FR2813647A1 - Clutch operator has elastic compensating sleeve with metal annular core with gap extending between end faces and radially extending shoulder interacting with end face of stationary ring of rolling bearing - Google Patents

Abstract

The clutch operator has an elastic compensating sleeve(14) fitted between the bore of the stationary ring(7) of a rolling bearing and seat face(3a) of a sliding sleeve(3). The compensating sleeve has a metal annular core(16) with a gap extending from one end face as far as the opposite lying end face. The gap runs parallel to the axis of the compensating sleeve or at an angle to it. The core has a shoulder(16a) extending radially and interacting with an end face of the stationary ring of the rolling bearing.

Description

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The present invention relates to a declutching stop device, in particular for motor vehicles and in particular a declutching stop device of the type comprising an elastic self-aligning sleeve.

Such declutching stop devices comprise a rolling bearing mounted on an operating element generally produced in the form of a guide sleeve which can move axially under the action of a control member produced for example in the form of '' a piston or a control fork. The rolling bearing can cooperate with a diaphragm of the clutch by means of an attack element integral with the rolling bearing or fixed thereon. In order to make up for any misalignment between the axis of the clutch diaphragm and the axis of the bearing, the rolling bearing is provided to be able to move radially relative to the operating element within the necessary limit. to the self-alignment of the bearing with respect to the diaphragm of the clutch.

The rolling bearing of the clutch release bearing conventionally comprises a rotating ring, comprising a driving element, intended to cooperate with the diaphragm of the clutch, and a non-rotating ring. Between the two rings of the rolling bearing, there are disposed rolling elements which are generally balls.

Advantageously, the declutching stop device has sealing means making it possible, on the one hand to avoid the exit of the grease used for the lubrication of the rolling bearing and, on the other hand to prevent the re-entry of foreign particles likely to come

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 pollute the inside of the rolling bearing.

To ensure the desired self-alignment effect, the rolling bearing is usually mounted on the operating element by means of an elastic sleeve, allowing the rolling bearing to move radially relative to to the operating element. There is thus obtained a self-alignment of the rolling bearing equipped with the driving element relative to the diaphragm of the clutch. Furthermore, the sleeve makes it possible to ensure the axial retention of the rolling bearing on the operating element by cooperating for example with a retaining element, such as a bead provided at one of the ends of the operating element. .

The elastic sleeve is usually of generally tubular shape and has substantially radial lamellae or ribs inside its bore, which may preferably have a section that tapers inwards and are produced so as to be able to flex radially. resiliently to perform the self-alignment function.

 In order to guide the rolling bearing radially in its self-aligning movement, the rolling bearing generally comes to bear via its non-rotating ring against a flat radial surface forming part of the operating element. Such a clutch release device is described for example in French patent application 2,663,702.

The rolling bearing may include rings made of stamped sheet metal or, on the contrary, solid rings with rectified bore. The elastic sleeve allowing self-alignment is generally made of an elastic synthetic material, such as rubber. It has a relatively thick body, of generally tubular shape, inside which are arranged the radially deformable strips or ribs.

Provision has already been made in French patent application 2,779,193 for producing such an elastic sleeve by overmolding a synthetic material, for example an elastomer, on a metal insert, a layer of synthetic material covering the external periphery of the sleeve, so as to obtain a precise position and a good fit

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 of the sleeve relative to the non-rotating ring of the rolling bearing. But such an embodiment is done to the detriment of the radial size of the elastic sleeve and therefore of the entire clutch release device, which in some cases is not acceptable.

In the release devices of known type, comprising a tubular metal insert, as is the case in patent application FR 2 779 193, the insert is a part generally produced by stamping or from a tube non-machined whose outside diametral dimensions are relatively imprecise. In addition, the dimensions of the bore of the rolling bearing are themselves relatively imprecise, in particular in the case of a rolling bearing whose rings are made of pressed sheet metal. This results in mounting and adaptation difficulties.

The object of the invention is therefore to provide a declutching stop device in which the difficulties resulting from the imprecision of the diametrical dimensions of the tubular insert and, as the case may be, of the non-rotating ring of the rolling bearing, are are resolved, while limiting as much as possible the radial size of the elastic sleeve and of the clutch release bearing device as a whole.

The clutch release device according to the invention comprises, a rolling bearing provided with a rotating ring and a non-rotating ring and provided with a driving element capable of cooperating with a clutch diaphragm, a operating element capable of moving axially in translation under the action of a control member and an elastic self-aligning sleeve radially mounted between the bore of the non-rotating ring and a bearing surface of the operating element . The sleeve comprises a metal insert of generally annular shape and an elastic portion made of a synthetic material in contact with the bearing surface of the operating element. The insert has a slot extending from one of its axial faces to the opposite axial face. In this way, the sleeve can easily adapt to the diameter of the bore of the ring of the rolling bearing which receives it, within a wide tolerance range.

The slot of the insert can be parallel or oblique with respect to the axis of the sleeve.

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 The insert may advantageously have a substantially radial flange cooperating with a radial face of the non-rotating ring of the rolling bearing so as to form an axial stop of the sleeve on the ring of the rolling bearing.

In a preferred embodiment, the insert is in direct contact with the bore of the non-rotating ring of the rolling bearing, thus ensuring minimal radial bulk. As a variant, an external layer of synthetic material may be provided enclosing the insert and coming into contact with the bore of the ring of the bearing so as to further improve the precision of the mounting.

The external diameter of the sleeve in the free state, before its assembly, is preferably slightly greater than the diameter of the bore of the non-rotating ring of the rolling bearing. The sleeve thus adjusts by elasticity, without excessive tightening but with sufficient support, in the bore of the bearing ring. The assembly consisting of the rolling bearing and the sleeve can also thus be handled without risk of dismantling accidental sleeve. Once the bearing is mounted on the operating element, the sleeve cannot open or close and perfectly fulfills its functions of self-alignment and axial retention like a conventional sleeve without slot.

The elastic portion of the sleeve can be interrupted at the location of the slot of the insert or, on the contrary, fill the slot of the insert, depending on the circumferential elasticity desired for the sleeve.

In an advantageous embodiment, the elastic portion of the sleeve has an axial retaining bead cooperating with the non-rotating ring of the rolling bearing. When the elastic portion of the sleeve fills the slot of the insert, said bead is preferably interrupted at the location of the slot of the insert in order to ensure sufficient elasticity of the sleeve in the circumferential direction.

The attachment of the insert to the elastic portion of the sleeve can be carried out in any suitable manner. Preferably, the elastic portion of the sleeve is molded onto the insert.

The elastic portion of the sleeve preferably has a plurality of internal ribs of self-alignment inclined with respect to the radial direction and of section decreasing inwards.

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 In a preferred embodiment of the invention, the rings of the rolling bearing are of stamped sheet metal, the attack element being constituted by a portion of the rotating ring. The non-rotating ring advantageously has a radial flange in frictional contact with a radial surface of the operating element so as to radially guide the self-aligning movements of the rolling bearing.

In another embodiment of the invention, the rolling bearing is of the conventional type and comprises solid rings with a rectified cylindrical bore, the driving element being fixed by any suitable means on the rotating ring.

In all cases, the elastic portion of the sleeve preferably has a sealing lip cooperating with the driving element. The invention also relates to an assembly intended for producing a declutching stop device and comprising, a rolling bearing provided with a rotating ring and a non-rotating ring and provided with an element of attack able to cooperate with a clutch diaphragm as well as an elastic self-alignment sleeve, radially mounted in the bore of the non-rotating ring. The sleeve comprises a metal insert of generally annular shape and an elastic portion made of a synthetic material. The insert has a slot extending from one of the axial faces of said insert to the opposite axial face.

Such an assembly can be marketed and transported as it is without risk of separation of the elements which constitute it before being mounted on an operating element to constitute a clutch release device.

The invention will be better understood from the study of a few embodiments taken by way of nonlimiting examples and illustrated by the appended drawings, in which - FIG. 1 is a view in axial section of a clutch release device , according to the invention, in a first variant; - Figure 2 is an axial sectional view along II-II of Figure 6, of an assembly intended to form a clutch release device, as illustrated in Figure 1 after mounting on an operating element; - Figure 3 is a perspective view of a metal insert

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 used for the manufacture of an elastic sleeve in a clutch release device, according to the invention; - Figure 4 is a perspective view of an alternative insert; - Figure 5 is a perspective view of another variant of an insert; - Figure 6 is an external side view with a partial cutaway seen in partial cross section of an elastic sleeve provided with a metal insert used in an assembly, as illustrated in Figure 2; - Figure 7 is an axial sectional view similar to that of Figure 1, of a variant of a clutch release device, according to the invention; - Figure 8 is a cross-sectional view of an elastic sleeve used in a clutch release bearing, according to the invention; - Figure 9 is an enlarged cross-sectional view of part of the elastic sleeve of Figure 8, at the location of the slot of the insert; and - Figure 10 is an enlarged sectional view similar to that of Figure 9, of a variant of elastic sleeve.

As illustrated in FIG. 1, the declutching stop device according to the invention comprises a rolling bearing 1 mounted on an operating element 2, being in the form of a guide sleeve comprising a tubular portion 3 which can slide relative to a guide tube 4 and a radial flange 5. The radial flange 5 of the operating element 2 is formed by a metal ring, on which is overmolded the tubular portion 3 made of rigid synthetic material, for example made of synthetic material with added mineral fillers or the like. The radial flange 5 has preferably undergone a surface hardening treatment and serves as a contact surface for a control member 6, for example of the "control fork" type capable of exerting a force in the axial direction to cause the axial displacement of the stop device as a whole along the guide tube 4 during a declutching operation.

The rolling bearing 1 comprises an inner ring 7, not rotating, having an O-ring race 8 for a row of

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 balls 9 held in a cage 10. The non-rotating inner ring 7 comprises a bore 7a, and a radial flange 7b directed outwards, in frictional contact with the radial flange 5 of the operating element 2, so to guide the radial self-alignment movement of the rolling bearing 1.

The rolling bearing 1 further comprises a rotating outer ring 11, comprising an O-ring raceway 12 for the row of balls 9. The outer ring 11 is extended on one side by a cylindrical part 11a, and on the other side by a substantially radial part 11b having a convex zone which acts as an attack member and is capable of coming into contact with the diaphragm 13 of the clutch of a motor vehicle. A seal 10a is mounted between the cylindrical portion 11a of the rotating outer ring 11 and a corresponding portion of the non-rotating inner ring 7 on the side facing the radial flange 5 of the operating element 2.

The two rings 7 and 11 of the rolling bearing 1 are made of pressed sheet metal from blanks coming from a sheet metal strip.

A self-alignment sleeve 14 is disposed between the tubular portion 3 of the operating element 2 and the bore 7a of the non-rotating ring 7 of the rolling bearing 1. The elastic sleeve 14, made for example of elastomer or natural rubber, has a plurality of self-aligning ribs 15, also visible in Figure 2, arranged parallel to the axis of the stop device and directed inward. The ribs 15 are slightly inclined relative to the radial direction, as can be seen in particular in FIG. 6. In addition, their cross section decreases inwards, their end being slightly rounded. The choice of this particular shape for the ribs 15 and of the material used for the sleeve 14 makes it possible to obtain the desired flexibility so as to obtain the desired self-alignment effect for the clutch release device. The internal free edge of the different self-aligning ribs 15 comes into contact with the external cylindrical surface 3a of the tubular portion 3 of the operating element 2.

The elastic sleeve 14 comprises a metal frame produced in the form of an insert 16, which is of generally annular shape and

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 the external cylindrical surface of which comes into direct contact with the bore 7a of the non-rotating inner ring 7 of the rolling bearing 1. In the example illustrated in FIGS. 1, 2, 3 and 6, the insert 16 has at in addition to a radial flange 16a which comes into contact with the front end face of the non-rotating inner ring 7, thus providing a stop for the elastic sleeve 14 when the latter is mounted inside the bore of the non-rotating ring 7, from the left to the right of FIG. 1. As a variant, the insert 16 could be, at least in part, embedded in the synthetic material constituting the sleeve, to the detriment, however, of the compactness radial of the assembly.

The synthetic material constituting the elastic sleeve 14 and the self-aligning ribs 15, is overmolded in the example illustrated, only inside the metal insert 16. An annular bead 17, located on the sleeve 14 to 1 'opposite of the radial flange 16a of the insert 16, cooperates with a rounded portion 7c of the non-rotating ring 7, so as to axially immobilize the elastic sleeve 14 relative to the non-rotating ring 7. The bead 17 therefore constitutes a second axial stop in the opposite direction to that formed by the radial flange 16a.

An annular sealing lip 18 is part of the elastic sleeve 14 and comes into sealing contact with the internal face of the portion 11b of the rotating ring 11, thus completing the sealing of the rolling bearing 1 produced on the other side. by seal 10a.

Maintaining the axial position on the operating element 2 of the assembly formed by the rolling bearing 1 and its elastic self-aligning sleeve 14, is ensured by an annular projecting rim 19 provided on the end edge of the tubular portion 3 of the operating element 2.

 The metal insert 16, used in the clutch release device illustrated in Figure 1, has the structure visible in Figure 3. The insert 16 has a slot 20 which extends from one of its axial faces to 'to its opposite axial face, which therefore provides the insert with a retraction capacity of its diameter under the action of a clamping effect when the insert 16 is mounted inside the bore 7a of the non-rotating ring 7. It is understood that the elastic sleeve 14 comprising the insert

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 16 and the plurality of self-aligning ribs 15 can thus be adjusted by elasticity in the bore 7a of the rolling bearing 1.

The elastic sleeve 14, used in the declutching device illustrated in Figure 1, is visible in Figure 6, on which we find the metal insert 16. The synthetic material of the sleeve 14 molded into the bore of the insert 16 , completely fills the slot 20 with a bridge of material 21. The peripheral bead 17 is nevertheless interrupted at the location of the material bridge 21, so as to improve the elasticity at the location of the slot 20 of the insert 16 The material constituting the trigger guard 21 can thus easily contract during assembly of the elastic sleeve 14 in the bore 7a of the ring 7.

Figures 4 and 5 illustrate two variants of metal insert, shown before overmolding of the synthetic material. In the variant illustrated in FIG. 4, the insert 22 comprises, as in the case of the insert 16, a slot 20 whose edges are parallel to the axis of the sleeve 14 and of the insert itself. In the variant of Figure 5, the insert 23 has a slot 24 whose edges are on the contrary oblique with respect to the axis of the insert.

In all cases, the metal insert can be economically produced from a thin sheet, for example from a sheet of mild steel. The manufacturing can be done by cutting and stamping a sidewall, the slit being produced as a last operation. It is also possible, in the case of an insert of simple cylindrical shape, without collar, as illustrated in FIGS. 4 and 5, making the insert by rolling a sheet of metal.

FIG. 2 illustrates an assembly intended for producing the declutching stop device, illustrated in FIG. 1, after mounting on the operating element 2. The identical elements, illustrated in FIG. 2, have the same references as on the FIG. 1. The rolling bearing 1 provided with its rings 11 and 7, forms an assembly with the elastic self-alignment sleeve 14 mounted in the bore 7a of the ring 7. The sleeve 14 comprises the metal insert 16, generally annular in shape and provided in the illustrated example with a radial flange 16a. The insert 16 has a slot filled with a bridge of synthetic material 21.

In this assembly, the elastic sleeve 14 is held at

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 the inside of the bore of the ring 7 by the two axial stops constituted, on the one hand by the radial flange 16a of the insert 16, and on the other hand by the bead 17. The assembly can be sold and transported in this form without risk of separation of its elements.

Figure 7 illustrates a clutch release device according to the invention, in which similar parts have the same references. In this embodiment, the rolling bearing 25 is of the conventional type and has solid rings whose final machining of the functional cylindrical parts is carried out by grinding. The inner ring 26 is in frictional contact through its radial end face 26a with a radial portion 3b of the operating element 3. The elastic self-alignment sleeve 14 has an insert 16 and has a structure similar to that of the embodiment illustrated in FIG. 1. It comprises in particular a plurality of self-aligning ribs 15 and is produced by overmolding inside the insert 16. The sleeve 14 is mounted with the metal insert 16 in direct contact with the rectified bore 26b of the non-rotating inner ring 26 of the bearing 25. The metal insert 16 has a slot similar to that of the embodiment illustrated in Figures 1, 2 and 3, said slot being filled of elastic synthetic material at the location of the slot 20 in the form of a trigger guard 21.

The rolling bearing 25 also has a rotating outer ring 27, on which is fixed a driving element 28 capable of coming into contact with the diaphragm of the clutch not illustrated in FIG. 7. The sealing lip 18 , integral with the elastic sleeve 14, also comes into contact with the internal face of the driving element 28. For the rest, the sealing of the rolling bearing 25 is ensured by two lateral seals 29 and 30 mounted between the two rings 26 and 27.

FIGS. 8 and 9 illustrate a resilient sleeve in section, comprising a cylindrical insert 22 identical to that which is illustrated in FIG. 4. FIGS. 8 and 9 show the material of the trigger guard 21 filling the slot 20.

It would also be possible as a variant not to provide an overmolding of synthetic material at the location of the slot of the insert. It is

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 which is illustrated in the enlarged sectional view of Figure 10, where the slot 20 of the insert 22 extends into the overmolded synthetic material of the sleeve 14, thus giving greater flexibility to said sleeve.

The present invention allows the use of self-aligning sleeves with metal inserts which are extremely compact and economical to manufacture, since they do not require high manufacturing precision. These self-aligning sleeves can be mounted very easily in the non-rotating ring of the rolling bearing of a declutching stop device, either with the press, or possibly by hand.

Such use is particularly advantageous in the case of bearing rings having wide manufacturing tolerances, such as rings made of stamped sheet metal.

The invention can also be applied in the case of conventional rings, having a rectified cylindrical bore.

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Claims (1)

 CLAIMS 1-Clutch release device of the type comprising, a rolling bearing provided with a rotating ring (11, 27) and a non-rotating ring (7, 26) and provided with a driving element ( 11b, 28) able to cooperate with a clutch diaphragm (13), an operating element (3) able to move axially in translation under the action of a control member (6), a car sleeve -alignment (14) radially elastic, mounted between the bore of the non-rotating ring (7, 26) and a bearing surface (3 a) of the operating element (3), said sleeve (14) comprising a metal insert (16) of generally annular shape and an elastic portion made of a synthetic material in contact with said bearing surface of the operating element, characterized in that the insert (16) has a slot (20) extending from the 'one of the axial faces of said insert to the opposite axial face. 2-A clutch release device according to claim 1, characterized in that the slot of the insert is parallel to the axis of the sleeve. 3-clutch release device according to claim 1, characterized in that the slot of the insert is oblique to the axis of the sleeve. 4-A clutch release device according to any one of the preceding claims, characterized in that the insert has a substantially radial flange (16a) cooperating with a front face of the non-rotating ring of the rolling bearing. 5-A clutch release device according to any one of the preceding claims, characterized in that the insert is in direct contact with the bore of the non-rotating ring of the rolling bearing. 6-Release clutch device according to any one of the preceding claims, characterized in that the external diameter of the sleeve in the free state, before its assembly, is greater than the diameter of the bore of the non-rotating ring of the rolling bearing. 7-clutch release device according to any one of the preceding claims, characterized in that the elastic portion <Desc / Clms Page number 13>  of the sleeve is interrupted at the location of the slot of the insert. 8-A clutch release device according to any one of claims 1 to 6, characterized in that the elastic portion of the sleeve fills the slot of the insert. 9-A clutch release device according to any one of claims 1 to 6, characterized in that the elastic portion of the sleeve has an axial retaining bead (17) cooperating with the non-rotating ring of the rolling bearing. 10-A clutch release device according to claim 9, characterized in that the elastic portion of the sleeve fills the slot of the insert, said bead being interrupted at the location of the slot of the insert. 11 -Disengagement stop device according to any one of the preceding claims, characterized in that the elastic portion of the sleeve is molded onto the insert. 12-clutch release device according to any one of the preceding claims, characterized in that the elastic portion of the sleeve has a plurality of internal ribs (15) of self-alignment inclined relative to the radial direction and section decreasing inward. 13-clutch release device according to any one of the preceding claims, characterized in that the rings of the rolling bearing are of pressed sheet metal, the attack element being constituted by a portion of the rotating ring, the ring non-rotating having a radial flange (7b) in frictional contact with a radial surface (15) of the operating element. 14-A clutch release device according to any one of claims 1 to 12, characterized in that the rolling bearing (25) is of conventional type and comprises solid rings with a rectified cylindrical bore, the element of attack (28) being fixed on the rotating ring. 15-A clutch release device according to any one of the preceding claims, characterized in that the elastic portion of the sleeve has a sealing lip (18) cooperating with the driving element. <Desc / Clms Page number 14>  16-Assembly intended for the production of a declutching stop device comprising, a rolling bearing provided with a rotating ring and a non-rotating ring and provided with an attack element capable of cooperating with a diaphragm clutch, a radially elastic self-aligning sleeve, mounted in the bore of the non-rotating ring, said sleeve comprising a metal insert of generally annular shape and an elastic portion made of a synthetic material, characterized in that the insert has a slot extending from one of the axial faces of said insert to the opposite axial face.