Spring end stop vane secured to damped flywheel

Abstract

The invention relates to a damping flywheel (2) for a moving vehicle, comprising:-a central hub (20), the material extension of which forms a central plate (21),-a circular cavity (400) with an axis (X), located outside the central plate (21), inside which at least two damping springs (4) of curved shape are accommodated, and an end stop vane (5) arranged against an adjacent end (40) of the spring (4), said at least one end stop vane (5) being partially housed inside the central plate (21) and fixedly attached to the central plate (21).

Description

Technical Field

[0001] The present invention relates to a damped flywheel, such as an engine flywheel or a dual mass flywheel, for use in the powertrain of a mobile vehicle, such as a heavy goods vehicle, an agricultural vehicle, a public transport vehicle or a hybrid vehicle. Background Art

[0002] Internal combustion engines do not produce constant torque and exhibit non-cyclic irregularities caused by continuous explosions in their cylinders. This leads to undesirable vibration effects on the gearbox and / or clutch, which must be reduced by equipping the vehicle transmission with a dual mass flywheel or a torque limiter.

[0003] Each torsional vibration damper comprises a primary flywheel and a secondary flywheel, which can move relative to each other around an axis of rotation, for example by means of interposed plain bearings or ball bearings, in particular plain bearings or ball bearings tightly mounted between the primary and secondary hubs of the flywheels. In addition, housed between the primary and secondary flywheels are springs for allowing relative offset between these flywheels. Generally speaking, these springs are immersed in grease and are compressed at an angle by damping spokes connected to the secondary flywheel. They are pressed against a stamped portion of the primary flywheel on one side and against a stamped portion of the primary cover or a pre-cut window in the secondary spoke on the other side.

[0004] DE102016223276 describes such a plain bearing and an end stop for a spring of a damper. However, it has been noted that current assembly lines for dampers with rolling bearings are not suitable for dampers with plain bearings, in particular axial or flange bearings, because these bearings can fall out during handling when the operator turns the main flywheel over 180 degrees. In addition to the end stop of the cover, there is also a need to improve the end stop of the spring of the existing main element.

[0005] To this end, the spring housing can be milled or machined in the main element, its unmilled end wall forming the end stop of the spring, as disclosed in FR 1 760 001. However, the geometries are complex, varied and require a long time to define by milling, vary according to the requirements of the spring, require a large number of expensive tools and have a small margin for error.

[0006] As disclosed in US5980387, a large number of end stops can alternatively be added, which are assembled vertically and fixed by riveting inside the spring housing formed by casting or pressing of the main element. In addition to the fact that such riveting is complex and cumbersome, there is also the risk of grease leakage. One and the same end stop can vary depending on the nature, size and number of springs to be considered, requiring significant variations in size and shape to be taken into account. This leads to huge costs, wear and losses, and also introduces obstacles to the standardization of the end stop manufacturing process. Summary of the invention

[0007] The invention aims to reduce the loss of material, the number of components and the steps for mounting such a damper, while limiting the differences in components for the same detent range of various springs. A particular object of the invention is to provide a simple, effective and economical solution to this problem.

[0008] To this end, according to a first aspect, the present invention provides a damping flywheel for a mobile vehicle, comprising:

[0009] - a central hub, the material continuation of which forms the central plate,

[0010] - a circular cavity with axis X, located outside the central plate of material, inside which at least: two curved damping springs, and

[0011] An end stop blade is positioned against an adjacent end of the spring, the at least one end stop blade being partially received within the interior of the center plate and fixedly attached to the center plate.

[0012] "End stop blade" means at least one thin piece that acts as an end stop for the spring and is attached inside the central hub of the flywheel, replacing the stamped geometry of the main flywheel or the riveted geometry of the main flywheel bottom. The blade reduces mechanical stress. Compared to the current state of the art main flywheels with riveted end stops, the blade has an increased ability to transmit torque; for example, it can apply high torques of more than 280 Newton meters.

[0013] "End stop blade" also means a cantilevered additional member housed inside the central hub and extending into the circular cavity. By radially continuing its material, the central hub of the flywheel is adapted to the form of a central plate of material for housing and fixing the blades. By fixing the blades inside the central hub, preferably as close as possible to the axis of rotation, it is no longer necessary to drill holes in the bottom of the flywheel cavity. This limits the amount of grease that escapes. The end stop blade is also mounted so that it can be adjusted and adjusted before or while installing the spring.

[0014] This ultimately reduces costs, the number of parts and the number of installation steps. The circular cavity presents a uniform surface and no longer requires complex extrusions to accommodate each spring. The housing of two adjacent springs is now defined by an end stop blade. It is possible to have wider tolerances, greater error margins and correction space for angularly fixing the two ends of the spring and keeping it inside the flywheel. The thickness of the adjacent parts (spokes, covers) can be reduced so that they become simple metal sheets. This limits the volume and weight of the flywheel.

[0015] Such a damped flywheel may have one or another of the features described below, which may be combined with each other or independent of each other:

[0016] - said at least one end stop blade may be made of at least one sheet metal. The thickness of this sheet may be less than or equal to half the thickness of the central plate;

[0017] - at least one end stop blade may be a single-layer blade. On the contrary, the at least one end stop blade may be a multi-layer blade, that is to say consisting of an axial stack of several layers assembled to one another, for example by gluing or by welding or by attached fixing means, in particular by riveting;

[0018] For example, there are three to ten assembly layers;

[0019] - at least one end stop blade may have a radial extension, that is to say an oblong shape. The radial extension of the end stop blade may be greater than or equal to 45% of the radial extent of the central plate, preferably greater than or equal to 1.4 times the radial extent of the circular cavity;

[0020] - The at least one end stop blade may be polygonal, trapezoidal, circular or spiral in shape. The end stop blade may have a sinusoidal shape, e.g. Figure 8 The end stop blade may be in the form of a key, with the head forming the end stop of the spring. A blade of the same shape may have different thicknesses, constituting a predetermined variable thickness range;

[0021] - at least one end stop blade may have a frustoconical shape. Said at least one end stop blade may have a symmetrical shape, the axis of symmetry S being perpendicular to the axis X of the cavity;

[0022] In a particular embodiment of the invention, the damping flywheel may comprise a series of end stop blades, preferably two, distributed uniformly or angularly around the axis X, preferably in pairs.

[0023] - the damped flywheel may comprise at least one pair of end stop blades. For each pair, the two end stop blades may be positioned radially opposite each other around the axis of rotation. In particular, the two blades share a common symmetry axis S;

[0024] - In a particular embodiment of the invention, the at least one end stop blade may be held inside a recess formed in the center plate. The end stop blade and the recess have complementary shapes. At least one recess in the center plate may extend radially from the outer diameter of the center plate. The recess may extend radially to a first end stop blade fixing mounting circle, which is used to fix to the center plate. This minimizes the amount of grease that escapes. The recess in the center plate may have a radial edge. Thus, the outer part of the recess radially enters the circular cavity;

[0025] - The at least one end stop blade may be fixedly attached to the central panel by fixing means.

[0026] - In one embodiment, at least some of the fixing means for fixing the end stop blades are arranged as close as possible to the axis of rotation, preferably starting from the inner diameter of the recess.

[0027] For example, the fixing means are received in mounting holes in the end stop blades. In particular, they are attached with fixing means received in mounting holes in the center plate, or fixing means are integrally formed from the material of the center plate, for example in the form of studs.

[0028] By way of example, they include a material retainer formed by a radially inner edge of the recess;

[0029] - in a particular embodiment, at least some of the fixing means for fixing the end stop blades can be produced by gluing or by welding or using any other fixing material;

[0030] - in a particular embodiment, at least some of the fixing means for fixing the end stop blades can be formed integrally from the material of the edge of the corresponding recess;

[0031] - By way of example, the radial edge of the recess may be in the form of an undercut in order to radially retain the end stop blade, in particular by preventing any axial movement in the direction of the cavity. This geometry makes it possible to optimize the placement of the blade in its recess in order to reduce the shear forces when the spring is compressed and the distribution of tangential forces between the recess and the blade profile;

[0032] In one embodiment of the invention, at least some of the fixing means for fixing the end stop blades may comprise one or more axial retaining elements for axially retaining said end stop blades. The axial retaining elements may be formed partly by the radial edge of the recess, for example in the form of at least one material retainer. The recess may comprise at least three material retainers, which are formed locally at certain points on the radial edge of the recess.

[0033] - each axial retaining element is, for example, formed integrally from the material of the recess, such as a projection or a discontinuous cold-worked point of material formed integrally from the recess. The material retainer can be said to be a cold-worked point configured to act on the blade segment by compression. The material retainer can be realized by twisting the material, for example, in order to form a bump or a bead of material;

[0034] - an axial material retainer may be formed by each edge of the recess;

[0035] - in one embodiment, at least some of the fixing means for fixing the end stop blades are arranged as far away from the axis of rotation as possible, preferably away from the outer diameter of the recess, or in other words away from where the recess opens into the circular cavity;

[0036] - in a particular embodiment, at least some of the fixing means for fixing the end stop blade are produced in the center of the blade body;

[0037] - the end stop blade may be provided with a single mounting hole or, as an alternative, with a plurality of holes, preferably two, located radially on the same level. To complement this, the recess may be provided with a single mounting hole or, as an alternative, with a plurality of holes, preferably two, located radially on the same level and intended to be axially aligned with one or more holes of the corresponding blade. These mounting holes are through holes, for example with an oblong or circular shape or a combination of both, so as to allow mounting and connection without radial, angular or axial play of the blade in its recess;

[0038] - In another specific embodiment, the end stop blade can be solid, that is to say without mounting holes. The recess can be solid, without mounting holes. Leakage is avoided;

[0039] - in a particular embodiment, at least some of the fixing means for fixing the end stop blades are realized by cooperating shapes, for example formed as one or more studs protruding from a recess and passing through said corresponding end stop blade;

[0040] - in another particular embodiment, at least some of the fixing means for fixing the end stop blades are produced as one or more attachment parts, such as spacers, pins or fixing rivets, which are housed, for example, in mounting holes belonging respectively to the end stop blades and to the corresponding recesses. In this way, during the step of fixing the blades, it is possible to ensure a precise alignment of the parts and the best possible contact between the blades and the bottom of the recesses;

[0041] - in a particular embodiment, said at least one end stop blade can be inserted into said recess with play, so that it can initially be fitted into the recess without any pressure or stress;

[0042] - in a particular embodiment, the recess can be designed to exert a discontinuous radial preload on the end stop blade when the end stop blade is inserted into the recess or when the end stop blade is mounted into the recess together with the fixing device. Thus, the end stop blade can be clamped, in particular starting from a side edge of the recess, preferably starting from the opening of the recess;

[0043] - In a particular embodiment, the circular cavity may include additional stop marks for accommodating the adjacent end of the damping spring. The stop marks may be angularly distributed so that the adjacent end of the spring is centered and partially stopped. The stop marks of the circular cavity are generally concave stop receiving portions designed to improve the angular stop of the adjacent end of the spring;

[0044] - in one embodiment of the invention, the end stop blades may comprise an opening angle α1 ranging from 110 to 195 degrees, preferably on each side edge of the end stop blades, which is designed to accommodate the ends of the springs; i.e. each end stop blade has a total of two opening angles of equal size, so that the spring reaction force on both sides of the end stop blade is the same;

[0045] - This opening angle is adapted to the installation diameter of the spring end. The smaller the spring installation diameter, the smaller the opening angle α1;

[0046] - For example, the opening angle α1 may be set to an angle of about 110 degrees by default, and when installing the spring, the operator will adjust the opening angle by planing, grinding, lapping, etc. or any other means of removing material to make the opening edge of the end stop head smoother;

[0047] - In a particular embodiment of the invention, said at least one end stop blade may comprise

[0048] - a retaining body housed inside the central panel, and

[0049] - an end stop head which originates from the continuation of the retaining body, which end stop head has a flared shape and is adapted to the spring;

[0050] - The end stop head is solid, without material removal (no holes and material branches);

[0051] - the end stop head comprises a radial extension which may extend from the inner diameter of the circular cavity to the outer diameter of the circular cavity;

[0052] - the retaining body comprises a radial extension which is greater than 1.2 times, in particular greater than or equal to 1.5 times, the radial extension of the end stop head;

[0053] The end stop head can define an opening angle α1 together with the holding body.

[0054] - The opening angle of the end stop blades ranges from 110 to 195 degrees to improve cooperation with the ends of the springs. The end stop heads are thus adjusted according to the requirements of the adjacent ends of the springs in order to accommodate them inside the flywheel. The opening angle is defined for the edge faces or flared edges of the heads to improve their cooperation and fixing properties.

[0055] - By way of example, the end stop head together with the retaining body defines an opening angle ranging from 130 to 160 degrees. The end stop blade thus comprises a constriction of material so as to jointly define the end stop head and the retaining body, both of which are of flared shape;

[0056] - in one embodiment of the invention, the central hub may comprise at least one clearance space, preferably machined, for accommodating a locking bushing, preferably an axial locking bushing;

[0057] - the clearance space may be formed along the central hub, or in other words, have an axial extent;

[0058] - the locking bushing can be housed along the central hub, or in other words, fixed axially;

[0059] The so-called locking bushing is a radially or axially extending plain bearing, or a hollow cylindrical component, for example a metal washer type component;

[0060] According to a second aspect, the present invention also relates to a damped flywheel for a mobile vehicle, comprising:

[0061] - a central hub, the material continuation of which forms the central plate,

[0062] - a single circular cavity with axis X, outside the central plate of material, inside which are housed: at least two curved damping springs,

[0063] Therein, the central hub comprises at least one machined clearance space for accommodating a locking bushing, preferably an axial stop bushing, along the central hub.

[0064] According to this aspect, a damped flywheel has been designed that has a machined center hub with a specific clearance space system for holding an axial bushing. Producing this clearance space to fit any type of bushing means that the bushing will not fall out when the operator installs and operates the damped flywheel. This allows the same assembly line to be used to produce dampers with rolling and sliding bearings.

[0065] This aspect of the invention may have one or other of the features described below, in combination with each other or independently of each other:

[0066] - The machined clearance space may be a groove designed to retain the bushing;

[0067] - in a particular embodiment, the damping flywheel, in particular the central hub, can be multi-part and is formed by at least a first part forming a central plate and a second part for housing at least one locking bushing;

[0068] - Preferably, the first part of the multi-part central hub may comprise a circular cavity for accommodating the spring and a centering flange for the second part. The centering flange is used to accommodate an axial locking bushing and a radial locking bushing for centering the second part;

[0069] - As an alternative, the second part of the multi-part central hub may comprise a circular cavity for accommodating the spring and a centering flange for the first part. The centering flange is used to accommodate the axial locking bushing and the radial locking bushing for centering the first part;

[0070] - For example, a multi-part central hub may consist of three parts that are assembled to each other;

[0071] - Advantageously, the central hub may comprise two clearance spaces machined from recesses in the centering collar in order to retain an axial locking bushing or a radial locking bushing, respectively. Each clearance space may be adjoined by at least one material shoulder;

[0072] - the first part may form a primary flywheel connectable to the drive shaft (at the motor, called input element). - the second part may form a secondary flywheel connectable to the driven shaft (at the housing part, called output element);

[0073] According to a third aspect, the invention also relates to an end stop blade for a spring of a damped flywheel, the blade having a flared frustoconical shape in the form of an end stop head for angularly abutting against an adjacent end of a spring of a damped flywheel. The end stop blade comprises a radial extension in the form of a retaining body for attachment to a central hub of the damped flywheel, the extension preferably being greater than or equal to 1.5 times the radial extension of said end stop head.

[0074] According to a fourth aspect, the invention also relates to a central hub for a damped flywheel, the continuation of the material of the central hub forming a central plate of material, the outside of the central plate being bounded by a single circular cavity of the axis of rotation X, wherein the central plate comprises a series of recesses for accommodating a series of end stop blades.

[0075] According to a fifth aspect, as a subject, the present invention also proposes a kit for assembling a damped flywheel, comprising at least:

[0076] - damping springs with an initial straight or curved shape;

[0077] - a series of end stop blades according to the second aspect of the invention;

[0078] - a central hub of a damped flywheel according to the third aspect of the invention;

[0079] The assembly kit may further comprise an axial retaining element for axially retaining the end stop blade.

[0080] The assembly kit may also include, inside the central hub, a single circular cavity of axis X, bounding the exterior of the central plate of material, the spring being housed inside the circular cavity.

[0081] The second, third, fourth and fifth aspects of the invention may reintroduce all or some of the features described above, particularly in the first aspect of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] The invention will be better understood and further objects, details, features and advantages of the invention will become more apparent from the following description of specific embodiments of the invention, which description is given by way of non-limiting illustration only and refers to the accompanying drawings:

[0083] - Figure 1 is a perspective overview of a power train comprising at least one damped flywheel according to the invention, in this case a dual mass flywheel;

[0084] - Figure 2 is an axial cross-sectional view of a dual mass flywheel according to a first embodiment;

[0085] - Figure 3 yes Figure 2 A radial cross-section of the damped flywheel in FIG.

[0086] - Figure 4 is fixed according to Figure 2 Detailed view of the end stop blades inside the center hub;

[0087] - Figure 5 is based on Figure 2 A view of the end stop blade itself;

[0088] - Figure 6 Is based on Figure 2 A view of the center hub of the end stop blade recess;

[0089] - Figure 7 is similar to Figure 2 A view of the cover of a dual mass flywheel;

[0090] - Figure 8 is a radial cross-sectional view of a damped flywheel according to a second embodiment;

[0091] - Fig. 9 Is based on Figure 8 A view of the center hub itself of the end stop blade recess;

[0092] - Fig.10 yes Figure 8 A perspective view of a damped flywheel with end stop vanes;

[0093] - Fig.11 is a radial cross-sectional view of a damped flywheel according to a third embodiment;

[0094] - Fig.12 Is based on Fig.11 A view of the center hub itself of the end stop blade recess;

[0095] - Fig.13 is a radial cross-sectional view of a damped flywheel according to a fourth embodiment;

[0096] - Fig.14 Is based on Fig.13 A view of the center hub itself of the end stop blade recess;

[0097] - Fig.15 is based on Fig.13 A view of the end stop blade itself;

[0098] - Fig.16 is similar to Fig.11 Variations of the multi-layer end stop blades themselves;

[0099] - Fig.17 is an axial cross-sectional view of a hub of a dual mass flywheel, such as one from the first, second, third or fourth embodiment of the invention;

[0100] - Fig.18 is based on Fig.17 Detailed view of the hub of the dual-mass flywheel;

[0101] - Fig.19 yes Fig.17 An example of a dual mass flywheel with a multi-component center hub;

[0102] - Fig. 20 yes Fig.17 Another example of a dual mass flywheel with an integral central hub. DETAILED DESCRIPTION

[0103] In the following description and claims, to facilitate understanding, the following terminology will be used in a non-limiting manner:

[0104] - "mobile vehicle" is understood to mean motor vehicles, passenger cars, but also industrial vehicles, in particular heavy goods vehicles, public transport vehicles or agricultural vehicles, but also any transport vehicle capable of transporting living beings and / or objects from one point to another;

[0105] - “Front” or “rear” are understood to mean in a direction relative to the axial orientation determined by the main axis of rotation X of the transmission of the moving vehicle; “inner / internal” or “outer / external” are understood to mean in a radial direction relative to the axis X and orthogonal to the axial orientation.

[0106] In the following description and claims, ordinal numbers may be applied to certain elements, such as the first or second fixing element / member, the first or second shaft, the first or second end stop blade, etc. This is done only to distinguish and designate similar but not identical elements. Ordinal numbers do not imply that one element takes precedence over another, and such designations may be readily interchanged without departing from the scope of this specification.

[0107] In a first embodiment, at least one damped flywheel 2, also called torsion damper, of a powertrain 1 according to the invention is shown, which comprises at least an internal combustion engine A, a gearbox B and a clutch 7, for example, located between the gearbox B and the internal combustion engine A. The clutch 7 can be of wet or dry type.

[0108] The torsional damper 2 comprises a central hub intended to be connected to an engine shaft A (referred to as drive shaft A1 ) or a gearbox shaft B (referred to as driven shaft B1 ). The torsional damper 2 is intended to be positioned at the transmission of a motor vehicle.

[0109] Figure 1 , Figure 2 and Figures 17 to 20 A detail of a dual mass flywheel 2 is shown. Within the meaning of the invention, the torsion damper 2 may have a plurality of components, in particular at its central hub 20, comprising a first element 210, also called primary flywheel, and a second element 220, also called secondary flywheel, which is movably mounted relative to the first element 210 about a central axis of rotation X (in Figure 1 and 17 20). The first element 210 constitutes a primary flywheel with a primary hub 215, and the second element 220 constitutes a secondary flywheel, each having a secondary hub 225. The rotation between the first element 210 and the second element 220 is performed, for example, via a rolling bearing or a sliding bearing constituted by bushings 8, 9. In this case, the primary hub 215 and the secondary hub 225 can constitute the central hub 20 according to the invention.

[0110] The torsional damper 1 also includes an elastic element positioned between the first component or element 210 and the second component or element 220 and configured to damp non-cyclic irregularities of rotation generated by the engine of the motor vehicle. The elastic element includes, for example, one or more helical springs 4. The central hub 20 may have a plurality of components consisting of components 210, 200.

[0111] In the following description, a torsional damper 1 comprising two helical springs 4 will be considered, each having an end 40 terminating in the form of a turn. In this case, there are two springs 4 arranged in parallel, but the invention is also applicable to a torsional damper 1 comprising a single spring or more than two springs. The invention can be applied to a torsional damper comprising a straight spring or springs arranged in series or a combination of the above features.

[0112] The damped flywheel 2, and in particular the first element 210, is noteworthy in that it comprises a central hub 20 having a radial extent p0 greater than the radial extent of the circular cavity 400. The radial extent of the cavity is defined between the inner and outer diameters of the circular cavity.

[0113] Furthermore, the material continuation p0 of the central hub 20 forms a central plate 21 of outer diameter Dp1 designed to form a portion of an end stop as close as possible to the spring 4 .

[0114] The torsional damper 2 may also include a pendulum device (not shown) configured to improve filtering of non-cyclic irregularities of rotation. In addition, the first element 210 includes a centering flange 291 for centering the second element 220. The centering flange 291 is used to accommodate the axial locking bushing 8 and the radial locking bushing 9 for centering the second element 220.

[0115] The central hub 20 is notable in that it comprises at least one clearance space 28, 29 for accommodating the locking bushings 8, 9 and which is preferably machined along said central hub. Figures 17 to 20 As shown, two clearance spaces 28, 29 are machined from a recess 292 in the centering flange. Each clearance space 28, 29 adjoins at least one material shoulder 280, 290. Thus, the clearance space 28 holds the axial locking bushing 8, in this case via the material shoulder 280. The clearance space 29 holds the radial locking bushing 9, in this case via the material shoulder 290.

[0116] like Fig. 20As shown, the torsional damper 1 may also comprise a hysteresis system 30. In this case, the hysteresis system is a stack of friction washers 301, 302 between the first and second elements 210, 220, which form the first and second inertial masses, respectively.

[0117] Furthermore, the springs 4 are, for example, curved springs, which are arranged together in a circular cavity 400 of the first element 210, over 360 degrees in a housing 400a provided for this purpose. The circular cavity 400 is obtained using a single tool, thereby simplifying the milling step. The housings 400a of the circular cavity 400 are delimited from each other by the addition of at least one end stop blade 5 attached to the central hub 20 and against which the adjacent ends 40 of the springs 4 elastically abut. It must be noted here that the circular cavity 400 is a single circular cavity and can contain a pool of grease to keep the springs 4 lubricated.

[0118] Furthermore, the torsional damper 1 may comprise a spoke 14 configured to bear against and compress the spring 4 when the torsional damper 1 is in use. Alternatively, the spoke 14 may be positioned between two series of springs (in the case of a torsional damper with multi-stage springs), the first series of springs being positioned between the first element 210 and the spoke 14, and the second series of springs being positioned between the spoke 14 and the second element 210 (or more generally, an element fixed to the second element 210, such as a guide washer).

[0119] Furthermore, the torsion damper 2 comprises half stops or end stops, called lower end stops and upper end stops, formed at each end 40 of the spring so that the spring can be compressed, for example, by a spoke. All these aforementioned end stops ensure that the bearing forces of the spring 4 are distributed inside the torsion damper and prevent any imbalances that could damage the spring 4 when the torsion damper transmits high torques. For example, the end stops of the upper part of the damper are formed by a series of stamped parts 35' in the cover 3.

[0120] The invention is remarkable in that the end stop of the lower part of the damper is formed by a series of end stop blades cantilevered from the central hub 21. The number of end stop blades is the same as the number of springs, in this case two, distributed in the form of a pair of blades. The two end stop blades 5 of a pair are preferably angularly spaced from each other around the axis of rotation so that they are radially opposite to each other. They can therefore share the same axis S perpendicular to the axis X. Each end stop blade 5 is attached and partially housed inside the central plate 21 at a portion of the radial extension l2 of the retaining body 52 that defines the end stop blade. The retaining body 52 of the blade is fixedly housed in the central plate 21, in a specific housing portion of the central plate 21 formed for this purpose, called the recess 25.

[0121] By "recess" is meant a void whose shape is similar to the end stop blade 5 so that they are firmly held together. Their shapes complement each other and are predetermined at the time of manufacture.

[0122] The recesses 25 are formed radially outside the center plate 21 so as to open into the circular cavity 400. In the example shown, each recess extends radially from an inner diameter to an outer diameter. The inner diameter of the recess is defined by the inner wall 254. The outer diameter of the recess is defined by its opening, which opens into the circular cavity.

[0123] The recess is defined angularly between the two radial edges 250. Each end stop blade 5 is also partially housed inside the circular cavity.

[0124] The end stop blade 5 does not cooperate with the bottom of the circular cavity, but is suspended therefrom. The end stop blade defines a certain amount of axial play J to maintain the installation freedom of the blade and the spring to be housed in the circular cavity.

[0125] The two springs are respectively located on both sides of the end stop blade 5 and abut against each other at the outer head portion, which is in a flared shape and is called an end stop head portion 51 adapted to the springs.

[0126] Each end stop head originates from the continuation of the retaining body. The entire body may form a frustoconical or sinusoidal shape, e.g. Figure 8 The retaining body 52 defines a radial extension l2 which is 1.2 times the radial extension l1 of the end stop head. The radial extension l1 of the end stop head 51 extends from the inner diameter of the circular cavity and, in the example shown, may extend to the outer diameter of the circular cavity. It should be noted that l1+l2=l0.

[0127] The end 40, referred to as the end turn of the helical spring 4, comprises a first portion configured to abut against one end stop blade 5 and a second portion configured to abut against a second half stop 35' formed on the cover 3. Thus, during operation of the torsional damper 2, a relative rotation of the second element 220 with respect to the first element 210 causes the spring 4 to be compressed between the spoke 14, the end stop blade 5 and the end stop of the cover.

[0128] Figure 6 Such a cover 3 is shown, which is intended to be fixed on the first element 210 in such a way as to at least partially cover the spring 4 and the end stop blades 5 between which the spring is accommodated.

[0129] The housing portion 400 a , in particular of the same size, is then defined in the shape of a portion of a torus and extends in a peripheral region close to the first element 210 .

[0130] A channel 44 may also be arranged in the receiving portion 400a for radially holding the helical spring in place in the receiving portion 400a. The channel 44 is particularly positioned on the (radially) outer portion of the circular cavity, which is also referred to as the annular skirt 209. In addition, the annular skirt 209 may form an annular ring 207, thereby forming a target with an axial orientation. The annular ring 207 may define the reading area of ​​the sensor. It extends axially 360 degrees around the axis X from the outer periphery of the skirt 209, which in this case is the radial outer wall of the skirt. The annular ring 207 includes a plurality of windows, which are separated from each other by fingers or arms extending in an axial direction parallel to the axis X.

[0131] Furthermore, the cover can be produced by machining or pressing, from steel or casting. The cover 3 is fixed, for example, by a welding process using crimping. In order to simplify the end-to-end mechanical assembly of the cover 3 on the cylindrical skirt 209, positioning means 29', 39' of complementary shapes (concave-convex shapes or convex-concave shapes) are formed by the inner end edges of the cylindrical skirt 8 and the outer periphery of the cover 3, respectively, so as to axially position the cover relative to the skirt. These positioning means 29', 39' are positioned axially facing each other, that is, one after another, and must have the same and limited number of positioning means. There can be two ( Figure 6 and Figures 9 to 14 ), or alternatively, there can be three ( Figure 7 ).

[0132] Each positioning device 29' formed in the damping flywheel 2 has a circular profile, such as a half-moon shape or a hollow semi-cylindrical shape. In addition, each end stop blade 5 can be positioned facing the positioning device 29' of the cover.

[0133] Furthermore, the spokes 14 can be fixed to the second element 220, in particular by means of fixing means 140, in this case forming a series of rivets. This first series of rivets is housed in mounting holes 27 of axis V of the central hub 20, in this case the central plate 21 or of the first element 110. The mounting holes 27 are formed as through holes, that is to say, they extend through the entire axial thickness e0 of the central plate 21 and are remote from the grease pool in the circular cavity 400, thereby avoiding any risk of leakage.

[0134] like Figure 1 , Figure 6 , Fig. 9 and Fig.10 As shown, the rivets 140 that secure the spokes 14 are radially positioned on the same level, thereby defining a first mounting circle V1 on the central plate 21 .

[0135] Each end stop blade 5 and the corresponding recess 25 will now be described in more detail.

[0136] The end stop blade 5 has a radial extension l0, called length, which is much greater than its width or radial extent l0' of the recess 25. This shape is therefore called oblong. The radial extension l0 is defined from the inner end 502 to the outer end 501.

[0137] The outer end 501 defines a raised edge forming a flared end stop head of frustoconical shape and an angular extent that can be adapted to any type of adjacent curved turns of the spring or the end 40 of the spring. Each end stop blade extends radially inside the central plate 21 with a radial extension l0. The radial extension l0 is greater than 1.4 times the radial extent of the circular cavity.

[0138] The end stop blade 5 may be single-layered, cut from a relatively thin sheet of metal having a thickness e0 which remains substantially the same along the end stop blade. The thickness e0 of the end stop blade is strictly less than or equal to half the thickness e2 of the central plate.

[0139] In one variation, Fig.16 A multilayer end stop blade 5 is shown, which consists of an axial stack of a plurality of layers 500 assembled on top of one another, in this case four layers.

[0140] In the example shown, rivets passing through the mounting holes 57 are used to assemble the layers 500. However, the layers 500 may also be preassembled by gluing or welding.

[0141] Each recess 25 has a shape complementary to that of the end stop blade 5 so as to retain the end stop blade 5. This complementary shape may be a convex-concave shape or a concave-convex shape so as to at least partially securely accommodate the end stop blade 5 in the corresponding recess 25. In addition, the recess 25 is defined between two opposite radial edges 250 and an inner wall 254.

[0142] The shape of the end stop blade 5 and therefore of the recess 25 may be symmetrical, defined by an axis of symmetry S. In this way, the opposing reaction forces exerted by the spring and the side edges of the recess are evenly distributed. The fillets 255 of the recess of complementary shape cooperate with the fillets 525 for attaching the end stop blade 5. The outside of the recess radially enters the circular cavity, forming a radially outer opening.

[0143] The end stop head 51 has two opposite side edge faces 510, 520 with flat abutment surfaces capable of withstanding very high torques exceeding 250 Newton meters in normal operation. The inner end 502 defines a specific edge, in this case a plane edge provided with an attachment fillet 525 formed at the radially inner corner of the end stop blade 5. This specific edge of the inner end 502, in particular its attachment fillet 525, is designed to be received in the recess 25.

[0144] The end stop blades include an angle α1 on each lateral edge designed to accommodate the ends of the springs. The complementary recesses include an angle α1' approximately equal to the angle α1. These angles α1, α1' reduce stress and increase torque capacity. Figure 6 , Fig. 9 , Fig.12 and Fig.14 These empty recesses 25 are shown for the various centre plates 21 (before the blades are mounted).

[0145] In addition, each end stop blade 5 can be inserted into the recess with play. The play is a radial play that can be formed by the inner wall 254 to bring the end stop blade to the outside of the recess, thereby positioning the blade inside the recess for final assembly.

[0146] The various fixing means 6, 26, 7, 57, 57' for fixing the end stop blades will now be described in more detail.

[0147] Furthermore, the recess 25 comprises various fixing means 6, 26, 7, 57, 57' for maintaining the final position of the end stop blade 5. The fixing means are located away from the grease pool in the circular cavity 400 to avoid any risk of leakage.

[0148] In particular, at least some of the end stop blade fixtures are arranged as close as possible to the rotation axis, preferably starting from the inner diameter of the recess, for example positioned as close as possible to the inner wall 254 of the recess.

[0149] Furthermore, the recess 25 is dimensioned to apply a radial preload to the end stop blade when it is inserted into the recess or when it is mounted using the additional central fixing device 7 .

[0150] In the example shown, the blade fixing means are formed in the recess and are arranged such that:

[0151] - as close as possible to the axis of rotation, for example on the inner wall 254 of the recess; or in other words, at the junction where the shape of the retaining body meets the shape of the end stop head; and / or

[0152] - as far away from the axis of rotation as possible, for example via a portion of the side edge 250 defining the opening of the recess, in the form of a clamping contraction; and / or

[0153] In the central region of the side edges of the holding body 52 .

[0154] Furthermore, the blade fixing device comprises axial retaining elements. To supplement this, these axial retaining elements are formed as material retainers of the recesses.

[0155] Figure 4 An example of a material retainer is shown, for example by twisting the material to form a bead that holds the blade axially inside the recess. The axial retaining element may be formed in part by each radial edge of the recess, for example in the form of at least one material retainer. In this way, these side edges secure the end stop blade in both clockwise and counterclockwise rotation directions around the axis of rotation.

[0156] Furthermore, the end stop blade may be fixed in the recess by a central fixing means 7 which passes through a first mounting hole 57 in the end stop blade.

[0157] In a first embodiment, the central fixing means 7 for the blades are attached in the form of a series of rivets, through-hole bolts or pins which also pass through the second mounting holes 257 in the recess 25. The mounting holes 257 are preferably circular. The mounting holes 57, 257 are coaxial with the axis M. They are through holes extending through the entire thickness e0 of the blade and the entire thickness e2 of the plate, respectively. The number of mounting holes 57, 257 (for each end stop blade 5 and each recess 25) is two, radially positioned on the same level. These mounting holes 57, 257 are located away from the grease pool in the circular cavity 400 and, in this case, as close as possible to the radial wall 254 of the recess. This series of rivets 7 defines a second mounting circle M1 at the central plate 21. For example, the mounting circles V1 and M2 are coincident.

[0158] Each blade and recess may have two holes 57, 257, which are arranged radially on the same level, or, in a variant not shown, one hole. The hole 57 may have different profiles.

[0159] The first embodiment of the Figure 5 An example of a circular mounting hole 57 is shown.

[0160] Fig.16 An oblong mounting hole 57 is shown. In another embodiment not shown, the central fixing means 7 for fixing the blade may originate from a recess, for example being formed by one or more studs protruding from the recess.

[0161] Furthermore, the fixing means are formed partly by the cooperation between the shapes of the blade 5 and the recess 25. In the first embodiment, the end stop blade 5 and the complementary recess 25 have a substantially rectangular or trapezoidal shape. Figure 6 A radial wall 254 is shown which is substantially perpendicular to the side edge. In this case, the opening angle α1, α1' is equal to approximately 350 degrees.

[0162] In other embodiments similar to the first embodiment, by contrast, the radial edge 250 of the recess 25 and the edge surface of the end stop blade are shown to form an undercut 255, which alternately presents a concave and convex shape, presenting a Figure 8 Or a heptagonal shape, or an hourglass shape. A polygonal shape can be formed with a smaller or greater number of bearing sides (pentagons, hexagons, octagons, etc.) that bear against the spring and the edge of the recess.

[0163] In this case, each end stop blade 5 then comprises two concave narrowings of material, delimiting both the end stop head and the retaining body, each narrowing of material being defined by a small opening angle α1 , α1 ′, in this case approximately equal to 330 degrees.

[0164] Furthermore, the fillet 525 of the end stop blade is conical, defining a retention angle α2. Similarly, the inner wall 254 of the recess, and in particular the fillet 255, may have a conical cross-sectional shape, defining a retention angle α2' approximately equal to the retention angle α2 of the blade.

[0165] Fig. 9 , Fig.12 and Fig.14 Such an undercut 255 of the recess 25 is shown in detail, which prevents any radial movement of the end stop blade in the direction of the circular cavity. Each undercut 255 forms a calibration angle α3' for angularly and radially stopping the retaining body.

[0166] In a second embodiment, the housing portion 400a can be predefined. The circular cavity 400 then comprises an additional marked stop area, called stop mark 45, which is visible to the operator and partially accommodates the adjacent end 40 of the spring 4 so as to correctly position the spring 4 simultaneously with the blade. Each recess has two stop marks, which are angularly distributed on each side of the end stop blade 5. Each marked stop area is produced inside the circular cavity 400, preferably by machining or stamping.

[0167] In a third embodiment similar to the first embodiment, in contrast, no stop marks are shown, so that the circular cavity 400 is a continuous plane over 360 degrees.

[0168] On the other hand, in a fourth embodiment similar to the first embodiment, the blade fixing means are realized by material retainers 57' produced by cold working and are referred to as cold working points. Thus, the mounting holes in the blade or in the recess are omitted. There are fewer mounting steps, less material loss, and any spilled grease that enters the groove is contained.

[0169] These material retainers 57', in this case three of them, are formed on each edge 250, 254 of the recess. Figure 13 to Figure 14 As shown, they act by compression on a section of the end stop blades.

[0170] In an embodiment not shown, these material retainers 57 ′ can be replaced by spots of welding material previously applied to the interior of the recess.

[0171] Although the invention has been described in connection with a single specific embodiment, it is obvious that the invention is by no means limited thereto and that the invention comprises all technical equivalents of the means described as well as combinations thereof, as long as they fall within the scope of the invention.

[0172] However, the invention is not limited to the devices and configurations described and shown here, and also extends to any equivalent devices or configurations and any technically operable combination of these devices. In particular, the shapes of the blades and recesses can be modified without departing from the invention, as long as these components ultimately have the same functions as the components described herein. In the claims, any reference numerals between brackets shall not be interpreted as limiting the claim.

Claims

1. A damping flywheel (2) for a mobile vehicle, comprising: - a central hub (20), the continuation of the material of the central hub (20) forming a central plate (21), - a circular cavity (400) with an axis (X), located outside the central plate (21), inside which at least: two curved damping springs (4), and an end stop blade (5) positioned against the adjacent end (40) of the spring (4), at least one of the end stop blades being partially housed inside the central plate and fixedly attached to the central plate (21).

2. The damping flywheel (2) according to claim 1, wherein: The end stop blade (5) is made of at least one metal plate in an oblong shape, such as - the thickness (e0) of the end stop blade is less than or equal to half the thickness (e2) of the central plate (21), and / or The radial extension (l0) of the end stop blade is greater than or equal to 45% of the radial extent (p0) of the central plate (21), preferably greater than or equal to 1.4 times the radial extent of the circular cavity (400).

3. The damping flywheel (2) according to claim 1 or 2, wherein: The damping flywheel at least comprises an end stop blade (5) consisting of an axial stack of assembled layers, and / or A pair of end stop blades (5) radially opposed about said axis (X).

4. A damped flywheel (2) according to any one of the preceding claims, wherein: The end stop blade comprises a retaining body (52) housed inside the center plate and an end stop head (51), the end stop head (51) originating from a continuation of the retaining body (51), the end stop head (51) preferably having a solid and flared shape adapted to the spring (4), preferably, the end stop head (51) together with the retaining body (52) defines an opening angle (α1) ranging from 110 degrees to 195 degrees.

5. The damping flywheel (2) according to claim 4, wherein: The end stop blade (5) includes a narrowed portion of material defining an end stop head (51) and a retaining body (52), wherein the end stop head (51) and the retaining body (52) are both flared in shape, and preferably, the end stop head (51) and the retaining body (52) together define an opening angle (α1) ranging from 130 degrees to 160 degrees.

6. The damped flywheel (2) according to claim 4 or 5, wherein: The radial extension (l1) of the end stop head (51) extends from the inner diameter to the outer diameter of the circular cavity, and / or the radial extension (l2) of the retaining body (52) is greater than or equal to 1.5 times the radial extension (l1) of the end stop head (51).

7. A damped flywheel (2) according to any one of the preceding claims, wherein: The end stop blade (5) is retained in a recess (25) having a complementary shape and formed radially from the outer diameter (Dp1) of the center plate (21).

8. The damped flywheel (2) according to claim 7, wherein: The end stop blade (5) is retained by fixing means arranged from the inner diameter of the recess, the fixing means being received in the mounting hole (57) for mounting the end stop blade (5), such fixing means being, for example: - attached (7, 57) and received in a mounting hole (27) in the central plate, or - formed integrally with the material (6, 26, 57') of the central panel, for example in the form of studs.

9. The damped flywheel (2) according to claim 7 or 8, wherein: The end stop blade (5) is retained by an axial retaining element (6), which is used to axially retain the end stop blade. The axial retaining element (6) is preferably formed integrally from the material of the recess, such as a protrusion (26) or a discontinuous cold working point (57') of the material.

10. The damped flywheel (2) according to any one of claims 7 to 9, wherein: The radial edge (250) of the recess is in the form of an undercut (255) which radially retains the end stop blade, and / or Additional stop marks (45) for the adjacent end (40) of the spring are produced inside the circular cavity (400) and are positioned angularly on each side of at least one recess (25).

11. A damped flywheel (2) according to any one of the preceding claims, wherein: The central hub (20) comprises at least one clearance space (28, 29) for receiving a locking bushing (8, 9), preferably a clearance space (28, 29) machined along the central hub.

12. The damped flywheel (2) according to claim 11, wherein: Two clearance spaces (28, 29) are machined from a recess (292) in the central hub (20) to retain an axial locking bushing (8) or a radial locking bushing (9), respectively, each clearance space (28, 29) being adjoined by at least one material shoulder (280, 290).

13. An end stop blade (5) for a damped flywheel, having a flared truncated cone shape, in the form of the end stop head (51), for angularly abutting against an adjacent end (40) of a spring (4) of the damped flywheel, the end stop blade comprising a radial extension in the form of a retaining body for attachment to a central hub of the damped flywheel, preferably greater than or equal to 1.5 times the radial extension of the end stop head.

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