AU4752199A

AU4752199A - Foot(steady) bearing and a process for its manufacture

Info

Publication number: AU4752199A
Application number: AU47521/99A
Authority: AU
Inventors: Freudenberg Kg Carl
Original assignee: Carl Freudenberg KG
Current assignee: Carl Freudenberg KG
Priority date: 1998-09-11
Filing date: 1999-09-10
Publication date: 2000-03-16
Anticipated expiration: 2019-09-10
Also published as: BR9904133A; AU720404B2; DE19841882C1; HUP9903065A3; EP0985838A1; NO994383D0; NO994383L; ATE225909T1; TR199901790A1; DE59903007D1; PT985838E; HU9903065D0; CN1247808A; ES2183458T3; HUP9903065A2; PL335361A1; EP0985838B1; TW430609B; CA2282074A1; HU221937B1

Description

Our Ref: 730377 P/00/011 Regulation 3:2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT A

A

C

Applicant(s): Address for Service: Invention Title: Carl Freudenberg Hohnerweg 2-4 D-69469 Weinheim

GERMANY

DAVIES COLLISON CAVE Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 Foot(steady) bearing and a process for its manufacture The following statement is a full description of this invention, including the best method of performing it known to me:- 5020

TRANSLATION

Support Bearing and a Method for its Production S" Description 10 Technical Field The present invention pertains to a method for the production of a support bearing, comprising an inner ring which is enclosed by an outer ring arranged at a radial distance, where the inner and the outer ring are connected by a spacing ring made of an elastomeric (rubber elastic) material arranged in the gap formed by the clearance between the inner ring and the outer ring.

State of the Art Such a support bearing is known for instance from the German patent DE 20 61 625 B2. This prior art bearing is used as an intermediate (line shaft) bearing for Cardan shafts in vehicles, where the intermediate bearing is formed by several web elements made of elastomeric material arranged at equal distances from one another in circumferential direction. The web elements extend between the inner ring and the outer ring in radial direction seen in longitudinal as well as in cross-section, wherein there is arranged between all of the adjacent web elements spaced apart in circumferential direction a detent buffer, each of which is secured against the outer support ring and extends inwardly in radial direction and is arranged at a radial distance adjacent to the inner ring in the vibration-free state. It must be taken into consideration in this situation that the wearing quality of the previously known bearing during long operating periods is not very satisfactory. Following the production process and during custom applications of the bearing, tensile stresses occur within the spacing ring, consisting of web elements, which tensile stresses reduce the service life •and lead to premature failure of the bearing.

S" Description of the Invention The object of the present invention is to further develop a support ring and a method for its production in the manner mentioned at the outset in such a way that the 15 production-dependent spacing ring is free from tensile stresses even without calibration of the inner and/or outer ring.

This object is achieved according to the present invention by the characteristics of Claim 1 and by the characteristics of Claim 3. Advantageous further developments/embodiments are contained in the Claims referring to Claims 1 and 3.

In order to achieve the objects of the present invention, it is proposed that the inner ring and the outer ring be inserted into the vulcanisation tool with an axial offset corresponding to the shrinkage due to the production process, that the spacing ring is vulcanised by an axial offset to an assumed radial plane at an inclination to the inner and outer ring, that the vulcanised support bearing is removed from the vulcanisation tool and that the axial offset between inner and outer ring is completely compensated by the spacing ring, which has a production-dependent inclination, during its cooling and curing process due to its shrinkage. The spacing ring, which is produced by the method according to the invention is free from radial tensile stresses and therefore has invariably good wearing qualities during long operating periods. A productiondependent shrinkage of the spacing ring following the removal of the support bearing from the vulcanisation tool does not cause tensile stresses as occur in vulcanised spacing rings which are not inclined in axial direction and where the inner ring as well as the outer ring are arranged vis a vis each other without axial offset. Due to the shrinkage of the spacing ring, the axial offset of the inner ring and the outer ring towards each other is independently and completely compensated.

In the event the support bearing is used for instance as a Cardan shaft bearing in motor vehicles, the inner ring and the outer ring can be inserted into the vulcanisation tool with an axial offset of 0.1 to 0.5 mm. This offset is completely compensated by the *oeet[ shrinkage of the spacing ring following its vulcanisation so that the spacing ring, seen from the longitudinal section of the support bearing, extends radially between the inner and the outer ring. Since the spacing ring, due to the production-dependent process, does not have any service-life-reducing tensile stresses, a calibration of the inner and/or outer ring following vulcanisation is not required.

The size of the shrinkage is essentially dependent on the material used and on the thickness of the spacing ring material.

Furthermore, the invention relates to a support bearing, produced according to the above described method, comprising an inner ring which is enclosed by an outer ring at a radial distance, where the inner ring and the outer ring are connected by a spacing ring of elastomeric material arranged in the gap formed between them.

For the solution of the task it is proposed that the spacing ring seen in longitudinal section in its production-dependent state has a greater length than in its ready-to-use Sstate. Due to the production-dependent process, i.e. immediately following the removal of the support bearing from the vulcanisation tool prior to the cooling and curing of the spacing ring, the inner ring and the outer ring are offset to each other in axial direction and the spacing ring between the inner ring and the outer ring is inclined by the axial offset to an assumed radial plane. During cooling and curing of the spacing ring, the length of the spacing ring is reduced due to shrinkage until the spacing ring in 15 its ready-to-use, i.e. fully cooled and cured, state extends only in radial direction and is arranged on a radial plane with the inner ring and the outer ring.

In most applications it has proven advantageous if the ratio of the productiondependent length to the ready-to-use length is 1.05 to 1.15. Depending on the material used and the thickness of the component material this ensures that the spacing ring in the ready-to use-state is free from radial tensile stresses.

The spacing ring can be formed by at least two web elements arranged in circumferential direction, which web elements are separated by a circumferential distance, where the web elements are bounded in circumferential direction by front faces extending parallel to the front face of an adjacent web element, and where all front faces are designed essentially flat and inclined in the same sense of rotation, and where the inclination angle of the front faces, relative to the circumferential direction, is conformal and between 15 and 75°, preferably between 30 and 60°. Productiondependent tensile stresses which have a service-life-reducing effect on elastomeric materials are reliably prevented by such designs. A production-dependent shrinkage of the web elements durihg vulcanisation does [not]' cause tensile stresses but merely a relative rotation of the inner ring and the outer ring towards each other.

"10 With the aim of achieving simple manufacture and simple assembly of the support bearing it has proven advantageous, if the adjacent web elements are designed to merge with one another and are evenly distributed in circumferential direction. The outer ring can have at least one aperture which is penetrated by the material of the 1 spacing ring, whereas the material of the spacing ring merges on the side of the aperture turned away from the web elements. This has the advantage that a secure S- mechanical attachment of the spacing ring to the outer ring is achieved which is also maintained unchanged during long service periods.

To achieve an assembly of a small number of components which is particularly advantageous with regard to an economical production process, the web elements can have inner and outer holding surfaces in radial direction, where the inner holding surfaces are adhesively connected with the circumferential surface of the inner ring and the outer holding surfaces with the inner circumferential surface of the outer ring. The use of additional support and stiffening rings is thereby rendered unnecessary.

The German original is not in the negative.

To prevent mechanical overloading of the web elements, impact buffers can be provided on the front faces turned towards one another in the direction of the opposite front face. Great relative dislocations in radial and in circumferential direction of the inner ring and the outer ring to one another can be restricted by means of the impact buffers being arranged at the front faces, in which case the impact buffers on the side directed to the opposite surfaces preferably have a semi-spherical profile, so that a limit position absorption occurs upon the impact buffers making contact with the opposite o ^surface.

Brief Description of the Drawings The support bearing according to the present invention and the method claimed for its production will be further explained below with reference to the enclosed drawings.

15 These show embodiment examples of the support bearing by way of schematic drawings.

Figure 1 shows one view of a first embodiment example of the support bearing according to the present invention.

Figure 2 shows a section of the embodiment example shown in Figure 1 in the production-dependent state in a section along line A-A Figure 3 is the embodiment example shown in figure 2 in the ready-to-use state following complete cooling and curing of the spacing ring.

Figure 4 is a second embodiment example, similar to the embodiment example shown in Figure 1.

Description of the Invention The two embodiment'examples of the bearing are used for instance as lay shaft bearings for Cardan shafts in motor vehicles. The bearings comprise a particularly small number of components in their assembly, wherein the web elements 10, 11, 19, o 10 20 with their inner and outer holding surfaces 15, 16 are prevulcanised directly with the adjacent surfaces of inner ring 1 and outer ring 2. Inner ring 1 in this embodiment example is formed by the outer bearing shell of a roller bearing, whilst the outer ring 2 is defined as a support ring and in the first embodiment example can be pressed into a bearing pedestal.

Oo In the second embodiment example the outer ring 2 is encircled by a rubber track 23 on its outer circumference, where the rubber track 23 itself is for instance enclosed by a bearing pedestal after having been prestressed.

Figure 1 shows a spacing ring 4 which, with its inner holding surfaces 15 is laid against the circumferential surface 17 of the inner ring 1, and with its outer holding surface 16 is laid against the inner circumferential surface 18 of the outer ring 2, and in this embodiment example comprises four web elements 10, 11, 19, 20 evenly distributed in circumferential direction, which web elements with their front faces 12, 13, 21, 22 directed towards one another in circumferential direction each bound a clearance. The web elements 10, 11, 19, 20 are provided with essentially flat front faces 12, 13, 21, 22 all of which are inclined in the same sense of rotation, wherein the inclination angle 14 relative to the circumferential direction in this embodiment example is a conformal angle of 45 To limit the relative rotation of the inner and outer rings 1, 2 to one another, the front faces 12, 13, 21, 22 can be provided with impact buffers not shown here, which buffers are essentially perpendicular to the respective adjacent front faces.

Figures 2 and 3 each show a longitudinal section of a support bearing, wherein the •1 support bearing is shown in figure 2 in the production-dependent state and in Figure 3, by contrast, in the ready-to-use state.

Figure 2 shows clearly that the inner ring 1 and the outer ring 2 are arranged vis-a-vis one another by an axial offset 5. The axial offset 5 corresponds to the productiondependent shrinkage of the spacing ring 4 following its vulcanisation. In Figure 2, the 15 spacing ring is inclined by the axial offset 5 to an assumed radial plane 7, where the axial offset 5 as well as the inclination are exaggerated for the purposes of clarification.

!During the cooling and curing of the spacing ring 4, following the removal of the support bearing from the vulcanisation tool, the spacing ring 4 shrinks, during which shrinkage the production-dependent length 8 is reduced to the ready-to-use length 9.

Due to the web elements 10, 11, 19, 20 arranged in circumferential direction at the inclination angle 14 and the spacing ring 4 being without radial tensile stresses, the spacing ring 4 is free from service-life-reducing tensile stresses in all directions and shows constant good service qualities during a very long service life.

P:\WPDOCS\CMJ\COMPRISE 10/9/99 -8A- Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

g O*

«OO

Claims

1. Method for the production of a support bearing, comprising an inner ring which is enclosed by an outer ring arranged at a radial distance, where the inner ring and the outer ring are connected by a spacing ring made of an elastomeric (rubber elastic) material arranged in the gap formed by the clearance between said inner and outer rings, characterised in that said inner ring and said outer ring are inserted into a vulcanisation tool with an axial offset corresponding to the production-dependent shrinkage, 10 that the spacing ring is vulcanised by an axial offset to an assumed radial plane at an inclination to said inner and outer ring that said vulcanised support bearing is removed from said vulcanisation tool and that the axial offset between inner and outer ring is completely independently compensated by said spacing ring, which has a production-dependent inclination, during its cooling and curing process due to its shrinkage.

2. Method according to Claim 1, characterised in that said inner ring and said outer ring are inserted into said vulcanisation tool with an axial offset of 0.1 to 0.5 mm.

3. Support bearing according to one of Claims 1 or 2, comprising an inner ring which is enclosed by an outer ring arranged at a radial distance, where the inner ring and the outer ring are connected by a spacing ring made of an elastomeric material arranged in the gap formed by the clearance between said inner and outer rings, characterised in that said spacing ring seen in longitudinal section in its production-dependent state has a greater length than in its ready-to-use state.

4. Support bearing according to Claim 3, characterised in that the ratio of the production-dependent length to the ready-to-use length is 1.05 to 1.15. Support bearing according to Claims 3 or 4, characterised in that the spacing ring in the ready-to-use state is free from radial tensile stresses.

6. Support bearing according to one of the Claims 3 to 5, characterised in that the spacing ring is formed by at least two web elements (10,11,19,20) arranged in circumferential direction, which web elements are separated by a circumferential distance, that said web elements (10, 11, 19, 20) are bounded in circumferential direction by front faces (12,13,21,22) extending parallel to the .9 10 front face of an adjacent web element, and that all front faces (12,13,21,22) are designed essentially flat and that the inclination angle (14) of the front faces (12,13,21,22), relative to the circumferential direction, is conformal and between 15 and 750

7. Support bearing according to Claim 6, characterised in that the angle is 30 to 15 600.

8. Support bearing according to one of the Claims 6 or 7, characterised in that the web elements (10,11,19,20) are designed to merge with one another and are evenly distributed in circumferential direction.

9. Support bearing according to one of the Claims 6 to 8, characterised in that the web elements (10,11,19,20) have inner and outer holding surfaces (15,16) in radial direction, and that the inner holding surfaces (15) are adhesively connected with the circumferential surface (17) of the outer ring and the outer holding surfaces (16) with the inner circumferential surface (18) of the support ring. Translator's comment: according to the German description this should read "inner ring (2) Support bearing according to one of the Claims 6 to 9, characterised in that at least one of the front faces turned towards each other (12,13,21,22) are provided with a surface profile.

11. Support bearing according to Claim 10, characterised in that the surface profile is defined by projecting stop buffers in the direction of the opposite front face.

12. A support bearing substantially as hereinbefore described with reference to the drawings. DATED this 10th day of September, 1999 S O CARL FREUDENBERG By his Patent Attorneys DAVIES COLLISON CAVE o S S -4