Device for coupling two shafts, assembly comprising the device, and method for manufacturing the device

Abstract

The invention relates to a device (10) for coupling two shafts, the device comprising a first coupling half (12) capable of being connected to one shaft, a second coupling half (13) capable of being connected to another shaft, the first coupling half (12) and the second coupling half (13) being capable of being rotated together, the device (10) further comprising, in at least one of the coupling halves, a hub (18) rotatable about an axis of rotation (16), and a single ring (20) for coupling the hub to a shaft, the ring being electrically insulating. The invention also relates to an assembly comprising the device and to a method for manufacturing the device.

Description

[0001] Device for coupling two shafts, together with the device and method of manufacturing the device

[0002] Technical field

[0003] The present invention relates to a device for coupling two shafts, an assembly with the device and a method of manufacturing the device.

[0004] Prior art

[0005] Document EP3655674 describes a coupling composed of at least one half of the coupling on the input side and one half of the coupling on the output side. This document aims to make the shafts of these couplings electrically insulated from each other. The coupling comprises at least two hollow cylinders superimposed and integral with each other and arranged in the bore of one half of the coupling. The first cylinder is made of an electrically conductive material and the second cylinder is made of an electrically insulating material. Knurling is provided on the external and internal surfaces of the first cylinder as well as on the internal surface of the bore opposite the first cylinder. The knurling allowing a form connection between surfaces in contact, the knurling of the surfaces is provided in this document to ensure a material lock between the elements of the coupling.

[0006] To make the second cylinder, epoxy resin is injected between the first cylinder and the internal surface of the bore opposite the first cylinder. This causes concentricity problems between the first cylinder and the bore. The injection also risks creating unbalances if the epoxy has a mass that is not perfectly distributed around the first cylinder (possibly due to concentricity problems) leading to an imbalance during rotation of the coupling. In addition, the production of the second cylinder by injection requires the presence of the first cylinder to form an annular space with the bore. Furthermore, since the second epoxy cylinder is brittle, this coupling on the one hand requires the presence of the first steel ring to ensure the coupling with the shaft and on the other hand does not allow easy replacement of the second cylinder. This coupling is therefore complex, complex to produce and expensive.

[0007] There is a need for a coupling device and a manufacturing method that is simpler to implement, allowing the electrical isolation of the coupling halves from each other.

[0008] Statement of the invention

[0009] To this end, the invention provides a device for coupling two shafts, the device comprising a first coupling half capable of being connected to one shaft, a second coupling half capable of being connected to another shaft, the first and second coupling halves being capable of being driven in rotation together, the device further comprising, in at least one of the coupling halves, a hub rotatable about an axis of rotation, and a ring for coupling the hub to a shaft, the ring being electrically insulating. In particular, the device comprises a single ring for coupling the hub to a shaft, the ring being electrically insulating.

[0010] Alternatively, the ring is a torque limiter.

[0011] Alternatively, the hub has an internal surface with a roughness less than 0.8.

[0012] Alternatively, the roughness of the inner and outer surfaces of the ring is less than or equal to 3.2.

[0013] According to one variant, the ring has an outer surface, in contact with the hub, of cylindrical or conical shape.

[0014] Alternatively, the conical shape of the outer surface of the ring flares in one direction or the other along the axis of rotation.

[0015] According to one variant, the ring has an outer surface, in contact with the hub, of regular section, transversely to the axis of rotation.

[0016] According to one variant, the ring has an outer surface, in contact with the hub, of irregular section, transversely to the axis of rotation.

[0017] According to one variant, the ring has an outer surface, in contact with the hub, of ellipsoidal or polygonal section, transverse to the axis of rotation. According to one variant, the ring has a regular or stepped outer surface along the axis of rotation.

[0018] Alternatively, the ring has an inner surface parallel to the shaft surface.

[0019] According to a variant, the ring and / or the hub have a conformation limiting the relative displacement along the axis of rotation of the other of the ring or the hub.

[0020] According to one variant, the conformation of the ring and / or the hub comprises a shoulder transverse to the axis of rotation.

[0021] According to a variant, the conformation of the ring and / or the hub comprises a groove cooperating with the shoulder.

[0022] According to a variant, the device further comprises an electrically insulating plate, transverse to the axis of rotation, the plate and the ring defining an insulating housing for receiving a shaft.

[0023] According to a variant, the device further comprises a protection made of a material more rigid than the electrically insulating plate, the protection being on the face of the plate facing the outside of the housing.

[0024] According to one variant, the device is of the type a toothed coupling, a disc coupling, a diaphragm coupling, a universal joint, a rigid coupling, a hollow torsion shaft coupling.

[0025] According to a variant, the coupling between the ring and the hub is by friction.

[0026] Alternatively, the ring is obtained by machining from a solid bar or by machining from a tube or by casting.

[0027] Alternatively, the ring is in the coupling half driving the other coupling half to rotate.

[0028] Alternatively, the ring is made of a polymer such as a polyamide or a polyetheretherketone.

[0029] According to one variant, the hub has a bore in which the ring is shrunk.

[0030] The invention also relates to an assembly comprising the device as described above, a first shaft coupled to one of the hubs by the ring, a second shaft coupled to the other of the hubs. According to a variant, the ring is a torque limiter.

[0031] According to a variant, the ring is urged against the hub by the shaft.

[0032] According to a variant, the assembly further comprises an electrically insulating plate, transverse to the axis of rotation and fixed to the end of the shaft which is coupled to the hub by the ring.

[0033] According to a variant, the assembly further comprises protection made of a material more rigid than the electrically insulating plate.

[0034] According to a variant, a screw fixes the electrically insulating plate and the protection to the end of the shaft coupled to the hub by the ring, the screw having a head bearing against the protection.

[0035] According to a variant, the shafts are coupled by shrink fitting respectively in the ring and the hub.

[0036] The invention also relates to a method of manufacturing a coupling device as described above, comprising providing a first coupling half capable of being connected to a shaft, a second coupling half capable of being connected to another shaft, the first and second coupling halves being capable of being rotated together, providing an electrically insulating ring, assembling the ring in a hub of one of the two coupling halves. In particular, it involves providing a single ring for coupling the hub to a shaft, the ring being electrically insulating.

[0037] According to one variant, the ring is assembled to the hub by a shrink-fitting step.

[0038] Alternatively, the ring is obtained by machining from a solid bar or machining from a tube or by casting.

[0039] According to one variant, the internal surface of the hub in contact with the ring is obtained by machining, preferably by turning and / or by grinding.

[0040] According to a variant, the device is assembled to a shaft, the ring is urged against the hub by the shaft.

[0041] The use in this document of the verb "to understand", its variants, and its conjugations, cannot in any way exclude the presence of elements other than those mentioned. The use in this document of the indefinite article "un", "une", or of the definite article "le", "la" or "I'", to introduce an element does not exclude the presence of a plurality of these elements.

[0042] The terms "first", "second", etc. are used in this document exclusively to differentiate between different elements, without implying any order between these elements.

[0043] All of the preferred embodiments and all of the advantages of the coupling device according to the invention are transposed mutatis mutandis to the present assembly and manufacturing method - and vice versa. The different embodiments can be considered alone or in combination.

[0044] Brief description of the figures

[0045] Other characteristics and advantages of the present invention will appear on reading the detailed description which follows, for the understanding of which reference will be made to the appended figures which show:

[0046] - figure 1, a schematic view of an exemplary embodiment of the coupling device;

[0047] - figure 2, a schematic view of an exemplary embodiment of a detail of the coupling device of figure 1;

[0048] - figure 3, a schematic view of another exemplary embodiment of a detail of the coupling device of figure 1.

[0049] The drawings of the figures are not to scale. Like elements are generally denoted by like references in the figures. For the purposes of this document, identical or similar elements may bear the same references. Furthermore, the presence of reference numbers or letters in the drawings cannot be considered as limiting, including when these numbers or letters are indicated in the claims.

[0050] Detailed description of embodiments of the invention

[0051] The invention relates to a device for coupling two shafts, the device comprising a first coupling half capable of being connected to one shaft, and a second coupling half capable of being connected to another shaft. The first and second coupling halves are capable of being driven in rotation together. The device further comprises, in at least one of the coupling halves, a hub movable in rotation about an axis of rotation and a ring for coupling the hub to a shaft, the ring being electrically insulating. The advantage of the device is that it allows the coupling halves to be electrically insulated from each other thanks to the ring made of insulating material. Furthermore, since the ring ensures the coupling of the hub to the shaft, the device is simple and easy to manufacture.

[0052] Figure 1 illustrates a schematic view of an exemplary embodiment of the coupling device 10. The device 10 can be mounted in a drive kinematic chain, such as in a vehicle (of the car, coach, train type) or in a rolling mill. The device 10 is of the toothed coupling, disc coupling, diaphragm coupling, universal joint, rigid coupling, or hollow torsion shaft coupling type. Thus, the invention is suitable for a wide variety of coupling devices.

[0053] The device 10 allows the coupling of two shafts 8 and 9. The device allows the transmission of the rotational movement around an axis of rotation 16 from one of the shafts (the input shaft), to the other shaft (the output shaft); for example, the shaft 8 can be the driving shaft, or input shaft, and the shaft 9 can be the driven shaft, or output shaft. The shafts are rotatable around the axis of rotation 16, which can be substantially common to both shafts. An angle between the axes of rotation of the shafts can be envisaged. The driving shaft is rotated by a drive machine (motor, gearbox, reducer, etc.). The device 10 allows an axial offset of the shafts 8 and 9. The device also allows a radial and angular offset of the shafts or an angular offset of the shafts. Thus, the device 10 adapts to a wide variety of couplings.

[0054] The device 10 comprises a first coupling half 12 adapted to be connected to one of the shafts - such as shaft 8 - and a second coupling half 13 adapted to be connected to the other shaft - such as shaft 9. According to Figure 1, the shafts are connected, coupled to each half 12, 13, along their respective axis of rotation 16, 17. The axes of rotation 16, 17 are shown coaxial in Figure 1 but may also not be (and be radially or angularly offset as mentioned previously). More specifically, one shaft end is connected, coupled to each half 12, 13. The first 12 and second 13 coupling halves are adapted to be rotated together. This allows the transmission of the rotational speed and torque from the shaft of one coupling half to the shaft of the other coupling half.For example, the (first) coupling half 12 is the driving part of the device 10 (or input part), connected to the input shaft 8, and the (second) coupling half 13 is the driven part of the device 10 (or output part), connected to the output shaft 9. In other words, the driving motion of the shaft coupled to the coupling half 12 is transmitted to the shaft coupled to the coupling half 13. Conversely, the (second) half 13 can be the driving part and the (first) half 12 can be the driven part; thus one or the other of the coupling halves is the driving part and the other of the coupling halves is the driven part.

[0055] In each of the coupling halves 12, 13, the device 10 may further comprise a hub 18, 19, rotatable about its own axis of rotation, respectively 16 and 17 (the axes may or may not be coaxial). Depending on the coupling half on which the hubs 18, 19 are located, the hub allows the transmission of the rotational movement of the drive shaft to the other coupling half or allows the transmission of the rotational movement from the other coupling half to the driven shaft. According to Figure 1, one or other of the coupling halves 12, 13 may be the driving part (corresponding to the input of the coupling device) or the driven part (corresponding to the output of the drive device). Subsequently, and by way of example to simplify the present description, the coupling half 12 is the driving part and the coupling half 13 is the driven part.

[0056] The device 10 may further comprise one or more sleeves 24, 25 in the coupling halves 12, 13, respectively. A sleeve 24, 25 for each half 12, 13 is shown as an example in the figures, and for the example of a toothed coupling given as an example in the figures. The sleeves 24, 25 are fixed to each other or be made of a single piece, and be rotated about a common axis of rotation or about its own axis of rotation respectively. The sleeve 24 is rotated by a toothing 26 by the hub 18. The sleeve 24 rotated by the hub 18 in turn drives the sleeve 25 of the coupling half 13. The sleeve 25 then drives the hub 19 by a toothing 27. For a disc coupling, the drive of the sleeves 24 and 25 is carried out by means of the disc sets. The sleeve 24 can be driven in rotation by a flexible connection (toothing, disc sets, diaphragm, etc.)) or rigid (hollow torsion shaft or rigid coupling) with the hub 18. ... The sleeve 25 then drives the hub.

[0057] 19 by a flexible connection (teeth, disc set, diaphragm) or rigid.

[0058] The device 10 may also comprise covers 28, 29 in the coupling halves 12, 13, respectively. The covers 28, 29 are fixed on the sleeves 24, 25, respectively. The sleeves 24, 25 and the covers 28, 29 make it possible to isolate the teeth 26, 27 from the environment, in particular dust.

[0059] The device 10 further comprises a ring 20 for coupling a hub to a shaft. The ring 20 couples a shaft to a hub within one or other of the coupling halves 12, 13. The ring 20 directly couples the shaft to the hub within one or other of the coupling halves 12, 13. As an example in Figure 1, the ring 20 couples the hub 18 to the shaft 8 within the coupling half 12 driving the other coupling half 13 in rotation. The ring 20 may thus be in the driving part of the device 10 - but may be in the driven part, coupling the hub 19 to the shaft 9.

[0060] The ring 20 connects the hub 18 to the shaft 8. The ring 20 connects the hub 18 directly to the shaft 8. The ring 20 is in contact with the hub 18 and the shaft 8. The ring 20 is in contact directly with the hub 18 and directly with the shaft 8. The outer surface and the inner surface of the ring

[0061] 20 are in contact with the hub 18 and the shaft 8 respectively. The outer surface and the inner surface of the ring 20 are respectively in contact directly with the hub 18 and directly with the shaft 8. The ring 20 allows the transmission of torque between the shaft 8 and the hub 18 (in one direction as in the other, depending on the coupling half concerned). The ring 20 allows the transmission of torque directly between the shaft 8 and the hub 18 (in one direction as in the other, depending on the coupling half concerned). The ring 20 transmits the power between the shaft 8 and the hub 18. The ring 20 transmits the power directly between the shaft 8 and the hub 18. There is therefore no loss of power. The device 10 comprises only one coupling part, the ring 20, between the hub 18 and the shaft 8. The ring 20 is a single coupling ring between the hub and a shaft, made of insulating material. The ring 20 is a single ring between the hub 18 and the shaft 8.The ring 20 is a single intermediate ring between the hub 18 and the shaft 8. In other words, the ring 20 directly couples the hub 18 to the shaft 8. There are no parts other than the ring 20 between the hub 18 and the shaft 8 to allow the transmission of torque. The ring 20 allows concentricity during the assembly of the device 10, which facilitates the assembly of the device 10. This simplifies the assembly of the device 10 and makes the device simpler and less expensive. Only one part is mounted and adjusted in position between the shaft 8 and the hub 18. Furthermore, the ring 20 can easily be replaced in the event of wear.

[0062] The ring 20 is electrically insulating. This makes it possible to electrically isolate the two shafts through the two coupling halves 12, 13. This makes it possible to interrupt the electrical contact along a kinematic chain in which the device 10 is assembled. The use of the electrically insulating ring 20 makes it possible to simply isolate the shafts 8 and 9 from each other through the device 10. The use of a single ring (or single ring) between the hub 18 and the shaft 8 makes it possible to reduce the costs for carrying out the coupling and ensuring electrical insulation, compared to the solutions of the prior art (in particular the document EP3655674 which involves two additional cylinders).

[0063] The ring 20 is a ring-shaped part before manufacturing the device. The ring 20 is provided in the form of a ring. The ring 20 is a part that has its own structure, in the form of a ring. The ring 20 has its own structure in the form of a ring regardless of its position in the device. The ring 20 is assembled in the form of a ring in the hub of one of the two coupling halves. The ring 20 is present in the form of a ring in the hub of one of the two coupling halves. The shape of the ring 20 is not obtained by pressing or injection into the device. Thus, the ring 20 can be replaced, in the event of wear for example, in a simple manner. Also, the device 10 can be provided with the ring 20 present in the hub, regardless of the mounting on the shafts.

[0064] The material of the ring 20 is chosen so as to be electrically insulating. Also, the ring ensuring the coupling between the ring 20 and the shaft, the material of the ring is chosen to withstand high loads, axially and radially and pressure (which is not the case in the document EP3655674 where the second cylinder could be brittle). The material of the ring 20 also makes it possible to resist the aggressiveness of the environment, in particular dust. The material of the ring 20 is also chosen to facilitate its manufacture. The material is for example a polymer, for example a polyamide or a polyetheretherketone.

[0065] The ring may be a torque limiter. This makes it possible to absorb a torque difference between the drive part and the driven part. For example, during a momentary blockage of an element of the kinematic chain such as the blocking of a wheel of a train or a failure to introduce a slab into a rolling mill, the driven coupling half of the device is slowed down by a braking torque, but not the driving coupling half. The device 10 makes it possible to absorb an overtorque of the driving part, which manifests itself by braking of the driven part without damaging the driving part or the drive motor. This cannot be obtained in the devices of the prior art. In particular, this cannot be obtained when deep texturizing of the contacting parts is carried out, for example by knurling, in order to increase the grip between the rotating parts.In particular, this cannot be achieved by the coupling of document EP3655674 where the presence of knurling on the inner surface of the bore of the second clutch half and the presence of knurling on the outer surface of the first cylinder ensures anchoring of the material of the second cylinder. This anchoring blocks the materials in contact and therefore prevents torque limitation - in particular by sliding. In particular, the injection of epoxy to form the second cylinder constitutes a rigid contact with the knurling of the first cylinder and a rigid contact with the knurling on the inner surface of the bore of the second clutch half and therefore prevents torque limitation.

[0066] The coupling between the ring 20 and the hub (18 for example) is by friction. The ring 20 can rotate freely in the hub 18, braked only by the friction resulting from the pressure constraints existing between the hub 18 and the ring 20. The mounting of the shaft 8 allows the ring 20 to be stressed against the hub 18. The force-fitting of the shaft 8 in the ring 20 puts the ring 20 under pressure against the hub 18. This allows the friction coupling, while ensuring possible sliding to limit the torque. The pressure between the shaft 8, the hub 18 and the ring 20 is adjusted so that the friction torque (or force) is at a certain threshold. When the braking torque exceeds this threshold, then the friction torque is lower than the braking torque and sliding between the shaft 8 and the hub 18 occurs, via the ring 20.As the braking torque reduces and becomes lower than the threshold, the friction torque becomes greater than the braking torque and slippage ceases between the shaft 8 and the hub 18, via the ring 20; the driving half again drives the driven half. The material of the ring 20 is chosen so as to transmit the torque between the shaft and the hub by friction.

[0067] The torque limitation is by sliding between the shaft 8 and the hub 18, via the ring 20. It is preferable that the sliding limiting the torque occurs at the interface between the ring and the hub rather than between the ring and the shaft so as not to alter the surface condition of the shaft (which is more complex and expensive to replace than the hub).

[0068] The roughness of the inner and outer surfaces of the ring 20 may be less than or equal to 3.2 (corresponding to an arithmetic mean deviation of the profile Ra along the ring. The unit is pm.). Such roughness allows frictional driving of the hub 18 by the shaft 8 via the ring 20, while ensuring sliding between the shaft 8 and the hub 18, via the ring 20 if a braking overtorque occurs in the kinematic chain. Such roughness ensures sliding between the shaft 8 and the hub 18, via the ring 20 if a braking overtorque occurs on the other coupling half 13 without damaging the surfaces of the ring 20. Such roughness also makes it possible to avoid damaging the ring 20 during the manufacture (or assembly) of the device, by assembling the ring 20. A roughness of a surface less than or equal to 3.2 corresponds to a smooth surface.Other higher roughness values ​​may also be suitable.

[0069] The hub coupled to the shaft via the ring 20, for example the hub 18 in Figure 1 on the coupling half 12 corresponding to the driving part, may have an internal surface with a roughness less than 0.8 (corresponding to an arithmetic mean deviation of the profile Ra. The unit is pm.). The internal surface of the hub 18 corresponds to the surface of the bore 22. Such roughness allows frictional driving of the hub 18 by the shaft via the ring 20, while ensuring sliding between the shaft 8 and the hub 18, via the ring 20 if a braking overtorque occurs on the other coupling half 13. Such roughness ensures sliding between the shaft 8 and the hub 18, via the ring 20 if a braking overtorque occurs on the other coupling half 13 without damaging the surfaces of the ring 20.Such roughness also makes it possible to avoid damaging the ring 20 during the manufacture (or assembly) of the device, by assembling the ring 20. A roughness of a surface less than 0.8 corresponds to a smooth surface. Other higher roughness values ​​may also be suitable.

[0070] The ring 20 may be assembled and held in position in the coupling half by shrink-fitting. The hub 18 has a bore 22 into which the ring 20 is shrink-fitted. The ring 20 is held in position in the device 10 by an interference fit. The outer surface of the ring 20 is against the inner surface of the bore 22. The ring 20 may have an outer surface in contact with the hub 18 of cylindrical shape. Thus, along the axis of rotation 16, the outer surface is regular, of constant diameter. This makes it possible to manufacture the ring and assemble it to the device 10 easily. Alternatively, the ring 20 may have an outer surface in contact with the hub 18 of conical shape. The conical shape of the outer surface of the ring 20 may flare in one direction or the other along the axis of rotation 16.For example, the conical shape may flare in the direction of insertion of the shaft 8 into the ring 20; in Figure 1, and by way of example, the outer surface of the ring may flare from left to right. This makes it possible to prevent the hub 18 from moving towards the inside of the device 10. Conversely, the conical shape may flare in the opposite direction to the direction of insertion of the shaft 8 into the ring 20; in Figure 1, and by way of example, the outer surface of the ring may flare from right to left. This makes it possible to prevent the hub 18 from moving towards the outside of the device 10. In both cases of conicity of the outer surface of the ring 20, the bore 22 of the hub 18 is also conical, of a shape complementary to that of the ring 20.

[0071] The outer surface of the ring may be smooth or stepped along the axis of rotation 16. Thus, a smooth surface facilitates the manufacture of the ring 20. A stepped surface allows for easier insertion of the ring 20 into the hub. A stepped surface also allows for more effective retention of the ring 20 in the hub 18, axially in one direction.

[0072] Alternatively or in combination, the outer surface of the ring may have various cross-sectional shapes, transverse to the axis of rotation 16. The ring 20 may have the outer surface, in contact with the hub 18, of regular or irregular cross-section transverse to the axis 16. The irregular cross-section is, for example, ellipsoidal. This allows for better transmission of the torque from the ring 20 to the hub 18 or vice versa (for the driven half). The irregular cross-section is, for example, polygonal. This allows for transmission of the torque by mechanical locking. The advantage is that this allows for good transmission of the torque between the shaft and the ring while limiting friction; this makes it possible to limit the stress on the ring by the shaft, and therefore the stresses in the ring. The regular cross-section is, for example, circular.A regular section allows easy manufacture of the ring 20 and an irregular section allows torque transmission without using a friction force.

[0073] The ring 20 may have an inner surface, in contact with and parallel to the surface of the shaft. The ring 20 may also have a conical inner surface, widening from the inside to the outside, of a shape complementary to that of the end of the shaft in the ring 20.

[0074] The ring 20 can be obtained by machining from a solid bar. This allows for greater freedom in the shape and size of the ring. Alternatively, the ring 20 can be obtained by machining from a tube. This allows for faster manufacturing of the ring, with less material loss. Alternatively, the ring 20 can be obtained by molding - in particular by thermoforming or injection molding. This allows for consistency in the shape and dimensions of the ring and also allows for great freedom in the shape of the ring. In addition, molding allows the fibers of the molded material to be oriented transversely to the axis of the ring 20, allowing the ring to better withstand expansion. Regardless of how the ring 20 is obtained, this part has its own ring structure. The ring 20 has its own ring-shaped structure - and independently of its presence in the device.

[0075] The internal surface of the hub 18 of the coupling half 12 can be obtained by machining (or mechanical machining), preferably by turning and / or by grinding. This makes it possible to manufacture the hub with low machining tolerances. The machining is carried out so as to obtain a surface condition of the hub 18 with a roughness as indicated previously. The hub 19 could have a different shape from that shown in Figure 1. In Figure 1, there is a symmetry between the two halves. This symmetry facilitates the management of the parts because it makes it possible to mount a coupling half on any type of shaft. It is nevertheless possible to have a different shaft / hub interface between the half 12 and the half 13. The machining of the hub 19 of the part 13 will then be adapted to obtain the desired interface. The device 10 may comprise an electrically insulating plate 30, transverse to the axis of rotation 16.The plate 30 and the ring 20 define an insulating housing for receiving the shaft. The plate 30 is at the end of the shaft coupled to the ring 20. The periphery of the plate 30 may be in contact with the ring 20, and the hub 18. Thus, the ring 20 and the plate 30 make it possible to electrically insulate the drive shaft (or the driven shaft, depending on the configuration of the device). The material of the plate 30 may be the same as the material of the ring 20 - with the same characteristics and advantages. The plate 30 makes it possible in particular to block the hub 18 in translation towards the inside of the device 10, in particular when the ring 18 has a conical shape, widening outwards.

[0076] The device 10 may also comprise a protection 32 made of a material that is more rigid than the electrically insulating plate 30. The protection 32 makes it possible to protect the plate 30. In particular, the protection 32 is on the face of the plate 30 opposite the shaft. The protection 32 is outside the housing defined by the ring 20 and the plate 30. The assembly of the plate 30 and the protection 32 forms a safety plate. The plate 30 and the protection 32 may be fixed to the end of the shaft coupled to the hub 18 by the ring 20. In particular, a fixing member such as a screw 34 ensures the fixing of the plate 30 and the protection 32 to the shaft. In the event of using a fixing screw 34, the head of the screw bears against the protection 32. The protection 32 thus prevents deformation of the electrically insulating plate 30 due to the member for fixing to the shaft. The protection 32 is for example made of steel.

[0077] Figures 2 and 3 are schematic views of exemplary embodiments of a detail of the coupling device 10 of Figure 1. In particular, in the device 10 of Figures 2 and 3, the ring 20 and / or the hub 18 have a conformation limiting the relative displacement along the axis of rotation 16 of the other of the ring 20 or the hub 18. The conformation hinders the relative displacement of the two parts. The conformation of the ring 20 and / or the hub 18 extends transversely to the axis 16. The conformation allows the anchoring of the two parts along the axis of rotation 16. The ring 20 and the hub 18 have a reduced, limited, or even zero relative displacement. The conformation of the ring 20 and / or the hub 18 may comprise a shoulder 36, 38, 40 transverse to the axis of rotation 16. The shoulder forms a crown hindering the relative movement of the parts.The conformation of the ring 20 and / or the hub 18 may also comprise a groove 42, 44, 46 cooperating with the shoulder 36, 38, 40 to limit, or even block, the relative movement of the ring 20 and the hub 18 along the axis 16.

[0078] According to Figure 2, the ring 20 has the shoulder 36 at one end along the axis of rotation 16 and the groove 42 at the other end. The hub 18 has the groove 44 cooperating with the shoulder 36 of the ring 20 and the shoulder 38 cooperating with the groove 42 of the ring. The shoulder 36 extending radially outward in the groove 44 limits the movement of the ring 20 towards the inside of the device 10; the shoulder 38 extending radially inward in the groove 42 limits movement of the ring 20 towards the outside of the device 10. Thus, the relative movement of the ring 20 and the hub 18 is limited or even blocked along the axis of rotation 16.

[0079] According to Figure 3, the ring 20 or the hub 18 has the shoulder 40 between the ends of the ring 20. The shoulder 40 cooperates with the groove 46 on the other part. For example, the ring 20 has the shoulder 40 between its ends cooperating with the groove 46 on the hub 18. The shoulder 40 can form a clip in the groove 46. The shoulder 40 extending radially outward in the groove 46 limits the movement of the ring 20 in both directions along the axis of rotation 16. Thus, the relative movement of the ring 20 and the hub 18 is limited or even blocked along the axis of rotation 16.

[0080] The invention also relates to an assembly comprising the device 10, a first shaft (such as the shaft 8) coupled to one of the hubs by the ring 20 (such as the hub 18), and a second shaft coupled to the other of the hubs such as the hub 19). All the characteristics and advantages previously described apply to the assembly and vice versa.

[0081] The invention also relates to a method of manufacturing (or assembling) a device 10 and the assembly comprising the device 10. The method comprises providing a first coupling half (such as half 12) capable of being connected to a shaft (8 for example), a second coupling half (such as half 13) capable of being connected to another shaft (9 for example). The first and second coupling halves are capable of being rotated together. The method also comprises providing the electrically insulating ring 20. The ring 20 is a ring-shaped part before manufacturing the device. The ring 20 is provided in the form of a ring. The ring 20 is provided with its own structure in the form of a ring. The shape of the ring 20 is not obtained by pressing or injection into the device. The ring 20 can be replaced, in the event of wear for example, in a simple manner.The method then comprises assembling the ring in a hub (e.g. hub 18) of one of the two coupling halves (e.g. half 12). The ring 20 is assembled as a ring in the hub of one of the two coupling halves, during the manufacture of the device 10. The ring 20 can be assembled to the hub, independently of the connection of the device to the shafts. In the method, a single electrically insulating and coupling ring 20 between the hub and a shaft is provided and assembled to form the device. Furthermore, the ring 20 does not undergo any deterioration during assembly to the hub. The ring 20 can be assembled freely in the hub, or even without physical contact between the ring and the hub. The ring can be completely free in rotation and axially before assembly on the shaft 8.It is only once the mounting or assembly to the shaft 8 (of a machine) has been carried out that there is contact between the surfaces and a frictional connection between the ring and the hub. The ring 20 can be urged against the hub 18 by inserting the shaft 8 into the ring 20. The shaft 8 is introduced into the ring 20 (directly) in contact with the inner surface of the ring 20. The ring 20 is in contact with the shaft 8 and with the hub 18. The ring 20 is in contact directly with the shaft 8 and directly with the hub 18. The ring 20 can also be assembled to the hub 18 by a shrink-fitting step. The ring can be obtained by machining from a solid bar or machining from a tube or by molding (for example by thermoforming or by injection). Whatever the method of obtaining the ring 20, this part has a specific ring structure. The ring 20 has its own ring-shaped structure - and independently of its presence in the device.The internal surface of the hub 18 in contact with the ring 20 can be obtained by machining, preferably by turning and / or by grinding. All the characteristics and advantages previously described apply to the method. The present invention has been described in relation to specific embodiments, which have a purely illustrative value and should not be considered as limiting. In general, it will be obvious to a person skilled in the art that the present invention is not limited to the examples illustrated and / or described above. For example, it is conceivable that the ring 20 provides the electrical insulation function within the device, or the torque limiter function between the shaft and the hub, or both the electrical insulation and torque limiter functions between the shaft and the hub.

Claims

Demands 1. Device (10) for coupling two shafts, the device comprising • a first half (12) of coupling suitable for being connected to a tree, • a second coupling half (13) adapted to be connected to another shaft, the first (12) and second coupling halves (13) being adapted to be driven in rotation together, the device (10) further comprising, in at least one of the coupling halves, • a hub (18) that can rotate about an axis of rotation (16), • a single coupling ring (20) of the hub to a shaft, the ring being electrically insulating.

2. Device according to claim 1, wherein the ring is a torque limiter.

3. Device according to any one of the preceding claims, wherein the hub (18) has an internal surface with a roughness of less than 0.

8.

4. Device according to any one of the preceding claims, wherein the roughness of the inner and outer surfaces of the ring (20) is less than or equal to 3.

2.

5. Device according to any one of the preceding claims, in which the ring (20) has an outer surface, in contact with the hub (18), of cylindrical or conical shape.

6. Device according to the preceding claim, in which the conical shape of the outer surface of the ring (20) flares out in one direction or the other along the axis of rotation (16).

7. Device according to any one of the preceding claims, wherein the ring (20) has an outer surface, in contact with the hub (18), of regular section, transverse to the axis of rotation (16).

8. Device according to any one of claims 1 to 6, wherein the ring (20) has an outer surface, in contact with the hub (18), of irregular section, transverse to the axis of rotation (16).

9. Device according to any one of the preceding claims, wherein the ring (20) has an outer surface, in contact with the hub (18), of ellipsoidal or polygonal cross-section, transverse to the axis of rotation (16).

10. Device according to any one of the preceding claims, wherein the ring (20) has a regular or stepped outer surface along the axis of rotation (16).

11. Device according to any one of the preceding claims, wherein the ring (20) has an inner surface parallel to the surface of the shaft (8).

12. Device according to any one of the preceding claims, wherein the ring (20) and / or the hub (18) have a conformation limiting the relative displacement along the axis of rotation (16) of the other of the ring (20) or of the hub (18).

13. Device according to the preceding claim, wherein the conformation of the ring (20) and / or the hub (18) has a shoulder (36, 38, 40) transverse to the axis of rotation (16). A device according to the preceding claim, wherein the conformation of the ring (20) and / or the hub (18) comprises a groove (42, 44, 46) cooperating with the shoulder (36, 38, 40). A device according to any one of the preceding claims, further comprising an electrically insulating plate (30) transverse to the axis of rotation, the plate (30) and the ring (20) defining an insulating housing for receiving a shaft. A device according to the preceding claim, further comprising a guard (32) made of a material more rigid than the electrically insulating plate (30), the guard (32) being on the face of the plate (30) facing outwards from the housing. A device according to any one of the preceding claims, which is of the type a toothed coupling, a disc coupling, a diaphragm coupling, a universal joint, a rigid coupling, or a hollow torsion shaft coupling.A device according to any one of the preceding claims, wherein the coupling between the ring (20) and the hub (18) is achieved by friction. A device according to any one of the preceding claims, wherein the ring (20) is obtained by machining from a solid bar, by machining from a tube, or by molding. A device according to any one of the preceding claims, wherein the ring (20) is in the coupling half (12) which drives the other coupling half (13) in rotation. A device according to any one of the preceding claims, wherein the ring (20) is made of a polymer such as a polyamide or a polyetheretherketone. A device according to any one of the preceding claims, wherein the hub has a bore (22) in which the ring (20) is press-fitted. An assembly comprising • the device (10) according to one of the preceding claims, • a first shaft (8) coupled to one (18) of the hubs by the ring (20), • a second shaft (9) coupled to the other of the hubs (19). Assembly according to the preceding claim, wherein the ring (20) is a torque limiter. Assembly according to claim 23 or 24, wherein the ring (20) is forced against the hub (18) by the shaft (8). Assembly according to any one of claims 23 to 25, further comprising an electrically insulating plate (30), transverse to the axis of rotation and fixed to the end of the shaft that is coupled to the hub (18) by the ring (20). Assembly according to claim 26, further comprising a guard (32) made of a material more rigid than the electrically insulating plate. Assembly according to claim 27, wherein a screw (34) fixes the electrically insulating plate (30) and the protection (32) to the end of the shaft coupled to the hub (18) by the ring (20), the screw (34) having a head bearing against the protection (32).

29. Assembly according to any one of claims 23 to 28, wherein the shafts (8, 9) are coupled by shrink fitting respectively in the ring (20) and the hub (19).

30. A method for manufacturing a coupling device (10) according to any one of claims 1 to 22, comprising • the supply of a first half (12) of a coupling suitable for connection to one shaft, and a second half (13) of a coupling suitable for connection to another shaft, the first and second halves of the coupling being suitable for being driven in rotation together, • the supply of a single coupling ring (20) for the hub to a shaft, the ring being electrically insulating, • the assembly of the ring (20) in a hub (18) of one of the two coupling halves.

31. Method according to the preceding claim, wherein the ring (20) is assembled to the hub by a shrink-fitting step.

32. A method according to any one of claims 30 or 31, wherein the ring (20) is obtained by machining from a solid bar or machining from a tube or by molding.

33. Method according to any one of claims 30 to 32, wherein the internal surface of the hub (18) in contact with the ring (20) is obtained by machining, preferably by turning and / or grinding.

34. Method according to any one of claims 30 to 33, wherein the device (10) is assembled to a shaft (8), the ring (20) is forced against the hub (18) by the shaft (8).

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