EP2126386A1

EP2126386A1 - Bearing assembly

Info

Publication number: EP2126386A1
Application number: EP07846346A
Authority: EP
Inventors: Timur Dizlek; Josef Zylla; Arnd Heeg
Original assignee: Schaeffler KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2007-02-01
Filing date: 2007-11-17
Publication date: 2009-12-02
Also published as: DE102007004998A1; WO2008092415A1; KR20090104132A; WO2008092416A1; JP2010518324A; US20100061672A1

Abstract

The invention relates to a bearing assembly (2, 2', 2') for a shaft (18', 22) or similar that is to be axially guided with precision in a component, for example a housing (18', 22), said shaft being stressed to differing degrees and/or for different periods of time in the two axial directions. The bearing assembly (2) comprises a single-row angular contact ball bearing (4) and a single-row cylindrical roller bearing (6). The angular contact ball bearing (4) is designed to receive the greater main axial load (20) that is exerted during operation, whilst the smaller axial force that acts in opposition is absorbed by the cylindrical roller bearing (6) in addition to the radial forces. The quantity of equipment required to absorb the small axial force that in general is only exerted periodically can thus be kept to a minimum. In addition, a predefined axial play can be pre-set in the unit and a defined lateral ring overhang can be set between the inner and outer ring.

Description

Name of the invention

bearing arrangement

description

Field of the invention

The invention relates to a bearing arrangement for an axially exactly in a component to be guided shaft or the like, the conditions in the two Axialrichtun- different loads and / or long, comprising a substantially designed for receiving axial forces angular contact ball bearing assembly and a substantially for the inclusion of radial forces designed cylindrical roller bearing assembly.

Background of the invention

With the terms "component" on the one hand and "shaft or the like" on the other hand, all arrangements are to be detected in the broadest sense, in which one component is rotatably mounted relative to another. Examples include in a housing rotatably mounted shafts or hubs of fan wheels or transmission shafts. Bearing arrangements, both axial To absorb forces and radial forces are performed in many cases as a bearing sets with separate bearing assemblies for receiving the axial forces on the one hand and the radial forces on the other. In the case of units of the abovementioned type, relatively large axial forces frequently occur in operation in one direction of action, while in the opposite direction of action only occasionally, for example when the unit starts and ends, smaller axial forces generally occur.

A bearing arrangement is already known from DE 103 57 109 A1, in which an angular contact ball bearing arrangement is provided for receiving axial forces and a cylindrical roller bearing arrangement is provided for receiving radial forces. The angular contact ball bearing assembly is designed as a so-called four-point bearing, which can and should absorb axial forces in both axial directions. The angular ball bearing arrangement on the one hand and the cylindrical roller bearing arrangement on the other hand are structurally separated from one another in such a way that the former absorbs only axial forces and the latter only radial forces.

A general disadvantage of four-point bearings is seen in the fact that they are available by default only with a pressure angle of about 35 °, so that when acting on the bearing axial force a relatively large radial force component occurs only the rolling friction of the bearing and thus its wear increased, without bringing a benefit. In addition, four-point bearings are relatively expensive.

It is also already known to use an angular contact ball bearing pair in X- or O-arrangement as designed for the absorption of axial forces angular contact ball bearing assemblies. Such an arrangement is also relatively expensive and expensive because of the use of two angular contact ball bearings and also requires a relatively large axial length of the bearing. Both known bearing arrangements have in common that the technical effort to accommodate a generally only briefly acting and smaller in size force is just as large as the technical complexity for receiving the actual main operating force.

Object of the invention

The invention has for its object to provide a bearing assembly of the type mentioned in the O-term of claim 1, which is inexpensive to manufacture, has a relatively small length and which is better adapted than the known bearing assemblies to the particular operating conditions, in which in addition to acting in an axial direction main operating force generally occurs in terms of the duration and the size of lower opposing axial force.

Summary of the invention

The invention is based on the finding that the property of cylindrical roller bearings, even to a certain extent to be able to absorb axial forces, can be used to accommodate the lower in terms of time and size back pressure forces, so that the angular contact ball bearing assembly relieved of this task or can be released.

The invention is therefore based on a bearing arrangement for an axially exactly in a component to be guided shaft or the like, which is loaded in different degrees in the two axial directions, comprising a substantially designed for the absorption of axial forces Schrägkugellageran- order and a substantially for the Recording of radial forces designed cylindrical roller bearing assembly. It is inventively provided that the angular contact ball bearing assembly as a single row, for recording designed the stronger axial main operating force designed angular contact ball bearings, and that the cylindrical roller bearing assembly is designed as a single row, designed for receiving the weaker axial back pressure force and the radial force designed as a support bearing cylindrical roller bearing.

Accordingly, a single-row angular contact ball bearing is sufficient for receiving the main operating force. Such angular contact ball bearings represent commercially available, inexpensive machine elements that are available in different configurations. The lower in terms of their duration and size back pressure forces can be easily absorbed by a correspondingly modified cylindrical roller bearing, which means a slight increase in construction costs for the cylindrical roller bearing, but this is more than compensated by the simplification of the angular contact ball bearing assembly.

According to a preferred embodiment of the invention, one, namely the radially outer or the radially inner of the two bearing rings is formed in one piece and fixed in both axial directions relative to the associated component. It can thus transmit both the axial main operating force introduced via the angular contact ball bearing and the axial return pressure force introduced via the cylindrical roller bearing to the associated component. The respective other bearing ring is preferably formed from two individual rings, each of which is fixed in one of the axial force to be transmitted corresponding axial direction relative to the associated component (shaft).

A further preferred variant of the invention includes a unilaterally defined axial ring projection between the inner and outer ring, preferably on the angular contact ball bearing, which allows a defined axial shaft position relative to the housing relative.

In a first embodiment of the bearing assembly according to the invention the radially outer bearing ring is integrally formed, while the inner bearing ring consists of two individual rings. According to another variant, it can be provided that the inner bearing ring is in one piece and the outer bearing ring consists of two individual rings. Another refinement can provide that the outer or the inner bearing ring consists of two individual rings fixedly connected to one another, wherein these two individual rings may each have an annular groove in the region of the mutually facing end faces into which the two individual rings are fixed and flush with the surface without axial play connecting clip is inserted.

Another embodiment provides a one-piece inner ring with a separate flanged wheel. The two other bearing rings are also formed as individual rings and axially adjacent to the joint B. These various variants will be discussed in the following explanation of Ausfϋh- tion examples.

Thus, the angular contact ball bearing is not loaded by radial forces is provided according to a further embodiment of the invention that the bearing bore diameter of the angular contact ball bearing associated with individual inner ring defined larger than the diameter of the associated shaft portion.

In this context, it can also be provided, for example, that the outer diameter of the individual outer ring assigned to the angular contact ball bearing is a defined distance A forming smaller than the diameter of the associated section of the housing.

In order to be able to ensure a radial displacement of the individual ring of the angular ball bearing for an unconstrained centering of the same under load in the context of the radial play of the cylindrical roller bearing, it is provided according to a further embodiment that the difference or the distance A between the bearing bore diameter and the outside diameter the individual ring of the angular contact ball bearing and the associated portion of the shaft or the hollow shaft is greater than or equal to twice the value of the radial clearance of the cylindrical roller bearing.

A precise axial positioning of the second single ring relative to the first single ring is achieved in that it is measured after a first preliminary assembly of the second single ring, and that optionally an axial oversize or undersize of the second single ring is compensated by material removal or Beilegen a spacer ring ,

The rolling elements of the angular contact ball bearing and / or the cylindrical roller bearing are preferably guided in a cage to exclude a friction of the rolling elements to each other.

Further, it may be provided in a bearing assembly according to the invention that is formed on the side facing away from the angular contact ball end of the one-piece inner ring radially outwardly an annular groove into which a locking ring is inserted. This securing ring preferably acts as a disassembly safeguard so that the bearing arrangement can be manufactured by a bearing manufacturer as a ready-to-install bearing unit and can be disposed of as such. The retaining ring preferably holds such a distance C to the adjacent cylindrical rollers of the cylindrical roller bearing, that the locking ring and the cylindrical rollers do not touch.

Alternatively, the one-piece inner ring or outer ring of the cylindrical roller bearing may be provided at its end facing away from the angular contact ball bearing with a flange, which prevents loss of this one-piece bearing ring from the bearing assembly. Preferably may be provided in the construction described last, that the two individual rings of the two-part inner ring as already described after assembly of the cylindrical rolling elements by means of the clamp are firmly connected. Further, it is considered advantageous if it is provided that the two individual rings in the region of the mutually facing end faces radially outwardly each have an axial groove into which a two individual rings against relative rotation is used protecting each other locking element. In a further embodiment, the locking element may be formed as a feather key which is glued into the axial groove of one of the two individual rings and protrudes axially for engagement in the associated axial groove of the other single ring from the first-mentioned axial groove.

Finally, according to a further embodiment, it can be provided that the individual ring of the angular contact ball bearing and / or the single ring of the cylindrical roller bearing has at least one radial groove on its end face facing the respective other individual ring, in which lubricant can be taken up and forwarded.

Brief description of the drawings

The invention will be explained in more detail below with reference to the accompanying drawings in three embodiments. In this shows

1 shows a longitudinal section through a bearing arrangement with an angular contact ball bearing and a cylindrical roller bearing in O arrangement, which supports a central shaft in a housing,

Fig. 2 is a longitudinal section through a bearing assembly similar to FIG. 1, but in an X-arrangement, which supports a central shaft in a housing, and

Fig. 3 shows a bearing assembly in O arrangement similar to that in Fig. 1, but with an inner ring consisting of two firmly connected individual rings or of a ring and an axially flanged flange. Detailed description of the drawing

The two bearings have a common one-piece outer ring 8, on the inner surface of the raceways for the rolling elements of these two bearings, ie the balls 10 of the angular contact ball bearing 4 and Cylindrical rollers 12 of the cylindrical roller bearing 6, are formed. The inner bearing ring of the bearing assembly 2 is divided into a first single ring 14 for the angular contact ball bearing 4 and a second single ring 16 for the cylindrical roller bearing. 6

The bearing assembly 2 serves, for example, to radially and axially very precisely in a housing 22 a shaft 18, which must receive a larger axial force in the direction of the arrow 20 and occasionally and for a shorter period of time a smaller back pressure force in the opposite direction respectively. The main force occurring during operation is transmitted from the shaft 18 via the first single ring 14, the balls 10 and the outer ring 8 to the housing 22. The outer ring 8 must therefore be fixed against displacement in the direction of the arrow 20 in the housing 22, while the first single ring 14 is fixed against relative displacement on the shaft 18 against the direction of the arrow, so that the main force from the shaft 18 to the first Single ring 14 can be transferred.

The back pressure force acting in the direction opposite to the arrow 20 is correspondingly transmitted from the shaft 18 via the second individual ring 16 equipped with a radially outwardly directed rim 24, the cylindrical rollers 12 and the outer ring 8 with a radially inward-pointing rim 26 transferred to the housing 22, so that the outer ring 8 must be fixed in the direction opposite to the arrow 20 in the housing 22. In order to keep the angular contact ball bearing 4 free from radial forces, the diameter of the shaft 18 is smaller than the bore diameter of the individual ring 14, at least in the region receiving the first individual ring 14. The axial fixation of the first individual ring 14 is therefore achieved, for example, by a securing ring 32 inserted into a shaft groove guaranteed.

In order to ensure in any case that an axial force transmission is excluded from a single ring on the other single ring, so that the main force occurring during operation on the one hand and the opposite back pressure on the other hand is taken only by the designated bearing 4 or 6, is between the facing each other End faces of the individual rings 14 and 16, so provided in the joint designated B, a low axial play.

In order to achieve a precise axial position of the second individual ring 16 relative to the first single ring 14, the axial position of its outer end face is measured after a first preliminary mounting of the second individual ring 16 and an optionally present axial over- or undersize ± X by a corresponding Material removal or Beilegen a spacer compensated.

The reference numerals 28 and 30 cages for the balls 10 and the cylindrical rollers 12 are referred to, which guide these rolling elements and prevent friction of the same to each other.

Fig. 2 shows a second embodiment of a bearing assembly 2 'according to the invention, in which the angular contact ball bearing 4 has an X-arrangement and in which the bearing assembly 2 ^' supports a shaft 22 ^' in a housing 18'. In this construction, a one-piece inner ring 34 is used for the rolling elements 10 and 12 of the angular contact ball bearing 4 and the cylindrical roller bearing 6, while the outer rings 36 and 38 are formed as individual rings. In addition, to avoid a transmission of radial forces on the angular contact ball bearing largely safe, the outer peripheral surface of the individual ring 36 of the angular contact ball bearing 4 has a distance A from the inner circumferential surface of the housing 18 ^' , while the single ring 38 of the cylindrical roller bearing 6 with the inner circumferential surface of the housing 18 ^' non-positively connected is.

The transmission of an axial force in the main load direction 20 of the shaft 22 ^' in the bearing assembly 2 ^' takes place for example via a (not outlined) shaft collar on the side of the cylindrical roller bearing in the one-piece inner ring.

In order to ensure that the two individual rings 36 and 38 do not rotate relative to each other, or only insignificantly, relative to each other, they have axial grooves 40 and 42 in the region of their opposite end faces into which a key 44 is inserted as a locking means.

Fig. 2 also shows that the single ring 38 of the cylindrical roller bearing 6 has radially inwardly facing ribs 46 and 48, between which the cylindrical rolling elements 12 are arranged. In an annular groove 50 in the region of the free axial end of the common inner ring 34, a retaining ring 52 is inserted, which serves as a dismantling safeguard for the finished bearing assembly 2 ^' . The distance C of the securing ring 52 to the adjacent cylindrical rollers 12 is preferably selected so that they do not touch each other.

Comparatively small axial forces from the direction opposite to the main load direction 20 are transmitted from the shaft 22 ^' via suitable securing means (eg shaft nut, circlip, shaft collar, end cover, etc.) into the common inner ring 34', the cylindrical rollers 12 and finally over the rim 48 of the Single ring 38 in the housing 18 '(again via axial Securing means or a housing collar etc.).

A final variant is shown in Fig. 3, which shows a bearing assembly 2 ^" with an O-arrangement of the angular contact ball bearing 4. Also in this embodiment, the bearing assembly 2 ^" as in Fig. 1, the storage of a central shaft 18 in one rotatably fixed housing 22. The outer rings of the angular contact ball bearing 4 and the cylindrical roller bearing 6 lie against each other at the joint B and are formed as individual rings 36, 38, of which the single ring 38 of the cylindrical roller bearing 6 is positively and non-positively received in the housing 22, while the single ring 36 of the angular contact ball bearing 4 has such an outer diameter that a distance A between the outer circumferential surface of this single ring 36 and the inner circumferential surface of the housing 22 is determined. This distance A is so great that, taking into account the radial clearance of the cylindrical roller bearing 6, there is no radial transfer of force from the shaft 18 via the angular contact ball bearing 4 into the housing 22.

As with the example shown in FIG. 2 embodiment, FIG. 3 is also in the bearing assembly 2 ^"provides that the two outer rings 36 and 38 against each other against rotation. For this purpose, this in the region of its opposite end faces of axial grooves 40 and 42, respectively, in the as a locking means such as a key 44 is inserted.

In addition, a provided with the reference numeral 54 radial groove in the inner end face of the individual ring 36 of the angular contact ball bearing 4 is formed, which can be used for grease relubrication.

Next, the bearing assembly 2 ^" according to FIG. 3 is characterized in that the radially inner bearing ring 56 consists of two firmly interconnected individual rings 56 ^' and 56 ^" , each having an annular groove 62, 64 in the region of their facing end faces, in the one the two individual rings 56 ^' , 56 ^" fixed without axial play and radially flush inside binding clip 60 is inserted. As a result of this construction, both inner rings 56 ^' and 56 ^" can be produced and assembled individually so that they are firmly connected to each other only in a subsequent manufacturing step by means of the clamp 60.

Finally, Fig. 3 shows that the two-part inner ring 56 (56 ^' , 56 ^" ) is firmly connected at its cylindrical roller side free end with a flanged wheel 58. This flanged wheel 58 serves on the one hand as captive and on the other hand forwards axial forces, which counter to the main load direction 20 of the shaft 18 are carried in the bearing assembly 2 ^" . These comparatively small axial forces are then conducted via the cylindrical rollers 12 and the rim 46 of the radially outer individual ring 38 of the cylindrical roller bearing 6 into the housing 22.

In a further embodiment of this solution, the one-piece inner ring 56 (without grooves 62, 64 and without clip 60) can be realized with a loose flange 58. Here, an axial clamping of one-piece inner ring 56 plus loose flanged wheel 58 when mounted on the shaft (eg with shaft nut and mutual shaft collar) is required

_C M

LIST OF REFERENCE NUMBERS

2 bearing arrangement

bearing arrangement

2 ^" bearing arrangement

4 Angular contact ball bearings

6 cylindrical roller bearings

8 outer ring

10 balls

12 cylindrical rollers

14 First single ring on angular contact ball bearing radially inside

16 Second single ring on cylindrical roller bearing radially inside

18 wave

18 ^' case

20 arrow (axial force), main load direction

22 housing

22 ^' wave

24 board on single ring

26 board on the outer ring

28 cage

30 cage

32 circlip

34 One-piece inner ring

36 First single ring on angular contact ball bearing, radially outside

38 Second single ring on cylindrical roller bearing, radially outside

40 axial groove in the single ring 36th

42 axial groove in the single ring 38

44 locking element

46 board on the second single ring 38

48 board on the second single ring 38

50 annular groove on the one-piece inner ring 34th

52 retaining ring in the annular groove 50th 54 radial groove on the axially inner end face of the single ring 36th

56 two-piece inner ring

56 ^' First part of the inner ring 56

56 ^" second part of the inner ring 56 58 fixed flanged disc on the two-part inner ring 56" or loose flanged disc on the one-piece inner ring 56

60 clip

62 annular groove in the first part 56 ^'of the inner ring 56th

64 annular groove in the second part 56 ^"of the inner ring 56 A Radial game

B fugue

C Axial distance

± X oversize or undersize

Claims

Schaeffler KG Industriestr. 1 - 3, 91074 HerzogenaurachPatentansprüche

1. Bearing arrangement (2, 2 ^' , 2 ^" ) for an axially exactly on a component (18', 22) leading to the shaft (18, 22 ^' ) or the like, which is loaded differently strong and / or long in the two axial directions comprising an angular contact ball bearing arrangement designed essentially for absorbing axial forces and a cylindrical roller bearing arrangement designed essentially for receiving radial forces, characterized in that the angular contact ball bearing arrangement is designed as a single row angular contact ball bearing (4) designed to receive the stronger axial force, and in that Cylindrical roller bearing assembly is designed as a single row, designed for receiving the weaker axial force and the radial force designed as a support bearing cylindrical roller bearing (6).

2. Bearing arrangement according to claim 1, characterized in that in each case one, namely the outer or the inner of the bearing rings (8; 34) integrally formed and in both axial directions relative to the associated component (housing 22, shaft 18, 22 ^' ) is fixed in that each of the other bearing rings is formed from two individual rings (14, 16, 36, 38), each of the individual rings (14, 16, 36, 38) being in one of the axial direction corresponding to the axial force to be transmitted in relation to the associated component (shaft 18 , Housing 18 ^' , 22) is fixed, and wherein between the two individual rings (14, 16, 36, 38) has a joint (joint B) for the separate radial adjustment of the individual rings zueinan- is provided, which may be present in particular within the joint game, backlash or bias.

3. Bearing arrangement according to claim 2, characterized in that the outer bearing ring (8) is in one piece and the inner bearing ring of two

Single rings (14, 16) consists.

4. Bearing arrangement according to claim 2, characterized in that the inner bearing ring (34) is in one piece and the outer bearing ring consists of two individual rings (36, 38).

5. Bearing arrangement according to claim 2, characterized in that the outer or the inner bearing ring (56) consists of two firmly interconnected individual rings (56 ^' , 56 ^" ) or of a one-piece inner ring (56) plus flange (58), and that the other two bearing rings are formed as individual rings (36, 38).

6. Bearing arrangement according to claim 5, characterized in that the two individual rings (56 ^' , 56 ^" ) in the region of the mutually facing end faces each have an annular groove (62, 64) into which one of the two individual rings (56 ^' , 56 ^" ) without axial play firmly and flush connecting bracket (60) is inserted.

7. Bearing arrangement according to at least one of claims 2 to 6, character- ized in that the bearing bore diameter of the angular contact ball bearing (4) associated with the individual ring (14) is greater than the diameter of the associated portion of the shaft (18).

8. Bearing arrangement according to at least one of claims 2 to 6, character- ized in that the outer diameter of the

Angular contact ball bearing (4) associated with individual ring (36) forming a distance (A) smaller than the diameter of the associated Abschnit- tes of the housing (18 ', 22).

9. Bearing arrangement according to claims 7 or 8, characterized in that the difference (distance A) between the Lagerboh- insurance diameter or the outer diameter of the single ring

(14, 36) of the angular contact ball bearing (4) and the associated portion of the shaft (18) and the housing (18 ^' , 22) is greater than or equal to twice the radial clearance of the cylindrical roller bearing (6).

10. Bearing arrangement according to at least one of claims 2 to 9, characterized in that after accurate axial positioning of the second individual ring (16, 38) relative to the first single ring (14, 36) remaining axial over- or undersize (± X) to the outer end face of the second individual ring (16, 38) is compensated by removal or by enclosing a spacer ring.

11. Bearing arrangement according to at least one of claims 1 to 10, characterized in that the rolling elements (10, 12) of the angular contact ball bearing (4) and / or the cylindrical roller bearing (6) are each guided in a cage (28, 30).

12. Bearing arrangement according to at least one of claims 2 to 11, characterized in that at the direction away from the angular contact ball bearing (4) end of the one-piece inner ring (34) radially outwardly ne ring groove (50) is formed, into which a locking ring (52 ) is used.

13. Bearing arrangement according to claim 12, characterized in that the locking ring (50) as disassembly safeguard such a distance (C) to the cylindrical rollers (12) of the cylindrical roller bearing (6) that they do not touch.

14. Bearing arrangement according to at least one of claims 2 to 11, characterized in that a one-sided defined axial annular projection between the bearing inner ring and bearing outer ring is realized at the angular contact ball bearings (8-14, 36-34, 36-56 / 56 ') or at the cylinder roller bearing (8-16, 38-34, 38-56758), which has a defined axial

Shaft position relative to the housing allows.

15. Bearing arrangement according to at least one of claims 2 to 14, characterized in that the two individual rings (36, 38) radially outwardly each have an axial groove (40, 42) into which a single rings (36, 38) against relative rotation mutually protective locking element (44) is inserted.

16. Bearing arrangement according to claim 15, characterized in that the locking element (44) is designed as a feather key.

17. Bearing arrangement according to at least one of claims 2 to 16, characterized in that the individual ring (36) of the angular contact ball bearing (4) at its to the individual ring (38) of the cylindrical roller bearing (6) facing end side at least one radial groove (54) for the transmission of Has lubricant.