Dual-rotor arrangement of an electric machine of a vehicle

Abstract

A dual-rotor arrangement for an electric machine (19) is proposed, comprising a rotor shaft (4) with a first rotor (1) and a second rotor (2) in a housing (3). The rotors (1, 2) are arranged coaxially to the rotor shaft (4). A housing-mounted stator (5) is arranged radially between the first, radially inner rotor (1) and the second, radially outer rotor (2). Coolant from a first coolant supply (I) can be supplied axially to at least one axial bore (6) of the stator (5) from a housing-side coolant supply. The supplied coolant can be guided axially along the axial bore (6) of the stator (5) to cool the stator (5). The coolant supplied to the stator (5) can also be supplied to the second rotor (2) to cool the second rotor (2). Furthermore, an electric machine (19) with the dual-rotor arrangement is proposed. In addition, a vehicle (20) with an electric machine (19) is proposed.

Description

[0001] The present invention relates to a dual-rotor arrangement for an electric machine with a rotor shaft comprising a first rotor and a second rotor in a housing, wherein the rotors are arranged coaxially to the rotor shaft and wherein a housing-mounted stator is arranged radially between the first radially inner rotor and the second radially outer rotor. The invention further relates to an electric machine with the dual-rotor arrangement and to a vehicle with at least one electric machine.

[0002] An example from the prior art is known from DE 10 2021 205 801 A1.

[0003] Dual-rotor arrangements for electric machines are well-known in automotive engineering. Due to the special design of the two coaxially arranged rotors with a radially interposed, housing-mounted inner stator, a complex coolant supply system is required to reduce unwanted heating of the electric machine.

[0004] The state of the art for dual-rotor arrangements is known, for example, from DE 10 2016 208 259 A1 or US 2015 / 0 270 754 A1.

[0005] The present invention is based on the objective of proposing a dual-rotor arrangement, an electric machine with the dual-rotor arrangement, and a vehicle with the electric machine, in which optimal cooling is achieved in a structurally simple manner.

[0006] This problem is solved according to the invention by the features of claim 1, 11, and 12, respectively. Advantageous and claimed embodiments are described in the dependent claims, the description, and the drawings.

[0007] Thus, a dual-rotor arrangement for an electric machine is proposed, wherein the rotor arrangement comprises a rotor shaft with a first rotor and a second rotor in a housing, the rotors being arranged coaxially to the rotor shaft, and a housing-mounted stator being arranged radially between the first radially inner rotor and the second radially outer rotor. To achieve optimal cooling in a structurally simple manner, it is provided that coolant from a first coolant supply can be fed axially to at least one axial bore of the stator via a housing-side coolant supply, that the supplied coolant can be guided axially along the axial bore of the stator to cool the stator, and that the coolant supplied to the stator can be supplied to the second rotor to cool the second rotor.

[0008] In this way, the coolant supplied axially to the stator can be drawn to the second rotor at the end of the stator by the centrifugal forces generated by the rotation of the rotor shaft. This allows for the simple, structurally straightforward cooling of both the stator and the second rotor without the need for additional components. This effectively creates a series cooling flow, first cooling the stator and then the second rotor.

[0009] To make the cooling of the stator and the second rotor structurally simple, the supplied coolant is guided from a first end of the axial bore of the stator to a second end of the axial bore of the stator, wherein a coolant trap geometry is assigned to the second end of the stator and wherein the coolant collected radially outside can be supplied to at least one axial bore running through the second radially outside rotor for cooling the second rotor.

[0010] For example, the coolant trap geometry can be easily formed by a rotor carrier or similar structure connecting the two rotors. In this way, no additional components are required to guide the coolant radially from the stator to the axial bore of the second rotor.

[0011] It is also conceivable that the coolant trap geometry is implemented by a coolant guide element or the like, located at a second end of the axial bore of the stator and facing the rotor carrier.

[0012] In one embodiment of the invention, it may be provided that in the claimed dual-rotor arrangement a first end lamella of the second rotor is used as the coolant trap geometry.

[0013] In the present invention, the coolant trap geometry is implemented at least by a spacer element or the like arranged axially between the associated end of the second rotor and the rotor carrier.

[0014] For example, sleeve-shaped components are conceivable as spacer elements, wherein an inner diameter of the spacer element is larger than the diameter on which at least one axial bore of the second rotor is arranged.

[0015] However, it is also conceivable that an inner diameter of the spacer element is smaller than the diameter range on which the at least one axial bore of the second rotor is arranged, and that the spacer element has at least one recess or the like associated with the axial bore of the second rotor, through which the collected coolant enters the axial bore of the second rotor.

[0016] Another embodiment of the invention can be realized by having an inner diameter region of the spacer element have a slope or the like extending in the direction of the axial bore.

[0017] It is also possible that the spacer element has at least one axially extending bore or the like, which is fluidically connected to the axial bore of the rotor, for the coolant guidance.

[0018] For example, the spacer element in the claimed dual-rotor arrangement can have at least one radially extending bore or the like which is fluidically connected to the axial bore of the rotor.

[0019] A structurally simple way to achieve cooling of the first rotor in addition to cooling the stator and the second rotor in the proposed dual-rotor arrangement is achieved by allowing coolant from a second coolant supply of the housing-side coolant supply to be fed axially to the first rotor, and by allowing the supplied coolant to be guided axially along an inner diameter range of the first rotor to cool the first rotor.

[0020] It is particularly advantageous if the coolant supplied to the first rotor can be directed radially, at least through the axial bore running through the second rotor, to cool the second rotor. In this way, in addition to the cooling flow from the stator, the cooling flow from the first rotor is also used to cool the second rotor. However, it is also conceivable that the cooling flow supplied to the first rotor is discharged from the housing side.

[0021] The problem underlying the invention is also solved by an electric machine with the described dual-rotor arrangement. This results in the advantages already described and further advantages.

[0022] Furthermore, the problem underlying the invention is also solved by a vehicle with at least one electric machine, resulting in the advantages already described and further advantages.

[0023] The present invention is further explained below with reference to the drawings.

[0024] They show: Fig. 1 a schematic view of a dual-rotor arrangement with a first embodiment having a housing-side coolant supply for cooling a stator and a second rotor; Fig. 2 a schematic view of a second embodiment of the dual-rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor, Fig. 3 a schematic view of a third embodiment of the dual-rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 4 a schematic view of an embodiment of the dual-rotor arrangement according to the invention with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 5 a schematic view of a fifth embodiment of the dual-rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 6 a schematic view of a sixth embodiment of the dual-rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 7 a schematic view of a seventh embodiment of the dual-rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 8 a schematic view of an eighth embodiment of the dual-rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 9 a schematic view of a ninth embodiment of the dual-rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 10 a schematic view of a tenth embodiment of the dual-rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 11 a schematic view of an eleventh embodiment of the dual rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 12 a schematic view of a twelfth embodiment of the dual rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 13 a schematic view of a thirteenth embodiment of the dual rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor; Fig. 14 a schematic view of a fourteenth embodiment of the dual rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor as well as with a separate coolant supply for cooling a first rotor; Fig. 15 a schematic view of a fifteenth embodiment of the dual rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor as well as with the separate coolant supply for cooling the first rotor; Fig. 16 a schematic view of a sixteenth embodiment of the dual-rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor, and with the separate coolant supply for cooling the first rotor; and Fig. 17 a schematic view of a seventeenth embodiment of the dual rotor arrangement with the housing-side coolant supply for cooling the stator and the second rotor, and with the separate coolant supply for cooling the first rotor.

[0025] In the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16 to Fig. Figure 17 shows schematic views of different design variants of a dual-rotor arrangement of an electric machine 19 using a vehicle 20 as an example.

[0026] Regardless of the specific design variant, the dual-rotor arrangement comprises a first rotor 1 and a second rotor 2 within a housing 3, with the rotors 1 and 2 arranged coaxially to a rotor shaft 4. A housing-mounted stator 5 is arranged radially between the first, radially inner rotor 1 and the second, radially outer rotor 2.

[0027] To provide a structurally simple coolant supply, at least for cooling the stator 5 and the second rotor 2, coolant from a first coolant supply I of a housing-side coolant supply is fed axially to at least one axial bore 6 of the stator 5, wherein the supplied coolant can be guided axially along the axial bore 6 of the stator 5 for cooling the stator 5, and wherein the coolant supplied to the stator 5 can be supplied to the second rotor 2 for cooling the second rotor 2. The coolant supplied to the stator 5 is guided from a first end of the axial bore 6 of the stator 5 to a second end of the axial bore 6 of the stator 5, wherein a coolant collection geometry is assigned to the second end of the stator 5, and wherein the coolant collected radially outside is supplied to at least one axial bore 7 extending through the second radially outer rotor 2 for cooling the second rotor 2.This results in a coolant flow connected in series via only one coolant supply I from stator 5 and second rotor 2. To optimize cooling, several axial bores 6 are provided around the circumference of the stator 5 and several axial bores 7 are provided around the circumference of the second rotor 2.

[0028] In the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10, Fig. 11, Fig. 12 to Fig. Figure 13 shows various embodiments of the series-connected cooling flow for cooling the stator 5 and the second rotor 2 using the claimed dual-rotor arrangement, while in the Fig. 14, Fig. 15, Fig. 16 to Fig. Seventeen different design variants are shown, each with an additional coolant supply II for cooling the first rotor 1. Regardless of the specific design variant, the coolant supplied to the second rotor 2 is discharged at the end of the axial bore 7, for example, via a drain channel formed by a second end fin 9 on the housing side. The drain channel can also be connected to a housing-side extraction system.

[0029] In Fig. Figure 1 shows a first embodiment in which a rotor carrier 10, connecting the two rotors 1 and 2 to the rotor shaft 4, serves as the coolant collection geometry. The coolant collected radially from the axial bore 6 of the stator 5 due to the rotation of the rotor shaft 4 is fed to the axial bore 7 of the second rotor 2. The coolant collection geometry, or oil collection element, is formed by a centering diameter 11 on the rotor carrier 10. This centering diameter 11 is interrupted to direct the collected coolant into the axial bore 7 of the second rotor 2. To ensure that the coolant flowing from the axial bore 6 of the stator 5 is guided radially, an oil or coolant guide element 12 is provided, forming a radially extending connecting channel 13 axially between the rotor carrier 10 and the oil guide element 12.

[0030] In Fig. Figure 2 shows a second embodiment in which a first end lamella 14 of the second rotor 2 is provided as the coolant trap geometry, with corresponding recesses or grooves through which the coolant is directed into the axial bore 7 of the second rotor 2. Furthermore, arrows indicate that the coolant exiting the axial bore 6 exits through a winding head 15 of the stator 5.

[0031] In the third version variant according to Fig. In contrast to the second version, version 3 includes a bore in the first end lamella 14 of the second rotor 2.

[0032] In Fig. 4, according to one embodiment of the invention, is a spacer element 16 axially between the rotor carrier 10 and the associated coolant trap geometry.

[0033] The end of the second rotor 2 is clamped. The inner diameter of the spacer element 16 is larger than the diameter on which the axial bores 7 of the second rotor 2 are located. This allows the coolant collected radially on the outside to be supplied to each axial bore 7.

[0034] In Fig. Figure 5 shows, in a fifth embodiment, that the inner diameter of the spacer element 16 can also be smaller than the diameter on which the axial bores 7 are located. However, in this case, grooves or recesses are required on the spacer element 16 in the area of ​​the axial bore 7.

[0035] In Fig. Figure 6 shows in a sixth embodiment variant that the spacer element 16 has a slope as its inner diameter area, the slope being such that the coolant is directed to the axial bore 7.

[0036] In Fig. Figure 7 shows, in the context of a seventh embodiment variant, that the spacer element 16 is provided with a stagnation edge at the end of the slope, so that the coolant is stagnated.

[0037] In Fig. Figure 8 shows in an eighth embodiment variant that the spacer element 16 has transverse bores 17 which are connected to the axial bores 7.

[0038] In Fig. Figure 9 shows in a ninth embodiment variant that the spacer element 16 has enlarged axial bores which are connected to the axial bores 7 of the second rotor 2.

[0039] In Fig. Figure 10 shows that the spacer element 16 has axial bores which have a transverse recess 17 at the end which are connected to the axial bores 7 of the second rotor 2.

[0040] In Fig. Figure 11 shows an eleventh variant in which the spacer element 16 has an alternatively designed slope.

[0041] In Fig. Figure 12 shows a twelfth embodiment variant in which the spacer element 16 has a combination of slope and groove to direct the coolant into the axial bores 7 of the second rotor 2.

[0042] In Fig. Figure 13 shows a thirteenth embodiment variant in which the spacer element 16 is replaced by the first end lamella 14 of the second rotor 2, so that the previous embodiment variants with the spacer element 16 can also be applied to the first end lamella 14.

[0043] In Fig. Figure 14 shows a fourteenth embodiment in which a second coolant supply II is provided, which supplies coolant to an inner diameter region 8 of the first rotor 1, so that the supplied coolant is guided axially along the inner diameter region 8 of the first rotor 1 towards the rotor carrier 10. At the end of the inner diameter region 8 associated with the rotor carrier 10, the coolant is guided through axial bores 21 of the rotor carrier 10 and subsequent radial bores 22 of the rotor carrier 10 in order to be discharged on the housing side for cooling an outer stator region.

[0044] As part of a fifteenth variant according to Fig. 15. At the end of the inner diameter area 8 of the first rotor 1, grooves 23 are provided in place of axial and radial bores 21, 22 in the associated rotor carrier 10. Furthermore, guide elements 8 are provided with which a radially extending connecting channel 24 is formed axially between the guide elements 18 and the rotor carrier 10, so that the coolant, together with the coolant exiting from the axial bore 6 of the stator 5, is supplied in a radial direction to the axial bores 7 of the second rotor 2, which is indicated by arrows.

[0045] In Fig. In the context of a sixteenth embodiment variant, unlike the previous embodiment variant, only one guide element 18 is provided next to the axially extending grooves 23, for example as a centering seat, and the radially extending grooves 23, for example as an interrupted stop in the rotor carrier 10.

[0046] A seventeenth variant according to Fig.Figure 17 shows, in addition to the guide element 18 and the grooves 23 in the previous embodiment variants, a guide geometry 25 for coolant guidance at the end assigned to the rotor carrier 10 or at an end lamella of the first rotor 1. Reference sign 1 first rotor 2 second rotor 3 cases 4 Rotor shaft 5 Stator 6 axial bores through the stator 7 axial bores through the second rotor 8 Inner diameter range of the first rotor 9 second end blade of the second rotor 10 rotor carriers 11 centering diameters on the rotor carrier 12 Coolant or oil guide element 13 Connection scandal axial between rotor carrier and oil guide element 14 first end blade of the second rotor 15 Stator winding head 16 Spacer element between rotor carrier and second rotor 17 transverse holes in the spacer element 18 guide element 19 electric machine 20 vehicles 21 axial bore in the rotor carrier 22 radial bores in the rotor carrier 23 slots in the rotor carrier 24 Connection scandal axial between guide element and rotor carrier 25 Guide geometry on the first rotor and I. Coolant supply on the housing side for the stator II. Housing-side coolant supply for the first rotor

Claims

Dual-rotor arrangement for an electric machine (19), comprising a rotor shaft (4) with a first rotor (1) and a second rotor (2) in a housing (3), wherein the rotors (1, 2) are arranged coaxially to the rotor shaft (4) and wherein a housing-mounted stator (5) is arranged radially between the first, radially inner rotor (1) and the second, radially outer rotor (2), wherein coolant from a first coolant supply (I) of a housing-side coolant supply can be supplied axially to at least one axial bore (6) of the stator (5), and wherein the supplied coolant can be guided axially along the axial bore (6) of the stator (5) for cooling the stator (5), characterized in that the coolant supplied to the stator (5) can be supplied to the second rotor (2) for cooling the second rotor (2), and that the supplied coolant flows from a first end of the axial bore (6) of the stator (5) to a second end of the axial bore (6) of the stator (5) is capable of being guided,that a coolant trap geometry is assigned to the second end of the stator (5), and that the radially outer coolant can be supplied to at least one axial bore (7) extending through the second radially outer rotor (2) for cooling the second rotor (2), that the coolant trap geometry is formed by a rotor carrier (10) connecting the two rotors (1, 2), and that the coolant trap geometry is formed by a spacer element (16) arranged axially between the assigned end of the second rotor (2) and the rotor carrier (10). Dual rotor arrangement according to claim 1, characterized in that the coolant trap geometry is formed by a coolant guide element (12) associated with the second end of the axial bore (6) of the stator (5). Dual rotor arrangement according to one of claims 1 or 2, characterized in that the coolant trap geometry is formed by a first end lamella (14) of the second rotor (2). Dual rotor arrangement according to one of claims 1 to 3, characterized in that an inner diameter of the spacer element (16) is larger than the diameter range on which the at least one axial bore (7) of the second rotor (2) is arranged. Dual rotor arrangement according to one of claims 1 to 3, characterized in that an inner diameter of the spacer element (16) is smaller than the diameter range on which the at least one axial bore (7) of the second rotor (2) is arranged, and that the spacer element (16) has at least one recess associated with the axial bore (7) of the second rotor. Dual rotor arrangement according to one of claims 1 to 3, characterized in that an inner diameter region of the spacer element (16) has a slope extending in the direction of the axial bore (7) of the second rotor (2). Dual rotor arrangement according to one of claims 1 to 6, characterized in that the spacer element (16) has at least one axially extending bore which is fluidly connected to the axial bore (7) of the second rotor (2). Dual rotor arrangement according to any one of claims 1 to 7, characterized in that the spacer element (16) has at least one radially extending bore which is fluidly connected to the axial bore (7) of the second rotor (2). Dual rotor arrangement according to one of claims 1 to 8, characterized in that coolant from a second coolant supply (II) of the housing-side coolant supply can be supplied axially to the first rotor (1), and that the supplied coolant can be guided along an inner diameter region (8) of the first rotor (1) in an axial direction to cool the first rotor (1). Dual rotor arrangement according to claim 9, characterized in that the coolant supplied to the first rotor (1) can be supplied in a radial direction to at least one axial bore (7) extending axially through the second rotor (2) for cooling the second rotor (2). Electric machine (19) with a dual rotor arrangement according to one of the preceding claims. Vehicle (20) with at least one electric machine (19) according to claim 11.

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