METHOD FOR PRODUCING A ROTOR FOR AN ELECTRIC ROTATING MACHINE

Abstract

A method for producing a rotor for an electric rotating machine includes spraying in a rolling manner a first metallic material and a second metallic material, which is different from the first metallic material, onto at least part of a substantially cylindrical outer surface of a shaft body by a thermal spraying method to form on the shaft body a coating which forms at least part of a squirrel cage.

Claims

1.-15. (canceled)

16. A method for producing a rotor for an electric rotating machine, said method comprising spraying in a rolling manner a first metallic material and a second metallic material, which is different from the first metallic material, onto at least part of a substantially cylindrical outer surface of a shaft body by a thermal spraying method to form on the shaft body a coating which forms at least part of a squirrel cage.

17. The method of claim 16, wherein the thermal spraying method includes cold gas spraying.

18. The method of claim 16, wherein the second metallic material is a soft-magnetic material.

19. The method of claim 16, further comprising producing the shaft body from the second metallic material.

20. The method of claim 16, wherein the at least part of the squirrel cage is formed by the first metallic material.

21. The method of claim 20, wherein the squirrel cage is embedded completely into the rotor.

22. The method of claim 16, wherein the first metallic material has a conductivity of more than 40 MS/m.

23. The method of claim 16, wherein the first metallic material is sprayed with a first spraying device and the second metallic material is sprayed with a second spraying device.

24. The method of claim 16, wherein the spraying of the first and second metallic materials in a rolling manner is implemented alternately and/or on an evolvent path.

25. The method of claim 16, further comprising spraying a third material onto at least part of the substantially cylindrical outer surface of the shaft body such as to insulate the first and second metallic materials from one another.

26. The method of claim 25, further comprising connecting at least two of the first and second metallic materials and the third material of the coating in a form-fit manner.

27. A rotor for an electric rotating machine, said rotor comprising: a shaft body; and a squirrel cage formed by a coating made of a first metallic material and a second metallic material, which is different from the first metallic material, and applied onto at least part of a substantially cylindrical outer surface of the shaft body.

28. The rotor of claim 27, wherein the rotor is configured for operation with a rotational speed of at least 5,000 rpm.

29. The rotor of claim 27, wherein the second metallic material is a soft-magnetic material.

30. The rotor of claim 29, wherein the shaft body is made from the second metallic material, said at least part of the squirrel cage being formed by the first metallic material.

31. The rotor of claim 30, wherein the first metallic material has a conductivity of more than 40 MS/m.

32. The rotor of claim 27, wherein the coating includes a third material to insulate the first and second metallic materials from one another.

33. The rotor of claim 32, wherein at least two of the first and second metallic materials and the third material of the coating are connected in a form-fit manner.

34. An electric rotating machine, comprising a rotor, said rotor comprising a shaft body, and a squirrel cage formed by a coating made of a first metallic material and a second metallic material, which is different from the first metallic material, and applied onto at least part of a substantially cylindrical outer surface of the shaft body.

Description

[0029] The invention is described and explained below in more detail on the basis of the exemplary embodiments shown in the Figures. The drawings show:

[0030] FIG. 1 a longitudinal section of an electric rotating machine.

[0031] FIG. 2 a side view of a rotor with a squirrel cage,

[0032] FIG. 3 a cross-section of a first embodiment of a rotor with a coating,

[0033] FIG. 4 a cross-section of a second embodiment of a rotor with a coating,

[0034] FIG. 5 an enlarged cross-section of a third embodiment of a rotor with a coating,

[0035] FIG. 6 an enlarged cross-section of a fourth embodiment of a rotor with a coating,

[0036] FIG. 7 a schematic representation of a first method for producing a rotor and

[0037] FIG. 8 a schematic representation of a second method for producing a rotor.

[0038] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments in each case represent individual features of the invention which are to be considered independently of one another and which further develop the invention in each case also independently of one another and are thus also to be considered, individually or in a different combination to that shown, as a component part of the invention. Furthermore, the described embodiments can also be extended by further features of the invention which are already described.

[0039] The same reference characters have the same meaning in the various figures.

[0040] FIG. 1 shows a longitudinal section of an electric rotating machine 2, which is embodied as an asynchronous machine. The asynchronous machine has a rotor 6 which can be rotated about an axis of rotation 4 and a stator 8 which surrounds the rotor 6. A gap 10, which is embodied in particular as an air gap, is located between the rotor 6 and the stator 8. The axis of rotation 4 defines an axial direction, a radial direction and a peripheral direction. The rotor 6 comprises a solid shaft body 12 with a coating 14, which has a magnet pole-generating element. The magnet pole-generating element is configured as a squirrel cage 16. Alternatively, the electric rotating machine 2 is embodied as an asynchronous machine, wherein the rotor 6 of the synchronous machine has permanent magnets or poles with exciter windings as a magnet pole-generating element. The stator 8 comprises a magnetic field-guiding stator element 18, which is embodied as a laminated core for suppressing eddy currents, and a stator winding 20, which embodies winding heads 22 at the axial ends of the stator laminated core.

[0041] FIG. 2 shows a side view of a rotor 6 with a squirrel cage 16. The squirrel cage 16 has short-circuit rods 16a, which are connected at their axial ends by way of a short-circuit ring 16b in each case. The coating 14 is applied with a thermal spraying method and is configured so that the rotor 6 is substantially cylindrical and the squirrel cage 16 is embedded completely into the coating 14 of the rotor 6. Thermal spraying methods are for instance arc spraying, plasma spraying, flame spraying or cold gas spraying. The solid shaft body 12 is produced from a soft-magnetic material. The coating 14 comprises a first metallic material and a second metallic material, wherein the second metallic material is a soft-magnetic material and substantially corresponds to the soft-magnetic material of the shaft body 12. The first metallic material of the squirrel cage 16, for instance copper or a copper alloy, has a conductivity of more than 40 MS/m. The coating 14, which surrounds the squirrel cage 16, is further connected at least with a material-bonded connection with the shaft body 12 by means of the thermal spraying method, so that the rotor 6, which has a diameter d of at least 30 cm, can be operated with a power of at least 1 MW and a rotational speed of at least 10,000 rpm. For instance, with cold gas spraying, solid body particles which are accelerated by way of a gas flow strike the shaft body 12 with a high kinetic energy of this type so that a material-bonded connection is produced by way of diffusion mechanisms. The further embodiment of the rotor 6 in FIG. 2 corresponds to that in FIG. 1.

[0042] FIG. 3 shows a cross-section of a first embodiment of a rotor 6 with a coating 14. The coating 14 comprises metallic solid body particles, which are sprayed by means of cold gas spraying onto the substantially cylindrical outer surface 24 of the shaft body 12. The coating comprises solid body particles made from a first metallic material 26 and solid body particles made from a second metallic material 28, wherein the first metallic material 26 and the second metallic material 28 are sprayed directly onto the substantially cylindrical outer surface 24 of the shaft body 12 with a first spraying device 28 and a second spraying device 32 in each instance. The squirrel cage 16 is, as in FIG. 2, formed from solid body particles of the first metallic material 28. The second metallic material 28, as in FIG. 2, is a soft-magnetic material, for instance steel, and corresponds substantially to the soft-magnetic material of the shaft body 12. The squirrel cage 16 is embedded completely into the rotor 6. At least the short-circuit rods 16a of the squirrel cage 16 have cross-sectionally a circular ring sector-shaped contour. The contour is approximately rectangular or square. Such a rectangular or square contour of the conductor of the squirrel cage 16 achieves a high current compatibility. The further embodiment of the rotor 6 in FIG. 3 corresponds to that in FIG. 2.

[0043] FIG. 4 shows a cross-section of a second embodiment of a rotor 6 with a coating 14, wherein at least the short-circuit rods 16a of the squirrel cage 16 have a rounded contour cross-sectionally. By way of example, the contour of the short-circuit rods 16a are shown in a U shape. The squirrel cage 16 is embedded completely into the coating 14 of the rotor 6. The further embodiment of the rotor 6 in FIG. 4 corresponds to that in FIG. 3.

[0044] FIG. 5 shows an enlarged cross-section of a third embodiment of a rotor 6 with a coating 14, wherein the first material 26 and the second material 26 are additionally connected in a form fit manner by a, for instance, sawtooth-shaped, rib structure. The squirrel cage 16 is embedded completely into the coating 14 of the rotor 6. The further embodiment of the rotor 6 in FIG. 5 corresponds to that in FIG. 3.

[0045] FIG. 6 shows an enlarged cross-section of a fourth embodiment of a rotor 6 with a coating 14, wherein the coating The coating comprises solid body particles made from a first metallic material 26, a second metallic material 28 and a third material 36. The materials 26, 28, 36 are sprayed onto the substantially cylindrical outer surface 24 of the shaft body 12 by means of a different spraying device 30, 32. The spraying devices 30, 32 are not shown in FIG. 6 for the sake of clarity.

[0046] The third material 36 is an electrically conductive material, which has silver, brass, zinc or aluminum, for instance, and differs from the first metallic material 26 as a result of its electric, thermal and/or mechanical properties. On account of an electrically conductive third material 36, a mechanical stability of the rotor 6 is improved and/or the losses occurring during operation are reduced, for instance. The third material 36 is assigned to the squirrel cage 16 and connects the first metallic material 26 with the second metallic material 28. Alternatively, the third material 36 is an electrically insulating material, which has aluminum oxide, for instance, and insulates the first metallic material 26 from the second metallic material 28. The further embodiment of the rotor 6 in FIG. 6 corresponds to that in FIG. 4.

[0047] FIG. 7 shows a schematic representation of a first method for producing a rotor 6. The coating 14 of the rotor 6 is sprayed using cold gas spraying by, by way of example, two spraying devices 30, 32 onto the substantially cylindrical outer surface 24 of the shaft body 12, wherein the spraying devices are arranged axially one behind the other and/or adjacent to one another h the peripheral direction.

[0048] The spraying devices 30, 32 are operated simultaneously or alternately. The metallic materials 26, 28 of the coating 14 are sprayed in a rolling manner onto the shaft body 12, which means that the shaft body 12 is rotated about its axis of rotation 4, while the spraying devices 30, 32 are moved parallel to the axis of rotation 4. Since the spraying devices 30, 32 are not moved in the peripheral direction, it is ensured that the solid body particle strikes the outer surface 24 of the shaft body 12 at a constant angle of 80° to 110°.

[0049] The spraying of the metallic materials 26, 28 in a rolling manner takes place alternately, which means that the shaft body 12 is at a standstill while the spraying devices 30, 32 are moved in the axial direction and in the process the solid body particles are sprayed. The shaft body 12 is then rotated about a small step angle, while the spraying process is interrupted. The solid body particles are then applied again in an immediately adjacent path which runs parallel to the axis of rotation, while the shaft body 12 is at a standstill. The further embodiment of the rotor 6 in FIG. 7 corresponds to that in FIG. 3.

[0050] FIG. 8 shows a schematic representation of a second method for producing a rotor 6. The spraying of the metallic materials 26, 28 in a rolling manner is carried out on an evolvent path, which means that, contrary to the alternating spraying, while the spraying devices 30, 32 are moved in the axial direction and in the process the solid body particles are sprayed, the shaft body 12 likewise moves. In order to achieve reproducible results, the movements of the spraying devices 30, 32 and the rotational movement of the shaft body 12 must be synchronized. The further embodiment of the rotor 6 in FIG. 8 corresponds to that in FIG. 7.

[0051] In summary, the invention relates to a method for producing a rotor 6 for an electric rotating machine 2 having at least one shaft body 12. In order to specify a production method, which, compared with the prior art, is simpler and more cost-effective, it is proposed that a coating 14 made from at least one first metallic material 26 and a second metallic material 28, which is different from the first metallic material 26, is sprayed onto at least part of a substantially cylindrical outer surface 24 of the shaft body 12 by means of a thermal spraying method, wherein at least one part of a magnet pole-generating element is embodied by means of the coating 14.