DE19855538A1 - Tolerance ring for use in push-pull shaft arrangement minimizes mechanical play and allows for pre-setting of push-pull forces - Google Patents

Abstract

A push-pull shaft (2) is separated from a surrounding bush (3) by a spacer (1). The spacer is designed to compensate for dimensional inaccuracy. The push-pull shaft and the bush may slide back and forth with respect to each other.

Description

Field of application of the invention

The invention relates to a tolerance ring, which is arranged between a shaft and at least one annular element, wherein

• - At least one sliding section is formed on the shaft and on the outer circumference of the sliding portion in the circumferential direction other longitudinal ribs and longitudinal grooves are alternately formed,
• - The annular element associated with the sliding section of the shaft is
• - The shaft and the annular element in the longitudinal direction of the shaft are slidably arranged,
• - The shaft and the annular element in the circumferential direction by the Effect of the tolerance ring are arranged rotatably to each other and  
• - The shaft and the annular element are supported elastically to one another are,

and being the tolerance ring

• - A radial distance between the sliding section and the balances out annular element,
• - Has a seat for the annular element on which the annular Element rotatable in the circumferential direction and ver in the longitudinal direction non-slip, is included and
• - With elements formed on its inner surface for twisting securing in a meshing engagement with the longitudinal ribs and Longitudinal grooves.

Background of the Invention

Tolerance rings are used between a shaft and an annular element arranged on the shaft in order to:

• - distances, d. H. Differences in diameter between the shaft and the to compensate for the annular element,
• - Manufacturing-related dimensional deviations in the seat of the ring-shaped ele to compensate mentes on the wave,
• - The forces that occur when the annular element is pressed onto the Wave to diminish,
• - Functional forces, e.g. B. displacement forces between the shaft and the annular element in the desired tolerance ranges hold,  
• - dampen shocks and vibrations,
• - Functionally required forces or moments between the shaft and the to transmit annular element as well
• - Location and shape deviations of the surrounding construction, such as. B. Deviations from the roundness, tilting and center offset equalize.

The above requirements arise depending on the con structural features of each individual installation site. Is accordingly also the constructive design of the tolerance rings different. Tolerance rings are z. B. for the bearing seat of rolling bearings in housings or on shafts used or between telescopically displaceable and with each other arranged on connected shafts.

An application example for tolerance rings, used for bearing seats and also telescopically displaceable shafts, forms a steering column Motor vehicle. Modern motor vehicles with height or longitudinally adjustable steering columns. With such steering columns Position of the steering wheel in the vehicle interior of the individual size and Adjusted posture of the operator.

The embodiments of adjustable steering columns are different. At almost all concepts, however, have steering shafts that are variable in length used. For this purpose, two shafts are telescopically slidable arranges. As the steering shaft the steering torque from the steering wheel to the steering gear transmits, the steering shafts must also be non-rotatably coupled his. It is not uncommon for these waves to be one at the shifting section inner shaft formed tooth profile, which in an assigned tooth profile engages an outer shaft in a form-fitting manner, coupled to one another in a torsion-proof manner and arranged longitudinally displaceable to each other. The overall arrangement of the  Steering shaft with steering wheel is usually with steering play without play like rotatably mounted in the housing of the steering column. The steering bearings are depending on the design concept of the steering column as a fixed or floating bearing educated. In the steering column, there are increasing impulses and associated ones Sensors, e.g. B. sensor technology for detecting the steering angle, rotatable arranged to each other.

The position of the steering wheel is either manually controlled by the physical strength of the Operator or adjusted via electric motors. Adjustment possible with both in the sliding seat of the telescopically movable to each other Ren shafts and the forces occurring in the sliding seat of the floating bearing be too high. There is play in the sliding seat and the bearing of the steering shaft not desirable as it leads to noise in the vehicle interior and adversely affects the accuracy of the information from the sensor technology. Backlash in the steering shaft also affects the quality of the steering negative. In the sliding seat of the inner to the outer shaft is therefore common a tolerance ring is used as well as a tolerance ring between Len kungslager and housing or arranged between the steering bearing and shaft is.

In the sliding seat of the steering shafts, the sliding section is at one inner shaft formed on which the tolerance ring slidably and ver is rotatably arranged. The ring-shaped element forms the outer shaft, too which the tolerance ring transmits torques in the circumferential direction and in Longitudinally fixed is fixed. The tolerance ring is in a bearing put on the steering shaft, so forms a bearing ring of the bearing annular element and the tolerance ring between the connecting element Shaft and bearing ring. Depending on the execution of the storage, d. H. as a festival or Floating bearing, the tolerance ring can be moved or shifted in the longitudinal direction firmly arranged.

An example of a tolerance ring between a steering bearing and a steering shaft is arranged, is in the specialist book "Chassis technology: steering"  by Jörnsen Reimpell, page 144, Vogel-Buchverlag, 1984. On Ribbed tolerance ring is between one in the cross-sectional profile flattened shaft and an inner ring of a bearing arranged. The Tole ranzring is prevented from twisting in the inner ring by a groove. The functi one of such a tolerance ring requires that he play in the Inner ring is arranged.

The seat diameter of the tolerance ring and the inner ring are usually designed so that between the outer diameter of the tolerance ring and the inner diameter of the inner ring is covered. In order to is prevented that production-related and within a manufacturing lot fluctuations in the Diameter, to a gap between the outer diameter of the tolerance ring and the inner diameter of the inner ring, which is greater than zero is. As a result of this covering, the wall is usually thin-walled and out Plastic tolerance ring constricted. Depending on the waiter the inner diameter of the tolerance ring is reduced about the amount of coverage. This constriction also changes the gap between the tolerance ring and the shaft immediately. In the event of a tight fit of the bearing ring on the shaft, the front increases tension because the gap dimension is designed to be smaller than zero from the outset. This effect can be advantageous and desirable for the tight fit.

However, the effect is disadvantageous if a sliding seat is required. The one lacing must be in the width of the entire tolerance band of wave, tole ranzring and inner ring from the outset as play in the seat between the tolerance ring and wave are taken into account. A completely play-free seat can do that after not be achieved. Such tolerance rings are therefore mostly made made of elastic material or have the game bridging elastic Elements that, however, in their elastic bias directly from the dimensional changes mentioned are affected. Desired displacement forces can can only be defined and required within very large tolerance ranges  often costly coordination and sorting of the individual parts at one Mass production.

The adjustment of the displacement forces is particularly difficult if Tolerance rings are designed for sliding seats, in which in the form fit backlash can occur between the shaft and the annular element. In addition to a large radial gap dimension, there is also a large backlash here to avoid. The backlash forms, seen in the circumferential direction, between the interlocking elements of the shaft and the Tolerance ring, e.g. B. between the flanks of an external toothing of the shaft and the associated flanks of an internal toothing of the tolerance ring. Such a tolerance ring, a tolerance ring of the generic type, is in Utility model DE 19 70 789 described. This tolerance ring is in shape a synthetic resin lining between two in the longitudinal direction to each other baren profiles arranged. The chuck is twist and shift resistant in formed an outer profile and sits on an inner profile. The inner contour of the lining is adapted to the outer contour of the inner profile. The inner profile can be in any cross-section that prevents rotation of the chuck shape, so also be designed in the form of a tooth profile. For that shooting Ownership can make the game small by costly tuning and sorting held but not avoided.

Summary of the invention

The object of the invention is therefore to provide a tolerance ring which between a shaft and an annular element produces a rotationally fixed and longitudinally displaceable connection,

• - The game is designed free of play
• - where the displacement force of the shaft and the annular element adjustable to each other in the desired size and of fluctuations  the dimensions of the elements involved are essentially inconsistent is flowing
• - When using it, especially in mass production, low Material and manufacturing costs are incurred.

This object is there according to the characterizing part of claim 1 solved by ver on the circumference of the inner surface of the tolerance ring shares at least two elastic ribs that are arranged in the longitudinal direction extend in the direction of the shaft, point radially inwards and each in a resiliently preloaded longitudinal groove. The two ribs are preferred arranged on the inner circumference of the tolerance ring opposite. At more than two ribs, these are preferably with a uniform pitch each other on the inner circumference of the tolerance ring. The tolerance ring is based on the displacement section of the shaft and to the longitudinal central axis the shaft centers over the ribs in the grooves. A movement game between Tolerance ring and shaft is avoided because the ribs against the tub tion of the grooves are resiliently biased.

Between the outer diameter of the sliding seat of the shaft and the The inner diameter of the inner shell of the tolerance ring is a gap forms, the dimensional changes of the shaft, the tolerance ring and the inner ring be within the entire tolerance band during mass production taken into account and which is always greater than zero. Constrictions on the inside knife of the tolerance ring, the z. B. by an interference fit of the tolerance ring arise in the ring-shaped element, have little influence on the displacements force of the annular element to the shaft.

The displacement force is essentially only be by the frictional force true, which is between the contact zones of the sliding section and of the tolerance ring. This frictional force depends on the preload the ribs to the sliding section and the friction pairing of the surfaces of the sliding section and the tolerance ring.  

The pretensioning force of the ribs can be determined by various design measures men can be influenced. Representing this are the number of ribs, the Material of the ribs, their length and their thickness called. The friction pairing can e.g. B. by differently paired surface roughness, materials or be influenced by the choice of lubricants.

In a preferred embodiment of the tolerance ring according to the invention on the flanks of the elastic ribs, each to the walls of the grooves of the sliding section, elastic areas are formed. This elastic areas can e.g. B. in the form of pimples emerging from the surface the flanks of the rib protrude. The knobs are either which is arranged so that there is at least one knob on each is supported on opposite walls of the groove, or the knobs are arranged so that the rib is supported radially on the rib base. A combination of both arrangements of the knobs is also conceivable.

If the knobs rest on the mutually facing walls of the groove, these nubs are elastically compressed when the rib engages in the groove and biased against each other. So that the rib in the groove is resilient ver tense. If the elastic areas are formed by knobs, which are in support in the radial direction in the base of the ribs, the ribs under the ela static preload of the knobs radially outwards against the tolerance ring biased. Because at least three of these ribs are on the circumference of the sliding face intervene, the tolerance ring is centered in this way in relation to the shaft. The aforementioned forms of training the ribs are particularly for the Intervention in grooves suitable, their opposite walls, in the transverse seen cut, are aligned parallel to each other.

It is also a preferred embodiment of the tolerance ring according to Invention described that ge especially for a sliding seat with grooves is suitable in which the walls are inclined. In cross section be the surface lines of the opposing walls run starting from the bottom of the ribs. Each of the elastic ribs  This tolerance ring is formed by at least two tongues. This guild are like the above-mentioned knobs between each other Opposite walls of the groove are arranged and are separated trained contact zones of their flanks on the wall. It is conceivable seen the tongues in the longitudinal direction of the shaft, very long or very short to form or to arrange several tongues in a row. To this Way z. B. the size of the displacement force of the shaft. If the rib engages in the groove, the tongues become elastic against each other preloaded and thus brace the ribs in the groove. Since the groove is in their cross-section tapers towards the bottom of the groove, the rib is elasticized prestress over the sloping walls outwards against the tole ranzring biased. The tolerance ring is centered by three in this way ribs formed and arranged on the circumference.

One or more contact zones are formed on each of the tongues, with which the tongue has contact with the wall of the groove. Every single tongue has in other words one or more specially designed areas with which you can access the Wall is applied. Wear can occur through the formation of the contact zones behavior of the ribs in the groove can be influenced. Individuals are conceivable point or area-shaped contact zones, or in preferred Embodiment linear contact zones. On a tongue can NEN one or more arranged side by side or one behind the other linear contact zones are provided. It is also conceivable arrange lubricant pockets between the individual contact zones.

Another embodiment of the invention provides the elastic ribs at the same time as an anti-rotation device to prevent the tolerance ring from rotating in To use circumferential direction of the shaft. Depending on the size of the file to be transferred For this purpose, at least three or more are arranged on the circumference To provide elastic ribs that mesh with the sliding seat of the shaft.

Preferably, a tolerance ring according to the invention is a tolerance ring  stalten that between a bearing inner ring, for. B. for a steering bearing, and a shaft is arranged. The elastic ribs of this tolerance ring are executed according to the above features of the invention. For the inside ring sees the invention a separate elastic seat on the tolerance ring in front. The seat is distributed by a circumferential or by the circumference elastic ramps formed. When the bearing ring is pushed onto this seat , the ramps deflect and tighten the bearing ring to the tolerance ring elastic. The ring is in the axial direction when viewed in both directions secured by one or more axial stops. On the one hand the axial stops on the ramps are formed. On the other hand by either a circumferential or interrupted one Board or secured by multiple stops. The bearing ring is on press on the ramps over the board or pushed the stops so that these are designed to be resilient radially inward, for example as a snap nose have to be. If the bearing ring sits on the ramps, the stops spring again back to their starting position.

The advantage of such a bearing seat is that the tolerances of the Bearing ring absorbed by the elasticity of the ramps and therefore not in Form of constrictions are transferred to the sliding seat. In addition this system has a dampening effect. So z. B. in a steering column, Schwin from inside the vehicle, over the steering tube, from the len Kungslager be transferred to the steering shaft and thus to the steering wheel, dampened by such elastic ramps.

Finally, it is provided that the tolerance ring from a polymeric plant fabric is formed. Such a tolerance ring made of plastic is a easy to manufacture and saves material and has good damping and sliding properties properties. Polyoxymethylene should preferably be used as the material.

Brief description of the drawings

The invention is based on two exemplary embodiments  purifies. Show it:

Fig. 1 shows a portion of a sliding telescopically image th wave with one embodiment of a tolerance ring according to the invention in section;

Fig. 2 is a sectional view through the sliding portion of the shaft of FIG. 1 along the line II,

FIG. 2a, the detail Z of Fig. 2, wherein the engagement of an elasti rule rib in a groove increases,

FIG. 2b shows the detail Z of Fig. 2 with an alternative embodiment of the elastic elastic rib of FIG. 2, in the form of tongues,

Fig. 2c, the detail Z of Fig. 2 illustrating a to Fig. 2b alternative embodiment of the resilient tongues,

With the representation of a further to Fig. 2b alternative embodiment of the elastic Zun gen Fig. 2d the detail Z of Fig. 2,

Fig. 3, a steering bearing, with the seating of its inner ring on egg nem embodiment of a tolerance ring according to he invention in section,

Fig. 4 is a 90 ° turned view of the headset of FIG. 3,

Fig. 5 shows the tolerance ring of the steering bearing according to Fig. 3, Darge without bearings.

Detailed description of the drawing

In Fig. 1, an embodiment of a tolerance ring 1 according to the invention between the displacement section 2 of a not further drawn shaft and a portion of a hollow shaft 3 is shown in section. The Tole ring 1 is pressed into the section of the hollow shaft 3 . The hollow shaft 3 with the tolerance ring 1 and the sliding section 2 are arranged to be displaceable relative to one another in the longitudinal direction. As can be seen from Fig. 2, the sliding section Ver 2 is provided on its outer circumference with an external toothing formed by longitudinal ribs 4 and grooves 5 . On the inner circumference of the ring ring Tole 1 longitudinal ribs 6 and four elastic ribs 7 are formed, which engage in grooves 5 of the external teeth. Each elastic rib 7 is supported on its flanks 7 a nubs 7 b on the wall of the groove 5 , while the other areas of the external toothing to the longitudinal ribs 6 and longitudinal grooves 8 of the tolerance ring 1 are arranged with a game S. The tolerance ring 1 centers the hollow shaft 3 via the elastic ribs 7 in the center of the sliding section 2 . The elastic rib 7 is resiliently biased in the longitudinal groove 5 . Only when the displacement section 2 of the shaft and the hollow shaft 3 against each other, for. B. are loaded by radial load or torques and the spring preload of the elastic ribs is overcome, the displacement section 2 and the hollow shaft 3 ge against each other until the game S is overcome and the tolerance ring 1 with its longitudinal ribs 6 on the external teeth of the displacement section supports.

In FIGS. 2a to 2d particular embodiments of elastic ribs are illustrated in accordance with the invention. The elastic rib 7 , shown in Fig. 2a, is based on its flanks 7 a nubs 7 b on the wall of the longitudinal groove 5 from. In Fig. 2b, an elastic rib is shown, which is formed from two elastic tongues 9 . According to the representation in Fig. 2c, the elastic rib is formed by elastic tongues 10 , which start from a common base 10 c. On the flanks 9 a of the elastic tongues 9 and the flanks 10 a of the elastic tongues 10 , contact zones 9 b and 10 b are formed, via which the elastic tongues 9 and 10 have contact with the wall of the groove 5 . In the exemplary embodiment according to FIG. 2 d, each of the elastic tongues 11 starting from a common base 11 c forms two contact zones 11 b on its flank 11 a for the wall of the longitudinal groove 5 .

In Fig. 3, a tolerance ring 12 is shown, on the inner circumference elastic tongues 13 and longitudinal ribs 14 are formed. The entire length of each elastic tongue 13 is provided in its region of the contact zone 13 a for a linear contact with a not shown groove of a Verschiebeab section of a shaft. A bearing seat 15 for an inner ring 16 a of a steering bearing 16 is provided on the outer circumference of the tolerance ring 12 . Elastic ramps 17 form the bearing seat 15 . The bearing seat 15 is depicted in its details in Fig. 3 and Fig. 4. Fig. 4 is a 90 ° turned view shows the tolerance ring 12 and the steering bearing 16 of FIG. 3. FIG. 5 shows the tolerance ring 12 is illustrated as a single part without bearing 16. The elastic ramps 17 are distributed at equal intervals on the outer circumference of the tolerance ring 12 and the same at the same time resiliently a radial distance R between the outer diameter of the tolerance ring 12 and the inner ring 16 a from. The spring action is possible because the elastic ramps 17 are thin-walled and inclined at an acute angle α to an imaginary tangent that runs through the intersection of the generatrix of the elastic ramp 17 with the outer jacket of the tolerance ring 12 .

First stoppers 17 are provided a for securing the axial seat of the inner ring 16 of the headset 16 in a direction to the elastic ramps 17th In the other direction, the inner ring 16 a is secured via second axial stops 18 a. The second axial stops 18 a are formed on snap lugs 18 . When installing the steering bearing 16 , the inner ring 16 a is pushed in the axial direction over the snap lugs 18 which deflect radially inwards. When the inner ring 16 a is seated on the bearing 15 , the snap lugs 18 snap back into their starting position.

Reference list

1

Tolerance ring

2nd

Sliding section

3rd

Hollow shaft

4th

Longitudinal ribs

5

Longitudinal groove

6

Longitudinal rib

7

elastic rib

7

a flank

7

b pimples

8th

Longitudinal groove

9

elastic tongue

9

a flank

9

b contact zone

10th

elastic tongue

10th

a flank

10th

b contact zone

10th

c base

11

elastic tongue

11

a flank

11

b contact zone

11

c base

12th

Tolerance ring

13

elastic tongue

13

a contact zone

14

Longitudinal rib

15

Camp seat

16

Headset

16

a inner ring

17th

elastic ramp

17th

a first axial stop

18th

Snap nose

18th

a second axial stop

Claims (7)

1. tolerance ring ( 1 , 12 ) which is arranged between a shaft and at least one annular element ( 3 , 16 a), wherein

• at least one sliding section ( 2 ) is formed on the shaft and longitudinal ribs ( 4 ) and longitudinal grooves ( 5 ) are alternately formed on the outer circumference of the sliding section ( 2 ) in the circumferential direction,
• - The annular element ( 3 , 16 a) is assigned to the sliding section ( 2 ) of the shaft,
• - The shaft and the annular element ( 3 , 16 a) are arranged to be displaceable relative to one another in the longitudinal direction of the shaft,
• - The shaft and the annular element ( 3 , 16 a) by the effect of the tolerance ring ( 1 , 12 ) are arranged in the circumferential direction to each other and
• - The shaft and the annular element ( 3 , 16 a) to each other are ela stically supported

and the tolerance ring ( 1 , 12 )

• - compensates for a radial distance between the sliding section ( 2 ) and the annular element ( 3 , 16 a),
• a seat ( 15 ) for the ring-shaped element ( 3 , 16 a) on which the ring-shaped element ( 3 , 16 a) is received in the circumferential direction in a rotationally fixed manner and in the longitudinal direction in a manner fixed against displacement
• - With elements ( 6 , 8 ) formed on its inner lateral surface to prevent rotation, it meshes with the longitudinal ribs ( 4 ) and longitudinal grooves ( 5 ),
  characterized in that at least two elastic ribs ( 7 ) are arranged on the circumference of the inner circumferential surface of the tolerance ring and extend radially inwards in the longitudinal direction of the shaft and are each resiliently supported in a longitudinal groove ( 5 ).

2. Tolerance ring according to claim 1, characterized in that each elastic rib ( 7 ) on mutually facing and facing the wall of the longitudinal groove ( 5 ) flanks ( 7 a) has elastic regions ( 7 b) and with the elastic regions on the Walls of the longitudinal groove ( 5 ) are spring-supported. 3. Tolerance ring according to claim 1 characterized by the following features:

• - Each elastic rib is formed by at least two ge spread apart elastic tongues ( 9 , 10 , 11 )
• - The elastic tongues ( 9 , 10 , 11 ) each form at least one contact zone ( 9 b, 10 b, 11 b) with at least one flank ( 9 a, 10 a, 11 a) that faces the wall of the longitudinal groove. with the wall and
• - The elastic tongues ( 9 , 10 , 11 ) are resiliently biased against the wall of the longitudinal groove ( 5 ) over the contact zone ( 9 b, 10 b, 11 b).

4. Tolerance ring according to claim 1, characterized by the following features:

• - Each elastic rib is formed by at least two spread apart elastic tongues ( 9 , 10 , 11 ),
• - The elastic tongues ( 9 , 10 , 11 ) each form with at least one flank ( 9 a, 10 a, 11 a) facing the wall of the longitudinal groove ( 5 ), at least one linearly aligned longitudinal contact zone with the wall of the Longitudinal groove ( 5 ),
• - The elastic tongues ( 9 , 10 , 11 ) are resiliently biased over the contact zone against the wall of the longitudinal groove ( 5 ).

5. Tolerance ring according to claim 1, characterized in that the ela-elastic rib ( 7 , 9 , 10 , 11 ) forms the element for preventing rotation. 6. Tolerance ring according to claim 1, characterized by the following features:

• - The seat for the annular element is a bearing seat ( 15 ) for egg NEN bearing ring ( 16 a) of the shaft rotatably mounted in the circumferential bearing ( 16 ),
• - The bearing seat ( 15 ) is formed at least one elastic ramp ( 17 ), at least one axial first stop ( 17 a) and by we least a second axial stop ( 18 a),
• - The elastic ramp ( 17 ) is arranged on the outer circumference of the tolerance ring ( 12 ),
• - The elastic ramp ( 17 ) protrudes over the outer surface of the tolerance ring ( 12 ),
• - The elastic ramp ( 17 ) compensates for a radial distance between the tolerance ring's ( 12 ) and the bearing ring ( 16 a),
• - The elastic ramp ( 17 ) is radially resiliently biased against a ring ring ( 12 ) surrounding the inner circumferential surface of the bearing ring ( 16 a),
• - The axial first stop ( 17 a) is distributed on the outer circumference of the tolerance ring ( 12 ),
• - The axial first stop ( 17 a) is formed on at least one elastic ramp's ( 17 ),
• - The axial first stop ( 17 a) protrudes in the radial direction from the ramps,
• - The second axial stop ( 18 a) protrudes in the radial direction from the outer surface of the tolerance ring ( 12 ) and
• - The second axial stop ( 18 a) is arranged on the side of the bearing seat ( 15 ) opposite the first axial stops ( 17 a).

7. Tolerance ring according to claim 1, characterized in that the tolerance ring ( 1 , 12 ) is formed from a polymeric material.