Modular magnetic axial bearing with removable winding

Abstract

[Modular magnetic axial bearing with removable winding] The modular magnetic axial bearing comprises a base 2 extending along a longitudinal axis XX' and having a blind housing 26, a coil arrangement, and an annular overmolded block 18 within which the coil arrangement is embedded and which is removably mounted in said housing 26. The modular magnetic axial bearing further comprises a cover 3 removably mounted on the base 2 so as to enclose said overmolded block 18 within said housing 26. Reference: Figure 8

Description

Title of the invention: Modular magnetic axial bearing with removable winding Technical field of the invention

[0001] The present invention relates to magnetic axial bearings, in particular intended to be connected to an industrial machine.

[0002] The present invention aims to constitute a magnetic axial bearing which includes a removable winding which can be disassembled in a non-destructive manner from the base, and this thanks to a new manufacturing process. Prior art

[0003] In known methods for manufacturing a magnetic axial bearing, the various components are placed one after the other in a bearing support, namely an electrically insulating part, then a pre-wired coil arrangement, before the assembly is overmolded directly into said bearing support.

[0004] In the event of an electrical fault due to an insulation fault among other things, there is no possible repair or touch-up, in particular of the coil circuit, due to the encapsulation of the elements during overmolding which implies that overmolding material, for example resin, gets everywhere in the bearing support.

[0005] In the event of a need for repair or replacement, only the bearing support is generally recoverable, but damaged, all other bearing components being destroyed.

[0006] Furthermore, during the manufacturing process, the wire-cable interconnection is achieved either by a brazed splice or by crimping a sleeve.

[0007] In both cases, this requires preparation of the wire and cable before making the connection and then insulating the latter.

[0008] All these manual operations are particularly time-consuming and can be improved.

[0009] Finally, the openings in the bearing must be sealed to prevent leaks of the overmolding material, which requires specific tooling and an additional step before assembling other mechanical elements. Summary of the invention

[0010] The invention aims to overcome at least some of the aforementioned drawbacks.

[0011] In light of the foregoing, the invention relates to a modular magnetic axial bearing comprising a base extending along a longitudinal axis and comprising a blind housing, a coil arrangement, an annular overmolded block within which the coil arrangement is embedded and which is removably mounted in said housing, said modular magnetic axial bearing further comprising a cover mounted in a removable manner on the base so as to enclose said overmolded block in said housing.

[0012] A modular magnetic axial bearing is thus produced in which the assembly of coils previously rolled and connected is overmolded in an overmolding mold having a shape identical to the bearing support which will then receive the overmolded block of coils, the different components being stacked in a removable manner in said bearing support.

[0013] The modular magnetic axial bearing may further include an electrically insulating part embedded in the overmolded block.

[0014] Preferably, the bearing further comprises means for removable closure of the cover on the base and an elastic assembly mounted in compression between the cover and the base or the overmolded block so as to push said cover along the longitudinal axis against said removable closure means.

[0015] For example, the elastic assembly comprises several elastic elements arranged circularly around the longitudinal axis.

[0016] Advantageously, the elastic elements comprise a material containing elastomer or metal.

[0017] According to one embodiment, at least one of the elastic elements has a ball shape, a toroidal shape, an annular shape, a continuous elongated shape open or closed on itself, a spring shape, or a corrugated blade shape.

[0018] In one embodiment, the overmolded block has at least one radial protrusion, and the base has a hollow in which said radial protrusion is engaged so as to block the arrangement of coils from rotating about the axis relative to said base.

[0019] Advantageously, the modular magnetic axial bearing further comprises a connector plate electrically connected to the coil arrangement and forming a projection relative to said coil arrangement, at least one connector plate being overmolded in the block overmolded at least partially in the radial protrusion.

[0020] The connection board may include one or more contactors or insulation displacement contacts.

[0021] The invention also relates to a method of manufacturing a modular magnetic axial bearing as described above, in which the coil arrangement is overmolded in an overmolding mold until an overmolded block incorporating said coil arrangement is formed, said overmolded block is placed in the housing of the base, said overmolded block is enclosed in the base by removably closing said base with the cover.

[0022] Preferably, in the process, the overmolding mold used comprises an en- casing forming a hollow in which the connector tray is engaged so as to block the arrangement of coils from rotating about the axis relative to said overmolding mold when the arrangement of coils is overmolded in the overmolding mold. Brief description of the figures

[0023] The invention will be better understood upon detailed study of an embodiment taken by way of non-limiting example and illustrated by the accompanying drawings, in which:

[0024] [Fig. 1] represents a first embodiment of the modular magnetic axial bearing according to the invention.

[0025] [Fig.2] represents the wired coil arrangement which is included in the axial bearing modular magnetic.

[0026] [Fig.3] represents the overmolding mold used to form the overmolding block from the wired coil arrangement during the manufacturing process of the modular magnetic axial bearing of [Fig.1], in the open position.

[0027] [Fig.4] represents the overmolding mold of [Fig.3], in the closed position.

[0028] [Fig.5] represents the underside of the overmolding cover illustrated by [Fig.3].

[0029] [Fig.6] represents the overmolded block produced by the overmolding step of the arrangement of reels.

[0030] [Fig.7] and [Fig.8] represent the base into which the overmolded block is inserted for the manufacture of the modular magnetic axial bearing.

[0031] [Fig.9] and [Fig. 10] represent the base into which the overmolded block is inserted for the manufacture of a modular magnetic axial bearing according to a second embodiment.

[0032] [Fig. 11] and [Fig. 12] represent the base into which the overmolded block is inserted for the manufacture of a modular magnetic axial bearing according to a third embodiment. Detailed description of the invention

[0033] The [Fig.1] illustration represents a first embodiment of the modular magnetic axial bearing 1 according to the invention.

[0034] The modular magnetic axial bearing 1 comprises a base 2 extending along a longitudinal axis XX' and having a blind cavity or housing 26 (visible in Figures 3, 8, 10 and 12).

[0035] The base 2 is provided with first and second opposing front faces 2a, 2b defining its thickness. The blind housing 26 extends axially from the first front face 2a. The bottom of the blind housing 26 remains axially distant from the first front face 2b.

[0036] The base 2 can be made of magnetic material.

[0037] The modular magnetic axial bearing 1 comprises an arrangement of coils 5 and an annular overmolded block 18.

[0038] The coil arrangement 5 is embedded in the overmolded block 18, which is illustrated in [Fig.6].

[0039] As illustrated in [Fig. 3], the arrangement of coils 5 is annular in shape and is configured to be integrated into an overmolding mold 11 during the manufacturing process of the modular magnetic axial bearing 1.

[0040] After the overmolding of the coil arrangement 5, a totally encapsulated, insulated block 18 is obtained, which allows its components to be held in position relative to each other so that they do not collide with each other, and which can be electrically tested in advance.

[0041] The modular magnetic axial bearing 1 further comprises a cover 3 mounted removably on the base 2 so as to enclose said overmolded block 18 in the housing 26.

[0042] In the mounted position of the cover 3 on the base 2, the overmolded block 18 is inaccessible from the outside.

[0043] The overmolding mold 11 has passages 15 through which the electrical cables 6 from the arrangement of coils 5 pass.

[0044] The modular magnetic axial bearing 1 includes a connection plate 7 electrically connected to the coil arrangement 5 and forming a projection relative to said coil arrangement 5.

[0045] Fig. 4 illustrates the overmolding mold 11 of Fig. 2, in the closed position by a disc 12 serving as a lid.

[0046] The disc 12 has specific shapes to close the overmolding mold 12, and may in particular have a projection 16 housed in a cavity 10, as illustrated by [Fig.4], which allows the cavity 10 to serve both to block the rotation of the disc 12 and the arrangement of coils 5.

[0047] As illustrated by [Fig.3], the modular magnetic axial bearing 1 has two connector trays 7 from which the cables 6 extend out of the overmolded block 18. Alternatively, it is possible to provide a single connector tray 7 or at least three connector trays 7.

[0048] Each connector tray 7 is overmolded into the overmolded block 18.

[0049] The overmolded block 18 further comprises at least one radial protrusion 20, here two protrusions 20.

[0050] Each connector tray 7 is then overmolded into the overmolded block 18 at least partially in one of the radial protrusions 20.

[0051] The base 2 has a recess in which each radial protrusion 20 is engaged so as to lock the arrangement of coils 5 relative to said base 2 when the overmolded block 18 is inserted into the housing 26 of the base 2.

[0052] Thus, thanks to the complementary anti-rotation shapes formed by the radial protrusion 20 and the associated hollow, when the overmolded block 18 is slid into the base 2, the fit of the base 2 is configured to provide small radial and angular clearances, allowing only the sliding of the overmolded block 18 along the longitudinal axis XX'.

[0053] The overmolded block 18 is inserted into the base 2 by adjusting the angular position of the connector trays 7 using the radial protrusions 20 opposite the hollows of the base, in particular by routing the cables 6 to the intended exit area.

[0054] The modular magnetic axial bearing 1 may further provide that the connection plate 7 includes an insulation displacement contact 8, or a plurality of insulation displacement contacts 8, which facilitate the interconnection operation of the cables 6 and / or the ends of the winding wires of the coils, allowing a simple, fast and secure electrical connection, and mechanically protected.

[0055] Thus, during the manufacturing process, the winding wires can advantageously be connected to the insulation displacement contacts 8 provided for this purpose.

[0056] Each insulation displacement contact 8 cannot accept wire with a diameter greater than one millimeter, so the number of coils can be doubled, and therefore also the number of insulation displacement contacts 8, to limit the current density in each coil and the connector.

[0057] The connection includes a step of crimping the cables onto the insulation displacement contacts 8 and then locking the crimped cables in the insulation displacement contacts 8, using retaining parts, for example, jumper parts provided for this purpose.

[0058] Other components can be added to the coil arrangement 5, such as a probe, in particular a temperature probe.

[0059] Once the coil arrangement 5 is enclosed in the housing 26 of the bearing support 2, the temperature probe makes it possible to know the temperature within the bearing 1 in order to prevent any overheating of the bearing 1, all the energy due to copper losses being stored in the housing after the closure of the latter by the cover 3.

[0060] Preferably, if the process relates to the manufacture of a modular magnetic axial bearing 1 comprising a connector plate 7 connected to the coil arrangement 5, the overmolding mold 11 used in this process comprises the cavity 10 forming a hollow in which the connector plate 7 is engaged so as to to lock in rotation about the axis XX' the arrangement of coils 5 relative to said overmolding mold 11 when the arrangement of coils 5 is overmolded in the overmolding mold 11 during said manufacturing process.

[0061] The disc 12, illustrated by Figures 4 and 5, may include extensions of the third passages 15 also allowing the cables 6 to pass through during the overmolding operation.

[0062] The disc 12 has an inlet 13 passing through said disc 12 and allowing a liquid overmolding material, for example a hot resin, for example comprising epoxy, to be poured into the overmolding mold 11 in which the coil arrangement 5 is located.

[0063] The disc 12 may have reliefs 17 allowing the creation of grooves 21 in the overmolded block, as illustrated by [Fig.6], which absorb the thermal expansion stresses of the overmolded block 18 during its use.

[0064] The use of the overmolding mold 11 makes it possible to avoid the overmolding step directly done in the base 2 in conventional processes.

[0065] The overmolding mold 11 includes passages 15 allowing the cables 6 from the overmolded block 18, more particularly from the coil arrangement 5, to pass through during the overmolding operation, to prevent them from being damaged and / or overmolded, since they are intended to connect the coil arrangement 5 to an industrial machine through the bearing support 2.

[0066] In the process, the overmolding mold 11 is covered by a disc 12 serving as a lid removably fixed to the overmolding mold 11 by removable closing means 14, such as screws.

[0067] Thus, the coil arrangement 5 is removably mounted in the housing 26, while being integrated into the overmolded block 18 which is itself also removable relative to the bearing body 2.

[0068] The modular magnetic axial bearing 1 may further include an electrically insulating part 25 which is placed in the housing 26 between the base 2 and the coil arrangement 5 before overmolding and which is embedded in the overmolded block 18.

[0069] This electrically insulating part 25 allows the overmolded block 18 to be electrically isolated directly before being placed in the housing 26 of the base 2.

[0070] The electrically insulating part is for example a sheet of insulating paper deposited on the inner diameter and the bottom of the housing of the base 2, and which has been overmolded so as to be integrated into the overmolded block 18.

[0071] The removability of the coil arrangement 5, more particularly of the overmolded block 18, relative to the bearing body 2, allows the overmolded block 18 to be removed for possible replacement of the coil arrangement 5, without having to destroy the assembly overmolded usually incorporating coils directly overmolded into a base, i.e. immovable in relation to it.

[0072] The removability of the coil arrangement 5, more particularly of the overmolded block 18, relative to the bearing body 2, also allows for a manufacturing process allowing non-destructive disassembly, therefore particularly advantageous, for the modular magnetic axial bearing 1 as described above, in which the coil arrangement 5 is overmolded in the overmolding mold 11 until an overmolded block 18 is formed incorporating said coil arrangement 5, said overmolded block 18 is placed in the base 2, said overmolded block 18 is enclosed in the base 2 by removably closing the base 2 with the cover 3.

[0073] This manufacturing process for the modular magnetic axial bearing 1 allows the entire arrangement of coils 5 and its overmolding to be prepared in advance, which allows for an overmolded block 18 to be already tested and ready for use in the manufacturing process.

[0074] In addition, the overmolded block 18 is modular because it can be mounted on different bearing supports 2 having a blind housing 26 of the same or similar dimensions.

[0075] The advantages of the modular magnetic axial bearing 1 and its manufacturing process are therefore economic, logistical and qualitative, the process integrating a pre-assembly step allowing certain manufacturing in advance to build up a stock, but also the manufacturing in a third location of the bearing support 2.

[0076] Furthermore, the encapsulation of the coil arrangement 5 in the overmolded block 18 being already done, the retention of this block in the base 2 is guaranteed by an adjunct mechanical locking and no longer by the adhesion of the overmolding resin, also reducing the risk of cracking and loss of material during operation of the modular magnetic axial bearing 1.

[0077] In addition, the overmolded block 18 stored is electrically tested, which makes it more reliable, and it is also replaceable once inserted removably into the bearing support 2.

[0078] The modular magnetic axial bearing 1 includes removable closing means 9 for the cover 3 on the base 2, such as screws, and an elastic assembly 24 mounted in compression between the cover 3 and the base 2 or the overmolded block 18 so as to push said cover 3 along the longitudinal axis XX' against said removable closing means 9.

[0079] The overmolded block 18 may further include cavities 19 intended to receive all or part of the elastic assembly 24.

[0080] The elastic assembly 24 may include several elastic elements in the cavities 19.

[0081] For example, the cavities 19 are arranged circularly around the longitudinal axis XX'.

[0082] Advantageously, the elastic elements 24 comprise a material comprising elastomer or metal.

[0083] For example, at least one of the elastic elements 24 has a ball shape, a toroidal shape, an annular shape, a continuous elongated shape open or closed on itself, a spring shape, or a corrugated blade shape.

[0084] The elastic elements 24 serve to create a preload on the overmolded block 18, ensuring mechanical support during the operation of the modular magnetic axial bearing 1, and contact on the metal to make the necessary heat exchange of each coil of the coil arrangement 5.

[0085] The use of elastic elements, in particular in circular shape around the longitudinal axis XX', so as to push the cover 3 uniformly relative to the overmolding block 18, makes it possible not to have to make the overmolding precisely to a height corresponding to the height from the bottom of the housing 26 to the cover 3, which is advantageous because this height is particularly difficult to obtain precisely and repeatedly, given the dimensional margins of the overmolding.

[0086] Thus, thanks to the elastic elements 24 positioned circularly, that is to say in a balanced manner around the longitudinal axis XX', the overmolded block 18 is pressed against the bottom of the housing 26 thanks to the distributed pressure of the elastic elements 24 against the cover 3 held by means of the removable closure means 9, arranged so that, when the cover 3 is added during the manufacturing process of the modular magnetic axial bearing 1, the elastic elements 24 put the overmolded block under stress at the bottom of the housing 26 and in an axial position centered around said longitudinal axis XX'.

[0087] According to the first embodiment of the modular magnetic axial bearing 1 illustrated by Figures 7 and 8, the elastic elements comprise elastomer and have a ball shape.

[0088] The choice of ball shape offers easier handling of the elastic elements 24, and in particular their positioning.

[0089] According to the second embodiment of the modular magnetic axial bearing 1 illustrated by Figures 9 and 10, the elastic elements comprise elastomer and have a toroidal shape, for example a washer shape.

[0090] According to the third embodiment of the modular magnetic axial bearing 1 illustrated by Figures 11 and 12, the elastic elements comprise metal and have a corrugated strip shape arranged around the longitudinal axis XX'.

[0091] As illustrated by Figures 7 to 12, all embodiments of the modular magnetic axial bearing 1 include a slot 23 which provides mechanical clearance.

[0092] Slot 23 cannot be added to the bearing support in prior art axial bearing module designs, in which the overmolding step is done directly in the bearing support, since the slot would constitute a leakage zone of the overmolding material which would prevent this overmolding from being carried out directly.

[0093] As illustrated by [Fig.8], [Fig. 10] and [Fig. 12], the modular magnetic axial bearing 1 may include a backup bearing 27 formed of a plurality of backup bearings and a plate 28 supporting said backup bearings arranged around the longitudinal axis XX', said backup bearings being redundancy elements intended to serve as replacements in case of failure of the other elements of the modular magnetic axial bearing 1.

Claims

Demands

1. Modular magnetic axial bearing (1) comprising a base (2) extending along a longitudinal axis (XX') and comprising a blind housing (26), a coil arrangement (5), an annular overmolded block (18) within which the coil arrangement (5) is embedded and which is removably mounted in said housing (26), said modular magnetic axial bearing (1) further comprising a cover (3) removably mounted on the base (2) so as to enclose said overmolded block (18) in said housing (26).

2. Modular magnetic axial bearing (1) according to claim 1, further comprising an electrically insulating part (25) embedded in the overmolded block (18).

3. Modular magnetic axial bearing (1) according to any one of claims 1 and 2, further comprising removable closing means (9) for the cover (3) on the base (2), and an elastic assembly (24) mounted in compression between the cover (3) and the base (2) or the overmolded block (18) so as to push said cover (3) along the longitudinal axis (XX') against said removable closing means (9).

4. Modular magnetic axial bearing (1) according to claim 3, wherein the elastic assembly (24) comprises several elastic elements arranged circularly around the longitudinal axis (XX').

5. Modular magnetic axial bearing (1) according to claim 4, wherein the elastic elements comprise a material comprising elastomer or metal.

6. Modular magnetic axial bearing (1) according to any one of claims 4 and 5, wherein at least one of the elastic elements has a ball shape, a toroidal shape, an annular shape, a continuous elongated shape open or closed on itself, a spring shape, or a corrugated blade shape.

7. Modular magnetic axial bearing (1) according to any one of claims 1 to 6, wherein the overmolded block (18) has at least one radial protrusion (20), and the base (2) has a hollow in which said protrusion (20) is engaged so as to lock in rotation about the axis (XX') the arrangement of coils (5) relative to said base (2).

8. Modular magnetic axial bearing (1) according to claim 7, further comprising a connector plate (7) electrically connected trically to the coil arrangement (5) and forming a projection relative to said coil arrangement (5), at least one connector tray (7) being overmolded into the overmolded block (18) at least partially into the radial protrusion (20).

9. Modular magnetic axial bearing (1) according to claim 8, wherein the connection tray (7) comprises at least one isolation displacement contactor (8).

10. 0 Method of manufacturing a modular magnetic axial bearing (1) according to any one of claims 1 to 9, wherein the coil arrangement (5) is overmolded in an overmolding mold (11) until an overmolded block (18) incorporating said coil arrangement (5) is formed, said overmolded block (18) is placed in the housing (26) of the base (2), said overmolded block (18) is enclosed in the base (2) by removably closing the base (2) with the cover (3).

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