ROTOR ASSEMBLY, AND SYNCHRONOUS MACHINE INCLUDING THE ROTOR ASSEMBLY

Abstract

A rotor assembly for an inductively electrically excited synchronous machine may include a hollow shaft, a rotor connected to the hollow shaft, and a secondary-side circuit of an energy transmitter. The secondary-side circuit may be arranged in a rotationally fixed manner in the rotor assembly. The secondary-side circuit may include a rectifier. The rectifier may include a printed circuit board and at least one electrical component part fastened to the printed circuit board and a secondary coil. The rectifier may be aligned transversely to an axis of rotation of the hollow shaft and may be arranged in a rotationally fixed manner in a cavity of the hollow shaft. The rectifier may include a cooling body abutting against the printed circuit board such that the cooling body faces away from the at least one electrical component part and transmits heat.

Claims

1.-11. (canceled)

12. A rotor assembly for an inductively electrically excited synchronous machine, comprising: a hollow shaft rotatable about an axis of rotation; a rotor connected in a rotationally fixed manner to the hollow shaft; a secondary-side circuit of an energy transmitter, the secondary-side circuit arranged in a rotationally fixed manner in the rotor assembly; the secondary-side circuit including a rectifier, the rectifier including a printed circuit board and at least one electrical component part fastened to the printed circuit board and a secondary coil; wherein the rectifier is aligned transversely to the axis of rotation and is arranged in a rotationally fixed manner in a cavity of the hollow shaft; and wherein the rectifier further includes a cooling body of a heat-conducting material, the cooling body abutting against the printed circuit board of the rectifier such that the cooling body faces away from the at least one electrical component part and transmits heat.

13. The rotor assembly according to claim 12, wherein the at least one electrical component part of the rectifier is mechanically supported on the hollow shaft.

14. The rotor assembly according to claim 12, wherein: the hollow shaft is formed of a shaft end and a shaft cover axially closing the shaft end; and the rectifier is firmly connected to at least one of the shaft end and the shaft cover of the hollow shaft.

15. The rotor assembly according to claim 12, wherein the at least one electrical component part of the rectifier is encapsulated with a heat-conducting casting compound.

16. The rotor assembly according to claim 12, wherein the cooling body is electrically insulated from the hollow shaft via a dielectric sheathing.

17. The rotor assembly according to claim 12, wherein the cooling body includes a cooling structure facing away from the printed circuit board.

18. The rotor assembly according to claim 12, wherein the cooling body divides the cavity of the hollow shaft in a fluid-tight manner into (i) a cooling chamber facing away from the printed circuit board and through which at least one of a liquid and a gaseous cooling fluid is flowable and (ii) a transmission chamber receiving the printed circuit board.

19. The rotor assembly according to claim 18, wherein: the hollow shaft has an open axial end, which is open to an outside and extends into the cooling chamber; the cooling fluid is flowable into the cooling chamber of the hollow shaft via the open axial end; the hollow shaft further has at least one opening, which extends radially to the outside from the cooling chamber; and the cooling fluid is flowable out of the cooling chamber of the hollow shaft via the at least one opening.

20. The rotor assembly according to claim 12, wherein the secondary coil of the secondary-side circuit is arranged at least one of in the cavity of the hollow shaft and outside of the cavity of the hollow shaft such that the secondary coil is interactable inductively with a primary-side circuit of the energy transmitter.

21. An inductively electrically excited synchronous machine, comprising: the rotor assembly according to claim 12; a stator assembly including a stator; the rotor assembly received in the stator such that the rotor assembly is rotatable about the axis of rotation; the stator assembly including a primary-side circuit of the energy transmitter; the primary-side circuit arranged in a rotationally fixed manner in the stator assembly; wherein the primary-side circuit includes an inverter and a primary coil; and wherein the primary coil and the secondary coil are arranged such that the primary coil and the secondary coil are interactable with one another inductively.

22. The rotor assembly according to claim 12, wherein the at least one electrical component part of the rectifier is connected to the printed circuit board via a heat-conducting heat conduction pad so as to transmit heat.

23. The rotor assembly according to claim 12, wherein the at least one printed circuit board of the rectifier is connected to the cooling body via a heat-conducting heat conduction pad so as to transmit heat.

24. The rotor assembly according to claim 12, wherein the cooling body is formed from a dielectric material.

25. The rotor assembly according to claim 24, wherein the dielectric material is a composite material.

26. The rotor assembly according to claim 17, wherein the cooling structure includes at least one of (i) at least one cooling rib and (ii) a plurality of cooling pins.

27. A rotor assembly for an inductively electrically excited synchronous machine, comprising: a hollow shaft rotatable about an axis of rotation, the hollow shaft including a cavity; a rotor connected in a rotationally fixed manner to the hollow shaft; a secondary-side circuit of an energy transmitter, the secondary-side circuit connected in a rotationally fixed manner to the hollow shaft, the secondary-side circuit including a rectifier and a secondary coil; wherein the rectifier is aligned transversely to the axis of rotation and divides the cavity of the hollow shaft into (i) a cooling chamber and (ii) a transmission chamber; and wherein the rectifier includes a printed circuit board, at least one electrical component part fastened to a first side of the printed circuit board, and a cooling body abutting an opposite, second side of the printed circuit board.

28. The rotor assembly according to claim 27, further comprising an annular seal extending circumferentially around the axis of rotation, wherein the annular seal is disposed radially between the cooling body and the hollow shaft and, in conjunction with the cooling body, seals the cooling chamber and the transmission chamber from one another in a fluid-tight manner.

29. The rotor assembly according to claim 28, wherein the hollow shaft further includes: a first, open axial end via which cooling fluid is flowable into the cooling chamber; an opposite, second axial end at which the secondary coil is arranged; and a plurality of radial openings via which the cooling fluid is flowable out of the cooling chamber, the plurality of radial openings disposed axially between the rectifier and the open axial end of the hollow shaft.

30. The rotor assembly according to claim 27, wherein the rectifier is oriented within the cavity such that the printed circuit board is disposed in the transmission chamber.

31. The rotor assembly according to claim 27, wherein the secondary coil is arranged in the transmission chamber and is secured to an inner wall of the hollow shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In each case schematically:

[0029] FIG. 1 shows a sectional view of a synchronous machine according to the invention comprising a rotor assembly according to the invention in a first embodiment;

[0030] FIG. 2 shows a sectional view of the synchronous machine according to the invention comprising the rotor assembly according to the invention in a second embodiment;

[0031] FIG. 3 shows a circuit diagram of an energy transmitter in the synchronous machine according to the invention.

DETAILED DESCRIPTION

[0032] FIG. 1 shows a sectional view of an inductively electrically excited synchronous machine 1 according to the invention comprising a rotor assembly 2 according to the invention in a first embodiment. The rotor assembly 2 thereby has a hollow shaft 3 and a rotor 4, wherein the hollow shaft 3 can be rotated about an axis of rotation RA and the rotor 4 is connected in a rotationally fixed manner to the hollow shaft 3. The rotor assembly 2 additionally has a secondary-side circuit 5 of an energy transmitter 6. The secondary-side circuit 5 is connected in a rotationally fixed manner to the rotor assembly 2 or to the hollow shaft 3, respectively, and comprises, see also FIG. 3 with regard to this, a rectifier 7 and a secondary coil 8. The hollow shaft 3 additionally has a cavity 9 and the secondary-side circuit 5, thus the rectifier 7 and a secondary coil 8 here, are arranged in the cavity 9.

[0033] The rectifier 7 thereby has a printed circuit board 10 comprising several electrical component parts 11 and a cooling body 12. The cooling body 12 thereby abuts against the printed circuit board 10 facing away from the electrical component parts 11 and is connected to the printed circuit board 10 so as to transmit heat. Alternatively, the cooling body 12 can abut directly against the electrical component parts 11 so as to transmit heat. The heat from the electrical component parts 11 can thus be dissipated directly to the cooling body 12 and the heat conducting path can thus be shortened. The heat generated in the electrical component parts 11 can thus be dissipated to the cooling body 12 via the printed circuit board 10. The rectifier 7 is aligned transversely to the axis of rotation RA in the cavity 9 and divides the cavity 9 into a cooling chamber 9a and a transmission chamber 9b. The cooling body 12 of the rectifier 7 thereby seals the cooling chamber 9a and the transmission chamber 9b from one another in a fluid-tight manner. For this purpose, an annular sealing element 13, which revolves around the axis of rotation RA, is arranged between the cooling body 12 and the hollow shaft 3. The rectifier 7 is thereby arranged so as to face the cooling chamber 9a with the cooling body 12 and so as to face the transmission chamber 9b with the printed circuit board 10. The secondary coil 8 is secured to an inner wall of the hollow shaft 3 in the transmission chamber 9b.

[0034] A gaseous or liquid cooling fluid can flow through the cooling chamber 9a. The fooling fluid thereby flows into the cooling chamber 9a on an axial end 3a of the hollow shaft 3, which is open to the outside, and out of the cooling chamber 9a via several openings 14 leading radially to the outside. The axial end 3a is thereby arranged so as to be located axially opposite an A-side axial end 3b of the hollow shaft 3. The cooling fluid thereby flows around the cooling body 12, and the heat is dissipated to the cooling fluid by the cooling body 12. Facing the cooling chamber 9a, the cooling body 12 additionally has a cooling structure 15 comprising several cooling ribs 16, or alternatively comprising several cooling pins, which additionally intensify the heat dissipation to the cooling fluid.

[0035] The synchronous machine 1 additionally has a primary-side circuit 17 of the energy transmitter 6 comprising a primary coil 18, see also FIG. 3 with regard to this. The primary coil 18 thereby protrudes into the transmission chamber 9b and into the annular secondary coil 8. An annular gap, which revolves around the axis of rotation RA, is formed between the secondary coil 8 and the primary coil 18, and the secondary coil 8 and the primary coil 18 can interact with one another electromagnetically or so as to transmit energy, respectively, or inductively, respectively, via the gap.

[0036] For the simplified assembly, the hollow shaft 3 is formed in two pieces and has a shaft end 19 and a shaft cover 20. The shaft end 19 thereby encompasses the transmission chamber 9b of the hollow shaft 3 and is assigned to the A-side axial end 3b of the hollow shaft 3. The shaft end 19 and the shaft cover 20 are both formed in a bottle-shaped manner, so that the cavity 9 widens from the axial end 3a to the center and narrows from the center to the A-side axial end 3b. In the first embodiment, the rectifier 7 is arranged in the shaft end 19 and the secondary coil 9 in a narrower region of the cavity 9 or of the transmission chamber 9b, respectively.

[0037] It goes without saying that the synchronous machine 1 also comprises a stator and a housing, which are arranged so as to revolve around the rotor assembly 2 about the axis of rotation RA. The stator and the housing, however, are not shown here for the sake of clarity.

[0038] FIG. 2 shows a sectional view of the synchronous machine 1 according to the invention comprising the rotor assembly 2 according to the invention in a second embodiment. Deviating from the first embodiment in FIG. 1, the shaft end 19 has a larger axial length here compared to the first embodiment in FIG. 1. The secondary coil 8 is thereby arranged in a wider region of the cavity 9 or of the transmission chamber 9b, respectively, and is formed to be axially more compact.

[0039] FIG. 3 shows a circuit diagram of the energy transmitter 6 in the synchronous machine 1 according to the invention. The energy transmitter 6 thereby has the primary-side circuit 17 comprising a connection 21, an inverter 22 and the primary coil 18. The connection 21 can be provided, for example, for interconnecting the energy transmitter 6 to a board electronics of a motor vehicle. The energy transmitter 6 additionally has the secondary-side circuit 5 comprising the secondary coil 8, the rectifier 7 and a rotor winding 23 of the rotor.