Torque sensor

Patent metadata

Field	Value
Publication number	US-9574958-B2
Application number	US-201314134613-A
Country	US
Kind code	B2
Filing date	Dec 19, 2013
Priority date	Dec 20, 2012
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

An embodiment discloses a sensor arrangement comprising disc shaped structure with a plurality of magnetic elements which are at least provided on end faces of the disc shaped structure. The sensor arrangement includes a hollow disc structure, the hollow disc structure comprising two end faces, wherein each of the two end faces of the second structure comprises a plurality of teeth spaced apart from each other, the teeth on the two end faces are arranged in opposing positions. Teeth on a respective same end face of the hollow disc structure are spaced from each other. The disc shaped structure is rotatable with respect to the hollow disc structure. A magnetic field sensor is provided to sense a magnetic field generated by the plurality magnetic elements.

First claim

What is claimed is:

1. A sensor arrangement, comprising:
a disc shaped structure, wherein a plurality of magnetic elements are at least provided on end faces of the disc shaped structure;
a hollow disc structure, the hollow disc structure comprising two end faces, wherein each of the two end faces of the hollow disc structure comprises a plurality of teeth spaced apart from each other, wherein teeth on the two end faces are arranged in opposing positions, and wherein teeth which are provided on a respective same end face are spaced from each other; the disc shaped structure being rotatable with respect to the hollow disc structure; and
a magnetic field sensor to sense a magnetic field generated by the magnetic elements,
wherein the disc shaped structure is connected to a first shaft and the hollow disc structure is connected to a second shaft, the sensor arrangement being configured to determine an applied torque based on a relative rotation between the disc shaped structure and the hollow disc structure.

2. The sensor arrangement according to claim 1 , wherein the plurality of teeth are distributed on a circumference centered on the center of the hollow disc structure and wherein the plurality of magnetic elements are distributed on a circumference centered on a center of the disc shaped structure.

3. The sensor arrangement according to claim 2 , wherein each of the plurality of teeth extends in a direction towards the center.

4. The sensor arrangement according to claim 3 , wherein each of the plurality of teeth tapers in a direction towards the center of the hollow disc structure.

5. The sensor arrangement according to claim 1 , wherein the magnetic elements are arranged in the disc shaped structure such that the direction of a magnetic moment of each magnetic element is orthogonal to end surfaces of the disk shaped structure.

6. The sensor arrangement according to claim 1 , wherein the hollow disc structure is connected to the second shaft coaxially to the first shaft, and the plurality of magnetic elements are arranged such that for each magnetic element a direction of magnetic moment is parallel to an axis of the first shaft and an axis of the second shaft.

7. The sensor arrangement according to claim 1 , wherein the disc shaped structure comprises a plurality of holes, the plurality of holes extending from one of the two end faces of the disc shaped structure to the other of the two end faces of the disc shaped structure, wherein the plurality of magnetic elements is arranged in the plurality of holes.

8. The sensor arrangement according to claim 6 , wherein the plurality of magnetic elements is arranged in an alternative polarity manner wherein adjacent magnetic elements have opposite magnetic polarities.

9. The sensor arrangement according to claim 1 , further comprising a pair of magnetic conductive circular ring sheets, the pair of magnetic conductive circular ring sheets at least partially surrounding the hollow disc structure.

10. The sensor arrangement according to claim 9 , wherein the pair of magnetic conductive circular ring sheets comprises an installation block for installing the magnetic field sensor such that magnetic flux is guided to the magnetic field sensor.

11. The sensor arrangement according to claim 10 , wherein the magnetic field sensor is provided between a first installation block of a first one of the pair of magnetic conductive circular rings and a second installation block of a second one of the pair of magnetic conductive circular rings.

12. The sensor arrangement according to claim 7 , wherein the plurality of holes is a plurality of circular through holes, and wherein the plurality of magnetic elements comprises a cylindrical structure, each of the plurality of magnetic elements having its two end faces flush with the two end faces of the disc.

13. The sensor arrangement according to claim 1 , wherein the two end faces of the hollow disc structure are formed by opposing ring sheets of magnetic conductive material, and wherein the plurality of teeth are formed by structured segments of the opposing ring sheets.

14. The sensor arrangement according to claim 13 , wherein the structured segments of the opposing ring sheets taper towards a center of a respective ring sheet.

15. A torque sensor, comprising:
a first shaft having an axis;
a second shaft provided coaxially with the first shaft;
a structure connected to the first shaft; and
wherein the structure comprises a plurality of magnetic elements, each of the plurality of magnetic elements having a magnetic moment which is parallel to the axis of the first shaft, and
wherein the plurality of magnetic elements is arranged in holes of the structure, the holes extending in a direction parallel to the axis of the first shaft from a first end face of the structure to a second end face of the structure.

16. The torque sensor according to claim 15 , wherein the plurality of magnetic elements have end faces which are flush with end faces of the structure.

17. The torque sensor according to claim 15 , wherein the plurality of magnetic elements is provided with alternating polarity such that adjacent magnetic elements have magnetic moments in opposite directions.

18. The torque sensor according to claim 15 , wherein the structure is a disc-shaped circular structure.

19. The torque sensor according to claim 18 , wherein the plurality of magnetic elements is distributed along a circle centered with respect to a center of the disc-shaped circular structure, the plurality of magnetic elements having a distance from the center less than a radius of the disc-shaped circular structure.

20. The torque sensor according to claim 15 , wherein the structure is arranged in a hollow structure, the hollow structure comprising a plurality of magnetic conductive teeth.

21. The torque sensor according to claim 20 , wherein the plurality of magnetic conductive teeth are provided on end faces of the hollow structure to oppose each other, wherein the structure extends between respective opposing teeth.

22. The torque sensor according to claim 20 , wherein each of the plurality of magnetic conductive teeth extends in a direction towards a center line of the hollow structure.

23. The torque sensor according to claim 22 , wherein each of the plurality of magnetic conductive teeth tapers in a direction towards the center line of the hollow disc structure.

24. A method of determining a torque, comprising:
detecting a change of a magnetic field, the change of magnetic field being caused by a relative rotation around a first axis between a first structure having a plurality of magnetic elements and a second hollow structure having a plurality of magnetic conductive teeth, the plurality of magnetic elements each having a magnetic moment in a direction parallel to the first axis, wherein the plurality of magnetic elements is arranged in holes of the first structure, the holes extending in a direction parallel to the first axis from a first end face of the first structure to a second end face of the first structure; and
based on the detected change of the magnetic field, determining an applied torque.

Assignees

• Infineon Technologies Ag

Inventors

• Zhong Hongsheng
• Zhong Xiulin
• You Wei
• Foo Yoon Fatt Francis
• Guan Lifeng
• Su Li
• Wang Ling

Classifications

• G01L3/101 Primary

  involving magnetic or electromagnetic means · CPC title

• G01L3/104 Primary

  involving permanent magnets · CPC title

• B62D6/10 Primary

  characterised by means for sensing {or determining} torque · CPC title

• G01L3/10

  involving electric or magnetic means for indicating · CPC title