Direct-current electric motor and use thereof as a drive of a liftgate

Patent metadata

Field	Value
Publication number	US-12451783-B2
Application number	US-202118035335-A
Country	US
Kind code	B2
Filing date	Nov 11, 2021
Priority date	Nov 13, 2020
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A DC electric motor for driving a tailgate of a vehicle is provided, the DC electric motor including a rotor and a stator, the rotor being rotatably supported about an axis of rotation, at least one of the rotor and the stator having a magnetic asymmetry for generating an asymmetric magnetic interaction between the rotor and the stator, wherein the rotor and the stator are configured to assume first positions and second positions relative to each other, wherein a higher holding torque acts between the rotor and the stator in one of the first positions than in one of the second positions due to the asymmetry.

First claim

The invention claimed is:

1. A use of a DC electric motor as a drive for driving a tailgate of a vehicle, the DC electric motor comprising a rotor and a stator, the rotor being mounted for rotation relative to the stator about an axis of rotation,
wherein the rotor comprises a magnetic asymmetry means for generating an asymmetric magnetic interaction between the rotor and the stator,
wherein the rotor and the stator are configured to assume first positions and second positions relative to each other, wherein a higher holding torque acts between the rotor and the stator in one of the first positions than in one of the second positions due to the magnetic asymmetry means,
wherein the rotor comprises a plurality of rotor poles,
wherein the rotor comprises a plurality of pole pieces extending from each of the plurality of rotor poles on one side or on two sides in a direction of rotation of the rotor, and
wherein the magnetic asymmetry means is embodied by at least one of the plurality of pole pieces being shaped asymmetrically to an axis of symmetry of the rotor pole carrying the at least one pole piece,
the DC electric motor and the magnetic asymmetry means being designed in such a way that the holding torque of the DC electric motor is greater than or equal to the torque which the tailgate generates by its own weight on the drive.

2. The use of the DC electric motor according to claim 1 ,
wherein the magnetic asymmetry means comprises a one-sided shortening of the at least one pole piece.

3. The use of the DC electric motor according to claim 1 , wherein the holding torque of the DC electric motor is greater than or equal to the torque which the tailgate generates by its own weight on the rotor.

4. A use of a DC electric motor as a drive for driving a tailgate of a vehicle, the DC electric motor comprising:
a rotor and a stator, the rotor being mounted for rotation relative to the stator about an axis of rotation,
wherein the rotor comprises a magnetic asymmetry means for generating an asymmetric magnetic interaction between the rotor and the stator,
wherein the rotor and the stator are adapted to assume first positions and second positions relative to each other, wherein a higher holding torque acts between the rotor and the stator in one of the first positions than in one of the second positions due to the asymmetry means,
wherein the rotor comprises a plurality of rotor poles,
wherein the rotor comprises a plurality of pole pieces extending from each of the plurality of rotor poles on one side or on two sides in a direction of rotation of the rotor, and
wherein the magnetic asymmetry means is embodied by at least one of the plurality of pole pieces comprising a different material than the other pole pieces,
the DC electric motor and the magnetic asymmetry means being designed in such a way that the holding torque of the DC electric motor is greater than or equal to the torque which the tailgate generates by its own weight on the drive.

5. The use of the DC electric motor according to claim 4 , wherein the holding torque of the DC electric motor is greater than or equal to the torque which the tailgate generates by its own weight on the rotor.

6. A use of a DC electric motor as a drive for driving a tailgate of a vehicle, the DC electric motor comprising:
a rotor and a stator, the rotor being mounted for rotation relative to the stator about an axis of rotation,
wherein the rotor comprises a magnetic asymmetry means for generating an asymmetric magnetic interaction between the rotor and the stator,
wherein the rotor and the stator are adapted to assume first positions and second positions relative to each other, wherein a higher holding torque acts between the rotor and the stator in one of the first positions than in one of the second positions due to the asymmetry means,
wherein the rotor comprises a plurality of rotor poles,
wherein the rotor comprises a plurality of pole pieces extending from each of the plurality of rotor poles on one side or on two sides in a direction of rotation of the rotor, and
wherein the magnetic asymmetry means is embodied by at least one of the plurality of pole pieces having holes or cavities that affect the magnetic properties of the at least one of the plurality of pole pieces,
the DC electric motor and the magnetic asymmetry means being designed in such a way that the holding torque of the DC electric motor is greater than or equal to the torque which the tailgate generates by its own weight on the drive.

7. The use of the DC electric motor according to claim 6 , wherein the holding torque of the DC electric motor is greater than or equal to the torque which the tailgate generates by its own weight on the rotor.

Assignees

• Stabilus Gmbh

Inventors

• Höfer Florian
• Bochen Marian
• Knopp Axel

Classifications

• H02K26/00

  Machines adapted to function as torque motors, i.e. to exert a torque when stalled · CPC title

• H02K23/42

  having split poles, i.e. zones for varying reluctance by gaps in poles or by poles with different spacing of the air gap · CPC title

• H02K23/40 Primary

  characterised by the arrangement of the magnet circuits · CPC title

• H02K2201/03

  Machines characterised by aspects of the air-gap between rotor and stator · CPC title

• H02K23/405

  Machines with a special form of the pole shoes · CPC title