FR2744776A1 - Clutch release with elastic element for automatic centring - Google Patents

Abstract

The clutch release has a rolling bearing (1) with revolving (11) and stationary (6) rings. The revolving ring is arranged on a guide pot (2), which has a tubular section (3), and a radial flange against which the stationary ring rests. The latter is centred automatically relative to the guide pot, by an elastic element which is arranged between them.The elastic element has a metallic band (19), whose ends approach one another in order to form a ring, and which has elastic tongues (20) which form axial stop surfaces (20a). The latter combine with retaining surfaces on the guide pot. The stationary ring has securing surfaces which combine with axial stop surfaces (21a)

Description

Clutch bearing with elastic self-aligning member.

  The present invention relates to a clutch bearing comprising a rolling bearing mounted on a guide sleeve provided with a tubular part and a radial flange on which abuts a member for actuating the bearing to move the bearing. axially so that it acts via its rotating ring on the diaphragm of a

  clutch and thus ensures its operation.

  The invention relates more particularly to the clutch stops in which an elastic self-aligning member is disposed radially between the non-rotating ring of the clutch stop bearing and the guide sleeve supporting said bearing.

stop.

  We know from German patent application 2046 282 (FICHTEL und SACHS) a self-alignment member consisting of an open metal ring formed by a metal band folded in the form of an octagon. However, such a metal ring does not participate in the axial retention of the thrust bearing on the guide sleeve

  which requires additional parts fulfilling this role.

  The elasticity of such a member is not constant along the direction of radial displacement of the bearing, which can cause problems of misalignment. Also known by the French patent application

  2 663 702 (SKF) a clutch release bearing fitted with a self-

  alignment in the form of a rubber sleeve disposed between the non-rotating ring of the bearing and the guide sleeve. The sleeve includes ribs capable of deforming radially

  so that the stop comes, during operation, self-

  align with the axis of rotation of the clutch diaphragm. Such a device is satisfactory but is limited to applications operating at relatively low temperatures. The subject of the present invention is the production of a clutch release bearing comprising an elastic self-alignment member and of axial retention of the non-rotating ring which can be produced in a simple, economical and compact manner allowing easy mounting while ensuring reliable fastening and constant elasticity whatever the displacement of the bearing and being able to withstand

high temperatures.

  The clutch bearing according to the invention is of the type comprising a rolling bearing provided with a rotating ring and a non-rotating ring and mounted on a guide sleeve provided with a tubular part and a radial flange on which bears the non-rotating ring of the bearing, an elastic self-alignment member of the non-rotating ring relative to the guide sleeve being disposed radially between the rotating ring and a tubular part of the guide sleeve. The elastic self-alignment member comprises a metal strip, the ends of which are brought together to form a ring, said strip being provided with elastic tongues and abutment surfaces cooperating with retaining surfaces of the guide sleeve and the Ring

not rotating.

  Thanks to such a metal strip, the clutch bearing can withstand high temperatures while being of simple structure and

  economical, the metal strip constituting the self-

  elastic alignment also serving to axially retain the

  bearing in contact with the guide sleeve.

  The elastic tongues are advantageously separated from each other at least by a transverse bar. The elastic tabs can be cut from the metal strip in the circular direction and supported by the crossbars or else

  can be cut from the metal strip in the axial direction.

  In one embodiment of the invention, the metal strip comprises a plurality of corrugations regularly distributed annularly and intended for the axial retention of the non-rotating ring while facilitating the centering of the metal strip in the bore of the non-rotating ring rotating. In another embodiment of the invention, the metal strip comprises a plurality of radial tongues which form abutment surfaces cooperating with radial surfaces of the non-rotating ring. The radial tabs can be cut on one edge of the metal strip, on both edges or in the center of the metal strip. In the latter case, the radial tabs can

  be cut near the elastic tabs.

  In order to seal the bearing, an edge of the metal strip advantageously forms a narrow passage with the

rotating bearing ring.

  In one embodiment of the invention, the metal strip is disposed between a shoulder of the tubular part and the flange of the guide sleeve. The tongues project from the metal strip in the direction of the non-rotating ring, their edges forming abutment surfaces intended to cooperate with the non-rotating ring. Preferably, the non-rotating ring is provided with a circular groove capable of cooperating with the abutment surfaces of the

elastic tabs.

  In another embodiment of the invention, the guide sleeve comprises a second tubular part surrounding the non-rotating outer ring of the bearing, the metal strip being disposed between the outer surface of the non-rotating ring and

  the bore of the second tubular part.

  The invention will be clearly understood on studying the description

  detailed of some embodiments taken by way of non-limiting examples and illustrated by the appended drawings in which: FIG. 1 is a side view in section of a clutch bearing according to a first embodiment of the invention ; Figure 2 is a sectional view along II-II of Figure 1; Figure 3 is an enlarged view of a detail of Figure 1 showing in particular the shoulder of the tubular part of the guide sleeve; Figures 4 and 5 are flat exterior views after cutting two variants of the metal strip; Figure 6 is a cross-sectional view of the metal strip of Figure 5 after complete forming of the strip; Figure 7 is a longitudinal sectional view of the metal strip of Figure 5 after complete forming of the strip; Figures 8 to 12 are flat exterior views after cutting of various embodiments of the metal strip; Figure 13 is a cross-sectional view of the metal strip of Figure 9 after complete forming of the strip; Figure 14 is a longitudinal sectional view of the metal strip of Figure 10 after complete forming of the strip; Figure 15 is a partial sectional view of a clutch bearing provided with the variant of the metal strip of Figure 14; Figure 16 is a variant of Figure 15; Figure 17 is a sectional view similar to Figure 2 of the clutch bearing provided with the metal strip of Figure 8; Figure 18 is a partial sectional view of a clutch release bearing according to another embodiment of the invention; Figure 19 is a flat view of the metal strip of Figure 18; Figure 20 is a side view of the metal strip of Figure 18; Figure 21 is a partial section of a clutch bearing according to another embodiment of the invention; Figure 22 is a flat view of the metal strip of Figure 21; Figures 23 to 25 are flat views of alternative metal strips; Figure 26 is a longitudinal sectional view of a variant of the metal strip of Figure 21; Figure 27 is a partial sectional view of a clutch release bearing according to another embodiment of the invention; Figure 28 is a flat view of the metal strip of Figure 27; Figure 29 is a cross-sectional view of the metal strip of Figure 27; and Figure 30 is a partial sectional view of a stop

  clutch according to another embodiment of the invention.

  As illustrated in FIGS. 1 and 2, the clutch stop according to the invention comprises a rolling bearing 1 mounted on a guide sleeve 2, advantageously made of synthetic material and which comprises a tubular portion 3 which can slide with respect to a guide tube 4 shown in dotted lines in FIG. 1 and a radial flange 5. The rolling bearing 1 has an inner race ring 6 with a thin wall produced by stamping a sheet metal or a tube having an O-ring race 7 for a row of balls 8 held in a cage 9. The inner ring 6 also has an extension directed towards the outside in the form of a radial flange 10 which comes into frictional contact on the surface inner frontal of the

radial collar 5.

  The rolling bearing 1 is completed by an outer ring 11 also with a thin wall produced by stamping a sheet or tube which has an O-ring raceway 12 for the balls 8 as well as a radial portion 13 which comes in contact with the surface of the diaphragm 14 of a clutch device during the longitudinal displacement of the assembly of the stop relative to the guide tube 4 on which slides the guide sleeve 2. The rolling bearing 1 is protected by a protective flange 15 fixed on the

outer ring 11.

  The radial flange 5 of the guide sleeve 2 has a metal ring 16 on which is overmolded said radial flange 5. This ring 16 which has preferably undergone a surface hardening treatment, serves as a contact surface for an operating member 17 shown in dotted lines in FIG. 1 and which exerts a force in the axial direction to cause the displacement of the stop

  as a whole during a declutching operation.

  The axial connection of the operating member 17 with respect to the guide sleeve 2 is done by means of retaining portions 18 which form hooks arranged on the outside diameter of the radial flange 5 of the guide sleeve 2. The mounting of the operating member 17 is done by axial thrust causing the bending of the

  retaining portions 18 of the guide sleeve 2.

  A member for elastic self-alignment and axial retention of the non-rotating ring 6 relative to the guide sleeve 2, referenced 19 as a whole and in the form of a metal strip, is arranged radially between said ring non-rotating 6 and the tubular part 3 of the guide sleeve 2. The metal strip 19 forms after fitting a closed ring comprising elastic tongues 20 and undulations 21, 22

  evenly distributed along the strip.

  As can be seen more particularly in FIG. 2, the metal strip 19, of small thickness, is of slightly larger diameter than the tubular part 3 of the guide sleeve 2 and is centered on the latter by the elastic tongues 20. The free end of the tubular part 3 comprises a shoulder 3a on its outside diameter (FIG. 1), which is in contact with the edge 20a of the elastic tongues 20 thus preventing the metal strip 19 from moving axially towards the outside of the guide sleeve 2. The edge 20a of the elastic tabs 20 thus forms a stop surface for the strip

  metal 19 against the retaining surface formed by the shoulder 3a.

  The corrugations 21, 22 of the metal strip 19 are located at the lateral ends of the latter. The corrugations 21 located on the outside of the non-rotating ring 6 have their edges 21a in axial contact with the radial surface 6a of the end of the non-rotating ring 6. The edges 21a of the corrugations 21 therefore form abutment surfaces in contact with the radial end surface 6a of the non-rotating ring 6 and thus retain the non-rotating ring 6 relative to the metal strip 19 and to the guide sleeve 2 against an axial displacement towards the outside c that is to say towards the diaphragm 14. The corrugations 22 located on the side of the guide sleeve 2 are in contact with a bore of the non-rotating ring 6 and maintain the centering of the metal strip 19 on the non-rotating ring

rotating 6.

  The clutch bearing illustrated in FIG. 3 is identical to that of FIG. 1, except for the non-rotating ring 6 whose free end on the outside, that is to say on the side opposite to the radial portion, is ends with a radial surface 6a corresponding to the thickness

  of the sheet forming said non-rotating ring 6.

  As seen more particularly in Figures 4 to 7, o the metal strip 19 used in the embodiments illustrated in Figures 1 and 3 is shown before assembly, in the free state that is to say flat , said metal strip 19 comprises on its lateral ends, two strip portions 23, 24 interconnected by transverse bars 25. The strip portions 23 and 24 and the transverse bars 25 define windows 26. The corrugations 21, 22 of the metal strip 19 are formed, respectively, in the strip portions 23, 24 at the level of a window 26. The tongues 20 extend circularly from the transverse bars 25 and form

  protruding in the opposite direction to that of the corrugations 21, 22.

  In the embodiment illustrated in FIG. 4, one crossbar 25 out of two supports an elastic tongue 20. The following crossbar 25 is devoid of it. In the embodiment illustrated in FIGS. 5 to 7, each transverse bar 25 supports an elastic tongue 20. This embodiment provides a

  firmer centering than that in Figure 4.

  The metal strip 19 is manufactured in the following manner. The windows 26 are cut by punching a solid metal strip, for example made of spring steel. Depending on the embodiment chosen (FIG. 4 or FIG. 5), a punching tool of suitable shape is used to obtain a crossbar 25

  without tongue 20 or on the contrary provided with tongue 20.

  Then, by folding, the elastic tongues 20 and the corrugations 21, 22 are given their shape. The metal strip 19 is cut to the desired length according to the type of clutch so that the metal strip 19 forms a ring after it has been fitted. The metal strip 19 is placed inside the bore of the non-rotating ring 6 of a rolling bearing 1, the ends of the metal strip 19

  being in mutual contact and possibly overlapping.

  As the metal strip 19 tends to return to its initial flat shape, it remains alone with respect to the non-rotating ring 6. To mount the assembly formed by the rolling bearing 1 and the metal strip 19 on the bushing. guide 2, the non-rotating ring 6 is approached from the guide sleeve 2 by an axial movement. Simultaneously, the radial flange 10 of the non-rotating ring 6 comes into contact with the inner front surface of the radial flange 5 and the elastic tongues 20 snap into the shoulder 3a of the tubular part 3 and ensure the axial retention of

  the non-rotating ring 6 relative to the guide sleeve 2.

  In operation, when a misalignment occurs between

  the non-rotating ring 6 and the guide sleeve 2, the self-

  elastic alignment formed by the metal strip 19 is deformed, the elastic force being provided both by the bending of the tongues 20 and by the twisting of the transverse bars 25 which

  guarantees great flexibility and good stress distribution.

  As the metal strip 19 has joined ends to form a ring, the elastic force is constant whatever the direction

misalignment.

  The embodiments illustrated in Figures 8 to 12 retain the same references as above for similar elements. In the embodiment illustrated in FIG. 8, the metal strip 19 is devoid of corrugations and includes strip portions 23, 24 connected by transverse bars 25 supporting elastic tabs 20. The strip portion 23 supports on its edge exterior a plurality of tabs 27 intended to be folded radially outward and come into contact with the radial surface 6a of the end of the non-rotating ring 6 to form a stop surface preventing axial movement of the

  non-rotating ring 6 relative to the guide sleeve 2.

  The metal strip 19 illustrated in FIGS. 9 and 13 comprises two rows of tongues 27, 28 folded radially and cut respectively in the strip portions 23, 24 which are wider than in the embodiment of FIG. 8. The radial tongues 28 extending outwards, are in contact with the bore of the non-rotating ring 6 for precise centering of the

  metal strip 19 relative to the non-rotating ring 6.

  The metal strip 19 illustrated in FIGS. 10 and 14 comprises tabs 29 supported by the inner edge of the strip portion 23, that is to say protruding before folding in a window 26. The tabs 29 are folded radially towards the outside to form abutment surfaces as explained above. A transverse bar 25 on two supports an elastic tongue 20. The tongues 29 before folding, and the elastic tongues 20 make

  alternately protruding in the windows 26.

  The embodiment illustrated in FIG. 11 is identical to that illustrated in FIG. 10 except that the tongues 30 intended to be folded radially outwards are supported by the internal edge of the strip portion 24 and are screwed with respect to the tongues 29. The tongues 30 have the same function as the

tabs 28 of FIG. 9.

  The embodiment illustrated in FIG. 12 comprises tongues 29, 30 which project in the same window 26 as an elastic tongue 20. Each transverse bar 25 supports an elastic tongue 20 so as to ensure firmer centering than

  that provided by the embodiments of FIGS. 10 and 11.

  The clutch bearing illustrated in Figures 15 and 17

  comprises a metal strip 19 similar to that of FIG. 10.

  The strip portion 23 extends axially outwards in the direction of the diaphragm of the clutch and of the rotating ring 11 to form a narrow passage 31 ensuring the sealing of the bearing 1. The narrow passage 31 is formed between the portion strip 23 and the free end 13a of the radial portion 13 of the rotating ring 11. The metal strip 19 forms a ring and one of its ends 19a (FIG. 17) overlaps the other end 19b for a short length . We can also consider bringing the two ends 19a and 19b closer by placing them in contact with each other, that is to say

  end or close to each other.

  FIG. 16 illustrates an embodiment identical to that of FIG. 15 except that the narrow passage 31 is formed between the strip portion 23 and an annular groove 13b provided on the inner radial surface 13c of the radial portion 13 of the rotating ring 11. The groove 13b can be obtained, for example, by flat stamping at the blank of the blank of the ring 11 or by recovery with

  chip removal from the finished ring 11.

  Figures 18 to 20 show a different embodiment of the clutch stop. The rolling bearing 1 comprises an inner rotating ring 11, provided with a radial portion 13 extending radially outward on the side of the clutch diaphragm, and an outer non-rotating ring 6, provided with a radial portion 10 in contact with the collar 5 of the guide sleeve 2, extending radially inwards and supporting near the tubular part 3 a cylindrical portion 10a. The metal strip 19 has elastic tongues 32 cut by punching in the center and lengthwise of the metal strip 9 and projecting radially outwards. The windows 26 are of reduced dimensions and corresponding to those of the elastic tabs 32. As a result, there is no loss of material during the

  fabrication of the metal strip 19.

  The metal strip 19 is housed axially between the shoulder 3a of the tubular part 3 and the radial flange 5 and is in contact with the outer surface 3b of the tubular part 3. The tongues 32 extend radially outwards in the direction of the cylindrical portion 10a of the non-rotating ring 6 which comprises a bore 6b. The bore 6b of the non-rotating ring 6 is provided with a groove 33 the bottom of which is in contact with the elastic tongues 32. The edges 32a of the elastic tongues 32 form abutment surfaces in contact with the edges 33a of the groove 33 and thus axially retain the non-rotating ring 6 relative to the guide sleeve 2. The non-rotating ring 6 is here an outer ring and the

  rotating ring 11 is an inner ring.

  This simplified embodiment is particularly economical while ensuring the self-alignment of the bearing 1 relative to the guide sleeve 2 thanks to the radial flexibility of the elastic tabs 32 and the axial retention of the bearing 1 relative to the guide sleeve 2 thanks to the contact of the edges 32a of the elastic tongues 32 with the edges 33a of the groove 33 and to the retention of the metal strip 19 by the shoulder 3a. The embodiment illustrated in FIG. 21 differs from that of FIG. 1 in that the metal strip 19 also visible in FIG. 22 includes elastic tongues 34 supported by the inner edge of the strip portion 24, the transverse bars 25 being lacking. The axial retention of the metal strip 19 relative to the tubular portion 3 is ensured by the contact between the end 34a of the elastic tongue 34 with the shoulder 3a. This arrangement of the tabs 34 facilitates the mounting of the bearing 1 equipped with the metal strip 19 on the guide sleeve 2. In fact, during mounting, the elastic tabs 34 are bent radially outward by the end of the tubular portion 3 then snap into the shoulder 3a. The corrugations 21, 22 of the metal strip 19 are identical to those of the embodiment of the

figure 1.

  In the embodiment illustrated in FIG. 23, the metal strip 19 is devoid of corrugation but includes tongues 27, 28 intended to be bent radially outwards to form abutment surfaces cooperating with the non-rotating ring 6. The tabs 27, 28 are supported respectively on

  the outer edge of the strip portions 23, 24.

  The metal strip 19 of Figure 24 is very close to that of Figure 23 except that the tabs 27, 28 intended to be folded radially outward are cut respectively

in the strip portions 23, 24.

  The metal strip 19 of FIG. 25 comprises tongues 29 intended to be folded radially outwards and supported by the inner edge of the strip portion 23. Each tongue 29 projects, before its folding, in a window 26 opposite

of the elastic tongue 34.

  The metal strip 19 illustrated in FIG. 26 is similar to that illustrated in FIG. 22, except that between each corrugation 22 and each elastic tongue 34 is arranged a bar

transverse 25.

  In the embodiments of FIGS. 21 to 26, the strip portion 24 can be elastically deformed by torsion when the elastic tongues 34 bend, and thus participates in the effort

elastic self-aligning.

  The embodiment illustrated in Figures 27 to 29 comprises a metal strip 19 of simplified shape. The rolling bearing 1 is similar to that of FIG. 15, except that the non-rotating ring 6 is extended axially towards the rotating ring 11, the radial surface 6a being disposed near the latter. The metal strip 19 is housed axially between the shoulder 3a of the tubular portion 3 and the radial flange 5 and is in contact with the outer surface 3b of the tubular portion 3. The metal strip 19 comprises elastic tongues 35 cut in the direction axial and projecting radially outwards in the direction of a bore 6c of the non-rotating ring 6 provided with an annular groove 36. The elastic tongues 35 are supported by the inner edge of the strip portion 23 and project in oblique not only radially outwards but also axially in the direction of the radial flange 5. When mounting the bearing 1 on the guide sleeve 2, the elastic tongues 35 are first of all folded down by the bore 6c of the ring non-rotating 6 then the metal strip 19 engages in the housing formed by the shoulder 3a and thus ensures the axial retention of the non-rotating ring 6 relative to the guide sleeve 2. The radial edge 35a of the end of the tongues

  forms a stop surface to retain bearing 1.

  In FIG. 30, the references of the elements similar to those of the preceding figures have been increased by the number 100. The clutch bearing comprises a bearing 101, the rings of which are produced by removal of chips with an outer non-rotating ring 106 and a ring. rotating interior 111 capable of coming into contact with a clutch diaphragm, not shown, thanks to a portion 111 a projecting axially opposite the guide sleeve 102. The guide sleeve 102 further comprises the first tubular part 103 and the radial flange 105, a second tubular portion 137 supported by the outside diameter of the radial flange 105 and radially surrounding the bearing 101. The self-aligning metal strip 119 is disposed between the second tubular portion 137 and the ring non-rotating 106. The bore of the second tubular portion 137 is provided with an annular groove 137a of suitable dimensions to receive the metal strip 119 and thus ensure the axial retention of the metal strip 119. The metal strip 119 is identical to that illustrated in FIGS. 28 and 29 but is mounted in the other direction, that is to say that the elastic tongues 135 protrude radially inwards and are snapped into an annular groove 138 of the non-rotating ring 106. The radial edge 135a of the end of the tongues 135 forms a

  stop in contact with the edge 138a of the groove 138.

  It can therefore be seen that the rolling bearing 101 can self-

  align with respect to the guide sleeve thanks to the flexibility of the tongues 135 but cannot deviate axially from these thanks to the contact between the abutment edges 135a and the edge 138a of the groove

138.

  The clutch release bearing according to the invention is particularly economical insofar as it comprises fewer parts than the known stops. In addition, the elastic self-alignment member is of small radial size and its self-centering capacities are stable over time whatever the temperature of use. Finally, it is possible to use a single type of elastic self-aligning member for several types of stop, only the length of cut of the strips.

may differ.

Claims (14)

  1. Clutch bearing of the type comprising a rolling bearing (1) provided with a rotating ring (11) and a non-rotating ring (6) and mounted on a guide sleeve (2) provided with a part tubular (3) and a radial flange (5) on which the non-rotating ring (6) of the bearing comes to bear, an elastic self-alignment member of the non-rotating ring (6) relative to the bushing guide (2), being disposed radially between the non-rotating ring (6) and a tubular part (3) of the guide sleeve characterized in that the elastic self-alignment member comprises a metal strip (19), the ends are brought together to form a ring, said strip being provided with elastic tongues (20) and abutment surfaces (20a, 21a) cooperating with retaining surfaces of the guide sleeve   (2) and the non-rotating ring (6).   2. Clutch bearing according to claim 1, characterized in that the elastic tongues (20) are separated from one another   others at least by a transverse bar (25).   3. clutch bearing according to claim 1 or 2, characterized in that the tongues (20) are cut from the metal strip (19) in the circular direction and are supported by the bars transverse (25).   4. Clutch bearing according to claim 1 or 2, characterized in that the tongues (20) are cut in the strip   metallic (19) in the axial direction.   5. Clutch bearing according to any one of   previous claims, characterized in that the metal strip   (19) includes a plurality of corrugations (21, 22) regularly distributed annually.   6. Clutch bearing according to one of claims 1 to 4, characterized in that the metal strip (19) comprises a plurality of radial tongues (27) forming cooperating stop surfaces with the non-rotating ring (6).   7. Clutch bearing according to claim 6, characterized in that the radial tongues (27) are cut on one edge of the metal strip (19).   8. Clutch bearing according to claim 6, characterized in that the radial tongues (27, 28) are cut on the two edges of the metal strip (19).   9. Clutch bearing according to claim 6, characterized in that the radial tongues (29, 30) are cut in the center of the metal strip (19).   10. Clutch bearing according to claim 9, characterized in that the radial tongues (29, 30) are cut close elastic tabs (20).   1. Clutch bearing according to any one of   previous claims, characterized in that an edge of the strip   metallic (19) forms a narrow passage (31) with the rotating ring   (11) so as to seal the bearing.   12. Clutch bearing according to any one of   Claims 1 to 5, characterized in that the metal strip (19)   is arranged between a shoulder (3a) of the tubular part (3) and the flange (4) of the guide sleeve, the tongues (32) projecting from the metal strip in the direction of the non-rotating ring (6) and the edges (32a) of the tabs forming abutment surfaces   intended to cooperate with the non-rotating ring.   13. Clutch bearing according to claim 12, characterized in that the non-rotating ring (6) is provided with a groove (33) capable of cooperating with the abutment surfaces of the tongues elastic (32).   14. Clutch bearing according to any one of   previous claims, characterized in that the socket   guide (102) comprises a second tubular part (137) surrounding the non-rotating outer ring of the bearing, the metal strip being disposed between the outer surface of the non-rotating ring and   the bore of the second tubular part.