A current transmission device for transmitting electric current to the rotor of an electric machine.

Abstract

The present invention relates to a current transmission device for transmitting current to the rotor of an electric machine, comprising two contact carriers (2, 3) each supporting an electrical sliding contact (4, 5) for transmitting current to the rotor, wherein a base carrier (1) supporting and electrically insulating the contact carriers (2, 3) is disposed between the contact carriers, and the device has at least one coolant channel (19, 20), wherein at least one closed circumferential coolant channel (19, 20) for cooling the two contact carriers (2, 3) is at least partially in contact with the base carrier (1) and the contact carrier In the rear (2, 3) elements, a rib structure (13, 14) is provided, which is positioned between each outer side surface (9, 10) of the base carrier (1) and the contact carriers (2, 3) that abut against it. On the base carrier (1), on its outer side surface (9, 10) facing each contact carrier (2, 3), there is a rib structure (13, 14) with one side open and protruding from the surface, which abuts against it and covers it in its axial direction on the open side surface (21, 22) to form a closed circumferential coolant channel (19, 20) together with the respective contact carriers (2, 3).

Description

Technical Field

[0001] The present invention relates to a current transmission device for transmitting current to a rotor of an electric machine, having two contact carriers each carrying an electrical sliding contact for transmitting current to the rotor, and a base carrier that carries the contact carriers and is electrically insulating and is arranged between the contact carriers, and having at least one coolant channel.

Background Art

[0002] German Patent Invention No. 102021122065 is considered the closest prior art. It describes a current transmission device having a base carrier and contact carriers each having brushes on both sides. According to FIG. 6, starting from a lateral inlet, the base carrier has, on its inner wall, lateral and radial channels for the coolant that lead to the outlets on both sides slightly above the rotor opening.

[0003] German Patent Invention No. 102019100729 discloses a brush module for a slip ring system of a current-excited electric machine for a motor vehicle for energizing the rotor of the electric machine. A heat-conducting core surrounded by a holding device for holding the brush carrier aims to dissipate heat from the brush module.

[0004] Furthermore, reference is made to German Utility Model No. 9301792, West German Utility Model Publication No. 6936266, and British Patent Application Publication No. 967623.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem of the present invention is to propose a current transmission device of the aforementioned type that enables improvement of the cooling of the sliding contacts of an electric machine, particularly with regard to performance and operational safety, in a structurally simple and cost-effective manner. [Means for solving the problem]

[0006] According to the present invention, this objective is achieved by providing a rib structure in which at least one closed circumferential coolant channel for cooling two contact carriers is formed between each outer surface of the base carrier and the contact carrier in contact therewith, in the elements of the base carrier and the contact carrier, which at least partially abut each other, and in the base carrier, on the outer surface facing each contact carrier, there is a rib structure having one side open and protruding from the surface, which abuts therewith and covers therewith the respective contact carriers so as not to leak coolant on the open side in the axial direction, thereby forming a closed circumferential coolant channel.

[0007] This is a simple and cost-effective method for improving the cooling of electromechanical electrical sliding contacts, particularly in terms of performance and operational safety. Through the interaction between the elements of the base carrier and each contact carrier, at least one closed circumferential coolant channel is formed between each outer surface of the base carrier and the respective contact carrier in contact with it, without requiring any additional components. Targeted active cooling of the two contact carriers and the electrical sliding contacts they support can be achieved with high cooling capacity thanks to the targeted channel routing.

[0008] In the at least one closed circumferential coolant channel thus formed between each outer surface of the base carrier and each contact carrier in contact with it, the coolant can flow through the closed path without the coolant flowing uncontrolled into the surroundings.

[0009] Therefore, uncontrolled contact between the electrical sliding contacts and the coolant is avoided, which means that the cooling of the electrical sliding contacts can be configured independently of their lubrication. In particular, by increasing the cooling capacity and the flow of the coolant, it is possible to avoid uncontrolled exposure of the electrical sliding contacts to the coolant, especially so-called floating of the electrical sliding contacts, which reliably prevents malfunctions in the operation of the electromechanical device caused by floating.

[0010] According to a further development of the present invention, each rib structure is formed by at least two ribs protruding from a surface, each rib being arranged opposite to each other and circulating in a closed manner, such that one side surface of each rib is open and the open side surface is covered by a contact carrier abutting it to prevent coolant leakage.

[0011] In this regard, it is also advantageous if the ribs preferably form sealing surfaces at each end face of their axially projecting free ends. Preferably, each contact carrier is in contact with the sealing surfaces of the two opposing ribs in such a manner that coolant does not leak out.

[0012] If the contact carriers are preferably configured as plates, the configuration of the present invention can be further simplified. In this context, each contact carrier abuts axially with a flat axial inner side surface to prevent coolant leakage from a planar sealing surface of a coolant-carrying rib structure formed on the axial outer side surfaces of a base carrier facing away from each other, and can easily cover a coolant channel formed between them, each with one side open, to prevent coolant leakage toward the outer side of the open side.

[0013] In an advantageous further development of the present invention, in each case, the coolant channels formed on the outer surface of the base carrier in the coolant-carrying rib structure are coolant-connected to one another. This advantageously allows for the formation of a common coolant inlet and a common coolant outlet on one of the outer surfaces of the base carrier, so that the coolant channels on both outer surfaces of the base carrier can be connected from one outer surface of the base carrier to a coolant supply, particularly to an oil circuit of an electromechanical device.

[0014] In a further advantageous development of the present invention, on the outer side surface of the base carrier, a coolant inlet and a coolant outlet each penetrate the contact carrier that abuts them axially toward the outer side surface, preferably in the form of a tubular extension, for example, protruding above the coolant outlet as a connecting component.

[0015] Preferably, the coolant inlet and coolant outlet are formed to be aligned inward with their respective extensions, and then penetrate the base carrier and flow through to the other outer surface of the base carrier, with each flow opening directly opening into a coolant channel formed on the rib structure on this outer surface of the base carrier.

[0016] Alternatively, each coolant discharge opening can be formed on each outer side surface of the base carrier at the geodetic lowest point on the rib structure for gravity-driven discharge on the rib structure. Preferably, in this regard, each discharge opening is formed on the outer side rib of the rib structure, furthest from the central through-opening on the base carrier for the passage of the rotor-supporting shaft, relative to the inner side rib of the rib structure. This prevents uncontrolled contamination of the electrical sliding contacts by the coolant. In this context, the common coolant inlet described above is preferably provided for coolant channels formed on both axial outer sides of the base carrier on each rib structure.

[0017] A plurality of through-holes extending between the axial outer surfaces of the base carrier are preferably provided for coolant connections, each of which opens directly into a coolant channel formed on the coolant-carrying rib structure on the axial outer surfaces of the base carrier, facing away from each other in each case. In this way, both coolant channels are connected to form a cooling circuit.

[0018] As part of a further development of the present invention, the coolant channels formed on the outer surface of the base carrier on the coolant-carrying rib structure in each case are formed to coincide with each other and offset circumferentially. This further simplifies the structure and production of the base carrier.

[0019] In each case, it is even more advantageous when, in a top view, the coolant channels formed on the outer surface of the base carrier on the coolant-carrying rib structure extend in a meandering manner with multiple loops arranged sequentially in the circumferential direction. In this way, particularly uniform and comprehensive cooling can be achieved, especially with high cooling capacity.

[0020] In this context, a further advantage is preferably achieved in which at least some of the loops extend in contact with, at least partially, the region of the inner surface of the contact carrier where the electrical sliding contacts are located on the outer surface of the contact carrier. This facilitates the achievement of targeted active cooling of the region of the contact carrier that becomes the hottest during operation.

[0021] According to a possible further development of the invention, for the controlled minimum lubrication of the electrical sliding contacts, spray openings aligned in a targeted manner are provided in each case on the rib structure. Preferably, at least one spray opening is directed in each case in a targeted manner here to the respective electrical sliding contact. In this context, the minimum lubrication can be adjusted as controlled by the configuration of the spray openings. Each spray opening is preferably formed on the base carrier as a channel open on one side, and in each case is covered by the contact carrier abutting it so that the coolant does not leak.

[0022] In the proposed current transmission device, preferably, plastic is provided as the material of the base carrier, which enables particularly simple, lightweight and cost-effective production, especially by injection molding.

[0023] Preferably, the base carrier is integrally formed as an injection-molded component, has a simple configuration for production in an injection mold, can be easily removed from the injection mold and especially has no undercuts. Thereby, the base carrier can be pre-assembled particularly easily to the contact carrier, and the proposed current transmission device can be axially put on the rotor shaft of an electric machine as a pre-assembled component having a central through-opening and can be easily attached to a stationary component, especially the stator housing of the electric machine.

[0024] The invention will be described hereinafter based on the drawings.

Brief Description of the Drawings

[0025] [Figure 1] A perspective view of a current transmission device according to the invention for transmitting current to the rotor of an electric machine is shown. [Figure 2] A top view of the current transmission device on the first axially outer side is shown. [Figure 3] A top view of the current transmission device on the second axially outer side is shown. [Figure 4] Shows a single perspective view of the base carrier of the current transmission device. [Figure 5] Shows a top view of the first axially outer side surface of the base carrier. [Figure 6] Shows a top view of the second axially outer side surface of the base carrier. [Figure 7] Shows a plan view of the first axially outer side surface of the base carrier, with the first contact carrier of the current transmission device indicated by a dashed line. [Figure 8] Shows a top view of the base carrier of the second axially outer side surface, with the second contact carrier of the current transmission device indicated by a dashed line.

Mode for Carrying Out the Invention

[0026] The drawings show, by way of example, various perspectives and embodiments of a current transmission device according to the present invention for transmitting current to the rotor of an electric machine.

[0027] According to FIGS. 1 to 3, the current transmission device includes an integrally formed base carrier 1, and two contact carriers 2 and 3 each carrying three electrical sliding contacts 4 and 5 for transmitting current to the rotor. The base carrier 1 is disposed between the contact carriers 2 and 3 so as to be coaxial with the contact carriers 2 and 3, carries the contact carriers 2 and 3, and electrically insulates them. The base carrier 1 and the contact carriers 2 and 3 form a central through-opening 6 on a current transmission device arranged to be fixed in order to pass through the shaft of an electric machine carrying the rotor.

[0028] The base carrier 1 and contact carriers 2 and 3 are configured in a plate shape. Preferably, the contact carriers 2 and 3 are configured as circular contact plates. With their planar inner sides 7 and 8 facing axially toward the base carrier 1, they are fixed to the axial outer sides 9 and 10 of the base carrier 1, which face away from each other, for example, by axial screw connections. Electric sliding contacts 4 and 5 are arranged and fixed on the axial outer sides 11 and 12 of the contact carriers 2 and 3, which face away from each other, so as to be evenly distributed around the entire circumference.

[0029] In order to dissipate the heat generated at the electrical sliding contacts 4 and 5 during operation, closed circumferential coolant channels 19 and 20 are formed in each case on the surface of the base carrier 1 on the axial outer side surfaces 9 and 10 of the base carrier 1 and on the surface of the contact carriers 2 and 3, thereby cooling the contact carriers 2 and 3.

[0030] To form coolant channels 19, 20, rib structures 13, 14, each having one side open axially, are provided on the axially outer sides 9, 10 of the base carrier 1 (Figures 4-6). Each of the rib structures 13, 14 is formed by two ribs 15, 16 and 17, 18, is integrally formed with the base carrier 1, and projects vertically and axially from the planar axially outer sides 9, 10 of the base carrier 1.

[0031] Ribs 15, 16 and 17, 18 each form a closed circumferential boundary wall such that they each define closed circumferential coolant channels 19, 20 between them, and are arranged continuously opposite to each other at the same distance from each other, with the coolant channels 19, 20 opening to the outer sides in the axial direction. In this regard, the axially open sides 21, 22 of the cooling channels 19, 20 are each covered by contact carriers 2, 3 that abut them in the axial direction to prevent coolant leakage (Figures 1-3).

[0032] In this way, the ribs 15 and 16 on the first axial outer side surface 9 of the base carrier 1, which the first contact carrier 2 abuts in the axial direction, form a first closed circumferential coolant channel 19, and the ribs 17 and 18 on the second axial outer side surface 10 of the base carrier 1, which the second contact carrier 3 abuts in the axial direction, form a second closed circumferential coolant channel 20. Preferably, the coolant channels 19 and 20 are circumferentially sealed to prevent coolant leakage to the surroundings.

[0033] For sealing, the ribs 15, 16 and 17, 18 each form planar sealing surfaces 23, 24 and 25, 26 (Figures 4-8) at the end faces of their freely projecting axial ends, and the respective contact carriers 2, 3 abut against them axially to prevent coolant leakage on their respective planar axial inner sides. If necessary, appropriate additional seals can also be provided.

[0034] In this way, the contact carriers 2 and 3 are also axially supported on ribs 15, 16 and 17, 18. For further support, as shown in the figure, circularly extending support ribs 47 and 48 can be provided on both axial outer sides 9 and 10 of the base carrier 1, which are integrally formed with the base carrier 1. The support ribs 47 or 48 on each outer side 9 and 10 are preferably three in each case, and are evenly distributed circumferentially and coaxially with the central through-opening 6 in the region of the circular central through-opening 6. In this way, the contact surface on the base carrier 1 for supporting the contact carriers 2 and 3 can be kept small, thereby keeping the heating of the contact surface low.

[0035] On the axial outer sides 9 and 10 of the base carrier 1, the ribs 15, 16 and 17 and 18, and the coolant channels 19 and 20 formed between them, each extend in a meandering manner in the circumferential direction with multiple loops arranged in succession when viewed from above in the axial direction (Figures 4-8). In each case, the inner ribs 16 and 18 extend closer to the central through-opening 6, while the outer ribs 15 and 17 extend further away from the central through-opening 6 in this respect. This channel routing enables uniform active cooling of the contact carriers 2 and 3 and the electro-sliding contacts 4 and 5 located on them, with high cooling capacity.

[0036] In this regard, the coolant channels 19 and 20 are routed such that, in each case, three inner loops 27 or 28 are formed, each extending particularly far inward toward the central through-opening 6, so that they each extend in contact with the region of the inner side surfaces 7 and 8 of the contact carriers 2 and 3 where the electric sliding contacts 4 or 5 are located on the outer side surfaces 7 and 8 of the contact carriers 2 and 3 (Figures 7 and 8). Thus, the channel routing of the coolant channels 19 and 20 allows for targeted cooling of the region of the contact carriers 2 and 3 where the greatest heat is generated, in a simple manner.

[0037] As shown in Figures 4-6, a plurality of through-hole openings 29, 30 or 31, 32 extending between the axial outer surfaces 9, 10 of the base carrier 1 are preferably provided for coolant connections, and each of the through-hole openings opens directly into coolant channels 19, 20 formed on rib structures 13, 14 on the axial outer surfaces of the base carrier 1, which in each case face away from each other.

[0038] Therefore, the coolant channels 19 and 20 form a common cooling circuit that can be connected to the vehicle's coolant supply section on the first axial outer side surface 9 of the base carrier via a common coolant inlet 33 and a common coolant outlet 34. For example, oil from an electromechanical transmission oil circuit can be used as a coolant.

[0039] The coolant inlet 33 and coolant outlet 34 are each formed integrally with the base carrier 1, preferably as connecting parts, as tubular extensions 35 and 36 projecting axially outward on the outer sides 9 and 10 (Figures 1, 2, and 4). The extensions 35 and 36 allow the coolant inlet 33 and coolant outlet 34 to project axially through the contact plates 2 and 3 at through openings 37 and 38, respectively, reaching the outer sides 7 and 8 of the contact plates 2 and 3 (Figure 1).

[0040] In the regions of the coolant inlet 33 and coolant outlet 34, the ribs 15 and 16 are connected to each other by connecting webs 39 and 40, which terminate flush with each other at their free-axis end faces, thereby blocking the coolant channel 19 (Figures 4 and 5). The connecting webs 39 and 40 are integrally formed with the ribs 15 and 16 and the base carrier 1.

[0041] In the axially inward direction, the coolant inlet 33 and coolant outlet 34 extend from their respective connecting webs 39 and 40 to the second axially outward side surface 10 of the base carrier 1, respectively, as axial through holes 41 and 42 on the base carrier 1, so as to be aligned in the axial direction with their respective extensions 35 and 36, and open directly into the coolant channel 20 formed therein (Figure 6).

[0042] The connecting webs 39 and 40 form planar sealing surfaces 43 and 44 on their axial end faces, and these sealing surfaces 43 and 44 in each case are planarly embedded in the sealing surfaces 23 and 24 on the end faces of the ribs 15 and 16. The contact carrier 2 abuts against the base carrier 1 at the sealing surfaces 43 and 44 to prevent coolant leakage in the axial direction and seals the areas of the through openings 37 and 38 on the contact carriers 2 and 3.

[0043] The through holes 29, 30 or 31, 32 for the coolant connections of the coolant channels 19, 20 have a rectangular cross-sectional profile and are located within the coolant channels 19 on both sides of the connecting webs 39, 40 directly adjacent to them (Figures 4 and 5).

[0044] The coolant entering the coolant inlet 33 on the first axial outer side surface 9 of the base carrier 1 first enters the second coolant channel 20 on the second axial outer side surface 10 of the base carrier 1 via the through hole 41, and can be dispersed in both channels or in the circulation direction. The coolant flows into the first coolant channel 19 on the first axial outer side 9, returns to the second coolant channel 20 via the coolant connection parts of the through holes 29, 30 or 31, 32, and can be discharged at the coolant outlet 34 via the through hole 42 and the extended portion 36 of the first axial outer side surface 10 of the base carrier 1.

[0045] Alternatively, as shown in Figures 7 and 8, the coolant discharge openings 45, 46 can be formed on the rib structures 13, 14 on the axial outer sides 9, 10 of the base carrier 1, preferably located at the geodetic lowest point for gravity-dependent discharge. In this regard, the corresponding discharge openings 45, 46 are preferably formed in each case on the outer ribs 15 or 17 of the respective rib structures 13, 14 to avoid uncontrolled contamination of the electro-sliding contacts 4, 5 by the coolant in the area of ​​the central through-opening 6.

[0046] In order to enable minimal lubrication of the electrosliding contacts 4 or 5 on the contact carriers 2, 3 via cooling channels 19, 20 formed by the coolant-carrying rib structures 13 or 14, in further alternative embodiments, as shown in Figures 4-6, it is possible to provide spray openings 49 or 50 formed on the coolant-carrying rib structures 13 or 14 on both axial outer sides 9, 10 of the base carrier 1 in each case. Each spray opening 49 or 50 is assigned to one electrosliding contact 4 or 5. In the spray openings 49 or 50, spray oil from the coolant circuit can be dispersed onto the electrosliding contacts 4 or 5 in a targeted and controlled manner.

[0047] Each of the spray openings 49 or 50 is positioned to originate from an inner rib 16 or 18 on an inner loop 27 or 28 facing the apex region of the central through-opening 6. To achieve targeted alignment of the spray openings 49 or 50 and guidance of the sprayed oil, each is formed as a channel extending from the outer ribs 15, 17, which extends straight to the central through-opening 6 and is aligned at its ends to be targeted to the respective electrosliding contacts 4, 5.

[0048] For this purpose, the extended portions 51 or 52 are provided on the outer surface of the outer rib 15 or 17 in the direction of the central through hole 6, extending integrally with the through hole and the base carrier 1. Each of these extended portions 51 or 52 forms a spray channel on its axial outer surface, which is open axially outward in a recess, and is covered by the respective contact carriers 2 and 3 that abut it, preventing coolant from leaking onto the open surface. In this regard, the extended portions 51 and 52 extend to the edge of the central through opening 6, and terminate on one end facing the free end of the rib 15 and 17, and on the other end at the axial end face so as to be flush with the central through opening 6.

[0049] Pressing means 53 or 54 for pressing the sliding contacts 4 or 5, particularly spring means, preferably helical coil springs, are provided on both axial outer sides of the base carrier 1, preferably retaining pins or bolts 55 or 56 formed integrally with the base carrier (Figures 1-3). These are guided through the contact carrier so as to protrude axially on the axial outer sides of the base carrier 1. The helical coil springs 53 or 54 are axially attached to each of the retaining pins 55 or 56, and their free spring legs bias each electrical sliding contact 4 or 5 inward toward the central through-opening 6 (Figure 1).

[0050] The base carrier 1 is made of an electrically insulating material, preferably plastic. Considering the coolant-carrying rib structures 13 and 14 in particular, in this context they have no undercuts and are particularly simple in construction as injection-molded components, thus allowing them to be easily produced by and removed from injection molds. Therefore, the base carrier 1 can be produced integrally by injection molding in a particularly easy, cost-effective manner.

[0051] The contact carriers 2 and 3 are made of a conductive material, particularly a metal, preferably a non-ferrous metal, such as brass. They can be produced particularly easily and cost-effectively by sheet metal, especially by integrally punching and bending as punched and bent parts. According to Figures 1-3, each of the contact carriers 2 and 3 is connected to a power source, particularly the vehicle's electrical system, via electrical connection tabs 59 or 60 having electrical contacts integrally formed with them. The contact carriers 2 and 3 are energized so that the electrical sliding contacts 4 and 5 can be electrically connected in a simple manner, preferably by material bonding, for example, by soldering or welding, via connecting wires 61 and 62 connected to their respective contact plates 2 and 3. The electrical sliding contacts 4 and 5 are preferably configured as conductive, so-called brushes, and create electrical contacts with slip rings (not shown) positioned on the rotor shaft for rotor current supply.

[0052] As shown in Figures 1-3 and 5-8, axial through holes 63 and 64 corresponding to the electrical connection tabs 59 and 60 of the contact carriers 2 and 3, which are arranged in contact with each other, are provided on the base carrier 1, and the electrical contacts of the connection tabs 59 and 60 of both contact carriers 2 and 3 can be electrically connected, for example, by inserting cable lugs, from the axial outer sides 9 and 10, preferably from the second outer side 10 of the electrical base carrier 1.

[0053] As shown in Figures 1, 2, 4, 5, and 7, a circumferential housing wall 65 that freely protrudes onto the first axial outer surface 9 is integrally formed with the base carrier 1. It has a plurality of, preferably three, axial screw connections 66 integrated with the housing wall 65 at its outer edge (Figures 1-3), which are evenly distributed around the circumference and protrude from the first axial outer surface 9. The screw connections 66 and mounting aids 67 allow the current transmission device to be fixed to the electromachine, preferably at a central position on the stator housing.

[0054] In this case, the base carrier 1, having pre-assembled contact carriers 2 and 3, is fitted over the central through-opening 6 on the rotor shaft of the electromachine and can be screw-fastened to the stator housing at the axial first outer side 9, i.e., the rear, of the base carrier 1 or the current transmission device. In this regard, the coolant inlet 33 and coolant outlet 34 can also be connected to the first axial outer side 9, for example, to the transmission oil circuit of the electromachine. Both contact plates 2 and 3 can be electrically connected to connecting tabs 55 and 56 at the free second axial outer side 10, i.e., the front side of the base carrier 1 or the current transmission device. [Explanation of Symbols]

[0055] 1 Base Carrier 2. First contact carrier 3. Second contact carrier 4. Sliding contacts 5. Sliding contacts 6 Through-opening 7 Inside the first contact carrier 8 Inside the second contact carrier 9. First outer side of the base carrier 10. Second outer side of the base carrier 11 Outer side of the first contact carrier 12 Outer side of the second contact carrier 13 Rib structure 14 Rib structure 15 Outer ribs 16 Inner Rib 17 Outer Rib 18 Inner Rib 19. First coolant channel 20 Second coolant channel 21 Open side 22 Open side 23. Sealing surface 24 sealing surface 25 sealing surface 26 sealing surface 27 Inner Loop 28 Inner Loop 29 Through hole 30 Through holes 31 Through hole 32 Through holes 33 Coolant Inlet 34 Coolant outlet 35 Extensions, connecting parts 36 Extensions, connecting parts 37 Through-opening 38 Through-opening 39 Connect to the Web 40 Connect to the Web 41 Through hole 42 Through hole 43. Sealing surface 44 sealing surface 45 Opening 46 openings 47 Support Ribs 48 Support Ribs 49 Spray opening 50 Spray opening 51 Extension part 52 Extension 53 Pressing means, spring means, helical coil spring 54 Pressing means, spring means, helical coil spring 55 Retaining pin or bolt 56 Retaining pin or bolt 57 No allocation 58 No allocation 59 Connection tab 60 Connection tab 61 connecting wires 62 connecting wires 63 Through hole 64 Through holes 65 Housing Walls 66 Screw connection 67 Mounting elements

Claims

1. A current transmission device for transmitting current to the rotor of an electric machine, comprising two contact carriers (2, 3) each supporting an electrical sliding contact (4, 5) for transmitting current to the rotor, and a base carrier (1) supporting and electrically insulating the contact carriers (2, 3) disposed between the contact carriers, wherein the current transmission device has two contact carriers (2, 3) and at least one coolant channel (19, 20), wherein at least one closed circumferential coolant channel (19, 20) for cooling the two contact carriers (2, 3) is at least partially in contact with the elements of the base carrier (1) and the contact carrier A current transmission device is provided, characterized in that, in the rear (2, 3) elements, a rib structure (13, 14) is formed between each outer side surface (9, 10) of the base carrier (1) and the contact carriers (2, 3) that abut therewith, and on the base carrier (1), on its outer side surface (9, 10) facing the respective contact carriers (2, 3), there is a rib structure (13, 14) which is open on one side and protrudes from the surface, and together with the respective contact carriers (2, 3) that abut therewith and cover therewith so as not to leak coolant on their open side surfaces (21, 22) in the axial direction, the rib structure (13, 14) forms the closed circumferential coolant channel (19, 20).

2. The current transmission device according to claim 1, characterized in that the rib structure (13, 14) is formed by at least two ribs (15, 16, 17, 18) protruding from the surface, and the ribs (15, 16, 17, 18) are each arranged facing each other and circulating in a closed manner, so that they define a closed circumferential coolant channel (19, 20) between them, where one side is open and the open side (21, 22) is covered by contact carriers (2, 3) that abut thereto to prevent coolant leakage.

3. The current transmission device according to claim 2, characterized in that each of the ribs (15, 16, 17, 18) forms a sealing surface (23, 24, 25, 26) at the end face of the free end that protrudes in the axial direction thereof, and the contact carriers (2, 3) are in contact with the sealing surfaces (23, 24, 25, 26) of two opposing ribs (15, 16 and 17, 18) so as not to leak coolant.

4. The current transmission device according to claim 3, characterized in that the contact carriers (2, 3) are configured as plates, and each is in axial contact with the planar sealing surfaces (23, 24, 25, 26) of the rib structures (13, 14) formed on the outer surfaces (9, 10) of the base carrier (1) facing opposite directions, by their flat axial inner surfaces (7, 8), so as to prevent coolant leakage, and each covers the coolant channels (19, 20) formed between them so as to prevent coolant leakage toward the outer surfaces.

5. The current transmission device according to any one of claims 1 to 4, characterized in that the coolant channels (19, 20) formed in each case on the outer side surfaces (9, 10) of the base carrier (1) on the rib structures (13, 14) are coolant-connected (29, 30, 31, 32) to one another, and a common coolant inlet (33) and a common coolant outlet (34) for the coolant channels (19, 20) positioned on each of the two axial outer side surfaces (9, 10) are formed on the rib structure (13) of the outer side surface (9) of the base carrier (1).

6. The current transmission device according to any one of claims 1 to 5, characterized in that the coolant channels (19, 20) formed on the rib structures (13, 14) each extend in a meandering manner in an axial top view with a plurality of loops (27, 28) arranged sequentially in the circumferential direction, and the plurality of loops (27, 28) are at least partially in contact with the region on the inner side surfaces (7, 8) of the contact carriers (2, 3) on which the electric sliding contacts (4, 5) are arranged on the outer side surfaces (11, 12) of the contact carriers (2, 3).

7. The current transmission device according to any one of claims 1 to 6, characterized in that, in each case, targeted and aligned spray openings (49, 50) are provided on the rib structure (13, 14) for controlled and minimal lubrication of the electrical sliding contacts (4, 5).

8. The current transmission device according to any one of claims 1 to 7, characterized in that plastic is provided as a material for the base carrier (1), and the base carrier (1) is integrally formed as an injection-molded component.

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