WO2008025634A1

WO2008025634A1 - Release bearing guide structure

Info

Publication number: WO2008025634A1
Application number: PCT/EP2007/057960
Authority: WO
Inventors: Gerhard Prosch; Ludwig Winkelmann
Original assignee: Schaeffler Kg
Priority date: 2006-08-31
Filing date: 2007-08-01
Publication date: 2008-03-06
Also published as: DE102006040973A1

Abstract

A release bearing guide structure comprises a sleeve body (3) which is composed of a plastic material and which has a bearing connection region provided for connecting a release bearing (2), and a guide bush section (3a) as a constituent part of the sleeve body (3), which guide bush section (3a) has an inner face (I) which functions as a guide face and which extends between a front end edge (4) and a rear end edge (5) and which has an axial region (A) which is surrounded by the release bearing (2). The sleeve body (3) has a reinforcement element (6) which is designed as a cage bush which is embedded at least in sections into the guide bush section (3a). The reinforcement element (6) and the sleeve body (3) are designed so as to be coordinated with one another in such a way that the reinforcement element (6) is embedded, at least in the axial region (A) surrounded by the release bearing (2), into an outer ring casing section (Ra) and into an inner ring casing section (Ri) of the sleeve body (3). This permits a release bearing guide structure which is cost-effective to produce and whose functionally relevant dimensions can be maintained in a narrow tolerance range in a reliably manageable way in terms of production.

Description

Name of the invention

Release bearing guide structure

description

Field of the invention

The invention relates to a release bearing guide structure, in particular for a clutch release bearing of a motor vehicle Schaltgethebes, said Ausrücklager- guide structure comprises a sleeve body, which carries as such a clutch release bearing and axially displaceable on an example mounted on the transmission side and surrounding a transmission input shaft guide pin.

Background of the invention

From DE 103 56 236 A1 discloses a release bearing guide structure of the aforementioned type is known, which has as such a sleeve body. The sleeve body comprises an inner wall which acts as a sliding guide surface and supports the sleeve body axially displaceable on a guide pin mounted on the transmission side. The sleeve body is made of a plastic material and provided with a Ringflanschabschnitt. On this annular flange portion of the sleeve body, a ring element is placed while leaving a movement play, which is made of a sheet metal material and carries a designed as a rolling bearing clutch release bearing.

From US PS 4,351,427 a clutch release bearing device is known, which as such comprises a designed as a rolling bearing clutch release bearing and a release bearing bearing this guide structure. The guide structure comprises a sleeve-like and made of a plastic material Guide cylinder. In this guide cylinder, a retaining ring is used which provides a seat on which the aforementioned clutch release bearing can be fixed.

Object of the invention

The invention has for its object to provide a release bearing guide structure, which is characterized by advantageous structural mechanical properties, is inexpensive to produce and their functionally relevant dimensions can be met in a tight tolerance tolerable in manufacturing technology reliably controllable manner.

Inventive solution

This object is achieved according to the invention by a release bearing guide structure comprising a sleeve body of a plastic material which comprises a bearing connection area provided for the connection of a release bearing, and a guide bush portion which forms a part of the sleeve body and has an inner surface functioning as a guide surface, which is between a front end edge and a rear end edge and having an encompassed by the Ausrücklager axial region, said Ausrücklager guide structure is characterized in that the sleeve body comprises a reinforcing element, which is designed as a cage bush, which is at least partially embedded in the guide bush portion, wherein the Reinforcing element and the sleeve body are designed coordinated with each other, that the reinforcing element at least in the encompassed by the release bearing axial region in an outer R ingmantelabschnitt and is embedded in an inner annular shell portion of the sleeve body.

This makes possible a release bearing guide structure whose longitudinal guide surfaces and their seating surfaces provided for positioning the release bearing can be produced as part of a plastic injection step. NEN, wherein the guide device is characterized by a high dimensional stability and also under extremely small dimensional and dimensional tolerances, in particular with regard to the bore diameter, process reliable.

According to a preferred embodiment of the invention, the cage bushing is made of a metal material, in particular steel sheet. In the manufacture of the basket bushing from a sheet metal material, it is possible to make it by means of deep drawing forming as seamless, i. to produce a consistent structure in the perimeter. Alternatively, it is also possible to manufacture the cage bushing from a sheet metal material as part of a winding or roll forming operation, and as a bearing cage by an axial seam or other, tensile forces receiving connection structures such. Claw structures or by clinching close. It is also possible to assemble the cage bushing from a plurality of segments or axial sections, in particular ring sections.

According to a preferred embodiment of the invention, the cage bushing is designed such that it has numerous openings through which the separated by the sleeve body plastic material zones of the guide bushing portion are interconnected. As a result, a particularly reliable adhesion of the Gleitführungsinnenfläche defining plastic material is ensured on the inner wall of the cage bushing. Furthermore, this also promotes the Anspritzvorgang of the plastic material.

The openings may be designed as substantially circular openings. It is also possible to design the contour of the apertures, and in particular also the geometry of the material sections skirting the respective apertures, in such a way that the mechanical properties of the female receptacle are thereby improved. In particular, it is possible to provide those wall areas skirting the openings with a small bead, so that the cage bush is locally stiffened by these beads. The openings can also be designed so that the corresponding material zones are not completely separated from the reinforcing element, but only be unlatched so far that a passage opening is formed, but otherwise the corresponding material sections continue to remain on the cage bushing. The openings can be provided with broken or rounded edges. As a result, a reduction in the notch stress load is advantageously achieved in the plastic material receiving the basket bushing.

The supporting shoulder structure projecting outwardly in the area of the annular flange is preferably designed such that the projection over the outer circumferential surface of the cage bushing amounts to at least 30% of the radial projection of the outer circumferential area of the annular flange via the cage bushing. This makes it possible to increase the axial load capacity of the transition region between the guide bush portion and the annular flange.

The support shoulder structure may be formed so that it is either completely embedded in the plastic material forming the annular flange or forms an annular wall exposed at least in sections on one or both sides. Furthermore, it is possible to form the support shoulder structure in such a way that it comprises laterally outwardly extending claw or staple or other fastening or actuating members, in particular actuating arms.

It is also possible to carry out the support shoulder structure as an annular bead. Such an annular bead can be brought about in particular by a crimp-compression forming, wherein initially at the corresponding area of the

Is formed by a bead forming a bulging outward peripheral bead. The thus pre-shaped cage bushing can be subsequently compressed or doubled in a corresponding die until the inner surfaces of that peripheral bead sit on one another as flat annular disk sections. It is also possible, the reinforcing element of a plurality of shells and / or ring sections, in particular at least two form, force or to assemble cohesive interconnected metal jacket elements.

As an alternative to the aforementioned embodiment of the support shoulder structure as annular bead, it is also possible to manufacture the support shoulder structure by a plurality of notches folded out radially outwards. These notches can be contoured so that the power transmission capacity between the cage bushing and provided for forming the annular flange plastic material is particularly favored by this.

It is possible to make the outer surface of the cage bushing so that it promotes the adhesion of the plastic material to the cage bushing. In particular, it is possible to roughen the outer surface of the cage bushing by a blast treatment, by applying an adhesion promoter, by metal spraying or etching and to increase the adhesion of the plastic material to the cage bushing.

The sleeve body, in particular the inner circumferential wall consisting of plastic, can be designed so that its inner surface, which acts as a guide surface, is designed as a substantially circular-cylindrical surface. Alternatively, it is also possible to make the inner surface so that it acts as a longitudinal guide surface, which allows a linear movement of the sleeve body, but prevents a rotation of the same. For this purpose, the inner surface can be embodied in particular as a toothed surface which, for example, is designed in terms of its geometry like a splined tooth structure.

On the sleeve body designed according to the invention, a further ring element can be attached to the support shoulder structure, which as such provides a carrier structure for a clutch release bearing. This ring element may in particular be connected to the support shoulder structure by means of, for example, positive embossing or crimping as part of a production step following the manufacture of the sleeve body. Alternatively, it is also possible spend this ring element together with the designed as a cage bushing reinforcing element in a plastic injection molding tool and to connect with each other via a subsequent plastic injection step.

The plastic material used is preferably a high mechanical and thermal strength plastic material. It is possible to add to this plastic material aggregate, lubricants, Gleitgranulat-, anti-corrosion and other fillers, which improve as such, the mechanical properties of the correspondingly formed composite component. It is also possible to manufacture the plastic body from a plurality of material mixtures which are different in their properties and injected at correspondingly different locations.

The apertures are preferably arranged in the circumferential direction with the same pitch or with a different spacing system. The openings may be formed in a plurality of axially spaced annular paths. The openings of the adjacent ring tracks may be offset from each other in the circumferential direction. The minimum cross section of the openings is preferably at least 3 mm ² . The openings can be made with rounded or broken hole edges in order to reduce the notch load of the embedding matehal. The plastic body is preferably molded onto the reinforcing element by an insert-molding injection method.

Brief description of the drawings

Further details and features of the invention will become apparent from the following description taken in conjunction with the drawings. The drawing shows in: 1a, 1b each show an axial sectional view for explaining the structure of two variants of a clutch release bearing with a release bearing guide structure according to the invention;

FIGS. 2 a, 2 b show an axial sectional view for illustrating the

Structure of the release bearing guide structure in that release bearing of Figure 1 a and Figure 1 b;

FIG. 3 a shows an axial sectional view for further illustration of the reinforcing element of the release bearing guide structure according to FIG. 2, designed as a cage bush;

FIG. 3b shows a detailed representation to illustrate further details of embodiment variants of the release bearing guide structure according to FIG. 3a;

FIG. 3c shows a further detailed illustration to illustrate further details of the release bearing guide structure according to FIG. 3a;

Figure 4 is an axial sectional view through a further variant of a clutch release bearing with a release bearing guide structure according to the invention, as they can be used advantageously in commercial vehicles application;

Figure 5 is a detail view illustrating a Ausklinkschulter variant of the cage bush according to the invention; and in

Figure 6 is a detailed view illustrating a Ringwulst variant of the cage bush according to the invention. Detailed description of the drawings

FIG. 1 a shows a release bearing guide structure 1 including a release bearing 2 supported by it. The release bearing 2 comprises a bearing outer ring 2a and a bearing inner race 2b. The release bearing 2 shown here is connected via those outer ring 2a indirectly via an inner biasing spring 20 and a support ring 10 to the release bearing guide structure 1.

The release bearing guide structure 1 comprises a sleeve body 3, which is made of a plastic material. The sleeve body 3 in turn comprises a guide bush portion 3a which forms part of the plastic body and comprises an inner surface I acting as a guide surface, which extends between a front end edge 4 and a rear end edge 5, and comprises an axial region A encompassed by the release bearing.

The release bearing guide structure 1 shown here is characterized in that the sleeve body 3 comprises a reinforcing element 6, which is designed as a cage bushing which is at least partially embedded in the guide bushing section 3a, wherein the reinforcing element 6 and the sleeve body 3 are designed coordinated with each other, the reinforcing element 6 is embedded at least in the axial region A encompassed by the release bearing 2 into an outer annular sheath portion Ra and into an inner annular sheath portion Ri of the sleeve body.

In this exemplary embodiment, the reinforcing element 6 is also designed in such a way that, in an axial region adjacent to an annular flange 3b, it forms an outwardly projecting support shoulder structure 7.

The running as a basket bushing reinforcing element 6 is in the embodiment shown here of a metal material, in particular a Made of steel material and designed as a hoop-proof closed structure.

The reinforcing element 6 designed as a basket bushing has a plurality of openings 8, 9. About these breakthroughs separated by the bushing plastic material zones of the guide bushing portion 3a are interconnected. About the openings 8, 9 so that the inner wall I forming inner region of the plastic body is positively anchored to the cage bushing. The sleeve body is produced by umsphtzen the reinforcing element 6.

On the basis of the design concept for a release bearing guide structure shown here, it is possible to ensure process tolerances in the area of the inner surface I in a process area of less than 0.1 mm in plastic construction. In addition, based on the concept shown here, in particular in combination with the support ring 10, a particularly high rigidity of the release bearing guide structure in the axial direction results. The sleeve body 3 according to the invention consists of an at least partially encapsulated and made of sheet steel reinforcing element. This reinforcing element is encapsulated by a plastic material. The thickness of the wall formed by the plastic material within the cage bushing is preferably at least 0, 8 mm. By formed in the region of the cage bushing openings 8, 9, the flow around and flow around the reinforcing element 6 is supported during the plastic injection process.

The reinforcing element 6 according to the invention preferably extends at least almost over the entire axial length of the sleeve body 3. The reinforcing element 6 can also be used to realize edge end structures of the sleeve body, in particular, end ring structures. The reinforcing element 6 according to the invention advantageously counteracts a change in diameter in the region of the inner surface I due to shrinkage effects of the plastic material. Furthermore, by these openings 8, 9 allows a firm grip of the reinforcing element 6 through the plastic material.

In the embodiment shown in Figure 1 a of the annular flange 3b is formed such that its axial length is about 30% of the axial length of the guide bush portion 3a. In the embodiment shown here, the axial length of the annular flange section 3b is less than 40% of the axial length of the guide bushing section 3a.

On the annular flange portion 3b and on this upstream outer surface portion of the guide bush portion 3a, a support ring 10 is optionally placed with axial and radial play. At this support ring 10, the outer ring 2a of the release bearing 2 is secured by an inner biasing spring 20. The support ring 10 can be secured to the sleeve body 3, in particular the support shoulder structure, by latching means (not illustrated here).

The embodiment variant according to FIG. 1 b differs from the embodiment variant according to FIG. 1 a with regard to the configuration of the sleeve body 3. In the embodiment according to FIG. 1 b, the guide bush section 3 a has a constant radial in the region between the front end edge 4 and the support shoulder structure 7 Jacket thickness on. The annular flange section 3b is omitted, so that the support shoulder structure is exposed on both sides. Otherwise, the comments on the variant of Figure 1 a mutatis mutandis.

In Figure 2a, the sleeve body 3 of the release bearing guide structure of Figure 1 a is shown again. The sleeve body 3 consists, as already explained, of the guide bush portion 3a, the annular flange 3b and at least partially embedded in the guide bushing portion 3a reinforcing element 6, which is designed as such as a cage bushing and several perforations 8, 9 and has almost over the entire length of the guide bush portion extends. The reinforcing element 6 has a support shoulder structure 7, which extends in this embodiment along a radial surface of the annular flange 3b. In the region of the guide bush section 3a which is located upstream of the annular flange 3b, the reinforcing element 6 is completely embedded in the other plastic material forming the sleeve body 3. As a result, both the inner surface I and the outer surface A of that portion of the guide bush section 3a upstream of the annular flange 3b are formed by the plastic material provided for forming the sleeve body. The embedding of the reinforcing element 6 in the otherwise recognizable sleeve body takes place in the context of an insert molding process in a corresponding injection molding machine.

In Figure 2b, the sleeve body 3 of the release bearing guide structure of Figure 1 b is shown again. The cage bushing is completely embedded in the plastic body forming the guide bushing section 3a in the axial region lying between the front end edge 4 and the support shoulder structure 7 and is thus located between an inner and an outer annular skirt section Ra, or Ri.

In FIG. 3 a, the inventive reinforcement element 6 is shown in the form of a simplified axial section. This reinforcing element 6 comprises the cage bush area 6a provided for embedding in the guide bush section 3a (see FIG. 2) and the radially protruding support shoulder structure 7. In the exemplary embodiment shown here, the support shoulder structure 7 is located in the region of a rear end edge of the cage bush section 6a. The basket bushing portion 6a is, as clearly shown in this illustration, provided with the already mentioned openings 8, 9, through which a particularly effective anchoring of the formation of the guide bushing section 3a otherwise still required plastic material on the reinforcing element 6 can be realized. The perforations 8, 9 are formed at the same pitch and the same circumferential angular position in the region of the reinforcing element, which reinforces the guide bush section 3a. FIGS. 3b and 3c show a special design of the guide bush section 3a. According to these two representations, longitudinal grooves 3c are provided in the region of the inner surface of the guide bush section 3a, by means of which the otherwise cylindrical inner surface I of the guide bush section 3a is subdivided into a plurality of longitudinal segments F. The arrangement of those longitudinal grooves 3 c is made such that they extend between the openings 8, 9. Due to the formation of those longitudinal grooves 3 c, it is possible to substantially completely prevent a change in the diameter of the cylinder defined by the inner surface I due to shrinkage expansion phenomena of the processed plastic matehal and to create a certain compensation space in the circumferential direction in the immediate vicinity of the guide surface.

As an alternative to the Anspritzvariante shown here, the guide bush sections can also be designed as a single, or multiply connected strips and are fixed to the reinforcing element 6 positive, non-positive or cohesive.

FIG. 4 shows a further variant of a release bearing guide structure according to the invention which, similar to the guide structures described above, comprises a sleeve body 3 made of a plastic material, this sleeve body comprising a guide bushing section 3a in which a reinforcing element 6 designed as a cage bushing is embedded is. In this exemplary embodiment as well, a plurality of axial grooves 3c extending in the axial direction are formed in the region of the guide bush section 3a, by means of which a compensating space contributing to compensate for any volume changes of the plastic matehal is provided in the immediate vicinity of the guide surface defined by the inner wall I. It is possible to realize an anti-rotation lock via these axial grooves 3c.

The reinforcing element 6 is provided with a support shoulder structure 7 in the region of a front end facing away from the release bearing 2. These support Shoulder structure extends in the immediate vicinity of an integrally formed with the guide bush portion 3a annular flange 3b. By the support shoulder structure 7, the axial load capacity of a created in conjunction with the annular flange 3b axial securing is increased.

FIG. 5 shows a further variant of a release bearing guide structure 1 according to the invention. In this embodiment, the reinforcing element 6 is embedded as completely in the otherwise forming the sleeve body plastic material. The reinforcing element 6 is also designed in this embodiment as a cage bushing, which has numerous apertures 8, 9, via which a positive anchoring of the plastic matehale on the reinforcing element 6 is made possible.

The release bearing guide structure shown here is also characterized in particular by the fact that the support shoulder structure 7 formed on the reinforcement element 6 and projecting radially outwards is realized by notching a corresponding section of the peripheral wall of the cage bushing. By the embodiment of the reinforcing element 6 shown here, the annular flange 3b of the sleeve body 3 is stiffened from the inside out by the Stützschulter- structure 7. The radial projection of the support shoulder structure 7 over the outer peripheral surface of the cage bush in the region of the guide bush portion 3a is about 50% of the difference between the outer radius of the annular flange 3b and the outer radius of the guide bush portion 3a.

6 shows a further variant of a Ausrücklager- guide structure according to the invention is shown, in which the reinforcing element 6 is again designed as a cage bushing, which is completely embedded in the intended to form the sleeve body plastic material. On the reinforcing element 6 also a radially outwardly projecting Stützschulterstruk- is formed 7. This support shoulder structure 7 is embodied as a circumferential bead or doubling, which is produced by a crimping 7 compression forming process. The reinforcing element can also be made of two sections, which are connected for example by resistance welding. For the production of the release bearing guide structure shown here, a reinforcing element designed according to the invention as a cage bushing is inserted into a corresponding molding tool of an insert molding spraying machine. After closing the mold, plastic material is injected into a molding space formed therein. Here, the reinforcing element, as shown, embedded in the otherwise forming the sleeve body plastic material. The outer dimensions of the sleeve body thus created are determined by the geometry of the molding tool. Inadmissibly strong deviations in shape and changes of the sleeve body due to special material properties of the plastic material used are largely suppressed by the embedded reinforcing element.

The basket bushing can also be manufactured as a molded part, in particular as an aluminum injection-molded part or also from a fiber-reinforced plastic material. The openings can also be designed as depressions with lateral slot openings. The support shoulder structure 7 may also be formed by a first separately manufactured component, which is connected to the cage bushing.

Claims

claims

1. release bearing guide structure, comprising a sleeve body (3) made of a plastic material which has a bearing connection area for connection to a release bearing (2), and a guide bush portion (3a) as part of the sleeve body (3), which acts as a guide surface inner surface (3) I) which extends between a front end edge (4) and a rear end edge (5) and has an axial region (A) encompassed by the release bearing (2), characterized in that the sleeve body (3) has a reinforcing element (6). which is designed as a cage bushing, which is at least partially embedded in the guide bushing portion (3a), wherein the reinforcing element (6) and the sleeve body (3) are designed coordinated with each other, that the reinforcing element (6) at least in that of the release bearing (2) encompassed axial region (A) in an outer annular shell portion (Ra) and in an i nneren annular sheath portion (Ri) of the sleeve body (3) is embedded.

2. Release bearing guide structure according to claim 1, characterized in that the cage bush is made of a metal material.

3. release bearing guide structure according to claim 1, characterized in that the cage bushing is designed as a continuous structure in Umfangsgehchtung.

4. release bearing guide structure according to claim 1, characterized in that the cage bush is designed as a deep-drawn part.

5. release bearing guide structure according to claim 2, characterized in that the cage bush made of a strip material wound and with an axial seam or otherwise material, positive or non-positive connection structure is provided.

6. clutch release bearing guide structure according to claim 1, characterized in that the cage bushing has a plurality of openings (8, 9) over which in the wrapper of the rolling bearing (2) separated by the cage bushing inner and outer plastic material zones (Ra, Ri) of the guide bush portion ( 3a) are interconnected.

7. release bearing guide structure according to claim 6, characterized in that the openings (8, 9) are designed such that is stiffened by this the cage bushing in Durchbrechungsrandbereich.

8. Ausrücklager-guide structure according to claim 1, characterized in that it comprises an annular flange (3b) which also forms part of the sleeve body (3) and the guide sleeve portion (3a) surrounds, wherein on the reinforcing element (6) in one with the annular flange ( 3b) is formed or this adjacent axial region a radially outwardly projecting support shoulder structure (7) is formed.

9. Ausrücklager-guide structure according to claim 8, characterized in that the support shoulder structure (7) is formed such that the supernatant of the same over the outer trapping surface of the cage bushing at least 30% of the measure of the radial projection of the outer peripheral surface of the annular flange (3b) over the Basket bush amounts.

10. release bearing guide structure according to claim 8, characterized in that the support shoulder structure (7) is designed as an annular wall.

11. Release bearing guide structure according to claim 8, characterized in that the support shoulder structure (7) is formed by an annular bead.

12. release bearing guide structure according to claim 8, characterized in that the support shoulder structure (7) is made by a plurality of radially outwardly unfolded notches.

13. Release bearing guide structure according to claim 1, characterized in that the support shoulder structure in the annular flange (3b) is embedded.

14. release bearing guide structure according to claim 1, characterized in that the outer surface of the cage bushing is provided with a primer coating and / or a roughened surface which increases the material adhesion of the Kunststoffmatehales to the cage bushing.