DE102006053715A1 - Roller bearing e.g. radial bearing, for motor vehicle, has intermediate layer, designed and adapted to be arranged between one of bearing discs and bearing disc support, and made of plastic - Google Patents

Abstract

The bearing has bearing discs (9, 10) pivoted together by bearing bodies (3) e.g. needle and rollers. The bearing discs are provided with an intermediate layer (5), which is designed and adapted to be arranged between one of the discs and a bearing disc support, which corresponds to the bearing discs. The intermediate layer is made of plastic having a Poisson's ratio greater than 0.48 and is provided as a part of an intermediate part e.g. annular disc and radial sleeve, which is inserted between one of the discs and the support.

Description

The The invention relates to a rolling bearing according to the preamble of claim 1.

roller bearing are used in mechanical arrangements for the storage of shafts and axles diverse used. To adapt to the different fields of application is now a sprawling Type diversity known.

Next the actual, function-related structure of the bearings Depending on the application, the adaptation of the rolling bearings with respect to the Type of mounting in the mechanical arrangements or in the connection components special attention.

For example, in the published patent application DE 19525965 A1 proposed to provide raceway rings of rolling bearings at their peripheral surfaces with an adhesion-enhancing inorganic-chemical protective layer to improve the stability of the rolling bearings in the installed state. Through the protective layer is to be achieved that the necessary during press-fitting of the rolling bearing in a housing press-in forces only slightly increased, but the Auspresskräfte to remove the bearing from the housing are considerably increased. As protective layers, oxidation or burnishing layers are disclosed.

The publication DE 10 823 928 A1 On the other hand, it generally proposes to use a connecting element for the non-positive connection of components, which consists of a thin, flexible layer which carries particles of defined size on its surface. During assembly of the components, the connecting element is arranged between the components, wherein the particles press into the components and thus significantly increase the friction between the assembled components.

The patent specification pursues a different approach DE 198 36 678 C1 in which a wheel bearing unit for a driven wheel of a motor vehicle is disclosed. In this patent, it is proposed to coat the faces of prestressed radial bearings with lubricants to counteract the emergence of cracking noises. As a lubricant, for example, PTFE, MoS2 or the like are proposed.

Yet another way is the European patent EP 0 125 718 B1 which is probably the closest prior art. This document discloses a radial rolling bearing in which between the inner ring and a shaft to be mounted or between the outer ring and the bearing seat is arranged in each case an intermediate layer which is fixedly connected to one of the joining partners. The respective free surface of the intermediate layer is pretreated in a special way, so that it is almost completely smooth and dense, with the purpose to obtain a "close contact" with the free surface of the corresponding joining partner.This "close contact" must have such a high coefficient of friction so that no oscillating Relativgleitbewegungen can arise between the free surface of the intermediate layer and the free surface of the corresponding joining partner during operation of the bearing.

outgoing From this known prior art, the invention has the object underlying, more solutions for one advantageous mounting of rolling bearings to propose in bearing seats or on shafts or axles.

These Task is solved through a rolling bearing with the features of claim 1. Advantageous and / or preferred embodiments emerge from the subclaims, the following description and the accompanying figures.

The Rolling bearing according to the invention has a first and a second storage device and a plurality of rolling elements, wherein the first and the second bearing means by means of the rolling elements to each other rotatable are stored. Preferably, the storage facilities are as thrust washers or formed as a radial bearing rings. The rolling bearing is thus around a rolling bearing any design, in particular an axial roller bearing or a radial rolling bearing, wherein the rolling elements in particular are designed as rollers, balls, tons or needles. optional can additional Wälzkörperkäfige for captive receiving the rolling elements provided be. The first and the second storage device designates each the outside, for mounting the rolling bearing used storage facilities and are preferably made of a metallic Material. In particular, run or roll on the inside of the first and second bearing means, the rolling elements. In a possible execution is the rolling bearing as encapsulated axial roller bearing educated.

The roller bearing comprises at least one intermediate layer of plastic, which is formed and / or adapted to be between one of the storage facilities and a storage facility receptacle corresponding to this storage facility to be arranged. The bearing fixture receptacle is preferred designed as a bearing seat, in particular fixed seat. alternative The bearing fixture can be realized as a shaft or axis be.

outgoing from the problem of optimal mounting of a rolling bearing in a housing, was on a shaft or axle or other arrangement of the inventor found that walking, in particular micro-walking, the bearing device in the bearing device recording by differences in expansion the surfaces in contact Lagerein direction and storage facility recording is justified. These differences in expansion result from different deformations from storage facility and storage facility receiving through the the rolling bearing rolling rolling elements. It was recognized that when using an intermediate layer of plastic, the friction coefficient between the intermediate layer and the surrounding components only one subordinate role plays, if a sufficiently schoffe soft material chosen as intermediate layer becomes. However, the friction coefficient must be at least as high be that the interlayer does not slip.

Therefore, according to the invention according to a Alternative A suggested the intermediate layer of a plastic form, whose shear modulus is low and its transverse contraction number is high, so that the intermediate layer is as incompressible. With such an intermediate layer, the surface-elongation differences become between the storage facility and the storage facility receptacle elastically balanced. Due to the comparatively high transverse contraction number At the same time it is ensured that the bearing stiffness is as possible is little reduced. In principle, e.g. Thermoplastics or Duroplast used, a particularly preferred material for the Interlayer is elastomer.

According to one Alternative B is the interlayer part of one between the storage facility and the bearing device receptacle to be inserted intermediate part. The intermediate part can be one-sided or two-sided with the intermediate layer be coated. Here, the inventive idea is continued that the friction coefficient between the free surface of the Interlayer and the storage facility or the storage facility recording rather secondary. Rather, by the intermediate layer or the intermediate part ensures that the expansion differences of Storage facility and storage facility recording and the resulting Shear stresses are absorbed elastically.

According to one Alternative C is the rolling bearing as thrust bearing, in particular axial roller bearings formed. It was namely, surprisingly found that the use of an intermediate layer of plastic a hiking of the storage facilities realized in this case as bearing washers a thrust bearing in the bearing disc holder in the installed state in derogation. So far, the danger was not completely ruled out that the wandering of the thrust washers in the disc receptacle so strong pronounced is that strong contact with the bearing disk receptacle as well as fractures of Holding devices such as e.g. Holding lugs can occur. Especially with encapsulated thrust bearings can Radial slip components also lead to cage breaks. By using a Intermediate layer between the bearing disc and the disc holder at Axial bearings can these dangers in surprising simple manner, especially with encapsulated thrust bearings eliminated become.

According to one preferred embodiment According to the invention, the intermediate layer has a thickness of less than 100 μm, preferably smaller than 50 μm, in particular smaller than 30 microns on. The intermediate layer can on the one hand on the storage device, on the other hand on the storage facility receptacle and / or on the intermediate part be upset. It was surprisingly found that already in the mentioned relatively thin layers a sufficient absorption of the differences in expansion of storage facility and storage facility receptacle is reachable. The advantage of the low Thickness of the intermediate layer is that the bearing stiffness of the built-in rolling bearing is only slightly reduced by the intermediate layer.

at a special form of the invention is the intermediate layer of several Constructed individual layers, each having mutually separating planes, so that they are elastically displaceable in the direction of the shear stresses are. This special form ensures that the intermediate layer soft against Shear motions and at the same time stiff against compressive stresses is.

In a preferred structural implementation, the planar extension of the intermediate layer is aligned perpendicular to the type-related force introduction direction of the bearing. In radial roller bearings, the intermediate layer thus forms at least in sections a cylindrical or hollow cylindrical Form, whereas in Axialwälzlagern the intermediate layer is at least partially formed in the form of a ring or ring section. In particular, the intermediate layer may also be formed as a sleeve or sleeve segment.

at a preferred embodiment, at the rolling bearing as axial rolling bearings is formed with intermediate part, the intermediate part is as an annular disc realized. The annular disk is preferably dimensioned so that that the bearing device rest with its bearing surface over the entire surface on the intermediate part can. In particular, to save costs, the areal extent of the intermediate part on the bearing surface of the bearing device or on the contact surface be limited by storage facility and storage facility recording.

at another preferred embodiment, at the rolling bearing as a radial rolling bearing is formed, the intermediate part as a radial sleeve or sleeve segment realized in the load zone. The radial sleeve is mounted over the Inserted shaft or axle or inserted into the bearing seat, so that the inner ring or the outer ring on or in the radial sleeve can be mounted.

at both mentioned preferred embodiments, the intermediate part be formed of a homogeneous material, wherein the thickness of the homogeneous material is realized in particular greater than 0.1 mm. A possible Alternative is that the intermediate part consists of a or two-sided coated plate and / or a corresponding one Tube exists. The thickness of the plate or the tube should be off Stability reasons greater than 0.1 mm, wherein the coating thickness is again preferably smaller as 100 μm, preferably smaller than 50 microns and in particular less than 30 microns is trained.

Especially with regard to the training as an annular disc, it is possible unilaterally or use elastomer-coated plates as semi-finished products on both sides. This semi-finished product is already on the market today as a static seal available.

Further Features, advantages and effects of the invention will become apparent the following description of preferred embodiments of the invention and the attached Characters. Showing:

1 a schematic representation of a detail of a rolling bearing for illustrating the deformation of bearing device and bearing support receptacle;

2 in a schematic representation of a detail from 1 to illustrate the compression or extension of loaded partial areas;

3 an embodiment of a rolling bearing according to the invention in a schematic detail enlargement;

4 various alternatives for the realization of a strain-compensating intermediate layer for the rolling bearing in the 3 . 5 and 6 ;

5 an embodiment of the invention in the form of an axial roller bearing in detail cutout;

6 a further embodiment in the form of a radial roller bearing in cross-sectional view.

Same or corresponding parts or sizes in the figures, each with the same or corresponding reference numerals Mistake.

The 1 Illustrates a schematic representation of the deformations of a bearing device 1 sitting on a camp seat 2 is arranged while a rolling element 3 over the storage facility 1 rolls. During rolling, the rolling element is 3 subjected to a compressive force F.

In the in 1 As shown, the rolling element rolls along the arrow R from left to right. Due to the pressure load both the storage facility 1 as well as the camp seat 2 deformed, resulting in a contact area K results. The direction of the microwave is indicated by an arrow S.

The 2 shows the deformations and the resulting surface-parallel material expansions in the contact area K in a schematic enlargement, again the storage facility 1 or a section of it, the camp seat 2 and the rolling bearing 3 are shown.

The storage facility 1 is in a range I, which is below the rolling element 3 lies and the camp seat 2 is facing, stretched to train, so that ε> 0. By contrast, the regions IIa, b adjacent thereto have pressure expansions, ε <0.

In the opposite to the areas I, IIa and IIb edge regions on the free side of the bearing seat 2 the expansion behavior is pronounced in many areas.

in the central region, which is opposite to the region I, are pressure expansions before (ε <0), while in the edge areas facing the areas IIa, b, Tensile strains are present and ε> 0. Both the central area as well as the aforementioned peripheral areas are located in the contact area K.

Due to the different expansion behavior of the two mutually facing surfaces of storage facility 1 and camp seat 2 shear stresses occur in the contact area K, resulting in a relative displacement of the bearing device 1 and the camp seat 2 to lead. This relative movement of the bearing device 1 , Also called microwaving or slippage, in particular disk slippage, takes place predominantly in the direction of movement R of the rolling body 3 as it is in the 1 is illustrated with the arrow S. In addition to the main displacement in the direction of movement R, however, relative movements in the opposite direction can also occur locally.

Possible consequences of hiking the camp facility 1 is fretting corrosion and wear of the bearing device 1 or the camp seat 2 or the storage facility overlay. In Axialwälzlagern the hiking in the worst case leads to fractures of holding devices such as retaining lugs. Especially with encapsulated thrust bearings, such as in 5 radial slipping components can also lead to cage breaks, as then the cage between two bearing discs can not move freely. In radial roller bearings, there may be a displacement of the rings in the circumferential direction in the interference fit or in the clearance between the shaft and inner ring or between outer ring and housing or an axial migration of the rings and thus a malfunction of the bearing.

The 3 shows a first embodiment of the rolling bearing according to the invention in the form of a detail of a Axialwälzlagers 4 , In a similar representation as in the simulation images in the 1 and 2 is a rolling element 3 shown on a bearing disc 1 in one direction R rolls. In contrast to the preceding figures, however, is here between the bearing disc 1 and the corresponding bearing disk holder 2 an intermediate layer 5 arranged, which is adapted to the different expansion behavior of the surface areas of bearing disc 1 and bearing disc holder 2 compensate and prevent the resulting slip movements.

The intermediate layer 5 is formed as a thin intermediate layer which is as flexible as possible with regard to the shear modulus but which is at the same time as incompressible as possible. The choice of a low shear modulus has the advantage that the expansion differences in the contact area of bearing disc 1 and bearing disc holder 2 lead to low shear stresses in the intermediate layer. If the shear stresses in the intermediate layer are low, a low coefficient of friction is sufficient to prevent slippage of the intermediate layer. The material properties of the low compressibility and the structural design as a thin layer leads to the bearing stiffness of the rolling bearing 4 in the installed state through the intermediate layer 5 is only slightly reduced. Exemplary values or ranges for a beneficial material are: E in MPa (Young's modulus) v (transverse contraction number) 1.5-30 0.47-0.49995 (elastomer) 30-1000 0.35-0.49 (eg PA11) 1000-10000 0.3-0.4 (eg PA66)

The free surfaces or the free surface of the intermediate layer 5 are not specially treated.

The 4a to 4d show various embodiments for the realization of the intermediate layer 5 in a schematic cross-sectional view.

The 4a shows in a schematic enlargement of the storage facility 1 , wherein the intermediate layer on the storage device 1 attached, eg vulcanized, is. The thickness d of the intermediate layer 5 is less than 0.1 mm, preferably less than 50 μm, in particular less than 30 μm. A practical Rea In order to prevent slippage on an axial bearing washer with a typical thickness D1 of 0.5 mm to 1 mm or 1.2 mm in the running area of the rolling elements, it is intended to use a vulcanized, approximately 25 μm thick elastomer layer.

The 4b shows an intermediate part 6a which is used during assembly between storage facility 1 and warehouse reception 2 is to be positioned. The intermediate part 6a consists of a carrier material 7 , which on one or both sides with the intermediate layer 5 is coated. The carrier material 7 may be, for example, another plastic or a metallic material. The total thickness D2 of the intermediate part 6a is preferably less than 1 mm, for example less than 0.3 mm. A total thickness of D2 = 0.2 mm and a thickness of d = 25 μm gave good experimental results, in particular for thrust washers with a thickness of 0.5 mm up to 1 mm or 1.2 mm.

The 4c shows a further embodiment in the form of an intermediate part 6b made entirely of the material of the intermediate layer 5 is trained. For practical reasons, the thickness D3 of the intermediate part should 6b greater than 0.1 mm, but preferably less than 1 mm.

The 4d shows a further possibility of attachment of the intermediate layer 5 , wherein the intermediate layer 5 on the bearing seat 2 attached, in particular vulcanized.

A preferred choice for the material of the intermediate layer or for the intermediate part 6b is elastomer or another material with a similarly low shear modulus.

The 5 shows a schematic detail of a section of a Axialwälzlagers 7 which is on a pad 8th , in particular a bearing seat rests or is mounted. The axial rolling bearing 7 has a first bearing disc 9 and a second bearing disc 10 on, between which rolling elements 3 are rollably mounted in the form of rollers, so that first bearing disc 9 to the second bearing disc 10 can rotate relatively. Between second bearing disc 10 and the pad 8th is the intermediate layer 5 interposed, so that occurring shear stresses can be kept low by the intermediate layer as already explained. The intermediate layer 5 is as a coating on the base 8th facing side of the second bearing disc 10 or alternatively as a coating of the substrate 8th educated.

In other embodiments, rings with the in the 4b and 4c shown construction between second bearing disc 10 and underlay 8th be used. Alternatively or additionally, an intermediate layer 5 or a corresponding intermediate part between the first bearing disc 9 and the corresponding contact surface (not shown) used.

The 6 shows a built-in radial roller bearing 11 which is an outer ring 12 having. To avoid migration of the radial roller bearing 11 when installed is on the outside of the outer ring 11 encircling an intermediate layer 5 or an intermediate part according to the 4b and 4c arranged in the form of a sleeve. The intermediate layer 5 or the intermediate part is between the outer ring 11 and the camp seat 2 a housing arranged and used in the manner described, the migration of the radial rolling bearing 12 both in the radial direction and in the axial direction to reduce or eliminate.

1

Storage facility, -disc

2

bearing seat

3

rolling elements

4

thrust roller bearing

5

interlayer

6a

intermediate part

6b

intermediate part

7

support material

8th

document

9

first bearing disk

10

second bearing disk

11

radial bearings

12

outer ring

Claims (8)

Roller bearing ( 4 ; 11 ) with a first ( 9 ) and a second storage facility ( 10 ) and a plurality of rolling elements ( 3 ), the first ( 9 ) and the second storage facility ( 10 ) by means of the rolling elements ( 3 ) are rotatably mounted to each other and at least one intermediate layer ( 5 ) made of plastic, which is designed and / or adapted to move between one of the storage facilities ( 9 ; 10 ) and one to the storage facility ( 9 ; 10 ) to be arranged corresponding bearing fixture receptacle, characterized in that Alt. A the intermediate layer ( 5 ) consists of a plastic having a transverse contraction number greater than 0.4, preferably greater than 0.45, in particular greater than 0.48; and / or alt. B the intermediate layer ( 5 ) Part of an intermediate part to be inserted between the bearing device and the bearing device receptacle ( 6a , b) is; and / or alt. C the rolling bearing ( 4 ; 11 ) as a thrust bearing ( 4 ) is trained. Roller bearing ( 4 ; 11 ) according to claim 1, characterized in that the intermediate layer ( 5 ) has a thickness of less than 100 microns, preferably less than 50 microns, in particular less than 30 microns. Roller bearing ( 4 ; 11 ) according to claim 1 or 2, characterized in that the intermediate layer ( 5 ) consists of several individual layers having mutually separating planes. Roller bearing ( 4 ; 11 ) according to one of the preceding claims, characterized in that the intermediate layer ( 5 ) consists of elastomer and / or elastomer. Roller bearing ( 4 ; 11 ) according to one of the preceding claims, characterized in that the areal extent of the intermediate layer ( 5 ) is oriented perpendicular or substantially perpendicular to the design-related force introduction direction of the rolling bearing. Roller bearing ( 4 ; 11 ) according to one of the preceding claims with respect to alternative B, characterized in that the intermediate part ( 6a , b) is designed as an annular disc. Roller bearing ( 4 ; 11 ) according to claim 6, characterized in that the annular disc in the planar extension of the bearing surface of the bearing device ( 1 ) and warehouse reception ( 2 ) is or corresponds to this. Roller bearing ( 11 ) according to one of the preceding claims with respect to alternative A and / or B, characterized in that the intermediate part is designed as a radial sleeve.