Device and method for torque measurement

Patent metadata

Field	Value
Publication number	US-10866152-B2
Application number	US-201916428128-A
Country	US
Kind code	B2
Filing date	May 31, 2019
Priority date	Jun 6, 2018
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A concept for torque measurement on a shaft is described. To that end, millimeter waves are transmitted in the direction of a first encoder structure, which is coupled to a first shaft section of the shaft for conjoint rotation and is arranged around the shaft, and in the direction of a second encoder structure, which is coupled to a second shaft section of the shaft for conjoint rotation and is arranged around the shaft. The first encoder structure and the second encoder structure are rotatable relative to one another in the case of a torque to be transmitted via the shaft. At least one reception signal is generated on the basis of millimeter waves reflected or transmitted by the first and second encoder structures. A torque transmitted using the shaft is determined on the basis of the at least one reception signal.

First claim

What is claimed is:

1. A device for torque measurement on a shaft, comprising:
a first encoder structure coupled to a first shaft section of the shaft for conjoint rotation and arranged around the shaft;
a second encoder structure coupled to a second shaft section of the shaft for conjoint rotation and arranged around the shaft;
wherein the first encoder structure and the second encoder structure are rotatable relative to one another in a case of a torque to be transmitted via the shaft;

at least one transmitter configured to transmit millimeter waves in a direction towards the first encoder structure and the second encoder structure;
at least one receiver configured to:
receive the millimeter waves reflected by the first encoder structure and the second encoder structure or other millimeter waves allowed to pass by the first encoder structure and the second encoder structure,
generate at least one reception signal; and

a processor configured to determine the torque transmitted by the shaft based on the at least one reception signal.

2. The device as claimed in claim 1 , wherein the first encoder structure has first fingers coupled to the first shaft section for conjoint rotation and arranged around the shaft, wherein the second encoder structure has second fingers coupled to the second shaft section for conjoint rotation and arranged around the shaft, and wherein the first fingers and the second fingers intermesh and are arranged rotatably relative to one another.

3. The device as claimed in claim 2 , wherein the first fingers have reflectivity for the millimeter waves which are different than reflectivity of the second fingers.

4. The device as claimed in claim 2 , wherein a geometry of the first fingers is different than a geometry of the second fingers.

5. The device as claimed in claim 4 , wherein the first fingers and the second fingers are embodied with different widths and/or have differently curved surfaces.

6. The device as claimed in claim 2 , wherein the first fingers are arranged on a first radius around the shaft and the second fingers are arranged on a second radius around the shaft, and wherein the first radius is different than the second radius.

7. The device as claimed in claim 2 , wherein, within the first fingers and the second fingers arranged around the shaft, a cylinder lateral surface having predefined reflection properties for the millimeter waves is arranged around the shaft.

8. The device as claimed in claim 7 , wherein a radial distance between the cylinder lateral surface and the first fingers and/or the second fingers is an odd multiple of one quarter of a wavelength of the millimeter waves.

9. The device as claimed in claim 2 , wherein, within the first fingers and the second fingers arranged around the shaft, there is arranged a structure that prevents a reflection of millimeter waves back to the at least one receiver and enables non-reflected millimeter waves to enter a space within the first fingers and the second fingers through gaps between the first fingers and the second fingers.

10. The device as claimed in claim 9 , wherein the structure is configured to absorb millimeter waves that have entered the space.

11. The device as claimed in claim 9 , wherein the structure is configured to reflect millimeter waves that have entered the space within the first fingers and the second fingers in such a way that the reflected millimeter waves no longer exit from the space within the first fingers and the second fingers.

12. The device as claimed in claim 2 , wherein the at least one receiver has an antenna array having a plurality of antenna elements,
wherein a first antenna element of the antenna array, in a case of a position of the first encoder structure and the second encoder structure, has a first angular position between two adjacent fingers of a same encoder structure, and
wherein a second antenna element of the antenna array, in the case of the position of the first encoder structure and the second encoder structure, has a second angular position between two adjacent fingers of a same encoder structure,
the second angular position being different than the first angular position.

13. The device as claimed in claim 1 , wherein the first encoder structure is embodied identically to the second encoder structure.

14. The device as claimed in claim 1 , wherein the first encoder structure comprises a first encoder disk and the second encoder structure comprises a second encoder disk embodied identically to the first encoder disk, wherein the first encoder disk and the second encoder disk are arranged at a distance along the shaft and each comprises predefined regions of different reflectivity for the millimeter waves.

15. The device as claimed in claim 1 , wherein the processor is configured to determine from the at least one reception signal an order of the first encoder structure and the second encoder structure rotating past the at least one receiver, and to determine a rotation direction of the shaft from the order.

16. The device as claimed in claim 1 , wherein the processor is configured to determine a rotation angle between the first encoder structure and the second encoder structure from the at least one reception signal, and to determine the torque from the rotation angle.

17. The device as claimed in claim 1 , wherein the shaft has, between the first shaft section and the second shaft section, a region having a lower material stiffness than the first shaft section and the second shaft section.

18. The device as claimed in claim 17 , wherein the region having the lower material stiffness comprises a different material and/or has a smaller diameter than the first shaft section and the second shaft section.

19. The device as claimed in claim 1 , wherein the at least one transmitter and/or the at least one receiver comprise at least one flexible waveguide configured to transport the millimeter waves from or to the first encoder structure or the second encoder structure.

20. A method for torque measurement on a shaft, comprising:
transmitting millimeter waves in a direction towards a first encoder structure and a second encoder structure,
wherein the first encoder structure is coupled to a first shaft section of the shaft for conjoint rotation and is arranged around the shaft,
wherein the second encoder structure is coupled to a second shaft section of the shaft for conjoint rotation and is arranged around the shaft, and
wherein the first encoder structure and the second encoder structure are rotatable relative to one another in a case of a torque to be transmitted via the shaft;

generating at least one reception signal based on millimeter waves reflected or transmitted by the first encoder structure and the second encoder structure; and
determining the torque transmitted by the shaft based on the at least one reception signal.

Assignees

• Infineon Technologies Ag

Inventors

• Hammerschmidt Dirk
• Michenthaler Christof

Classifications

• G01L3/00 Primary

  Measuring torque, work, mechanical power, or mechanical efficiency, in general · CPC title

• G01L3/1435 Primary

  involving magnetic or electromagnetic means · CPC title