Contact bridge with integrated ring filter, electric drive system and manufacturing process for a contact bridge

Abstract

The present invention relates to a contact bridge (1) for electrically coupling a first electrical conductor (2) with a second electrical conductor (3) of an electric drive system (4) for a motor vehicle (5), comprising an electrically conductive contact line (6) with a first contact section (7) for electrically contacting the first electrical conductor (2) and a second contact section (8) spaced apart from the first contact section (7) for electrically contacting the second electrical conductor (3) and a bridge housing (9) for holding the contact line (6), wherein the first contact section (7) is arranged on a first housing side (10) of the bridge housing (9) and the second contact section (8) is arranged on a second housing side (11) of the bridge housing (9).An electrical ring filter (12) is arranged in the bridge housing (9), which surrounds the contact line (6), the bridge housing (9) being designed to seal an oil chamber (13) of a unit housing (14) of an electric machine (15) of the electric drive system (4). The invention further relates to an electric drive system (4) for a motor vehicle (5) and a method for manufacturing a contact bridge (1).

Description

[0001] The present invention relates to a contact bridge for electrically coupling a first electrical conductor to a second electrical conductor of an electric drive system for a motor vehicle. Furthermore, the invention relates to an electric drive system for a motor vehicle and a method for producing a contact bridge of an electrical machine system for a motor vehicle.

[0002] Known electric drive systems for motor vehicles have an electric motor that is controlled by power electronics to drive the motor vehicle. Power electronics often include a pulse-controlled inverter. Due to the high-frequency clocked switching of the power semiconductors in the pulse-controlled inverter for converting the direct current voltage of a motor vehicle's high-voltage battery into a three-phase alternating current voltage to operate the electric motor, a common-mode voltage is generated on the conductors of the three-phase connection between the pulse-controlled inverter and the electric motor, which is consequently also present in the electrical conductors in the stator.

[0003] At the same time, the arrangement of various conductive but mutually insulated components in the electrical machine, such as the conductors in the stator, the stator core, the rotor, and the housing, creates a series of capacitances. In a separately excited synchronous machine, the conductors in the rotor are also added.

[0004] When a high-frequency voltage is applied, the capacitances become conductive, driving unwanted currents through the conductive components. In the case of a rotor shaft bearing, for example, these currents can lead to damage and premature failure of the bearing. Therefore, such currents should be avoided whenever possible.

[0005] Furthermore, these currents can generate electromagnetic fields that represent interference fields for surrounding components and thus disrupt their operation or reduce their operational reliability. To comply with the legal limits for electromagnetic compatibility of the electric drive system, the field strength of interference fields must also be reduced accordingly. To reduce such undesirable or impermissible effects, means are required to reduce the common-mode voltage on the three-phase connection that causes them. Ring filters, such as toroidal cores, are often used for this purpose. Ring-wound cores consist of a relatively brittle magnetic material that forms a loop around the three conductors. In this way, asymmetrical currents in the three conductors can be dampened by electromagnetic coupling.

[0006] The toroidal core is electrically insulated from the three conductors and is provided, for example, as a separate component with insulation and mounted around the three conductors. Alternatively, toroidal cores are also integrated into a component that accommodates the conductors for assembly purposes. The use of toroidal cores to reduce the common-mode voltage is known, for example, from documents DE 10 2018 220 420 A1, DE 10 2019 116 362 A1, DE 10 2015 224 872 A1, and EP 2 407 982 A2.

[0007] It is also known to integrate pulse-controlled inverters and electrical machines into a common unit housing and to electrically couple them together via a contact bridge. To ensure proper operation of the electrical machine, it can be arranged in an oil chamber of the unit housing, with the pulse-controlled inverter being arranged in a dry chamber that is sealed off from the oil chamber. Such a dry chamber is referred to as an “electronics chamber” in the context of the invention. To establish the electrical connection, for example, electrical conductors of the pulse-controlled inverter can be led into the oil chamber and sealed so that the penetration of oil into the electronics chamber is prevented. The electrical conductors of the pulse-controlled inverter can then be electrically coupled to electrical conductors of the electrical machine arranged in the oil chamber via a contact bridge arranged in the oil chamber.

[0008] Known electric drive systems for motor vehicles have the disadvantage that assembly is very complex. Toroidal cores are sometimes arranged and secured to the three electrical conductors in a single assembly cut, for example, via a screw connection. Furthermore, during assembly, the electrical conductors of the pulse-controlled inverter must be inserted into the oil chamber and sealed. When the pulse-controlled inverter is disassembled, for example, during an inspection or when replacing a defective pulse-controlled inverter, the seal must always be re-established. This takes additional time and thus causes increased costs. Furthermore, the risk of seal failure is increased.

[0009] It is therefore an object of the present invention to eliminate, or at least partially eliminate, the disadvantages described above in a contact bridge for electrically coupling a first electrical conductor to a second electrical conductor of an electric drive system for a motor vehicle. In particular, it is an object of the present invention to provide a contact bridge, an electric drive system for a motor vehicle, and a method for producing a contact bridge that, in a simple and cost-effective manner, reduce the number of required assembly steps and / or ensure improved replacement of components and / or reduce the risk of oil penetrating from the oil chamber into the electronics chamber.

[0010] The above object is achieved by the patent claims. Accordingly, the object is achieved by a contact bridge for electrically coupling a first electrical conductor to a second electrical conductor of an electric drive system for a motor vehicle, having the features of independent claim 1, by an electric drive system for a motor vehicle, having the features of independent claim 9, and by a method for producing a contact bridge, having the features of independent claim 10. Further features and details of the invention emerge from the subclaims, the description, and the drawings.Features and details that are described in connection with the contact bridge according to the invention naturally also apply in connection with the electrical drive system according to the invention and the method according to the invention and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is or can always be made mutually.

[0011] According to a first aspect of the invention, the object is achieved by a contact bridge for electrically coupling a first electrical conductor to a second electrical conductor of an electric drive system for a motor vehicle. The contact bridge has an electrically conductive contact line with a first contact section for electrically contacting the first electrical conductor and a second contact section, spaced from the first contact section, for electrically contacting the second electrical conductor, and a bridge housing for holding the contact line, wherein the first contact section is arranged on a first housing side of the bridge housing and the second contact section is arranged on a second housing side of the bridge housing.

[0012] According to the invention, an electrical ring filter is arranged in the bridge housing, which surrounds the contact line, wherein the bridge housing is designed to seal off an oil chamber of an aggregate housing of an electrical machine of the electrical drive system.

[0013] The electrically conductive contact line extends through the bridge housing, so that the first contact section of the contact line is arranged on the first housing side and the second contact section of the contact line is arranged on the second housing side. The contact bridge preferably has three electrically conductive contact lines, which are held electrically separated from one another on the contact bridge. The three electrically conductive contact lines preferably extend parallel to one another. With such a contact bridge, a 3-phase pulse-controlled inverter and a 3-phase electrical machine can thus be electrically coupled to one another. The contact line can also be referred to as a "busbar," for example.

[0014] The first electrical conductor is preferably designed as an electrical conductor of an electrical machine of the electrical drive system. The second electrical conductor is preferably designed as an electrical conductor of a power electronics unit, such as a pulse-controlled inverter, of the electrical drive system.

[0015] To establish the electrical connection to the first electrical conductor, the first contact section preferably has a press-in bolt for insertion into a bore in the first electrical conductor and / or a nut for receiving a screw and / or a bore for passing through a bolt of the first electrical conductor or the like. To establish the electrical connection to the second electrical conductor, the second contact section preferably has a press-in bolt for insertion into a bore in the second electrical conductor and / or a nut for receiving a screw and / or a bore for passing through a bolt of the second electrical conductor or the like. The electrical contact between the first electrical conductor and the first contact section or between the second electrical conductor and the second contact section can also be achieved by means of sockets, terminals, clamping screws or the like.

[0016] The bridge housing is preferably manufactured as an injection-molded part, for example from a thermoplastic or a thermoset. Alternatively, the bridge housing can also be made from an elastomer, such as rubber, caoutchouc, or the like.

[0017] The bridge housing fulfills several technical functions. One technical function of the bridge housing is to hold the contact line. Preferably, the contact line is secured to the bridge housing in such a way that it is prevented from slipping or being pulled out of the bridge housing. The contact line can, for example, be overmolded by a wall of the bridge housing or glued to it.

[0018] Another technical function of the bridge housing is the accommodation of the electrical ring filter, which surrounds the contact line(s). The ring filter is preferably embedded in the bridge housing and thus protected from external influences. The electrical ring filter is preferably designed as a toroidal core. The toroidal core comprises wound, magnetically active material bent into a ring shape. The electrical ring filter allows asymmetrical currents in the contact line(s) to be dampened through electromagnetic coupling.

[0019] A further technical function of the bridge housing is to seal the oil chamber of the unit housing of the electric machine from the electronics chamber. Accordingly, the bridge housing is designed to seal a connection feedthrough between the oil chamber and the electronics chamber. This protects the second contact section from oil from the oil chamber. When dismantling the electric machine from the oil chamber and the power electronics from the electronics chamber, the contact bridge can remain on the unit housing so that the connection feedthrough remains sealed. The electrical couplings to be released or restored are required for each component of the electric drive system either only on the dry side, i.e. the side facing the electronics chamber, or only on the oil side, i.e. the side facing the oil chamber.

[0020] A contact bridge according to the invention has the advantage over conventional contact bridges that the assembly and disassembly of the electric drive system is significantly improved using simple means and in a cost-effective manner. By providing several technical functions, such as sealing the connection feedthrough between the oil chamber and the electronics chamber, holding the contact line, and integrating the electrical ring filter, assembly steps in final assembly as well as during maintenance and repair work can be avoided. Furthermore, a reliable seal between the oil chamber and the electronics chamber can be achieved, so that when the electric machine or the power electronics is replaced, the risk of contamination of the electronics chamber by oil from the oil chamber is significantly reduced. In this way, the operational reliability of an electric drive system can be improved.

[0021] According to a preferred further development of the invention, a contact bridge can be provided with a circumferential first sealing device arranged on the contact line, wherein the first sealing device seals a circumferential gap between the contact line and the bridge housing. The first sealing device can be designed, for example, as a rubber seal, silicone seal, shrink tube or the like. The sealing device can be arranged on the contact line, for example, by injection molding, application, shrinking or the like. The circumferential gap between the bridge housing and the contact line can occur due to manufacturing tolerances. A circumferential design of the gap is also understood within the scope of the invention to mean that the gap can be interrupted at some points. Furthermore, the gap can have different gap heights.The sealing device allows the gap to be filled in such a way that oil penetration is prevented. This reduces the risk of contamination of the electronics compartment and thus damage to the power electronics. This has the advantage of improving the operational reliability of an electric drive system using simple and cost-effective means.

[0022] It is preferred according to the invention that the ring filter is arranged in a cavity of the bridge housing, wherein the cavity has a cavity opening on one side which is closed by a housing cover. The ring filter can be inserted into the cavity, for example, in a pre-assembly process for producing the contact bridge. The cavity can then be closed by the housing cover. Preferably, the cavity is sealed to the outside in this way, so that the ring filter is protected from external influences. The housing cover can be glued or welded to the bridge housing, for example. It is preferred according to the invention that the ring filter is held fixedly in the cavity by pressure from the housing cover. Preferably, the cavity opening is formed on the second housing side, which faces the electronics compartment in the installed state.The sealing surface between the housing cover and the bridge housing is thus located in the dry electronics compartment and not in the wet oil compartment. This has the advantage that, in the event of a faulty seal between the housing cover and the bridge housing during operation, no oil can penetrate into the cavity and thus reach the ring filter, preventing the oil from damaging the ring filter. This ensures safe operation even in the event of a fault. This further improves the operational reliability of an electric drive system.

[0023] More preferably, the ring filter is arranged in the cavity with a positive fit. In the context of the invention, a positive fit arrangement is understood to mean, for example, that the ring filter contacts all sides of the cavity without pressure. This contact can be limited to a few contact points, contact lines and / or contact surfaces. The ring filter can be arranged in the cavity, for example, by being easily pushed in. In this case, the invention can provide for the ring filter to be arranged in the cavity with as little tension as possible, for example in a loose arrangement, in order not to weaken the magnetic properties of the ring filter. Due to the positive fit arrangement of the ring filter in the cavity, the relative position of the ring filter to the cavity can be precisely defined. In this context, it is preferred that the ring filter has an elastic casing which acts as a damper between the ring filter and an inner wall of the cavity.This has the advantage of ensuring a secure arrangement of the ring filter on the bridge housing using simple and cost-effective means. This further improves the operational reliability of an electric drive system.

[0024] In a particularly preferred embodiment of the invention, in a contact bridge, it can be provided that the ring filter is glued into the cavity. The adhesive can, for example, be introduced into the cavity before the ring filter is inserted. Alternatively or additionally, the adhesive can be arranged on the ring filter before insertion. The adhesive reduces the risk of the ring filter falling out of the cavity. Furthermore, it can be provided according to the invention that the housing cover is held to the ring filter and / or bridge housing by the adhesive. This has the advantage that a secure holding of the ring filter and the housing cover on the bridge housing is ensured using simple means and in a cost-effective manner. The operational reliability of an electric drive system can thus be further improved.

[0025] The bridge housing preferably has a circumferential second sealing device on the first housing side, wherein the second sealing device is designed to make sealing contact with the unit housing. The second sealing device is thus preferably designed as an axial seal. The contact bridge is thus preferably designed to contact a wall of the unit housing surrounding the connection feedthrough, which wall faces the electronics compartment, with the second sealing device and thus seal the connection feedthrough. The second sealing device is preferably designed as a rubber seal, silicone seal, or the like. The bridge housing preferably has a circumferential groove in which the second sealing device is arranged such that the second sealing device protrudes from the groove, thus ensuring contact with the wall of the electronics compartment by the second sealing device.Alternatively, the second sealing device can also be designed as a radial seal. This has the advantage of ensuring reliable sealing of the connection feedthrough by the contact bridge using simple and cost-effective means. This further improves the operational reliability of an electric drive system.

[0026] According to a preferred embodiment of the invention, a contact bridge can be provided with screw bushings extending from the first housing side to the second housing side for screwing the bridge housing to the unit housing. By inserting screws into the screw bushings and tightening the screws in conjunction with the unit housing, the contact bridge can be pressed against the unit housing. A possible second sealing device can be pressed against the wall of the unit housing, thereby improving the sealing of the connection bushing. This has the advantage that the contact bridge reliably seals the connection bushing using simple means and in a cost-effective manner. This further improves the operational reliability of an electric drive system.Furthermore, the screwing ensures particularly easy installation of the contact bridge on the unit housing.

[0027] Particularly preferably, the bridge housing has an alignment device on the first housing side for positively aligning the bridge housing with the unit housing. The alignment device is preferably designed for joining and mutually aligning with a counter-alignment device of the unit housing. The alignment device can, for example, have one or more positioning pins, which are designed to engage in a counter-alignment device of the unit housing, which has corresponding positioning holes, for mutual alignment. Alternatively or additionally, the alignment device can have one or more positioning holes, which are designed to receive positioning pins of the counter-alignment device for mutual alignment.This has the advantage of improving the secure positioning of the contact bridge on the connection leadthrough of the unit housing using simple and cost-effective means. This further improves the assembly of an electric drive system.

[0028] According to a second aspect of the invention, the object is achieved by an electric drive system for a motor vehicle. The electric drive system has an electric machine for driving the motor vehicle, power electronics for operating the electric machine, and a unit housing, wherein the unit housing has an oil chamber, an electronics chamber, and a connection opening between the oil chamber and the electronics chamber. The electric machine is arranged in the oil chamber, and the power electronics are arranged in the electronics chamber. According to the invention, the connection opening is closed by a contact bridge according to the invention such that the oil chamber is sealed off from the electronics chamber by the contact bridge, wherein the electric machine is electrically coupled to the power electronics via the contact bridge.

[0029] Preferably, the contact bridge is secured to a wall of the unit housing facing the electronics compartment, for example, by gluing, screwing, clamping, or the like. When gluing, an adhesive is preferred that can also be easily removed during maintenance. Accordingly, it is preferred that the contact bridge be pressed against the unit housing via the electronics compartment, thus creating a seal with the oil chamber.

[0030] The contact bridge preferably has three electrically conductive contact lines that extend through a wall of the bridge housing such that the first contact sections are located in the oil chamber and the second contact sections are located in the electronics chamber. Furthermore, the contact lines are preferably completely surrounded by the ring filter. Thus, the contact bridge provides an electrical coupling between the oil chamber and the electronics chamber, as well as a reduction in electromagnetic interference fields.

[0031] The first contact sections of the contact lines are preferably mechanically and electrically coupled to the first electrical conductors of the electrical machine. The second contact sections of the contact lines are preferably mechanically and electrically coupled to the second electrical conductors of the power electronics, such as a pulse-controlled inverter.

[0032] The electric drive system according to the invention provides all the advantages already described for a contact bridge according to the first aspect of the invention. Accordingly, the electric drive system according to the invention has the advantage over conventional electric drive systems that assembly and disassembly of the electric drive system are significantly improved using simple means and in a cost-effective manner. By providing several technical functions, such as sealing the connection feedthrough between the oil chamber and the electronics chamber, holding the contact line, and integrating the electrical ring filter, assembly steps in final assembly as well as during maintenance and repair work can be avoided.Furthermore, a reliable seal between the oil chamber and the electronics compartment can be achieved, significantly reducing the risk of contamination of the electronics compartment by oil from the oil chamber when replacing the electric motor or power electronics. This improves the operational reliability of an electric drive system.

[0033] According to a third aspect of the invention, the object is achieved by a method for producing a contact bridge. The method comprises: - Providing the contact line in an injection molding tool, - producing the bridge housing with a cavity in the injection molding tool such that the contact line is held by the bridge housing and extends between the first housing side and the second housing side, - Inserting the ring filter into the cavity, and - Close the cavity with the housing cover of the bridge housing.

[0034] Preferably, a plurality of contact lines, in particular three contact lines, are provided in the injection molding tool. The provision can take place, for example, by insertion, pushing in, or the like. Preferably, the provision takes place such that the first contact section and the second contact section are arranged in different regions on the injection molding tool into which no injection molding material is injected, so that the first contact section and the second contact section are designed for electrical coupling after the injection molding process. The contact lines are preferably arranged parallel to one another on the injection molding tool. Further preferably, the contact lines have a first sealing device in a region between the first contact section and the second contact section, which sealing device is overmolded by the bridge housing during the injection molding process.After the injection molding process, at least part of the first sealing device is arranged within a wall of the bridge housing.

[0035] The injection molding process also creates the cavity. The ring filter is inserted into the cavity and preferably secured there with an adhesive. Finally, the cavity is closed by the housing cover of the bridge housing. The housing cover is preferably held in place by a fit, latch, or clip. More preferably, the housing cover is secured to the cavity with the adhesive.

[0036] The method according to the invention for producing a contact bridge results in all the advantages that have already been described for a contact bridge according to the first aspect of the invention and for an electric drive system according to the second aspect of the invention. Accordingly, the method according to the invention for producing a contact bridge has the advantage over conventional methods that a contact bridge can be produced using simple means and in a cost-effective manner, by means of which the assembly and disassembly of an electric drive system is significantly improved. By providing several technical functions, such as sealing the connection feedthrough between the oil chamber and the electronics chamber, holding the contact line and integrating the electrical ring filter, assembly steps in final assembly as well as during maintenance and repair work can be avoided.Furthermore, a reliable seal between the oil chamber and the electronics compartment can be achieved, significantly reducing the risk of contamination of the electronics compartment by oil from the oil chamber when replacing the electric motor or power electronics. This improves the operational reliability of an electric drive system.

[0037] A contact bridge according to the invention for electrically coupling a first electrical conductor to a second electrical conductor of an electric drive system for a motor vehicle, an electric drive system according to the invention for a motor vehicle, and a method according to the invention for producing a contact bridge are explained in more detail below with reference to the drawings. They each show schematically: Fig. 1 in a perspective sectional view of a contact bridge according to a preferred first embodiment of the invention, Fig. 2 in another perspective sectional view the contact bridge from Fig. 1, Fig. 3 shows a perspective sectional view of a contact bridge according to a preferred second embodiment of the invention, Fig. 4 in another perspective sectional view the contact bridge from Fig. 3, Fig. 5 shows a sectional view of a preferred embodiment of an electric drive system according to the invention, Fig. 6 shows a side view of a preferred embodiment of a motor vehicle with an electric drive system according to the invention, and Fig. 7 shows a flow chart of a preferred embodiment of a method according to the invention.

[0038] Elements with the same function and mode of action are listed in the Fig. 1 to 7 are each provided with the same reference numerals.

[0039] In the Fig. 1 and Fig. 2, a contact bridge 1 according to a preferred first embodiment of the invention is shown schematically in sectional views from different perspectives. The contact bridge 1 has a bridge housing 9 with a first housing side 10 and a second housing side 11 opposite the first housing side 10. The first housing side 10 faces an only indicated oil chamber 13 of a unit housing 14. The second housing side 11 faces an only indicated electronics chamber 23 of the unit housing 14. A cavity 17 is formed in the bridge housing 9, in which a ring filter 12 is arranged and fixed by an adhesive. The cavity 17 has a cavity opening which is closed by a housing cover 18.

[0040] The ring filter 12 surrounds three contact lines 6 of the contact bridge 1, which extend through the bridge housing 9 and are sealed to the bridge housing 9 via a first sealing device 16, so that oil flow from the first housing side 10 to the second housing side 11 along the contact lines 6 is prevented. The contact lines 6 have a first contact section 7 on the first housing side 10 and a second contact section 8 on the second housing side 11.

[0041] The contact bridge 1 is arranged on a connecting opening 24 of the unit housing 14 formed between the oil chamber 13 and the electronics chamber 23 such that the first housing side 10 contacts the unit housing 14. A second sealing device 19 arranged on the first housing side 10 contacts the unit housing 14 such that the electronics chamber 23 is sealed from the oil chamber 13. The second sealing device 19 is designed as an axial seal.

[0042] As from Fig. As can be seen from Figure 2, the bridge housing 9 has a pin-shaped alignment device 21 on the first housing side 10 for aligning the contact bridge 1 with the unit housing 14. For screwing the contact bridge 1 to the unit housing 14, the bridge housing 9 has several screw bushings 20. By tightening screws arranged in the screw bushings 20, the contact pressure of the second sealing device 19 can also be changed.

[0043] Fig. 3 and Fig. 4 show a contact bridge 1 according to a preferred second embodiment of the invention schematically in sectional views from different perspectives. The preferred second embodiment of the invention differs from that shown in Fig. 1 and Fig. 2, in an arrangement of the second sealing device 19. According to the second embodiment of the invention, the second sealing device 19 is arranged between the first housing side 10 and the second housing side 11. The second sealing device 19 is thus designed as a radial seal. The contact pressure of the second sealing device 19 cannot be changed by tightening the screws arranged in the screw passages 20.

[0044] In Fig. Figure 5 shows a schematic sectional view of a preferred embodiment of an electric drive system 4 according to the invention. The electric drive system 4 has a unit housing 14, through which an oil chamber 13 and an electronics chamber 23 are formed. Between the oil chamber 13 and the electronics chamber 23, a connecting opening 24 is arranged, which is sealed by a contact bridge 1 according to the invention. The first housing side 10 of the bridge housing 9 of the contact bridge 1 faces the oil chamber 13. The second housing side 11 of the bridge housing 9 faces the electronics chamber 23.

[0045] An electric machine 15 of the electric drive system 4 with three first electrical conductors 2 is arranged in the oil chamber 13. The three first electrical conductors 2 are each mechanically and electrically coupled to a first contact section 7 of the contact bridge 1. Power electronics 22 of the electric drive system 4 with three second electrical conductors 3 are each mechanically and electrically coupled to a second contact section 8 of the contact bridge 1. Thus, the electric machine 15 is electrically coupled to the power electronics 22 via the contact bridge 1.

[0046] Fig. Figure 6 shows a preferred embodiment of a motor vehicle 5 with an electric drive system 4 according to the invention, schematically in a side view. The electric drive system 4 has a unit housing 14 in which an electric machine 15, power electronics 22, and a contact bridge 1 are arranged.

[0047] In Fig.Figure 7 schematically shows a preferred embodiment of a method according to the invention for producing a contact bridge 1 according to the invention in a flow diagram. In a first method step 100, a contact line 6 is provided in an injection molding tool. Preferably, three contact lines 6 are provided in the injection molding tool, preferably aligned next to one another and parallel to one another. In a second method step 200, a bridge housing 9 of the contact bridge 1 with the first housing side 10 and the second housing side 11 is produced in the injection molding tool. In this case, a cavity 17 with a cavity opening formed on the second housing side 11 is produced. The cavity 17 completely surrounds the contact line 6.The injection molding process is carried out in such a way that the contact line 6 is held by the molded-on bridge housing 9 and extends between the first housing side 10 and the second housing side 11, wherein the first contact section 7 of the contact line 6 is arranged on the first housing side 10 and the second contact section 8 of the contact line 6 is arranged on the second housing side 11.

[0048] In a third process step 300, the ring filter 12 is inserted into the cavity 17. Thus, the ring filter 12 completely surrounds the contact line 6 or the contact lines 6. Preferably, the ring filter 12 is fixed in the cavity 17 with adhesive. In a fourth process step 400, the housing cover 18 is placed over the cavity opening of the cavity 17 and fixed in place. Thus, the cavity 17 is closed and the ring filter 12 is protected from external influences. List of reference symbols 1 contact bridge 2 first electrical conductor 3 second electrical conductor 4 electric drive system 5 Motor vehicle 6 contact line 7 first contact section 8 second contact section 9 bridge housing 10 first side of the housing 11 second housing side 12 ring filters 13 Oil room 14 Unit housing 15 electric machine 16 first sealing device 17 Cavity 18 Housing cover 19 second sealing device 20 screw feedthrough 21 Alignment device 22 Power electronics 23 Electronics room 24 Connection breakthrough 100 first procedural action 200 second procedural action 300 third procedural action 400 fourth procedural action 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 2018 220 420 A1

[0006] DE 10 2019 116 362 A1

[0006] DE 10 2015 224 872 A1

[0006] EP 2 407 982 A2

[0006]

Claims

[1] Contact bridge (1) for electrically coupling a first electrical conductor (2) to a second electrical conductor (3) of an electric drive system (4) for a motor vehicle (5), comprising an electrically conductive contact line (6) with a first contact section (7) for electrically contacting the first electrical conductor (2) and a second contact section (8) spaced apart from the first contact section (7) for electrically contacting the second electrical conductor (3), and a bridge housing (9) for holding the contact line (6), wherein the first contact section (7) is arranged on a first housing side (10) of the bridge housing (9) and the second contact section (8) is arranged on a second housing side (11) of the bridge housing (9), characterized bythat an electrical ring filter (12) is arranged in the bridge housing (9), which surrounds the contact line (6), wherein the bridge housing (9) is designed to seal off an oil chamber (13) of an aggregate housing (14) of an electrical machine (15) of the electrical drive system (4). [2] Contact bridge (1) according to claim 1, characterized by that a circumferential first sealing device (16) is arranged on the contact line (6), wherein the first sealing device (16) seals a circumferential gap between the contact line (6) and the bridge housing (9). [3] Contact bridge (1) according to claim 1 or 2, characterized by that the ring filter (12) is arranged in a cavity (17) of the bridge housing (9), wherein the cavity (17) has a cavity opening on one side which is closed by a housing cover (18). [4] Contact bridge (1) according to claim 3, characterized bythat the ring filter (12) is arranged in a form-fitting manner in the cavity (17). [5] Contact bridge (1) according to claim 3 or 4, characterized by that the ring filter (12) is glued into the cavity (17). [6] Contact bridge (1) according to one of the preceding claims, characterized by that the bridge housing (9) has a circumferential second sealing device (19) on the first housing side (10), wherein the second sealing device (19) is designed for sealing contact with the unit housing (14). [7] Contact bridge (1) according to one of the preceding claims, characterized by that the bridge housing (9) has screw bushings (20) extending from the first housing side (10) to the second housing side (11) for screwing the bridge housing (9) to the unit housing (14). [8] Contact bridge (1) according to one of the preceding claims, characterized bythat the bridge housing (9) has an alignment device (21) on the first housing side (10) for the positive alignment of the bridge housing (9) to the unit housing (14). [9] Electric drive system (4) for a motor vehicle (5), comprising an electric machine (15) for driving the motor vehicle (5), power electronics (22) for operating the electric machine (15) and an aggregate housing (14), wherein the aggregate housing (14) has an oil chamber (13), an electronics chamber (23) and a connecting opening (24) between the oil chamber (13) and the electronics chamber (23), wherein the electric machine (15) is arranged in the oil chamber (13) and the power electronics (22) is arranged in the electronics chamber (23), characterized bythat the connection opening (24) is closed by a contact bridge (1) according to one of the preceding claims such that the oil chamber (13) is sealed off from the electronics chamber (23) by the contact bridge (1), wherein the electrical machine (15) is electrically coupled to the power electronics (22) via the contact bridge (1). [10] Method for producing a contact bridge (1) according to one of claims 1 to 8, comprising: - Providing the contact line (6) in an injection molding tool, - producing the bridge housing (9) with a cavity (17) in the injection molding tool such that the contact line (6) is held by the bridge housing (9) and extends between the first housing side (10) and the second housing side (11), - Inserting the ring filter (12) into the cavity (17), and - Closing the cavity (17) with the housing cover (18) of the bridge housing (9).

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