Rotor of an electric machine

Abstract

The invention relates to a rotor (1) of an electric machine, in particular an electrically excited synchronous machine, comprising a rotor shaft (3) which can be rotated about a rotor axis (2), in particular which is a hollow shaft, comprising multiple separate salient poles (4) arranged around a circumferential direction of the rotor (1), which are anchored in a rotor yoke (5), in particular interlockingly, characterised in that the rotor yoke (5) is formed in the rotor shaft (3).

Description

[0001] Description

[0002] title

[0003] Rotor of an electrical machine

[0004] State of the art

[0005] The invention is based on a rotor of an electrical machine according to the preamble of the main claim.

[0006] A rotor of an electrical machine is already known from JP54134304 A2, having a rotor shaft rotatable about a rotor axis, with a plurality of separate salient poles arranged along a circumferential direction of the rotor, which are anchored in anchoring slots of the rotor.

[0007] The rotor's anchoring slots are formed in a support body arranged on the rotor shaft, which forms the yoke and is designed as a laminated core. A disadvantage is that the laminated or laminated core yoke has low speed stability. Furthermore, the support body requires a large amount of radial space.

[0008] Advantages of the invention

[0009] The rotor of an electrical machine according to the invention with the characterizing features of the main claim has the advantage that the speed stability of the rotor is increased by the rotor yoke being formed in the rotor shaft.

[0010] The higher speed stability results from the fact that the rotor shaft is made of a non-laminated, i.e., solid, material. The non-laminated rotor shaft as a rotor yoke also enables easier joining of the salient poles than if both joining partners were laminated. By integrating the prior art support body into the rotor shaft, the complex step of attaching the support body to the rotor shaft, in particular by pressing it on, is eliminated. The rotor shaft according to the invention is thus designed without a hub. This reduces manufacturing costs. The measures listed in the subclaims enable advantageous refinements and improvements to the rotor specified in the main claim.

[0011] According to an advantageous embodiment, the rotor shaft is a non-laminated body, and the salient poles are each formed as laminated pole bodies. This pairing results in flatter contact surfaces in the rotor shaft, allowing the salient poles to be aligned more precisely during assembly. Furthermore, there is less variation in speed stability.

[0012] It is particularly advantageous if the salient poles are anchored to an anchoring shoulder of the rotor shaft, which is formed integrally with the rotor shaft and is, in particular, cylindrical. In this way, the prior art rotor carrier is integrated integrally into the rotor shaft.

[0013] It is further advantageous if anchoring grooves are formed on the anchoring shoulder of the rotor shaft according to the two exemplary embodiments, into each of which a protruding pole armature of one of the salient poles extends. Alternatively, anchoring projections can be formed on the anchoring shoulder of the rotor shaft, each of which extends into a pole recess of one of the salient poles.

[0014] It is very advantageous if the pole anchor or the pole recess of the salient poles each has an anchoring profile, particularly one that is fir-tree-shaped, tree-shaped, T-shaped, dovetail-shaped, triangular, rectangular, or square-shaped. This allows for a very firm anchoring of the salient poles.

[0015] It is also advantageous if the anchoring grooves or the anchoring projections of the rotor shaft each have an anchoring counter-profile for positive interaction with the anchoring profile of the salient poles. In this way, a very strong anchoring of the salient poles can be achieved. Furthermore, it is advantageous if, according to the two exemplary embodiments, the anchoring grooves of the rotor shaft each have two groove flanks, wherein flank teeth are formed on the groove flanks of the respective anchoring groove, which extend in the axial direction with respect to the rotor axis and form undercuts of the anchoring counter-profile and which are in particular triangular or sawtooth-shaped. In this way, a very deep radial anchoring of the salient poles in the rotor shaft and thus a very high speed stability can be achieved.

[0016] It is also advantageous if several flank teeth are arranged one behind the other in a radial direction relative to the rotor axis per groove flank of the respective anchoring groove of the rotor shaft. This can further increase the speed stability.

[0017] It is advantageous if the anchoring shoulder of the rotor shaft is a shaft shoulder with the greatest radial extent and that two shaft shoulders adjacent to the anchoring shoulder with a radially smaller extent are provided, wherein the adjacent shaft shoulders according to a second embodiment have run-out grooves that lead into the anchoring grooves of the anchoring shoulder and in particular have a greater width than the anchoring grooves. In this way, a groove base of the anchoring grooves can be placed radially even deeper into the rotor shaft, so that the speed stability can be increased even further by a higher number of flank teeth. In addition, the run-out grooves of the rotor shaft act as a joining aid during the axial insertion of the pole armatures into the anchoring grooves of the rotor shaft.

[0018] It is also advantageous if the anchoring shoulder of the rotor shaft is longer in the axial direction relative to the rotor axis than the salient poles, in particular by more than half the sheet thickness of a lamination of one of the salient poles. This ensures that no individual lamination of the respective salient pole lies partially or completely outside the respective anchoring groove when viewed in the axial direction, thus ensuring that each lamination of the individual salient poles is anchored directly to the rotor shaft and not indirectly via adjacent laminations of the respective salient pole. The invention further relates to an electrical machine with a rotor according to the invention.

[0019] drawing

[0020] An embodiment of the invention is shown in simplified form in the drawing and explained in more detail in the following description

[0021] Fig.1 shows in section a rotor according to the invention according to a first embodiment, Fig.2 shows a rotor shaft according to the invention of the rotor according to Fig.1, Fig.3 shows a rotor according to the invention according to a second embodiment and Fig.4 shows the rotor shaft according to the invention of the rotor according to Fig.3.

[0022] Description of the embodiments

[0023] Fig. 1 shows a section through a rotor according to the invention according to a first embodiment. Fig. 2 shows a rotor shaft according to the invention of the rotor according to Fig. 1.

[0024] The rotor 1 according to the invention of an electrical machine, in particular an electrically excited synchronous machine, comprises a rotor shaft 3, which is rotatable about a rotor axis 2 and is in particular a hollow shaft, and a plurality of separate salient poles 4 arranged along a circumferential direction of the rotor 1 and anchored, in particular in a form-fitting manner, in a rotor yoke 5. A rotor winding 9 is provided between the salient poles 4, which comprises, for example, individual coils, each of which extends around one of the salient poles 4.

[0025] According to the invention, the rotor yoke 5 is formed in the rotor shaft 3. The rotor shaft 3 is a non-laminated body, while the salient poles 4 are each formed as laminated pole bodies. The laminated pole bodies of the salient poles 4 are thus each designed as a laminated core.

[0026] The salient poles 4 of the rotor 1 are anchored to an anchoring shoulder 6 of the rotor shaft 1. The anchoring shoulder 6 of the rotor shaft 1 is formed integrally on the rotor shaft 1 and is, in particular, cylindrical.

[0027] According to the two exemplary embodiments, anchoring grooves 7 are formed on the anchoring shoulder 6 of the rotor shaft 1, into each of which a radially projecting pole armature 8 of one of the salient poles 4 projects. The pole armature 8 of the salient pole 4 extends in the axial direction, for example, over the entire length of the salient pole 4 and is, for example, part of the laminated core of the salient pole 4.

[0028] Alternatively, anchoring projections can be formed on the anchoring shoulder 6 of the rotor shaft 1 in a manner not shown, each extending into a pole recess of one of the salient poles 4. The pole armature 8 or the pole recess of the salient poles 4 each has an anchoring profile 10, which is, for example, fir-tree-shaped, tree-shaped, T-shaped, dovetail-shaped, triangular, rectangular, or square-shaped. The anchoring grooves 7 or the anchoring projections of the rotor shaft 1 each have a corresponding anchoring counter-profile 11 for positive engagement with the anchoring profile 10 of the salient poles 4.

[0029] The anchoring grooves 7 of the rotor shaft 1 each have two groove flanks 7.1 and a groove base 7.2 and are milled, for example. Triangular or sawtooth-shaped flank teeth 12, for example, are formed on the groove flanks 7.1 of the respective anchoring groove 7. These flank teeth extend in the axial direction relative to the rotor axis 2 and form undercuts of the anchoring counter-profile 11. Accordingly, the flanks of the anchoring profile 10 of the pole anchors 8 also have corresponding flank teeth 12.

[0030] For each groove flank 7.1 of the respective anchoring groove 7, several flank teeth 12 are arranged one behind the other in the radial direction relative to the rotor axis 2. The groove base of the anchoring grooves 7 lies, for example, at a constant radial level or at a constant radius along the axial extent.

[0031] The anchoring shoulder 6 of the rotor shaft 1 is a shaft shoulder with the greatest radial extension. Two shaft shoulders 16 adjacent to the anchoring shoulder 6 are provided with a smaller radial extension, so that the anchoring shoulder 6 lies between the two adjacent shaft shoulders 16. The rotor shaft 1 also comprises two shaft ends 3e, between which the anchoring shoulder 6 and the two adjacent shaft shoulders 16 are arranged.

[0032] The anchoring shoulder 6 of the rotor shaft 1 can - as shown in Fig.3 - be longer in the axial direction with respect to the rotor axis 2 than the salient poles 4, by more than half a sheet thickness, in particular by one or more sheet thicknesses, of a lamination of one of the salient poles 4.

[0033] Fig. 3 shows a rotor according to the invention according to a second embodiment. Fig. 4 shows the rotor shaft according to the invention of the rotor according to Fig. 3.

[0034] The second embodiment differs from the first embodiment only in that the adjacent shaft shoulders 16 have runout grooves 17 that lead into the anchoring grooves 7 of the anchoring shoulder 6 and that, for example, to facilitate axial insertion, have a greater width (measured in the circumferential direction) than the anchoring grooves 7. The runout grooves 17 can narrow continuously in the circumferential direction toward the anchoring grooves 7. Alternatively or additionally, an insertion bevel can be provided at the transition from the respective runout groove 17 to the respective anchoring groove 7. The runout grooves 17 are also milled, for example.

[0035] The groove base of the anchoring grooves 7 and the groove base of the runout grooves 17 are located, for example, at the same radial level or at the same radius along the axial extent. The anchoring grooves 7 according to the second embodiment have a greater radial depth than in the first embodiment, so that even more flank teeth 12 are possible per groove flank 7.1, which can further increase the speed stability.

Claims

Claims 1. Rotor (1) of an electrical machine, in particular an electrically excited synchronous machine, with a rotor shaft (3) rotatable about a rotor axis (2), which is in particular a hollow shaft, with several separate salient poles (4) arranged along a circumferential direction of the rotor (1), which are anchored in a rotor yoke (5), in particular positively, characterized in that the rotor yoke (5) is formed in the rotor shaft (3).

2. Rotor according to claim 1, characterized in that the rotor shaft (3) is an unlaminated body and the salient poles(4) are each formed as a laminated pole body.

3. Rotor according to one of the preceding claims, characterized in that the salient poles (4) are anchored to an anchoring shoulder (6) of the rotor shaft (3), which is formed integrally on the rotor shaft (3) and is in particular cylindrical.

4. Rotor according to claim 3, characterized in that anchoring grooves (7) are formed on the anchoring shoulder (6) of the rotor shaft (3), into which a protruding pole anchor (8) of one of the salient poles (4) projects, or that anchoring projections are formed on the anchoring shoulder (6) of the rotor shaft (3), which each extend into a pole recess of one of the salient poles (4).

5. Rotor according to one of the preceding claims, characterized in that the pole armature (8) or the pole recess of the salient poles (4) each has an anchoring profile (10) which is in particular fir tree-shaped, tree-shaped, T-shaped, swallowtail-shaped, triangular, rectangular or square-shaped.

6. Rotor according to claim 5, characterized in that the anchoring grooves (7) or the anchoring projections of the rotor shaft (3) each have an anchoring counter-profile (11) for positive locking interaction with the anchoring profile (10) of the leg poles (4).

7. Rotor according to one of claims 4 to 6, characterized in that the anchoring grooves (7) of the rotor shaft (3) each have two groove flanks (7.1), wherein flank teeth (12) are formed on the groove flanks (7.1) of the respective anchoring groove (7) which extend in the axial direction with respect to the rotor axis (2) and form undercuts of the anchoring counter-profile (11) and which are in particular triangular or sawtooth-shaped.

8. Rotor according to claim 7, characterized in that several flank teeth (12) are arranged one behind the other in a radial direction with respect to the rotor axis (2) for each groove flank (7.1) of the respective anchoring groove (7).

9. Rotor according to one of the preceding claims, characterized in that the anchoring shoulder (6) of the rotor shaft (3) is a shaft shoulder with the greatest radial extent and that two shaft shoulders (16) adjacent to the anchoring shoulder (6) are provided with a radially smaller extent, wherein the adjacent shaft shoulders (16) have run-out grooves (17) which lead into the anchoring grooves (7) of the anchoring shoulder (6) and in particular have a greater width than the anchoring grooves (6).

10. Rotor according to one of the preceding claims, characterized in that the anchoring shoulder (6) of the rotor shaft (3) is longer in the axial direction with respect to the rotor axis (2) than the salient poles (4), in particular by more than half a sheet thickness of a lamella of one of the salient poles (4).

11. Electric machine with a rotor (1) according to one of the preceding claims.

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