FR3075293A1 - TORSION DAMPER, SAIL AND ASSOCIATED ASSEMBLY - Google Patents

Abstract

 The present invention relates to a web (11) for torsion damper (1) comprising elastic means (9), a first element (3) movable in rotation relative to a second element (5), said web (11) comprising:  - an annular central part (11a),  - An annular peripheral part (11c) comprising external fins (110) intended to be in abutment against the elastic means (9) of the torsion damper (1), the elastic means (9) being intended to be interposed between said external fins (110) and the first element (3) of the torsion damper (1),  the annular central part (11a) being intended to be fixed on the second element (5),  in which an intermediate part (11b) connects the annular central part (11a) and the annular peripheral part (11c),  said intermediate part (11b) comprising alternating openings (114) and link arms (116) between the annular central part (11a) and the annular peripheral part (11c), said link arms (116) being configured to deform elastically and allow relative rotation between the annular central part (11a) and the annular peripheral part (11c) by the elastic deformation of the intermediate part (11b).

Description

TORSION DAMPER, SAIL AND ASSOCIATED ASSEMBLY

The present invention relates to the field of torsion dampers, in particular for motor vehicles.

Explosion engines do not generate constant torque and have acyclisms caused by successive explosions in their cylinders. These acyclisms generate vibrations which are capable of being transmitted to the gearbox and thus causing particularly undesirable shocks, noise and noise. In order to reduce the undesirable effects of vibrations and improve the driving comfort of motor vehicles, it is known to equip motor vehicle transmissions with torsional dampers.

Torsion dampers generally include a primary element and a secondary element which can rotate in relation to each other about an axis of rotation. The torsion dampers also include elastic damping means arranged between the primary element and the secondary element to dampen acyclisms. In addition, certain torsion dampers, in particular the double damping flywheels, use a web coupled in rotation to the primary element or to the secondary element to interact with the elastic damping means.

Thus, especially in cases where the torsional damper is subjected to a high torque, the stresses at the level of the web can be very high, which can lead to degradation of the web.

It is therefore advisable to find a solution making it possible to avoid degradation of the web even when the torque transmitted by the torsion damper is very high and leads for example to an abutment of the elastic damping means.

To this end, the present invention relates to a veil for torsion damper comprising elastic means, a first element movable in rotation relative to a second element, said veil comprising:

- an annular central part,

an annular peripheral part comprising external fins intended to be in abutment against the elastic means of the torsion damper, the elastic means being intended to be interposed between said external fins and a first element, the annular central part being intended to be fixed to the second element, characterized in that it further comprises an intermediate part connecting the annular central part and the annular peripheral part, said intermediate part comprising an alternation of openings and connecting arms between the annular central part and the annular peripheral part, said link arms being configured to elastically deform and allow relative rotation between the annular central part and the annular peripheral part by the elastic deformation of the intermediate part.

The elastic deformation of the veil prevents its deterioration in the event of significant torque to be transmitted.

According to another aspect of the present invention, the openings have rounded corners.

Rounded corners limit mechanical stress at the openings

According to another aspect of the present invention, at least some of the openings are oblong openings whose major axis extends in a radial direction.

According to another aspect of the present invention, the annular central part comprises circular orifices intended to receive rivets for fixing to the first element.

The present invention also relates to an assembly for torsion damper comprising:

- a veil according to one of the preceding claims,

- an additional washer intended to be fixed with the veil to the first element and comprising at least one pair of stops extending axially and intended to be positioned on either side of a connecting arm of the veil so that in the state of rest of the web there is a clearance between the stops and the link arm.

According to another aspect, the clearance corresponds to a rotation of at least 0.5 degrees between the annular central part and the annular peripheral part.

The additional washer makes it possible to recover the force undergone by the veil when the veil is subjected to a torque greater than a predetermined value leading to a deformation of the upper veil until contact with the stops of the additional washer.

According to another aspect of the present invention, the play is between 0.5 and 5 degrees.

According to another aspect of the present invention, the additional washer has a rigidity greater than the web along the axis of torque transmission.

According to another aspect of the present invention, the additional washer comprises a peripheral part configured to come into contact with the annular peripheral part of the web so as to create a friction zone allowing dissipation of the mechanical energy stored by the web in the form heat when a significant torque is applied to the veil.

According to another aspect of the present invention, the web and the additional washer are made of the same material.

According to another aspect of the present invention, the material is steel.

The present invention also relates to a torsion damper comprising:

- a first element,

a second element movable in rotation relative to the first element,

- elastic means intended to be interposed between the first element and the second element to absorb acyclisms during a torque transmission,

- a veil as described above.

According to another aspect of the present invention, the torsion damper comprises:

- a first element,

a second element movable in rotation relative to the first element,

- elastic means intended to be interposed between the first element and the second element to absorb acyclisms during a torque transmission,

- an assembly as described above.

According to another aspect of the present invention, the torsional damper comprises two flywheels forming a double damped flywheel.

Other characteristics and advantages of the invention will emerge from the following description, given by way of example and without limitation, with reference to the appended drawings in which:

FIG. 1 represents a schematic view in axial section of part of a torsion damper according to an embodiment of the present invention,

FIG. 2 represents a diagram of a web according to a first embodiment of the present invention,

FIG. 3 represents a diagram of a web according to a second embodiment of the present invention,

FIGS. 4 and 5 represent two schematic views of an additional washer according to an embodiment of the present invention,

FIGS. 6 and 7 represent two schematic views of an assembly comprising a veil and an additional washer according to an embodiment of the present invention,

FIG. 8 represents a diagram of a pair of stops of an additional washer positioned around a link arm of a web according to an embodiment of the present invention,

- Figure 9 shows a sectional view of part of a torsion damper according to an embodiment of the present invention.

In all the figures, identical elements or ensuring the same function bear the same reference numbers.

The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment or that the characteristics apply only to a single embodiment. Simple features of different embodiments can also be combined or interchanged to provide other embodiments.

In the following description, the terms "first", "second", "second" ... for example "first part", "second part" are used for a simple indexing of the elements to name and differentiate close but not identical elements . This indexing does not imply priority of one element over another and one can easily interchange such names without departing from the scope of this description. This indexing does not imply an order in time either.

In the following description, the terms "axial", "radial" and "transverse" to define the orientation of the elements of the torsion damper refer to the axis of rotation X of the torsion damper and define respectively a direction parallel to the axis of rotation X, a plane comprising the axis of rotation X and a plane perpendicular to the axis of rotation X.

FIG. 1 represents a part of a torsion damper 1, for example a double damping flywheel, intended for example to be installed in a motor vehicle and comprising:

a primary element 3, for example a primary flywheel, intended for example to be coupled in rotation to an output shaft of an engine of the motor vehicle,

a secondary element 5, for example a secondary flywheel, intended for example to be coupled in rotation with a gearbox of the motor vehicle, movable in rotation relative to the primary element around an axis of rotation X

a bearing 7 to allow rotation between the primary element 3 and the secondary element 5,

- an elastic element 9, for example one or more helical spring (s) intended to be disposed between the primary element 3 and the secondary element 5 and configured to damp the acyclisms of rotation produced by the motor, the elastic element 9 is for example disposed in a housing of the primary element 3 which can also include a holding chute 15,

a web 11 intended to be fixed to the secondary element 5 and configured to compress the elastic element 9 during a relative rotation between the secondary element 5 and the primary element 3,

a cover 13 intended to be fixed to the primary element 3 and configured to at least partially cover the housing of the primary element 3 in which the elastic element 9 is arranged.

The primary element 3 and the cover 13 may respectively comprise a first 3a and a second half-stop 13a intended to cooperate to form a stop for the elastic element 9. The elastic element 9 is therefore compressed between the stop formed by the primary element 3 and the cover 13 on the one hand and a fin 110 of the web 11 on the other hand during a relative rotation between the secondary element 5 and the primary element 3.

FIG. 2 represents a first embodiment of a web 11 according to the present invention. The web 11 comprises an annular central portion 11a intended to be fixed to the secondary element 5 of the torsion damper 1, an annular peripheral portion 11c comprising external fins 110 which extend radially and an intermediate connection portion 1 lb between the central part 11a and the peripheral part 11c.

The annular central part 11a can comprise circular openings 112 to allow the fixing of the web 11 on the secondary element 5 of the torsion damper 1, for example by riveting. The number of circular openings 112 is for example nine as shown in FIG. 2 but another number of circular openings 112 can also be used.

The external fins 110 are configured to bear against the elastic element 9 of the torsion damper 1, for example one or more coil springs extending around the central axis of rotation X of the torsion damper 1 The external fins 110 have, for example, a shape that is flared radially outwards. The number of external fins 110 depends on the number of coil springs. In the case of FIG. 2, the web 11 comprises three external fins 110 and is intended for a shock absorber comprising three helical springs but it is also possible to use two external fins 110 as shown in FIG. 3 or any other number of external fins 110.

The intermediate link part 11b comprises an alternation of openings 114 and link arms 116 between the central part 11a and the peripheral part 11c, said link arms 116 being configured to elastically deform and allow relative rotation between the central part 11a and the peripheral part 11c by the elastic deformation of the intermediate part 11b.

At least part of the openings 114 may have an oblong shape, the largest axis of which extends radially. In addition, the openings 114 have rounded angles to limit the mechanical stresses on the periphery of the openings 114. The size of the link arms 116 (corresponding to the space between two openings 7) can vary depending on the flexibility desired. Larger openings 114 and larger link arms 116 may be provided in the areas near the outer fins 110 relative to the openings 114 and link arms 116 located at a distance from the outer fins 110. In addition, link arms 116 may be arranged in the extension of the external fins 110, the width of the link arms 116 may be less than the width of the external fins. The number of openings 114 can also be modified according to the flexibility sought. The number of openings 114 can for example vary between 10 and 25. In the case of FIG. 2, the web 1 comprises twenty-four openings. The openings 114 are for example produced by a fine cutting process (also called "fine blanking" in English).

An additional washer 20 can be associated with the web 11 to avoid excessive deformation of the web 11 and deterioration of the web 11 when a large torque must be transmitted. Figures 4 and 5 show the two faces of the additional washer 20 and Figures 6 and 7 show the assembly 22 comprising the web 11 and the additional washer

20. In the case of FIGS. 6 and 7, the web 11 comprises eight circular openings 112.

The additional washer 20, shown in FIGS. 4 and 5, has a generally annular shape whose outside diameter corresponds substantially to the diameter of the web 11 (without the external fins 110) and comprises circular openings 20a, for example eight circular openings 20a for allow the attachment of the additional washer 20 to the web 11. The circular openings 20a are for example complementary with the openings 112 (same number, here eight, and positioned on the same diameter and configured to come opposite each other) and the attachment is for example made by the fastening rivets of the web 11 on the secondary element 5 of the torsion damper 1. The additional washer 20 comprises at least one pair of stops 23, two pairs of stops 23 in the present example . The stops 23 extend axially and are intended to be positioned on either side of a connecting arm 116 of the web 11 so as to limit the relative rotation between the central part 11a and the peripheral part 11 c of the web 11 This makes it possible to limit the mechanical stresses in the sail when the force transmitted by the fins 110 of the sail is greater than a predefined value. The additional washer 20 may have a rigidity greater than the web 11 along the axis of torque transmission.

As shown in FIG. 8, in the rest state, the distance between the two stops 23 of a pair of stops 23 is greater than the width of the connecting arm 116 of the web 11 located between the two stops 23 so to leave a clearance, noted Δ, between the link arm 116 and each of the stops 23 when there is no relative rotation between the primary element 3 and the secondary element 5. The clearance corresponds for example to a rotation of at least one 0.5 degree between the central part 11a and the peripheral part 11c of the web 11. The play can go up to a value of 5 degrees. The play is for example between 0.5 degree and 5 degrees, even between 0.5 degree and 2 degrees

Thus, in operation, when the deformation of the web 11 reaches a predetermined value, the link arm (s) 116 come (s) to bear against the stop (s) so that the torsional force applied to the web 11 is taken up by the additional washer 20 which makes it possible to limit the deformation of the web 11 in the event of high transmission torque and thus to prevent deterioration of the web 11. The additional washer 20 is for example made of the same material as the web 11, for example of steel, in particular of steel of type C40. A high frequency treatment (HF) can be applied at the stops 23 and a steel reinforced with vanadium can also be used. The stops 23 are for example produced by stamping the additional washer 20.

FIGS. 1 and 9 represent a torsion damper 1 in which the peripheral part of the additional washer 20, that is to say the part intended to be opposite the peripheral part 11c of the web 11, has a shape inclined by relative to the general plane of the additional washer 20 (that is to say the transverse plane of the torsion damper 1) so that the end of the additional washer 20 is configured to come into contact with the peripheral part 11c of the web 11 at a contact zone denoted ZC. This contact zone corresponds to a friction zone between the additional washer 20 and the web 11 when the latter is deformed. This contact zone ZC allows dissipation of the mechanical energy stored by the web 11 in the form of heat when a significant torque is applied to the web 11 and deforms it.

Thus, the use of a web 11 having an annular central part 11a, an annular peripheral part 11c and an intermediate part 11b connecting the annular central part 11a and the annular peripheral part 11c comprising an alternation of openings 114 and arms of link 116 providing flexibility to the veil 11 allowing relative rotation of the peripheral annular part 11c with respect to the annular central part 11a when a significant torque is applied to the veil 11 makes it possible to provide a veil 11 which can withstand greater torques without being damaged. Indeed, the stresses on the web 11 for a given torque are lower due to the flexibility of the web 11. In addition, the combination of such a web 11 with an additional washer 20 comprising stops 23 making it possible to take up the forces undergone by the web 11 when the relative rotation between the peripheral annular part 11c and the central annular part 11a reaches a predetermined value makes it possible to further increase the value of torque that the web 11 can transmit without being damaged. In addition, the various embodiments of the present invention are inexpensive to manufacture and can be easily incorporated into known torsional dampers without requiring major modifications.

Claims (11)

1. Veil (11) for torsion damper (1) comprising elastic means (9), a first element (3) movable in rotation relative to a second element (5), said veil (11) comprising: - an annular central part (lia), - An annular peripheral part (11c) comprising external fins (110) intended to be in abutment against the elastic means (9) of the torsion damper (1), the elastic means (9) being intended to be interposed between said external fins (110) and the first element (3) of the torsion damper (1), the annular central part (11a) being intended to be fixed to the second element (5), characterized in that it comprises in addition to an intermediate part (11b) connecting the annular central part (11a) and the annular peripheral part (11c), said intermediate part (11b) comprising an alternation of openings (114) and of link arms (116) between the part annular central unit (11a) and the annular peripheral part (11c), said connecting arms (116) being configured to elastically deform and allow relative rotation between the annular central part (11a) and the annular peripheral part re (11c) by the elastic deformation of the intermediate part (11b). 2. Sail (11) according to claim 1 wherein the openings (114) have rounded corners. 3. Sail (11) according to claim 1 or 2 wherein at least some of the openings (114) are oblong openings whose major axis extends in a radial direction. 4. Sail (11) according to one of the preceding claims wherein the annular central portion (11a) comprises circular orifices (112) intended to receive rivets for fixing to the first element (3). 5. Assembly (22) for torsion damper (1) comprising: - a veil (11) according to one of the preceding claims, - an additional washer (20) intended to be fixed with the web (11) to the first element (3) and comprising at least one pair of stops (23) extending axially and intended to be positioned on either side a link arm (116) of the web (11) so that in the idle state of the web (11) there is a clearance (Δ) between the stops (23) and the link arm (116) . 6. An assembly (22) according to claim 5 in which the play (Δ) corresponds to a rotation of at least 0.5 degrees between the annular central part (11a) and the annular peripheral part (11c), in particular a play is between 0.5 and 5 degrees. 7. An assembly (22) according to claim 5 or 6 wherein the additional washer (20) has a rigidity greater than the web (11) along the axis of torque transmission. 8. Assembly (22) according to one of claims 5 to 7 in which the additional washer (20) comprises a peripheral part configured to come into contact with the annular peripheral part (11c) of the web (11) so as to create a friction zone (ZC) allowing dissipation of the mechanical energy stored by the web (11) in the form of heat when a significant torque is applied to the web (11). 9. Torsional damper (1) comprising: - a first element (3), - a second element (5) movable in rotation relative to the first element (3), - elastic means (9) intended to be interposed between the first element (3) and the second element (5) to absorb acyclisms during a torque transmission, - a veil (11) according to one of claims 1 to 4. 10. Torsional damper (1) comprising: - a first element (3), - a second element (5) movable in rotation relative to the first element, - elastic means (9) intended to be interposed between the first element (3) and the second element (5) to absorb acyclisms during a torque transmission, 5 - an assembly (22) according to one of claims 5 to 8. 11. Torsional damper (1) according to claim 9 or 10 comprising two flywheels forming a double damper flywheel.