WO2012143146A1

WO2012143146A1 - Bearing arrangement for a wheel bearing

Info

Publication number: WO2012143146A1
Application number: PCT/EP2012/051544
Authority: WO
Inventors: Bernhard Wilm; Johannes De Boer
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2011-04-20
Filing date: 2012-01-31
Publication date: 2012-10-26
Also published as: DE102011007719A1

Abstract

The invention relates to a bearing arrangement (1, 41) for a wheel bearing, comprising two bearings (3, 5, 43, 45) which are arranged spaced apart axially from one another on an axle (7, 47), with in each case one inner bearing ring (11, 29) and with in each case one outer bearing ring (17, 21), wherein the axle (7, 47) has, at one end, an axle shoulder (9, 49), on which the inner bearing ring (11, 29) of the first bearing (3, 5, 43, 45) is supported axially, wherein the outer bearing ring (17, 21) of the first bearing (3, 5, 43, 45) is supported axially via a connection element (19, 59) on the outer bearing ring (17, 21) of the second bearing (3, 5, 43, 45). This includes a clamping means (33, 73) which clamps the inner bearing ring (11, 29) of the first bearing (3, 5, 43, 45) with respect to the axle shoulder (9, 49). This ensures the required prestress for the reliable function of a bearing arrangement (1, 41), even with consideration of the settling and the wear of said bearing arrangement (1, 41).

Description

Name of the invention

Bearing arrangement for a wheel bearing

Description Field of the invention

The invention relates to a bearing assembly for a wheel bearing, comprising two axially spaced bearings arranged on an axis, each having an inner bearing ring, and each having an outer bearing ring, wherein the axis at one end has an axle shoulder, on which the inner bearing ring the first bearing axially supported, and wherein the outer bearing ring of the first bearing is axially supported via a connection element on the outer bearing ring of the second bearing.

Background of the invention

Bearing arrangements in wheel bearings of motor vehicles are used in particular for the exact guidance of stored vehicle wheels. The load of a wheel bearing and thus the bearing assembly is influenced by a variety of factors, of which, for example, the wheel load, the road conditions, the loads when cornering and as well as the average speed in the individual driving conditions are taken into account. The type of tires, as well as the braking and driving forces on the tire have an influence on the stress on the wheel bearing. Conventional bearing types such as tapered roller bearings, compact bearings or insert bearings with integrated seals have hitherto often been used to support the resulting requirements as well as possible. From DE 10 2007 060 562 A1 a wheel bearing for commercial vehicles is known. The wheel bearing is designed as a so-called insert bearing and consists essentially of a wheel hub, an axial end axle pivot and two arranged between the wheel hub and the journal journal bearings. The oblique roller bearings are employed against each other, wherein the rolling elements are formed by each in two rows with parallel Druckwinkelachsen juxtaposed ball rollers. As a result of their use, according to DE 10 2007 060 562 A1, the frictional resistance arising on the inner bearing rings can be reduced and the axial length of the inner bearing rings can be shortened.

Furthermore, from DE 10 2007 009 918 A1 a wheel bearing for supporting a wheel rotatable about an axis of rotation is known. The wheel bearing comprises a tapered roller bearing with a tapered roller row and an angular ball bearing with a first and a second ball row, which are guided between with a one-piece outer ring and a two-part inner ring. The partial stocks are also employed against each other. Here, a radially projecting flange is integrally formed on the one-piece outer bearing ring, which is provided for attachment to a vehicle frame.

Although a safe wheel bearing can be achieved according to the two above-described bearing arrangements, however, an undesired change in the bearing position due to subsidence during operation can not be ruled out safely.

OBJECT OF THE INVENTION It is therefore an object of the invention to provide a comparison with the prior art improved bearing arrangement, which enables a secure wheel bearing even at high loads. Solution of the task

The object of the invention is achieved by a Lageran- order for a wheel bearing comprising two axially spaced apart arranged on an axis bearing, each with an inner bearing ring, and each having an outer bearing ring, the axis having at one end an axle shoulder on the axially supporting the inner bearing ring of the first bearing, and wherein the outer bearing ring of the first bearing via a connecting element on the outer bearing ring of the second bearing is axially supported. Here, a tensioning means is provided, which braces the inner bearing ring of the first bearing relative to the axle shoulder.

The invention takes into account that a certain bearing position is necessary for safe wheel bearing. The bearing position of a bearing assembly is in this case basically achieved by hiring two bearings against each other, thereby ensuring the management task of the bearings and thus damage to the bearings, for example, as a result of tilting and edge stresses to be prevented.

In this case, however, it should be borne in mind that, despite preset bearing preload during operation, subsidence at the bearing points or even undesired signs of wear can frequently occur, as a result of which the employment of the bearings mutually changes in the worst case. Consequently, the desired bearing preload can no longer be maintained.

In order to prevent this and to prevent unwanted play of the components relative to one another, there is basically the possibility of bracing the components against one another in a block. However, the torque acting on the bearing components usually requires too high a preload in the bearing assembly, so that even here a trouble-free function can not be guaranteed. Furthermore, the manufacturing tolerances of the components are to be considered by means of which an influence on the bearing preload is possible. By a suitable definition of the manufacturing tolerances of the components, a desired clearance between the components can be set in a targeted manner. However, the determination of the component tolerances is usually associated with an undesirably high assembly and manufacturing costs, as well as high production costs. Overall, it is so far only possible with difficulty to provide a bearing position that ensures the required bias for the safe operation of a bearing assembly, taking into account the settlements.

In view of this, the invention recognizes that this problem can be overcome if a Verspannungsm ittel is used, which braces the inner bearing ring of the first bearing relative to the Achsschulter particular block.

By using a clamping element, the respective components can be joined within a tolerance range. This is thus a so-called set-right employment, with the use of the Verspannm ittels a balance of the manufacturing tolerances of the components is achieved. An exact control of the component tolerances is not necessary because with any combination of the manufactured components, the employment or the bias voltage at the bearings is within a mathematically predefined range. In other words, a complex measurement of the components as well as the use of additional compensation elements can be omitted. Also, a manual adjustment or the use of additional compensation elements can be omitted, since the components are already factory preset. This will reduces the assembly costs and also the production costs decrease.

The components of the bearing assembly can be made and joined accordingly within a relatively wide tolerance range, so that a complex and expensive measurement is accordingly avoidable. About the tension of the bearing components against each other by means of Verspannm itel the desired bearing position is then achieved during operation of a wheel bearing.

The bias is transmitted from the Verspannungsm mediate starting in a sense along an axially extending Abstützkette from the first camp to the second camp. The support chain is in this case particularly dependent on the combination or coordination of the height tolerance of the first bearing, the residue tolerance of the second bearing, the formation of the connecting element and the Achsschulter and the block bracing.

Overall, thus can be prevented by the employment coordination of the two camps in combination with the block tension of the inner bearing ring of the first bearing against the Achsschulter unwanted subsidence or at least balanced, so that the required bias of the bearing assembly can be guaranteed during operation.

Both the first bearing, a so-called outboard bearing, and the second bearing, a so-called inboard bearing, are each formed with an inner bearing ring, and an outer bearing ring. Rolling elements are guided between the bearing rings, which absorb radial and axial forces and at the same time allow the rotation of components mounted on the axle. The forces acting on the inner bearing ring forces are transmitted from this on the rolling elements on the outer bearing ring. Here, the friction and thus the power loss and wear should remain as low as possible, which can be achieved in particular by a lubrication of the bearing components or the bearing interior. As materials for the bearing rings usually hard materials such as metals or metal alloys for the individual bearing components are used, which withstand the operational requirements. For the rolling elements, for example, ceramic materials can be used.

The bearings may be formed, for example, as angular contact ball bearings or tapered roller bearings. Either both bearings can be of the same bearing type. Alternatively, when combining an angular contact ball bearing with a tapered roller bearing, for example, the advantages of both types of bearings can be combined in one unit. The rows of balls of an angular contact ball bearing offer, for example, a very low friction, whereas the use of a tapered roller bearing leads to a very high load capacity. In principle, however, other types of bearings for use in a wheel bearing or in a bearing assembly for a wheel bearing are possible.

The axis on which the bearings are arranged axially spaced from each other, is formed at an axial end, the so-called stub axle, with an axle shoulder. The axle shoulder or the so-called stub axle is designed in the form of a radially extending fold. The Achsschulter thus provides a contact surface available, which serves the axial abutment of a pushed onto the axle bearing ring.

The inner bearing ring of the first bearing is supported correspondingly axially on the Achsschulter the axis. In other words, the inner bearing ring of the outboard bearing is braced by means of the Verspannm itel with respect to the Achsschulter. The forces acting on the inner bearing ring forces are transmitted from this on the rolling elements on the outer bearing ring of the first bearing. This in turn is supported axially via the connecting element on the outer bearing ring of the second bearing. The support can for example also take place via a shoulder for abutment or via a collar, wherein the means for supporting or abutment is expediently designed as a part of the connection element. The connection element is designed for example as part of a wheel hub. Alternatively, the connection element may for example also be designed as a so-called rim connection part for fastening a wheel. Preferably, the connection element consists of a stable and wear-resistant material. For this purpose, as with the bearing components, especially metals or metallic alloys are suitable.

The power transmission of the outer bearing ring of Outboardlagers on the outer bearing ring of the inboard bearing via the connection element. For this purpose, the connection element expediently has a further contact surface, which allows an abutment of the outer bearing ring of the inboard bearing. This counter bearing additionally prevents undesired axial displacement or slippage of the bearing components relative to one another and along the axis.

Starting from the outer bearing ring of the inboard bearing, the force is transmitted via the rolling elements on the inner bearing ring, which in turn is counteracted on the axis.

Overall, the force that is introduced by the Verspannmteltel at the end of the axis in the bearing assembly, thus along the Abstützkette, ie from the Outboardlager on the connection element and the inboard storage, forwarded and allows the secure positioning of the components with the desired bias the bearings.

In an advantageous embodiment of the invention, the Verspannungsm ittel is formed as a mother. This embodiment allows a simple clamping of the components against each other. The nut can be screwed at one end of the axle to a thread formed there and come to rest on the inner bearing ring of Outboardlagers. In other words, the inner bearing ring of Outboardlagers is braced by the mother on the axle shoulder block. The required preload can be determined by the fixed pulling the mother to be set. Here, the maximum torque for fixing the nut is suitably adapted to the respective areas of the component tolerances of the bearing components and the respective contact surfaces.

In a further advantageous embodiment, the connecting element has a first hub collar on which the outer bearing ring of the first bearing is axially supported. The axial support on the hub collar allows the transmission of power from the bearing ring on the connection element and also prevents axial slippage of the bearing components outside the limits of the permissible game. The hub collar in particular circumscribes the connection element in full circumference, so that a contact surface is available for this at any point along the circumference of the bearing ring. Furthermore, the width of the hub collar is expediently variable, so that, for example, an adjustment or adjustment with respect to the required preload and the acting forces can already take place here before assembly.

Conveniently, the connecting element has a second hub collar, which is supported axially on the outer bearing ring of the second bearing. In other words, the second hub collar allows the support of the connection element on the outer bearing ring of the inboard bearing. The axial support on the hub collar allows the transmission of power from the bearing ring on the connection element and also prevents axial slippage of the bearing components of the inboard bearing. Also, the second hub collar extends in the radial direction and surrounds the connection element in particular full circumference. As already described above, the second hub collar also prevents axial slippage of the bearing components. The width of the hub collar is variable taking into account the other components or their tolerance ranges and with regard to the required bias.

Preferably, the or each hub collar is made in one piece with the connection element. Due to the one-piece production, a secure counter bearing or axial support of the bearing rings of the bearings can be ensured. Farther the bearing rings coming into contact with the or each hub collar are axially limited in their movement.

Preferably, the inner bearing ring of the second bearing is supported axially on a contact surface of the axis. During operation, the inner bearing ring of the inboard bearing is pressed against the contact surface via the axial forces acting through the tensioning element, this preventing the bearing from being displaced along the axis. Thus, on the one hand the bearings are axially limited on both sides by the tensioning means and on the other hand by the contact surface on the axle.

Advantageously, the first bearing is designed as an angular contact ball bearing. Angular contact ball bearings have in the direction of the bearing axis offset from each other arranged raceways in the inner and outer ring. They are particularly suitable for bearings that have to absorb combined loads, ie simultaneously acting radial and axial loads. The axial load capacity of the angular contact ball bearings increases with the size of the so-called contact angle. The angle of contact is the angle which the connecting line of the two contact points between the ball and the raceways encloses with the radial plane and under which the load is transmitted from one raceway to the other. An angular contact ball bearing can be either open or sealed.

Preferably, the second bearing is designed as a tapered roller bearing. Bevel roller bearings, as well as angular contact ball bearings, have high radial and one-sided axial loads. A tapered roller bearing usually consists of solid outer and inner bearing rings with tapered Wälzkörperlaufbahnen. As rolling elements tapered rollers are used, which are guided in cages. The bearings are not self-retaining, so that and inner bearing ring with the tapered rollers and the cage can be installed separately from the outer bearing ring. For axial countermeasure usually a second bearing is necessary, which is then arranged in mirror image. In the single row tapered roller bearings results in the Bearing clearance or preload only after installation and depends on hiring against a second bearing, which takes over the countermeasure.

As already mentioned, of course, other types of bearings can be used for both the inboard warehouse and the outboard warehouse if this is required. Thus, for example, the use of two axially adjacent and against each other employed tapered roller bearings is conceivable, in particular because of their high load capacity and wear resistance. Conveniently, at least one sealing element for sealing the or each bearing is included. The sealing element is for this purpose attached in particular to a bearing ring. The bearing interior can be sealed in the axial direction on both sides by a sealing element. This variant offers a substantially complete protection of the bearing interior in a dirt-intensive environment. Since the sealing element is preferably made of a material such as a plastic, which withstands high loads and temperatures during operation.

Short description of the character

In the following the invention will be explained in more detail with reference to a drawing. Show

Fig. 1 shows a bearing assembly for a wheel bearing with an angular contact ball bearing and an axially adjacent tapered roller bearing in a longitudinal section, and

Fig. 2 shows a bearing assembly for a wheel bearing with two axially adjacent tapered roller bearings in a longitudinal section. Detailed description of the drawing

In Fig. 1, a bearing assembly 1 with an angular contact ball bearing 3 and a tapered roller bearing 5 is shown in a longitudinal section. It is thus a combined bearing assembly. 1 The two bearings 3, 5 are set against each other and arranged axially spaced from each other on an axis 7. By combining the angular contact ball bearing 3 with the tapered roller bearing 5, the advantages of both types of bearings can be effectively utilized. The axis 7 has at its outer axial end, the so-called stub axle, an axle shoulder 9. The Achsschulter 9 is formed as a radially ersteckende fold and provides the contact surface for the made of a bearing steel inner bearing ring 1 1 of the angular contact ball bearing 3 available. The inner bearing ring 1 1 is supported in accordance with axially on the Achsschulter 9.

The force which is transmitted from the axis 7 to the inner bearing ring 1 1 of the angular contact ball bearing 3 is then transmitted from the latter via the rolling elements 13, 15 to the outer, also made of a bearing steel bearing ring 17. As rolling elements 13, 15 balls are used in the present case of a ceramic material.

From the outer bearing ring 17 of the angular contact ball bearing 3, the force is transmitted to the connection element 19 made of a metallic material. The connecting element 19 is designed as a wheel hub and allows the attachment of a wheel, which is not shown here, however. Starting from the connecting element 19, the forces acting during operation are transmitted to the outer bearing ring 21 of the tapered roller bearing 5. For power transmission, the connection element 19 has two hub collars 23, 25, which are each manufactured in one piece with the connection element 19. Both hub collars 23, 25 completely surround the connection element 19, thus enabling a uniform counterpart at any point along the circumference. storage or axial support of the respective outer bearing ring 17, 21st

The first hub collar 23 in this case represents the axial contact surface for the outer bearing ring 17 of the angular contact ball bearing 3. The outer bearing ring 17 of the angular contact ball bearing 3 is thus supported axially on the hub collar 23.

The second hub collar 25 serves to bear the outer bearing ring 21 of the tapered roller bearing 5, wherein the outer hub collar 25 is axially supported on the outer bearing ring 21 of the inboard bearing 5. In addition to the axially secure positioning, the force is thus transmitted from the connecting element 19 to the outer bearing ring 21 via the hub collar 25.

From the outer bearing ring 21 of the tapered roller bearing 5, the forces on the trained as a tapered rolling elements 27 on the inner bearing ring 29 Ü transferred. This in turn is supported axially on a contact surface 31, which is introduced in the form of a radially extending fold in the axis 7.

In order to fasten all the components together with the required preload and to ensure a safe operation of the bearing assembly 1, a tensioning means 33 designed as a central nut is attached to the outer axial end of the shaft 7. The nut 33 is screwed onto the end of the shaft 7 to a thread and braced relative to the Achsschulter 9.

Through the use of the nut 33, the respective components can be joined within a tolerance range, without an accurate knowledge of the manufacturing tolerances is necessary.

In addition, the tapered roller bearing 5 with two sealing elements 35, 37 is formed, which limit the bearing interior in the axial direction on both sides. The sealing elements 35, 37 provide the required protection of the bearing components against undesired contamination as well as the loss of lubricant. In Fig. 2, a further bearing assembly 41 is shown for the wheel bearing of a vehicle. The bearing assembly 41, as well as the bearing assembly 1 in Fig. 1 two mutually employed bearings 43, 45 on. In contrast to FIG. 1, however, no combined bearing arrangement 1 is shown here, but a bearing arrangement 41 with two identical bearing types is shown. Both the inboard bearing 43 and the outboard bearing 45 are formed as tapered roller bearings, which are arranged against each other axially adjacent arranged on an axis 47. The bearing components are each made of a temperature-resistant metallic material.

The axis 47, as well as in Fig. 1, an axle shoulder 49, on which the inner bearing ring 51 of the first tapered roller bearing 43 is counter-supported or on which this is axially supported. The force is transmitted from the inner bearing ring 51 to the outer bearing ring 57 of the outboard bearing 43, and from there, via the connecting element 59, to the inboard bearing 45 via the rolling elements 53, which are formed as tapered rollers.

For this purpose, the connection element 59 according to FIG. 2 also has two circumferential hub collars 63, 65 manufactured in one piece therewith, which serve as an abutment for the outer bearing rings 57, 61, respectively. Furthermore, the hub collars 63, 65 function as an axial securing by preventing undesired slippage of the bearing rings 57, 61 in the axial direction. From the outer bearing ring 61 of the inboard bearing 45, the forces are transmitted to the inner bearing ring 69 via the roller bodies 67, which are likewise designed as tapered rollers. This in turn is supported on a contact surface 71, which is introduced in the form of a radial fold in the axis 47. As in FIG. 1, a tensioning means 73 designed as a central nut is included. The nut 73 is screwed to clamp the inner bearing ring 51 of the inboard bearing 43 at the outer end of the shaft 47 to a thread, not shown. In this way, the inner bearing ring 51 is ge clamped opposite the Achsschulter 49 and allows a secure employment of the bearings 43, 45th

In addition, the inboard bearing 45 is axially sealed on both sides by means of two sealing elements 75, 77 against undesired contamination and lubricant loss.

For the further detailed description of the individual bearing components, reference is made at this point to the description of the bearing arrangement 1 according to FIG. 1, which in the present case can be transferred analogously to the bearing components of the bearing arrangement 41.

List of reference numbers

I bearing arrangement

3 bearings

5 bearings

7 axis

9 axle shoulder

I I inner bearing ring

13 rolling elements

15 rolling elements

17 outer bearing ring

9 connection element

21 outer bearing ring

23 Hubbands

25 hub collar

27 rolling elements

29 inner bearing ring

31 contact surface

33 tensioning device

35 sealing element

37 sealing element

41 bearing arrangement

43 bearings

45 bearings

47 axis

49 axle shoulder

51 inner bearing ring

53 rolling elements

57 outer bearing ring

59 connection element

61 outer bearing ring

63 Hubbands

65 Hubbands Rolling element Inner bearing ring Contact surface Clamping element Sealing element Sealing element

Claims

claims

1 . Bearing arrangement (1, 41) for a wheel bearing, comprising two bearings (3, 5, 3, 5) arranged axially spaced from one another on an axle (7, 47).

43, 45) each having an inner bearing ring (1 1, 29), and each having an outer bearing ring (17, 21), wherein the axis (7, 47) at one end an axle shoulder (9, 49), at the the inner bearing ring (1 1, 29) of the first bearing (3, 5, 43, 45) is axially supported, wherein the outer bearing ring (17, 21) of the first bearing (3, 5, 43, 45) via a connection element (19, 59) on the outer bearing ring (17, 21) of the second bearing (3, 5, 43, 45) axially supported, and wherein a tensioning means (33, 73) is included, which the inner bearing ring (1 1, 29) of the first bearing (3, 5, 43, 45) relative to the axle shoulder (9, 49) braced.

2. Bearing arrangement (1, 41) according to claim 1,

wherein the tensioning means (33, 73) is formed as a nut.

3. bearing arrangement (1, 41) according to claim 1 or 2,

wherein the connecting element (19, 59) has a first hub collar (23, 63) on which the outer bearing ring (17, 57) of the first bearing (3, 43) is axially supported.

4. Bearing arrangement (1, 41) according to any one of the preceding claims, wherein the connecting element (19, 59) has a second hub collar (25, 65) axially on the outer bearing ring (21, 61) of the second bearing (5, 45 ) is supported.

5. bearing arrangement (1, 41) according to claim 3 or 4,

wherein the or each hub collar (23, 25, 63, 65) is made in one piece with the connecting element (19, 59). Bearing arrangement (1, 41) according to one of the preceding claims, wherein the inner bearing ring (17, 57) of the second bearing (5, 45) on a contact surface (31, 71) of the axis (7, 47) is axially supported.

Bearing assembly (1, 41) according to any one of the preceding claims, wherein a bearing () is formed as an angular contact ball bearing.

Bearing arrangement (1, 41) according to one of the preceding claims, wherein a bearing (3, 43) is designed as a tapered roller bearing.

Bearing assembly (1, 41) according to any one of the preceding claims, wherein a sealing element (35, 37) for sealing the or each bearing (3, 5, 43, 45) is included.