christophe, Gauthier, Pascal
• Primary Examiner(s): Lam, Thanh
• Application Number:
  US10/117,031
• Publication Number:
  US 20020149275A1
• Time in Patent Office: 659 Days
• Field of Search: 310/68.B, 310/156.01, 310/156.02, 310/156.05, 310/156.06, 310/156.07, 310/156.48, 310/156.49, 310/208, 310/254
• US Class Current: 310/68.00B
• CPC Class Codes: H02K 29/08 using magnetic effect devices, e.g. Hall-plates, magneto-resistors H02K29/12 takes precedence
• CPC Class Codes: H02K 3/18 Windings for salient poles

Abstract

An electric machine includes a stator and a permanent magnet flux-concentrating rotor. The permanent magnet flux-concentrating rotor has permanent magnets and pole pieces. The permanent magnets are engaged between the pole pieces. The electric machine also has at least one magnetic-field detector that is mounted on the stator. The at least one-magnetic-field detector is mounted on the stator in such a manner as to detect a magnetic field of the permanent magnets in a location that overlaps a peripheral region of the rotor when the machine if observed on the axis of rotation of the rotor.

Claims

1. An electric machine, comprising:

a stator;

a permanent magnet flux-concentrating rotor having permanent magnets and non-magnet pole pieces, the permanent magnets being engaged between pole pieces; and

at least one magnetic-field detector mounted on the stator in such a manner as to detect a magnetic field of the permanent magnets in a location that overlaps a peripheral region of the rotor when the machine is observed along a direction that is parallel to the axis of rotation of said rotor.

2. A machine according to claim 1, wherein power supply to said motor is polyphase electricity having n phases, and wherein said motor includes n detectors fixed on teeth of the stator.

3. A machine according to claim 2, wherein said teeth are consecutive teeth.

4. A machine according to claim 3, wherein said machine has a case and said detectors are grouped together facing an opening in said case.

5. A machine according to claim 1, wherein the stator has a magnetic circuit and said detectors are fixed on one axial end of said magnetic circuit of the stator.

6. A machine according to claim 1, wherein each detector extends along a radial axis of a tooth.

7. A machine according to claim 1, wherein each detector includes a Hall effect sensor.

8. A machine according to claim 1, wherein each tooth of said stator receives an individual coil.

9. A machine according to claim 8, wherein said individual coil comprises a bundle of insulated wires, the bundle being substantially flat and wound around a winding axis in such a manner as to form a plurality of superposed turns, said bundle having a cross-section in the superposed turns which has a long dimension that extends substantially perpendicularly to said winding axis of the coil.

10. A machine according to claim 8, wherein the individual coil co-operates with the tooth to leave a gap which receives at least one of said detector and electrical conductors connected to said detector.

11. A machine according to claim 1, wherein the rotor includes at least one cheek-plate made of a non-magnetic material, said cheek-plate having an outside radial edge extending slightly set-back from the outside radial edges of the magnets and of the pole pieces in such a manner as to provide an annular region in which said magnetic field can be detected by said at least one magnetic field detector.

12. A machine according to claim 1, wherein the stator does not have pole swellings.

13. A machine according to claim 1, wherein the detector comprises a temperature sensor.