WEIGHT-OPTIMIZED ROTOR SHAFT, AND PROCESS FOR MANUFACTURING SAME

Abstract

The present invention relates to a rotor shaft and a method for producing a rotor shaft.

Claims

1-10. (canceled)

11. A rotor shaft having a hollow shaft body having at least one profiling which extends externally on the shaft body in the longitudinal extent of the shaft body, wherein the shaft body is pressure-rolled and internally on the shaft body there is provided at least one bead-like profiling which extends in the longitudinal extent of the shaft body parallel with the profiling which extends externally on the shaft body.

12. The rotor shaft as claimed in claim 11, wherein the rotor shaft has at least one end portion which is arranged at one end of the shaft body and which terminates the end of the shaft body.

13. The rotor shaft as claimed in claim 12, wherein the rotor shaft has end portions which are arranged at both ends of the shaft body and which terminate the ends of the shaft body.

14. The rotor shaft as claimed in claim 13, wherein the end portion has a journal portion.

15. The rotor shaft as claimed in claim 14, wherein the shaft body and an end portion of the rotor shaft are pressure-rolled.

16. A method for producing a rotor shaft having a hollow shaft body having at least one profiling which extends externally on the shaft body in the longitudinal extent of the shaft body, wherein the method comprises the following steps: providing a metal semi-finished product; forming a hollow shaft body from the semi-finished product; producing at least one profiling which extends externally on the shaft body in the longitudinal extent of the shaft body during the forming operation or after the forming operation; wherein the forming is carried out by means of pressure-rolling in one or more pressure-rolling steps, wherein in the pressure-rolling step or in one of the pressure-rolling steps in the longitudinal extent of the shaft body at least one bead-like profiling is produced internally on the shaft body.

17. The method as claimed in claim 16, wherein the at least one profiling which extends externally on the shaft body in the longitudinal extent of the shaft body is produced in the region of and parallel at the side facing away from the bead-like profiling.

18. The method as claimed in claim 17, wherein the at least one externally extending profiling is produced in a cutting manner.

19. The method as claimed in claim 18, wherein the internally provided bead-like profiling and the externally extending profiling are sized in such a manner that the thickness in the region of the profilings does not fall below the final thickness of the completed shaft body.

20. The method as claimed in one of claim 19, wherein there is also formed from the semi-finished product an end portion which is produced before or after the forming of the shaft body.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0023] The invention will be explained in greater detail below with reference to the drawings. Identical components are given the same reference numerals. In detail:

[0024] FIG. 1 shows a plan view of a section of a conventional rotor shaft and

[0025] FIG. 2 shows a perspective view of a section of a rotor shaft according to an embodiment according to the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0026] FIG. 1 shows an example of a rotor shaft (1) which has been produced in a conventional manner. The rotor shaft (1) is in the form of a hollow shaft body (2) and has a profiling (3) in the longitudinal extent of the shaft body (2), in this instance in the form of two grooves (3) which have been introduced for positive-locking receiving and connection of a rotor plate assembly which is not illustrated. The reduction of the thickness of the shaft body (2) in the region of the profiling (3) can be clearly seen. The thickness (d1) of the shaft body (2) is reduced by the profiling (3) in this region to the thickness (d2). The shaft body (2) would have sufficient dimensions with the thickness (d2) but, as a result of the introduction of the profiling (3) in the form of the grooves, the difference of (d1) and (d2) is increased and ultimately in final use also moved as an unnecessary additional weight.

[0027] FIG. 2 shows an embodiment according to the invention of a rotor shaft (1) which in comparison with the conventional configuration in FIG. 1 in addition to a lower and substantially more uniform thickness (d2) of the shaft body (2) additionally has in the region of the at least one profiling (3) at least one bead-like profiling (4) which extends internally and parallel with the profiling (3). The bead-like profiling (4) which is provided at the inner side and the profiling (3) which extends at the outer side are sized in such a manner that the thickness in the region of the profilings (3, 4) does not fall below the final thickness (d2) of the completed shaft body (2). The rotor shaft (1) according to the invention can be produced for the most part by means of pressure-rolling, wherein the shaft body (2) and an end portion (5) of the rotor shaft (1) are produced integrally from a semi-finished product. The rotor shaft (1) is completed by a separate component which forms the second end portion and which is connected to the open end of the shaft body (2) in a materially engaging, positive-locking and/or non-positive-locking manner, not illustrated in this instance. The end portions (5) also have journal portions which are not illustrated for rotatable bearing.

[0028] The features described, where technically possible, can all be combined with each other. Rotor shafts (1) according to the invention are used in electric drives, in particular in electric motors of road vehicles. The profiling (3) which extends externally on the shaft body (2) in the longitudinal extent of the shaft body (3) may be in the form of a recess and/or groove. Other geometric shapes, which are suitable for receiving a rotor plate assembly in a positive-locking manner are also conceivable. Furthermore, the profiling (3) which extends externally can be limited to a (part) portion or extend continuously on the shaft body (2). A plurality of profilings (2) which are distributed over the circumference, see FIG. 2, in the longitudinal extent may also be present in (part) portions or in a continuous manner. The bead-like profiling (4) is always arranged in the region and parallel with the externally extending profiling (3).