Torque-measuring shaft

1. A torque-measuring shaft comprising:

(a) a shaft axis;

(b) measuring shaft disposed on the shaft axis, loadable in torsion and having at least one rotationally symmetric surface region disposed coaxially with the shaft axis;

(c) a measuring device disposed on the measuring shaft for measuring a torsion of the measuring shaft;

(d) a material weakening disposed in a radial direction inside the measuring shaft eccentrically relative to the shaft axis; and

(e) a stiffening element;

wherein the material weakening comprises, in the measuring shaft, at least one recess disposed in the radial direction inside the measuring shaft eccentrically relative to the shaft axis;

wherein the stiffening element is disposed in the at least one recess;

wherein the at least one recess has rims; and

wherein the stiffening element comes into contact with the rims of the at least one recess.

2. The torque-measuring shaft according to claim 1 , wherein the stiffening element comes into contact with the rims under torsion.

3. The torque-measuring shaft according to claim 1 , wherein the stiffening element is formed in one piece with the measuring shaft.

4. The torque-measuring shaft according to claim 1 , wherein the at least one recess perforates the measuring shaft.

5. The torque-measuring shaft according to claim 4 , wherein the at least one recess perforates the measuring shaft parallel to the shaft axis.

6. The torque-measuring shaft according to claim 1 , wherein at least one recess is provided with a cover on at least one end of the measuring shaft.

7. The torque-measuring shaft according to claim 1 , wherein the at least one recess is provided with first and second cover on first and second ends, respectively, of the measuring shaft.

8. The torque-measuring shaft according to claim 1 , further comprising a measuring web disposed between the material weakening and the at least one rotationally symmetric surface region, wherein the measuring web has a minimum width perpendicular to an axial alignment of the measuring Web to the shaft axis and starting from the shaft axis broadens steadily up to a radial extent of the at least one recess.

9. The torque-measuring shaft according to claim 8 , wherein the measuring web is formed in one piece with the measuring shaft.

10. The torque-measuring shaft according to claim 8 , comprising at least two material weakenings disposed in the radial direction inside the measuring shaft, respectively eccentrically relative to the shaft axis and mutually symmetrically relative to the shaft axis.

11. The torque-measuring shaft according to claim 8 , comprising at least four material weakenings disposed in the direction inside the measuring shaft, respectively eccentrically relative to the shaft axis and mutually symmetrically relative to the shaft axis.

12. The torque-measuring shaft according to claim 10 , wherein the material weakening are respectively identically configured.

13. The torque-measuring shaft according to claim 1 , wherein the measuring shaft is formed in one piece.

14. The torque-measuring shaft according to claim 10 , wherein the measuring device comprises a plurality of strain gauges.

15. The torque-measuring shaft according to claim 10 , wherein the measuring device, is mounted on the at least one rotationally symmetric surface region.

16. The torque-measuring shaft according to claim 14 , wherein the strain gauges are disposed near the material weakenings or the measuring web.

17. The torque-measuring shaft according to claim 15 , wherein the measuring device is mounted on the at least one rotationally symmetric surface region near the material weakenings or the measuring web.

18. The torque-measuring shaft according to claim 1 , further comprising a flange attached to or formed in one piece with the measuring shaft on at least one end of the measuring shaft.

19. The torque-measuring shaft according to claim 1 , further comprising first and second flanges attached to or formed in one piece with the measuring shaft on first and second ends, respectively, of the measuring shaft.

20. A torque-measuring shaft comprising:

(a) a shaft axis;

(b) a measuring shaft disposed on the shaft axis, loadable in torsion and having at least one rotationally symmetric surface region disposed coaxially with the shaft axis;

(c) a measuring device disposed on the measuring shaft for measuring a torsion of the measuring shaft; and

(d) a material weakening disposed in a radial direction inside the measuring shaft eccentrically relative to the shaft axis;

wherein the material weakening is convex in a direction of the at least one rotationally symmetric surface region.

21. The torque-measuring shaft according to claim 20 , wherein the measuring shaft is formed in one piece.

22. The torque-measuring shaft according to claim 20 , further comprising a flange attached to or formed in one piece with the measuring shaft on at least one end of the measuring shaft.

23. A torque-measuring shaft comprising:

(f) a shaft axis;

(g) a measuring shaft disposed on the shaft axis, loadable in torsion and having at least one rotationally symmetric surface region disposed coaxially with the shaft axis;

(h) a measuring device disposed on the measuring shaft for measuring a torsion on of the measuring shaft; and

(i) a material weakening disposed in a radial direction inside the measuring shaft eccentrically relative to the shaft axis;

wherein the material weakening comprises, in the measuring shaft, at least one recess disposed in the radial direction inside the measuring shaft eccentrically relative to the shaft axis; and

wherein the at least one recess perforates the measuring shaft parallel to the shaft axis.

24. The torque-measuring shaft according to claim 23 , wherein the material weakening is convex in a direction of the at least one rotationally symmetric surface region.

25. The torque-measuring shaft according to claim 23 , wherein the measuring shaft is formed in one piece.