Transmission device for transmitting electrical current to a rotor of an electrical machine

Abstract

The invention relates to a transmission device for transmitting electrical current to a rotor of an electrical machine, comprising two contact carriers (2, 3), each carrying electrical sliding contacts (4, 5), and comprising at least one base carrier (1) arranged between the contact carriers (2, 3), against which the contact carriers (2, 3) bear at least in sections and which supports them, characterized in that for cooling at least one contact carrier (2, 3), at least one separate cooling element (11, 12) through which coolant can flow is provided, which cooling element is open on one side and is inserted into a corresponding recess (15, 16) on the surface (9, 10) of the base carrier (1) and is made of elastic material at least in sections to seal the open side (54, 55) of the cooling element (11, 12) from the adjacent contact carrier (2, 3).

Description

[0001] The invention relates to a transmission device for transmitting electrical current to a rotor of an electrical machine according to the type defined in more detail in the preamble of claim 1.

[0002] DE 10 2019 100 729 B4 discloses a brush module for a slip ring system of a current-excited electric machine for a motor vehicle for supplying current to a rotor of the electric machine. A heat-conducting core enclosed in a holding device for holding the brush holder is provided for heat dissipation from the brush module.

[0003] The invention is therefore based on the object of proposing a transmission device of the aforementioned type which, in a structurally simple manner, ensures reliable cooling of the electrical sliding contacts for power transmission to an electrical machine.

[0004] The problem is solved by the features of claim 1. Further advantageous and claimed embodiments emerge from the respective subclaims, the description, and the drawings.

[0005] Thus, a transmission device for transmitting electrical current to a rotor of an electrical machine is proposed. The transmission device comprises two contact carriers, each carrying electrical sliding contacts, and at least one base carrier arranged between the contact carriers, against which the contact carriers rest at least in sections and which supports them. To cool at least one contact carrier, at least one separate cooling element is provided, through which coolant can flow and is open on one side. This cooling element is inserted into a corresponding recess on the surface of the base carrier and is made of elastic material, at least in sections, to seal the open side of the cooling element from the adjacent contact carrier.

[0006] In this way, active cooling of the contact carrier with high cooling performance can be achieved by simply inserting the cooling element into the surface of the base carrier. The cooling element can be designed as a simple insert or a simple inlay.

[0007] The elastic properties of the cooling element increase the sealing effect, allowing for a secure seal between the cooling element and the contact carrier, which is located on the open side of the cooling element, and the cooling element connections on the base support. Local coolant leaks are thus reliably avoided. Furthermore, component tolerances on the adjacent contact carrier and on the base support, particularly at the cooling element connections on the latter, can be compensated for. This allows the base support, in particular, to be manufactured easily and cost-effectively, for example, by injection molding.

[0008] In a preferred embodiment of the invention, elastomer is provided as the material for the cooling element, whereby the cooling element can be produced particularly easily and inexpensively, in particular by injection molding.

[0009] A further development of the invention provides for the cooling element to be designed in a channel shape and form a cooling circuit in which several cooling loops are arranged one behind the other in a plane. This allows for particularly space-saving installation in a recess, preferably designed as a groove, on the base support, which is also preferably plate-shaped. This is especially true when the contact carriers resting on the base support are plate-shaped.

[0010] In a further preferred embodiment, the cooling element forms a coolant channel that is open on one side. The coolant channel is preferably designed as a groove on the cooling element. It preferably has a U-shaped cross-sectional profile.

[0011] In a further preferred embodiment of the invention, the cooling element forms flat sealing surfaces lying in one plane on the open side, with which it rests elastically in a coolant-tight manner on the flat inner side of the contact carrier.

[0012] In a further advantageous embodiment of the invention, the cooling element is preferably arranged in a corresponding recess on the base support with the cooling loops for cooling the inside of the contact support in the area of ​​the sliding contacts attached to the outside of the contact support. This arrangement enables particularly effective, targeted cooling at the point where the heat to be dissipated is generated.

[0013] A particularly simple coolant connection of the coolant channel to the coolant supply of the base support can be achieved in that the cooling element preferably forms a coolant inlet opening with a coolant-carrying coolant inlet nozzle and a coolant outlet opening with a coolant-carrying coolant outlet nozzle, wherein the nozzles are each elastically pressed in a coolant-tight manner with a radial sealing surface formed on their outer diameters on the inner diameter of a coolant inlet opening on the base support and on the inner diameter of a coolant outlet opening on the base support.

[0014] In a particularly preferred embodiment, two separate cooling elements are provided for cooling both contact carriers. Preferably, a separate cooling element is arranged in a corresponding recess on each side of the base carrier facing the contact carriers, and each is sealed on the open side of the cooling element by an adjacent contact carrier.

[0015] Preferably, the coolant inlet opening and the coolant outlet opening are each designed as a through-hole on the base support, so that at each end of the coolant inlet opening, a cooling element with the respective coolant inlet nozzle and at each end of the coolant outlet opening, a cooling element with the respective coolant outlet nozzle is pressed in a coolant-tight manner.

[0016] Accordingly, the coolant connection of both cooling elements to the base support can be reached jointly via a coolant inlet and outlet opening designed as a through hole on the base support.

[0017] It is also advantageous if a mounting stop is provided, preferably at the inner diameter of the coolant inlet and outlet openings on the base support, for the respective end of the inserted coolant inlet and outlet nozzles to be positioned. This allows the cooling element with the nozzles to be precisely positioned in the coolant inlet and outlet openings on the base support.

[0018] To ensure even distribution of the coolant in the cooling circuit of the cooling element, the size of the flow cross-section of the coolant channel formed on the cooling element can vary in sections. Preferably, the shortest section of the coolant channel, located between the coolant inlet and the coolant outlet, is designed with smaller flow cross-sections than the rest of the channel.

[0019] A possible further embodiment of the invention provides that the respective cooling element is sealed with additional sealing compound or adhesive, at least in the area of ​​the sealing surfaces to the base support and / or in the area of ​​the sealing surfaces to the contact support, which is adjacent to the inside. Alternatively, the respective cooling element can be welded to the base support and / or to the respective contact support, at least in the area of ​​the sealing surfaces.

[0020] Further claimed features of the invention will become apparent from the following description and the drawings, which further explain the present invention. They show: Fig. 1 and Fig. 2 a side view of a transmission device according to the invention for transmitting electrical current to a rotor of an electrical machine, Fig. 3 and Fig. 4 a cross-section of the transmission device along the section lines AA and BB in Fig. 1, Fig. 5 and Fig. 6 a perspective view of a cooling element of the transmission device, Fig. 7 and Fig. 8 a side view of the base support of the transmission device, Fig. 9 and Fig. 10 a side view of the base carrier with the respective cooling element and the position of the sliding contacts of the contact carriers indicated by dashed lines.

[0021] The figures show various views of a transmission device for transmitting electrical current to a rotor of an electrical machine by way of example.

[0022] After Fig. 1 to 4 and 7 to 10, the transmission device comprises a one-piece base support 1 and two contact supports 2, 3, each carrying three electrical sliding contacts 4, 5 for transmitting electrical current to the rotor (not shown). The base support 1 is arranged coaxially between the contact supports 2, 3, supporting them and electrically insulating them. The base support 1 and the contact supports 2, 3 form a central through-opening 6 on the stationary transmission device for the axial passage of a shaft (not shown) of the electrical machine that supports the rotor.

[0023] The base support 1 and the contact supports 2, 3 are each plate-shaped. The latter are preferably designed as circular contact plates and are fastened with their flat inner sides 7, 8 axially facing the base support 1 to opposite axial sides 9, 10 of the base support 1, for example via axial screw connections. The transmission device can be fastened to a stationary component, for example the stator housing of the electrical machine, via further axial screw connections 41. On the opposite axial outer sides of the contact supports 2, 3, three electrical sliding contacts 4, 5 are arranged, for example, evenly distributed over the circumference and fastened in holders 44, 45 on the contact supports 2, 3.

[0024] According to Fig. 1, 2, 4 to 8, two identical separate cooling elements 11, 12 are provided for cooling the contact carriers 2, 3 and dissipating the heat generated at the electrical sliding contacts 4, 5 during operation. The cooling elements 11, 12 are each made of a single piece from an elastic material, preferably elastomer, and each form a coolant channel 13, 14 open on one side through which coolant can flow. The coolant channels 13, 14 are each designed as a groove on the front side of the cooling elements 11, 12 and form a U-shaped cross-sectional profile ( Fig. 3 and Fig. 4). The cooling elements 11, 12 are each inserted into a corresponding recess 15, 16 on the axial sides 9, 10 of the base support 1 facing the respective contact carrier 2, 3, with the open side 54, 55 of the coolant channels 13, 14 directed axially outwards.

[0025] On the respective open side 54, 55 of the coolant channels 13, 14, the cooling elements 11, 12 form flat axial sealing surfaces 17, 18 and 19, 20, respectively, with which they rest axially elastically against the flat inner sides 7, 8 of the contact carriers 2, 3 in a coolant-tight manner, so that the coolant channels 13, 14 are sealed on the respective open side 54, 55 by the adjacent contact carriers 2, 3 ( Fig. 3 and Fig. 4). The elastic contact increases the sealing effect with the contact carriers 2, 3 resting on the open side 54, 55. The cooling elements 11, 12 are held axially in the respective recess 15, 16 by the screw connection of the contact carriers 2, 3 to the base carrier 1 and are covered on the open side 54, 55 by the respective adjacent contact carriers 2, 3 and are elastically pressed against the contact carriers 2, 3 with the axial sealing surfaces 17, 18 and 19, 20, respectively.

[0026] After Fig. 5 and Fig. 6, the cooling elements 11, 12 are each designed in a channel shape. They each form a cooling circuit in which several cooling loops 21, 22 arranged one behind the other are arranged in a plane such that the cooling elements 11, 12 can each be inserted on a flat side 9, 10 of the plate-shaped base support 1. For this purpose, according to Fig. 7 and Fig. 8 on the flat sides 9, 10 of the base support 1 facing the respective contact support 2, 3, a corresponding circumferential recess 15, 16 is provided, which is designed as a groove.

[0027] The cooling loops 21, 22 extend inwards towards each other, while the sections 52, 53 of the cooling elements 11, 12 connecting them further outwards extend essentially in a ring shape.

[0028] After Fig. 3 and Fig. 4 and 9 and 10, the cooling elements 11, 12 are each arranged in the corresponding recesses 15, 16 on the axial sides 9, 10 of the base support 1 such that the cooling loops 21, 22 are arranged for cooling the inner sides 7, 8 of the contact supports 2, 3 in the area of ​​the sliding contacts 4, 5 mounted on the outer side thereof. The recesses 15, 16 are designed with loops 46, 47 arranged on the base support 1 corresponding to the cooling loops 21, 22 ( Fig. 7 to 10).

[0029] The sections 52, 53 of the cooling elements 11, 12 connecting the cooling loops 21, 22 run with the coolant channels 13, 14 further outwards in the edge region of the base carrier 1 in order to cool the contact carriers 2, 3 in the edge region ( Fig. 5 to 10).

[0030] To cool the three sliding contacts 4, 5 on the contact carriers 2, 3, the cooling elements 11, 12 are arranged, for example, with three cooling loops 21, 22 each in corresponding three loops 46, 47 of the recesses 15, 16 on the base carrier 1. This allows the heat generated on the outside of the respective contact carrier 2, 3 by the respective sliding contact 4, 5 to be dissipated directly to the respective inside 7, 8 of the respective contact carrier 2, 3 through the respective cooling loop 21, 22 on the base carrier 1. In this way, direct active cooling at the point of heat generation with high cooling performance is achieved.

[0031] After Fig. 3 to 6, the coolant channels 13, 14 each have a coolant inlet opening 23, 24 and a coolant outlet opening 25, 26, each designed as an axial through-bore extending from the base of the coolant channels 13, 14. For connection to the coolant supply of the base support 1, a coolant inlet nozzle 27, 28 and a coolant outlet nozzle 29, 30 are provided at the coolant inlet opening 23, 24 and at the coolant outlet opening 25, 26, respectively, on the axial rear side of the cooling elements 11, 12 intended for use on the base support 1. The nozzles 27, 28 and 29, 30 are each designed as one-piece, axially projecting coolant-carrying projections on the axial rear sides of the cooling elements 11, 12 and communicate with the through-bore of the coolant inlet opening 23, 24 or with the through-bore of the coolant outlet opening 25, 26 ( Fig. 3 to 6).

[0032] The coolant inlet nozzles 27, 28 and a coolant outlet nozzle 29, 30 each have an outer diameter that is significantly larger than their axial length. The nozzles 27, 28 each form an annular radial sealing surface 35, 36, 37, 38 on their outer diameter.

[0033] After Fig. 2 to 4 and 8, a coolant inlet opening 31 and a coolant outlet opening 32 are provided in the recesses 15, 16 at the base of the base support 1 for connecting the two coolant inlet nozzles 23, 24 and the two coolant outlet nozzles 25, 26. These are each designed as an axial through-bore between the axial surfaces 9, 10 on the base support 1 ( Fig. 3 and Fig. 4).

[0034] The cooling elements 11, 12 are each elastically pressed in a coolant-tight manner to the coolant connection of the coolant channel 13, 14 with the respective nozzles 27, 28, 29, 30 with the radial sealing surface 35, 36, 37, 38 formed on the outer diameter on the inner diameter of the coolant inlet opening 31 and on the inner diameter of the coolant outlet opening 32 on the base support 1.

[0035] Since the coolant inlet opening 31 and the coolant outlet opening 32 are each designed as a through-bore on the base support 1, a cooling element 11, 12 with the respective coolant inlet nozzle 27, 28 can be elastically pressed into the axial sides 9, 10 of the base support 1 at each end of the coolant inlet opening 31, and a cooling element 11 with the respective coolant outlet nozzle 29, 30 can be elastically pressed into the base support 1 in a coolant-tight manner at each end of the coolant inlet opening 31. In this way, the coolant inlet and outlet nozzles 27, 28, 29, 30 each form a coolant-tight plug for connecting the cooling channels 13, 14 on the base support 1.

[0036] Accordingly, the coolant supply for both cooling elements 11, 12 arranged on the axial sides 9, 10 of the base support 1 can be effected via a common coolant inlet opening 31 and a common coolant outlet opening 32 on the base support 1.

[0037] In this case, mounting stops (not shown) can be provided on the inner diameter of the coolant inlet opening 31 and the coolant outlet opening 32, which ensure that in particular the coolant inlet nozzles 27, 28 in the coolant inlet opening 31 and the coolant outlet nozzles 29, 30 in the coolant outlet opening 32 are arranged with their opposite inserted ends at a predetermined distance from each other, so that they can each communicate unhindered with a coolant inlet channel 33 or with a coolant outlet channel 34 on the base support 1 ( Fig. 3 and Fig. 4).

[0038] To ensure even distribution of the coolant in the cooling circuit of the cooling elements 11, 12, the size of the flow cross-section of the coolant channels 13, 14 can vary in sections. Preferably, in the shortest section 42, 43 of the coolant channels 13, 14, between the respective coolant inlet 23 and the respective coolant outlet 24 of the coolant channels 13, 14, the flow cross-sections are smaller than in the remaining channel length.

[0039] The cooling elements 11, 12 can be sealed with additional sealing compound or adhesive in the area of ​​the sealing surfaces 35, 36, 37, 38 to the base support 1 and / or in the area of ​​the sealing surfaces 17, 18, 19, 20 to the contact supports 2, 3, which are adjacent to the inner side 7, 8. It is also possible to weld the cooling elements 11, 12 to the base support 1 in the area of ​​the sealing surfaces 35, 36, 37, 38 and / or to the contact supports 2, 3 in the area of ​​the sealing surfaces 17, 18, 19, 20.

[0040] The coolant inlet opening 31 and the coolant outlet opening 32 each communicate in a central region located between their ends with a coolant inlet channel 33 and a coolant outlet channel 34, respectively, which are connected to a coolant inlet 39 and a coolant outlet 40 on the base support 1. Oil from the cooling oil circuit of the electric machine is preferably used as the coolant.

[0041] The contact carriers 2, 3 are Fig. 1 and Fig.2 can be connected to an electrical supply (not shown), in particular to the electrical system of a vehicle, via an electrical connection lug with electrical contacts formed integrally with the contact plates. Accordingly, the contact carriers 2, 3 are current-carrying, so that the electrical sliding contacts 4, 5 can each be electrically connected in a simple manner, preferably by means of a material bond, for example by soldering or welding, via connecting strands 48 and 49 connected to the respective contact plates 2, 3.

[0042] The electrical sliding contacts 4, 5 are arranged in holders 44, 45 on the axial outer sides of the contact carriers 2, 3 and are preferably designed as electrically conductive so-called brushes, which establish the electrical contact with a slip ring (not shown) arranged on the rotor shaft for the electrical power supply of the rotor.

[0043] For pressing the sliding contacts 4 and 5, pressure means 50 and 51, in particular spring means, preferably torsion springs, are provided on the outer sides of the contact carriers 2, 3. List of reference symbols 1 base support 2 contact carriers 3 contact carriers 4 sliding contact 5 sliding contact 6 passage opening 7 Inside 8 Inside 9 Surface, side 10 Surface, side 11 Cooling element 12 Cooling element 13 Coolant channel 14 Coolant channel 15 recess 16 recess 17 Sealing surface 18 Sealing surface 19 Sealing surface 20 Sealing surface 21 Cooling loop 22 Cooling loop 23 Coolant inlet opening, through hole on the cooling element 24 Coolant inlet opening, through hole on the cooling element 25 Coolant outlet opening, through hole on the cooling element 26 Coolant outlet opening, through hole on the cooling element 27 Coolant inlet nozzle, attachment 28 Coolant inlet nozzle, attachment 29 Coolant outlet nozzle, attachment 30 Coolant outlet nozzle, attachment 31 Coolant inlet opening, through hole on the base support, 32 Coolant drain hole, through hole on the base support, 33 Coolant inlet channel 34 Coolant drain channel 35 Sealing surface 36 Sealing surface 37 Sealing surface 38 Sealing surface 39 Coolant inlet on the base carrier 40 Coolant leak on the base carrier 41 Screw connection 42 Section of the cooling element 43 Section of the cooling element 44 Bracket 45 bracket 46 Loop 47 Loop 48 connecting wires 49 connecting wire 50 Pressure medium, torsion spring 51 Pressure element, torsion spring 52 Section of the cooling element 53 Section of the cooling element 54 open side of the cooling element 55 open side of the cooling element QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2019 100 729 B4

[0002]

Claims

[1] Transmission device for transmitting electrical current to a rotor of an electrical machine, with two contact carriers (2, 3), each carrying electrical sliding contacts (4, 5), and with at least one base carrier (1) arranged between the contact carriers (2, 3), against which the contact carriers (2, 3) rest at least in sections and which carries them, characterized by in that for cooling at least one contact carrier (2, 3) at least one separate cooling element (11, 12) is provided which is open on one side and through which coolant can flow, said cooling element being inserted into a corresponding recess (15, 16) on the surface (9, 10) of the base carrier (1) and being made of elastic material at least in sections to seal the open side (54, 55) of the cooling element (11, 12) from the adjacent contact carrier (2, 3). [2] Transmission device according to claim 1, characterized by that elastomer is provided as the material for the cooling element (11, 12). [3] Transmission device according to one of claims 1 or 2, characterized by that the cooling element (11, 12) is designed in the shape of a channel and forms a cooling circuit in which several cooling loops (21, 22) are arranged one behind the other in a plane, and is inserted into a recess (15, 16) designed as a groove on the base support (1). [4] Transmission device according to one of claims 1 to 3, characterized by that the cooling element (11, 12) forms a coolant channel (13, 14) open on one side. [5] Transmission device according to one of claims 1 to 4, characterized by that the cooling element (11, 12) forms flat sealing surfaces (17, 18, 19, 20) lying in one plane on the open side (54, 55), with which it rests elastically in a coolant-tight manner on the flat inner side (7, 8) of the contact carrier (2, 3). [6] Transmission device according to one of claims 3 to 5, characterized bythat the cooling element (11, 12) is arranged on the base support (1) with the cooling loops (21, 22) for cooling the inner side (7, 8) of the adjacent contact support (2, 3) in the region of the sliding contacts (4, 5) attached to the outer side of the contact support (2, 3). [7] Transmission device according to one of claims 1 to 5, characterized by in that the cooling element (11, 12) forms a coolant inlet opening (23, 24) with a coolant-carrying coolant inlet nozzle (27, 28) and a coolant outlet opening (25, 26) with a coolant-carrying coolant outlet nozzle (29, 30) for connecting the coolant to the coolant channel (13, 14), wherein the nozzles (27, 28, 29, 30) are each elastically pressed in a coolant-tight manner with a radial sealing surface (35, 36, 37, 38) formed on the outer diameter on the inner diameter of a coolant inlet opening (31) and on the inner diameter of a coolant outlet opening (32) on the base support (1). [8] Transmission device according to one of claims 1 to 7, characterized by in that, for cooling both contact carriers (2, 3), a separate cooling element (11, 12) is arranged in a corresponding recess (15, 16) on the sides (9, 10) of the base carrier (1) facing them in each case and is sealed on the open side (54, 55) of the cooling element (11, 12) by an adjacent contact carrier (2, 3). [9] Transmission device according to one of claims 1 to 8, characterized by that the coolant inlet opening (31) and the coolant outlet opening (32) are each designed as a through-bore on the base support (1), such that at each end of the coolant inlet opening (31) a cooling element (11, 12) with the respective coolant inlet nozzle (27, 28) and at each end of the coolant outlet opening (32) a cooling element (11) with the respective coolant outlet nozzle (29, 30) is pressed in in a coolant-tight manner. [10] Transmission device according to one of claims 1 to 8, characterized by that the cooling element (11, 12) is sealed with additional sealing compound or adhesive at least in the region of the sealing surfaces (35, 36, 37, 38) to the base support (1) and / or in the region of the sealing surfaces () to the contact support (2, 3) which bears against the respective inner side (7, 8) or is welded to the base support (1) and / or to the contact support (2, 3).

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