WO2006117140A2

WO2006117140A2 - Connecting arrangement between a roller and clamping device

Info

Publication number: WO2006117140A2
Application number: PCT/EP2006/003960
Authority: WO
Inventors: Johann Singer; Christian Krüger
Original assignee: Schaeffler Kg
Priority date: 2005-05-03
Filing date: 2006-04-28
Publication date: 2006-11-09
Also published as: WO2006117140A3; DE102005020530A1

Abstract

The invention relates to a connecting arrangement between a roller (1) for belt means and a clamping device (2), wherein the roller (1) is supported by at least one roller bearing (8) which comprises inner and outer rings (8a, 8b) and a roller body (8c) arranged therebetween. The inner ring (8a) of the roller bearing(s) rests, at least indirectly, on a bearing pin (9) in such a way that a swivel arm (5) of the clamping device is freely projected and is axially pressed against a radial connecting element (15) of the swivel arm (5) by means of a front-engageable nut (14) which can be screwed from the free end of the bearing pin (9) on a part of a threaded section thereof and forms a thread thereon during screwing, thereby making it possible to carry out the simple and cost-effective mounting and dismounting of the roller bearing (8), including the roller (1), on the bearing pin (9).

Description

Name of the invention

Connecting arrangement between a roller and a tensioning device

description

Field of the invention

The invention relates to a connection arrangement between a roller and a tensioning device for a belt, wherein the roller of at least one, an inner and an outer ring and rolling elements arranged therebetween bearing is supported.

Background of the invention

Connecting arrangements between a roller and a tensioning device, in particular a tensioning device for bracing a wrap-around means, such as a wedge or toothed belt in the drive arrangement of a motor vehicle, are known in the most varied embodiments.

Thus, from DE 23 43 748 A1 discloses a so-called bearing plate for pivotally mounting a mounted on this roller, in which the inner ring of a rolling bearing is fixed to a hollow cylindrical protuberance of the bearing plate by press fit. Furthermore, it is proposed in this document to provide the free end of the hollow cylindrical protuberance with a flange. Although this solution for fastening a roller to the hollow-cylindrical protuberance of the bearing plate may fulfill its purpose, it can be estimated to be complicated and cost-intensive. Furthermore, a release of the roller from the bearing plate due to, for example, a bearing damage without damaging the hollow cylindrical protuberance is hardly reach, so that in case of damage not only the rolling bearing, but at least the bearing plate is replaced.

DE 38 36 933 A1 discloses a tensioning device in which the roller bearing of a roller is secured axially by means of a separate fastening means, in the present case a snap ring, which engages in a groove of a bearing pin integrally formed with a pivoting arm. This type of attachment of the roller is also complicated and expensive, since a groove for receiving said snap ring must be created here.

In DE 101 27 521 A1 discloses a pivot bearing for a clamping device is disclosed in which a fastening screw is provided as fastening means for fastening the roller on a integrally formed with a pivot arm bearing pin, which in turn is screwed within the axis of rotation of the roller. Due to the minimum support length and the position of the stress concentration of the screw thread Mindestschraubenlän- gene or minimum Schwenkarmdicken required, on the one hand lead to increased accumulation of material in the tapping area and on the other to an increased envelope geometry of the clamping device, whereby the arrangement in the area, for example a motor is restricted. Incidentally, a screw connection does not allow arbitrarily small pivot arms. Finally, there are also increased costs for the production of the bore and the internal thread recorded. Even if a self-tapping screw is used, the cost of making the hole remains. Furthermore, high accuracy requirements have to be placed on the named screw and the screw hole as well as on the required mounting device.

Object of the invention

The invention has for its object to provide an improved connection arrangement of the generic type, which is feasible with the lowest possible number of components with the simplest measures and accordingly with low mechanical complexity and expenditure of time and a allows easy replacement of the roller or roller bearing, without the swing arm itself being affected.

Summary of the invention

The invention is based on the finding that conventional connection arrangements between a roller and a tensioning device are expensive to manufacture and thus cost-intensive.

In order to counter this situation effectively, the object is achieved according to the features of the main claim, starting from a connection arrangement between a roller and a tensioning device for a belt, in which the roller of at least one, an inner ring and an outer ring and arranged therebetween rolling elements Rolling is supported, achieved in that the inner ring of the at least one rolling bearing is supported radially at least indirectly on a cantilevered journal of a pivoting arm of the clamping device and axially by means of a screwed from the free end of the journal forth on a gland and frontally engaging thread-forming nut against a Radial web of the swivel arm is stretched.

By this measure, a cost reduction is realized such that conventional measures for creating a screw hole and a thread produced separately are avoided. The significantly reduced in terms of screws fastener "thread-forming nut" allows easy mounting of the rolling bearing together with the roller on the pivot arm of the clamping device, since the external thread on the threaded portion of the journal does not need to be prepared in advance, but with the screwing the nut on the journal in a work step takes place. Likewise, a simple removal of the rolling bearing and roller from the journal is ensured by only the thread-rolling nut is released. Thread-forming nuts are in a particularly advantageous manner re-screwed several times, since the thread in the journal is pushed in, so to speak, and accordingly no chip formation is recorded. An additional retaining ring can be largely dispensed with, since a high vibration safety is provided solely by the thread friction of the thread-rolling nut.

The subclaims describe preferred developments or refinements of the invention.

Thereafter, it is proposed according to a first preferred embodiment of the invention that the threaded bore of the thread-rolling nut in cross-section has the shape of a polygon with three or more inwardly rounded form webs, the thread with a largely cylindrical bearing pin is engageable.

In contrast, according to a second preferred embodiment of the invention, the threaded bore of the self-tapping nut is cylindrical in cross-section and engageable with a bearing pin, the cross-section of which has the shape of a polygon with three or more outwardly rounded forming webs.

The threaded bore of the thread-rolling nut or said bearing journal preferably have a trilobular shape in cross-section, the thread of the nut being provided with a radius profiling. This results in a significant reduction of the torques or the torques. Low torques and high over torques (failure torques) lead advantageously to a high biasing force or high clamping forces.

In a further development of the invention, it is provided that the inner ring of the rolling bearing is supported radially on a support portion of the journal, which adjoins in the axial direction directly to the radial web of the pivot arm and is chosen to be larger in diameter than the screw portion of the journal. Likewise, the thread-forming nut next to a radial flange portion having an axially oriented support portion on which the inner ring of the rolling bearing is radially supported.

It is further proposed that the projecting into the bore of the inner ring of the bearing bearing portion of the journal and / or the support portion of the thread-forming nut are tapered conical, whereby an improved assembly is permitted.

The pivoting arm together with a bearing pin formed integrally therewith is preferably made of cast metal, with light-weight cast metal, such as die-cast aluminum, being particularly favored.

The thread-rolling nut is preferably made of tool steel, whereby the required material pairing of a hard and a soft partner for threading grooves is given.

As the invention also provides, the radial flange portion of the thread-rolling nut can be formed so enlarged radially that a front-side contamination protection of the rolling bearing is realized.

The invention also includes a self-tapping nut per se for positive and non-positive and releasable connection with a cylindrical bearing pin or journal whose threaded bore has in cross-section the shape of a polygon with three or more inwardly rounded molding webs.

Although a thread-forming screw is known in the art, a thread-rolling nut capable of engaging with any pin member as a result of a thread being threaded thereinto into a positive and non-positive and releasable connection has heretofore remained unknown. The threaded bore of the thread-rolling nut preferably has a Tri lobular shape in cross-section, wherein the thread thereof is provided with a radius profiling.

Brief description of the drawings

The invention will be explained in more detail below with reference to the accompanying drawings of some embodiments. Show in it

1 is a sectional view of a conventional connection arrangement between a roller and a tensioning device for bracing a belt according to the prior art,

Fig. 2 shows a first embodiment of an inventively designed connection arrangement between a roller and a tensioning device, and

Fig. 3 shows a second embodiment of the connection arrangement.

Detailed description of the drawings

1 thus shows a conventional connection arrangement between a roller 1 and a tensioning device 2, for example for bracing a belt means of a drive arrangement of a motor vehicle not shown in greater detail.

In the present case, the clamping device 2 has a rotationally symmetrical basic element 3, which is connected by means of a screw, not shown, to a rotationally symmetrical receiving element 4 for a swivel arm 5 and attached to a load-bearing component of the motor vehicle body or to the housing of an internal combustion engine or a transmission. bar is. The pivot arm 5 is in turn rotatably mounted on a slide bearing 6 on the outer contour of the receiving element 4.

Furthermore, the pivot arm 5 is acted upon by a torsion spring 7, which is supported at one end on the base element 3 and the other end on the pivot arm 5, with a torque such that the roller 1 is pressed against the belt, not shown, and this clamped as intended.

As shown in FIG. 1 further, the roller 1 is rotatably mounted on an associated roller bearing 8 on an integrally formed with the pivot arm 5 cantilevered bearing pin 9 and by means of an axially not shown here by the inner ring of the rolling bearing 8 and in a threaded bore 10 of the Bearing 9 engaging fastening screw 11, with, for example, a Torx receptacle for a suitable tool, fixed to the pivot arm 5.

In the present case pivot arm 5 and bearing pin 9 are integrally made of a cast material. Axially outward, a cover cap 12 is fastened to the roller 1 to protect the roller bearing 8 against soiling and damage.

The described attachment of the roller 1 on the pivot arm 5 of the clamping device 2 is expensive and therefore costly, since on the one hand, the components to be joined must have a high dimensional accuracy and on the other an increased accumulation of material on the pivot arm 5 to be created with increased time and cost tapping 10 must be provided.

The inventively designed connection arrangement of FIG. 2 differs essentially to the prior art described above in that the rolling bearing 8, consisting of inner and outer ring 8 a, 8 b and disposed therebetween rolling elements 8 c, over the Inner ring 8 a radially on the cantilevered bearing pin 9 of the pivot arm 5 of the clamping device 2 is supported and axially by means of a forth from the free end of the bearing pin 9 forth on a screw 13 of the same screwed and frontally engaging thread-forming nut 14 against a radial web 15 of the swing arm 5 is stretched ,

It will be readily apparent to those skilled in the art that the conventionally required accumulation of material in the region of the radial web 15 of the swivel arm 5 is now unnecessary and the swivel arm 5 itself accordingly builds lighter and more space-saving.

In an inventive approach to known and thus not to be shown thread-forming screws, the threaded bore of the thread-forming nut 14 while maintaining the action mechanisms of thread-forming screws in cross-section in the shape of a polygon with three or more inwardly rounded form webs whose thread with a widest going cylindrically shaped bearing pin 9 can be brought into engagement (not shown in detail).

In contrast, the screw shaft of conventional thread-forming screws is provided with a cross-section, which has the shape of a polygon with three outwardly rounded mold lands, so in cross-section a so-called trilobular shape.

Preferably, the threaded bore of the self-tapping nut 14 also has a trilobular shape in cross-section, however, as already mentioned, with inwardly rounded forming webs, wherein a radius profiling of the thread is provided.

Radius profiling itself have become known in connection with self-tapping screws, so far in a known so-called Taptite ^® - and duo Taptite ^® screws is referenced. FIG. 2 furthermore shows that the inner ring 8a of the rolling bearing 8 is supported radially on a support section 16 of the bearing journal 9. This support section 16 adjoins the radial web 15 of the swivel arm 5 in the axial direction and is chosen to be larger in diameter than the screw connection section 13 of the journal 9.

Regardless of this, it is now possible to influence the load capacity or safety of the screw with simple measures on the choice of the diameter of the screwing and thus the thread of the thread-rolling nut 14.

The embodiment according to FIG. 3 differs from the previously described variant in that the thread-rolling nut 14 has, in addition to the radial flange section 17 which is conventional per se, an axially oriented support section 18 which extends into the bore of the inner ring 8a and over which the inner ring 8a of the Rolling 8 directly supported on the bearing pin 9. As a result, a structure is realized, which allows screwing the nut 14 together with the roller bearing 8 and the roller 1 as a pre-assembled component to the bearing pin 9.

Also possible is a combination of an inner ring 8a directly supporting support portion 16 of the bearing pin 9 and the said support portion 18 of the thread-forming nut 14 (not shown in detail).

For improved assembly of the rolling bearing 8, it may also be indicated, one or both support portions 16, 18 conically tapered form.

As already briefly indicated above, the pivoting arm 5, together with the bearing pin 9 formed integrally therewith, is preferably made of cast metal, light metal casting, such as, for example, die-cast aluminum, being favored. The thread-forming nut 14, however, preferably made of tool steel, whereby a material pairing with a soft and a hard partner is realized, which allows a thread furrows in the bearing pin 9.

Of course, any other conceivable and suitable material pairings are also covered by the invention, such as a metal-plastic material pairing or others.

In Figs. 2 and 3, a radially enlarged flange portion 17 of the thread-rolling nut 14 is further shown, whereby a frontal pollution protection of the rolling bearing 8 is realized. By this measure, a conventionally used cap 12 (FIG. 1) is dispensable.

The thread-forming nut 14 screwed onto the bearing pin 9 during assembly of the roller 1 together with the rolling bearing 8 preferably scores a metric screw thread, so that, for example, in an emergency, such as in a loss of the thread-rolling nut 14 to be avoided per se, also conventional nuts Metric thread for attachment are used.

According to a further, not shown embodiment of the connection assembly according to the invention, it is provided that the threaded bore of the thread-forming nut 14 is cylindrical in cross-section and accordingly a conventional fastening nut with, for example metric thread and radius profiling may correspond, but now the bearing pin 9 in Cross section has the shape of a polygon with three or more outwardly rounded form webs, whereby the conditions are given that said mother can act as a thread-forming nut 14.

With a knowledge of the invention, it will certainly be easy for the person skilled in the art to understand that the thread-rolling nut 14 is not only suitable exclusively for the above application, but also manifold applications recorded, which in turn allow a positive and non-positive and releasable connection between the thread-forming nut 14 and a cylindrical bearing pin 9 or any other suitable pin by cutting grooves without a thread in the bearing pin 9 or pin by means of said nut 14.

reference numeral

1 roller

2 clamping device

3 basic element

4 receiving element

5 swivel arm

6 plain bearings

7 torsion spring

8 rolling bearings

8a inner ring

8b outer ring

8c rolling elements

9 journals

10 tapped hole

11 fixing screw

12 cap

13 screwing section

14 thread-rolling nut

15 radial bar (swivel arm 5)

16 support section (bearing pin 9)

17 flange section (thread-forming nut 14)

18 support section (thread-rolling nut 14)

Claims

claims

1. Connecting arrangement between a roller (1) and a clamping device (2) for a belt, wherein the roller (1) of at least one, an inner and an outer ring (8a, 8b) and arranged therebetween rolling bodies (8c) having Rolling bearing (8) is carried, characterized in that the inner ring (1) of the at least one rolling bearing (8) radially at least indirectly on a cantilevered bearing pin (9) of a pivot arm (5) of the clamping device (2) is supported and axially by means of a from the free end of the bearing pin (9) forth on a screwed portion (13) thereof the same screwed and frontally engaging thread-forming nut (14) against a radial web (15) of the pivot arm (5) is stretched.

2. Connecting arrangement according to claim 1, characterized in that the threaded bore of the thread-rolling nut (14) in cross-section has the shape of a polygon with three or more inwardly rounded form webs, the thread with a largely cylindrical bearing pin (9) can be brought into engagement ,

3. Connecting arrangement according to claim 1, characterized in that the threaded bore of the thread-forming nut (14) is cylindrical in cross-section and with a bearing pin (9) can be brought into engagement, whose cross-section is the shape of a polygon with three or more to the outside having rounded shape webs.

4. Connecting arrangement according to claim 2 or 3, characterized in that the threaded bore of the thread-rolling nut (14) or the bearing pin (9) in cross-section preferably have a trilobular shape, wherein the thread of the thread-rolling nut (14) is provided with a radius profiling ,

5. Connecting arrangement according to one of claims 1 to 4, characterized in that the inner ring (8a) of the rolling bearing (8) radially on a support portion (16) of the bearing pin (9) is supported, which in the axial direction directly to the radial web ( 15) of the pivot arm (5) connects and selected to be larger in diameter than the screw connection portion (13) of the bearing pin (9).

6. Connecting arrangement according to one of claims 1 to 5, characterized in that the thread-forming nut (14) in addition to a radial flange portion (17) has an axially oriented support portion

(18), on which the inner ring (8a) of the rolling bearing (8) is radially supported.

7. Connecting arrangement according to one of claims 5 and 6, characterized in that in the bore of the inner ring (8 a) of the

Rolling bearing (8) reaching into the supporting portion (16) of the bearing journal (9) and / or the support portion (18) of the thread-forming nut (14) are tapered conically.

8. Connecting arrangement according to one of claims 1 to 7, characterized in that the pivot arm (5) together with an integrally formed with the same bearing pin (9) consists of cast metal.

9. Connecting arrangement according to claim 8, characterized in that the pivot arm (5) together with the bearing pin (9) made of lightweight cast metal, such as die-cast aluminum.

10. Connecting arrangement according to one of claims 1 to 9, characterized in that the thread-forming nut (14) consists of tool steel.

11. Connecting arrangement according to one of claims 1 to 10, characterized in that the radial flange portion (17) of the thread-forming nut (14) is formed radially enlarged such that an end-side contamination protection of the rolling bearing (8) is realized.

12. Thread-forming nut (14) for positive and non-positive and releasable connection with a cylindrical bearing journal (9) or pins, wherein the threaded bore in cross section has the shape of a polygon with three or more inwardly rounded molding webs.

13. Thread-forming nut according to claim 12, characterized in that the threaded bore of the thread-forming nut (14) has a lobular shape in cross-section a Tri, wherein the thread thereof is provided with a radius profiling.