Bearing device with integrated electrical insulation, especially for an electric motor or machine

Abstract

The bearing device comprises a bearing 10, which is provided with a first ring 12 and a second ring 14, which are able to rotate relative to each other. The device comprises at least one insulating sleeve 26, which is attached to the second ring 14 of the bearing and is provided with a bushing 28 and an insulating insert 30, which is inserted radially between the second ring 14 and the bushing 28 and is made of electrically insulating material. The bushing comprises an outer surface 28a and an inner surface 28b, which limit its radial thickness. The insulating insert 30 is overmolded onto the second ring 14 of the bearing and onto at least one of the outer and inner surfaces of the bushing 28. The bushing 28 is made of at least two first and second parts 32, 34, each part comprising an axial section 32a, 34a and a radial shoulder 32b, 34b which extends the axial section radially towards the inside.

Description

Technical field of the invention

[0001] The present invention relates to the field of bearings, which are used in particular in electric motors, electric machines and related equipment. State of the art

[0002] In an electric motor or electric machine, at least one rolling bearing is attached between the housing of the electric motor or electric machine and the rotating shaft to support this shaft.

[0003] During operation, when the shaft is rotating, a difference in electrical potential can occur between the shaft and the housing of the electric motor or electric machine, which generates an electric current between the inner ring of the rolling bearing, which is attached to the shaft, and the outer ring, which is attached to the housing.

[0004] The electric current flowing through the bearing components can destroy them, especially the rolling elements and the raceways formed on the inner and outer rings. Electrical discharges can also cause vibrations.

[0005] To overcome these disadvantages, it is known to replace the bearing's rolling elements, which are made of the same steel as the inner and outer rings, with rolling elements made of ceramic. This is generally referred to as a hybrid rolling bearing.

[0006] However, such a hybrid roller bearing is relatively expensive.

[0007] To overcome the aforementioned disadvantages, it is also known to provide the outer ring of the rolling bearing with an insulating sleeve, which is equipped with a bushing and an insulating insert made of electrically insulating material and which is inserted radially between the outer ring and the bushing.

[0008] To implement the attachment of the insulating insert to the outer ring and the bushing without additional elements or special machining of the outer ring, it is possible to overmold the insulating insert.

[0009] However, with such a solution, a relative separation of the insulating insert and the outer ring can occur during operation.

[0010] The present invention therefore aims to eliminate the aforementioned disadvantages by proposing a storage device of simple and economical design. Summary of the invention

[0011] The invention relates to a bearing device comprising a bearing provided with a first ring and a second ring which are able to rotate relative to each other.

[0012] The device also includes at least one insulating sleeve attached to the second ring of the bearing. The insulating sleeve is provided with a bushing and an insulating insert, which is radially inserted between the second ring of the bearing and the bushing. The insulating insert is made of electrically insulating material.

[0013] The bushing comprises an outer surface and an inner surface opposite the outer surface, which define the radial thickness of the bushing.

[0014] The second ring comprises an outer surface and an inner surface opposite the outer surface, which limit the radial thickness of the second ring, and a first and a second end face, which limit the axial length of the second ring.

[0015] The insulating insert is overmolded onto at least one of the outer and inner surfaces of the second ring of the bearing and onto at least one of the outer and inner surfaces of the bushing.

[0016] According to a general characteristic, the bushing is manufactured in at least two separate first and second parts, each comprising an axial section and a radial shoulder that extends the axial section at least radially inwards.

[0017] According to another general feature, the axial sections of the first and second parts together at least partially define the area of ​​the bushing on which the insulating insert is overmolded.

[0018] According to another general feature, at least the radial shoulder of the first part of the bushing extends radially beyond the outer surface or the inner surface of the second ring on which the insulating insert is overmolded, and is provided with several through holes spaced apart relative to each other in the circumferential direction.

[0019] According to another general feature, the insulating insert is also overmolded on an inner surface of the radial shoulder of each of the first and second parts of the bushing and at least partially overmolded on the first and second end faces of the second ring.

[0020] According to another general feature, the insulating insert comprises a group of blind holes, each extending axially within one of the through holes of the radial shoulder of the first part of the bushing and remaining axially spaced from the first end face of the second ring.

[0021] Manufacturing the two parts of the bushing with radial shoulders allows for effective attachment to the insulating insert. This avoids the risk of relative displacement between the insulating insert and the bushing in the axial direction, particularly in the case of temperature fluctuations.

[0022] “Axial direction” should be understood as the direction parallel to the axis of the bearing device.

[0023] Furthermore, compared to a one-piece manufacturing of the shouldered bushing, manufacturing it in at least two separate parts facilitates the placement of the second ring within the mold provided for overmolding the insulating insert.

[0024] Furthermore, considering the dimensioning of the radial shoulder of the first part of the bushing, the portion of the insulating insert located axially between the second ring and this radial shoulder is not subjected to shear stresses when significant axial loads act on the device, which is mounted in the housing of the motor or electrical machine connected to this shoulder, which rests against a shoulder of the housing. More precisely, compressive stresses are exerted on this portion of the insulating insert in this case. This increases the reliability of the device.

[0025] Each blind hole in the insulating insert corresponds to the bearing surface of the injection nozzle used when overmolding the insulating insert during the manufacturing of the bearing assembly. Injecting material through the through-holes of the radial shoulder of the first part of the bushing allows for an increase in the radial dimension of this shoulder and the bearing surface within the housing of the motor or associated electrical machine. This also allows for a reduction in the volume of the insulating insert material, which is more expensive than the bushing material.

[0026] In one particular embodiment, the insulating insert covers the bore of each of the multiple through-holes in the radial shoulder of the first part of the bushing. Alternatively, the insulating insert could also cover only the bore of some of the multiple through-holes.

[0027] Preferably, the radial shoulder of the second part of the bushing extends radially beyond the outer or inner surface of the second ring on which the insulating insert is overmolded. Alternatively, it is possible to provide that the radial shoulder of the second part of the bushing remains radially retracted from the outer or inner surface of the second ring on which the insulating insert is overmolded.

[0028] Advantageously, the radial shoulder of the second part of the bushing is provided with several through holes spaced relative to each other in the circumferential direction. In this case, the insulating insert can comprise a group of through holes, each extending axially within one of the through holes and opening into the second end face of the second ring.

[0029] Each through-hole of the insulating insert corresponds to the positioning of a pin, which enables the centering of the second part of the bushing and the transmission of the clamping forces of the mold used during the overmolding of the insulating insert.

[0030] Positioning the pins through the through-holes of the radial shoulder of the second part of the bushing allows for an increase in the radial dimension of this shoulder and the bearing surface in contact with the housing of the motor or associated electrical machine. This further reduces the volume of insulating material.

[0031] According to a particular embodiment, the insulating insert covers the bore of each of the multiple through-holes of the radial shoulder of the second part of the bushing. Alternatively, the insulating insert could cover only the bore of some of the multiple through-holes of the radial shoulder of the second part of the bushing.

[0032] According to a specific embodiment, the insulating insert can comprise at least one bolt between two circumferentially consecutive through-holes of the insulating insert, extending within one of the through-holes of the radial shoulder of the second part of the bushing. Alternatively, the bolt distribution can be different. In another embodiment, the insulating insert may have no bolt if a centering pin is provided to be accommodated in each through-hole of the radial shoulder of the second part of the bushing.

[0033] In one embodiment, the first and second parts of the bushing are symmetrical with respect to a radial median plane of the device. This makes it possible to reduce the manufacturing costs of the device.

[0034] According to a particular embodiment, the axial sections of the first and second parts of the bushing are in axial contact with each other and together define the entire area of ​​the bushing on which the insulating insert is overmolded.

[0035] According to a further embodiment, the axial sections of the first and second parts of the bushing are axially spaced apart. In this case, the bushing can also include an additional ring that is inserted axially between the axial sections of the first and second parts of the bushing and, together with the axial sections of the first and second parts of the bushing, defines the area of ​​the bushing on which the insulating insert is overmolded.

[0036] According to a specific embodiment, the surface of the socket is provided with at least one circumferentially extending groove in which an engagement rib of the insulating insert of complementary shape extends.

[0037] This increases the axial engagement of the insulating insert in the bushing.

[0038] The term "circumferential direction" is understood to mean the direction that is perpendicular to both the axial direction and a radius of the bearing device, in other words tangential to a circle whose center lies on the axis of the bearing device.

[0039] Each axial section of the first and second part of the bushing can be provided with at least one circumferentially extending groove in which an engagement rib of the insulating insert of complementary shape extends.

[0040] If the insulating insert is made of synthetic or elastomeric material, it makes the device insensitive to temperature fluctuations.

[0041] In a particular embodiment, the first and second parts of the bushing are made of metallic material. The bushing can therefore be easily machined to a predetermined radial tolerance.

[0042] The first and second parts of the bushing can be obtained from a sheet metal blank by cutting, punching and rolling.

[0043] In one embodiment, the insulating insert covers the entire surface of the bushing. In this case, the insulating insert completely covers the surface of the bushing in both the axial and circumferential directions.

[0044] According to a first embodiment, the bushing defines the outer surface of the device. In this case, the second ring is the outer ring of the bearing.

[0045] According to a second alternative embodiment, the bushing defines the inner surface of the device. In this case, the second ring is the inner ring of the bearing.

[0046] In a particular embodiment, the bearing comprises at least one series of rolling elements arranged between the raceways of the first and second rings. The rolling elements can be made of metallic material.

[0047] The invention further relates to an electric motor comprising a housing, a shaft and at least one bearing device as defined above and mounted radially between the housing and the shaft.

[0048] The invention further relates to a method for manufacturing a bearing device as defined above, comprising: - a step of attaching one of the first and second parts of the bushing to the bottom of a manufacturing mold, - a step of placing the second ring within the manufacturing mold, - one step of attaching the other of the first and second parts of the bushing within the manufacturing mold, - a step of placing injectors in the through holes of the radial shoulder of the first part of the bushing, the injectors remaining axially at a distance from the first end face of the second ring, - a step of overmolding the insulating layer using the injection nozzles and - a step of assembly with the first ring of the bearing of the arrangement formed by the second ring, the first and second part of the bushing and the insulating insert.

[0049] The process may also include, prior to the overmolding step, a step of inserting centering bolts into the through holes of the radial shoulder of the second part of the bushing, with the bolts bearing axially against the second end face of the second ring. Brief character description

[0050] The present invention will be understood more clearly when the detailed description of an embodiment provided as a non-limiting example and illustrated by the accompanying drawings is studied, in which: [ Fig. 1] a front view of a storage device according to an exemplary embodiment of the invention is, [ Fig. 2] a half-view in section along axis II-II of the Fig. 1 is, [ Fig. 3] a half-view in section along axis III-III of the Fig. 1 is, [ Fig. 4] A perspective partial exploded view of the storage device of the Fig. 1 is, in which an insulating insert of the device is not shown, and [ Fig. 5] is a flowchart that shows the procedure for manufacturing the bearing device of the Fig. 1 represents. Detailed description of the invention

[0051] The in Fig. 1 and Fig. The bearing device shown in Figure 2 comprises a bearing 10 provided with a first ring 12 and a second ring 14, which are able to rotate relative to each other about the axis X - X' of the bearing. In the exemplary embodiment shown, the first ring 12 is the inner ring of the bearing and the second ring 14 is the outer ring.

[0052] The bearing device is designed so that it does not conduct electrical currents. The bearing device has integrated electrical insulation.

[0053] The inner and outer rings 12 and 14 of the bearing are concentric and extend axially along the X-X' axis of the bearing. The inner and outer rings 12 and 14 are made of solid steel. The rings are of the solid type.

[0054] In the illustrated exemplary embodiment, the bearing 10 also includes a series of rolling elements 16, in this case balls, which are inserted radially between the inner and outer rings 12, 14. The rolling elements 16 are made of steel. The bearing 10 also includes a cage 17 for maintaining a uniform circumferential distance between the rolling elements 16. The bearing 10 may also be equipped with seals or sealing flanges.

[0055] The inner ring 12 comprises a cylindrical bore 12a, a cylindrical axial outer surface 12b radially opposite the bore, and two radially opposite end faces 12c, 12d axially delimiting the bore and the outer surface. The bore 12a and the outer surface 12b define the radial thickness of the inner ring 12. The bore 12a forms the inner surface of the inner ring. The first and second end faces 12c, 12d define the axial length of the inner ring 12.

[0056] The inner ring 12 further comprises an inner raceway 18 for the rolling elements 16, which is formed on the outer surface 12b. The raceway 18 is directed radially towards the outside.

[0057] The outer ring 14 comprises a cylindrical axial outer surface 14a, a cylindrical bore 14b radially opposite the outer surface 14a, and a first and a second radial end faces 14c, 14d axially delimiting the bore and the outer surface 14a. The outer surface 14a and the bore 14b delimit the radial thickness of the outer ring 14. The first and second end faces 14c, 14d delimit the axial length of the outer ring 14.

[0058] The outer ring 14 further comprises an outer raceway 20 for the rolling elements 16, which is formed on the bore 14b. The raceway 20 is directed radially inwards.

[0059] The bearing device also includes an electrically insulating sleeve 26, which is attached to the outer ring 14. The insulating sleeve 26 is attached to the outer surface 14a of the outer ring 14. The insulating sleeve 26 is attached to the outer ring 14.

[0060] The insulating sleeve 26 comprises a bushing 28 and an insulating insert 30, which is inserted radially between the outer ring 14 and the bushing 28. The insulating insert 30 is overmolded onto the outer ring 14 and the bushing 28.

[0061] The bushing 28 is annular in shape. The bushing 28 consists of two separate first and second parts 32 and 34. These two separate parts 32 and 34 form half-flanges, which in this case abut axially against each other. In the illustrated exemplary embodiment, the parts 32 and 34 of the bushing are identical and symmetrical relative to a radial median plane P of the device in order to reduce manufacturing costs. In this case, the radial median plane P passes through the center point of the rolling elements 16. Alternatively, it is of course also possible to provide non-symmetrical parts 32 and 34. In another variant, it could be possible to provide that the bushing 28 consists of more than two parts. Preferably, the parts 32 and 34 of the bushing 28 are made of steel. The parts 32 and 34 can advantageously be obtained from a sheet metal blank by cutting, punching, and rolling.Alternatively, parts 32, 34 can advantageously be obtained from a tube or from forged and / or rolled blanks, or also by sintering and stamping.

[0062] Each part 32, 34 of the bushing comprises an annular axial section 32a, 34a and an annular radial shoulder 32b, 34b that extends the axial section radially inward. The axial sections 32a, 34a are axially abutting one another. The radial shoulder 32b, 34b extends the end of the axial section 32a, 34a that is located axially on the outer side of the device. In the illustrated exemplary embodiment, the radial shoulders 32b, 34b are annular.

[0063] The bushing 28 comprises a cylindrical axial outer surface 28a and a cylindrical bore 28b, which is radially opposite the outer surface 28a and whose axis 25 is coaxial with the axis X - X'. The bore 28b forms the inner surface of the bushing 28. The bore 28b is radially oriented inwards, i.e., towards the side of the outer ring 14 and the insulating insert 30. The axial sections 32a, 34a of the bushing parts jointly define the outer surface 28a. Similarly, the axial sections 32a, 34a of the parts jointly define the bore 28b. The outer surface 28a and the bore 28b define the radial thickness of the bushing 28. The outer surface 28a of the bushing forms the outer surface of the bearing device 10. In other words, the outer surface 28a defines the outer diameter of the bearing device 10.

[0064] The radial shoulders 32b, 34b of the bushing parts extend radially beyond the outer surface 14a of the outer ring, i.e., they project radially inwards relative to the outer surface 14a. In other words, the free ends of the radial shoulders 32b, 34b are offset radially inwards from the outer surface 14a of the outer ring. The radial shoulders 32b, 34b extend to the vicinity of the bore 14b of the outer ring, remaining radially retracted from this bore 14b. The radial shoulders 32b, 34b remain axially spaced from the outer ring 14a.

[0065] Each radial shoulder 32b, 34b of the part 32, 34 of the bushing is provided with several through holes 36, 38, which are spaced apart relative to each other in the circumferential direction, in this case uniformly. Alternatively, the spacing of the holes 36, 38 could also be uneven.

[0066] In this case, holes 36 and 38 are identical to each other. Alternatively, holes 36 and 38 can be different. In the illustrated exemplary embodiment, holes 36 and 38 are circular. Alternatively, holes 36 and 38 can also have a different shape, for example, polygonal, rectangular, square, oval, etc.

[0067] As stated above, holes 36 and 38 are through holes. Holes 36 and 38 extend axially through the thickness of the associated radial shoulder 32b and 34b of part 32 of the bushing. Holes 36 and 38 open into the inner and outer surfaces of the associated shoulder 32b and 34b, respectively. The inner surface and the outer surface axially opposite the inner surface of each radial shoulder 32b and 34b define the axial thickness of the shoulder. For each radial shoulder 32b and 34b, the inner surface faces axially toward the inside of the device, and the outer surface faces axially toward the outside of the device.

[0068] In the illustrated exemplary embodiment, the holes 36 of the radial shoulder 32b of part 32 of the bushing are axially aligned with the holes 38 of the radial shoulder 34b of part 34. Alternatively, the holes 36 could be offset at an angle to the holes 38.

[0069] The bushing 28 also includes two opposing radial end faces 28c, 28d, which axially delimit the outer surface 28a. The end faces 28c, 28d define the axial length of the bushing. The end face 28c is delimited by the radial shoulder 32b, and the end face 28d is delimited by the radial shoulder 34b. More precisely, the end face 28c is delimited by the outer surface of the radial shoulder 32b, and the end face 28d is delimited by the outer surface of the radial shoulder 34b.

[0070] The end faces 14c, 28c of the outer ring and the bushing are located axially on a first side relative to the radial median plane P of the device, and the end faces 14d, 28d of the outer ring and the bushing are located axially on a second side relative to the radial median plane P, which is opposite the first side.

[0071] The end face 14c of the outer ring is axially offset towards the inside relative to the end face 28c of the bushing. The end face 14d of the outer ring is axially offset towards the inside relative to the end face 28d of the bushing. In other words, the end faces 14c, 14d of the outer ring are axially recessed relative to the end faces 28c, 28d of the bushing. The axial dimension of the outer ring 14 is smaller than the axial dimension of the bushing 28.

[0072] The end face 14c of the outer ring is axially offset towards the inside relative to the end face 12c of the inner ring. The end face 14d of the outer ring is axially offset towards the inside relative to the end face 12d of the inner ring.

[0073] The insulating insert 30 is made of electrically insulating material. The insulating insert 30 can be made, for example, of plastic such as PEEK or PA46, or of elastomeric material such as rubber.

[0074] The insulating insert 30 is inserted radially between the outer surface 14a of the outer ring and the bore 28b of the bushing. The insulating insert 30 covers the outer surface 14a of the outer ring. In this case, the insulating insert 30 completely covers the outer surface 14a of the outer ring when considering both the axial and circumferential directions. The insulating insert 30 also covers the end faces 14c and 14d of the outer ring.

[0075] The insulating insert 30 also covers the bore 28b of the bushing. In this case, the insulating insert 30 also completely covers the bore 28b when considering the axial and circumferential directions. The insulating insert 30 covers the bore of the axial section 32a, 34a of each part 32, 34 of the bushing.

[0076] The insulating insert 30 also covers the inner surface of the radial shoulder 32b, 34b of each part 32, 34 of the bushing. The insulating insert 30 also covers the free end of the radial shoulder 32b, 34b of each part 32, 34 of the bushing. The insulating insert 30 also covers the bore of the through holes 36, 38 of the radial shoulders 32b, 34b of the parts 32, 34 of the bushing.

[0077] The insulating insert 30 is annular in shape. The insulating insert 30 extends axially. The insulating insert 30 comprises a cylindrical axial outer surface 30a, a cylindrical bore 30b radially opposite the outer surface 30a, and a first and second opposing radial end faces 30c, 30d that axially delimit the bore and the outer surface. The radial end faces 30c, 30d axially delimit the insulating insert 30. The outer surface 30a and the bore 30b delimit the radial thickness of the insulating insert 30. The outer surface 30a is in radial contact with the bore 28b of the bushing. The bore 30b is in radial contact with the outer surface 14a of the outer ring and with the end faces 14c, 14d of the outer ring.

[0078] The insulating insert 30 comprises a group of blind holes 40, each extending axially within one of the through holes 36 of the radial shoulder 32b of the part 32 of the bushing. Each blind hole 40 extends axially from the end face 30c towards the outer ring 14, maintaining an axial distance from the end face 14c. In other words, each blind hole 40 has a bottom that is axially directed towards the outside and offset axially towards the outside relative to the end face 14c.

[0079] Each blind hole 40 corresponds to the positioning of an injection nozzle (not shown) that allows the insulating insert 30 to be overmolded during the manufacture of the bearing device. The shape of the blind hole 40 corresponds to the bearing surface of the associated injection nozzle. In this case, the blind holes 40 are identical to each other. Alternatively, the blind holes 40 may not be identical if the injection nozzles of the electrically insulating material of the insulating insert 30 have different shapes.

[0080] As stated above, in the illustrated exemplary embodiment, the insulating insert 30 covers the bore of the through holes 36 of the radial shoulder 32b of the bushing part 32. Thus, a bead of material is present radially between each blind hole 40 and the associated through hole 36 of the radial shoulder 32b. Alternatively, it might be possible to have no such bead of material if the injection nozzle is centered relative to the bore of the through hole 36 during the overmolding of the insulating insert 30.

[0081] In the exemplary embodiment shown, the number of blind holes 40 corresponds to the number of through holes 36 of the radial shoulder 32b of part 32 of the bushing.

[0082] Alternatively, the number of blind holes 40 could be less than the number of through holes 36, depending on the number of injectors.

[0083] The insulating insert 30 also includes a group of through holes 42, each extending axially within one of the through holes 38 of the radial shoulder 34b of the part 34 of the bushing. Each through hole 42 extends axially from the end face 30d towards the outer ring 14 and opens into the end face 14d.

[0084] Each through-hole 42 corresponds to the positioning of a pin (not shown) that enables the centering of part 34 of the bushing and the transmission of the clamping forces of the mold used during the manufacture of the bearing device. The shape of the through-hole 42 corresponds to the bearing surface of the associated pin. In this case, the through-holes 42 are identical to each other. Alternatively, the through-holes 42 may not be identical if the pins have different shapes.

[0085] As indicated above, in the illustrated exemplary embodiment, the insulating insert 30 covers the bore of the through holes 38 of the radial shoulder 34b of the bushing part 34. Thus, a bead of material is located radially between each through hole 42 and the associated through hole 38 of the radial shoulder 34b. Alternatively, it might be possible to have no such bead of material if the pin is centered relative to the bore of the through hole 38 during the overmolding of the insulating insert 30.

[0086] In the illustrated exemplary embodiment, the insulating insert 30, located between two circumferentially successive through holes 42, comprises a bolt 44 extending within the through holes 38 of the radial shoulder 34b of the part 34 of the bushing. The number of through holes 42 is therefore less than the number of through holes 38. Alternatively, the number of through holes 42 could also be equal to the number of through holes 38.

[0087] In the illustrated exemplary embodiment, the end face 14c of the outer ring is axially offset towards the inside relative to the end face 30c of the insulating insert. The end face 14d of the outer ring is axially offset towards the inside relative to the end face 30d of the insulating insert.

[0088] In the illustrated embodiment, the surfaces 30c, 28c and 30d, 28d of the insulating insert and the bushing are each coplanar. Alternatively, other arrangements are possible. For example, the bushing 28 could extend such that it cantilevers axially from the insulating insert 30 relative to the surfaces 30c and 30d, or it could remain axially retracted from these surfaces.

[0089] In the illustrated exemplary embodiment, the surfaces 12c, 28c and 12d, 28d of the inner ring and the bushing are each coplanar. Alternatively, other arrangements are possible. For example, the bushing 28 could extend such that it cantilevers axially relative to the surfaces 12c and 12d of the inner ring, or remain axially retracted from these surfaces.

[0090] The invention proceeds in the following manner to manufacture the bearing device.

[0091] In a first step, 50, which in Fig.As shown schematically in Figure 5, the second part 34 of the bushing is attached inside the mold, which is intended for overmolding the insulating insert 30. The mold bolts enable the centering of the second part 34.

[0092] In a second subsequent step 52, the outer ring 14 is placed inside the mold.

[0093] Then, in a third step 54, the first part 32 of the bushing is fixed inside the mold, bearing axially against the first part 32. In this position, fixed inside the mold, the first part 32 and the second part 34 of the bushing are radially spaced from the outer ring 14.

[0094] Then, in a fourth subsequent step 56, the insulating insert 30 is overmolded using injection nozzles of the mold located in the through holes 36 of the radial shoulder 32b of part 32 of the bushing. The insulating insert 30 is overmolded on both the outer ring 14 and on the first and second parts 32, 34 of the bushing 28.

[0095] In a fifth subsequent step 58, the unified arrangement formed from the outer ring 14, the first and second parts 32, 34, the bushing 28 and the insulating insert 30 is removed from the mold.

[0096] Then, in a sixth subsequent step 60, the end faces 28c, 28d of the bushing are ground. Taking into account the presence of the shoulders 32b and 34b of the bushing, the grinding process is carried out mainly on these and not on the insulating insert 30. During this step, the outer surface 28a of the bushing and the raceway 20 of the outer ring can also be ground.

[0097] Then, in a seventh step 62, the unified arrangement, which consists of the outer ring 14, the first and second parts 32, 34, the bushing 28 and the insulating insert 30, is assembled with the row of rolling elements 16, the cage 17 and the inner ring 12.

[0098] In the exemplary embodiments shown, the first ring 12 of the bearing is the inner ring and the second ring 14, on which the insulating insert 30 is overmolded, is the outer ring.

[0099] Alternatively, a reverse arrangement can be provided in which the second ring 14, onto which the insulating insert 30 is overmolded, is the inner ring. In this case, the insulating sleeve is located in the bore 12a of the inner ring. The insulating insert is thus inserted radially between the bore 12a of the inner ring and the outer surface of the bushing. The insulating insert is overmolded 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.

[0100] In the exemplary embodiments described, the bearing of the device is provided with a single row of rolling elements. In one variant, the bearing can be provided with multiple rows of rolling elements. Furthermore, the rolling bearing can comprise different types of rolling elements, for example, balls or rollers. In another variant, the bearing can be a plain bearing without rolling elements.

Claims

[1] Bearing device comprising a bearing (10) provided with a first ring (12) and a second ring (14) capable of rotating relative to each other, and an insulating sleeve (26) attached to the second ring (14) of the bearing, and provided with a bushing (28) and an insulating insert (30) inserted radially between the second ring (14) and the bushing (28) and made of electrically insulating material, wherein the bushing comprises an outer surface (28a) and an inner surface (28b) opposite the outer surface, which limit the radial thickness of the bushing, wherein the second ring (14) comprises an outer surface (14a) and an inner surface (14b) opposite the outer surface, which limit the radial thickness of the second ring, and a first and a second end face (14c, 14d) which limit the axial length of the second ring,wherein the insulating insert (30) is overmolded at least on one of the outer and inner surfaces of the second ring (14) of the bearing and at least on one of the outer and inner surfaces of the bushing (28), characterized by , that - the bushing (28) is made of at least two separate first and second parts (32, 34), each comprising an axial section (32a, 34a) and a radial shoulder (32b, 34b) extending the axial section radially towards the inside, wherein the axial sections (32a, 34a) of the first and second parts jointly at least partially bound the surface of the bushing (28) on which the insulating insert (30) is overmolded, - at least the radial shoulder (32b) of the first part of the bushing extends radially beyond the outer surface (14a) or inner surface of the second ring on which the insulating insert (30) is overmolded and is provided with several through holes (36) which are spaced apart relative to each other in the circumferential direction, - the insulating insert (30) is also overmolded on an inner surface of the radial shoulder (32b, 34b) of each of the first and second parts of the bushing and is at least partially overmolded on the first and second end faces (14c, 14d) of the second ring, and - the insulating insert (30) comprises a group of blind holes (40) which each extend axially within one of the through holes (36) of the radial shoulder (32) of the other first part of the bushing and remain axially at a distance from the first end face (14c) of the second ring. [2] Device according to claim 1, wherein the insulating insert (30) covers the bore of each hole of the multiple through holes (36) of the radial shoulder of the first part of the bushing. [3] Device according to claim 1 or 2, wherein the radial shoulder (34b) of the second part of the bushing extends radially beyond the outer surface (14a) or inner surface of the second ring on which the insulating insert is overmolded. [4] Device according to claim 3, wherein the radial shoulder (34b) of the second part of the bushing is provided with several through holes (38) which are spaced apart relative to each other in the circumferential direction, wherein the insulating insert (30) comprises a group of through holes (42), each of which extends axially within one of the through holes (38) and opens into the second end face (14d) of the second ring. [5] Device according to claim 4, wherein the insulating insert (30) covers the bore of each hole of the multiple through holes (38) of the radial shoulder (34b) of the second part of the bushing. [6] Device according to claim 4 or 5, wherein the insulating insert between two through holes (42) of the insulating insert, which are successive in the circumferential direction, comprises at least one bolt (44) which extends within one of the through holes (38) of the radial shoulder (34b) of the second part of the bushing. [7] Device according to one of the preceding claims, wherein the first and second part (32, 34) of the bushing are symmetrical relative to a radial median plane of the device. [8] Device according to one of the preceding claims, wherein the axial sections (32a, 32b) of the first and second part of the bushing are in axial contact with each other and together define the entire area of ​​the bushing (28) on which the insulating insert is overmolded. [9] A method for manufacturing a storage device according to any one of claims 1 to 8, comprising: - a step of attaching one of the first and second parts (32, 34) of the bushing to the bottom of a manufacturing mold, - a step of placing the second ring (14) within the manufacturing mold; - a step of fastening the other of the first and second part (32, 34) of the bushing within the manufacturing mold, - a step of placing injectors within the through holes (36) of the radial shoulder (32b) of the first part of the bushing, wherein the injectors remain axially at a distance from the first end face (14c) of the second ring, - a step of overmolding the insulating insert (30) using the injection nozzles, and - a step of assembly with the first ring (12) of the bearing of the arrangement which is formed from the second ring (14), the first and second part (32, 34) of the bushing and the insulating insert (30). [10] Electric motor comprising a housing, a shaft and at least one bearing device according to any one of claims 1 to 8, which is mounted radially between the housing and the shaft.

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