Electric drive unit assembly

Abstract

An electric vehicle drive assembly 12, comprising: a housing 16 defining a cavity 18 to house the electric drive unit motor 14; and a breather spigot 20, extending through the housing 16, having a bor

Description

TECHNICAL FIELD The present disclosure relates to an electric drive unit assembly. Aspects of the invention relate to an electric drive unit assembly, to a powertrain assembly, and to a vehicle. BACKGROUND It is known for various components of a vehicle to be provided with a breather spigot. A breather spigot serves to avoid a build up of pressure in the component by permitting the internal pressure to equalize with the external environment to which it is fluidly connected to by the breather spigot. A known challenge associated with the use of breather spigots is the undesired leakage of fluids such as lubricants from the component through the breather spigot. 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 assembly, a powertrain assembly, and a vehicle. According to an aspect of the present invention there is provided an electric drive unit assembly, comprising a first housing defining a first cavity for housing at least part of an electric drive unit, and a breather spigot that extends through the first housing, the breather spigot having a bore that is in fluid communication with the first cavity. According to an aspect of the present invention there is provided an electric drive unit assembly, comprising an electric drive unit, a first housing defining a first cavity that houses at least part of the electric drive unit, and a breather spigot that extends through the first housing, the breather spigot having a bore that is in fluid communication with the first cavity. Positioning of the breather spigot through the first housing may have a lower associated possibility of fluids (such as lubricants and the like) inadvertently exiting through the breather spigot relative to an arrangement in which the breather spigot is positioned elsewhere. In certain embodiments, the breather spigot extends into the first cavity. Such an arrangement may further inhibit the passage of fluid out of the first cavity through the bore (such as by capillary action). In certain embodiments, an end portion of the breather spigot that extends into first cavity is circumferentially discontinuous. Such an arrangement may permit the breather spigot to extend into the first cavity whilst being arranged with a desired minimum distance between it and the electric drive unit. In certain embodiments, a first portion of the first cavity surrounds a stator end winding of the electric drive unit, and wherein the breather spigot extends into the first portion. The first portion may contain a lower volume of fluid (if any at all) relative to other portions of the first cavity. In certain embodiments, there is a minimum distance of at least 5 mm between the breather spigot and the stator end winding. Such an arrangement reduces the possibility of fluids exiting the first cavity through the breather spigot. In certain embodiments, the bore has a diameter between 3 mm and 5 mm. Such a diameter permits the breather spigot to perform its desired function whilst maintaining a low possibility of fluid exiting the first cavity through the breather spigot. In certain embodiments, the electric drive unit assembly comprises an o-ring disposed on an external surface of the breather spigot sealing the breather spigot to the first housing. Additionally or alternatively, the electric drive unit may comprise a sealant that seals the breather spigot to the first housing. The o-ring and / or sealant seals the breather spigot to the first housing thereby reducing the possibility of fluid exiting the first cavity around the breather spigot. According to another aspect of the present invention, there is provided a powertrain assembly comprising an electric drive unit assembly as described above, a transmission drivably coupled to the electric drive unit, and a second housing defining a second cavity that that houses at least part of the transmission. It is likely that many fluids will be present within the second housing, on or around the transmission. Positioning of the breather spigot through the first housing therefore carries a lower risk of fluid exiting through the breather spigot. In certain embodiments, the first cavity does not house any part of the transmission. In certain embodiments, the second cavity does not house any part of the electric drive unit. In certain embodiments, the powertrain assembly may comprise one or more spray outlets in the second cavity for spraying fluids on or around the transmission. Positioning of the breather spigot through the first housing may therefore lower the possibility of the sprayed fluids exiting the powertrain assembly. According to another aspect of the present invention, there is provided a vehicle comprising an electric drive unit assembly as described above. According to another aspect of the present invention, there is provided a vehicle comprising a powertrain assembly as described above. 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 is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, 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 shows a cross-sectional view of a powertrain assembly in accordance with an embodiment of the present invention; FIG. 2 shows a perspective view of a breather spigot in accordance with an embodiment of the present invention; and FIG. 3 shows a vehicle in accordance with an embodiment of the present invention. DETAILED DESCRIPTION FIG. 1 shows a cross-sectional view of a powertrain assembly 10 in accordance with an embodiment of the present invention. The powertrain assembly 10 comprises an electric drive unit assembly 12 having a first housing 16 that defines a first cavity 18 that houses an electric drive unit 14. The powertrain assembly 10 additionally comprises a second housing 34 defining a second cavity 36 that houses a transmission 32. The electric drive unit 14 is arranged to provide drive to the transmission 32. In the non-limiting embodiment shown in the FIG. 1, the first housing 16 and second housing 34 are adjacent to one another and share a common wall. In other embodiments, other arrangements may be realised. Also in the non-limiting embodiment shown in FIG. 1, the first housing 16 does not house any part of the transmission 32 and the second housing 34 does not house any part of the electric drive unit 14. A breather spigot 20 extends through the first housing 16. In the non-limiting depicted embodiment, an o-ring 30 seals the breather spigot 20 to the first housing 16. In other embodiments, other sealing arrangements may be provided, including but not limited to sealants, and friction fits. The breather spigot 20 has a bore 22 that is in fluid communication with the first cavity 18. Therefore, the breather spigot 20 puts the first cavity 18 in fluid communication with an environment external of the first housing 16. Consequently, the breather spigot 20 may allow pressure within the first cavity 18 to equalise with pressure outside of the first cavity 18. In certain embodiments, the breather spigot 20 is located in the topmost position of the cavity in which the electric drive unit 14 is disposed (i.e. the first cavity 18 in the non-limiting depicted embodiment). The first cavity 18 may contain a lower volume of fluids (or substantially none at all) relative to the second cavity 36. Consequently, positioning of the breather spigot 20 through the first housing 16 may have a lower associated possibility of fluids (such as lubricants and the like) inadvertently exiting through the breather spigot 20 relative to an arrangement in which the breather spigot 20 extends through the second cavity 36. The above-described embodiments may be particularly beneficial in arrangements in which one or more spray outlets 44 are provided in the second cavity 36 for spraying fluids (such as lubricants) on or around the transmission 32. This may be in contrast to other arrangements whereby fluids are not sprayed but are allowed to splash onto or around the transmission 32. The former arrangement may present a higher possibility of fluids exiting powertrain assembly 10 if the breather spigot 20 is in fluid communication with the second cavity. In the specific non-limiting embodiment shown in FIG. 1, an end portion 24 of the breather spigot 20 terminates in or adjacent to a first portion 26 of the first cavity 18, where the first portion 26 surrounds a stator end winding 28 of the electric drive unit 14. The stator end winding 28 and the surrounding volume of the first cavity 18 have notably few (if any) associated fluids present during use. Therefore, the depicted embodiment in which the breather spigot 20 terminates in or adjacent to the first portion 26 results in an arrangement in which the breather spigot 20 is in direct fluid communication with a portion of the first cavity 18 that contains a particularly low volume of fluids (if any) during use. Placement of the breather spigot 20 in this manner may have a lower associated possibility of fluids inadvertently exiting through the breather spigot 20 relative to alternative placements. Due to this advantageous placement, the bore 22 may, in some embodiments, be a simple straight throughbore that does not include any baffles or other features creating a tortuous path, and still maintain an acceptably low possibility of fluid exiting therethrough. In the non-limiting embodiment shown in FIG. 1, the breather spigot 20 extends into the first cavity 18. By doing so, any fluids travelling along inner walls of the first cavity 18 must traverse an outer surface of the breather spigot 20 before being able to enter the bore 22 and exit therethrough. Therefore, extension of the breather spigot 20 into the first cavity 18 makes this process less likely and therefore serves to lower the possibility of fluids exiting the first cavity 18 through the breather spigot 20. In particular, the possibility of fluids moving through the bore 22 by capillary action is lowered. In certain embodiments, the breather spigot 20 extends into the first cavity 18 by at least 3mm. In certain embodiments, the breather spigot 20 may extend into the first cavity 18 by between 3 mm and 5 mm. Such extensions may be particularly effective at reducing the possibility of fluids exiting the first cavity 18 through the breather spigot 20. In certain embodiments, maintaining a minimum distance between the breather spigot 20 and the stator end winding 28 may be beneficial, as such minimum distance may serve to reduce the possibility of fluids exiting the first cavity 18 through the breather spigot 20. In certain embodiments, the minimum distance may be at least 5 mm. In the non-limiting depicted embodiment shown in FIG. 1 and FIG. 2 , the end portion 24 of the breather spigot 20 is circumferentially discontinuous. That is, a wall of the end portion 24 does not complete a full circle about the bore 22. In the illustrated embodiment, the wall extends along an arc of 180° such that in cross-section, the wall 4 has a u-shaped profile. In other embodiments, the wall may extend along an arc having an angular extent other than 180°. In certain embodiments, some or all of the end portion 24 may be circumferentially discontinuous (while in other embodiments, the end portion 24 may be entirely circumferentially continuous). The circumferentially discontinuous end portion 24 defines a “cut out”, and this cut out may allow the breather spigot 20 to extend into the first cavity 18 by a desired amount whilst maintaining a minimum distance between the breather spigot 20 and the stator end winding 28. The bore 22 may have a diameter that permits sufficient equalisation of pressure in the first cavity 18 with an environment outside of the first cavity 18. In certain embodiments, the bore 22 may have a diameter between 2 mm and 6 mm, and optionally between 3 mm and 5 mm. Such diameters may allow the breather spigot 20 to perform its desired function adequately whilst not being so large as to unnecessarily increase the possibility of fluids exiting the first cavity 18 through the breather spigot 20. FIG. 2 shows a more detailed perspective view of the breather spigot 20 in accordance with an embodiment of the present invention. As shown in FIG. 2 the breather spigot 20 is substantially tubular, but for the circumferentially discontinuous end portion 24. A mounting bracket 40 is provided in the non-limiting embodiment shown in FIG. 2. The mounting bracket 40 may serve to mount the breather spigot 20 to or relative to the first housing 16. The mounting bracket 40 has a mounting aperture 42 for receiving a fastener for mounting the breather spigot 20 to or relative to the first housing 16. In the non-limiting embodiment shown in FIG. 2, the mounting bracket 40 is rotationally fixed and non-symmetrical relative to the breather spigot 20. The mounting bracket 40 may be mountable to a part of the first housing 16 (or another component proximate to the first housing 16) so that the mounting bracket 40 mates or aligns with a feature of the first housing 16 (or proximate component) and / or the mounting aperture 42 aligns with a mounting feature (such as a threaded bore) of the first housing 16 (or proximate component). In this manner, the breather spigot 20 may only be successfully mounted to or relative to the first housing 16 in a particular orientation. In this particular orientation, the cut out may be orientated in a desired manner within the first cavity 18 relative to the stator end winding 28. Consequently, the configuration of the mounting bracket 40 may ensure that the breather spigot 20 is assembled in the electric drive unit assembly 12 in the desired orientation. FIG. 3 shows a vehicle 38 in accordance with an embodiment of the present invention. The vehicle 38 may comprise the above-described electric drive unit 14, or the vehicle 38 may comprise the above-described powertrain assembly 10. 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.

Claims

1. An electric drive unit assembly, comprising:an electric drive unit;a first housing defining a first cavity that houses at least part of the electric drive unit; anda breather spigot that extends through the first housing, the breather spigot having a bore that is in fluid communication with the first cavity.

2. An electric drive unit assembly according to claim 1, wherein the breather spigot extends into the first cavity.

3. An electric drive unit assembly according to claim 2, wherein the breather spigot extends into the first cavity by at least 2 mm, and optionally between 2 mm and 4 mm.

4. An electric drive unit assembly according to claim 2 or 3, wherein an end portion of the breather spigot that extends into first cavity is circumferentially discontinuous.

5. An electric drive unit assembly according to any of claims 2 to 4, wherein a first portion of the first cavity surrounds a stator end winding of the electric drive unit, and wherein the breather spigot extends into the first portion.

6. An electric drive unit assembly according to claim 5, wherein there is a minimum distance of at least 5 mm between the breather spigot and the stator end winding.

7. An electric drive unit assembly according to any preceding claim, wherein the bore has a diameter between 3 mm and 5 mm.

8. An electric drive unit assembly according to any preceding claim, comprising an o-ring disposed on an external surface of the breather spigot sealing the breather spigot to the first housing.

9. An electric drive unit assembly according to any preceding claim, comprising a sealant that seals the breather spigot to the first housing.

10. A powertrain assembly comprising:an electric drive unit assembly according to any preceding claim;a transmission drivably coupled to the electric drive unit; anda second housing defining a second cavity that that houses at least part of the transmission.

11. A powertrain assembly according to claim 10, wherein the first cavity does not house any part of the transmission.

12. A powertrain assembly according to claim 10 or 11, wherein the second cavity does not house any part of the electric drive unit.

13. A powertrain assembly according to any one of claims 10 to 12, comprising one or more spray outlets in the second cavity for spraying fluids on or around the transmission.

14. A vehicle comprising an electric drive unit assembly according to any of claims 1 to 9.

15. A vehicle comprising a powertrain assembly according to any of claims 10 to 12.Application No: GB2318247.0Examiner:James GulliverClaims searched: 1-15Date of search: 31 May 2024Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance X 1-15 US 2023 / 0058881 Al (ASAKURA et al.) - See especially Figures 1 and 3, and paragraphs [0017], [0025], and [0035] X 1-4 and 7- 15 CN 114157074 A (SHUFLER TECH STOCK TWO IN ONE COMPANY) - See especially Figures 1-2, and description under “background technique” X 1-4 and 7- 15 US 2011 / 0221294 Al (SATO et al.) - See especially Figures 1 and 3, and paragraphs [0024-25] X 1, and 3- 15 JP 2001260675 A (JATCO TRANSTECHNOLOGY LTD) - See especially Figures 2-3, and paragraphs [0037-38] X 1-15 US 2009 / 0206709 Al (KAKUDA et al.) - See especially Figure 1 and 8, and paragraph [0031] A - WO 2007 / 058206 Al (NITTO DENKO CORP) - See especially Fig. 5 with segments 161, 162 separated by gaps A - US 2007 / 0295158 Al (ADLEMAN et al.) - See especially Fig. 4 with legs 84 A - US 2020 / 0278021 Al (SOEHNGE et al.) - See especially Fig. 3 with slots 38 and stop sections 37 A - DE 102015002320 B4 (GKN AUTOMOTIVE LTD) - See especially Figs. 3 and 4 with spigot 'chimney' 7, having a space 14 from the opposite facing wall, with ridges and troughs 15, 15.1Categories:v Au Document indicating lack of novelty or inventive step A Document indicating technological background and or state of the art. Y Document indicating lack of inventive step if p Document published on or after the declared priority date but combined with one or more other documents of same category. before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority dateearlier than, the filing date of this application.Field of Search:International Classification:Subclass Subgroup Valid From H02K 0009 / 02 01 / 01 / 2006 B60K 0001 / 00 01 / 01 / 2006 H02K 0005 / 20 01 / 01 / 2006Intellectual Property Office is an operating name of the Patent Ofncewww.gov.uk / ipo

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