ROTOR FOR AN ELECTRICAL MACHINE, ELECTRICAL MACHINE FOR A VEHICLE, AND METHOD FOR MANUFACTURING A ROTOR FOR AN ELECTRICAL MACHINE

Abstract

Rotor (1) for an electrical machine (101), having: a rotor core (2) with a plurality of radially outwardly extending rotor legs (3); a number of exciter windings (4) corresponding to the number of rotor legs (3), each wound around one of the rotor legs (3); and a pot-like end cap (5) which covers the end faces of the exciter windings (4) and has a passage opening (6) for a shaft (7), wherein the exciter windings (4) and the end cap (5) delimit intermediate spaces (16), in each of which a casting compound (17) is arranged.

Claims

1. A rotor for an electrical machine, comprising: a rotor core with a plurality of radially outwardly extending rotor legs; a number of exciter windings corresponding to the number of rotor legs, each wound around one of the rotor legs; and a pot-like end cap which covers the end faces of the exciter windings and has a passage opening for a shaft, wherein the exciter windings and the end cap delimit intermediate spaces, in each of which a casting compound is arranged.

2. The rotor according to claim 1, wherein: a respective exciter winding axially inwardly delimits one of the intermediate spaces, and/or the end cap axially outwardly delimits a respective intermediate space, and/or the end cap radially outwardly delimits a respective intermediate space, and/or the shaft radially inwardly delimits a respective intermediate space.

3. The rotor according to claim 1, wherein the casting compound thermally conductively contacts the shaft.

4. The rotor according to claim 1, wherein the end cap on the rotor core side has a surface contour which delimits a respective intermediate space in the circumferential direction.

5. The rotor according to claim 1, further comprising: a terminating device which is arranged on the end face of the rotor core and comprises terminating elements which each extend between the rotor leg and the exciter winding.

6. The rotor according to claim 5, wherein the end cap radially outwardly overlaps the terminating device.

7. The rotor according to claim 5, wherein the end cap is attached by latching elements to at least some of the terminating elements.

8. The rotor according to claim 5, wherein the terminating device has a surface structure which is formed by axial depressions, wherein the casting compound extends into the depressions.

9. The rotor according to claim 8, wherein the surface structure is formed by a perforation and/or a groove running in the circumferential direction.

10. The rotor according to claim 8, wherein the terminating device has an annular body which surrounds the passage opening for the shaft, and from which the terminating elements extend radially outwardly, wherein the surface structure is formed in the annular body.

11. The rotor according to claim 1, further comprising a number of separating elements corresponding to the number of rotor legs, said separating elements being arranged between respective adjacent pairs of rotor legs.

12. The rotor according to claim 11, wherein a respective separating element unilaterally delimits two adjacent intermediate spaces in the circumferential direction and/or rests on the end cap.

13. The rotor according to claim 1, wherein the casting compound is a hardened heat-conductive paste.

14. An electrical machine for a vehicle, comprising: a stator; and a rotor according to claim 1, which is rotatably mounted inside the stator.

15. A method for manufacturing a rotor for an electrical machine according to claim 1, the method comprising of: provision of a rotor core with a plurality of radially outwardly extending rotor legs, around which is wound a number of exciter windings corresponding to the number of rotor legs, and a pot-like end cap which covers the end faces of the exciter windings and has a passage opening for a shaft, wherein the exciter windings and the end cap delimit intermediate spaces; filling of the intermediate spaces with a casting compound which is a heat-conductive paste and/or has a dynamic viscosity of at least 1 Pa.Math.s; and hardening of the casting compound.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0029] Further advantages and details of the present invention emerge from the exemplary embodiments described below and on the basis of the drawings. These are schematic illustrations and show:

[0030] FIG. 1 a sectional view of a first exemplary embodiment of the rotor according to the invention;

[0031] FIG. 2 a perspective, detail depiction of the rotor core, the exciter windings, the terminating device and the separating elements of the first exemplary embodiment;

[0032] FIG. 3 a sectional, detail view of the first exemplary embodiment in the region of one of the intermediate spaces;

[0033] FIG. 4 a sectional, detail view of a second exemplary embodiment of the rotor according to the invention in the region of one of the intermediate spaces; and

[0034] FIG. 5 a basic diagram of a vehicle with an exemplary embodiment of the electrical machine according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0035] FIG. 1 shows a sectional view of a first exemplary embodiment of a rotor 1.

[0036] The rotor 1 has a rotor core 2 with a plurality of radially outwardly extending rotor legs 3 which may be formed as a plate packet. In the present exemplary embodiment, as an example, eight rotor legs 3 are provided. In addition, the rotor 1 has a number of exciter windings 4 corresponding to the number of rotor legs 3, each wound around the rotor legs 3.

[0037] Also, the rotor 1 comprises a pot-like end cap 5 which covers the end faces of the exciter windings 4 and has a passage opening 6 for a shaft 7. The end cap 5 may for this have a base surface 8 in which the passage opening 6 is formed, and an axially inwardly extending collar 9 which is arranged on the radially outer edge of the base surface 8 and extends completely about the rotational axis 10 of the rotor 1 in the circumferential direction.

[0038] FIG. 2 is a perspective illustration of individual components of the rotor 1 according to the first exemplary embodiment.

[0039] The rotor 1 may furthermore comprise a terminating device 11 which has an annular body 12 through which the shaft 7 extends, and several terminating elements 13 protruding radially outwardly from the body 12. The terminating elements 13 in particular extend between a respective rotor leg 3 and the exciter winding 4 wound around this.

[0040] Optionally, the rotor 1 has eight separating elements 14, two of which are not shown in FIG. 2. The separating elements 14 may be wedge-shaped and arranged between a respective pair of adjacent pair of rotor legs 3. The separating elements 14 here preferably extend completely along the rotor legs 3 in the axial direction, and are furthermore formed axially slightly wider than the exciter windings 4.

[0041] Finally, FIG. 2 also shows preferably provided pole shoes 15 of a respective rotor leg 3, which define the outer periphery of the rotor 1.

[0042] FIG. 3 is a sectional, detail view of the first exemplary embodiment in the region of an intermediate space 16 between a respective exciter winding 4 and the end cap 5.

[0043] The intermediate space 16 is delimited axially inwardly by the exciter winding 4 and the terminating element 13, axially outwardly by the base surface 8 of the end cap 5, radially outwardly by the collar 9 of the end cap 5, and radially inwardly by the shaft 7. A casting compound 17, formed from a hardened heat-conductive paste, is arranged in the intermediate space 16. The heat-conductive paste is preferably semi-fluid during manufacture of the rotor 1 so that it can be easily introduced into the intermediate space 16. It can then harden into the casting compound 17 illustrated. The casting compound 17 mechanically stabilises the end faces of the exciter windings 4, known as the winding heads. Also, the casting compound 17 forms a heat-transmission path from the winding heads to the shaft 7, and a further heat-transmission path from the winding heads via the end cap 5 to the shaft 7, which improves the heat dissipation of the exciter windings 4 and the rotor core 2.

[0044] In the circumferential direction, the intermediate spaces 16 are delimited by an axially inwardly pointing surface contour (not shown) of the end cap 5. The separating elements 14 lie on the surface contour, and thereby also each unilaterally delimit two intermediate spaces 16 in the circumferential direction.

[0045] As furthermore evident from FIG. 3, the end cap 5 or its collar 9 may rest in particular radially outwardly on and be attached to the protrusion 18 of the terminating element 13. In addition, a depression 19 may be formed in the annular body 12, for example in the form of bores and/or an annular groove, into which the casting compound 17 also extends in order to increase the effective heat exchange area.

[0046] FIG. 4 is a sectional, detail view of a second exemplary embodiment of the rotor 1 in the region of the intermediate space 16 between a respective exciter winding 4 and the end cap 5. Unless stipulated otherwise, all statements relating to the first exemplary embodiment may be transferred to this exemplary embodiment. The same or equivalent components carry identical reference signs.

[0047] The second exemplary embodiment is in particular distinguished in that the end plate 5 is secured to the terminating device 15 by latching elements 20. For this, opposing complementary latching lugs 21 may be formed on the collar 9 and on the protrusion 18, and hold the end plate 5 by force fit on the respective terminating element 13.

[0048] FIG. 5 is a basic diagram of a vehicle 100 which comprises an electrical machine 101 configured for driving the vehicle 100. The electrical machine 101 comprises a stator 102 and a rotor 1 according to one of the above-described exemplary embodiments, which is rotatably mounted inside the stator. The electrical machine 101 may be configured as an electric motor and as a separately excited synchronous machine.