Bearing device with integrated electrical insulation and associated manufacturing method
By designing a slot-key structure of the insulating sleeve and bushing in the bearing device, the problem of current damage caused by potential difference in the electric motor is solved, and an economical and stable electrical insulation effect is achieved.
Patent Information
- Application Number
- CN202510422398.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-04-10
- Filing Date
- 2025-04-07
- Publication Date
- 2025-10-17
AI Technical Summary
Rolling bearings in existing electric motors or electric machines are damaged when rotating due to potential differences causing current to flow through the components, and known solutions such as ceramic rolling elements and insulating sleeves have problems such as high costs or the possibility of separation during operation.
A bearing device is designed, including an insulating sleeve and a bushing, wherein the insulating surface is overmolded on the second ring and is locked together by providing grooves and key structures on the bushing and the insulating surface to prevent separation, and electrical insulating materials are used to prevent current flow.
An economical and easy-to-manufacture electric insulating bearing device is realized, components are prevented from being damaged by electric current, relative movement between the insulating surface and the bushing is prevented when the temperature changes, and the stability of the device is improved.
Smart Images
Figure CN120798976A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present invention relates to the field of bearings, in particular for use in electric motors, electric machines and associated equipment. BACKGROUND
[0002] In an electric motor or machine, at least one rolling bearing is mounted between the casing of the electric motor or machine and the rotary shaft to support the shaft.
[0003] In operation, when the shaft rotates, a potential difference can arise between the shaft and the casing of the electric motor or machine, which generates an electric current between the inner ring, locked to the shaft, and the outer ring, locked to the casing, of the rolling bearing.
[0004] The current flowing through the constituent parts of the rolling bearing can damage said constituent parts, in particular the rolling elements and the races on the inner and outer rings. Discharges can also generate vibrations.
[0005] To remedy these drawbacks, it is known to replace the rolling elements of a bearing made of the same steel as the inner and outer rings with rolling elements made of ceramic. Such a bearing is therefore commonly referred to as a hybrid rolling bearing.
[0006] However, such hybrid rolling bearings are relatively expensive.
[0007] To remedy the above-mentioned drawbacks, it is also known to equip the outer ring of a rolling bearing with an insulating sleeve provided with a bushing and an insulating facing made of an electrically insulating material, arranged radially between the outer ring and the bushing.
[0008] The insulating facing can be overmoulded to fix the insulating facing to the outer ring and the bushing, without the need for additional constituent parts or specific machining of the outer ring.
[0009] However, with such a solution, relative separation of the insulating facing and the bushing can occur in operation.
[0010] The present invention therefore aims to remedy the above-mentioned drawbacks by proposing a bearing device with a simple and economical design. SUMMARY
[0011] The present invention relates to a bearing device comprising a bearing comprising a first race and a second race adapted to rotate relative to each other.
[0012] The device further comprises at least one insulating sleeve mounted on the second race of the bearing. The insulating sleeve comprises a bushing and an insulating facing arranged radially between the second race and the bushing. The insulating facing is made of an electrically insulating material.
[0013] The bushing comprises an outer surface delimiting a radial thickness of the bushing and an inner surface opposite the outer surface. The insulating facing is overmoulded onto the second race of the bearing and at least onto the outer surface and / or inner surface(s) of the bushing.
[0014] According to one general feature, at least one first groove is formed on the bushing.
[0015] According to another general feature, at least one first groove is formed on the insulating facing. This first groove of the insulating facing is positioned at least partially in radial alignment with the first groove of the bushing.
[0016] According to another general feature, the device further comprises at least one first key at least partially housed in the first groove of the bushing and of the insulating facing.
[0017] By "key at least partially housed in a groove", it is meant a key directly housed in the groove, or a key indirectly housed in the groove, with an intermediate element between them, for example a portion of the insulating facing.
[0018] Thus, a bearing device with integrated electrical insulation is obtained, which is economical compared to a conventional hybrid rolling bearing. Moreover, the device is easy to manufacture and assemble in an electric motor or associated electric machine.
[0019] Moreover, the provision of the first key makes it possible to lock the bushing and the insulating facing together in the circumferential direction. In the event of temperature variations, the risk of relative movement between the insulating facing and the bushing in the circumferential direction is significantly prevented.
[0020] By "circumferential direction", it is meant a direction which is both perpendicular to the axial direction and to the radius of the bearing device, in other words tangential to a circle with its centre on the axis of the bearing device.
[0021] By "axial direction", it is meant a direction parallel to the axis of the bearing device.
[0022] "key" means an element for locking together the bushing and the insulating face, the key can have a cross section of any shape, for example a polygonal shape, such as a square or rectangular shape, or a circular, oval, half-moon, etc. shape.
[0023] The first key can be made of an electrically insulating material.
[0024] As an alternative, the first key can be made of an electrically conductive material if it is surrounded at least at one end by an electrically insulating material.
[0025] In one particular design, at least one first slot can be formed on the second ring and positioned radially in line with the first slot of the insulating face.
[0026] In this case, advantageously, the first key can be at least partially housed in the first slot of the second ring. Thus, the bushing, the insulating face and the second ring of the bearing are locked together in the circumferential direction. The first slot on the second ring can open onto one of the front faces of the second ring.
[0027] The bushing can comprise two opposite radial front faces delimiting an axial length of the bushing. The insulating face can comprise two opposite radial front faces delimiting an axial length of the insulating face.
[0028] The first slot of the bushing can be formed on one of the front faces of the bushing.
[0029] The first slot of the insulating face can be formed on one of the front faces of the insulating face.
[0030] The first key can be flush with the front face of the bushing and the front face of the insulating face, or the first key remains setback relative to the front face of the bushing and the front face of the insulating face.
[0031] As an alternative, the first key can protrude axially relative to the front face of the bushing and the front face of the insulating face.
[0032] In this case, the first key can extend in a slot formed in a housing in which the bearing device is mounted. The first key forms a means for preventing the device from rotating relative to the housing.
[0033] The first key preferably comprises two opposite front faces delimiting a circumferential dimension of the first key. The front faces of the first key can be planar.
[0034] In a particular design, the device further comprises at least one second key housed at least partly in a second slot of the bushing and of the insulating face. The second slot in the insulating face is positioned at least partly radially co-linearly with the second slot in the bushing. The second key can be diametrically opposed to the first key.
[0035] The second key can be made of an electrically insulating material.
[0036] Alternatively, the second key can be made of an electrically conductive material if it is surrounded at one end at least by an electrically insulating material.
[0037] In other designs, the device can comprise only a first key or at least three keys, preferably spaced apart from each other in the circumferential direction.
[0038] Making the insulating face of a synthetic or elastic material makes it possible to make the device relatively insensitive to temperature variations.
[0039] In a particular embodiment, the bushing is made of metal. Thus, the bushing can be easily machined to a predetermined radial tolerance.
[0040] In one embodiment, the insulating face covers the entire said surface of the bushing. In this case, the insulating face covers the said surface of the bushing entirely in the axial direction and in the circumferential direction.
[0041] In a first design, the bushing delimits the outer surface of the device. In this case, the second ring is the outer ring of the bearing.
[0042] In an alternative second design, the bushing delimits the inner surface of the device. In this case, the second ring is the inner surface of the bearing.
[0043] In a particular embodiment, the bearing comprises at least one row of rolling elements arranged between the raceway of the first ring and the raceway of the second ring. The rolling elements can be made of metal.
[0044] The invention also relates to an electric motor comprising a casing, a shaft and at least one bearing device as defined above mounted radially between the casing and the shaft.
[0045] The invention also relates to a method of manufacturing a bearing device as defined above, the method comprising the following successive steps:
[0046] - mounting the bushing and at least the second ring in a mould,
[0047] - overmolding said insulating face onto said second ring and at least onto said surface of said bushing, and
[0048] - mounting said first key in said first slot of said insulating face and of said bushing.
[0049] The method can also comprise, after overmolding said insulating face and before mounting said first key, machining at least said first slot in said insulating face. Alternatively, at least the first slot can be obtained directly in the mold.
[0050] The application also relates to a method of manufacturing a bearing arrangement as defined above, said method comprising the following successive steps:
[0051] - machining at least said first slot of said bushing,
[0052] - mounting said first key in said first slot of said bushing,
[0053] - mounting said bushing equipped with said first key and at least said second ring in a mold, and
[0054] - overmolding said insulating face onto said second ring and at least onto said surface of said bushing.
[0055] The application also relates to a method of manufacturing a bearing arrangement as defined above, said method comprising the following successive steps:
[0056] - machining at least said first slot of said second ring,
[0057] - mounting said first key in said first slot of said second ring,
[0058] - mounting said bushing and at least said second ring equipped with said first key in a mold, and
[0059] - overmolding said insulating face onto said second ring, at least onto said surface of said bushing and onto said first key. BRIEF DESCRIPTION OF DRAWINGS
[0060] The application will be better understood in light of the detailed description of embodiments provided by way of non-limiting example and depicted in the attached drawings in which:
[0061] Figure 1 is a half-axial sectional view of a bearing arrangement according to a first embodiment of the application,
[0062] Figure 2 is a perspective view of a bearing arrangement from Figure 1
[0063] is a perspective view of a bearing arrangement fromFigure 3 is a detail view of Figure 2 ,
[0064] Figure 4 is a flowchart depicting a method of manufacturing a bearing arrangement from Figures 1 to 3 ,
[0065] Figure 5 is a half-axial sectional view of a bearing arrangement according to a second embodiment of the invention,
[0066] Figure 6 is a perspective view of a bearing arrangement from Figure 5 ,
[0067] Figure 7 is a half-axial sectional view of a bearing arrangement according to a third embodiment of the invention,
[0068] Figure 8 is a perspective view of a bearing arrangement from Figure 7 ,
[0069] Figure 9 is a detail view of Figure 8 ,
[0070] Figure 10 is a perspective view of a bearing arrangement from Figures 7 to 9 ,
[0071] Figure 11 is a flowchart depicting a method of manufacturing a bearing arrangement from Figures 7 to 10 ,
[0072] Figure 12 is a half-axial sectional view of a bearing arrangement according to a fourth embodiment of the invention,
[0073] Figure 13 is a perspective view of a bearing arrangement from Figure 12 ,
[0074] Figure 14 is a detail view of Figure 13 ,
[0075] Figure 15 is a perspective view of a bearing arrangement from Figures 12 to 14 ,
[0076] Figure 16 is a flowchart depicting a method of manufacturing a bearing arrangement from Figures 12 to 15 . DETAILED DESCRIPTION
[0077] Figure 1The depicted bearing arrangement comprises a bearing 10 comprising a first ring 12 and a second ring 14 which are able to rotate relative to each other about an axis X-X' of the bearing. In the depicted embodiment, the first ring 12 is the inner ring of the bearing and the second ring 14 is the outer ring.
[0078] The bearing arrangement is designed to not conduct electric current. The bearing arrangement contains integrated electrical insulation.
[0079] The inner ring 12 and the outer ring 14 of the bearing are concentric and extend in axial direction along the axis X-X' of the bearing. The inner ring 12 and the outer ring 14 are made of steel. The rings are of solid type.
[0080] In the depicted embodiment, the bearing 10 further comprises a row of rolling elements 16, here balls, arranged in radial direction between the inner ring 12 and the outer ring 14. The rolling elements 16 are made of steel. The bearing 10 further comprises a cage 17 to maintain a regular circumferential spacing of the rolling elements 16. The bearing 10 can further be equipped with a seal or sealing flanges.
[0081] The inner ring 12 comprises a cylindrical bore 12a, a cylindrical axial outer surface 12b opposite the bore in radial direction, and two opposite radial front faces (no reference number) axially delimiting the bore and the outer surface. The bore 12a and the outer surface 12b delimit a radial thickness of the inner ring 12. The bore 12a forms an inner surface of the inner ring.
[0082] The inner ring 12 further comprises an inner raceway 18 for the rolling elements 16 formed on the outer surface 12b. The raceway 18 points in radial direction outwards.
[0083] The outer ring 14 comprises a cylindrical axial outer surface 14a, a cylindrical bore 14b opposite the outer surface 14a in radial direction, and two opposite radial front faces 14c, 14d axially delimiting the bore. The outer surface 14a and the bore 14b delimit a radial thickness of the outer ring 14.
[0084] In the depicted embodiment, the outer surface 14a of the ring has two different diameters. Alternatively, the outer surface 14a can have only one diameter.
[0085] The outer ring 14 further comprises an outer raceway 20 for the rolling elements 16 formed in the bore 14b. The raceway 20 points in radial direction inwards.
[0086] In the depicted embodiment, the front face 14c of the outer ring is formed with a groove 22. The groove 22 is oriented to open in the axial direction to the exterior of the outer ring. The groove 22 has a bottom offset in the axial direction towards the interior of the ring with respect to the front face 14c. The bottom of the groove 22 forms a shoulder. Here, the bottom of the groove 22 extends in the radial direction to simplify manufacturing. Here, the groove 22 is annular.
[0087] Similarly, the front face 14d of the outer ring is formed with a groove 24. The groove 24 is oriented to open in the axial direction to the exterior of the outer ring. The groove 24 has a bottom offset in the axial direction towards the interior of the ring with respect to the front face 14d. The bottom of the groove 24 forms a shoulder. Here, the bottom of the groove 24 extends in the radial direction. Here, the groove 24 is annular. The grooves 22, 24 are symmetrical to each other with respect to the median radial plane of the outer ring. The grooves 22, 24 bound the outer surface 14a in the axial direction.
[0088] The bearing arrangement further comprises an electrically insulating sleeve 26 mounted on the outer ring 14. The insulating sleeve 26 is mounted on the outer surface 14a of the outer ring 14. The insulating sleeve 26 is locked to the outer ring 14.
[0089] The insulating sleeve 26 comprises a bushing 28 and an insulating facing 30 arranged in the radial direction between the outer ring 14 and the bushing 28. The insulating facing 30 is overmolded on the outer ring 14 and the bushing 28.
[0090] As described in more detail hereafter, the bearing arrangement further comprises a first key 32 and a second key 33 to constrain the bushing 28 and the insulating facing 30 to rotate together.
[0091] The bushing 28 has an annular shape. The bushing 28 extends in the axial direction. Here, the bushing 28 is made in one piece. Alternatively, the bushing 28 can be made in the form of several parts (for example two identical parts) pressed together. The bushing 28 has a cylindrical annular axial outer surface 28a and an annular bore 28b opposite in the radial direction to the outer surface 24a. The bore 28b forms an inner surface of the bushing 24. The bore 28b is oriented in the radial direction inwardly (i.e. on the side of the outer ring 14).
[0092] The bushing 28 further has two opposite radial front faces 28c, 28d bounding the bore and the outer surface in the axial direction. The front faces 28c, 28d bound the axial length of the bushing. The outer surface 28a and the bore 28b bound the radial thickness of the bushing 24. The outer surface 28a of the bushing bounds the outer surface of the bearing arrangement 10. In other words, the outer surface 28a defines the outer diameter of the bearing arrangement 10.
[0093] In the depicted embodiment, the front faces 28c, 28d of the bushing are coplanar with the front faces 14c, 14d of the outer ring, respectively. As an alternative, other configurations can be provided. For example, the bushing 28 can have a smaller or larger axial dimension and remain recessed or protruding in axial direction from the faces 14c, 14d of the outer ring.
[0094] With reference to Figure 3 A first groove 34 is formed on the bushing. The first groove 34 is formed on the front face 28d of the bushing. The groove 34 is oriented opening outwards in axial direction. The groove 34 opens in radial direction to the bore 28b of the bushing. In the depicted embodiment, the groove 34 also opens in radial direction to the outer surface 28a of the bushing.
[0095] The groove 34 is delimited in circumferential direction by two facing lateral flanks (lateral flanks) 34a, 34b connected to each other by a radial bottom 34c. Here, the flanks 34a, 34b are rectilinear and extend in radial direction. The bottom 34c also extends in radial direction and is oriented outwards in axial direction. As an alternative, the groove 34 can be devoid of bottom, the flanks 34a, 34b being then directly connected.
[0096] In the depicted embodiment, a first groove 36 is formed on the outer ring. The groove 36 is formed on the outer surface of the groove 22 on the outer ring and opens to the front face 14d. The groove 36 opens outwards in axial direction. The groove 36 is oriented opening outwards in radial direction.
[0097] The groove 36 is delimited in circumferential direction by two facing lateral flanks 36a, 36b connected to each other by a radial bottom (not visible). The groove 36 also comprises an axial bottom 36c connected to the flanks 36a, 36b and to the radial bottom. Here, the flanks 36a, 36b are rectilinear and extend in radial direction. The radial bottom also extends in radial direction and is oriented outwards in axial direction. As an alternative, the groove 36 can be devoid of bottom, the flanks 36a, 36b being then directly connected.
[0098] The insulating face 30 is made of an electrically insulating material. The insulating face 30 can for example be made of a synthetic material such as PEEK or PA46 or an elastomeric material, for example rubber.
[0099] With reference to Figures 1 to 3 The insulating face 30 is arranged in radial direction between the outer surface 14a of the outer ring and the bore 28b of the bushing. The insulating face 30 covers the outer surface 14a of the outer ring. Here, the insulating face 30 covers the outer surface 14a completely in axial direction and in circumferential direction. The insulating face 30 also covers the grooves 22, 24 of the outer ring. The insulating face 30 also covers the groove 36 of the outer ring. The insulating face 30 covers the flanks 36a, 36b as well as the axial bottom and the radial bottom of the groove 36.
[0100] The insulating face 30 also covers the bore 28b of the bushing. Here, the insulating face 30 also entirely covers the bore 28b in the axial direction and in the circumferential direction. The insulating face 30 also covers the groove 34 of the bushing. The insulating face 30 covers the side faces 34a, 34b and the bottom 34c of the groove.
[0101] The insulating face 30 has an annular shape. The insulating face 30 extends in the axial direction. The insulating face 30 comprises a cylindrical axial outer face 30a, a cylindrical bore 30b diametrically opposite the outer face 30a and two opposite radial front faces 30c, 30d delimiting the bore and the outer face in the axial direction. The radial front faces 30c, 30d delimit the axial length of the insulating face 30. The outer face 30a is in radial contact with the bore 28b of the bushing. The portion of the insulating face 30 covering the groove 34 forms a protrusion extending radially outwards. The bore 30b is in radial contact with the outer face 14a of the outer ring, the grooves 22, 24 and the axial bottom 34c of the groove 34. The bore 30b has a stepped shape. The portion of the insulating face 30 covering the groove 36 forms a protrusion extending radially inwards.
[0102] In the depicted embodiment, the respective faces 14c, 30c, 28c and 14d, 30d, 28d of the outer ring, the insulating face and the bushing are coplanar.
[0103] As an alternative, other configurations can be used. For example, the insulating face 30 can have a smaller axial dimension and remain set back in the axial direction from the faces 14c, 14d of the outer ring. As an alternative, the insulating face 30 can have an increased axial dimension and protrude in the radial direction from the faces 14c, 14d of the outer ring. In this case, the insulating face 30 can at least partially cover these faces 14c, 14d. As an alternative, the insulating face 30 can at least partially cover the faces 28c, 28d of the bushing.
[0104] As an alternative or in combination, the bushing 28 can protrude in the axial direction from the insulating face 30 relative to the faces 30c and 30d or remain set back from said faces in the axial direction.
[0105] The insulating face 30 also comprises a first groove 40 formed in the portion of the insulating face covering the groove 24 of the bushing and forming an outer protrusion. This groove 40 extends within the radial thickness of the insulating face. The groove 40 extends radially inwards to the vicinity of the outer face 30b of the outer ring. The groove 40 opens radially outwards. The groove 36 is positioned in radial line with the groove 40. The groove 40 is oriented to open axially outwards. The groove 40 opens onto the front face 30d of the insulating face.
[0106] The groove 40 is delimited in the circumferential direction by two facing lateral flanks 40a, 40b connected to each other by a radial bottom 40c. Here, the flanks 40a, 40b are rectilinear and extend in the radial direction. The bottom 40c also extends in the radial direction and is oriented axially outwardly. Alternatively, the groove 40 can be devoid of bottom, the flanks 40a, 40b being then directly connected. The groove 40 further comprises an axial bottom 40d connected to the flanks 40a, 40b and to the radial bottom 40c.
[0107] As indicated above, the bearing arrangement comprises a first key 32. The key 32 is mounted in the groove 40 of the insulating face. The key 32 is indirectly mounted in the groove 34 of the bushing, there being between them the part of the insulating face delimiting the groove 40.
[0108] The key 32 bears in the circumferential direction against the flanks 40b, 40c of the groove 40 of the insulating face. The key 32 bears in the axial direction against the bottom 40c of the groove.
[0109] The key 32 has two lateral flanks 32a, 32b bearing in the circumferential direction against the flanks 40b, 40c, respectively. The faces 32a, 32b delimit the circumferential dimension of the key 32. Here, the key 32 is a parallel type key. Alternatively, the key 32 can have other shapes, and for example the faces 32a, 32b can be non-parallel, in particular dovetail type or with a stepped profile. The key 32 can also have a cylindrical or other shape.
[0110] The key 32 also has an inner face 32c bearing in the radial direction against the axial bottom 40c of the groove and an opposite exterior face 32d. The faces 32c, 32d delimit the radial height of the key 32. Here, the exterior face 32d is set back in the radial direction from the outer surface 28a of the outer ring. Alternatively, the exterior face 32d of the key can be flush with the outer surface 28a.
[0111] The key 32 can be fixed in the groove 40 by any appropriate means, for example by force fit, by gluing, by adhesive bonding, by overmoulding, by dual injection moulding, etc. Alternatively, the key 32 can be freely mounted in the groove 40.
[0112] In the depicted embodiment, the key 32 is flush with the front face 28d of the bushing and with the front face 30d of the insulating lining. Alternatively, the key 32 can remain recessed with respect to the front face 28d of the bushing and to the front face 30d of the insulating lining, or axially protruding with respect to said faces, as depicted in the embodiments from Figure 5 and Figure 6 .
[0113] As indicated above, the bearing arrangement further comprises a second key 33. The second key 33 is identical to the first key 32 and diametrically opposite. The key 33 is mounted on the bushing 28 and on the insulating lining 30 in exactly the same way as the first key 32, and this will not be described in more detail.
[0114] Here, the first key 32 and the second key 33 are made of an electrically insulating material. The keys 32, 33 can for example be made of a synthetic material such as PEEK or PA46, or of an elastomeric material such as rubber. Alternatively, the first key 32 and the second key 33 can be made of an electrically conductive material and at least surrounded by an electrically insulating material at one end.
[0115] The bearing arrangement is manufactured in the following way.
[0116] In a first step 50 depicted in Figure 4 , the grooves 34 and the groove diametrically opposite to the bushing 28 (not referenced) are machined. The grooves 36 and the groove diametrically opposite to the outer ring 14 (not referenced) are also machined.
[0117] In a successive second step 52, the bearing 10 and the bushing 28 are installed in a mold for overmolding the insulating lining 30. In this position installed in the mold, the bushing 28 is radially at a distance from the outer ring 14 of the bearing.
[0118] In a successive third step 54, the insulating lining 30 is overmolded onto the outer ring 14 of the bearing and onto the bushing 28.
[0119] Then, in a fourth step 56, the whole assembly formed by the bearing 10, the bushing 28 and the insulating lining 30 is extracted from the mold.
[0120] Then, in a successive fifth step 58, the grooves 40 and the groove diametrically opposite to the insulating lining (not referenced) are machined. Alternatively, said grooves can be produced directly in the mold.
[0121] Finally, in a sixth step 59, the first key 32 and the second key 33 are installed in the grooves of the insulating lining.
[0122] The first key 32 and the second key 33 are inserted in the slot of the insulating face in the axial direction. Alternatively, the first key 32 and the second key 33 can be inserted in the slot of the insulating face in the radial direction, for example if the slot is not open on one side of the device in the axial direction.
[0123] Figures 7 to 10 The embodiment depicted in which identical elements have identical reference numerals differs from the first embodiment mainly in that the keys 32 are mounted directly in the slot 34 of the bushing. Thus, in this example, the keys 32 are mounted directly in the slot 34 of the bushing and directly in the slot 40 of the insulating face. The keys 32 are mounted so as to bear in the axial direction against the bottom of the slots 34, 40.
[0124] In this embodiment, the radial dimension of the slot 40 of the insulating face 30 is reduced. The slot 40 is positioned so as to be collinear in the radial direction with the slot 34. The sides 40a, 40b of the slot 40 extend respectively radially inwards from the sides 34a, 34b of the slot 34. The keys 32 bear in the circumferential direction against the sides 34a, 34b of the slot 34 and against the sides 40b, 40c of the slot 40.
[0125] As in the first embodiment, the key 33 is mounted in exactly the same way as the first key 32.
[0126] The bearing device is manufactured in the following way.
[0127] In the first step 60 depicted in Figure 11 In a first step 60 depicted in
[0128] In a successive second step 62, the keys 32, 33 are mounted in the said slot of the bushing 28. Thus, the bushing 28 supports the keys 32, 33.
[0129] Then, in a third step 64, the bearing 10 and the bushing 28 are mounted in a mould for overmoulding the insulating face 30. In this position mounted in the mould, the bushing 28 and the keys 32, 33 are at a distance in the radial direction from the outer ring 14 of the bearing.
[0130] Then, in a successive fourth step 66, the insulating face 30 is overmoulded onto the outer ring 14 of the bearing, the bushing 28 and the keys 32, 33.
[0131] Finally, in a fifth step 68, the bearing device in the form of a unitary assembly is extracted from the mould.
[0132] Figures 12 to 15 The embodiment depicted, in which identical elements bear identical reference numerals, differs from the first embodiment in that the key 32 is mounted in the groove 36 of the outer ring.
[0133] In this embodiment, the groove 36 is in line with the groove 40 in the radial direction. The flanks 36a, 36b of the groove 36 extend radially inwards from the respective flanks 40a, 40b of the groove 40. The groove 36 opens out in the radial direction to the bore 14b of the outer ring. The key 32 bears in the circumferential direction against the flanks 36a, 36b of the groove 36 and the flanks 40b, 40c of the groove 40. The key 32 is mounted so as to bear in the axial direction against the bottoms of the grooves 36, 40.
[0134] In this embodiment, the insulating face 30 covers the upper face of the key 32. The insulating face 30 also covers the entire groove 40 and is flush with the outer face 28 of the bushing.
[0135] As in the first embodiment, the key 33 is mounted in exactly the same way as the first key 32.
[0136] The bearing arrangement is manufactured in the following way.
[0137] In Figure 16 In a first step 70 depicted in the figure, the grooves 36 for mounting the first key 32 and the second key 33 and the groove (not referenced) diametrically opposite the outer ring 14 are machined. The groove 34 and the groove (not referenced) diametrically opposite the bushing are also machined.
[0138] In a successive second step 72, the keys 32, 33 are mounted in the grooves of the outer ring 14. The outer ring 14 thus supports the keys 32, 33 at this stage.
[0139] Then, in a third step 74, the bearing 10 and the bushing 28 are mounted in a mould for overmoulding the insulating face 30. In this position mounted in the mould, the bushing 28 is at a distance in the radial direction from the outer ring 14 of the bearing.
[0140] Then, in a successive fourth step 76, the insulating face 30 is overmoulded onto the outer ring 14 of the bearing, onto the bushing 28 and onto the keys 32, 33.
[0141] Finally, in a fifth step 78, the bearing arrangement, in the form of a monobloc assembly, is extracted from the mould.
[0142] In the embodiment depicted, the first ring 12 of the bearing is an inner ring and the second ring 14 onto which the insulating face 30 is overmoulded is an outer ring.
[0143] As an alternative, the opposite configuration can be adopted, in which the second ring 14 onto which the insulating face 30 is overmoulded is the inner ring. In this case, the insulating sleeve is located in the bore 12a of the inner ring. The insulating face is then arranged radially between the bore 12a of the inner ring and the outer surface of the bushing. The insulating face is overmoulded onto the inner ring and at least onto the outer surface of the bushing. The bore of the bushing delimits the bore of the bearing device.
[0144] In the described embodiment, the bearing of the device has only one row of rolling elements. As an alternative, the bearing can comprise several rows of rolling elements. Moreover, the rolling bearing can comprise other types of rolling elements than balls, such as rollers, for example. In another variant, the bearing can be a sliding bearing without rolling elements.
Claims
1. A bearing device comprising a bearing (10), the bearing (10) comprising a first ring (12) and a second ring (14) adapted to rotate relative to each other, and an insulating sleeve (26) mounted on the second ring (14) of the bearing, the insulating sleeve (26) comprising a bushing (28) and an insulating surface (30), the insulating surface (30) being arranged radially between the second ring (14) and the bushing (28) and being made of an electrically insulating material, the bushing comprising an outer surface (28a) defining a radial thickness of the bushing and an inner surface (28b) opposite the outer surface, the insulating surface (30) being overmolded onto the second ring (14) of the bearing and onto the outer surface and / or inner surface of the bushing (28), characterized in that At least one first groove (34) is formed in the bushing (28), at least one first groove (40) is formed in the insulating surface (30), the first groove (40) of the insulating surface being positioned to at least partially align radially with the first groove (34) of the bushing, and the device further includes at least one first key (32) at least partially received in the first grooves (34, 40) of the bushing and the insulating surface.
2. The device according to claim 1, characterized in that The device further comprises at least one first groove (36) formed on the second ring (14) and positioned radially co-linear with the first groove (40) of the insulating face, the first key (32) being at least partially received in the first groove (36) of the second ring.
3. The device according to claim 2, characterized in that The first groove (36) of the second ring opens to one of the front faces (14d) of the second ring.
4. The device according to any one of the preceding claims, characterized in that The bushing (28) includes two opposite radial front faces (28c, 28d) defining the axial length of the bushing, the insulating surface (30) includes two opposite radial front faces (30c, 30d) defining the axial length of the insulating surface, and the first groove (34) of the bushing is formed on one of the front faces (28d) of the bushing, and the first groove (40) of the insulating surface is formed on one of the front faces (30d) of the insulating surface.
5. The device according to claim 4, characterized in that The first key (32) is flush with the front face (28d) of the bushing and the front face (30d) of the insulating surface, or the first key (32) remains set back relative to the front face (28d) of the bushing and the front face (30d) of the insulating surface, or the first key (32) protrudes axially relative to the front face of the bushing and the front face of the insulating surface.
6. A method of manufacturing a bearing device according to any one of claims 1 to 5, comprising the following successive steps: - installing said bushing (28) and at least said second ring (14) in a mould, - overmolding the insulating surface (30) onto the second ring (14) and at least onto the surface of the bushing (28), and - Installing the first key (32) in the first groove (34, 40) of the insulating surface and the bushing.
7. A method of manufacturing a bearing device according to any one of claims 1 to 5, the method comprising the following successive steps: - machining at least a first groove (34) of said bushing, - installing the first key (32) in the first groove (34) of the bushing, - installing the bushing (28) equipped with said first key and at least said second ring (14) in a mould, and - Overmolding the insulating surface (30) onto the second ring (14), at least onto the surface of the bushing (28) and onto the first key (32).
8. A method of manufacturing a bearing device according to claim 2 or 3, or claim 4 or 5 when dependent on claim 2, comprising the following successive steps: - machining at least said first groove (36) of said second ring, - installing the first key (32) in the first groove (36) of the second ring, - installing said bushing (28) and said second ring (14) equipped with at least said first key in a mould, and - Overmolding the insulating surface (30) onto the second ring (14), at least onto the surface of the bushing (28) and onto the first key (32).
9. An electric motor comprising a housing, a shaft and at least one bearing device according to any one of claims 1 to 5, the bearing device being mounted radially between the housing and the shaft.