METHOD AND DEVICE FOR JOINING A REINFORCEMENT SLEEVE ONTO A ROTOR OF AN ELECTRIC MOTOR

Abstract

A method and a device for joining a reinforcement sleeve onto a rotor of an electric motor. The method includes providing the reinforcement sleeve and the rotor, the reinforcement sleeve has a cylindrical inner periphery which is undersized with respect to a cylindrical outer periphery of the rotor; attaching at least two vacuum cups onto an outer lateral surface of the reinforcement sleeve, such that the vacuum cups adhere to the outer lateral surface of the reinforcement sleeve in a reversibly detachable manner on account of a vacuum generated between the vacuum cup and the outer lateral surface; and joining the reinforcement sleeve onto the rotor, in that the rotor is pressed into the reinforcement sleeve in a pressing direction.

Claims

1-15. (canceled)

16. A method for joining a reinforcement sleeve onto a rotor of an electric motor, the method comprises: providing the reinforcement sleeve and the rotor, wherein the reinforcement sleeve has a cylindrical inner periphery which is undersized with respect to a cylindrical outer periphery of the rotor; attaching at least two vacuum cups onto an outer lateral surface of the reinforcement sleeve, such that the vacuum cups adhere to the outer lateral surface of the reinforcement sleeve in a reversibly detachable manner on account of a vacuum generated between the vacuum cup and the outer lateral surface; and joining the reinforcement sleeve onto the rotor, in that the rotor is pressed into the reinforcement sleeve in a pressing direction, wherein forces acting in the pressing direction are transferred from the vacuum cups to the reinforcement sleeve.

17. The method according to claim 16, wherein the reinforcement sleeve has a wall thickness of less than 2 mm.

18. The method according to claim 16, wherein the reinforcement sleeve is formed using fiber-reinforced, in particular carbon fiber-reinforced or glass fiber-reinforced, plastics material.

19. The method according to claim 16, wherein the vacuum cups have a contour complementary to the outer lateral surface of the reinforcement sleeve, on a side facing the outer lateral surface of the reinforcement sleeve.

20. The method according to claim 16, wherein the vacuum cups have an annular segment-shaped contour on a side facing the outer lateral surface of the reinforcement sleeve.

21. The method according to claim 16, wherein the vacuum cups have a friction-enhancing surface on a side facing the reinforcement sleeve.

22. The method according to claim 16, wherein forces transferred from the vacuum cups to the reinforcement sleeve are generated in a temporally oscillating manner.

23. The method according to claim 16, wherein a liquid is introduced between an outer peripheral surface of the rotor and an inner peripheral surface of the reinforcement sleeve.

24. The method according to claim 16, wherein the rotor is cooled prior to joining.

25. A device for joining a reinforcement sleeve onto a rotor of an electric motor, wherein the device is designed to carry out the method according to claim 16.

26. A device, comprising: a pressing tool, which is designed to displace the rotor and the reinforcement sleeve relative to one another, in an opposing pressing direction, during a joining process in which the reinforcement sleeve is joined onto the rotor, at least two vacuum cups, which are in each case designed to generate a vacuum between the vacuum cup and an outer lateral surface of the reinforcement sleeve and to thereby cause the vacuum cup to adhere to the outer lateral surface of the reinforcement sleeve in a reversibly detachable manner, wherein the pressing tool and/or the vacuum cups are designed such that, during the joining process, forces acting in the pressing direction are transferred from the vacuum cups to the reinforcement sleeve.

27. The device according to claim 26, wherein the vacuum cups have a contour complementary to the outer lateral surface of the reinforcement sleeve, on a side facing the outer lateral surface of the reinforcement sleeve.

28. The device according to claim 26, wherein the vacuum cups have an annular segment-shaped contour on a side facing the outer lateral surface of the reinforcement sleeve.

29. The device according to claim 26, wherein the vacuum cups have a friction-enhancing surface on a side facing the reinforcement sleeve.

30. The device according to claim 26, further comprising an oscillation generator which is designed to generate forces, transferred from the vacuum

31. The device according to claim 26, wherein the device is designed to carry out the method according to claim 16.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0049] In the following, advantageous embodiments of the invention are explained in further detail with reference to the accompanying drawings, neither the drawings nor the explanations being intended to be interpreted as limiting the invention in any way.

[0050] FIG. 1 is a longitudinal sectional view through a device for joining a reinforcement sleeve onto a rotor of an electric motor according to one embodiment of the present invention.

[0051] FIG. 2 is a perspective view of a vacuum cup by way of example for a device according to one embodiment of the present invention.

[0052] FIG. 3 is a cross-section through a device according to one embodiment of the present invention.

[0053] FIG. 4 is a cross-section through a device according to a further embodiment of the present invention.

[0054] The figures are merely schematic and not to scale. The same reference signs in the different drawings denote identical or identically acting features.

DETAILED DESCRIPTION

[0055] FIG. 1 shows a device 1 according to the invention for joining a reinforcement sleeve 3 onto a rotor 5 of an electric motor. In this case, the reinforcement sleeve 3 is designed so as to be circular cylindrical, has a small wall thickness of for example less than 0.5 mm, and consists of carbon fiber-reinforced plastics material. The reinforcement sleeve 3 is intended to be joined onto the elongate rotor 5 in such a way that it surrounds an outer periphery of the rotor 5, in a press fit. The rotor 5, composed of a plurality of components, is thus bandaged and stabilized by the reinforcement sleeve 3 in the radial direction.

[0056] The device 1 comprises a pressing tool 7 and two vacuum cups 9. During a joining process, the pressing tool 7 may press the reinforcement sleeve 3 and the rotor 5 in opposing pressing directions 15 in each case, and thus displace them relative to one another. In the example shown, for this purpose the rotor 5 and a cone 23 arranged thereabove are held vertically on a base plate 11, while a press ram 13 of the pressing tool 7 pushes the reinforcement sleeve 3 downwards over the rotor 5, from above, in a pressing direction 15 in parallel with an axial direction of the rotor 5. For this purpose, the press ram 13 presses, with a lower end face 37, onto a press ring 17. The press ring 17 in turn presses on an upper end face 25 of the reinforcement sleeve 3, and thus pushes the inner peripheral surface 19 thereof successively along an outer peripheral surface 21 of the rotor 5, in the pressing direction 15. In this case, the reinforcement sleeve 3 is subjected to significant mechanical loading at its upper end face 25.

[0057] In order that the reinforcement sleeve 3 does not have to be joined over the rotor 5 exclusively by means of the pressure exerted on the upper end face 25 of said reinforcement sleeve via the press ring 17, the device 1 further comprises at least two vacuum cups 9. The vacuum cups 9 are designed to generate a negative pressure between themselves and an outer lateral surface 27 of the reinforcement sleeve 3, and to thereby suction onto the outer lateral surface 27 of the reinforcement sleeve 3 in a reversibly detachable manner. For this purpose, the vacuum cups 9 may be connected to a pump (not shown) by hollow suction lines 29, for example, via which pump the desired vacuum is generated.

[0058] A suction element 31 of a vacuum cup 9 of this kind is shown in FIG. 2. The suction element 31 of the vacuum cup 9 has a contour complementary to the outer lateral surface 27 of the reinforcement sleeve 3, on a side 33 facing the outer lateral surface 27 of the reinforcement sleeve 3. In the example shown, said side 33 is designed as a segment of a cylinder surface, such that the suction element 31 may cling to the cylindrical outer lateral surface 27 of the reinforcement sleeve in a complementary manner. At least on the side 33 facing the reinforcement sleeve 3, the suction element 31 may consist of a flexible, for example rubbery, material. In a center of said side 33, the suction element 31 comprises a plurality of suction intakes 35, out of which air may be suctioned for example via a suction line 29 connected thereto, and thus the desired vacuum between the suction element 31 of the vacuum cup 9 and the reinforcement sleeve 3 may be generated. Furthermore, the side 33 facing the reinforcement sleeve 3 may comprise a friction-enhancing surface, for example in that said surface is roughened or provided with a macroscopic texture.

[0059] In order to then assist the device 1 when joining the reinforcement sleeve 3 onto the rotor 5, the pressing tool 7 and/or the vacuum cups 9 are designed such that, during the joining process, forces acting in the pressing direction 15 are transferred from the vacuum cups 9 to the reinforcement sleeve 3. In the example shown in FIG. 1, for this purpose the two suction elements 31 of the vacuum cups 9 are supported on the lower end face 37 of the press ram 13 by means of support structures 39. Accordingly, the press ram 13 presses not only the press ring 17, and via said ring the upper end face 25 of the reinforcement sleeve 3, downwards in the pressing direction 15, but rather also the two vacuum cups 9 and via these the outer lateral surface 27 of the reinforcement sleeve 3.

[0060] FIGS. 3 and 4 are cross-sectional views of two possible embodiments of how the vacuum cups 9 may be formed, may be arranged on the reinforcement sleeve 3, and may interact with the reinforcement sleeve 3.

[0061] In the embodiment shown in FIG. 3, the suction elements 31 of the vacuum cups 9 are designed so as to be relatively small and box-like. Accordingly, the vacuum cups 9 contact the outer lateral surface 27 of the reinforcement sleeve 3 merely in a quasi point-wise manner or on relatively small surfaces with respect to an overall surface of the lateral surface 27. In the example, three vacuum cups 9 are provided, which are arranged in an equidistant manner along the periphery of the lateral surface 27.

[0062] In the embodiment shown in FIG. 4, the suction elements 31 are designed having an annular segment-shaped contour. Only two vacuum cups 9 are provided. In this case, each of the two suction elements 31 clings to the cylindrical outer lateral surface 27 of the reinforcement sleeve 3, by means of the side 33 of said suction element facing the reinforcement sleeve 3, which side approximately forms half a cylinder surface. In this case, channels 43 (shown in dashed lines) may be provided in the suction element 31, via which channels a plurality of suction intakes 35 are connected to the respective suction line 29, such that the suction element 31 may adhere to the reinforcement sleeve 3 by means of generation of a negative pressure.

[0063] As is indicated merely in a highly schematic manner in FIG. 4, the device 1 may additionally comprise an oscillation generator 45. Said oscillation generator 45 may cause the vacuum cups 9 to be subjected to oscillating forces, and to transfer these in turn to the reinforcement sleeve 3. The oscillating forces may act in different directions. By way of example, forces are indicated in FIG. 4 which press in the peripheral direction 47 and/or in the radial direction 49, it also being possible for forces acting in the axial direction (i.e. orthogonally to the image plane in FIG. 4) to be transferred from the oscillation generator 45 to the respective suction elements 31 of the vacuum cups 9. The joining process may be assisted by virtue of the oscillating forces.

[0064] It is noted in addition that terms such as “comprising” or “having” do not exclude any other elements or steps, and terms such as “a” or “one” do not exclude a plurality. It is furthermore noted that features or steps that have been described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered limiting.

LIST OF REFERENCE SIGNS

[0065] 1 device [0066] 3 reinforcement sleeve [0067] 5 rotor [0068] 7 pressing tool [0069] 9 vacuum cups [0070] 11 base plate [0071] 13 press ram [0072] 15 pressing direction [0073] 17 press ring [0074] 19 inner peripheral surface of the reinforcement sleeve [0075] 21 outer peripheral surface of the rotor [0076] 23 cone [0077] 25 upper end face of the reinforcement sleeve [0078] 27 outer lateral surface of the reinforcement sleeve [0079] 29 suction line [0080] 31 suction element [0081] 33 side of the vacuum cup facing the reinforcement sleeve [0082] 34 friction-enhancing surface [0083] 35 suction intakes [0084] 37 lower end face of the press ram [0085] 39 support structure [0086] 43 channel [0087] 45 oscillation generator [0088] 47 peripheral direction [0089] 49 radial direction