GB2629171A

GB2629171A - Electric drive unit panel

Info

Publication number: GB2629171A
Application number: GB2305713.6A
Authority: GB
Inventors: Edwards Llyr
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2023-04-19
Filing date: 2023-04-19
Publication date: 2024-10-23
Also published as: GB202305713D0

Abstract

A panel 14 for an electric drive unit 24 comprising: a first and second layer 16,18; the first layer comprising an electrically conductive layer 20 configured to prevent, in use, at least a portion of electromagnetic radiation 22 produced by the electric drive unit from passing through the electrically conductive layer; and the second layer comprising an electrically non-conductive layer 26 configured to support the electrically conductive layer. Also claimed is an electric drive unit panel and a vehicle comprising the panel. The conductive layer may form part of a Faraday cage around the electric drive unit and may comprise a wire mesh. The first and second layers may be coextensive. The conductive layer may be embedded within the non-conductive layer and may comprise a plurality of holes 30, the largest dimension of the holes (32, Fig.5) sized to prevent desired frequency or frequencies passing through it. The largest dimension may be 2.5mm or 15mm. The panel may be attached to a housing 36 in an electrically conductive manner by means of at least one fastener. The electric drive unit may comprise a traction motor, a battery, a high voltage DC to DC converter or an inverter.

Description

ELECTRIC DRIVE UNIT PANEL

TECHNICAL FIELD

The present disclosure relates to an electric drive unit panel. In particular, but not exclusively it relates to an electric drive unit panel in a passenger vehicle.

BACKGROUND

Electric drive units produce electromagnetic radiation emissions during use. Electric drive units can be shielded to prevent/reduce transmission of the electromagnetic radiation produced.

It is an aim of the present invention to address one or more of the disadvantages associated

with the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide an electric drive unit panel, a vehicle component, and a vehicle as claimed in the appended claims.

According to an aspect of the invention there is provided an electric drive unit (EDU) panel comprising: a first and second layer; the first layer comprising an electrically conductive layer configured to prevent, in use, at least a portion of electromagnetic radiation produced by the electric drive unit from passing through the electrically conductive layer; and the second layer comprising an electrically non-conductive layer configured to support the conductive layer.

This provides the advantage that the EDU is shielded, and a weight and cost benefit is provided.

In some examples, the electrically conductive layer of the panel is configured to form at least part of a Faraday cage around the electric drive unit.

In some examples, the first and second layers are coextensive.

In some examples, the electrically conductive layer is embedded within the electrically nonconductive layer.

In some examples, the electrically conductive layer comprises a plurality of holes and wherein the largest dimension of the holes is less than a value determined in dependence on the frequency or frequencies of electromagnetic radiation at least a portion of which is to be prevented, in use, from passing through the electrically conductive layer.

This provides the advantage that further weight and cost saving is provided while still shielding the EDU.

In some examples, the largest dimension of the holes is in the range 2mm to 16mm.

In some examples, the largest dimension of the holes is 2.5mm or 15mm.

In some examples, the electrically conductive layer comprises a wire mesh.

In some examples, the panel is configured to be attached to a housing of the electric drive unit and wherein the panel is configured to allow, when attached to the housing, an electrically conductive path from the electrically conductive layer to the housing.

In some examples, the electrically conductive layer of the panel is configured to close at least an end of the housing to complete a Faraday cage around the electric drive unit, when the panel is attached to the housing of the electric drive unit.

In some examples, the panel is configured to be attached to the housing using at least one fastener, and wherein the panel is configured to allow, when attached to the housing, an electrically conductive path from the electrically conductive layer to the housing via the at least one fastener.

This provides the advantage that an existing attachment can be used to create a faraday cage is created.

According to a further aspect of the invention there is provided a vehicle component comprising: an electric drive unit; and a panel as described herein.

According to a further aspect of the invention there is provided a vehicle comprising a panel as described herein and/or a vehicle component as described herein.

According to an aspect of the invention there is provided a vehicle component panel comprising: a first and second layer; the first layer comprising an electrically conductive layer configured to prevent, in use, at least a portion of electromagnetic radiation produced by the vehicle component from passing through the electrically conductive layer; and the second layer comprising an electrically non-conductive layer configured to support the conductive layer.

In some examples, the vehicle component comprises at least one electric drive unit, and/or at least one battery, and/or at least one high voltage DC to DC (HVDCDC) converter, and/or at least one inverter.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination that falls within the scope of the appended claims. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination that falls within the scope of the appended claims, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG. 1 illustrates an example of a vehicle; FIG. 2 illustrates an example of an electric drive unit panel; FIG. 3 illustrates an example scenario; FIG. 4 illustrates an example scenario; FIG. 5 illustrates an example electrically conductive layer; FIG. 6 illustrates an example vehicle component; and FIG. 7 illustrates an example of an electric drive unit panel.

DETAILED DESCRIPTION

FIG. 1 illustrates an example of a vehicle in which embodiments of the invention can be implemented. In some, but not necessarily all examples, the vehicle is a passenger vehicle, also referred to as a passenger car or as an automobile. In other examples, embodiments of the invention can be implemented for other applications, such as commercial vehicles.

FIG. 1 is a front perspective view and illustrates a longitudinal x-axis between the front and rear of the vehicle representing a centreline, an orthogonal lateral y-axis between left and right lateral sides of the vehicle, and a vertical z-axis. A forward/fore direction typically faced by a driver's seat is in the negative x-direction; rearward/aft is +x. A rightward direction as seen from the driver's seat is in the positive y-direction; leftward is -y. These are a first lateral direction and a second lateral direction.

The vehicle 10 comprises an electric drive unit 24 (EDU) and an associated electric drive unit panel 14. In the example of FIG. 1 the EDU 24 and the EDU panel 14 are comprised in a vehicle component 12.

Accordingly, FIG. 1 illustrates a vehicle component 12 comprising: an electric drive unit 24 and a panel 14 as described herein.

Accordingly, FIG. 1 illustrates a vehicle 1 comprising a panel 14 as described herein and/or a vehicle component 12 as described herein.

In examples, an EDU 24 comprises an electric motor, a gearbox, transmission, and an inverter. In some examples, the electric motor can be considered an electric machine.

The electric drive unit panel 14 can be considered to be associated with the EDU 24 because the electric drive unit panel 14 is configured to, at least partially, cover, and/or shield, and/or protect, and/or house the EDU 24.

The EDU panel 14 can comprise any suitable panel 14. For example, the EDU panel 14 can comprise any suitable panel configured to form at least part of a housing 36 for the EDU 24. See, for example, FIG. 3.

In examples, the vehicle component 12 can comprise any suitable vehicle component 12. For example, the vehicle component 12 can comprise any suitable vehicle component comprising an EDU 24.

FIG. 2 schematically illustrates an example of an EDU panel 14.

One or more features referred to in the discussion of FIG. 2 can be found in the other figures. Furthermore, during the discussion of FIG. 2, reference will be made to one or more of the other figures by way of example.

In the example of FIG. 2, the EDU panel 14 is shown in section and comprises: a first and second layer 16, 18; the first layer 16 comprising an electrically conductive layer 20 configured to prevent, in use, at least a portion of electromagnetic radiation 22 produced by the EDU 24 from passing through the electrically conductive layer 20; and the second layer 18 comprising an electrically non-conductive layer 26 configured to support the electrically conductive layer 20.

In examples, the EDU panel 14 can be considered an EDU cover, and/or an EDU covering, and/or an EDU housing portion, and/or an EDU shield, and/or an end cover and so on.

In some examples, the panel 14 can be configured for use with any suitable vehicle component or components. Accordingly, in examples, the panel 14 can be considered a vehicle component cover, and/or a vehicle component covering, and/or a vehicle component housing portion, and/or a vehicle component shield and so on.

For example, the panel 14 can be configured for use with any suitable equipment in a vehicle, such as any suitable high voltage equipment in a vehicle.

For example, the panel 14 can be configured for use with and/or in relation to at least one battery, at least one high voltage DC to DC (HVDCDC) converter, at least one inverter and so on.

In examples, the panel 14 can be considered a battery cover, and/or a battery covering, and/or a battery housing portion, and/or a battery shield, and/or an end cover and so on.

In examples, the panel 14 can be considered an HVDCDC converter cover, and/or an HVDCDC covering, and/or an HVDCDC housing portion, and/or an HVDCDC shield, and/or an end cover and so on.

In examples, the panel 14 can be considered an inverter cover, and/or an inverter covering, and/or an inverter housing portion, and/or an inverter shield, and/or an end cover and so on.

The EDU panel 14 can have any suitable shape, size and/or form. For example, the EDU panel 14 can have any suitable shape, size and/or form to form any portion of a housing of an EDU 24. That is, in examples, any portion of a housing 36 of an EDU 24 can be considered an EDU panel 14.

In some examples, the EDU panel 14 can comprise any non-structural component of the EDU housing 36.

A non-structural component can be considered a component that does not contribute to maintain required stiffness of an entity, for example an EDU housing 36.

The electrically conductive layer 20 can comprise any suitable electrically conductive layer 20. For example, the electrically conductive layer 20 can comprise any suitable electrically conductive layer 20 configured to prevent, in use, at least a portion of electromagnetic radiation 22 produced by the EDU 24 from passing through the electrically conductive layer 20.

In examples, the electrically conductive layer 20 can comprise any suitable electrically conductive layer 20 configured to prevent, in use, electromagnetic radiation 22 produced by the EDU 24 from passing through the electrically conductive layer 20.

In examples, the electrically conductive layer 20 can comprise any suitable electrically conductive layer 20 configured to reduce an amount of electromagnetic radiation 22 passing through the EDU panel 14 to an acceptable amount with regard to safe operating limits.

For example, the electrically conductive layer 20 can comprise any suitable electrically conductive layer 20 configured to form at least part of a Faraday cage around the EDU 24.

For example, the electrically conductive layer 20 can comprise any suitable electrically conductive layer 20 configured to close at least an end 38 of the housing 36 to complete a Faraday cage around the EDU 24, when the panel 14 is attached to the housing 36 of the EDU 24.

In examples, the electrically conductive layer 20 can have any suitable shape, size and/or form. For example, the electrically conductive layer 20 can have a similar or the same shape and size as the electrically non-conductive layer 26.

The electrically conductive layer 20 can comprise any suitable material or materials. For example, the electrically conductive layer 20 can comprise any suitable electrically conductive material or materials.

For example, the electrically conductive layer 20 can comprise at least one of copper mesh, steel mesh, aluminium mesh, copper foil, steel foil, aluminium foil and so on.

In some examples, the electrically conductive layer 20 may comprise carbon fabric with connection points for electrical connection to adjacent components.

In some examples, the maximum resistivity of the material or materials of the electrically conductive layer 20 is 10x10^-8 Ohm/m.

In examples, the electrically conductive layer 20 of the panel 14 is configured to form at least part of a Faraday cage around the EDU 24. For example, the electrically conductive layer 20 can be configured to form at least part of an EDU housing 36 that forms a Faraday cage around the EDU 24.

A Faraday cage may be considered a Faraday shield.

In examples, the electrically conductive layer comprises a plurality of holes 30 and wherein the largest dimension 32 of the holes 30 is less than a value determined in dependence on the frequency or frequencies of electromagnetic radiation 22 at least a portion of which is to be prevented, in use, from passing through the electrically conductive layer 20.

For example, the hole size of the holes 30 in the electrically conductive layer 20 can depend on the electromagnetic frequency or frequencies that is being protected for.

The plurality of holes 30 can have any suitable shape, size and/or form. In examples, different ones of the plurality of holes 30 can have different shapes, sizes and/or forms.

In some examples, the plurality of holes 30 are similar and/or the same to within manufacturing tolerances.

The plurality of holes 30 can have any suitable shape, size and/or form to prevent, in use, at least a portion of electromagnetic radiation 22 produced by the EDU 24 from passing through the electrically conductive layer 20.

By way of example, reference is made to the example of FIG. 5. FIG. 5 schematically illustrates an example of an electrically conductive layer 14.

In the example of FIG. 5, the electrically conductive layer 14 comprises a plurality of holes 30.

In the illustrated example, the electrically conductive layer 20 comprises a wire mesh.

Accordingly, in examples, the electrically conductive layer 20 comprises a wire mesh.

In the example of FIG. 5, the largest dimension 32 of one of the holes 30 is indicated by a double-headed arrow.

In the example of FIG. 5, as the electrically conductive layer 20 has the form of a wire mesh, the largest dimension 32 is diagonally across the hole 30.

Returning to the discussion of FIG. 2, in examples, the largest dimension of the holes 30 is in the range 2mm to 16mm.

In some examples, the largest dimension 32 of the holes 30 is 2.5mm or 15mm.

In some examples, the largest dimension 32 of the holes is one twentieth of the electromagnetic radiation wavelength 22 at least a portion of which is to be prevented, in use, from passing through the electrically conductive layer 20. For example, to substantially prevent electromagnetic radiation with a frequency of 5 GHz, the hole size would have to be less than 3 mm.

The electrically non-conductive layer 26 can comprise any suitable electrically non-conductive layer 26.

For example, the electrically non-conductive layer 26 can comprise any suitable electrically non-conductive layer 26 configured to support the electrically conductive layer 20 and that is less dense than the material of the electrically conductive layer 20.

The electrically non-conductive layer 26 can have any suitable shape, size and/or form. For example, the electrically non-conductive layer 26 can have any suitable shape, size and/or form to support the electrically conductive layer 20.

In examples, the electrically non-conductive layer 26 can have any suitable shape, size and/or form to support the electrically conductive layer 20 to allow the electrically conductive layer 20 to form at least part of a Faraday cage around the EDU 24.

In examples, the electrically non-conductive layer 26 can be configured to support the electrically conductive layer 20 so that the electrically conductive layer 20 is configured to prevent, in use, at least a portion of electromagnetic radiation 22 produced by the EDU 24 from passing through the electrically conductive layer 20.

In examples, the electrically non-conductive layer 26 can comprise any suitable material or materials. For example, the electrically non-conductive layer 26 can comprise any suitable material or materials configured to support the electrically conductive layer 20 and that is less dense than the material or materials used in the electrically conductive layer 20.

For example, the electrically non-conductive layer 26 can comprise any suitable plastics and/or composite material(s) and so on.

In some examples, the minimum resistivity of the material or materials of the electrically non-conductive layer is lx10^16 Ohm/m.

In examples, the electrically non-conductive layer 26 can be considered to support the electrically conductive layer 20 because the electrically conductive layer 20 is located in and/or on the electrically non-conductive layer 26.

In examples, the electrically non-conductive layer 26 can be considered to support the electrically conductive layer 20 because the electrically non-conductive layer 26 provides stiffness, and/or strength and/or rigidity to the electrically conductive layer 20.

In some examples, the electrically conductive layer 20 is embedded within the electrically non-conductive layer 26.

In some examples, the electrically conductive layer 20 is integrated with the electrically nonconductive layer 26.

In examples, the electrically conductive layer 20 can be considered to be embedded within the electrically non-conductive layer 26 if the material(s) of the electrically non-conductive layer 26 surrounds the electrically conductive layer 20, apart from at connection points. The connection points allowing an electrically conductive path between the electrically conductive layer and adjacent components, directly or through fixings, further extending the Faraday cage around the EDU 24. The connection point may comprise a metallic bush around a fixing hole with electrical connection to the conductive layer, this bush may further provide a compression limiting function. One or more connection points may be threaded holes for fitting fill and/or drain plugs to allow the lubricant to be serviced and an electrical connection to these plugs prevents a hole being formed in the Faraday cage.

In some examples, the first and second layers 16, 18 are coextensive in any, or all, directions except thickness.

That is, in examples, the first and second layers 16, 18 have the same shape and/or size to within manufacturing tolerances.

In some examples, the panel 14 is configured to be attached to a housing 36 of the EDU 24 and wherein the panel 14 is configured to allow, when attached to the housing 36, an electrically conductive path 34 from the electrically conductive layer 20 to the housing 36.

The panel 14 can be configured in any suitable way to allow an electrically conductive path 34 from the electrically conductive layer 20 to the housing 36 when the panel 14 is attached to the housing 36.

For example, the housing and/or panel 14 can comprise a plurality of electrically conductive connection points to provide an electrically conductive path 34 from the electrically conductive layer 20 to the housing 36.

By way of example, reference is made to the example of FIG. 3.

The example of FIG. 3 schematically illustrates an EDU housing 36 and panel 14 in cross-section. In the example of FIG. 3, portions of the housing 36 to which the EDU panel 14 is attached are shown.

In the example of FIG. 3, the panel 14 comprises a first layer 16 comprising an electrically conductive layer 20 in the form of a wire mesh comprising a plurality of holes 30.

In the example of FIG. 3, the panel 14 comprises a second layer 18 comprising an electrically non-conductive layer 26 which, in the illustrated example, is formed from a plastics material.

This non-conductive layer may provide structural strength and/or stiffness and/or may provide closure to contain lubricant and exclude contaminants. The non-conductive layer may provide location for internal EDU components and/or features to guide lubricant flow. The conductive layer may be provided with features, such as fins extending internally and/or externally, to provide heat transfer from the lubricant to the external airflow around the EDU. Other common features such as fill/level plug holes are also envisaged. Further features such as clips or bosses for supporting pipes, electrical wiring, or other components may be incorporated into the cover. The non-conductive layer may comprise, in whole or in part, a foam or felt material for attenuation of radiated audible noise. Webs may be provided on the cover to increase the stiffness of areas of the structure and/or to provide sealing between different areas of the EDU.

In the illustrated example, the electrically conductive layer 20 of the panel 14 is configured to close at least an end 38 of the housing 36 to complete a Faraday cage around the EDU 24, when the panel 14 is attached to the housing 36 of the EDU 24.

Accordingly, in examples, the electrically conductive layer 20 of the panel 14 is configured to close at least an end 38 of the housing 36 to complete a Faraday cage around the EDU 24, when the panel 14 is attached to the housing 36 of the EDU 24.

Also illustrated in the example of FIG. 3 is the EDU 24 and electromagnetic radiation 22 generated by the EDU 24 that is incident upon and bounces off the EDU panel 14.

In some examples, the panel 14 is configured to be attached to the housing 26 using at least one fastener 40, and wherein the panel 14 is configured to allow, when attached to the housing 36, an electrically conductive path 34 from the electrically conductive layer 20 to the housing 36 via the at least one fastener 40.

In examples, any suitable fastener or fasteners 40 of any suitable type or types can be used to attach the panel 14 to the housing 36. For example, any suitable fastener or fasteners 40 configured to attach the panel 14 to the housing 36 and to provide an electrically conductive path 34 from the electrically conductive layer 20 to the housing 36 can be used.

For example, the at least one fastener 40 can comprise at least one bolt, at least one rivet, at least one screw, at least one self threading screw, at least one self tapping screw, and/or at least one dowel and so on.

Referring again to the example of FIG. 3, in the illustrated example the panel 14 is attached to the housing 36 by a plurality of fasteners 40 in the form of bolts.

In the example of FIG. 3, an electrically conductive path 34 is provided from the electrically conductive layer 20 to the housing 36 via the bolts 40.

By way of example, reference is made to the example of FIG. 4.

FIG. 4 shows a larger view of the area indicated by the circle in the example of FIG. 3.

In the example of FIG. 4, it can be seen that an electrically conductive path 34 is provided from the electrically conductive layer 20 to the housing 36 via the fastener 40.

Also illustrated in the example of FIG. 4 is a sealing insulating layer 42 between the panel 14 and the housing 36. Any suitable sealing insulating layer 42 can be used. For example, reinforced thermoplastic composites (RTC) can be used.

FIG. 6 schematically illustrates an example of a vehicle component 12.

In the example of FIG. 6, the vehicle component 12 comprises an EDU 24 and EDU panel 14 that is described herein.

Accordingly, FIG. 6 illustrates an example of a vehicle component 12 comprising: an EDU 24 and a panel 14 as described herein.

In examples, the vehicle component 12 can comprise any suitable vehicle component.

FIG. 7 illustrates an example of an EDU panel 14.

In the example of FIG. 7 the EDU panel 14 comprises a first layer 16 and a second layer 18 as described herein.

In the example of FIG. 7, also referring to FIG. 3, the EDU panel 14 is configured to be attached to a housing 36 of the EDU and is configured, in use, to close an end 38 of the housing 26 to complete a Faraday cage around the EDU 24.

In the illustrated example, the EDU panel 14 comprises a plurality of fastening and/or attachment points 44 configured to allow the EDU panel 14 to be attached to the housing 36 using a plurality of fasteners 40.

Examples of the disclosure are advantageous and/or provide one or more technical benefits. 10 For example, examples of the disclosure provide for sheilding of electromagnetic radiation 22 from an EDU 24 to be maintained while providing a cost and/or weight benefit. The use of lower density plastics or composite materials may provide a beneficial weight reduction over the use of a conductive metallic cover. Material cost may be lower, and the plastics/composite cover may be formed without the need for further machining, reducing the processing cost of the part.

It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed.

Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

CLAIMS1. An electric drive unit panel comprising: a first and second layer; the first layer comprising an electrically conductive layer configured to prevent, in use, at least a portion of electromagnetic radiation produced by the electric drive unit from passing through the electrically conductive layer; and the second layer comprising an electrically non-conductive layer configured to support the electrically conductive layer.
2. A panel as claimed in claim 1, wherein the electrically conductive layer of the panel is configured to form at least part of a Faraday cage around the electric drive unit.
3. A panel as claimed in claim 1 or 2, wherein the first and second layers are coextensive.
4. A panel as claimed in any preceding claim, wherein the electrically conductive layer is embedded within the electrically non-conductive layer.
5. A panel as claimed in any preceding claim, wherein the electrically conductive layer comprises a plurality of holes and wherein the largest dimension of the holes is less than a value determined in dependence on the frequency or frequencies of electromagnetic radiation at least a portion of which is to be prevented, in use, from passing through the electrically conductive layer.
6. A panel as claimed in claim 5, wherein the largest dimension of the holes is in the range 2mm to 16mm.
7. A panel as claimed in claim 5 or 6, wherein the largest dimension of the holes is 2.5mm or 15mm.
8. A panel as claimed in claim 5, 6 or 7, wherein the electrically conductive layer comprises a wire mesh.
9. A panel as claimed in any preceding claim, wherein the panel is configured to be attached to a housing of the electric drive unit and wherein the panel is configured to allow, when attached to the housing, an electrically conductive path from the electrically conductive layer to the housing.
10. A panel as claimed in claim 9, wherein the electrically conductive layer of the panel is configured to close at least an end of the housing to complete a Faraday cage around the electric drive unit, when the panel is attached to the housing of the electric drive unit.
11. A panel as claimed in claim 9 or 10, wherein the panel is configured to be attached to the housing using at least one fastener, and wherein the panel is configured to allow, when attached to the housing, an electrically conductive path from the electrically conductive layer to the housing via the at least one fastener.
12. A vehicle component comprising: an electric drive unit; and a panel as claimed in at least one of claims 1 to 11.
13. A vehicle comprising a panel as claimed in at least one of claims 1 to 11 and/or a vehicle component as claimed in claim 12.
14. A panel for an electric drive unit, comprising: an electrically conductive layer configured to prevent, in use, at least a portion of electromagnetic radiation produced by the electric drive unit from passing through the electrically conductive layer; and an electrically non-conductive layer configured to support the electrically conductive layer
15. An electric drive unit comprising a housing mounting an electrical component which, in use, emits electromagnetic radiation, wherein the housing is adapted to shield the electrical component and prevent electromagnetic radiation from exiting the drive unit, wherein the housing has an opening that is closed by a panel as claimed in claim 14, the electrically conductive layer thereof being in electrical contact with the housing.