Bearing retention sleeve

Abstract

Aspects of the present invention relate to a bearing retention sleeve (2, 20, 20', 21, 2") for axially constraining a bearing (5, 50) on a shaft (4, 40). The bearing retention sleeve comprises a bore defined by a radially inner surface, the bore for receiving the shaft; a bearing abutment face (22, 220, 220') for axially abutting a part of the bearing which is located on the shaft; a circlip groove (21, 210, 210') extending radially outwardly from the radially inner surface, the circlip groove having a bevelled circlip abutment face (23, 230, 230') on a side of the circlip groove nearest to the bearing abutment face. The bevelled circlip abutment face is bevelled in a direction away from the radially inner surface and away from the bearing abutment face.

Description

[0001] BEARING RETENTION SLEEVE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a bearing retention sleeve. Aspects of the invention relate to a bearing retention sleeve, to a bevelled circlip, to a bearing retention system, to an axial tool, to a drivetrain and to a vehicle.

[0004] BACKGROUND

[0005] It is known to use circlips or other retention means to retain bearings on shafts and in housings. Circlips and other retention rings are usually received in, and protrude from, grooves such that an axial face of the bearing abuts the protruding part of the circlip, to axially retain the bearing.

[0006] When circlips are located on shafts, a centrifugal force caused by rotation of the shafts at high speed may cause the circlip to expand radially, and so the circlip may become loose in, or even come out of, the groove.

[0007] It is an aim of the present invention to address one or more of the disadvantages associated with the prior art.

[0008] SUMMARY OF THE INVENTION

[0009] Aspects and embodiments of the invention provide a bearing retention sleeve, a bearing retention system and a bevelled circlip, as claimed in the appended claims.

[0010] According to an aspect of the present invention there is provided a bearing retention sleeve with an internal circlip groove having a bevelled circlip abutment face. The bearing retention sleeve may comprise a bore defined by a radially inner surface, the bore for receiving a shaft. The bearing retention sleeve may comprise a bearing abutment face for axially abutting a part of a bearing which is located on the shaft. The circlip groove may extend radially outwardly from the radially inner surface. The circlip groove may have the bevelled circlip abutment face on a side of the circlip groove nearest to the bearing abutment face. The bevelled circlip abutment face may be bevelled in a direction away from the radially inner surface and away from the bearing abutment face.

[0011] Another aspect of the invention provides a bearing retention sleeve for axially constraining a bearing on a shaft, the bearing retention sleeve comprising: a bore defined by a radially inner surface, the bore for receiving a shaft; a bearing abutment face for axially abutting a part of a bearing which is located on the shaft; a circlip groove extending radially outwardly from the radially inner surface, the circlip groove having a bevelled circlip abutment face on a side of the circlip groove nearest to the bearing abutment face; wherein the bevelled circlip abutment face is bevelled in a direction away from the radially inner surface and away from the bearing abutment face. Another aspect of the invention provides a bearing retention system comprising: a bearing retention sleeve; a bevelled circlip; and a shaft received or receivable into a bore of the bearing retention sleeve, the bore defined by a radially inner surface of the bearing retention sleeve, the bearing retention sleeve for axially constraining a bearing on the shaft, the bearing retention sleeve comprising: a bearing abutment face for axially abutting a part of a bearing which is located on the shaft; and a circlip groove extending radially outwardly from the radially inner surface, the circlip groove having a bevelled circlip abutment face on a side of the circlip groove nearest to the bearing abutment face.

[0012] The bevelled circlip abutment face is bevelled in a direction away from the radially inner surface and away from the bearing abutment face, and the shaft comprises a circlip groove for corresponding with the circlip groove of the bearing retention sleeve, the bevelled circlip received or receivable in the circlip groove of the shaft and in the circlip groove of the bearing retention sleeve, to retain the bearing retention sleeve on the shaft.

[0013] The expression ‘bevelled’ may be otherwise referred to as a chamfer or an angled face, for example an angled planar face. The term ‘circlip’ may relate to suitability for use with a circlip, or another retention ring such as a snap ring.

[0014] Advantageously, the bearing retention sleeve may be axially constrained on the shaft with a bevelled circlip, with a bevel of the circlip abutting the bevelled circlip abutment face of the bearing retention sleeve. This may mean that, when the shaft is rotated and a centrifugal force causes the circlip to expand, the abutment of the bevelled faces reinforces the abutting contact between the bearing abutment face of the sleeve and the bearing. The may overcome the problem of external circlips becoming loose due to centrifugal forces. It will be appreciated that by centrifugal force it is meant an apparent force which acts to expand a rotating body, directed radially away from the centre of rotation.

[0015] In embodiments the circlip groove may comprise a second circlip abutment face on a side of the circlip groove furthest from the bearing abutment face, the second circlip abutment face extending in a perpendicular direction to a central axis of the bore.

[0016] Advantageously, a face of the circlip may abut the second circlip abutment face, in use, such that the centrifugal force acting on the circlip does not lead to axial movement of the bearing retention sleeve on the shaft.

[0017] In embodiments the circlip groove may comprise a second circlip abutment face on a side of the circlip groove furthest from the bearing abutment face, the second circlip abutment face being bevelled in a direction away from the radially inner surface and towards the bearing abutment face.

[0018] Advantageously, this circlip groove may reduce a risk that a circlip is installed incorrectly, because a circlip which is bevelled on both sides can be inserted. An angle between the circlip abutment face and the bearing abutment face may be between 12° and 18°. An angle between the circlip abutment face and the bearing abutment face may be between 14° and 16°. An angle between the circlip abutment face and the bearing abutment face may be 15°.

[0019] An angle between the second circlip abutment face and a second axial face of the bearing retention sleeve may be between 12° and 18°. An angle between the second circlip abutment face and a second axial face of the bearing retention sleeve may be between 14° and 16°. An angle between the second circlip abutment face and a second axial face of the bearing retention sleeve may be 15°.

[0020] In embodiments, the bearing retention sleeve may comprise a plurality of axial apertures extending to the circlip groove from a second axial face which is opposite to the bearing abutment face. The plurality of axial apertures may each be for receiving a tool to radially compress the circlip, for example in use.

[0021] The plurality of axial apertures may each be an axial channel or hole. The tool may comprise a rod with a chamfered or filleted end, such that the end progressively compresses the circlip as it is pushed into the aperture.

[0022] In embodiments, the bearing retention sleeve may comprise a plurality of radial apertures extending to the circlip groove from a radially outer face. The plurality of radial apertures may be for receiving a tool to radially compress the circlip, for example in use.

[0023] The plurality of radial apertures may be one or more radial channels or holes. The tool may comprise a rod which progressively compresses the circlip as it is pushed into the aperture.

[0024] The plurality of axial apertures may be at least three axial apertures. The plurality of radial apertures may be at least three radial apertures. The at least three axial apertures and / or the at least three radial apertures may be circumferentially evenly spaced around the bearing retention sleeve.

[0025] Advantageously, the circlip may be evenly compressed.

[0026] A distance between an axial face which is opposite to the bearing abutment face and the circlip groove may be greater than a distance between the bearing abutment face and the circlip groove. A distance between an axial face which is opposite to the bearing abutment face and the circlip groove may be less than a distance between the bearing abutment face and the circlip groove. A distance between an axial face which is opposite to the bearing abutment face and the circlip groove may be substantially equal to a distance between the bearing abutment face and the circlip groove. Advantageously, the circlip groove may be positioned such that stress concentrations are reduced in the bearing retention sleeve.

[0027] Another aspect of the invention provides a bearing retention system comprising: any of the aforementioned bearing retention sleeves; and a shaft received or receivable into the bore of the bearing retention sleeve, the shaft comprising a circlip groove for corresponding with the circlip groove of the bearing retention sleeve.

[0028] The shaft may be received or receivable in the bore of the sleeve with an interference fit or a transition fit.

[0029] It will be understood that a transition fit is a fit in which the diametric tolerance of the shaft and the diametric tolerance of the bearing retention sleeve bore is such that, when machined, the shaft may have a diameter which is smaller than the diameter of the bore, thus providing a clearance fit or the shaft may have a diameter which is greater than the diameter of the bore, thus providing an interference fit. It will be understood that an interference fit may otherwise be referred to as a press fit.

[0030] Advantageously, rattling may be reduced by the interference fit or transition fit and the bevelled groove, but the bearing retention sleeve is still removable from the shaft.

[0031] Alternatively, the shaft may be received or receivable in the bore of the sleeve with a press fit or an interference fit.

[0032] The bearing retention system may comprise a bevelled circlip received or receivable in the circlip groove of the shaft and in the circlip groove of the bearing retention sleeve, to retain the bearing retention sleeve on the shaft. Advantageously,...

[0033] The circlip may have an axial side having a bevelled face such that the circlip gets thinner with increasing radius, along the bevelled face. Therefore, when the bearing retention sleeve is used with a bevelled circlip, the aforementioned advantages may be realised.

[0034] The shaft may comprise a shoulder located such that, in use, a bearing is constrained between the shoulder and the bearing retention sleeve. Advantageously, the bearing may be axially captivated between the shoulder and the bearing retention sleeve.

[0035] The bearing retention system may comprise a helical gear mounted or mountable onto the shaft. The bearing retention system may comprise a bevel gear mounted or mountable onto the shaft.

[0036] The bearing system may be advantageous in that helical gears can generate significant axial forces, and so axial movement of the bearing is better prevented due to the cooperation between the bearing retention sleeve and the circlip.

[0037] Another aspect of the invention provides a bevelled circlip.

[0038] Another aspect of the invention provides a bevelled circlip for simultaneous receipt in a radially outer bevelled circlip groove and a radially inner circlip groove, the bevelled circlip comprising an axial side, the axial side having a bevelled face such that the circlip gets thinner with increasing radius along the bevelled face. Advantageously, when a shaft in which the radially inner circlip groove is received is rotated, centrifugal force which acts to radially expand the circlip may reinforce contact between the circlip and the bearing retention sleeve.

[0039] Either of the aforementioned bevelled circlip may comprise a radially inner edge, a radially outer edge and an axial side, the axial side having a bevelled face such that the circlip gets thinner with increasing radius, along the bevelled face.

[0040] The bevelled face of the axial side may be bevelled at an angle of between 12° and 18°, for example between 14° and 16°, for example 15°.

[0041] All points along the radially inner edge may be on a first reference circle. All points along the radially outer edge may be on a second reference circle.

[0042] Advantageously, the circlip may have no protrusions and so be usable with the aforementioned bearing retention sleeve and shaft.

[0043] The first reference circle and the second reference circle may be concentric.

[0044] Advantageously, contact between the radially inner edge and the shaft is consistent around the circumference of the circlip.

[0045] The axial side may be a first axial side, and the circlip may have a second axial side, a part of which corresponds radially to the bevelled face of the first axial side is perpendicular to a central axis of the circlip. Advantageously, the perpendicular part of the second axial side may reduce axial movement of the circlip in the groove.

[0046] The axial side may be a first axial side, and the circlip may have a second axial side, the second axial side having a bevelled face such that the circlip gets thinner with increasing radius, along the bevelled face.

[0047] The bevelled face of the second axial side may be bevelled at an angle of between 12° and 18°, for example between 14° and 16°, for example 15°.

[0048] The bevelled circlip may have a circumferential break with chamfered edges, such that end points on the radially outer edge are closer together than end points on the radially inner edge. Advantageously, the circlip may be contractable and expandable for removal and insertion into the groove, respectively.

[0049] Another aspect of the invention provides a vehicle differential comprising any of the aforementioned bearing retention sleeves, or the aforementioned bearing retention system.

[0050] The vehicle may be electric vehicle Another aspect of the invention provides a method of installing a bearing on a shaft which has a circlip groove on a radially outer surface, the method comprising: locating the shaft through a bore of the bearing; locating a bevelled circlip in the circlip groove of the shaft, the bevelled circlip comprising an axial side, the axial side having a bevelled face such that the circlip gets thinner with increasing radius, along the bevelled face; radially compressing the circlip into the circlip groove of the shaft; sliding a bearing retention sleeve onto the shaft and over the compressed circlip such that a bearing abutment face of the bearing retention sleeve is configured to be adjacent or to abut the bearing; aligning a circlip groove of the bearing retention sleeve with the compressed circlip, the circlip groove extending radially outwardly from a radially inner surface of the bearing retention sleeve, the circlip groove having a bevelled circlip abutment face on a side of the circlip groove nearest to the bearing abutment face, wherein the bevelled circlip abutment face is bevelled in a direction away from the radially inner surface and away from the bearing abutment face; and releasing the circlip such that the circlip expands into the circlip groove of the bearing retention sleeve, with the bevelled face of the circlip being adjacent or abutting the bevelled circlip abutment face of the circlip groove of the bearing retention sleeve.

[0051] Advantageously, the bearing retention sleeve may be axially constrained on the shaft with a bevelled circlip, with a bevel of the circlip abutting the bevelled circlip abutment face of the bearing retention sleeve. This may mean that, when the shaft is rotated and a centrifugal force causes the circlip to expand, the abutment of the bevelled faces reinforces the abutting contact between the bearing abutment face of the sleeve and the bearing. The may overcome the problem of external circlips becoming loose due to centrifugal forces. It will be appreciated that by centrifugal force it is meant an apparent force which acts to expand a rotating body, directed radially away from the centre of rotation.

[0052] Another aspect of the invention provides an axial tool for insertion into an axial aperture of a bearing retention sleeve which comprises a plurality of axial apertures extending to a circlip groove from a second axial face which is opposite to a bearing abutment face. The bearing retention sleeve may be any of the aforementioned bearing retention sleeves. Advantageously, the axial tool may be used for removing the bearing retention sleeve from the shaft.

[0053] The axial tool may comprise an insert portion. The insert portion may comprise a first end and a second end. The insert portion may comprise a compression side and a guide side. The guide side may be parallel to an intended axial direction when the axial tool is used with the bearing retention sleeve. The compression side may comprise a sloped or curved chape, such that a distance between the compression side and the guide side increases with distance from the first end of the insert portion to the second end of the insert portion. The first side of the insert portion may be inserted or insertable into the respective axial aperture first. Advantageously, the tool may provide a convenient method of removing the bearing retention sleeve from the shaft.

[0054] 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.

[0055] BRIEF DESCRIPTION OF THE DRAWINGS

[0056] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0057] Figure 1 shows a bearing retention system according to an embodiment of the invention;

[0058] Figure 2 shows a drivetrain including the bearing retention system of Figure 1 ;

[0059] Figure 3 shows a bevelled circlip used in the bearing retention system of Figure 1 ;

[0060] Figure 4 shows a bearing retention system according to an embodiment of the invention;

[0061] Figure 5 shows a bearing retention system according to an embodiment of the invention; Figure 6 shows a bearing retention sleeve with radial apertures for insertion of radial tools; Figure 7 shows another view of the bearing retention sleeve with radial apertures for insertion of radial tools, of Figure 6;

[0062] Figure 8 shows a bearing retention sleeve with axial apertures for insertion of axial tools;

[0063] Figure 9 shows an axial tool for use with the bearing retention sleeve of Figure 8; and Figure 10 shows a vehicle having the drivetrain of Figure 2.

[0064] DETAILED DESCRIPTION

[0065] With reference to Figure 1 , there is illustrated a schematic cross section of a portion of a bearing retention system 1 . The view in Figure 1 is a cross-section along an axial direction of the bearing retention system 1 , showing only one radial half of the bearing retention system. The bearing retention system 1 has a bearing retention sleeve 2, a bevelled circlip 3 and a shaft 4, which is received or receivable in a bore of the bearing retention sleeve 2. A circlip may also be called a retaining ring, or a snap ring, and typically consists of a flexible, resiliently deformable (e.g. metal) ring with open ends which can be snapped into place. The shaft 4 has a shoulder 41 and a circlip groove 42 for receiving the bevelled circlip 3. A bearing 5 is located on the shaft 4 such that a first axial side of the bearing 5 is axially constrained by the shoulder 41 , and another axial side of the bearing 5 is axially constrained by the bearing retention sleeve 2. The bearing retention sleeve 2 is axially constrained by the circlip 3 being received in a circlip groove 21 of the bearing retention sleeve 2. The bearing retention sleeve 2 is annular in shape and the bore of the bearing retention sleeve 2 is defined by a radially inner surface. The bearing retention sleeve 2 has a bearing abutment face 22 for axially abutting a part of a bearing 5 which is located on the shaft 4. The circlip groove 21 extends radially outwardly from the radially inner surface. The circlip groove 21 has a bevelled circlip abutment face 23 on a side of the circlip groove 21 nearest to the bearing abutment face 22. The bevelled circlip abutment face 23 is bevelled in a direction away from the radially inner surface and away from the bearing abutment face 22. In other words, the circlip abutment face 23 is angled, or chamfered, in a direction away from the radially inner surface and away from the bearing abutment face 22. In this example, an angle between the circlip abutment face 23 and the bearing abutment face 22 is between 12° and 18°, for example between 14° and 16°, for example 15°.

[0066] In this example, the circlip groove 21 has a second circlip abutment face 24 on a side of the circlip groove 21 furthest from the bearing abutment face 22, the second circlip abutment face 24 extending in a perpendicular direction to a central axis of the bore.

[0067] In this example, the shaft 4 is received (or receivable) in the bore of the bearing retention sleeve 2 with an interference fit, which may otherwise be referred to as a press fit. This is to prevent rattling of the bearing retention sleeve 2 on the shaft 4. In other examples, the shaft 4 is received (or receivable) in the bore of the bearing retention sleeve 2 with a transition fit. It will be understood that a transition fit is a fit in which the diametric tolerance of the shaft 4 and the diametric tolerance of the bore of the bearing retention sleeve 2 is such that, when machined, the shaft 4 may have a diameter which is smaller than the diameter of the bore, thus providing a clearance fit, or the shaft 4 may have a diameter which is greater than the diameter of the bore, thus providing an interference fit. This may mean that rattling is reduced by the transition fit, whilst still allowing removal of the bearing retention sleeve 2 from the shaft 4.

[0068] Referring now to Figure 2, the bearing retention system 1 in use in a vehicle drivetrain 6 is shown. In this example, the drivetrain 6 has a helical gear (not shown) and is a drivetrain in an electric vehicle. The bearing system may be advantageous in that helical gears can generate significant axial forces, and so axial movement of the bearing 5 is better prevented due to the cooperation between the bearing retention sleeve 2 and the circlip 3. In this example, the drivetrain 6 is a part of a vehicle differential, but it will be appreciated that it may be another part of the vehicle, that it may be for a component of a vehicle which is not in the drivetrain, and it may be for a vehicle which is not an electric vehicle. It will be appreciated that the bearing retention system 1 may instead be used with a bevel gear.

[0069] Referring now to Figure 3, alongside Figures 1 and 2, the bevelled circlip 3 is described. The bevelled circlip 3 may be otherwise referred to as a snap-ring, for example a metal snap-ring. The bevelled circlip 3 is for simultaneous receipt in the radially outer bevelled circlip groove 21 of the bearing retention sleeve 2 and the radially inner circlip groove 42 of the shaft 4.

[0070] The bevelled circlip 3 has a radially inner edge 31 , a radially outer edge 32 and a first axial side. The first axial side has a bevelled face 33 such that the circlip 3 gets thinner with increasing radius, along the bevelled face 33. In this example all points along the radially inner edge 31 are on a first reference circle (not shown). All points along the radially outer edge 32 are on a second reference circle (not shown). In this example, the first and second reference circles are concentric with one another, for example such that consistency of contact in the grooves is improved. It will be appreciated that the first and second reference circles are non-present construction, or artificial, circles.

[0071] In this example the bevelled circlip 3 has a circumferential break 34 with chamfered edges 341 , such that end points on the radially outer edge 32 are closer together than end points on the radially inner edge 31 .

[0072] The circlip 3 has a second axial side. In this example, a part of the circlip 3 on the second axial side which corresponds radially to the bevelled face 33 of the first axial side is perpendicular to a central axis of the circlip 3.

[0073] When in use, rotation of the shaft 4, circlip 3 and bearing retention sleeve 2 causes centrifugal forces to act on the circlip 3 and bearing retention sleeve 2 to cause them to expand radially. The bearing retention sleeve 2 is circumferentially continuous, and may be metallic, so the radial expansion is small or negligible. However, because the circlip has a circumferential break, which is used for installing the circlip into the grooves 21 , 42, the circlip expands radially due to this centrifugal force and so the bearing retention sleeve 2 prevents the circlip 3 from coming free from the shaft 4. Furthermore, the bevelled faces of the circlip 3 and bearing retention sleeve 2 reinforce axial restraint of the bearing 5. For example if the circlip 3 retained the bearing 5 directly, the circlip 3 might leave the circlip groove 42 of the shaft 4 altogether. However, the presence of the bearing retention sleeve 2 prevents this excessive radial expansion of the circlip 3. Furthermore, the abutment of the bevelled face 33 of the circlip 3 with the bevelled circlip abutment face 23 of the bearing retention sleeve 2 means that, when the circlip 3 radially expands due to centrifugal force, axial contact between the bearing abutment face 22 and the bearing 5 is reinforced.

[0074] The assembly of the bearing retention system 1 is now described. Firstly, the bearing 5 is assembled onto the shaft 5 such that the bearing abuts the shoulder 41 of the shaft 4. Next, the circlip 3 is radially expanded such that it passes over the shaft 4, and is installed into the circlip groove 42 of the shaft 4. Elasticity in the circlip 3 causes the circlip 3 to contract into the circlip groove 42.

[0075] Next, the circlip 3 is radially contracted such that the bearing retention sleeve 2 is able to pass over the circlip 3. Elasticity in the circlip means that the circlip radially expands into the circlip groove 21 of the bearing retention sleeve 2. It is necessary that the circlip 3 and bearing retention sleeve 2 are installed in the correct orientation, such that the bevelled faces abut one another.

[0076] Referring now to Figure 4, another example of a bearing retention system 10 is shown. The bearing retention system 10 of this example is similar to the bearing retention system 1 of the previous example, and similar features are denoted with the same reference numerals with a succeeding ‘O’.

[0077] In this bearing retention system 10 the second axial side of the bevelled circlip 30 has a bevelled face 350 corresponding to the bevelled face 330 of the first axial side. As in the previous example, the bearing retention sleeve 20 of this example has a bearing abutment face 220 for axially abutting a part of a bearing 50 which is located on a shaft 40. The circlip groove 210 extends radially outwardly from the radially inner surface. As in the previous example, the circlip groove 210 has a first bevelled circlip abutment face 230 on a side of the circlip groove 210 nearest to the bearing abutment face 220. The first bevelled circlip abutment face 230 is bevelled in a direction away from the radially inner surface and away from the bearing abutment face 220. In this example, an angle between the first bevelled circlip abutment face 230 and a radial direction of the bearing retention sleeve 20, or between the first bevelled circlip abutment face 230 and the bearing abutment face 220, is between 12° and 18°, for example between 14° and 16°, for example 15°.

[0078] This bearing retention system 10 differs from that of the previous example in that the circlip groove 210 of the bearing retention sleeve 20 has a second bevelled circlip abutment face 240 on a side of the circlip groove 210 furthest from the bearing abutment face 220. The second bevelled circlip abutment face 240 is bevelled in a direction away from the radially inner surface and towards the bearing abutment face 220. In this example, an angle between the second bevelled circlip abutment face 240 and a second axial side of the bearing retention sleeve 20, and a radial direction of the bearing retention sleeve 20 is between 12° and 18°, for example between 14° and 16°, for example 15°. The first and second bevelled circlip abutment faces 230, 240 may be mirrors of one another, such that they both have the same angles relative to the radial direction of the bearing retention sleeve 20.

[0079] In this example the circlip groove 210 of the bearing retention sleeve 20 is axially central in the bearing retention sleeve 20.

[0080] In this example, in use, the centrifugal force causes the circlip 30 to radially expand centrally into the circlip groove 210 of the bearing retention sleeve 20. This example has an advantage that the circlip 30 can be installed either way around, and so facilitates easier assembly. However, radial expansion of the circlip 30 may no longer reinforce contact between the bearing retention sleeve 20 and the bearing 50, at least to the same extent as the bearing retention system 1 of the previous example.

[0081] Furtehrmore, because the circlip groove 210 is located centrally along the length of the bearing retention sleeve 20, the bearing retention sleeve 20 can also be installed either way around to further simplify assembly of the bearing retention system 10.

[0082] Assembly of the circlip 30 and bearing retention sleeve 20 of this example is the same as in the previous example.

[0083] In Figure 4 is can be seen that a radially outermost part of the circlip groove 210 of the bearing retention sleeve 20 is parallel with a centreline of the bearing retention sleeve 20. However, the abutment faces may instead meet one other, and the corresponding circlip may have an edge defined between the two bevelled faces thereof. It will also be appreciated that the circlip groove 210 of the bearing retention sleeve 20 may not be located axially centrally in some examples, and still realise the advantage that the bevelled circlip 30 can be installed either way around.

[0084] Referring now to Figure 5, another example of a bearing retention system 10’ is shown. The bearing retention system 10’ of this example is similar to the bearing retention system 10 of the example of Figure 4, and similar features are denoted with the same reference numerals with a succeeding prime (‘).

[0085] In this bearing retention system 10’ bearing retention sleeve 20’ is the same as the bearing retention sleeve 2 of the first example, and similar features of the bearing retention sleeve 20’ are referred to with the same reference numerals as those in the first example, with a succeeding ‘0’ and prime (‘).

[0086] In this bearing retention system 10’ the second axial side of the bevelled circlip 30’ has a bevelled face corresponding to the bevelled face of the first axial side, as in the example of Figure 4. In this example, the second bevelled circlip abutment face 240’ is perpendicular to a central axis of the bearing retention sleeve 20’, as in the bearing retention sleeve 2 of the first example.

[0087] Risk of incorrect installation of the circlip and bearing retention sleeve may be different in different production lines. In a production line where there is a relatively low risk of installing the bearing retention sleeve 2 and circlip 3 the wrong way around, the bearing retention sleeve 2 and circlip 3 of the first example may be used. In a production line where there is a relatively high risk of installing the bearing retention sleeve 20 and circlip 30 the wrong way around, the bearing retention sleeve 20 and circlip 30 of the second example may be used. The bearing retention sleeve 20’ and circlip 30’ of this example may be used where there is a relatively high risk of installing the circlip 30’ the wrong way around, but a relatively low risk of installing the bearing retention sleeve 20’ the wrong way around. Due to bearing retention sleeve 2, 20’ being a larger component and, for example, may be easier to mark with an installation direction, it is expected that the risk of wrongly installing this will be relatively low in more production lines than the risk of installing the circlip 3, 30’ the wrong way around. Therefore, this example illustrates that the same bearing retention sleeve 2, 20’ may be used in two production lines with different risk profiles.

[0088] Assembly of the circlip 30’ and bearing retention sleeve 20’ of this example is the same as in the previous example.

[0089] Referring now to Figures 6 and 7, another example of a bearing retention sleeve 2’ is shown. The bearing retention sleeve 2’ is the same as any bearing retention sleeve 2, 20, 20’ described previously, with the exception that there are a plurality of radial apertures 25’ extending to the circlip groove from a radially outer face to allow the bearing retention sleeve 2’ to be removed from the shaft. In Figure 6 there is a radial tool TR shown located in one of the radial apertures 25’, and in Figure 7 there are radial tools TR located in each radial aperture 25’. In this example, there are four radial apertures 25’, but it will be apparent that any plurality can be used in order to radially compress the circlip. Each of the plurality of radial apertures 25’ is for receiving a radial tool TR to radially compress the circlip. The radial apertures 25’ are equally spaced around the circumference of the radially outer surface of the bearing retention sleeve 2’.

[0090] In use, a bearing retention system using this example of bearing retention sleeve 2’ is assembled as described previously.

[0091] To disassemble the bearing retention system, a radial tool TR is inserted into each radial aperture 25’. An force is applied to each radial tool TR along a radial direction of the bearing retention sleeve, for example along an axial direction of the tool, to radially compress the circlip such that the bearing retention sleeve 2’ can be moved over the circlip and removed from the shaft.

[0092] In this example the radial apertures 25’ are channels and the radial tools TR are rectangular in cross-section. However, it will be appreciated that this is merely representative, and the radial tools TR and radial apertures 25’ may have other cross-sectional shapes.

[0093] Referring now to Figure 8 there is shown another example of a bearing retention sleeve 2” is shown. The bearing retention sleeve 2” is the same as either bearing retention sleeve 2, 20 described previously, with the exception that there are a plurality of axial apertures 26” extending to the circlip groove from a second axial face which is opposite to the bearing abutment face. The plurality of axial apertures may each be for receiving a tool to radially compress the circlip, in use.

[0094] In this example, there are four axial apertures 26”, but it will be apparent that any plurality can be used in order to radially compress the circlip. Each of the plurality of axial apertures 26” is for receiving an axial tool TA (as shown in Figure 9) to radially compress the circlip, in use. The axial apertures 26” are equally spaced around the circumference of the radially inner face of the bearing retention sleeve 2”.

[0095] Referring now to Figure 9, an axial tool TA is shown. The axial tool has an insert portion TA1 and an attachment portion TA2 extending perpendicular to the insert portion TA1. However, the attachment portion TA2 is optional.

[0096] The insert portion TA1 has a first end and a second end, in this example the second end being connected to the attachment portion. The insert portion TA1 has a compression side TA11 and a guide side TA12. The guide side TA12 is parallel to an intended axial direction when the axial tool is used with the bearing retention sleeve 2”. The compression side TA11 has a sloped or curved chape, such that a distance between the compression side TA1 1 and the guide side TA12 increases with distance from the first end of the insert portion TA1 to the second end of the insert portion TA1 .

[0097] In use, an axial tool TA is used with each axial aperture 26” of the bearing retention sleeve 2”. The insert portion TA1 of each axial tool TA is inserted into the respective axial aperture 26” in the bearing retention sleeve 2”. The guide side TA12 slides along a radially outer surface of the respective axial aperture 26”. As the insert portion TA1 is pushed further into the respective axial aperture 26”, the compression side TA11 gradually compresses the circlip.

[0098] In some examples, the attachment portion TA2 is used to attach the axial tool TA to an actuator to push the axial tools TA into the axial apertures 26”.

[0099] In use, a bearing retention system using this example of bearing retention sleeve 2” is assembled as described previously.

[0100] To disassemble the bearing retention system, an axial tool TA is inserted into each axial aperture 26”. An axial force is applied to each axial tool TA to radially compress the circlip such that the bearing retention sleeve 2” can be moved over the circlip and removed from the shaft.

[0101] In this example the compression side TA11 of the axial tool TA is curved, but it will be appreciated that this may instead be a straight and angled side.

[0102] Figure 10 illustrates an electric vehicle 7 according to an embodiment of the present invention. The vehicle 7 comprises any of the aforementioned bearing retention system 1 , 10, 10’ and / or the drivetrain 6 as illustrated in Figure 2.

[0103] 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. For example, a distance between an axial face which is opposite to the bearing abutment face, and the circlip groove, may be greater than a distance between the bearing abutment face and the circlip groove. This may reduce stress concentrations in the example where there is only one bevelled face on the circlip. It will also be appreciated that the drivetrain 6 of Figure 2 may instead have the bearing retention system 10 of Figure 3. It will be further appreciated that the bearing retention systems of either of Figures 1 , 4 or 5 may have bearing retention sleeves of Figure 6 and 7 or of Figure 8.

Claims

CLAIMS1 . A bearing retention system comprising: a bearing retention sleeve; a bevelled circlip; and a shaft received or receivable into a bore of the bearing retention sleeve, the bore defined by a radially inner surface of the bearing retention sleeve, the bearing retention sleeve for axially constraining a bearing on the shaft, the bearing retention sleeve comprising: a bearing abutment face for axially abutting a part of a bearing which is located on the shaft; and a circlip groove extending radially outwardly from the radially inner surface, the circlip groove having a bevelled circlip abutment face on a side of the circlip groove nearest to the bearing abutment face, wherein the bevelled circlip abutment face is bevelled in a direction away from the radially inner surface and away from the bearing abutment face, the shaft comprising a circlip groove for corresponding with the circlip groove of the bearing retention sleeve, the bevelled circlip received or receivable in the circlip groove of the shaft and in the circlip groove of the bearing retention sleeve, to retain the bearing retention sleeve on the shaft.

2. A bearing retention system according to claim 1 , wherein the circlip groove comprises a second circlip abutment face on a side of the circlip groove furthest from the bearing abutment face, the second circlip abutment face extending in a perpendicular direction to a central axis of the bore.

3. A bearing retention system according to claim 1 , wherein the circlip groove comprises a second circlip abutment face on a side of the circlip groove furthest from the bearing abutment face, the second circlip abutment face being bevelled in a direction away from the radially inner surface and towards the bearing abutment face.

4. A bearing retention system according to any preceding claim, wherein an angle between the circlip abutment face and the bearing abutment face is between 12° and 18°.

5. A bearing retention system according to any preceding claim, wherein an angle between the circlip abutment face and the bearing abutment face is 15°.

6. A bearing retention system according to any preceding claim, comprising a plurality of axial apertures extending to the circlip groove from a second axial face which is opposite to the bearing abutment face, the plurality of axial apertures each for receiving a tool to radially compress the circlip.

7. A bearing retention system according to any preceding claim, comprising a plurality of radial apertures extending to the circlip groove from a radially outer face, the plurality of radial apertures for receiving a tool to radially compress the circlip.

8. A bearing retention system according to any previous claim, where the shaft is received or receivable in the bore of the sleeve with an interference fit.

9. A bearing retention system according to any previous claim, comprising a bearing mounted or mountable onto the shaft.

10. A bearing retention system according to any previous claim, comprising a helical gear mounted or mountable onto the shaft.

11. A bevelled circlip for simultaneous receipt in a radially outer bevelled circlip groove and a radially inner circlip groove, the bevelled circlip comprising an axial side, the axial side having a bevelled face such that the circlip gets thinner with increasing radius along the bevelled face.

12. A bevelled circlip according to claim 11 , wherein the axial side is a first axial side, and the circlip has a second axial side, a part of which corresponding radially to the bevelled face of the first axial side, is perpendicular to a central axis of the circlip.

13. A bevelled circlip according to claim 11 , wherein the axial side is a first axial side, and the circlip has a second axial side, the second axial side having a bevelled face such that the circlip gets thinner with increasing radius, along the bevelled face.

14. A vehicle differential comprising a bearing retention system according to any of claims 1 to 10.

15. A vehicle comprising a bearing retention system according to any of claims 1 to 10, or a vehicle differential of claim 14.

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