Component for a Rotor of an Electric Machine Having a Slot Insulation Element and Heat Sink

Abstract

The invention relates to a component (30) for lining a slot (7) that is formed between two poles of a rotor core (2) of a rotor (1) and that extends axially between two end faces (9) of the rotor core (2), having a slot insulation element (15) for electrically insulating winding sections, arranged in the slot (7), of windings (45) of the rotor (1) from the rotor core (2), which slot insulation element has two side regions (21) for resting on slot edges (16) of the slot (7) and a base region (22) to be arranged so as to overlap with a slot base (17) of the slot (7), wherein a bottom (26), facing the slot base (17), of the base region (22) of the slot insulation element (15) has an axially extending notch (27) and the component (30) has a heat sink (29) having at least one cooling fluid-carrying cooling channel (33) for cooling the winding sections arranged in the slot insulation element (15), which heat sink is arranged in the notch (27) of the slot insulation element (15) so as to be arranged on the slot base (17) and is mechanically connected to the slot insulation element (15). (FIG. 8)

Claims

1-13. (canceled)

14. A component for lining a slot that is formed between two poles of a rotor core of a rotor and that extends axially between two end faces of the rotor core, the component comprising: a slot insulation element configured to electrically insulate winding sections of windings of the rotor from the rotor core, the electrically insulated winding sections being arranged in the slot, the slot insulation element comprising: two side areas configured to contact with slot flanks of the slot; and a base area configured in an overlapping arrangement with a slot base of the slot, wherein an underside of the base area of the slot insulation element facing the slot base comprises an axially extending notch, and a heat sink with at least one cooling fluid-carrying cooling duct configured to cool the winding sections that are arranged in the slot insulation element, the heat sink being arranged in the notch of the slot insulation element for arrangement on the slot base and being mechanically connected to the slot insulation element.

15. The component according to claim 14, wherein the at least one cooling duct is formed as a recess in a surface of the heat sink facing the notch, which is closed off by the underside of the base area.

16. The component according to claim 14, wherein the slot insulation element is a dimensionally stable finished part formed of a synthetic material that is welded to the heat sink.

17. The component according to claim 14, wherein the component is configured for arrangement in the slot defined between salient poles of a salient rotor core, and by pole teeth and pole shoes of the salient poles and a yoke of the salient pole rotor core, wherein the side areas of the slot insulation element are configured to contact the slot flanks formed by pole tooth flanks of the pole teeth and pole shoe undersides of the pole shoes, and wherein each has a first surface section configured to contact the respective pole tooth flank and a second surface section angled with respect to the first surface section and configured to contact the respective pole shoe underside, wherein a the base area has a saddle roof shape and is configured for overlapping arrangement with an outer side area of the yoke forming the slot base, and has two third surface sections that are angled towards one another and form the notch having a triangular profile shape, so that by respectively one of the first surface sections, one of the second surface sections, and one of the third surface sections, in each case, a rectangular profile-shaped slot area of the slot is formed for receiving the winding sections of a respective winding held by the salient pole adjacent to the slot area, and wherein the heat sink is of a triangular prismatic design and has three lateral surfaces that are angled towards one another for contact with the third surface sections of the slot insulation element and the outer side area of the yoke.

18. The component according to claim 17, wherein the at least one cooling duct is designed as a U-shaped recess, wherein a first recess section extends axially in a first of the lateral surfaces and forms a forward flow for the cooling fluid, wherein a second recess section extends axially in a second of the lateral surfaces and forms a return flow for the cooling fluid, and wherein a third recess section connects the axial recess sections and forms a deflection section for the cooling fluid.

19. The component according to claim 18, wherein the heat sink has a connection piece that has an inlet for the cooling fluid connected to the forward flow and an outlet for the cooling fluid connected to the return flow.

20. An assembly for arrangement on a rotor core of a rotor of an electric machine, comprising: a plurality of the components according to claim 14 corresponding to a number of slots; and a fluid conduit device arranged on an end face of the rotor core, which is fluidically coupled to the cooling ducts of the heat sinks for distributing the cooling fluid to the plurality of components and for collecting the cooling fluid from the plurality of components.

21. The assembly according to claim 20, wherein the fluid conduit device comprises: a collecting ring configured to couple to an outlet opening of a cooling fluid-carrying rotor shaft of the rotor, which is configured to receive the cooling fluid from the rotor shaft; a distributor duct system that is fluidically coupled to the collecting ring and, for distributing the cooling fluid to the heat sinks, to forward flows of the cooling ducts of the plurality of components; a collector duct system that is fluidically coupled to return flows of the cooling ducts of the plurality of components configured to receive the cooling fluid from the heat sinks; and at least one separation opening that is fluidically coupled to the collector duct system and is configured to separate the cooling fluid collected from the return flows of the cooling ducts into an environment of the rotor.

22. The assembly according to claim 21, wherein the fluid conduit device is configured as a fluid conducting body that has a number of duct branches corresponding to a number of poles, wherein, in each case, one duct branch is fluidically coupled to two adjacent components of the plurality of components, and wherein first branches of the duct branches form distributor ducts of the distributor duct system, and second branches of the duct branches form collector ducts of the collector duct system.

23. The assembly according to claim 22, wherein the duct branches each have an axial branch section and two branch sections extending at an end side and issuing from the associated axial branch section, wherein the axial branch sections of the first duct branches are fluidically coupled to the collecting ring, and wherein the axial branch sections of the second duct branches are fluidically coupled to respectively a separation opening.

24. The assembly according to claim 23, wherein the plurality of components are arranged axially protruding on an underside of the fluid conducting body overlapping with ends of the branch sections extending on the end side, wherein the ends have axial through-going openings, into which inlets of the heat sinks are inserted for coupling the distributor ducts to the forward flows of the cooling ducts and outlets of the heat sinks are inserted for coupling the collector ducts to the return flows.

25. A rotor for an electric machine comprising: a rotor core; windings arranged in slots of the rotor core; and an assembly according to claim 20, wherein the plurality of components are arranged in the slots of the rotor core between axial winding sections of the windings, and wherein the fluid conduit device is arranged on one of the end faces of the rotor core.

26. An electric machine for a motor vehicle, comprising: a stator; and the rotor according to claim 25 that is mounted so as to be configured to rotate with respect to the stator.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 shows a perspective view of a rotor for an electric machine;

[0024] FIG. 2 shows a perspective view of a lamination stack of the rotor, the lamination stack being fitted with star discs;

[0025] FIG. 3 shows a perspective view of a slot insulation component of the rotor;

[0026] FIG. 4 shows a perspective view of a heat sink of the rotor;

[0027] FIG. 5 shows a first perspective view of a component formed by the slot insulation component and the heat sink;

[0028] FIG. 6 shows a second perspective view of a component that is formed by the slot insulation component and the heat sink;

[0029] FIG. 7 shows a third perspective view of a component that is formed by the slot insulation component and the heat sink;

[0030] FIG. 8 shows a perspective view of the rotor core that is fitted with the star discs and the components;

[0031] FIG. 9 shows a perspective view of the rotor core that is fitted with the star discs and an assembly that comprises the components;

[0032] FIG. 10 shows a first longitudinal sectional view of the rotor;

[0033] FIG. 11 shows a second longitudinal sectional view through the rotor; and

[0034] FIG. 12 shows a cross-sectional view through the rotor in the area of a fluid conducting device of the assembly.

DETAILED DESCRIPTION OF THE DRAWINGS

[0035] In the figures, identical and functionally identical elements are labeled with the same reference signs.

[0036] FIG. 1 shows a perspective view of a rotor 1 for an electric motor of a motor vehicle. The rotor 1 has a rotor core 2, also shown in FIG. 2, which is manufactured here in a salient-pole design. The rotor core 2 can be a lamination stack, for example. The rotor core 2 has a yoke 3 and salient poles 4 which project radially from the yoke 3 and are arranged at a distance from each other in the circumferential direction. Each salient pole 4 has a pole tooth 5 and a pole shoe 6. A slot 7 or pole gap is formed in each case between two adjacent salient poles 4, wherein the slots 7 are designed to receive axial winding sections of windings, not shown here, of the rotor 1, wound around the respective adjacent pole teeth 5. The slots 7 are each closed with a slot closing wedge 8.

[0037] End-side winding sections are guided on axially opposing end faces 9 of the rotor core 2 via electrically insulating star discs 10 arranged there. For this purpose, the star discs 10 have, for example, guide slots 11 to provide a transition between the axial and end-side winding sections. The end-side winding sections form winding heads on the end faces 9, the winding heads each being supported against centrifugal forces by a support ring 12 arranged in each case on the respective star disc 10. The support rings 12 and the star discs 10 are mechanically connected, for example pressed together. In addition, the rotor 1 has a rotor shaft 13 which passes axially through the rotor core 2 and can have a toothing 14 for connection to a gearbox input shaft. The rotor shaft 13 is designed in particular to conduct a cooling fluid.

[0038] In order to electrically insulate the axial winding sections from the rotor core 2, slot insulation elements 15 are arranged in the slots 7, of which one slot insulation element 15 is shown in perspective view in FIG. 3. The slot insulation element 15 is in particular an elongated finished part made of a synthetic material, which can be inserted, for example pushed in, into a respective slot 7 in order to provide lining. Each slot 7 has two slot flanks 16 and a slot base 17. A slot flank 16 is formed here by a pole tooth flank 18 of the pole tooth 5 adjacent to the slot 7 and a pole shoe underside 19 of the pole shoe 6 adjacent to the slot 7. A slot base 17 is formed by an outer side area 20 of the yoke 3 adjacent to the slot 7. In order to line the slot 7, the slot insulating element 15 has two side areas 21 for contact with the slot flanks 16, and a base area 22 for overlapping arrangement with the slot base 17.

[0039] The side areas 21 each have a first surface section 23 for contact with a respective pole tooth flank 18 and a second surface section 24 angled, in particular at right angles, to the first surface section 23 for contact with a respective pole shoe underside 19. The base area 22 is saddle roof-shaped and has two third surface sections 25 which are angled towards each other and form a triangular notch 27 on an underside 26 of the base area 22. Due to this arrangement of the surface sections 23, 24, 25 relative to one another, a rectangular profile-shaped slot area 28 is formed in the slot 7 by a first surface section 23, a second surface section 24 and a third surface section 25 respectively. Each slot 7 therefore has two rectangular profile-shaped slot areas 28, wherein a stack with axial winding sections can be arranged in each slot area 28 with a precise fit.

[0040] A heat sink 29 is arranged in the notch 27 of the slot insulation element 15, it is shown in a perspective view in FIG. 4 and is designed to cool the winding sections arranged in the respective slot 27. This forms the component 30 shown in perspective in FIG. 5. FIG. 6 shows the component 30 from an oblique perspective looking at the component 30 from below. FIG. 7 shows the component 30 in a top view. FIG. 8 shows the rotor core 2 fitted with the components 30. The heat sink 29 is of a triangular-prismatic design and has three lateral surfaces 31a, 31b, 31c arranged in a triangle. Upper lateral surfaces 31a, 31b are arranged adjacent to the third surface sections 25 of the slot insulation component 15. A lower lateral surface 31c is arranged adjacent to the slot base 17, in this case the outer side area 20 of the yoke 3. A shape of the lower lateral surface 31c corresponds to a contour of the outer side area 20 of the yoke 3.

[0041] The upper lateral surfaces 31a, 31b facing the notch 27 have multiple axially extending U-shaped recesses 32, which are milled into the upper lateral surfaces 31a, 31b, for example, and form cooling ducts 33 for conducting a cooling fluid. These cooling ducts 33 are sealed off from the outside when the heat sink 29 is joined, for example welded, to the slot insulation component 15 in that the third surface sections 25 covers the recesses 32. The component 30 arranged in the slot 7 is therefore designed to conduct a cooling fluid through the slot 7 and thereby cool the axial winding sections.

[0042] One end of the cooling body 29 is designed here as a connection piece 34 having a nozzle-shaped inlet 35 and a nozzle-shaped outlet 36. The inlet 35 is fluidically connected to recess sections of the recesses 32 of the one upper lateral surface 31a, which form forward flows 37 of the cooling ducts 33, and the outlet 36 is connected to recess sections of the recesses 32 of the other upper lateral surface 31b, which form return flows 38 of the cooling ducts 33. The connection piece 34 is angled and thus extends in a radial direction in some areas over one of the end faces 9 of the rotor core 2. For example, one of the star discs 10 has a receptacle 39 for the connection pieces 34 in the area of each slot 7, so that the connection pieces 34 are recessed in some areas in the star disc 10 and are connected in a positive-locking manner to the star disc 10 at least in the circumferential direction.

[0043] In order to distribute the cooling fluid to the components 30 and to collect the cooling fluid, which is conducted from the components 30 through the slots 7, from the components 30, a fluid conduit device 40 is provided, which is fluidically and mechanically coupled to the components 30, forming an assembly 41. FIG. 9 shows the rotor core 2 that is fitted with the star discs 10 and the assembly 41. The fluid conduit device 40 is attached to one of the star discs 10 and thus arranged on one of the end faces 9 of the rotor core 2. The fluid conduit device 40 is designed as a one-piece fluid conducting body 42, which has a collecting ring 43, which is coupled to the forward flows 37 of the cooling ducts 33 of the components 30 and via which the cooling fluid can be supplied to the cooling ducts 33. FIG. 10 shows a longitudinal section through the rotor 1 in the area of an outlet opening 44 to the collecting ring 43. FIG. 10 also shows the windings 45 of the rotor 1 wound around the salient poles 4. The outlet opening 44 is formed, for example, as a radial bore in the rotor shaft 13 that carries the cooling fluid. For this purpose, the collecting ring 43 is arranged at the axial height on the rotor shaft 13 at which the outlet openings 44 are located. The fluid conduit device 40 also has a distributor duct system 46, which is coupled to the collecting ring 43 and the inlets 35 of the connecting pieces 34. In this way, the cooling fluid from the rotor shaft 13 can be fed into the collecting ring 43 via the distributor duct system 46 to the forward flows 37 of the cooling ducts 33 of the components 30.

[0044] The fluid conduit device 40 also has a collector duct system 47, which is coupled to the outlets 36 of the connecting pieces 34 of the components 30 and via which the cooling fluid collected from the components 30 can be conducted to separation openings 48 of the fluid conduit device 38. The cooling fluid can be separated into an environment of the rotor 1 via the separation openings 48. FIG. 11 shows a longitudinal section through the rotor 1 in the area of one of the separation openings 48.

[0045] The distributor duct system 46 has multiple separate distributor ducts 49, wherein respectively one distributor duct 49 is designed to distribute the cooling fluid to two adjacent components 30 and thus to two adjacent slots 7. The collector duct system 47 also has multiple separate collector ducts 50, wherein one collector duct 50 is designed to receive the cooling fluid from two adjacent components 30 and thus from two adjacent slots 7. The distributor ducts 49 and the collector ducts 50 are arranged alternately to each other in the circumferential direction. The components 30 are therefore arranged in such a way that in the case of two adjacent components 30, cooling duct sections of the same type, i.e. either the forward flows 37 or the return flows 38, are arranged adjacent to each other. The cooling duct sections arranged on both sides of a salient pole 4 therefore flow through the respective slots 7 in the same direction.

[0046] The distributor ducts 49 and the collector ducts 50 are designed as duct branches 51, 52. Axial branch sections 51a of the first duct branches 51, which form the distributor ducts 49, are coupled to the collecting ring 43. Axial branch sections 52a of the duct branches 52 which form the collector ducts 50 are coupled to the separation openings 48.

[0047] End-side branch sections 51b of the first duct branches 51, which are shown in the cross-sectional view through the rotor 1 in FIG. 12, are fluidically coupled to the forward flows 37 of the heat sinks 30. End-side branch sections 52b of the second duct branches 52 are fluidically coupled to the forward flows 38 of the heat sinks 30. For this purpose, the ends of the end-side branches 51b, 52b each have an axial through-going opening 53, into which the inlets 35 are inserted in the case of the first duct branch sections 51 and into which the outlets 36 are inserted in the case of the second duct branches 52. In order to distribute the cooling fluid to the cooling ducts 33, the cooling fluid from the collecting ring 43 enters the axial branch sections 51a of the first duct branches 51, is conducted into the end-side branch sections 51b and enters the forward flows 37 at their ends via the respective through-going opening 53. In order to remove the cooling fluid from the cooling ducts 33, the cooling fluid from the return flows 38 enters the end-side branch sections 52b of the second duct branches 52 via the respective through openings 53, is conducted into the axial branch sections 52a and exits into the environment via the separation openings 48.