EP2279358A2

EP2279358A2 - Rolling bearing cage

Info

Publication number: EP2279358A2
Application number: EP09753522A
Authority: EP
Inventors: Michael STADTMÜLLER
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2008-05-29
Filing date: 2009-05-19
Publication date: 2011-02-02
Also published as: DE102008025766A1; WO2009143806A2; WO2009143806A3

Abstract

A rolling bearing cage, for outer and inner rib rolling bearings, comprising cage webs that keep the rolling bodies at a distance and are fastened to front carriers, wherein the rolling bearing cage comprises rib regions having a maximum outside diameter or a minimum inside diameter of the rolling bearing cage for support on a bearing race and further comprises recesses between the rib regions for receiving lubricant.

Description

Name of the invention

Rolling bearing cage

description

Field of the invention

The Wälzkörperkäfig forms in addition to inner ring, outer ring and rolling elements a part of rolling bearings. The task of these cages is to guide the rolling elements. They ensure that the rolling elements do not touch each other or rub against one another in opposite directions and ensure even load distribution through uniform distribution of the rolling elements in the bearing. Furthermore, they hold the bearings in separable bearings, the rolling elements in the camp and thus prevent their falling out.

Cylindrical roller bearings, which are heavily stressed by acceleration and vibration, are usually equipped with an on-board cage. This achieves that the roller set with cage can be supported on the bearing ring. In this case, a support on the outer ring (outboard guide / outer ring guide) and on the inner ring (inboard guide / inner ring guide) is possible. The support is generally more effective the larger the area between the cage and the bearing ring. However, this results in a surface contact between the cage and bearing ring, which adversely affects a grease lubrication, since the lubricant supply can tear off at these points. The probability of this increases with the area being touched. A hot run of the bearing, increased wear and thereby premature bearing failure can be the result. In the prior art, therefore, a board guide in conjunction with a grease lubrication is not recommended.

In DE 195 30 903 A1 a rolling bearing is proposed as a solution to the said problem, the rolling elements are guided in a guided on the bearing outer ring one-piece cage. For lubricant supply is provided to place the contact zone between the cage and bearing outer ring to a diameter range which is greater than the smallest inner diameter of the rolling body raceway in the bearing outer ring. This optimization of the geometrical conditions at the bearing gap does not adequately solve the problem.

Previous other solutions to the problem mentioned consist in the provision of elaborate oil sump lubrication or Ölumlaufschmi- ments. However, these types of lubrication are complicated in design and thus expensive.

Object of the present invention is therefore to provide for camps with priority grease a board-cage, in which a grease supply in the area of the contact surfaces between the bearing ring and cage is enabled while maintaining the support of the cage and thus the roller set on the bearing ring.

This object is achieved by a roller bearing cage with the features of claim 1. Further advantageous embodiments are specified in the independent claims. In particular, the object is achieved by a roller bearing cage, for outside and inboard guided bearings, with the rolling elements at a distance holding attached to annular end supports cage webs, wherein the rolling bearing cage Bordbereiche with a maximum outer diameter or a minimum inner diameter of the rolling bearing cage for support on each bearing ring and between Having recesses for receiving lubricant on the board areas.

The rolling bearing cage according to the invention is guided outboard at Außenbordlagern and Innenbordlagem inside preferably on a bearing ring. The leadership of the rolling bearing cage takes place through the board areas. The cage webs of the rolling bearing cage keep the rolling elements at a distance and are preferably held by at least one inner and one outer end support. The roller bearing cage preferably has recesses for receiving lubricant in the support ring area. Further, recesses for receiving lubricant may be formed in the cage webs. The recesses are particularly preferably opposite as the circumference of the rolling bearing body or preferably equal to the circumference of the rolling bearing body arched. They can also be executed. The recesses are used in grease lubrication as fat deposits, which prevent tearing of the lubricating film.

In a preferred embodiment, the rolling bearing cage has recesses in the region of the cage webs, which preferably extend only to a maximum extent in the axial direction of the rolling bearing cage in the direction of the end carriers such as the rolling body retainer or extend as far as the stimuli carriers. The recesses in the area of the cage webs can also absorb lubricant and thus act as fat deposits, in order to prevent a tearing of the lubricating film in the rotating bearing. In order to avoid a weakening of the rolling bearing cage, it is advantageous if these recesses do not protrude into the region of the end supports. In accordance with a further advantageous embodiment, the recesses in each case particularly preferably merge with one, preferably with several transition radii, into the on-board regions. Preferably, the transition radii are greater than 1/50 of the maximum outer diameter of Wälzlager- cage. By this embodiment, the stripping of lubricant is reduced at the transitions between the board areas and recesses and thus prevents tearing of the lubricating film.

According to a preferred embodiment, a plurality of transition wheels between the board areas and the recesses merge into one another.

As a result, advantageous geometries can be realized, which reduce stripping of lubricant at the transitions between the recesses and the board areas. Furthermore, the sliding processes on the lubricant film can thus be optimized in such a way that the least possible frictional losses occur due to the lubricant.

According to a preferred embodiment, the recesses are formed in the end support, that in the axial direction of the rolling bearing cage on both sides next to the recesses or on one side of the recesses gene of the stimulator is formed continuously with the maximum diameter or the minimum diameter. In this embodiment, an edge of the rolling bearing body with a maximum outer diameter or in Innenbordführung remains with minimum inner diameter at least on one side next to the recesses. The recesses thus do not occupy the entire cross-section of the forehead support, but preferably at least one narrow edge remains. The rolling bearing cage can thereby despite the inventive lubrication on the entire circumference, z. B. be performed on a bearing ring. According to a preferred embodiment recesses are provided with different sized outer cross-sectional areas. Preferably, the largest outer cross-sectional areas are at least 50% larger than the smallest outer cross-sectional areas. Such a design of different sized recesses as lubricant depots has the advantage that for different rotational speeds of the rolling bearing cage and thus different Tribologiezustände in the interfaces, eg on the board areas, a customized lubricant supply can be adjusted.

According to a further advantageous embodiment, the recesses have a higher surface roughness than that of the on-board regions; this can also be achieved with a coating, for example. The rough coating supports the adhesion of lubricant in the recesses. The lubricant is better retained in the recesses and can thus be metered into the lubrication process.

In the following, further advantageous embodiments of the invention will be explained with reference to the drawings. Hereby shows:

Fig. 1 is a schematic perspective view of a rolling bearing cage according to the invention according to a first embodiment;

Figure 2 is a schematic perspective view of a rolling bearing cage according to the invention according to a second embodiment.

Fig. 3 is a schematic side view in the axial direction of a transition radius on a rolling bearing cage according to the invention. 1 shows a schematic three-dimensional view of a roller bearing cage 1 according to the invention according to a first embodiment. The rolling bearing cage 1 according to this embodiment is outboard. A roller bearing cage 1 is formed from two end supports 3, 4, which are connected by cage webs 30. The rolling bearing cage 1 has Wälzkörperaufnahmen 2 for receiving rolling elements (not shown). In this embodiment, the end supports 3, 4 have on-board regions 20 in the region of the substantially maximum diameter 5 of the roller body cage 1. The individual board areas 20 are separated in this embodiment by recesses 10 from each other. In the region of the recesses 10, the roller bearing cage 1 in this embodiment has a smaller than the maximum outer diameter 5, so that it is not guided outside in the region of the recesses 10. A minimum diameter 6 of the roller bearing cage is not provided with recesses 10 in this embodiment. The recesses 10 have an outer cross-sectional area 14. In this embodiment, the board areas 20 and the recesses 10 do not merge into one another like an edge but instead have a transition radius 12 therebetween.

In operation, the rolling element cage 1 according to the invention according to this embodiment is externally e.g. in a corresponding bearing ring (not shown) out. The guide is made by the board areas 20. The recesses 10 are used in grease lubrication as fat deposits that prevent tearing of the lubricating film. In order to prevent the lubricating film from being stripped off, the recesses 10 pass through transition radii 12 into the rim regions 20. This reduces the wiping effect.

FIG. 2 shows a schematic three-dimensional representation of a roller bearing cage according to the invention according to a second embodiment. In essence, this embodiment corresponds to the embodiment according to FIG. 1, but the recesses 10 are mutually arranged on the end supports 3, 4 not overlapping. The board areas 20 form as in the Previous embodiment, the maximum outer diameter 5 of the rolling bearing cage 1. In this embodiment, the recesses 10 are additionally provided with a coating 50.

Due to the fact that the recesses are not mutually overlapping, the rim areas 20, when viewed in summary, support a support, which is continuous around the circumference of the roller bearing cage 1, on a bearing ring. This results in a more stable support of the rolling bearing cage 1. Femer can be avoided by this arrangement possible lows vibrations on Wälzköperkäfig. For this purpose, an uneven distribution of the board areas or the recesses around the circumference is preferably provided for this purpose. This means that the length of the rim areas 20 or the recesses 10 or their angular position about the circumference of the roller bearing cage 1 is different at both end supports 3, 4. The coating 50, which is provided in the region of the recesses 10 in this embodiment, has a higher surface roughness than that in the on-board region, so that there grease can be absorbed on the surface. As a result, the grease is better kept in the area of the recesses 10 as fat deposits.

3 shows a schematic side view in the axial direction of a transition radius on a roller bearing cage according to the invention. In this embodiment, the board areas 20 go over radii 12 in the recesses 10. As a result, it is possible here that there is no transition with an edge between the two areas, which possibly wears off the lubricating film during operation. LIST OF REFERENCE NUMBERS

1 rolling bearing cage

2 Wälzkörperaufnahme 3, 4 end support

5 maximum outer diameter

6 minimum inner diameter

10 recess

12 transition radius 14 outer cross-sectional area of the recess

20 board area

30 cage bridge

50 coating

Claims

claims

1. Rolling bearing cage (1), for outer and Innenbordwälzlager, with the rolling elements at a distance holding on annular end supports (3, 4) fixed cage webs (30), wherein the rolling bearing cage (1) board areas (20) having a maximum outer diameter (5) or a minimum inner diameter (6) of the roller bearing cage for supporting on a respective bearing ring and between the board areas (20) has recesses (10) for receiving lubricant.

2. rolling bearing cage (1) according to claim 1, characterized in that the recesses (10) in the region of the cage webs (30) are arranged and in the axial direction of the roller bearing cage (1) only as far as possible in the direction of the end support (3, 4) as the Wälzkörperaufnahme (2) and / or extend only to the end supports (3, 4).

3. Rolling bearing cage (1) according to claim 1 or 2, characterized in that the recesses (10) each with one or more transition radii (12), in particular with transition radii (12) greater than 1/50 of the maximum outer diameter (5) in the Pass over board areas (20).

4. Rolling bearing cage (1) according to any one of the preceding claims, characterized in that the recesses (10) in the radial direction of the roller bearing cage a lower curvature than the curvature of the maximum outer diameter (5) of the Wälzlagerkä- figs (1) correspond or are oppositely curved.

5. Rolling bearing cage (1) according to one of the preceding claims, characterized in that a plurality of transition radii (12) merge into one another and / or in the recesses (10) and / or in the board areas (20) substantially asymptotically.

6. Rolling bearing cage (1) according to one of the preceding claims, characterized in that the recesses (10) are mutually arranged on a front support (3) and a front support (4) that they are not in the circumferential direction of the rolling bearing cage (1) overlap.

7. rolling bearing cage (1) according to one of the preceding claims, characterized in that the recesses (10) are formed in the end support (3, 4) that in the axial direction of the roller bearing cage (1) on both sides next to the recesses (10 ) or on one side of the recesses (10) of the end support (3, 4) is formed continuously with the maximum diameter (5) or the minimum diameter (6).

8. Rolling bearing cage (1) according to one of the preceding claims, characterized in that the recesses (10) have outer cross-sectional areas (14) smaller than 4 square millimeters, in particular smaller than 2 square millimeters.

9. Rolling bearing cage (1) according to any one of the preceding claims, characterized in that recesses (10) are provided with different sized outer cross-sectional areas (14), wherein the largest outer cross-sectional areas (14) are at least 50% larger than the smallest outer cross-sectional areas ( 14).

10. Rolling bearing cage (1) according to any one of the preceding claims, characterized in that the recesses (10) have a higher surface roughness than the board areas (20), in particular a coating (50) having a higher surface roughness than that of the board areas (20 ) exhibit.