Electric motor having a low short-circuit torque, drive device with a plurality of motors and method for producing such a motor

Patent metadata

Field	Value
Publication number	US-10243417-B2
Application number	US-201414782159-A
Country	US
Kind code	B2
Filing date	Apr 2, 2014
Priority date	Apr 5, 2013
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A magnet motor has a stator formed from a laminated core provided with windings to form phases and a rotor provided with magnets distributed angularly around at least one section of the rotor and pivotably received in the housing of the stator. The stator has a length greater than a length of said section of the rotor and the rotor is provided with at least one ring made from magnetic material that adjoins said section and is received in the housing of the stator. A drive device having a plurality of motors and a method for producing such a motor are also provided.

First claim

The invention claimed is:

1. A magnet motor, comprising
a stator formed from a bundle of sheets provided with coils to form phases; and
a rotor provided with magnets distributed angularly around at least a portion of the rotor and received pivotally in a housing of the stator,
wherein the stator has a length greater than a length of said portion of the rotor,
wherein the rotor is provided with at least one ring made of magnetic material, which adjoins said portion and is received in the housing of the stator, the at least one ring not being a magnet and making it possible to have a low short-circuit torque, and an air-gap between the ring and the stator being substantially identical to the minimal air-gap between the magnets and the stator, and
wherein a non-magnetic space is disposed in the longitudinal direction between the at least one ring and the magnets, the non-magnetic space being larger than an air gap between the magnets and the stator.

2. The motor as claimed in claim 1 , wherein the ring has a smooth outer surface.

3. The motor as claimed in claim 1 , wherein the ring has a toothed outer surface.

4. The motor as claimed in claim 1 , wherein the rotor comprises two portions provided with magnets, and the ring is mounted between the two portions.

5. The motor as claimed in claim 4 , wherein a second ring made of magnetic material is mounted at an end of one of the portions.

6. The motor as claimed in claim 1 , wherein the ring is made of iron or a magnetic alloy.

7. The motor as claimed in claim 1 , wherein the ring is formed in two coaxial annular parts, the two coaxial annular parts including an outer coaxial annular part made of magnetic material and an inner coaxial annular part in contact with the rotor and made of non-magnetic material, the inner coaxial annular part having a thickness greater than an air-gap between the magnets and the stator.

8. A drive device comprising at least two motors, of which at least one is formed in accordance with claim 1 , the rotors of the motors being connected to the same element to be moved.

9. The device as claimed in claim 8 , wherein the rotors of the motors are connected to the same shaft.

10. A method for producing a motor as claimed in claim 1 , comprising the steps of producing the stator, mounting the magnets on the rotor, and mounting a ring made of magnetic material on the rotor, the stator and the ring having a length selected on the basis of a desired inductance of the motor, and the ring having an outer surface selected on the basis of a desired reluctance of the motor.

Assignees

• Sagem Defense Securite
• Safran Electronics & Defense

Inventors

• Piaton Jerome

Classifications

• H02K21/02

  Details · CPC title

• H02K2213/12

  Machines characterised by the modularity of some components · CPC title

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title

• H02K21/14

  with magnets rotating within the armatures · CPC title

• H02K16/02

  Machines with one stator and two {or more} rotors · CPC title