Rotary bearing for positioning between a rotating element and a gearbox shaft

Description

[0001] The invention relates to the field of rotary bearings intended to be assembled between a gearbox and an internal combustion engine equipping a mobility device, and in particular a flywheel. It also relates to a method for assembling such a rotary bearing.

[0002] In powertrains using an internal combustion engine and a gearbox, a gearbox input shaft works in conjunction with the internal combustion engine crankshaft, notably to align these two components along the same axis. The internal combustion engine and the gearbox exhibit phases where their respective rotational speeds differ, for example, when the driver engages the clutch to change gears or when a gear-shifting system engages the gearbox to change gears. To address this, it is known to equip this powertrain with a rotary bearing that, on the one hand, centers the gearbox input shaft on the internal combustion engine crankshaft and, on the other hand, allows for a rotational differential between these two components.

[0003] Several types of bearings currently exist that provide this function of driving the gearbox's input shaft. The rotary bearing can be a "pilot" type bearing composed of either multiple rolling elements, such as a needle bearing or a ball bearing, sealed or not, or a single-piece ring, commonly called a plain bearing, made of a self-lubricating material such as bronze or copper.

[0004] Rotary bearings, of the "pilot" type, have drawbacks: they are complex and expensive to manufacture because they involve the use of a large number of parts, and require additional lubrication. Their durability depends primarily on the presence of this additional lubrication throughout the product's service life. The robustness of this type of bearing is linked to its ability to prevent lubricant or grease loss, making its design complex, as it must be adapted and adjusted to the characteristics of the chosen lubrication (grease or lubricant reservoir) and its environment (operating conditions).

[0005] Rotary bearings require the use of a seal in contact with the input shaft to prevent lubricant leaks that could contaminate the entire powertrain. The reliability of this bearing also depends on careful handling during installation, maintenance, or repair of the powertrain. Premature damage to this bearing can lead to excessive noise from the powertrain, as well as reduced functionality and performance. Repairing or replacing this type of bearing results in additional costs.

[0006] When these bearings are advantageously of the monobloc type, the previously indicated handling risks, as well as the risk of premature deterioration, are considerably reduced; however, the use of a monobloc ring results in a reduction of the performance and functional characteristics of the primary shaft control function, which significantly reduces their use.

[0007] These known monobloc type plain bearings currently on the market have technical limitations regarding the absorption of engine-gearbox misalignment, in addition to a coefficient of friction that is sometimes too high, which should be reduced.

[0008] US document 2003 / 012467 A1 discloses a rotary bearing with a conical section at the inner ring.

[0009] This pursuit of performance, in the function of absorbing shaft misalignment, in controlling friction and using a limited number of parts, is the basis of the invention.

[0010] The invention seeks to combine the advantages of two rotary bearing technologies (self-lubricating bearing and rolling bearing) into a single solution, offering a rotary bearing with a simplified design and a limited number of rings. The invention also aims to resolve all the aforementioned drawbacks by providing a simple, efficient, and economical solution.

[0011] The invention proposes a rotary bearing intended to be placed between a rotating member of an engine and a primary shaft of a gearbox, the rotary bearing being made up of at least two cylindrical rings, of axis X, being in contact with each other, of which: an inner ring adapted to be mounted press-fit or sliding on the primary shaft, and an outer ring adapted to be mounted press-fit in the rotating member, said cylindrical rings being configured to align the primary shaft with the rotating member, by means of at least one ring configured to achieve a degree of freedom and at least one ring made of a synthetic or composite material promoting sliding.

[0012] The invention proposes a rotary bearing intended to be placed between a rotating element of an engine and a primary shaft of a gearbox, the rotary bearing being made up of at least two cylindrical rings, with axis X, being in contact with each other, of which: an inner ring adapted to be press-fitted or sliding on the primary shaft, and an outer ring adapted to be press-fitted in the rotating element, the rotary bearing comprising at least a third ring housed at least partially in the outer ring, the at least a third ring forming a guide ring configured for the entry of the primary shaft into the rotary bearing, said cylindrical rings being configured to align the primary shaft with the rotating element, by means of at least one ring configured to provide a degree of freedom and at least one ring made of a synthetic or composite material promoting sliding,

[0013] By introducing an additional degree of freedom in a bushing, the primary shaft and the rotating component are aligned on the same axis. This absorbs any potential coaxiality errors at the bearing, thus improving the rolling resistance requirements of the primary shaft and the rotating component. This additional degree of freedom allows, for example, movement of the bushing in a transverse (axial), horizontal (radial), and / or angular direction, when mounted with another bushing or the primary shaft. This is because the bushing is designed to allow a single degree of freedom, due to its shape and / or material, with the primary shaft or another bushing with which it is mounted.

[0014] Thus, the said additional degree of freedom can be increased, thanks to at least one ring comprising the synthetic or composite material provided for in the design of the rotary bearing.

[0015] A separation of the rotational speed of the rotating element from the rotational speed of the primary shaft is also permitted, when necessary, by means of a ring made of a synthetic or composite material and having a sliding surface designed for this purpose. In other words, at least one synthetic or composite ring is configured to have a limited coefficient of friction, thanks to the fact that said ring is made of a synthetic or composite material that promotes sliding.

[0016] According to an additional feature of the invention, the limited coefficient of friction is less than 0.2, in particular less than 0.1.

[0017] The drag torque resulting from the rotation bearing according to the invention is then significantly lower than the drag torque resulting from the bearings of the prior art.

[0018] The cylindrical rings of the rotary bearing can be portions of a cylinder with a constant radius axis of revolution; according to a further feature of the invention, at least a third ring has a chamfer or a substantially conical shape. This shape improves shaft guidance during assembly onto the rotating member.

[0019] Such a rotating bearing may exhibit one or more of the characteristics described below, either combined or considered independently of each other: Advantageously, a ring of the rotary bearing, preferably the inner ring, can be configured to provide at least one degree of freedom with another ring or with the primary shaft, and can be made of a synthetic or composite material. In such a situation, other rings of the rotary bearing can also be made of a synthetic material, performing, in particular, other functions specific to them. This sliding composite material can be made of at least two materials of different natures, for example, PTFE (or Teflon), sintered bronze, brass, etc. This sliding synthetic material can be a polymer, for example, a plastic, which is capable of being molded or shaped, generally under heat and pressure.Any material removal operation used to create said ring is avoided; according to a further feature of the invention, the ring, made of a synthetic or composite material that promotes sliding, is mounted in contact with the primary shaft or another ring. According to a particular embodiment of the invention, the inner ring includes a sliding region (called a sliding surface) with the primary shaft or with another ring of the rotating bearing.This provides an axial (and in particular transverse) degree of freedom between the two components. This inner ring can be configured to provide a sliding connection with the primary shaft or the outer ring, by means of the sliding region. This sliding region can be formed on an external face of the inner ring to be configured to slide in contact with another ring, in particular the outer ring. Alternatively, or in addition, this sliding region can be formed on an internal face of the inner ring to be configured to slide in contact with the primary shaft. According to a particular embodiment of the invention, the inner ring of the rotary bearing may have a self-lubricating body, which incorporates lubricant into its material or its anti-friction layer. A self-lubricating material for the inner ring is, for example, synthetic or composite. No maintenance is required.The lubricant is uniformly distributed over the surface of the ring, reducing friction, even as its anti-friction coating begins to wear. According to another feature of the invention, the number of cylindrical rings in the rotary bearing is four or fewer, for example, two or three. By using a limited number of rings, the bearing's performance is improved compared to one-piece bearings. According to the invention, the rotary bearing comprises at least one additional ring, called a third ring, housed at least partially within the outer ring. This at least one additional ring can be made by molding. This at least one additional ring can be made of synthetic and / or composite material. Thus designed, this ring can have a flexible or pliable surface.

[0020] A flexible surface is defined as a flexible and rigid surface, preferably made of a composite material, in particular a polymer, for example plastic; A supple surface is defined as an elastically deformable surface, preferably made of a synthetic material, in particular a polymer, for example rubber; At least one additional ring may be interposed, at least partially radially, between the inner and outer rings. This additional ring may form an interlayer ring. This additional ring may be made of a synthetic or composite material, in particular a polymer, for example rubber, or any other polymer configured to be flexible. This additional ring may then form a damping ring. Thus arranged, this ring is configured to dampen the radial forces between the inner and outer rings. At least one additional ring may be positioned, at least partially axially, on one side of the inner ring, in particular on the gearbox side. Thus arranged, it is configured to facilitate the entry of the input shaft into the rotary bearing. This guide ring must allow the primary shaft to pass without interference or contact, thus avoiding any parasitic friction. This additional ring can be made of a synthetic material, particularly a polymer, for example, a plastic, especially a thermoformed plastic, or any other polymer configured to be flexible. This additional ring then forms a guide ring (called a primary shaft centering ring) configured to facilitate the entry of the primary shaft into the bearing and, in particular, into the inner ring. This guide ring is preferably conical in shape. This guide ring includes a conical bore defining a guide wall (also called a contact surface) configured to center the primary shaft. This guide wall may have a chamfered cross-section. According to a particular embodiment of the invention, the guide ring may be free of lubricant or grease.The absence of lubricants or grease simplifies this guide ring by eliminating its sealing function, unlike the prior art corresponding to pilot-type bearings with lubrication. According to another feature of the invention, the cylindrical rings of the rotating bearing can differ from one another in at least: material, thickness, hardness, shape, and axial length. These differences are described in more detail below. The outer ring can be made of metal, in particular a single sheet of metal. The inner ring can be made of metal, synthetic material, or composite material, in particular plastic. The outer ring can be made of a material with high density or hardness to ensure its fit in the rotating part without deformation that could impair its fit with the inner ring.The outer ring material is thus, for example, a metallic material, such as treated steel or stainless steel. The inner ring can also be rigid, with high density and hardness to allow friction with the treated primary shaft. The thickness of the outer ring can be limited to maintain clearance for the inner diameter of the rotating bearing. The outer ring thickness can be limited and thin.

[0021] The thickness of the outer ring may be less than the thickness of the inner ring, in particular less than 1 / 3 times the thickness of the inner ring; The thickness referred to here is the dimension measured along a radial direction of the ring in question, between an inner or internal face and an outer or external face of said ring. A face is understood to be a flat cross-sectional surface; in particular, the thickness of the outer ring may be less than the thickness of the additional ring, specifically less than 1 / 3 the thickness of the additional ring.

[0022] In particular, the additional ring may be made of one or more materials. For example, a strong and rigid material such as treated steel, covered with a synthetic or composite material, including plastic, rubber, elastomer, or any other polymer that promotes flexing or sliding; In particular, the inner ring may have an outer diameter that is smaller than the inner diameter of the outer ring. Alternatively, the inner ring may have an outer diameter that is larger than the inner diameter of the outer ring; At least one additional ring can be in a monobloc or bi-bloc form, that is to say made in the same mold and / or of the same material (for example before being split); This additional one-piece or two-piece ring can be made of a synthetic material, such as an elastomer; For example, the damping ring and the guide ring are made from the same material, preferably as a single piece. The advantage of a one-piece design is that it combines different functions. Alternatively, the damping ring and the guide ring can be made from the same material but are separate, with the material then split into two blocks. For example, they can be made from the same synthetic material and then radially split. The advantage of a two-piece design is that each block has its own specific function. The additional ring can also be made of two different materials, one block being plastic and the other rubber or elastomer.In both cases, the blocks of the additional ring are distinct and close together; at least one additional ring may include a base and, in particular, a guide track, notably circumferentially continuous, from which the inner ring is received; at least one additional ring may include a stop wall for the end of travel of the first ring; at least one additional ring has a housing suitable for receiving the inner ring. The inner ring may be integrated and integral with the additional damping ring at its inner diameter. This union may result from a thermoforming or plastic injection process.Thus, the inner ring and the intermediate ring form a single unit which, according to the embodiment detailed above, can include the guiding function by integrating the additional guide ring; According to another feature of the invention, the inner ring forms a smooth ring, in particular a bearing bushing, which is mounted to slide on the primary shaft, and whose internal contact surface is flat. Hence an increased degree of axial freedom; Designed in this way, the coefficient of friction is reduced, and the lifespan of the bushings is increased by transferring wear to the smooth ring. Operation is quiet.

[0023] The thickness of this smooth ring is less than that of the other rings in the rotary bearing. Hence, a reduced radial footprint and lower material cost; According to another feature of the invention, the inner ring is configured to provide a pivot joint with the primary shaft or with the outer ring. In other words, it is configured to allow the primary shaft to pivot while bearing against it. Misalignment is more acceptable; The inner ring thus includes a pivoting region, in particular an internal or external domed contact surface which is mounted with the primary shaft or with the outer ring.

[0024] The inner ring then forms a pivoting ring with a convex contact surface. internal which is mounted with the primary shaft, or external which is mounted with the outer ring.

[0025] A convex contact surface is configured for relative rotation around an axis perpendicular to the axis, the amplitude (called the ball joint angle) being small for the primary shaft; According to another feature of the invention, the inner ring is configured to provide a ball joint with the outer ring. In other words, it is configured to rotate the inner ring through a large amplitude (called the ball joint angle) for the primary shaft; The inner ring thus comprises an external spherical contact surface which is mounted with the outer ring. The inner ring then forms a spheroidal ring known as a ball joint. Designed in this way, this spheroidal ring is configured to increase the angle of contact between the inner and outer rings, the bearing then transmitting axial forces; According to another feature of the invention, the outer ring delimits an inner volume within which extends at least one other ring, preferably the inner ring or all the other rings of the rotation bearing; In particular, the outer ring forms a cage surrounding at least the inner ring, and especially all the other rings of the rotation bearing; As an example, the outer ring forms a flexible cage, the external contact surface of which is configured to achieve a radial degree of freedom in particular with the inner ring; According to another feature of the invention, the outer ring comprises a central boss configured to provide a linear contact surface with the inner ring; According to another feature of the invention, the outer ring comprises axial or rotational locking means for connecting at least one other ring, and preferably all the other rings, to the outer ring. The locking means may be provided by an end bearing face against which an edge of the inner ring bears; According to another feature of the invention, the outer ring comprises clamping means for mounting on the edges or slices of the inner ring, in particular within notches formed on said slices of the inner ring; For example, by means of axial locking: the outer ring and the inner ring can be fixed at least axially to each other. In particular, they can be fixed both axially and rotationally; For example, by means of rotary locking: the outer ring and the additional ring can be fixed at least rotationally to each other. In particular, they can be fixed both axially and rotationally; According to another feature of the invention, the rotating bearing consists of one to three molded rings, preferably made of various synthetic and / or composite materials, for example, plastic(s) and elastic(s). By way of example, at least one of said molded rings, in particular the inner or additional ring, can be made by injection molding into the outer ring, the inner volume of the latter then serving as a mold.

[0026] The invention also covers a method for manufacturing a rotary bearing, as described by the first aspect of the invention, intended to be placed between a rotating input member and a primary shaft of a gearbox, comprising at least the following steps: a) To produce, by stamping or deep drawing from a sheet metal, at least one ring, including an outer ring of the rotating bearing. In particular, said stamped or deep-drawn ring shall have at least one inner volume and a bottom, defining in particular a cage shape; b) To produce, by molding from a composite or synthetic material, at least one ring, including an inner ring of the rotating bearing, in particular made of polymer or plastic.

[0027] In particular, at least one molded ring has an internal or external sliding surface intended to be housed within the inner volume of the outer ring. Preferably, at least one molded ring has a shape complementary to the interior of the outer ring.

[0028] In particular, the rotation bearing consists of up to three rings molded from various synthetic and / or composite materials, for example plastic(s) and elastic(s).

[0029] As an example, a molded ring can be made by injection into the outer ring, the inner volume of the latter then serving as a mold.

[0030] Such a process incorporates all or part of the characteristics mentioned previously.

[0031] The invention also covers a method for assembling a rotating bearing, as described by the second embodiment, in a rotating part of an internal combustion engine, during which in a first step the first ring is housed in the rotating part, in a second step the second ring is placed on the primary shaft and then, in a third step the second ring is slid into the first ring, in particular by mounting a gearbox on the internal combustion engine.

[0032] Such a process incorporates all or part of the characteristics mentioned previously.

[0033] The invention also covers a clutch kit comprising at least one clutch disc, one clutch plate, and one rotary bearing according to the first aspect. Such a clutch kit is recognizable in that its components are assembled within a container, for example a cardboard box, so as to be distributed through after-sales networks.

[0034] The invention finally covers a powertrain comprising an internal combustion engine, a gearbox and a rotary bearing as detailed in this document, or a clutch kit as described above.

[0035] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and several illustrative and non-limiting examples of embodiments given with reference to the attached schematic drawings on the other hand, in which: There figure 1is a schematic representation of a powertrain mounted in a mobility device, particularly a motor vehicle; The figure 2 is an axial cross-section of a powertrain comprising a dual-mass flywheel; The figure 3 is an axial cross-section of a powertrain including a flywheel; The figure 4 is a schematic representation illustrating the forces and displacements exerted on the rotating bearing from the rotating member and the primary shaft, for understanding the invention; The figure 5 is a perspective of the rotation bearing according to a first embodiment of the invention; The figure 6 illustrates an axial cross-section of the rotation bearing of the first mode shown in the figure 1 ; There figure 7 illustrates a detailed axial cross-section of a pivot joint of the rotating bearing shown in the figure 2 ; There figure 8-1 and the figure 8-2illustrate in perspective and radial section examples of rotating bearings according to a second embodiment of the invention; The figure 9 illustrates an axial cross-section of the rotating bearing according to a third embodiment of the invention, comprising at least one additional ring, in particular a one-piece ring; The Figure 10 illustrates an axial cross-section of the rotating bearing according to a third embodiment of the invention, comprising at least one additional ring, in particular a two-piece ring; The figure 11 illustrates an axial cross-section of the rotating bearing comprising a first example of a ball joint according to a fourth embodiment of the invention; The figure 12 illustrates an axial cross-section of the rotating bearing comprising another example of a ball joint according to the fourth embodiment of the invention; The figure 13illustrates an axial cross-section of the rotating bearing comprising another example of a ball joint according to the fourth embodiment of the invention; The figure 14 and the figure 15 illustrate in radial and axial section a rotational bearing according to a fifth embodiment of the invention; The figure 16 and the figure 17 illustrate in perspective and radial section a rotation bearing according to a sixth embodiment of the invention;

[0036] The term "mobility device" refers to all motor vehicles, passenger vehicles, but also industrial vehicles, including heavy goods vehicles, public transport vehicles, and agricultural vehicles, or any transport device that allows a living being and / or an object to move from one point to another. This last type of device may have a hybrid engine, an electric engine, and / or a small mobility engine.

[0037] Unless otherwise specified, "axially" means parallel to the longitudinal axis X of the rotating bearing; "radially" means along a transverse axis intersecting the longitudinal axis X of the rotating bearing; "angularly" or "circumferentially" means around the longitudinal axis X of the rotating bearing. For ease of understanding, the terms "inside / internal" or "outside / external" will be used with respect to the X-axis and along a radial orientation orthogonal to said axial orientation; and the terms "rear" (AR) and "front" (AV) will be used to define the relative position of one element with respect to another along the axial direction, an element intended to be placed near the internal combustion engine being designated as rear and an element intended to be placed near the gearbox being designated as front.

[0038] In the rest of the description and claims, certain elements can be indexed as: the first, second, and third rings. This is simply indexing to differentiate and name similar but not identical elements. Indexing does not imply any priority of one element over another, and such designations can easily be interchanged without departing from the scope of the description.

[0039] We illustrated on the figures 1 to 5 a first embodiment of the invention.

[0040] THE figures 1 to 2These figures illustrate a powertrain 2 configured to propel a vehicle. This powertrain 2 comprises a transmission engine 4, here an internal combustion engine, and a gearbox 6 attached to and fixed to the internal combustion engine 4. Alternatively, the engine 4 may be a hybrid, electric, and / or small mobility type. The powertrain 2 also includes a clutch 1 installed between the transmission engine 4 and the gearbox 5, whose function is to couple or decouple the engine 4 from the gearbox 5.

[0041] The clutch 1 includes various parts such as at least one disc 3, otherwise called a friction disc, configured to transmit the energy from the engine 4 to the gearbox 5 when it is kept in contact, in particular against a flywheel, for example a flywheel, by a support force generated by a plate 7, otherwise called a pressure plate or push cover.

[0042] The clutch 1 is formed from a clutch kit comprising at least said disc 3, said pressure plate 7, and a rotating bearing B according to the invention. The clutch kit may also include a release bearing 8 configured to press on the pressure plate 7 so as to release the pressure force on the disc 3 and thus disengage the engine 4 from the gearbox 5. The release bearing 8 is controlled by a vehicle driver or by an automated vehicle system.

[0043] The rotation bearing B aligns coaxially a rotation axis of a rotating element 40 of the engine 4, in particular a flywheel or a crankshaft, with a rotation axis of a primary shaft 50 constituting the gearbox, while allowing rotation between this primary shaft 50 and the rotating element 40.

[0044] The rotating element can be a flywheel, for example a primary flywheel 41 of a double damper flywheel (see the figure 2 ) or a 42mm flywheel (see the alternative in figure 3 ).

[0045] The rotating part 40 can be an output hub of a flywheel or crankshaft.

[0046] The rotating bearing B comprises at least two rings 10, 20 mounted coaxially, one inside the other and in contact with each other. The rings, two in number in the first mode, share a longitudinal axis X visible on the figures 2 to 15and are portions of a circular cylinder. The set of rings in the rotary bearing is configured to correct any misalignment, and thus align the primary shaft with the rotating element, regardless of the stresses exerted between them.

[0047] One of said at least two rings is configured to fit into the rotating member 40 and another of said at least two rings is configured to be mounted on the primary shaft 50 of the gearbox 5, for example mounted in a sliding manner.

[0048] There figure 4This diagram illustrates, for the sake of clarity regarding the invention, the stresses exerted by the primary shaft and the rotating member on the rotary bearing. It schematically represents: the axial loads and resulting deflections (respectively, "axial load" La and "deflection under axial load" dLa); the radial loads and resulting deflections (respectively, "radial load" Lr and "deflection under radial load" dLr); the torsion angle and the conical angle α. These latter factors can misalign the primary shaft and the rotating member, both during operation of the rotary bearing and when the primary shaft is mounted.

[0049] The rotating bearing according to the invention is remarkable in that the set of rings of the rotating bearing is configured to correct any misalignment, and thus align the primary shaft with the rotating member, regardless of the aforementioned stresses exerted between them.

[0050] To achieve this, rings 10, 20 are made of different materials, at least one of them being a synthetic or composite material which has properties which reduce friction, or even improve its sliding, especially for a synthetic material.

[0051] By virtue of its shape and / or the material used, at least one ring of the rotary bearing is configured to provide a degree of freedom with the primary shaft or another ring of the rotary bearing. Such a shape, designed for this purpose, being domed, spherical, or conical, can provide contact of the pivot, ball joint, or thrust type, respectively, with the primary shaft or another ring of the rotary bearing. Alternatively or in addition, a material designed for this purpose, such as a synthetic or composite, can provide sliding, flexible, or pliable contact.

[0052] The first embodiment thus proposes a rotation bearing consisting, for example, solely of two rings threaded one inside the other, a rotational sliding surface between the two rings being present on an internal face of the ring made of synthetic material promoting sliding, whether this is placed inside the second ring or around the latter.

[0053] The rotary bearing is remarkable in that it is free of cylindrical, tapered, or ball rolling elements. Each rotary bearing consists solely of cylindrical rings extending along the X-axis. These rotary bearing rings are based on friction bearing technology rather than rolling element technology, resulting in higher load capacity, improved shock resistance, and a larger contact area. Each cylindrical ring is centered on the X-axis of the rotary bearing.

[0054] The rotary bearing according to the invention is remarkable in that it comprises a limited number of cylindrical rings, preferably between two and four. It uses a reduced number of components, significantly fewer than the rolling elements of a roller bearing (needle or ball type). This reduces manufacturing costs as well as the assembly and reliability risks of the rotary bearing.

[0055] In the first embodiment, these two rings are a first, called inner ring 10, and a second, called outer ring 20. Advantageously, the second ring 20 is configured to fit inside the rotating member and be in contact with it. This second ring 20 is press-fitted or press-fitted either inside the rotating member 40 (see the figures 5 to 7 And figures. 9 to 15 ) either with the primary tree (see the Figures 8-1 and Figures 8-2 of the second mode).

[0056] In the illustrated examples, the diameter of the outer face of the second ring 20, called outer diameter D2 of the first ring, is made according to a tight fit which guarantees that the first ring is held inside a counterbore made in the rotating part.

[0057] Therefore, the first ring 10 has an outer diameter D1', D1" which is less than the inner diameter D2' of the second ring 20.

[0058] In an alternative not shown, the diameter of the outer face of the first ring, referred to as the outer diameter D1', D1" of the first ring, can be achieved using a sliding fit that ensures axial sliding without radial play of the first ring within a counterbore in the rotating element. Consequently, the first ring can have an outer diameter greater than the inner diameter of the outer ring. Furthermore, the second ring 20 is made of a material with a hardness greater than that of the material constituting the first ring 10. For example, the material of the second ring 20 is a metal, such as steel, stainless steel, or an aluminum alloy.

[0059] The first ring 10, on the other hand, is a self-lubricating ring, that is to say, made of a synthetic material that promotes sliding, such as Polytetrafluoroethylene (PTFE) or a self-lubricating plastic.

[0060] In other words, a ring made of porous metal (including porosities between 15 and 35% of the volume), with incorporation of lubricant (oil, graphite, etc.) in the porosities.

[0061] During relative movement between these rings, the lubricant from the self-lubricating ring will diffuse through the pores (between 15 and 35% of the volume) of the antifriction layer and coat its surface. The structure of a self-lubricating ring, comparable to a sponge, releases the oil during the operation of the rotating bearing and absorbs it when the rotating bearing stops.

[0062] A self-lubricating bushing requires no maintenance or grease, thus increasing the lifespan of the rotary bearing. The self-lubricating synthetic material is suitable for high accelerations and speeds (4000 rpm) and static and dynamic loads (C / C0) exceeding 300 N.

[0063] In the first embodiment, the figures 5 to 7These figures illustrate the rotational bearing B where the first ring 10 is positioned within the second ring 20, preventing rotational movement between these two rings. Rotational movement between the first ring 10 and the second ring 20 is prevented by a rotational locking mechanism, achieved through complementary shapes. The shape of the second ring 20 is complementary to the shape of the first ring 10 and adapted to lock the latter.

[0064] According to one example, the means of locking against rotation is a tooth which cooperates with a groove, the tooth and groove being made on one and the other of the rings 10, 20.

[0065] This locking mechanism limits one degree of freedom, at a minimum one rotation, but it allows axial sliding of the first ring 10 relative to the second ring 20, so that one can fit inside the other. This allows an additional degree of freedom, in this case axial.

[0066] Alternatively, the first ring 10 and the second ring 20 can be joined together, according to a hyperstatic assembly.

[0067] For example, the first ring 10 can be injection molded inside the second ring 20, the latter then serving as a mold.

[0068] Furthermore, the second ring 20 is configured to be housed in the rotating part 40.

[0069] There figure 6 illustrates a section AA visible on the figure 5 On this figure 6 , the first ring 10 has a thickness E1 greater than a thickness E2 of the second ring 20. As an example, E2 can be equal to about 1 mm.

[0070] Thicknesses E1 and E2 are measured along a transverse axis T perpendicular to the X axis of the rotation bearing B respectively: for thickness E1, between the internal surface 11 and an external surface 12 of the first ring 10; for thickness E2, between an internal face 21 and an external face 22 of the second ring 20.

[0071] Thickness E1, measured along a transverse axis T, can be the minimum thickness of the first ring 10. Thickness E2, measured along a transverse axis T, can be the maximum thickness of the second ring 20. In particular, thickness E1 is defined between the inner diameter D1 and the outer diameter D1' or D1" of the first ring. Thickness E2 is defined between the inner diameter D2' and the outer diameter D2 of the second ring.

[0072] In the first mode, the first ring 10 has a variable thickness E1 which is greater than a variable thickness E2 of the second ring 20, in particular greater than or equal to 3 times the thickness of the second ring.

[0073] There figure 6shows the presence of a flank formed on the second ring 20, at one of its longitudinal ends. Such a flank forms a stop with respect to the first ring 10, limiting the translation, called the end of travel, of the first ring 10 in the second ring 20 along the X axis.

[0074] Furthermore, the second ring 20 comprises an internal volume delimited between a first part delimited by the bottom of the ring 20, from which the inner ring 10 is housed, and; - a second part (of radial extension) delimited by the terminal face(s) 23 of support, configured to receive (each) an edge 13 of the first ring 10.

[0075] It should be noted that, according to this first embodiment of the invention, the first ring 10 is axially housed in the second ring 20, the latter being made in the form of a cage.

[0076] A cage is defined as a ring 20 having lateral walls on its end faces. The lateral walls, together with the bottom, define the internal volume of the ring 20. In other words, a ring 20 whose dimensions extend axially beyond each end face of the first ring 10, so as to surround the other cylindrical ring(s) of the bearing.

[0077] In the first embodiment, the first ring 10 is positioned within the second ring 20, with axial and radial movement between these two rings prohibited. The second ring 20 thus defines an internal volume, a first part of which is occupied by the first ring 10 and a second part configured to receive the primary shaft 50.

[0078] In this first embodiment, the first ring 10, called the inner ring, is made of a synthetic material that facilitates sliding, for example, rotation between the primary shaft and the rotating member. This sliding region is common to the different embodiments illustrated, and is hereafter referred to as 100, 110, 100', or 310 depending on the embodiment.

[0079] Advantageously, this sliding region can be formed on the inside of a ring, for example, at a primary shaft mounting area, particularly through direct contact with the primary shaft. Alternatively, or additionally, this sliding region can be formed on the outside of a ring, for example, at a mounting area receiving another adjacent ring of the rotary bearing.

[0080] In this first embodiment, the surface that allows rotation between the primary shaft and the rotating member is the inner surface 11 of the inner ring 10. Furthermore, this first ring 10 is configured to be slidably mounted on the primary shaft 50. The inner surface 11 of the first ring 10 is designed to accept rotation, thus allowing one degree of freedom. The inner surface 11 defines the central region of the first ring 10.

[0081] Furthermore, the first ring 10 has a lateral face called edge 13, which bears against an end face 23 of the second ring 20. The end face 23 bearing the second ring 20 can define a stop 230, of shapes complementary to the edge 13 of the first ring 10.

[0082] The edge 13 can result from a molding of the first ring 10.

[0083] The stop 230, or end face 23, which supports the second ring 20, can be formed by deep drawing or stamping, for example, cold stamping. The end face 23 is understood to be one of the edges of the ring 20. In other words, it represents a radial variation in thickness ΔE2 relative to the rest of the second ring. The end face 23, against which an edge 13 of the inner ring bears, forms an axial locking mechanism for the rings 10, 20. The stop 230 thus forms an axial locking mechanism for the rings 10, 20.

[0084] As an example, the second ring 20 is axially delimited between two terminal faces 23, each forming a stop 230.

[0085] In the presence of this stop 230, the second ring 20 extends axially beyond the edge 13 of the first ring 10. Thus, the stop 230 is proportional to the thickness E2 of the ring 20. The variation ΔE2 in thickness is relatively small, less than 0.3 times the thickness E2 of the ring 20. The edge 13 and / or the stop 230 ensure the axial position of the second ring 20 relative to the first ring 10, while allowing rotation of the second ring 20 within the first ring 10.

[0086] Furthermore, the stop 230 is made from the material of the second ring 20. The stop results from a mechanical deformation, in particular a stamping, of the second ring 20.

[0087] THE figures 6-7They illustrate in detail an example of an improved sliding assembly with the primary shaft, in which the internal surface 11 of the first ring 10 defines a pivoting region 110 with the primary shaft. In other words, an area where the centering of the primary shaft relative to the first ring takes place, resulting from the mounting of said shaft.

[0088] The first ring 10 thus forms a bearing or pivot ring with respect to the primary shaft, notably by supporting it. The pivot region 110 defines a curved contact surface, preferably convex, which is configured to allow pivot movement between the first ring 10 and the primary shaft 50.

[0089] This allows for at least one combined degree of freedom (here, axial and radial). In particular, a degree of freedom that is superior to current state-of-the-art bearings, and significantly higher than needle roller bearings or solid block bearings.

[0090] The pivoting region 110 is formed with a thickness variation ΔE1 in the radial direction, relative to the rest of the second ring. The pivoting region 110 is proportional to the thickness E1 of the ring 10. The thickness variation ΔE1 is relatively small and less than 0.3 times the thickness E1 of the ring 10.

[0091] As an example, the first and second rings include complementary means for rotational locking, achieved through a concave-convex interaction of the internal and external surfaces of the first and second rings. In particular, the external surface of one of the rings can be convex and receive within the internal surface of the other ring.

[0092] In the second embodiment of figures 8-1 to 8-2The positions of the first and second rings are reversed. Therefore, the second ring 20 is press-fitted or press-fitted to the primary shaft. The first ring 10, on the other hand, is configured to fit within the rotating element 40. Thus, the second ring 20 is positioned within the first ring 10.

[0093] Specifically, the first ring 10 is configured to slide on the second ring 20. Thus, the second ring 20 presents a pivoting region 110' at their contact point, located between the two rings. This pivoting region 110' is the area where sliding occurs between the first ring 10 and the second ring 20, resulting in particular from clutch actuation. This sliding is made possible by the fact that the first ring 10 (here, the outer ring) is coated on its inner surface 11 with a synthetic material (PTFE type) that promotes sliding, and advantageously, by the fact that the second ring 20 is composed of two materials: on its outer part, a metallic outer face 22, of the sheet metal type, allowing friction and rotation with the inner surface 11.

[0094] In addition, this pivoting region 110' is formed by the external surface 12 of the first ring 10 and by the inner face 21 of the second ring 20. The second ring 20 thus forms a bearing or pivoting ring with respect to the first ring 10, in particular by carrying the latter.

[0095] The second embodiment of the rotating bearing B can be manufactured and assembled as follows: in a first step, the first ring 10 is placed in the rotating member 40 so that its outer surface 46 comes into contact with the rotating member 40. In a second step, the second ring 20 is placed or slipped onto the primary shaft 50, in particular because the inner face 44 of the second ring 20 has a sliding fit on the primary shaft 50. In a third step, the second ring 20 is slid into the first ring 10, either alone or at the same time as a gearbox 6 is mounted on the engine 4.

[0096] In particular, in the example of the figure 8-2 The end face 23, and in particular the stop 230, of the second ring 20 can extend radially in the form of a flange. This ensures the axial position of the second ring relative to the first ring. This stop 230 results from a mechanical deformation, specifically a stamping, of the second ring.

[0097] The third embodiment illustrated in figures 9 to 10 This is substantially similar to the first mode, except that elastic damping means are provided between the first and second rings to allow one degree of freedom. This is to dampen the forces within the rotating bearing and reduce the surface pressure applied by the primary shaft 50.

[0098] Similar to the first embodiment, the inner ring 10 is made of a synthetic material that promotes sliding. Thus, the surface that allows rotation between the primary shaft and the rotating member is the internal surface 11 of the inner ring 10.

[0099] Furthermore, the first ring 10 is configured to be slidably mounted on the primary shaft 50. The internal surface 11 of the first ring 10 is designed to allow rotation. Hence, an additional axial degree of freedom; The figures 9 to 10 illustrate in detail an example of an improved sliding assembly with the primary shaft, in which the first ring 10 forms a smooth ring called a bushing (also called a pleated bearing) with respect to the primary shaft, the first ring 10 being advantageously made of the self-lubricating material which promotes sliding with the primary shaft.

[0100] Furthermore, the rotating bearing B also includes at least one additional ring, called the third ring, which provides the elastic means. This additional ring is housed inside the second ring 20, in the bottom of the latter's internal volume and / or on one side of it.

[0101] This additional ring can be a damping ring 30, which is mounted and radially interposed between the first and second rings 10 and 20. This damping ring 30 is then configured with increased bearing elasticity against the radial forces from the primary shaft acting between the inner ring 10 and the outer ring 20. Thus, the inner and outer elastic contact surfaces of the damping ring 30 are designed to attenuate the resulting radial forces with the first and second rings, respectively. This allows for deflection within the rotary bearing.

[0102] The damping ring 30 is made of a polymer to ensure the increased elasticity of the rotating bearing, for example, a rubber-based material. In other words, it is made of a material with a low coefficient of friction, yet which remains stable. Furthermore, the inner face of the damping ring 30 defines a base and, in particular, a guide region for the first ring 10 and the primary shaft. This guide region forms the sliding region. This improves friction behavior by reducing the coefficient of friction.

[0103] The inner face of the damping ring 30 is then prepared to receive the first ring 10, in particular in a form complementary to the first ring 10.

[0104] It can define the sliding region for the stroke of the first ring 10, called the guide track, and advantageously a stop called the stop wall 330 for the end of the stroke of the first ring 10. In the presence of this stop 330, the damping ring 30 protrudes axially from the terminal face 13 of the first ring 10.

[0105] This stop 330 thus forms a means of axially locking the said rings 10, 20.

[0106] The stop or retaining wall 330 can ensure a maximum safety margin allowing axial movement, called sliding play j, to adjust the axial position of the second ring 10 relative to the second and third rings, while allowing rotation of the first ring 10 with the primary shaft.

[0107] Furthermore, this additional ring is a guide ring 35 positioned near the opening of the rotating bearing, configured to center the primary shaft entering the bearing. The guide ring 35 comprises a tapered bore, also called a cup, in other words, an angular guide wall 350, extending over 360 degrees, which is shaped to guide and center the primary shaft along the X-axis.

[0108] This guide wall 350 is beveled, meaning it has an oblique shape, i.e., a radial orientation and is inclined at an angle α' defined relative to the X-axis, to guide and center the primary shaft along the X-axis. This angle α' is related to the pivot angle α of the primary shaft. This angle α' is between 10 degrees and 80 degrees, here equal to 45 degrees.

[0109] This guide ring 35 can then be configured to protect the sliding region 310, in this case the sliding joint. In other words, to protect another ring made of synthetic or composite material, which is here the first ring 10.

[0110] This guide ring 35 is housed in the second ring 20, in the bottom of the latter, and is advantageously mounted to bear against the bottom of the second ring 20. This guide ring 35 can be configured with increased flexure or elasticity of the bearing in the face of the force coming from the primary shaft and acting on the inner ring 10.

[0111] The guide ring 35 is made of polymer to ensure greater flexibility or elasticity of the rotary bearing, for example, in a plastic-based material. The guide ring 35 does not form a seal here: it is free of any sealing device.

[0112] In the example of the figure 9 The damping rings 30 and guide rings 35 can be made from the same material and are advantageously manufactured as a single piece, referred to as the third ring. This third ring is then a single piece in shape. This third ring 30, 35 extends entirely within the internal volume of the second ring 20.

[0113] Furthermore, a housing is provided in the damping ring 30, from the inner face, and opened radially inwards, so as to house the first ring 10.

[0114] The housing can be formed from the radially internal periphery of the damping ring 30, preferably by molding. Such a housing for the damping ring 30 is delimited by said sliding regions and retaining wall.

[0115] This housing is open on one side of the bearing, in particular on the side opposite the gearbox, and it is advantageously of dimensions adapted to those of the first ring 10.

[0116] In an alternative not shown, the third ring is of bi-block form: the damping rings 30 and guide rings 35 can then be distinct from each other, being made from the same material (initially the third ring), subsequently split radially into two blocks to make these damping rings 30 and guide rings 35.

[0117] In the alternative example of the Figure 10The damping ring 30 and the guide ring 35 are distinct from each other, being made of different materials with different densities or hardnesses. The damping ring 30 extends partially within the internal volume of the second ring 20. The guide ring 35 preferably extends within the internal volume of the second ring 20. Hence, a rotary bearing has four cylindrical rings, each made differently in shape and material. Each ring is assigned a specific function, which improves their performance. We choose: For the damping ring 30, a material and density solely related to the damping of the rotary bearing, preferably synthetic rubber. For the guide ring 35, a material and density solely related to the protection of the rotary bearing, preferably thermoformed plastic.

[0118] In the illustrated examples, the damping ring 30 and the guide ring 35 are separate and can be brought close together. They are arranged axially opposite each other, advantageously inside the second ring 20.

[0119] The second ring 20 then delimits a bottom and advantageously an internal volume, within which extends in its entirety at least a third ring, in particular the damping and guiding ring(s).

[0120] Note that, in the illustrated examples, rings 10, 20, 30, and 35 are made of different materials, different shapes, and different dimensions. Thus, in the illustrated examples: the first ring 10 has a thickness E1 strictly less than the thickness E2 of the second ring 20; the second ring 20 has a thickness E2 strictly less than the thickness E3 of the third ring; the first ring 10 has a length L1 strictly less than the length L2 of the second ring 20; and the third ring has a length strictly less than that of the first and second rings.

[0121] For example: The length L2 of the second ring 20 can be approximately 20 mm.

[0122] The outer diameter D2 of ring 20 can be approximately 17 mm.

[0123] The inner diameter D2' of ring 20 can be approximately 15 mm.

[0124] The outer diameter D1' of ring 10 can be approximately 24 mm.

[0125] The fourth embodiment illustrated in figures 11 to 13 This design is essentially similar to the first, except that ball-joint connections are provided between the first and second cylindrical rings (10, 20) to allow for one degree of freedom. This absorbs the forces due to the nutation movements of the transmission and the rings, thereby slowing wear and fatigue on both the input shaft and the rotating component.

[0126] THE figures 11, 12 and 13 illustrate different possible examples, according to the fourth mode, of mounting a ball joint type connection between the first and second rings 10, 20.

[0127] The first ring and the second ring are complementary in shape.

[0128] The first ring 10 forms a spheroidal ring called a ball joint ring, which is preferably delimited by an external spherical or convex contact surface 120.

[0129] The contact surface 120 is provided on the radially external periphery of the second ring, preferably by molding.

[0130] Furthermore, this spheroidal ring is mounted in a hinged (or ball-jointed) configuration with the second ring, within an internal volume of the second ring specifically designed for this purpose. The internal volume of the second ring 20 is defined by a convex shape, advantageously complementary in form to the spheroidal ring. The ball-joint angle α between the rings 10 and 20 is increased.

[0131] Similar to the first embodiment, the inner ring 10 is also made of a synthetic material that promotes sliding. Thus, the surface that allows rotation between the primary shaft and the rotating member is the internal surface 11 of the inner ring 10. Furthermore, the first ring 10 is configured to be slidably mounted on the primary shaft 50. The internal surface 11 of the first ring 10 is designed to accept rotation. Hence, an additional axial degree of freedom;

[0132] Similar to the third embodiment, the rotating bearing B also includes at least one additional ring, called the third ring, which provides the elastic means. This additional ring is housed inside the second ring 20, either in the bottom of the latter's internal volume or on one side of it.

[0133] In the alternative of the figure 11, the additional ring of the rotary bearing can be a guide ring 35 disposed near the opening of the rotary bearing, so as to be configured to center the primary shaft inserting into the bearing inlet.

[0134] This guide ring 35 is housed in the second ring 20, advantageously mounted to support the bottom of the second ring 20.

[0135] This guide ring 35 can then be configured to protect the sliding region referenced here as 310, in this case that of the ball joint. In other words, to protect another ring made of synthetic or composite material, which is here the first ring 10.

[0136] This guide ring 35 can be configured with increased flex or elasticity of the bearing in the face of the force from the primary shaft and exerted with the inner ring 10. The guide ring 35 is made of polymer, to ensure such increased flexibility or elasticity of the rotating bearing, for example in a plastic-based material.

[0137] In the alternative of the figure 13The additional ring of the rotary bearing can be a damping ring 30, which is mounted and radially interposed between the first and second rings 10 and 20. This damping ring 30 is configured with increased elasticity of the bearing against the radial forces from the primary shaft acting between the inner ring 10 and the outer ring 20. Thus, the inner and outer elastic contact surfaces of the damping ring 30 are designed to attenuate the resulting radial forces with the first and second rings, respectively. This allows for deflection within the rotary bearing.

[0138] In this fourth configuration, the spheroidal ring can also be mounted in a articulated (or ball-joint) configuration with the damping ring 30. The internal volume of the second ring 20 receives the third ring, also called the damping ring 30, which in turn receives the spheroidal ring. The first, second, and third rings have complementary shapes. The ball-joint angle α between the rings 10, 20, and 30 is increased.

[0139] The fifth embodiment illustrated in Figures 14 to 15 , is substantially similar to the first mode, except that flexible deformation means are provided on the second ring 20, to allow at least one degree of freedom.

[0140] Thus the rotation bearing defines an external cage, shaped like a "U" in section.

[0141] Furthermore, the outer cage is configured flexibly to allow radial movement of the first ring at the bottom of the cage. Additionally, the outer cage is configured flexibly to absorb misalignment with the primary shaft, particularly at the first ring, in the event of a high radial load from the primary shaft.

[0142] This flexible outer cage is made from a thin sheet of metal, less than 10 mm thick. This metal sheet is approximately 0.8 mm thick. This thinness ensures better flexibility, particularly at its center, where it contacts the other cylindrical ring(s).

[0143] In this fifth mode, the flexible outer cage surrounds the first ring, whose external contact surface is configured to be flexible and to achieve a radial degree of freedom. This surface is located within an internal volume delimited by the flexible outer cage. Thus, the internal contact surface of the flexible cage is configured to deform upon contact with the first ring 10. The first ring 20 defines an internal plain bearing, which can be self-lubricated.

[0144] The second ring 20 defines the flexible outer cage. Therefore, the first ring 10 is rotationally fixed to the second ring 20. No rotational movement is permitted, which ensures that the first ring 10 slides only with the primary shaft, at the level of the internal surface 11.

[0145] In addition, the thickness of the second ring 20 is more than three times the thickness of the first ring 20, preferably less than five times the thickness of the first ring 20. This order of magnitude guarantees a low specific stiffness of the second flexible ring 20.

[0146] This flexible outer cage has in its center a central boss-shaped contact surface 210, which forms a linear contact over its entire circumference with the first ring 10.

[0147] This central boss 210 is configured to allow pivoting movement (primary shaft pivot angle α) of the first ring inside the second flexible ring, in contact with the latter. In other words, to provide another degree of freedom. The shape of the boss 210 central is provided for this purpose, being domed or convex; The height of the central boss 210 is approximately 0.5 mm thick.

[0148] This central boss 210 is designed to deform flexibly, allowing for a certain amount of radial play, in other words, a radial displacement of another ring at its center. Therefore, the first ring has an angular position under load that adjusts as needed once the shaft is fitted; the first ring can pivot on the central boss, and thus adapt to any misalignment.

[0149] The sixth embodiment illustrated in Figures 16 to 17 This configuration is substantially similar to the first mode, except that the second ring 10 is located within the first ring 20. The shapes and functions of the rings are thus reversed, mutatis mutandis, compared to the first mode. The second ring 20 has a lateral face, called the edge 23', which bears against an end face 13 of the first ring 10. This end face 13, which bears against the first ring 10, can define a stop 130, with shapes complementary to the edge 23' of the second ring 20.

[0150] The two rings 10 and 20 have on their internal surfaces 11 and inner face 21 a synthetic coating allowing sliding between the two rings 10, 20, but also between the inner ring 10 and the primary shaft of the gearbox 50. Therefore, the second ring 20 is configured to be housed in the ring 10 and mounted in the rotating member 40 by means of a tight fit.

[0151] This sliding is made possible by the fact that the second ring 20 is coated on its inner surface 21 with a synthetic material (PTFE type) that promotes sliding. In other words, the sliding region 100' is formed by the inner surface 21 of the second ring 20.

[0152] In this sixth embodiment, such a rotating bearing B doubles the number of rolling surfaces compared to the other embodiments mentioned previously. The sliding fit between the two rings 10, 20, as well as the sliding fit of the inner ring 10 with the primary shaft 50, thus provides a degree of radial freedom necessary for the misalignment absorption function of the primary shaft 50.

[0153] Compared to the first embodiment, the use of two sliding surfaces optimizes and better distributes the radial load generated by the misalignment of the primary shaft 50 with the rotating element 40. This radial load is applied over an increased contact and friction surface; this characteristic allows for an increase in the maximum permissible surface pressure for a given rotational speed.

[0154] The main advantage of this sixth embodiment is that it reduces the technical requirements concerning the synthetic material used for coating the friction surfaces of the two rings, thus extending its durability and its capacity for use and application.

[0155] Furthermore, the inner ring 10 defines a cage surrounding at least the outer ring. The use of a U-shaped inner ring with axial clearance "J," allowing movement between the two rings, provides the degree of freedom necessary for absorbing axial vibrations from the engine. Moreover, the U-shaped cross-section of the inner ring 10 serves to limit the axial movement of the outer ring 20 relative to the inner ring 10, while ensuring a radial and axial contact surface with a coefficient of friction suitable for sliding.

[0156] The present invention is not limited to the means and configurations described and illustrated herein, and also extends to any equivalent means and configuration as well as any technically operative combination of such means.

[0157] The use of the verbs "to include," "to comprise," or "to include," and their conjugated forms, does not preclude the presence of elements or steps other than those stated in a claim. In claims, any parenthetical references should not be interpreted as a limitation of the claim.

[0158] The dimensions shown or illustrated may not be to scale and correspond only to a specific torque limiter model developed by the applicant. The manufacturing process according to the invention will be adapted as needed to other nominal diameters of the rotating bearing and other thicknesses of its bushings.

Claims

1. Rotation bearing (B) intended to be placed between a rotating member (40) of an engine and a primary shaft (50) of a gearbox, the rotation bearing consisting of at least two cylindrical rings (10, 20, 30, 35), with axis X, being in contact with each other among which - an inner ring (10) adapted to be mounted tight or sliding on the primary shaft. - an outer ring (20) adapted to be mounted tight in the rotating member, the rotation bearing (B) comprising at least a third ring (30, 35) housed at least partly in the outer ring, the at least one third ring (30, 35) forming a guide ring (35) configured for the entry of the primary shaft into the rotation bearing, - made of polymer particularly synthetic plastic, - said cylindrical rings (10, 20, 30, 35) being configured to align the primary shaft with the rotating member, by means of at least one ring (10, 20, 30, 35) configured to provide a degree of freedom and at least one ring (10, 20, 30, 35) made of a synthetic or composite material promoting sliding.

2. Rotation bearing (B) according to claim 1, wherein a ring (10, 30, 35) preferably the inner one (10), is both made of synthetic or composite material and configured to provide at least one degree of freedom with another ring or with the primary shaft.

3. Rotation bearing (B) according to claim 1 or 2, wherein it comprises a number of cylindrical rings (10, 20, 30, 35) less than or equal to four.

4. Rotation bearing (B) according to any one of the preceding claims, wherein at least one of the cylindrical rings preferably the inner one (10), is self-lubricated, and wherein the inner ring (10) is made of synthetic material or composite, preferably plastic.

5. Rotation bearing (B) according to any one of the preceding claims, wherein said cylindrical rings (10, 20, 30, 35) are all different in at least: material, density or hardness, shape, thickness (e1, e2, e3) and length (11, 12, 13).

6. Rotation bearing (B) according to any one of the preceding claims, wherein the inner ring (10) forms a smooth ring called a bushing mounted sliding on the primary shaft, the outer diameter (D1', D1") of the inner ring (10) being preferably less than the inner diameter (D2') of the outer ring (20).

7. Rotation bearing (B) according to any one of claims 1 to 6, wherein: - the inner ring (10) forms a pivoting ring, comprising a curved contact surface (110, 110') internal or external which is mounted with the primary shaft or with the outer ring, or - the inner ring (10) forms a spheroidal ring called a ball joint, comprising an external spherical contact surface (120) which is mounted with the outer ring.

8. Rotation bearing (B) according to any one of the preceding claims, wherein the outer ring (20) is defined by at least: - a shape configured to fit into the rotating member and be in contact with it; - a material of metal sheet, of a hardness greater than that of the inner ring; - an interior volume within which extends at least one other ring (10, 30, 35), preferably all the other rings of the rotation bearing; and / or - axial or rotational blocking means intended to link at least one other ring (10), and preferably all the other rings, to the outer ring (20), the blocking means being for example made by a terminal face (23) of support against which an edge (13) of the inner ring comes to rest.

9. Rotation bearing (B) according to any one of claims 1 to 8, wherein the outer ring (20) is defined by at least: - a cage shape, preferably flexible, surrounding the inner ring, - a central boss (210), preferably flexible, on which the inner ring rests, - clamping means (25) intended to be mounted on the edges of the inner ring, particularly within external notches (15) provided on the edges of the inner ring.

10. Rotation bearing (B) according to any one of claims 1 to 9, wherein the at least one third ring is made of synthetic or composite material, preferably made by molding, particularly plastic or rubber, preferentially in a monoblock or bi-block form.

11. Rotation bearing (B) according to any one of claims 1 to 10, wherein the at least one third ring forms a damping ring (30) configured to dampen radial forces between the inner and outer rings, made of polymer particularly synthetic rubber or composite.

12. Rotation bearing (B) according to any one of the preceding claims, wherein the rotation bearing consists of one to three molded rings, for example at least one of said molded rings being made by injection into the outer ring (20), the interior volume of said outer ring (20) then serving as a mold.