FR2652623A1 - SELF-CENTERING CLUTCH STOP DEVICE OF THE PULL TYPE. - Google Patents

Abstract

The pulled type clutch bearing device comprises a rolling bearing (2); a guide sleeve (3) having a tubular part (15) capable of sliding on a guide tube (16) and a radial flange (17) in frictional contact with self-centering means exerting an axial force on the bearing to bearing maintained by a support element; axial connection means (4, 20) between the rolling bearing and the diaphragm (23) of the clutch. The self-centering means comprise a self-centering flange (19) having a fixing part (29) capable of cooperating with the non-rotating ring (7) of the rolling bearing and an elastic part (32) capable of exerting a force. axial between the radial flange (17) of the guide sleeve (3) and the rolling bearing (2). A seal can also be mounted between the flange (19) and one or the other of the rings (6, 7) of the rolling bearing (2).

Description

The present invention relates to a clutch release device with

  self-centering, in particular of the pull type, for motor vehicles. This type of stop works in traction and in permanent contact with the rear face of the diaphragm of the declutching device by means of axial connection means between the rolling bearing and the diaphragm of the clutch. Permanent contact is ensured during periods of operation of the device

  clutch thanks to a slight axial prestress.

  Clutch devices of this type generally include a rolling bearing and a guide sleeve which can slide on a guide tube, the rolling bearing being able to undergo radial self-centering movements during disengaging operations. It is indeed necessary to allow the rolling bearing to move radially relative to the guide sleeve and to center itself in

  operation with respect to the axis of rotation of said diaphragm.

  This self-centering function is essential for the proper functioning of the clutch bearing because, by construction, due to manufacturing tolerances and various operating clearances, the axis of rotation of the bearing and the axis of rotation of the diaphragm of the clutch do not necessarily coincide after assembly of the different elements. The stop should therefore be able to self-align with respect to the diaphragm with each clutch release operation, failing which there would be anomalies in

  functioning and premature wear of the organs.

  The self-centering means usually used generally comprise an elastic element interposed radially or axially between the rolling bearing and its support, for example the guide sleeve, the rolling bearing then having a certain degree of freedom of movement relative to this support. . French patent applications 2,553,846 and 2,545,172 (VALEO) can be cited as an example to illustrate devices

  of this type of thrust. In these patent applications, the self-

  centering of the stop is achieved by means of a corrugated washer interposed between a front face of the non-rotating ring of the rolling bearing and the flange of the guide sleeve. This wavy washer has, due to its structure, a certain elasticity and therefore exerts on the non-rotating ring of the rolling bearing an axial force tending to press it against the support element which is generally a flange in solidarity with

  cover which envelops the rolling bearing.

  If this type of self-centering washer is suitable for rolling bearings comprising solid rings as described in the aforementioned French patent applications, it is however particularly ill-suited in the case where the rolling bearing comprises rings made of stamped sheet metal . In this case, in fact, the rings of the rolling bearing are thin and their geometry lends itself poorly to the use of such corrugated washers as self-centering means due to the existence of sharp edges and the insufficiency of flat bearing surfaces for the self-centering washer. Furthermore, known self-centering washers, whether they are wavy washers as described in the aforementioned patent applications, or conical profile washers of the Belleville washer type, can only fulfill their self-centering function. However, in the case of rolling bearings comprising rings produced by stamping a sheet metal or a tube, it is frequently necessary to also provide an axial connection of the rings of the rolling bearing so that the rolling bearing once assembled constitutes a non-removable assembly during handling before the final assembly of the clutch stop device. It is also frequently necessary to provide protection and sealing for the rolling bearing. In the case of the use of self-centering washers of the conventional type, it is therefore necessary to provide a plurality of complementary elements each ensuring its

own function.

  The object of the present invention is to solve these difficulties by means of a simple self-centering means which can be used in particular for rolling bearings comprising thin rings produced by stamping a tube or a t $ le but also suitable for rolling bearings having massive rings produced by turning, said self-centering means ensuring not only the self-centering function but also a function of

  axial retention of bearing rings after assembly.

  The invention also relates to such a self-centering means which can also simultaneously provide a protective function

  and / or sealing of the rolling bearing.

  The clutch release device of the pulled type according to the invention comprises a rolling bearing, a guide sleeve

  having a tubular part capable of sliding on a tube-

  guide and a radial flange in frictional contact with self-centering means exerting an axial force on the rolling bearing maintained by the support element and connecting means

  axial between the rolling bearing and the diaphragm of the clutch.

  According to the invention, the self-centering means comprise a self-centering flange having a fixing part capable of cooperating with the non-rotating ring of the rolling bearing and an elastic part capable of exerting an axial force between the flange

  radial of the guide sleeve and the rolling bearing.

  The elastic part of the self-centering flange may advantageously have a generally conical shape similar to an umbrella.

  with a large opening angle.

  The elastic part of the self-centering flange may be solid or have a plurality of legs separated by recesses so as to

to increase its elasticity.

  The fixing portion of the self-centering flange is preferably of generally cylindrical shape in order to be able to cooperate with the external shape of the non-rotating ring of the rolling bearing. The self-centering flange is fixed in the vicinity of the free edge of the fixing part which may for this purpose comprise means for securing with the non-rotating ring of the bearing. The fixing can be done by crimping, by snap-fastening

  or by any other equivalent means.

  In an advantageous embodiment, the fixing part has elastic snap tabs which are fixed on the

non-rotating bearing ring.

  In an advantageous embodiment of the invention, the elastic part of the self-centering flange is connected to the fixing part by means of a connecting part penetrating between the two rings of the bearing in order to protect the rolling bearing, like a labyrinth seal. An elastic sealing ring can also be fitted between the flange and at least one of the rings of the rolling bearing

  to seal the bearing.

  A cover enveloping the rolling bearing and the guide sleeve generally completes the clutch stop device of the invention and plays the role of a support element for the rolling bearing against the force exerted by the flaccid

self-centering.

  In an advantageous embodiment of the invention, the bearing rings of the bearing are produced by stamping a sheet or a tube. It will however be understood that the invention can also be applied to the case where the bearing rings are massive and

made by filming.

  The invention will be better understood on studying the description

  detailed of some embodiments taken by way of nonlimiting examples and illustrated by the accompanying drawings in which: Figure 1 is a half-sectional view of a first embodiment of a clutch release device according to the invention; Figure 2 is a partial sectional half view identical to Figure 1 essentially showing the self-centering means; Figure 3 is a partial sectional half view similar to Figure 2 of an alternative embodiment; Figure 4 is a partial sectional half-view showing a second alternative embodiment of the self-centering means; Figure 5 is a similar partial sectional half-view showing a third variant of the self-centering means; Figure 6 is an external side half-view of the self-centering flange used in the clutch release device illustrated in Figures I and 2; and Figure 7 is a partial elevational view of the flange

Figure 6.

  As illustrated in FIGS. 1 and 2, the clutch device according to the invention comprises a docking part 1, a rolling bearing 2 and a guide sleeve 3. The rolling bearing 2 and the part docking 1 are secured in axial direction by an elastic fastening ring 4 which is here a split metal ring formed by a winding of a metal wire, the assembly having a general toric shape of section

  circular and being able to undergo a variation in diameter.

  The rolling bearing 2 comprises, conventionally, a plurality of balls 5 capable of rolling on the respective rolling paths of a rotating inner ring 6 and a fixed outer ring 7 produced by stamping. The balls 5 are held with regular circumferential spacings by a cage 8. The outer ring 7 has a radial flange 9 directed inward and a cylindrical portion 10. A cover 11 encloses the assembly constituted by the rolling bearing 2 and the guide sleeve 3. For this purpose, the cover 11 has at one of its ends a radial flange 12 directed inwards coming to bear axially against the flange 9 of the outer ring 7. At its other end, the cover 11 has a radial flange 13 directed towards the outside on which the fingers 14 of the clutch release fork illustrated schematically in the figure can bear and which are capable of exerting an axial traction force

  on the entire clutch release device.

  The guide sleeve 3 has a tubular part 15 capable of sliding on a guide tube 16 and a radial flange 17. The tubular part 15 extends on either side of the radial flange 17. The radial flange 17 has at its free end an annular portion 18 which engages in a housing provided on the cover 11 so as to secure the connection between the sleeve

sliding 3 and cover 11.

  An annular self-centering flange 19 is mounted on the fixed outer ring 7 and provides elastic friction contact against one of the front faces of the radial flange 17. In this way, the rolling bearing 2 can move slightly radially by relative to the guide sleeve 3 in order to allow its

  self-centering during a declutching operation.

  The docking piece 1 has a cylindrical part 20 directed towards the rolling bearing 2 and comprising an annular groove for receiving the retaining ring 4. The docking piece 1 also has at its opposite end, a toric portion 22 which comes to attack the rear face of the diaphragm 23 of the clutch. The axial connection between the docking piece 1 and the diaphragm 23 before and during the assembly operations on the vehicle is achieved by snap-fastening a washer 24 on the cylindrical part 20 of the docking piece 1 with interposition an elastic ring 25 which improves the centering of the docking part on the diaphragm before the assembly of the bearing

  bearing 2 on the docking part 1.

  The inner ring 6 has an annular rim 26 whose profile is adapted to be able to cooperate with the connecting rod 4 when the latter is housed in its receiving groove. Once mounted, the pulled clutch release device always undergoes an axial traction force directed in the same direction, this force varying between a preload value, when the clutch pedal is not actuated and an increasing clutch force during a declutching operation under the action of the fingers 14 of the declutching fork. It will be noted that the fingers 14 of the declutching fork which come to bear here on the bearing surface of the flange 13 of the cover 11 can also act directly on the

  guide sleeve 3 which then has a suitable configuration.

  The axial forces exerted by the fingers 14 of the clutch release fork are therefore transmitted by the cover 11 to the rolling bearing 2 which then retransmits them to the diaphragm 23 by means of the docking piece 1 secured to the rolling bearing 2 thanks to

the existence of the rod 4.

  An annular ring, integral with the collar 17 of the guide sleeve 3 by three flexible elastic tabs 28 can come into contact with the retaining ring 4 during the operations

assembly.

  The self-centering flange 19 has a fixing part 29 of generally cylindrical shape which comes to cooperate with the portion

  cylindrical 10 of the non-rotating outer ring 7 of the bearing 2.

  In the illustrated embodiment, the fixing of the auto flange

  centering 19 is achieved by snap-fastening a plurality of elastic fixing lugs 30 (FIG. 7), the free end 31 of which is curved to facilitate mounting of the flange 19 on the outer ring 7. As can be noted in FIG. 'examination of Figure 1 and 2 the fixing lugs 30 are slightly curved inwardly and follow the profile of the outer ring 7 thus ensuring the fixing

  of the self-centering flange 19 on the bearing 2. The self-centering flange

  centering 19 further comprises an elastic part 32 which, in the embodiment illustrated in FIGS. 1, 2, 6 and 7 is of generally conical shape similar to an umbrella with an apex angle very open in a somewhat similar manner to a Belleville washer. In the embodiment illustrated in the aforementioned figures, the elastic part 32 has a plurality of elastic tabs 33 separated from each other by recesses 34 so as to further improve the elasticity of the elastic part 32. The free ends 35 of the elastic tabs 33 are bent axially to avoid any risk of blocking during radial self-centering movements of the rolling bearing 2 accompanied by the self-centering flange 19 which remains in friction contact against the surface

  front of the radial flange 17.

  The elastic part 32 provided with its legs 33 exerts an axial force on the non-rotating ring 7 of the rolling bearing 2 which is supported by its radial flange 9 against the radial flange 12 of the cover 11 which thus serves as an axial support element for the landing at

bearing 2.

  Although we have shown here the fixing of the auto flange

  centering 19 on the non-rotating ring 7 by the snap-fastening of the elastic tabs 30, it will be understood that this fixing can be carried out in another way, for example by crimping or by any

other way.

  In the same way, the elastic part 32 which here comprises elastic tabs 33 could, in another embodiment, be

performed full.

  In the embodiment illustrated in FIG. 3 o identical or similar parts have the same references, the self-centering flange 19 has an annular connection part 36 disposed between the elastic part 32 and the fixing part 29. The part of connection 36 partially penetrates into the space between the outer ring 7 and the inner ring 6 which, in this embodiment, is devoid of the outwardly directed radial flange which it had in the embodiment illustrated on Figures 1 and 2. The connection portion 36 therefore provides a protective function of the rolling bearing 2 practically preventing the penetration of any foreign body. The connection part 36 also plays a sealing role in the manner of a labyrinth seal between the self-centering flange 19 fixed since it is integral with the fixed outer ring

  7 and the rotating inner ring 6.

  In the embodiment illustrated in Figure 4 o identical or similar parts have the same references, a sealing ring 37 having an annular lip 38 is clamped between the self-centering flange 19 and the front edge of the fixed outer ring 7. This tightening is obtained directly by the elastic tabs 30 snapped onto the outer ring 7. The sealing lip 38 is in contact with the cylindrical outer surface of the rotating inner ring 6, which has the same structure as in the embodiment. embodiment of FIG. 3, thus ensuring the tightness of the rolling bearing 2. In this embodiment, the self-centering flange 19 has practically the same structure as in the embodiment of FIGS. 1, 2, 6 and 7, the axial dimensions of the fixing part 29 being increased to hold

  account of the thickness of the ring 37.

  In the embodiment of FIG. 5 in which the identical or similar parts bear the same references, the self-centering flange 19 has, as in the embodiment illustrated in FIG. 3, a connection part 36 partly penetrating between the two rings 9 and 6. A sealing ring 39 provided with a lip 40 is also fixed in the vicinity of the free end of the elastic part 32, on the inner face of the cone, so that the sealing lip 40 comes into contact with the bore of the rotating inner ring 6. The sealing ring 39 is advantageously molded onto the elastic part 32 of the flange

self-centering 19.

  The invention makes it possible to obtain a self-centering means of simple structure capable of ensuring its self-centering function whatever the structure of the bearing rings. Although in the examples illustrated, the bearing rings were made by stamping a t8le or a tube, it will be understood that the self-centering flange illustrated can be easily modified to

  adapt to a solid ring of a rolling bearing.

  Furthermore, the self-centering flange of the invention also makes it possible to simultaneously fulfill the protection and / or

  sealing of the rolling bearing.

Claims (10)

  1. Clutch release device of the pulled type comprising a rolling bearing (2); a guide sleeve (3) having a tubular part (15) capable of sliding on a guide tube (16) and a radial flange (17) in frictional contact with self-centering means exerting an axial force on the bearing to bearing maintained by a support element; and axial connection means (4,) between the rolling bearing and the diaphragm (23) of the clutch, characterized in that the self-centering means comprise a self-centering flange (19) having a fixing part (29) capable of cooperating with the non-rotating ring (7) of the rolling bearing and an elastic part (32) capable of exerting an axial force between the radial flange (17) of the guide sleeve (3) and the rolling bearing (2).   2. A clutch stop device according to claim 1, characterized in that the elastic part (32) of the self-centering flange has a generally conical shape similar to an umbrella. 3. Clutch stop device according to claim 2, characterized in that the elastic part (32) of the flange center (19) is full.   4. Clutch stop device according to claim 2,   characterized by the fact that the elastic part of the self-flange   centering has a plurality of separate elastic tabs (33) by recesses (34).   5. Clutch stop device according to any one of   previous claims, characterized in that the part of   fixing (29) of the self-centering flange (19) is of generally cylindrical shape, capable of cooperating with the external shape of the non-rotating ring (7) of the bearing and has, in the vicinity of its free edge, means for securing with the ring non-rotating bearing. 6. Clutch stop device according to claim 5, characterized in that the fixing part (29) has elastic snap tabs (30) on the non-rotating ring (7) of the landing.   7. Clutch stop device according to any one of   previous claims, characterized in that the part   elastic (29) is connected to the fixing part (32) by means of a connecting part (36) penetrating between the   two bearing rings to protect the bearing.   8. Clutch stop device according to any one of   previous claims, characterized in that a ring   elastic seal (37, 39) is mounted between the self-supporting flange   centering (19) and at least one of the rings of the rolling bearing.   9. Clutch stop device according to any one of   previous claims, characterized in that it comprises   in addition to a cover (11) enveloping the rolling bearing (2) and the guide sleeve (3) and playing the role of axial support for the rolling bearing (2) against the force exerted by the flange self-centering (19).   10. Clutch stop device according to any one of   previous claims, characterized in that the rings   (6, 7) of the rolling bearing (2) are produced by stamping a sheet or tube.