Electric drive system for a vehicle and shielding device for electromagnetically shielding electric or electronic components

Abstract

The present invention relates to an electric drive system for a vehicle and to a shielding device for electromagnetically shielding electric or electronic components. The shielding assembly comprises a housing part which defines a receiving space for receiving the electrical or electronic components with an access opening and has an electrically conductive contact structure arrangement in the region of a circumference of the access opening, and a cover which extends in a planar manner for closing the access opening of the housing part and has a metal layer; wherein the cover can be positioned on the housing part such that the metal layer closes the access opening and the metal layer and the contact structure arrangement of the housing part are in direct contact with one another.

Description

[0001] R. 415024

[0002] - 1 -

[0003] Description

[0004] title

[0005] Electric drive system for a vehicle and shielding device for electromagnetic shielding of electrical or electronic components

[0006] The present invention relates to an electric drive system for a vehicle and a shielding device for the electromagnetic shielding of electrical or electronic components.

[0007] State of the art

[0008] Vehicles powered entirely or partially by electricity feature a drive system with an electric motor that is kinematically coupled to at least one axle or wheel of the vehicle to drive it. Typically, an electrical energy storage device, such as a battery, serves as the electrical energy source for the motor, and the electric motor is electrically connected to the energy storage device via power electronics. These power electronics conduct high electrical currents. Due to the high currents flowing in the power electronics and the electric motor, measures for electromagnetic shielding are usually implemented. This includes shielding the various components of the drive system from each other as well as shielding the components from external interference.

[0009] German patent application DE 10 2021 204 119 A1 describes an alternative shielding device for the electromagnetic shielding of electrical or electronic components. The known shielding device comprises a cover for the housing part, wherein a perforated or grid-like or mesh-like metal insert is incorporated into the cross-section of the plastic cover R. 415024.

[0010] - 2 - is enclosed and is partially exposed on an outer surface of the lid.

[0011] Typically, a conductive connection between the cover and the housing for electromagnetic shielding, also known as EMC protection, is established using a large number of closely spaced screws.

[0012] Although the present invention and its underlying principles are explained herein with reference to electric drive systems of vehicles, it is not limited thereto. Rather, the invention can be used wherever electromagnetic shielding of electrical or electronic components is required.

[0013] Disclosure of the invention

[0014] The invention provides a shielding device for the electromagnetic shielding of electrical or electronic components with the features of claim 1 and an electric drive system for a vehicle with the features of claim 10.

[0015] According to a first aspect of the invention, a shielding assembly for the electromagnetic shielding of electrical or electronic components is provided. The shielding assembly comprises a housing part which defines a receiving space for receiving the electrical or electronic components with an access opening and has an electrically conductive contact structure arrangement in the region of the circumference of the access opening. Furthermore, the shielding assembly comprises a cover extending over a flat area for closing the access opening of the housing part. The cover has a metal layer. The cover can be positioned on the housing part such that the metal layer closes the access opening and the metal layer and the contact structure arrangement of the housing part are in direct contact with each other. R. 415024

[0016] - 3 -

[0017] According to a second aspect of the invention, an electric drive system for a vehicle is provided. The drive system comprises a housing, an electric machine housed in the housing, an electronics housing, and a power electronic circuit which is electrically connected to the electric machine. The housing and / or the electronics housing includes a shielding assembly according to the first aspect of the invention. For example, the housing in which the electric machine is housed can be formed wholly or partially by the housing part of the shielding assembly and closed by the cover. Similarly, the electronics housing in which the power electronic circuit, which may, for example, include an inverter circuit, is housed can be formed wholly or partially by the housing part of the shielding assembly and closed by the cover.

[0018] One of the ideas underlying the present invention is to shield an interior of a housing part by means of an electrically conductive metal plate or metal layer, wherein the shielding assembly is used, for example, in a high-voltage AC area, in particular for power electronics of an electric drive or drive system.

[0019] An advantage of the present invention is that the shielding assembly according to the invention can be closed and thus functioned without connecting elements such as screws or the like. This means that the shielding assembly can provide an electrically conductive contact between the metal layer of the cover and the housing part or the housing structure without additional components such as screws.

[0020] Furthermore, eliminating the fasteners allows for further weight and / or cost savings. Eliminating the fasteners, particularly screws, also eliminates the need for machining the housing and cover components for mounting them, thus removing, for example, casting thickenings or domes for mounting fasteners such as screws. The cover can, for example, be a solid sheet metal structure (R. 415024).

[0021] - 4 - be formed. Optionally, the metal layer can be flat or formed.

[0022] Advantageous designs and further developments result from the further sub-claims as well as from the description with reference to the figures in the drawing.

[0023] According to a further development of the invention, the housing part has a contact surface surrounding the access opening, wherein the contact structure arrangement has a plurality of projections extending from the contact surface, and wherein the cover can be positioned on the housing part such that the cover rests with an inner surface against the contact surface of the housing part, the end face or circumferential surface of the cover faces the projections, and the metal layer and the projections are in contact with each other. For example, the metal layer can rest against the projections when the cover is arranged at the access opening.

[0024] For example, a circumferential edge area of ​​the cover can be designed to be electrically conductive.

[0025] According to a further embodiment of the invention, the end face or circumferential surface has a projection relative to the protrusions. This allows the cover to be held more securely over its lifetime due to a spring effect of the metal layer. For example, the metal layer can have a certain excess projection relative to the protrusions distributed along the circumference of the access opening, so that the projection rests firmly against the protrusions, further improving the electrical connection between the protrusions and the metal layer.

[0026] According to a further embodiment of the invention, the end face or circumferential surface of the metal layer is sharply edged, so that the end face or circumferential surface cuts into the projections during assembly. In this way, a more reliable electrical contact can be provided by the cutting action. This means that the protrusion can have a sharply designed end area, which, when the cover is attached with its R. 415024

[0027] - 5 -

[0028] The inner surface rests against the mounting surface of the housing part and extends into the cross-section of the projections.

[0029] According to a further embodiment of the invention, the housing part and the contact structure arrangement are formed in one piece as a cast metal part. For example, the projections can be formed in one piece with the side walls of the housing part.

[0030] According to a further embodiment of the invention, the cover comprises a composite material consisting of a metal layer and at least one plastic layer. This allows for the optimization of the shielding assembly's NVH (noise, vibration, and harshness) properties. The composite material can, for example, alternate between a metal layer and a plastic layer, with the number of metal layers being equal to or different from the number of plastic layers. In particular, the metal layer can be arranged on the inner side of the cover within the composite material. Alternatively, the cover consists solely of the metal layer.

[0031] According to a further embodiment of the invention, each layer of the composite material extends across the entire surface corresponding to the planar covering. That is, the material of the layer can be completely and continuously extended or stretched out without any gaps or spaces.

[0032] According to a further embodiment of the invention, the circumference of the access opening, in particular the contact surface, is coated with a liquid sealant. This allows the sealing of the shielding assembly to be further improved by the liquid sealant. Furthermore, the liquid sealant can contribute to the mechanical securing of the cover.

[0033] According to a further embodiment of the invention, the shielding assembly consists of the housing part and the cover. R. 415024

[0034] - 6 -

[0035] Brief description of the drawings

[0036] The invention will now be explained with reference to the figures in the drawings. The figures show:

[0037] Fig. 1 shows a schematic sectional view of an electric drive system for a vehicle according to an embodiment of the invention;

[0038] Fig. 2 shows a schematic top view of a shielding assembly for electromagnetic shielding of electrical or electronic components according to a further embodiment of the invention;

[0039] Fig. 3 is a schematic sectional view of the shielding assembly from Fig. 2, which results from a section along line AA shown in Fig. 2; and

[0040] Fig. 4 shows a schematic detail view of the area marked by the letter Z of the shielding assembly shown in Fig. 3.

[0041] In the figures, the same reference symbols denote identical or functionally equivalent components, unless otherwise stated. The numbering of process steps is for clarity and generally does not imply a specific chronological order. In particular, several process steps can be performed simultaneously.

[0042] Description of the exemplary implementations

[0043] Further advantages, features and details of the invention will become apparent from the following description, in which various embodiments are described in detail with reference to the drawing.

[0044] Fig. 1 schematically shows an electric drive system 200 for a vehicle with a housing 205, an electric machine 210 housed in the housing 205, an electronics housing 215 and a power electronic circuit 220, which is electrically connected to the electric machine 210. R. 415024

[0045] - 7 - is. The electrical machine 210 is shown schematically in Fig. 1 and can be, for example, a three-phase machine.

[0046] As shown in Fig. 1, the electric machine 210 has a stator 211 and a rotor 212 rotatable relative to the stator 211, with a rotor shaft 213 which can be kinematically coupled to a wheel (not shown) of the vehicle. The electronics housing 215 can, for example, be arranged on an outer circumference of the housing 205, as shown in Fig. 1 by way of example only. It would also be conceivable, for example, that the electronics housing 215 is arranged on an end face of the housing 205 or at another location on the housing 205. The power electronic circuit 220 is shown in Fig. 1 only as a block and serves to convert the electrical voltage provided by an electrical energy storage device (not shown) into a form suitable for the machine 210, e.g., an alternating voltage, during motor operation of the electric machine 210.Conversely, it can be provided that the power electronic circuit 220 is configured to convert an alternating voltage generated by the electrical machine 210 into a direct voltage in generator mode in order to charge the electrical energy storage device.

[0047] The electric machine 210 and the power electronic circuit 220 can each generate relatively strong alternating electromagnetic fields. As shown purely by way of example and only schematically in Fig. 1, the housing 205 and the electronics housing 215 can therefore each have a shielding assembly 100. It is also conceivable that only the electronics housing 215 or the housing 205 has a shielding assembly 100. Optionally, other devices or components of the drive system 200 can be provided with or shielded by a shielding assembly 100, e.g., sensors, the electrical energy storage device, or similar. As shown schematically in Fig. 1 and in more detail in Figures 2 to 4, the shielding assembly 100 has a housing part 1 and a cover 2.The housing part 1 defines a receiving space 10 for receiving the electrical or electronic components with an access opening 11. R. 415024.

[0048] - 8 -

[0049] Fig. 2 shows a schematic top view of a shielding assembly 100 for electromagnetic shielding of electrical or electronic components according to a further embodiment of the invention.

[0050] The shielding assembly 100 comprises, by way of example, a housing part 1 and a cover 2. In particular, the shielding assembly 100 can consist of the housing part 1 and the cover 2.

[0051] The housing part 1 defines a receiving space 10 for receiving the electrical or electronic components with an access opening 11 and has an electrically conductive contact structure arrangement 13 in the area of ​​a circumference 11 A of the access opening 11.

[0052] The cover 2 extends across its entire surface to close the access opening 11 of the housing part 1. The cover 2 has a metal layer 21. The cover 2, which extends across its entire surface, can, for example, be implemented as a plate-shaped part. For example, a circumferential edge region of the cover 2 can be electrically conductive. Optionally, the metal layer 21 or the cover 2, or both, can be flat or shaped.

[0053] The cover 2 can be positioned on the housing part 1 such that the metal layer 21 closes the access opening 11 and the metal layer 21 and the contact structure arrangement 13 of the housing part 1 are in direct contact with each other. As shown in Fig. 2, the shielding assembly can be closed and is therefore functional without fasteners such as screws or the like. This means that the shielding assembly can provide an electrically conductive contact between the metal layer of the cover and the housing part or the housing structure without additional components such as screws. The cover 2 can, for example, be designed as a solid sheet metal structure.

[0054] For example, the housing part 1 can have a contact surface 1a surrounding the access opening 11, wherein the contact structure arrangement 13 has a plurality of projections 113 extending from the contact surface 1a. R. 415024

[0055] - 9 -

[0056] Optionally, the housing part 1 and the contact structure arrangement 13 can be formed in one piece as a cast metal part. For example, the projections 113 can be formed in one piece with the side walls of the housing part 1.

[0057] Fig. 3 shows a schematic sectional view of the shielding assembly 100 from Fig. 2, which results from a section along the line AA shown in Fig. 2.

[0058] The cover 2 can be positioned on the housing part 1 such that the cover 2 with an inner surface 2a contacts the contact surface 1a of the housing part.

[0059] The end face or circumferential surface 2s of the cover 2 can face the projections 113, and the metal layer 21 and the projections 113 can be in contact with each other. For example, the metal layer 21 can be in contact with the projections 113 when the cover 2 is at the access opening.

[0060] II is ordered.

[0061] Furthermore, the end face or circumferential surface 2s can have a projection relative to the protrusions 113. Thus, over its lifetime, the cover can be held more securely by a spring effect of the metal layer. For example, the metal layer 21 can have a certain excess projection relative to the protrusions 113 distributed along the circumference 11A of the access opening, so that the projection rests firmly against the protrusions, further improving the electrical connection between the protrusions and the metal layer.

[0062] Alternatively or additionally, the end face or circumferential surface 2s of the metal layer 21 can be sharp-edged, so that the end face or circumferential surface 2s cuts into the projections 113 during assembly. In this way, a more reliable electrical contact can be provided by the cutting action. This means that the protrusion can have a sharply shaped end region which, when the cover 2 rests with its inner surface against the contact surface of the housing part 1, extends into the cross-section of the projections 113. R. 415024

[0063] - 10 -

[0064] Optionally, the perimeter 11 A of the access opening 11, in particular the contact surface 1a, can have a liquid sealant (not shown).

[0065] Fig. 4 shows a schematic detail view of the area marked by the letter Z of the shielding assembly 100 shown in Fig. 3.

[0066] The cover 2 can, for example, comprise a composite material formed from a metal layer 21 and at least one plastic layer 22. The composite material can, for example, alternate between a metal layer 21 and a plastic layer 22, with the number of metal layers 21 being equal or different from the number of plastic layers 22. In particular, the metal layer 21 can be arranged on an inner surface of the cover 2 within the composite material. By way of example, the composite material in Fig. 4 is formed from two metal layers 21 and a plastic layer 22 arranged between them.

[0067] Furthermore, each layer of the composite material can extend across the entire surface corresponding to the covering layer 2. This means that the material of the metal layer 21 and the plastic layer 22 can be completely and continuously extended or stretched out without any gaps or spaces.

[0068] Alternatively, the cover 2 can consist of the single metal layer 21.

[0069] Although the present invention has been explained above by way of example embodiments, it is not limited to these, but can be modified in many ways. In particular, combinations of the preceding embodiments are also conceivable.

Claims

1. R. 415024 - 11 - Claims 1. Shielding assembly (100) for electromagnetic shielding of electrical or electronic components, comprising: a housing part (1) which defines a receiving space (10) for receiving the electrical or electronic components with an access opening (11) and has an electrically conductive contact structure arrangement (13) in the area of ​​a circumference (11 A) of the access opening (11); and a planar extending cover (2) for closing the access opening (11) of the housing part (1), which has a metal layer (21); wherein the cover (2) can be positioned on the housing part (1) such that the metal layer (21) closes the access opening (11) and the metal layer (21) and the contact structure arrangement (13) of the housing part (1) are in direct contact with each other.

2. Shielding assembly (100) according to claim 1, wherein the housing part (1) has a contact surface (1a) surrounding the access opening (11), wherein the contact structure arrangement (13) has a plurality of projections (113) extending from the contact surface (1a), and wherein the cover (2) can be positioned on the housing part (1) such that the cover (2) bears against the contact surface (1a) of the housing part (1) with an inner surface (2a), the end face or circumferential surface (2s) of the cover (2) is facing the projections (113) and the metal layer (21) and the projections (113) are in contact with each other. R. 415024 - 12 - 3. Shielding assembly (100) according to claim 2, wherein the end face or circumferential surface (2s) has a projection in relation to the projections (113).

4. Shielding assembly (100) according to claim 2 or 3, wherein the end face or circumferential surface (2s) of the metal layer (21) is sharp-edged, so that the end face or circumferential surface (2s) cuts into the projections (113) during assembly.

5. Shielding assembly (100) according to one of the preceding claims, wherein the housing part (1) and the contact structure arrangement (13) are formed in one piece as a cast metal part.

6. Shielding assembly (100) according to one of the preceding claims, wherein the cover (2) comprises a composite material which is formed from the metal layer (21) and at least one plastic layer (22).

7. Shielding assembly (100) according to claim 6, wherein each layer of the composite material extends over the entire surface corresponding to the planar extending cover (2).

8. Shielding assembly (100) according to one of the preceding claims, wherein the perimeter (11 A) of the access opening (11), in particular the contact surface (1 a), comprises a liquid sealant.

9. Shielding assembly (100) according to one of the preceding claims, wherein the shielding assembly (100) consists of the housing part (1) and the cover (2).

10. Electric drive system (200) for a vehicle, comprising: a housing (205); an electric machine (210) housed in the housing (205); an electronics housing (215); and a power electronic circuit (220) electrically connected to the R. 415024 - 13 - electrical machine (210) is connected; wherein the housing (205) and / or the electronics housing (215) has a shielding assembly (100) according to one of the preceding claims.

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