Transmission device for transmitting electric current to rotor of electric machine

Abstract

The invention relates to a transmission device for transmitting an electric current to a rotor of an electric machine, comprising two contact carriers (2, 3), each carrying an electric sliding contact (4, 5), and at least one base frame (1) arranged between the contact carriers (2, 3), the contact carriers (2, 3) at least partially resting on the base frame and the base frame carrying the contact carriers, characterized in that the contact carriers (2, 3) are arranged on the base frame (1). In order to cool the at least one contact carrier (2, 3), at least one separate cooling element (11, 12) through which a cooling medium can flow and which is open on one side is provided, which cooling element is inserted into a counter-recess (15, 16) on the surface (9, 10) on the base frame (1) and is at least partially made of an elastic material in order to seal the open side (54, 55) of the cooling element (11, 12) from the contact carrier (2, 3) lying against the base frame (1).

Description

Technical Field

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

[0002] DE 10 2019 100 729 B4 discloses a brush module for a slip ring system of a current-excited electric motor of a motor vehicle, the brush module being used to energize the rotor of the electric motor. To dissipate heat from the brush module, a heat-conducting core is provided in a holding device for holding a brush holder. Summary of the Invention

[0003] The object of the present invention is therefore to provide a transmission device of the aforementioned type which ensures, in a structurally simple manner, operationally reliable cooling of electrical sliding contacts for transmitting current to an electric machine.

[0004] This object is achieved by the features of claim 1. Further advantageous claimed embodiments emerge from the corresponding dependent claims, the description and the drawings.

[0005] Therefore, a transmission device for transmitting current to the rotor of an electric motor is proposed. The transmission device includes two contact carriers and at least one base carrier arranged between the contact carriers. Each contact carrier carries an electrical sliding contact. The contact carriers at least partially rest against the base carrier and support the contact carriers. To cool the at least one contact carrier, at least one separate cooling element, open on one side and through which a coolant can flow, is provided. The cooling element is inserted into a corresponding recess in a surface of the base carrier and is at least partially made of an elastic material to seal the open side of the cooling element from the resting contact carrier.

[0006] In this way, active cooling of the contact carrier can be achieved with high cooling efficiency by simply embedding the cooling element on the surface of the base carrier. The cooling element can be designed as a simple insert or a simple insertion part.

[0007] The elastic properties of the cooling element enhance the sealing effect, enabling reliable sealing of the cooling element, particularly through the contact holder resting on the open side of the cooling element and the connection of the cooling element to the base frame. This reliably prevents localized coolant leaks. Furthermore, component tolerances on the resting contact holder and base frame can be compensated, particularly at the connection of the cooling element. This allows for simple and cost-effective production of the base frame, for example, by casting.

[0008] In a preferred embodiment of the invention, an elastomer is provided as the material of the cooling element, whereby the cooling element can be produced particularly simply and cost-effectively, in particular by casting.

[0009] Another refinement of the present invention is that the cooling element is designed in the form of a groove and forms a cooling circuit in which a plurality of cooling curves are arranged one behind the other in a plane. This allows the cooling element to be inserted into a recess, preferably a groove, on a base frame, preferably in the form of a plate, in a particularly space-saving manner. This is particularly applicable when the contact carrier resting on the base frame is designed in the form of a plate.

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

[0011] In another preferred embodiment of the invention, the cooling element forms a flat sealing surface on the open side, which lies in one plane and by means of which the cooling element rests elastically in a coolant-tight manner on the flat inner side of the contact carrier.

[0012] In another advantageous embodiment of the present invention, cooling elements are preferably arranged in corresponding recesses with cooling bends on the base frame to cool the inner side of the contact carrier in contact with the sliding contacts mounted on the outer side of the contact carrier. This arrangement enables particularly effective and targeted cooling at the locations where heat is generated that needs to be dissipated.

[0013] A particularly simple connection of the coolant connection of the coolant channel to the coolant supply of the base carrier can be achieved in that the cooling element preferably forms a coolant inlet with a coolant inlet connection for conducting the coolant and a coolant outlet with a coolant outlet connection for conducting the coolant, wherein the connections are elastically pressed with their radial sealing surfaces formed on their outer diameters onto the inner diameter of the coolant inlet on the base carrier and onto the inner diameter of the coolant outlet on the base carrier in a coolant-tight manner.

[0014] In another particularly preferred development, two separate cooling elements are provided for cooling the two contact holders. Preferably, a separate cooling element is arranged in a corresponding recess on the side of the base carrier facing the contact holders, and the cooling element is sealed on the open side of the cooling element by the contact holders resting against each other.

[0015] Preferably, the coolant inlet and the coolant outlet are each implemented as a through-hole on the base frame, whereby a corresponding coolant inlet connection of the cooling element is elastically pressed in at each end of the coolant inlet in a coolant-tight manner, and a corresponding coolant outlet connection of the cooling element is elastically pressed in at each end of the coolant outlet in a coolant-tight manner.

[0016] The coolant connections of the two cooling elements on the base frame can thus be realized jointly via a coolant inlet and a coolant outlet, each of which is designed as a through-hole on the base frame.

[0017] It is also advantageous if mounting stops are provided on the inner diameter of the coolant inlet and coolant outlet on the base frame, respectively, for contact with the respective ends of the respectively inserted coolant inlet and coolant outlet connectors. This allows the cooling element to be precisely positioned in the coolant inlet and coolant outlet on the base frame via the connectors.

[0018] To ensure uniform distribution of the coolant in the cooling circuit of the cooling element, the size of the flow cross-section of the coolant channels formed on the cooling element can be varied locally. Preferably, a coolant channel with a smaller flow cross-section than the remaining channel profile is formed in the shortest coolant channel section between the coolant inlet and the coolant outlet.

[0019] Another possible embodiment of the present invention is that the respective cooling element is sealed with an additional sealing block or adhesive at least in the region of the sealing surface relative to the base frame and / or relative to the sealing surface of the contact holder that is respectively in contact with the inner side. Alternatively, the respective cooling element can be welded to the base frame and / or to the respective contact holder at least in the region of the sealing surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features of the invention claimed for protection are apparent from the following description and the accompanying drawings which further illustrate the invention.

[0021] Figure 1 and Figure 2 shows a side view of a transmission device according to the invention for transmitting current to a rotor of an electric machine,

[0022] Figure 3 and Figure 4 shows the transmission device along Figure 1 The cross section of the cutting lines AA and BB,

[0023] Figure 5 and Figure 6 shows a single perspective view of a cooling element of a transmission device,

[0024] Figure 7 and Figure 8 shows a side view of a base frame of the transport device,

[0025] Figure 9 and Figure 10 A side view of the base frame is shown with corresponding cooling elements and the position of the sliding contacts of the contact holder (indicated by dashed lines). DETAILED DESCRIPTION

[0026] The figures show, by way of example, various views of a transmission device for transmitting electric current to a rotor of an electric machine.

[0027] according to Figures 1 to 4 and Figures 7 to 10 The transmission device comprises an integral base frame 1 and two contact supports 2 and 3. Each contact support carries three electrical sliding contacts 4 and 5, respectively, for transmitting current to a rotor (not shown). The base frame 1 is coaxially arranged between the contact supports 2 and 3, providing support and electrical insulation. The base frame 1 and the contact supports 2 and 3 form a central through-hole 6 in the fixedly arranged transmission device. The central through-hole is used to axially pass the shaft (not shown) of the motor that carries the rotor.

[0028] The base frame 1 and the contact holders 2 and 3 are each plate-shaped. The contact holders are preferably designed as circular contact plates, and their flat inner sides 7 and 8, which face the base frame 1 in the axial direction, are fastened to the mutually facing axial sides 9 and 10 of the base frame 1, for example, via axial screw connections. The transmission device can be fastened to a stationary component, such as the stator housing of an electric motor, via further axial screw connections 41. Three electrical sliding contacts 4 and 5, for example, are arranged evenly distributed around the circumference on the mutually facing axial outer sides of the contact holders 2 and 3 and are fastened to the contact holders 2 and 3 in holders 44 and 45.

[0029] according to Figure 1 、 Figure 2 、 Figures 4 to 8 In order to cool the contact supports 2, 3 and dissipate the heat generated by the electric sliding contacts 4, 5 during operation, two separate cooling elements 11, 12 of identical structure are provided. The cooling elements 11, 12 are each made of an elastic material, preferably an elastomer, and are each formed with a cooling medium channel 13, 14 open on one side to allow the cooling medium to flow through. The cooling medium channels 13, 14 are each implemented as a groove on the front side of the cooling elements 11, 12 and form a U-shaped cross-sectional profile ( Figure 3 and Figure 4The cooling elements 11 , 12 are inserted with the open sides 54 , 55 of the coolant channels 13 , 14 pointing axially outwards into corresponding recesses 15 , 16 on the axial sides 9 , 10 of the base frame 1 facing the respective contact carrier 2 , 3 .

[0030] On the respective open sides 54, 55 of the coolant channels 13, 14, the cooling elements 11, 12 form flat axial sealing surfaces 17, 18 or 19, 20, via which the cooling elements rest in an axially elastic, coolant-tight manner on the flat inner sides 7, 8 of the contact holders 2, 3, whereby the coolant channels 13, 14 are sealed at the respective open sides 54, 55 by the resting contact holders 2, 3 ( Figure 3 and Figure 4 The elastic contact improves the sealing effect of the contact holders 2, 3 respectively resting on the open sides 54, 55. By screwing the contact holders 2, 3 to the base frame 1, the cooling elements 11, 12 are axially retained in the corresponding recesses 15, 16 and are covered by the contact holders 2, 3 respectively resting on the open sides 54, 55. They are elastically pressed against the contact holders 2, 3 via the axial sealing surfaces 17, 18 or 19, 20.

[0031] according to Figure 5 and Figure 6 , the cooling elements 11, 12 are each designed in the shape of a groove. The cooling elements each form a cooling circuit in which a plurality of cooling bends 21, 22 arranged one behind the other are arranged in one plane, so that the cooling elements 11, 12 can be mounted on a flat side 9, 10 of the plate-shaped base frame 1, respectively. For this purpose, as Figure 7 and Figure 8 As shown, corresponding circumferential recesses 15 , 16 , which are designed as grooves, are provided on the flat sides 9 , 10 of the base frame 1 , which face the respective contact carrier 2 , 3 .

[0032] The cooling bends 21 , 22 extend inwardly toward one another, while the sections 52 , 53 of the cooling elements 11 , 12 , each connecting the cooling bends, extend further outwardly essentially in an annular manner.

[0033] according to Figure 3 and Figure 4 as well as Figure 9 and Figure 10 , the cooling elements 11, 12 are arranged in corresponding recesses 15, 16 on the axial sides 9, 10 of the base frame 1, respectively, so that the cooling bends 21, 22 are arranged in the region of the sliding contacts 4, 5 mounted on the outer sides of the contact holders, respectively, to cool the inner sides 7, 8 of the contact holders 2, 3. Here, the recesses 15, 16 are embodied on the base frame 1 with bends 46, 47 ( Figures 7 to 10 ).

[0034] The sections 52, 53 of the cooling elements 11, 12 connecting the cooling bends 21, 22 together with the coolant channels 13, 14 extend further outwards in the edge region of the base frame 1 in order to cool the contact carriers 2, 3 in the edge region. Figures 5 to 10 ).

[0035] To cool the three sliding contacts 4, 5 on each of the contact holders 2, 3, the cooling elements 11, 12 are arranged, for example, with three cooling bends 21, 22 in three corresponding bends 46, 47 of the recesses 15, 16 on the base frame 1. As a result, the heat generated on the outer sides of the respective contact holders 2, 3 by the respective sliding contacts 4, 5 can be dissipated directly to the respective inner sides 7, 8 of the respective contact holders 2, 3 via the corresponding cooling bends 21, 22 on the base frame 1. This achieves direct active cooling at the heat generation locations with high cooling efficiency.

[0036] according to Figures 3 to 6 The cooling medium channels 13 and 14 respectively have a cooling medium inlet 23 and 24 and a cooling medium outlet 25 and 26, which are respectively implemented as axial through-holes starting from the bottom of the cooling medium channels 13 and 14. In order to connect to the cooling medium supply part of the base frame 1, cooling medium inlet joints 27 and 28 and cooling medium outlet joints 29 and 30 are respectively provided at the cooling medium inlets 23 and 24 and the cooling medium outlets 25 and 26 at the axial rear side of the cooling elements 11 and 12 for installation on the base frame 1. The joints 27, 28 or 29, 30 are respectively implemented as an integrated projection for guiding the cooling medium, which protrudes axially vertically at the axial rear side of the cooling elements 11 and 12 and is connected to the through-holes of the cooling medium inlets 23 and 24 or the through-holes of the cooling medium outlets 25 and 26 ( Figures 3 to 6 ).

[0037] The outer diameter of cooling medium inlet joint 27,28 and cooling medium discharge joint 29,30 is obviously greater than its axial length. Here, joint 27,28 forms annular radial sealing surface 35,36,37,38 at its outer diameter place respectively.

[0038] according to Figures 2 to 4 and Figure 8 In order to connect the two coolant inlet connections 23, 24 and the two coolant outlet connections 25, 26 to the base frame 1, a coolant inlet 31 and a coolant outlet 32 ​​are provided at the bottom of the recesses 15, 16. The coolant inlet and the coolant outlet are each implemented as an axial through hole ( Figure 3 and Figure 4 ).

[0039] Here, the cooling elements 11, 12 are elastically pressed into the inner diameter of the coolant inlet 31 and the inner diameter of the coolant outlet 32 ​​on the base frame 1 in a coolant-tight manner, so that the coolant channels 13, 14 are connected to the corresponding connections 27, 28, 29, 30 with radial sealing surfaces 35, 36, 37, 38 formed on the outer diameter respectively.

[0040] Since the coolant inlet 31 and the coolant outlet 32 ​​are each designed as a through-hole in the base frame 1, a cooling element 11, 12 with a corresponding coolant inlet connection 27, 28 can be elastically pressed in at each end of the coolant inlet 31 and a cooling element 11 with a corresponding coolant outlet connection 29, 30 can be elastically pressed in at each end of the coolant outlet 32 ​​in a coolant-tight manner on the axial sides 9, 10 of the base frame 1. In this way, the coolant inlet and coolant outlet connections 27, 28, 29, 30 each form a coolant-tight plug for connecting the coolant channels 13, 14 to the base frame 1.

[0041] Thus, two cooling elements 11 , 12 , each arranged on an axial side 9 , 10 of the base frame 1 , can be supplied with cooling medium via a common cooling medium inlet 31 and a common cooling medium outlet 32 ​​on the base frame 1 .

[0042] Here, in the coolant inlet 31 and in the coolant outlet 32, respectively, a mounting stop (not shown) can be provided at the inner diameter, which ensures that in particular the coolant inlet connections 27, 28 in the coolant inlet 31 and the coolant outlet connections 29, 30 in the coolant outlet 32 ​​are arranged with their oppositely inserted ends at a predetermined distance from each other, so that they can respectively communicate unimpeded with the coolant inlet channel 33 and the coolant outlet channel 34 on the base frame 1 ( Figure 3 and Figure 4 ).

[0043] In order to distribute the coolant uniformly in the cooling circuits of the cooling elements 11, 12, the size of the flow cross sections of the coolant channels 13, 14 can be varied locally. Preferably, between the respective coolant inlet 23 and the respective coolant outlet 24 of the coolant channels 13, 14, a smaller flow cross section is formed in the respective shortest section 42, 43 of the coolant channels 13, 14 than in the remaining channel profiles.

[0044] The cooling elements 11, 12 can be sealed by an additional sealing compound or adhesive in the region of the sealing surfaces 35, 36, 37, 38 relative to the base frame 1 and / or in the region of the sealing surfaces 17, 18, 19, 20 relative to the contact holders 2, 3 resting against the inner sides 7, 8. Alternatively, the cooling elements 11, 12 can be welded to the base frame 1 in the region of the sealing surfaces 35, 36, 37, 38 and / or to the contact holders 2, 3 in the region of the sealing surfaces 17, 18, 19, 20.

[0045] The cooling medium inlet 31 and the cooling medium outlet 32 ​​are connected to a cooling medium inlet channel 33 or a cooling medium outlet channel 34 in the middle area between their ends, respectively. The cooling medium inlet channel or the cooling medium outlet channel is connected to a cooling medium inlet 39 and a cooling medium outlet 40 on the base frame 1. Oil from the cooling oil circuit of the motor is preferably used as the cooling medium.

[0046] according to Figure 1 and Figure 2 The contact carriers 2, 3 can each be connected to a power supply (not shown), in particular to the vehicle's onboard power supply, via an electrical connection lug with electrical contacts integrally formed therewith. The contact carriers 2, 3 can thus conduct current, so that the electrical sliding contacts 4, 5 can each be electrically connected in a simple manner, preferably by material connection, for example by soldering or welding, via a connecting wire 48 or 49 connected to the respective contact plate 2, 3.

[0047] The electrical sliding contacts 4 , 5 are arranged in holders 44 , 45 on the axial outside of the contact carriers 2 , 3 and are preferably designed as electrically conductive brushes, so-called brushes, which establish electrical contact with slip rings (not shown) arranged on the rotor shaft for power supply.

[0048] For pressing the sliding contact 4 or 5 , a pressing element 50 or 51 , in particular a spring element, preferably a torsion spring, is provided which is fastened to the outer side of the contact carrier 2 , 3 .

[0049] Reference Signs List

[0050] 1 Frame

[0051] 2 contact brackets

[0052] 3 contact brackets

[0053] 4 sliding contacts

[0054] 5 sliding contacts

[0055] 6 through holes

[0056] 7 Inside

[0057] 8 Inside

[0058] 9 Surface, side

[0059] 10 Surface, side

[0060] 11 Cooling element

[0061] 12 Cooling element

[0062] 13 Cooling medium channel

[0063] 14 Cooling medium channel

[0064] 15 concavity

[0065] 16 recess

[0066] 17 Sealing surface

[0067] 18 Sealing surface

[0068] 19 Sealing surface

[0069] 20 Sealing surface

[0070] 21 Cooling Bend

[0071] 22 Cooling Bend

[0072] 23 Cooling medium inlet, through hole on cooling element

[0073] 24 Cooling medium inlet, through holes on cooling elements

[0074] 25 Cooling medium outlet, through hole on cooling element

[0075] 26 Cooling medium outlet, through hole on cooling element

[0076] 27 Cooling medium enters the joint and protrusion

[0077] 28 Cooling medium enters the joint and protrusion

[0078] 29 Cooling medium discharge joint, protrusion

[0079] 30 Cooling medium discharge joint, protrusion

[0080] 31 Cooling medium inlet, through hole on the base frame

[0081] 32 Cooling medium outlet, through hole on the base frame

[0082] 33 Cooling medium inflow channel

[0083] 34 Cooling medium outflow channel

[0084] 35 Sealing surface

[0085] 36 Sealing surface

[0086] 37 Sealing surface

[0087] 38 Sealing surface

[0088] 39 Cooling medium inlet on the base frame

[0089] 40 Cooling medium outlet on the base frame

[0090] 41 spiral connection

[0091] 42 Cooling element segments

[0092] 43 Cooling element sections

[0093] 44 Maintaining part

[0094] 45 Maintaining part

[0095] 46 bends

[0096] 47 Bend

[0097] 48 Connecting strands

[0098] 49 Connecting strands

[0099] 50 press parts, rotary torsion spring

[0100] 51 Pressing piece, rotating torsion spring

[0101] 52 Cooling element segments

[0102] 53 Cooling element section

[0103] 54 Open side of cooling element

[0104] 55 Open side of cooling element

Claims

1. A transmission device for transmitting current to a rotor of an electric motor, comprising two contact supports (2, 3) and at least one base frame (1) arranged between the contact supports (2, 3), the contact supports each carrying an electric sliding contact (4, 5), the contact supports (2, 3) at least partially resting on the base frame, and the base frame carrying the contact supports, characterized in that In order to cool at least one contact holder (2, 3), at least one separate cooling element (11, 12) is provided, through which a cooling medium can flow and which is open on one side. The cooling element is inserted into a corresponding recess (15, 16) on a surface (9, 10) on the base frame (1), and in order to seal the open side (54, 55) of the cooling element (11, 12) to the contact holder (2, 3) in contact therewith, the cooling element is at least partially made of an elastic material.

2. The transmission device according to claim 1, characterized in that Elastomer is provided as the material of the cooling element (11, 12).

3. The transmission device according to claim 1 or 2, characterized in that The cooling elements (11, 12) are implemented in a groove shape and form a cooling circuit in which a plurality of cooling bends (21, 22) are arranged one after the other in a plane and are placed in recesses (15, 16) implemented as grooves on the base frame (1).

4. The transmission device according to any one of claims 1 to 3, characterized in that The cooling elements (11, 12) form cooling medium channels (13, 14) open on one side.

5. The transmission device according to any one of claims 1 to 4, characterized in that The cooling elements (11, 12) form flat sealing surfaces (17, 18, 19, 20) located in one plane on the open sides (54, 55), via which the cooling elements rest elastically and in a coolant-tight manner on the flat inner sides (7, 8) of the contact supports (2, 3).

6. The transmission device according to any one of claims 3 to 5, characterized in that The cooling elements (11, 12) are arranged on the base frame (1), and cooling bends (21, 22) are used in the region of sliding contacts (4, 5) mounted on the outer sides of the contact supports (2, 3) for cooling the inner sides (7, 8) of the contact supports (2, 3) in contact therewith.

7. The transmission device according to any one of claims 1 to 5, characterized in that The cooling elements (11, 12) form cooling medium inlets (23, 24) having cooling medium inlet joints (27, 28) for guiding the cooling medium and cooling medium outlets (25, 26) having cooling medium discharge joints (29, 30) for guiding the cooling medium to connect the cooling medium channels (13, 14), wherein the joints (27, 28, 29, 30) are elastically pressed onto the inner diameter of the cooling medium inlet (31) and the inner diameter of the cooling medium outlet (32) at the base frame (1) in a cooling medium-sealing manner through radial sealing surfaces (35, 36, 37, 38) formed on their outer diameters.

8. The transmission device according to any one of claims 1 to 7, characterized in that In order to cool the two contact supports (2, 3), a separate cooling element (11, 12) is arranged in a corresponding recess (15, 16) on the sides (9, 10) of the base frame (1) facing the two contact supports, and the cooling element (11, 12) is sealed on the open side (54, 55) by the contact supports (2, 3) abutting against each other.

9. The transmission device according to any one of claims 1 to 8, characterized in that The cooling medium inlet (31) and the cooling medium outlet (32) are respectively implemented as through holes on the base frame (1), so that at each end of the cooling medium inlet (31), the corresponding cooling medium inlet joints (27, 28) of the cooling elements (11, 12) are elastically pressed in in a cooling medium-sealed manner, and at each end of the cooling medium outlet (32), the corresponding cooling medium outlet joints (29, 30) of the cooling element (11) are elastically pressed in in a cooling medium-sealed manner.

10. The transmission device according to any one of claims 1 to 8, characterized in that The cooling elements (11, 12) are sealed at least in the region of the sealing surfaces (35, 36, 37, 38) relative to the base frame (1) and / or in the region of the sealing surfaces relative to the contact holders (2, 3) abutting against the corresponding inner sides (7, 8) with an additional sealing block or adhesive, or are welded to the base frame (1) and / or to the contact holders (2, 3).

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