WO2006042639A1

WO2006042639A1 - Thin annular bearing

Info

Publication number: WO2006042639A1
Application number: PCT/EP2005/010710
Authority: WO
Inventors: Alexander Zernickel; Herbert Erhardt; Wolfgang DÖPPLING
Original assignee: Schaeffler Kg
Priority date: 2004-10-19
Filing date: 2005-10-05
Publication date: 2006-04-27
Also published as: DE102004050728A1

Abstract

The invention relates to a thin annular bearing that has a very small cross section compared to the bearing diameter and comprises two bearing rings between which rolling elements roll on associated raceways. The invention is characterized in that the bearing rings (12, 13, 17, 18, 23, 24) are produced using a non-cutting shaping process while one of the bearing rings (12, 13, 17, 18, 23, 24) is provided with a raceway (12.1, 13.1, 17.1, 18.1, 23.1, 24.1) that encompasses an elastically resilient raceway arch (13.2, 21.1) deviating from the annular shape thereof in at least one peripheral section such that at least one of the rolling elements (15, 20, 26) is radially prestressed between the raceway arch and the raceway (12.1, 17.1, 23.1) located across therefrom. The inventive bearing has the advantage of being very easy to produce while having no play.

Description

Thin section bearings

Field of application of the invention

The invention relates to a thin-section bearing with a very small cross section with respect to the Lager¬ diameter with two bearing rings, between which rolling on corresponding raceways rolling elements. Moreover, the invention relates to a method for producing a thin-film bearing.

Background of the invention

Such thin-ring bearings, in which, in contrast to standard Wälzlagerrei¬ hen the cross section with the bearing diameter does not or only slightly increases, there are as four-point bearings, deep groove ball bearings and angular contact ball bearings in a bearing diameter range between 25 and 1000 mm. Main fields of application are handling devices, industrial robots, textile and printing presses, medical, optical and optronic devices, aerospace. The advantages of such generic Dünnringlagern are a low mass, low torque and the ability to create spatial and weight-saving construction, which have a high rigidity and running accuracy. Such Dünnringlager are described, for example, on page 10 of Fach¬ book "The Wälzlagerpraxis", Manual for the calculation and design of bearings, united specialist publisher GmbH, Mainz 1995.

The disadvantage of the previously known thin-ring bearings is that they are very expensive due to their machining production. The very thin-walled rings have to be hardened consuming because of strong deformation, ie, hardened tied and then ground in several grinding passes. It is also disadvantageous that thin-section bearings according to the prior art require highly accurate bearing seats which can likewise be produced only by complicated grinding operations. 4546-10-EN 2

Summary of the invention

Based on the disadvantages of the prior art, the invention is therefore based on the object to provide a new type of Dünnringwälz¬ camps, which can be manufactured in particular cost and have a low backlash.

According to the invention, this object is achieved according to the characterizing part of claim 1 in conjunction with the preamble in that the bearing rings are produced by a non-cutting shaping process and in that one of the bearing rings has a raceway which in at least one peripheral portion has a circular shape deviating elastically yielding track curvature such that at least one of the rolling elements between the raceway curvature and this opposite track is radially biased.

An advantage of the thin-section bearing according to the invention is its simple manufacture by chipless technology. This term is to be interpreted broadly in the sense of the invention and is intended to include all the non-cutting process known to the person skilled in the art. The thin-ring bearings produced in this way do not require subsequent machining of the bearing rings, since the bearing tolerances are compensated by the shape of the outer or inner ring. Another advantage is the possible adjustment of the backlash, which has a positive effect on the formation of noise in particular. A further advantage lies in the fact that the bearing rings produced without cutting have a smaller radial space compared with the bearing rings produced by machining, so that the saving of installation space is possible once again.

Further advantageous embodiments of the invention are described in the subclaims.

Thus, it is provided according to claim 2, that the raceway of the bearing outer ring has a different from their circular shape career curvature. These variables 4546-10-EN 3

Ante is the main variant, since in almost all cases it is important to keep the part to be stored free of play.

According to a further feature of the invention according to claim 3, the Dünn¬ ring bearing should be as a deep groove ball bearing, an angular contact ball bearings or as a Vierpunkt¬ ball bearings. The respective bearing variant depends on the predetermined installation case, which determines the special requirements for the bearing type.

According to an additional variant according to claim 4 it is provided that the deviating from the circular shape elastically compliant raceway curvature is formed by an inserted in a groove of a bearing ring elastic spring element, spielsweise, by a resilient ring. In this way, virtually a wire rolling bearing has arisen, which enables simple manufacture of the bearing rings. These then do not need to be subjected to expensive curing processes, for example. The resilient rings, which are placed in the appropriate recess of the bearing rings, consist of high quality spring steel wires and are blown up. The distance between the wire ends ensures that the wire rings fit well and can also expand freely in the event of temperature fluctuations.

In the claims 5 and 6 bearing rings are described, which are provided with a radially inwardly or radially outwardly directed flange, wherein the flange is provided with through-holes fastening. In this way an adaptation to the surrounding construction and a simple fixation is ensured.

In claim 7, a further variant of the thin-film bearing is described. Da¬ after a blasted bearing outer ring is received by a sleeve which is provided at one end with a radially outwardly directed flange. The bearing outer ring provided with a radial slot can thereby be inserted into the sleeve in a simple manner. The flange including Befestigungs¬ hole in turn provides a connection with a predetermined An¬ schlusskonstruktion, wherein according to claim 8, the flange by two in axial 4546-10-EN 4

Direction offset areas may be formed, which are designed with Befesti¬ supply holes.

According to an additional further feature according to claim 9, the Lager¬ outer ring should be formed from a profiled tape that is cut to length and rounded in accordance with the desired later bearing diameter, be¬ before it is verbun¬ at its abutting ends by a weld. Through this technology, the bearing ring is produced in a particularly simple manner.

It has proved to be advantageous according to claim 10, when the weld is positioned in a load-free zone of the bearing outer ring. This ensures that the weld is not overrun by the rolling elements of the bearing.

Finally, according to claim 11, the thin-section bearing should be used to support a fixed inside of a steering wheel of a motor vehicle fixed airbags, the steering wheel with a steering shaft is rotatably ver¬ connected, which is received via two spaced rolling bearings in a Lenk¬ tube ,

The determination of the airbag within the steering wheel is of particular importance for the safety of the driver, since in the event of a crash the airbag should always open in the same direction, independently of the respective steering wheel steering, which offers the driver the greatest possible protection , Thin-section bearings are particularly suitable because, on the one hand, they only have to withstand low loads in this case and, on the other hand, they must cover a large radial installation space.

In a particularly cost-effective manner, the bearing according to the invention can be made of a thin-walled strip, which is provided on one side with a substantially spherical track by a non-cutting shaping process, then this strip is cut to length, rounded and attached to its own surface 4546-10-EN 5

abutting ends is welded before the thus formed Lager¬ ring is subjected to a further forming operation for generating the deviating from the circular shape.

The invention will be described in more detail in the following exemplary embodiments.

Brief description of the drawings

Show it:

1 shows a longitudinal section through a thin-ring bearing,

FIG. 2 shows a side view of the thin-section bearing according to FIG. 1,

FIG. 2 a shows a schematic, greatly exaggerated representation of a cross section through an outer ring with a raceway deviating from the circular shape,

Figures 3, 4 is a longitudinal section through different embodiments and

Figure 5 shows a longitudinal section through a steering column including steering wheel and airbag.

Detailed description of the drawings

To explain the deviating from the circular shape elastically compliant career curvature, reference is first made to Figure 2a, in which such a La ger is shown schematically in greatly enlarged distortion. There, a bearing inner ring designated by 1 is shown, which has a shaft denoting 2. 4546-10-EN 6

takes, with the bearing inner ring 1 has a circular shape. For Lageran¬ order further includes the bearing outer ring 3, which has a deviating from the circular shape shape. In the present case, the bearing outer ring 3 at three offset by 120 ° to each other peripheral portions track curvatures 4. The track curvatures 4 are elastically yielding in the radial direction, so that on the one hand the shaft 2 is firmly biased in three circumferential regions, since the guided in the cage 5 rolling elements 6 bear against both the inner race 7 and the outer race 8, while on the other hand a Eigen¬ movement of the shaft 2 is possible by overcoming the resulting from the career curvatures 4 elasticity. The person skilled in the art designates this shape of the bearing outer ring 3 as a polygon, wherein the equatorial circle of the inner raceway 7 and the enveloping circle of the receiving bore 9 corresponds. The radial distance between enveloping circle and raceway curvature 4 is designated as radial incidence Δ r.

If such a bearing outer ring 3 made of a band, it has proved to be advantageous if the weld 10 is placed in the load-free area, i. in the area in which the rolling elements 6 do not come into contact with the outer running track 8.

The illustrated in Figures 1 and 2 thin-section bearing 11 consists of the bearing inner ring 12 and the bearing outer ring 13, both of which are made without cutting. Between the two 14 guided bearing balls 15 roll in the cage on zugehö¬ rigen raceways 12.1, 13.1 from. The bearing inner ring 12 is provided on the left side with the radially inwardly directed flange 12.2, which is equipped with through-holes fastening 12.3. As shown in FIG. 2, the outer bearing ring 13 is polygonal-shaped, i. he has at three different circumferential positions on the track curvatures 13.2, so that in this area the bearing balls 15 abut both raceways 12.1, 13.1, i. that Dünn¬ ring bearing 11 is biased accordingly.

The thin-ring bearing 16 shown in FIG. 3 consists of the bearing inner ring 17 and the bearing outer ring 18, between which bearing balls 20 guided in the cage 19 on associated raceways 17.1, 18.1 roll. For attachment 4546-10-EN 7

a connecting construction of the bearing inner ring 17 is provided with the radially in¬ NEN directed flange 17.2, which is equipped with evenly arranged around the circumference mounting holes 17.3. In this exemplary embodiment, the elastically yielding raceway convexity 21. 1 is formed by an elastic element 21 in the form of a resilient ring which is inserted into a groove in the bearing outer ring 18.

The thin-section bearing 22 shown in FIG. 4 consists of the bearing inner ring 23 and the bearing outer ring 24, between which bearing balls 26 guided in the cage 25 on associated raceways 23.1, 24.1 roll. The bearing inner ring 23 is equipped with the radially inwardly directed flange 23.2. The Lager¬ outer ring 24 in turn at three spaced peripheral positions radially inwardly directed career curvatures, so that in this area the bearing balls 26 abut both on the inner race 23.1 and on the outer race 24.1. The provided with a slot Lageraußen¬ ring 24 is received by the sleeve 27, the radially outwardly directed flange 27.1 consists of two mutually offset in the axial direction of areas, which are provided with mounting holes 27.2.

Finally, FIG. 5 schematically shows a steering arrangement in which a steering wheel 28 is non-rotatably connected to a steering spindle 29, which has two spaced-apart rolling bearings 30, 31 in a steering tube

32 is included. The steering wheel 28 is rotatable via another rolling bearing

33 supported and receives in its interior the airbag 34 which is mounted on a thin-ring bearing 35 of the type described above. If the steering wheel 28 is now turned to the right or to the left, the bearing inner ring 35.1 connected thereto rotates, while the bearing outer ring 35.2 and the airbag 34 connected to it remain in its position, ie, does not move. This ensures that despite different position of the steering wheel 28, the airbag 34 always remains in the same position, which causes the greatest possible protection for the driver during its deployment. 4546-10- EN 8

reference numeral

1 bearing inner ring

2 wave

3 bearing outer ring

4 career curvature

5 cage

6 rolling elements

7 inner raceway

8 outer raceway

9 receiving hole

10 weld

11 thin ring bearings

12 bearing inner ring

12.1 career

12.2 Flange

12.3 Mounting hole

13 bearing outer ring

13.1 career

13.2 Raceway curvature

14 cage

15 bearing ball

16 thin ring bearings

17 bearing inner ring

17.1 career

17.2 Flange

17.3 Mounting hole

18 bearing outer ring

18.1 career

19 cage

20 bearing ball

21 elastic element

21.1 Track curvature 4546-10-EN

22 thin ring bearings

23 bearing inner ring

23.1 career

23.2 Flange

24 bearing outer ring

24.1 career

25 cage

26 bearing ball

27 sleeve

27.1 Flange

27.2 Mounting hole

28 steering wheel

29 steering spindle

30 rolling bearings

31 rolling bearings

32 steering tube

33 rolling bearings

34 airbag

35 thin ring bearings

35.1 bearing inner ring

35.2 bearing outer ring

Claims

4546-10-EN 10Patentansprüche

1. Thin-section bearing (11, 16, 22) with a very small cross-section in relation to the Lagerdurchmes¬ with two bearing rings (12, 13, 17, 18, 23, 24), between which on associated raceways (12.1, 13.1, 17.1, 18.1, 23.1, 24.1) rolling elements (15, 20, 26), characterized gekenn¬ characterized in that the bearing rings (12, 13, 17, 18, 23, 24) are made by a span¬ loose molding process and that one of Lagerrin ¬ GE (12, 13, 17, 18, 23, 24) has a track (12.1, 13.1, 17.1, 18.1, 23.1, 24.1), which in at least one peripheral portion deviates from its circular shape elastically yielding track curvature (13.2, 21.1) has such that at least one of the rolling elements (15,20,26) between the raceway curvature (13.2, 21.2) and this gegenüberlie¬ ing career (12.1, 17.1, 23.1) is radially biased.

2. thin-ring bearing (11, 16, 22) according to claim 1, characterized in that the raceway (13.1, 18.1, 24.1) of the bearing outer ring (13, 18, 24) has a different from its circular shape career curvature (13.2, 21.1).

3. thin-ring bearing (11, 16, 22) according to claim 1, characterized in that it is designed as a deep groove ball bearing, an angular contact ball bearing or as a four-point ball bearing.

4. Dünnringlager (22) according to claim 1, characterized in that the deviating from the circular shape elastically compliant Laufbahnwöl¬ advertising (21.1) by a in a groove of a bearing ring (18) inserted e- lastisches element (21), for example by a resilient Ring, ge forms is. 4546-10-EN 1 1

5. Dünnringlager (11, 16, 22) according to claim 1, characterized in that at least one of the bearing rings (12, 17, 23) with a radially inwardly or outwardly directed flange (12.2, 17.2, 23.2) is provided.

6. Dünnringlager (11, 16) according to claim 5, characterized in that the flange (12.2, 17.2) with continuous Befestigungsbohrun¬ gene (12.3, 17.3) is provided.

7. Dünnringlager (22) according to claim 2, characterized in that the bearing outer ring (24) blown up and from a sleeve (27) auf¬ taken, which is provided at one end with a radially outwardly directed flange (27.1).

8. thin-ring bearing (22) according to claim 7, characterized in that the flange (27.1) is formed by two mutually offset in the axial direction of areas, which are provided with mounting holes (27.2).

9. Dünnringlager (11, 16, 22) according to claim 2, characterized in that the bearing outer ring (13, 18, 24) of a profiled band gebil¬ det, which is cut to length according to the desired diameter and bent around before it on his abutting ends is connected by a weld.

10. Dünnringalger (11, 16, 22) according to claim 9, characterized in that the weld in a load-free zone of the bearing outer ring (13, 18, 22) is positioned.

11. Thin-section bearing according to claim 1, characterized in that it is used for mounting a within a steering wheel (28) of a motor vehicle arranged fixed airbags (34), wherein the steering wheel (28) with a steering shaft (29) is rotatably connected via 4546-10-EN 12

two spaced rolling bearings (30, 31) is received in a steering tube (32).

12. A method for producing the bearing outer ring (13, 18, 24) according to claim 2, characterized in that a thin-walled strip is provided by a non-cutting shaping process on one side with a We¬ sentlichen spherical track, this band anschlie¬ ßend cut, rounded and is welded at its abutting ends, before the thus formed bearing ring (13, 18, 24) is subjected to a further forming operation for producing the deviating from the circular shape.