Dual-rotor arrangement of an electric machine of a vehicle

Abstract

A dual-rotor arrangement for an electric machine (24) 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), and a housing-mounted stator (5) is arranged radially between the first, radially inner rotor (1) and the second, radially outer rotor (2). Coolant can be supplied axially to at least the first rotor (1) via a first coolant supply (I) from a housing-side coolant supply. The supplied coolant can be guided axially along an inner diameter region (6) of the first rotor (1) to cool the first rotor (1). Furthermore, an electric machine (24) with the dual-rotor arrangement is proposed. Additionally, a vehicle (25) with at least one electric machine (24) 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] 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.

[0003] 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.

[0004] This problem is solved according to the invention by the features of claim 1, 18, and 19, respectively. Advantageous and claimed embodiments are described in the dependent claims, the description, and the drawings.

[0005] 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-fixed 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 housing-side coolant supply can be axially supplied to at least the first radially inner rotor, and that the supplied coolant can be guided axially along an inner diameter region of the first rotor to cool the first rotor.

[0006] In this way, the axially supplied coolant can flow along the inner diameter area of ​​the first rotor due to the centrifugal forces caused by the rotation of the rotor shaft, thus cooling the first rotor simply and without additional components.

[0007] In this context, it is particularly advantageous if the coolant supplied to the first rotor can be directed radially through at least one axial bore running through the second rotor to cool it. This effectively creates a series-flowing cooling system for both rotors in a simple design.

[0008] Alternatively, coolant from the housing-side coolant supply can be fed axially to each axial bore running through the second rotor to cool the second rotor. This effectively creates two parallel cooling flows for cooling the two rotors.

[0009] In order to also be able to cool the stator, it is also conceivable within the scope of the invention that a further coolant supply is provided on the housing side, which directs coolant at least into an axial bore of the stator.

[0010] To simplify the cooling of the first rotor, the coolant from the housing-side coolant supply is fed to a first housing-side end of the first rotor. To enable axial flow of the supplied coolant through the first rotor, a suitable coolant trap geometry or similar can be provided at the first end of the first rotor.

[0011] For example, a coolant trap geometry such as a backwater edge or similar feature can be provided at the first end of the first rotor. With the help of this backwater edge and the centrifugal forces acting on the coolant due to the rotor's rotation, an axially directed flow of the coolant is effectively forced.

[0012] For example, within the scope of the present invention, it is conceivable that the inner diameter region of the first rotor, for the axially directed guidance of the coolant from the first end of the first rotor to a second end of the first rotor, has an inner diameter that increases at least section by section as a coolant guide geometry. In this way, the coolant is also guided axially for cooling the first rotor, for example, without a stagnation edge.

[0013] In order to make it structurally easy to enable series-connected cooling flows for cooling the first rotor and the second rotor, the present invention provides that the coolant supplied to the inner diameter area of ​​the first rotor can be supplied to the second rotor via a radially extending connecting channel or the like.

[0014] To make it structurally easy to supply the coolant flowing through the connecting channel to the second rotor, the connecting channel can be connected to the axial bore of the second rotor.

[0015] The design of the connecting channel depends on the design of the two rotors. For example, in a one-piece design of the two rotors, the connecting channel can be designed as a radial connecting bore in a connection area of ​​the two rotors.

[0016] For example, if a two-part design of the two rotors is provided, the connecting channel in a rotor carrier connecting the two rotors to the rotor shaft can be designed as a radially extending connecting bore.

[0017] Within the scope of the present invention, it is also possible that a radially extending connecting channel is formed axially between a sealing disc assigned to the two rotors and the rotor carrier in a two-part embodiment of the two rotors.

[0018] In the present invention, for example, to discharge the coolant into the housing, it can be provided that the coolant supplied to the axial bore of the second rotor can be guided in an axial direction from a first end of the axial bore to a second end of the axial bore and that the coolant can be discharged at the second end of the axial bore via a coolant discharge geometry on the housing side.

[0019] For example, in the proposed dual-rotor arrangement, the coolant drainage geometry can be provided by using an end lamella of the second rotor, associated with the second end of the axial bore, as the coolant drainage geometry.

[0020] Alternatively or additionally, the present invention may provide that the second end of the axial bore of the second rotor is associated with a housing-side suction channel or the like for the housing-side discharge of the coolant.

[0021] For example, if two parallel, separate cooling flows are provided for cooling the two rotors, namely a first cooling flow through the first rotor and a second cooling flow through the second rotor, it can be provided within the scope of the present invention that the coolant supplied to the axial bore of the second rotor can be guided in an axial direction from the second end of the axial bore to a first end of the axial bore and that the coolant at the first end of the axial bore of the second rotor can be discharged together with the coolant from the first rotor via a coolant discharge geometry on the housing side.

[0022] Even in this advantageous design, it can be provided, for example, additionally or alternatively, alongside a suitable coolant drainage geometry, that a housing-side suction channel or the like is assigned to the first end of the axial bore of the second rotor for the housing-side drainage of the coolant.

[0023] The problem underlying the invention is also solved by an electric machine with the dual-rotor arrangement described above. This results in the advantages already described and further advantages.

[0024] Furthermore, the problem underlying the invention can also be solved by a vehicle with at least one electric machine with the dual-rotor arrangement described above, resulting in the advantages already described and further advantages.

[0025] The present invention will now be explained in more detail with reference to the drawings.

[0026] They show: Fig. 1 a schematic view of a dual-rotor arrangement according to the invention with a first embodiment with rotors supplied with coolant in series via a common housing-side coolant supply; Fig. 2 a schematic view of a second embodiment of the dual-rotor arrangement with rotors supplied with coolant in series, Fig. 3 a schematic view of a third embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 4 a schematic view of a fourth embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 5 a schematic view of a fifth embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 6 a schematic view of a sixth embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 7 a schematic view of a seventh embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 8 a schematic view of an eighth embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 9 a schematic view of a ninth embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 10 a schematic view of a tenth embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 11 a schematic view of an eleventh embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 12 a schematic view of a twelfth embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 13 a schematic view of a thirteenth embodiment of the dual-rotor arrangement with rotors supplied with coolant in series; Fig. 14 a schematic view of a fourteenth embodiment of the dual-rotor arrangement with rotors supplied with coolant in parallel by two separate housing-side coolant inlets; Fig. 15 a schematic view of a fifteenth embodiment of the dual-rotor arrangement with rotors supplied with coolant in parallel by two separate housing-side coolant inlets; Fig. 16 a schematic view of a sixteenth embodiment of the dual-rotor arrangement with rotors supplied with coolant in parallel by two separate housing-side coolant inlets; and Fig. 17 a schematic view of a seventeenth embodiment of the dual rotor arrangement with rotors supplied with coolant in parallel and with stator supplied with coolant in parallel by three separate housing-side coolant inlets.

[0027] 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 24, using a vehicle 25 as an example.

[0028] 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.

[0029] To provide a structurally simple coolant supply, at least for cooling the two rotors 1 and 2, coolant from a housing-side coolant supply is fed axially to the first rotor 1 via a first coolant supply I. The supplied coolant is guided axially along an inner diameter region 6 of the first rotor 1 to cool it. To subsequently cool the second rotor 2, the coolant supplied to the first rotor 1 is fed radially through an axial bore 7 extending axially through the second rotor 2. This results in a series coolant flow for both rotors 1 and 2 using only one coolant supply I. To optimize cooling, several axial bores 7 are distributed around the circumference of the second rotor 2.

[0030] 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 coolant flow connected in series for the first rotor 1 and the second rotor 2 using the claimed dual-rotor arrangement, wherein the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 to Fig. Figure 11 shows a one-piece design of the two rotors 1, 2, while Fig. 12 and Fig. Figure 13 shows a multi-part design of the two rotors 1, 2, which are connected to the rotor shaft 4 via a rotor carrier 11.

[0031] In Fig. 1. The coolant or oil is supplied through the housing 3 via an oil guide element 9 to the inner diameter section 6 of the first rotor 1, which is indicated by arrows. At the end of the inner diameter section 6 of the first rotor 1, the coolant is supplied via several bores in a connecting area 8 of the two rotors 1, 2 to the axial bore 7 of the second rotor 2. At the end of the axial bore 7, the coolant is discharged to the housing side through bores in an end fin 10 of the second rotor 2. This is also indicated by arrows in the figures.

[0032] In Fig. Figure 2 shows an alternative coolant supply to the inner diameter region 6 of the first rotor 1, in which an overlap between the housing 3 and the first rotor 1 is provided, so that no oil guide element 9 is required. The coolant supply I is realized through a bore diameter or through an adjusting element or a nozzle.

[0033] Both in the first version variant according to Fig. 1 as well as in the second variant according to Fig. 2 is provided as coolant trap geometry a backwater edge 12 at the first end of the first rotor 1.

[0034] The following design variants according to the 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. 17 is provided for the forced guidance of the coolant, such that the inner diameter region 6 of the first rotor 1 has an inner diameter that increases section by section as a coolant guide geometry for the axially directed guidance of the coolant from the first end of the first rotor 1 associated with the coolant supply I to a second end of the first rotor 1.

[0035] In Fig. Figure 3 shows a third embodiment variant in which a coolant drainage channel is formed between the end lamella 10 and the end of the second rotor 2 to remove the coolant from the axial bore 7 of the second rotor 2.

[0036] In Fig. Figure 4 shows an alternative discharge of the coolant from the axial bore 7 of the second rotor 2 through bores in the end lamella 10 as part of a fourth embodiment variant.

[0037] In Fig. Figure 5 shows a further alternative discharge of the coolant from the axial bore 7 of the second rotor 2, in which a transverse bore is provided at the end of the second rotor 2.

[0038] In Fig. In a sixth embodiment variant, it is provided that a drain bore or suction port 13 for the removal of coolant from the second rotor 2 to the housing side is assigned to the end of the axial bore 7 of the second rotor 2.

[0039] In Fig. Figure 7 shows a seventh embodiment variant in which a recess 14 on the housing side is provided to collect the coolant radially flung out by the rotation, so that the collected coolant is discharged into the housing 3 through a drain hole.

[0040] In Fig. In an eighth design variant, a trap geometry 15 is provided for collecting the coolant instead of the recess 14.

[0041] Fig. Figure 9 shows, in the context of a ninth design variant, that the trap geometry 15 is additionally assigned an O-ring 22 for sealing.

[0042] In Fig. Figure 10 shows a tenth design variant in which the trap geometry 15 is combined with the recess 14 as a jamming edge in the housing 3.

[0043] Fig. Figure 11 shows an eleventh design variant in which a baffle plate 16 is provided to collect the coolant.

[0044] In Fig. Figure 12 shows a twelfth embodiment in which the two rotors 1 and 2 are connected to the rotor shaft 4 via a rotor carrier 11. A radially extending connecting bore 17 is provided in the rotor carrier 11, through which the coolant flows from the inner diameter region 6 of the first rotor 1 into the axial bore 7 of the second rotor 2. The connection between the inner diameter region 6 and the connecting bore 17 can be realized, for example, by an axially arranged bore in the rotor carrier 11.

[0045] In Fig. Figure 13 shows a thirteenth embodiment variant in which an alternative coolant connection from the first rotor 1 to the second rotor 2 is realized via a connecting channel 19 formed between a sealing disc 18 of the two rotors 1, 2 and the rotor carrier 11. As an alternative to the axially extending bores in the rotor carrier 11 already shown for the connection between the inner diameter area 6 and the connecting channel 19, axially extending grooves or the like can also be provided in the rotor carrier 11.

[0046] As part of a fourteenth variant according to Fig. 14 A parallel coolant flow is achieved in the second rotor 2 by means of a further coolant supply II, parallel to the first coolant supply I. Through the second coolant supply II, coolant from the housing-side coolant supply is fed axially to the end opposite the connecting channel 19, i.e., to the second end of the axial bore 7 of the second rotor 2. The coolant supplied to the axial bore 7 of the second rotor 2 via the second coolant supply II is guided axially from the second end to a first end of the axial bore 7 and is discharged together with the coolant coming from the first rotor 1 from the connecting channel 13 via a coolant discharge geometry 20 on the housing side.

[0047] In Fig. Figure 15 shows an alternative coolant discharge on the rotor carrier 11 by means of a housing-side recess 23 for collecting the radially ejected coolant, wherein in Fig. 16 in the context of a sixteenth embodiment variant, a coolant discharge is represented by means of an extraction channel 21.

[0048] As part of a seventeenth variant according to Fig.Figure 17 shows, in addition to the first coolant supply I for the first rotor 1 and the second coolant supply II for the second rotor 2, an additional parallel coolant supply III for the stator 5 in the proposed dual-rotor arrangement. Coolant from the housing 3 is directed into the stator 5 via the third coolant supply III. The coolant coming from the stator 5 through at least one axial bore 26 is discharged into the connecting channel 19 and thus fed to the coolant coming from the first rotor 1. To optimize the cooling of the stator 5, several axial bores 26 are provided on the stator 5, distributed around its circumference. Reference sign 1 first rotor 2 second rotor 3 cases 4 Rotor shaft 5 Stator 6 Inner diameter range of the first rotor 7 axial bores through the second rotor 8 Connection area between the rotors 9 Oil guide element 10 End blade of the second rotor 11 rotor carriers 12 Jam edge 13. Coolant extraction from the housing 14 recesses on the housing side 15 Catch geometry 16 Dust plate 17 Connecting hole 18 Sealing washer 19 Connection channel 20 Coolant drainage geometry 21 Extraction channel 22 O-ring 23 recesses on the housing side 24 electric machine 25 vehicles 26 axial bores through the stator I. Housing-side coolant supply for the first rotor II. Housing-side coolant supply for the second rotor III. Coolant supply on the housing side for the stator

Claims

[1] Dual-rotor arrangement for an electric machine (24), comprising a rotor shaft (4) with a first rotor (1) and with 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-fixed stator (5) is arranged radially between the first, radially inner rotor (1) and the second, radially outer rotor (2), characterized by , that coolant can be supplied axially to at least the first rotor (1) via a first coolant supply (I) of a housing-side coolant supply, and that the supplied coolant can be guided axially along an inner diameter region (6) of the first rotor (1) to cool the first rotor (1). [2] Dual rotor arrangement according to claim 1, characterized by , 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). [3] Dual rotor arrangement according to claim 1, characterized by , that coolant of a second coolant supply (II) of the housing-side coolant supply can be supplied axially on the side of an axial bore (7) extending axially through the second rotor (2) for cooling the second rotor (2). [4] Dual rotor arrangement according to one of the preceding claims, characterized by , that the coolant of the first coolant supply (I) can be supplied to the inner diameter area (6) at a first housing-side end of the first rotor (1) having a coolant trap geometry. [5] Dual rotor arrangement according to claim 4, characterized by , that a stagnation edge (12) is provided at the first end of the first rotor (1) as a coolant trap geometry. [6] Dual rotor arrangement according to one of claims 4 to 5, characterized by, that the inner diameter region (6) of the first rotor (1) for axially guiding the coolant from the first end of the first rotor (1) to a second end of the first rotor (1) has an inner diameter that increases at least section by section as coolant guide geometry. [7] Dual rotor arrangement according to one of claims 4 to 5, characterized by , that the coolant supplied to the inner diameter area (6) of the first rotor (1) can be supplied to the second rotor (2) via a radially extending coolant connection. [8] Dual rotor arrangement according to one of claims 7, characterized by , that the coolant connection is connected to the axial bore (7) of the second rotor (2). [9] Dual rotor arrangement according to one of claims 7 or 8, characterized by, that in a one-piece design of the two rotors (1, 2) a radially extending connecting bore (17) is provided in a connection area (8) between the two rotors (1, 2) as a coolant connection. [10] Dual rotor arrangement according to one of claims 7 or 8, characterized by , that in a two-part design of the two rotors (1, 2) a radially extending connecting bore (17) is provided in a rotor carrier (11) for connecting the two rotors (1, 2) as a coolant connection. [11] Dual rotor arrangement according to claim 7 or 8, characterized by , that in a two-part design of the two rotors (1, 2) as a coolant connection a radially extending connecting channel (19) is provided axially between a sealing disc (18) assigned to the two rotors (1, 2) and the rotor carrier (11) for connecting the two rotors (1, 2). [12] Dual rotor arrangement according to one of claims 2 or 4 to 11, characterized by, that the coolant supplied to the axial bore (7) of the second rotor (2) from the first rotor (1) can be guided in an axial direction from a first end of the axial bore (7) to a second end of the axial bore (7) and that the coolant can be discharged at the second end of the axial bore (7) on the housing side. [13] Dual rotor arrangement according to claim 12, characterized by , that the second end of the axial bore (7) is assigned an end lamella (10) of the second rotor (2) for the discharge of the coolant. [14] Dual rotor arrangement according to claim 12 or 13, characterized by , that the second end of the axial bore (7) of the second rotor (2) is assigned a housing-side suction channel (13) for the housing-side discharge of the coolant. [15] Dual rotor arrangement according to one of claims 3, characterized by, that the coolant supplied to the axial bore (7) of the second rotor (2) via the second coolant supply (II) can be guided in an axial direction from the second end of the axial bore (7) to a first end of the axial bore (7) and that the coolant can be discharged at the first end of the axial bore (7) of the second rotor (2) via a coolant discharge geometry (20) on the housing side. [16] Dual rotor arrangement according to claim 15, characterized by , that the first end of the axial bore (7) of the second rotor (2) is associated with a housing-side suction channel (21) for the housing-side discharge of the coolant. [17] Dual rotor arrangement according to one of the preceding claims, characterized by , that coolant of a third coolant supply (III) of the housing-side coolant supply can be supplied axially on the side of at least one axial bore (26) extending axially through the stator (5) at least for cooling the stator (5). [18] Electric machine (24) with a dual rotor arrangement according to one of the preceding claims. [19] Vehicle (25) with at least one electric machine (24) according to claim 17.

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