WO2011018490A1

WO2011018490A1 - Cage segment for a plastics cage of a rolling contact bearing and rolling contact bearing with a cage segment of this type

Info

Publication number: WO2011018490A1
Application number: PCT/EP2010/061727
Authority: WO
Inventors: Rudolf Zeidlhack
Original assignee: Schaeffler Technologies Gmbh & Co. Kg
Priority date: 2009-08-13
Filing date: 2010-08-12
Publication date: 2011-02-17
Also published as: DE102009037421A1

Abstract

The invention relates to a cage segment of a plastics cage for a rolling contact bearing and a rolling contact bearing with a plastics cage composed of segments. A cage segment of this type comprises at least two outer webs (17) and at least two connecting webs (18) connecting the outer webs (17) to each other, wherein a pocket (19) for receiving a rolling body (04) is formed in each case between the outer webs (17) and two connecting webs (18). According to the invention, the cage segments are guided in the rolling contact bearing by means of guide elements on restraining flange surfaces of the rolling contact bearing and/or on the rolling bodies.

Description

Name of the invention

Cage segment for a plastic cage of a rolling bearing and

Rolling bearing with such a cage segment

description

FIELD OF THE INVENTION The invention relates to a cage segment for a plastic cage according to the preamble of claim 1. Generic cage segments comprise two concentric circumferential webs and connecting webs arranged therebetween. In each case between two connecting webs and the peripheral webs a pocket for receiving a rolling element is formed. The inventions fertil particularly relates to a retainer segment for radial, axial and angular contact ball bearings, which are to be operable at operating temperatures up to 150 ⁰ C and have a pitch circle diameter greater than 500 mm. The invention also relates to a rolling bearing with a composite of segments plastic cage.

Such plastic cage segments are known from the prior art for some time and appreciated especially because of their low weight and cost-effective production. There are various solutions to allow swelling or thermal expansion of the cage material and thereby to prevent strong stresses in the cage and bearing, which are caused by the more thermally expanding plastic material of the cage than the usually made of steel remaining components of the bearing. DE 102 46 825 A1 describes a plastic cage, which consists of several segments. The cage described is particularly suitable for use in very large bearings with relatively small roles. The cage segments lie loosely against one another on their outwardly directed concave end faces. The dimensioning of the segments is to be selected so that in a gap-free juxtaposition of the segments between the adjacent end faces of the first and the last segment, a gap remains to accommodate a swelling and / or temperature-induced expansion of the segments. However, the potential gap between see the cage segments has the disadvantage that during operation in and between the cage segments higher forces occur, which can lead to a plastic deformation or cracking of the cage segments. Increased bearing friction, noise, temperatures and thus a shortened bearing life are the result.

From DE 10 2006 022 951 A1 and DE 10 2007 048 655 A1, plastic cage segments for large rolling bearings are known, which carry coupling elements on the end faces in order to achieve a play-related connection of the segments to the cage. Due to the even distribution of the play between the cage segments, mechanical stresses can be avoided. The described cage segments are designed for tapered roller bearings.

The object of the invention is to provide a cage segment for a plastic cage, in particular for a radial or axial deep groove ball bearing or an angular contact ball bearing (single or multi-row), whereby particular importance is attached to a simple assembly in a self-retaining bearings , Furthermore, an improved guidance of the cage in the rolling bearing is to be achieved. Another object is to provide a radial, axial or angular contact ball bearing with a plastic cage formed from segments ready. The object is achieved by a cage segment having the features of claim 1 and by a rolling bearing having the features of claim 6.

A cage segment according to the invention initially comprises in a known manner two outer webs, which are interconnected by connecting webs. For radial deep groove ball bearings, the outer webs are offset axially. Several segments can be connected to form a cage. For this purpose, the segments on their end faces coupling elements, which are each connected to the coupling element of the next segment. Preferably, a first coupling element are provided on a first end side and a second coupling element is provided on a second end side, which are in each case formed complementary to one another and can be connected to one another in a form-fitting manner. This makes a simple connection to a cage (ring) possible. Between the outer webs and two connecting webs each cage pockets are formed for receiving a respective rolling element. The connections at the coupling points are provided with a transition fit in the direction of a slight press fit. As a result, a swelling or temperature expansion of the cage formed by a plurality of segments can be accommodated in the coupling elements without mechanical stresses occurring. The fit has a size that corresponds to a swelling or thermal expansion of the cage material within a predetermined tolerance range. Depending on the cage segment, one or more pockets may be formed.

According to the invention, the guidance of the cage formed from the segments takes place via the flange surfaces of the bearing and / or via the rolling bodies. The contact of the rolling elements in the cage pocket is geometrically to be solved so that the rolling elements (eg the ball) touches the cage pocket to the right and left of its largest diameter. Half the ball diameter should run freely in the middle. As a result, there is no stripping of the lubricant. The advantages of the invention are to be seen in particular in that the assembly of the ball bearing with a plastic cage is easily possible. To do this, the balls in radial ball bearings are inserted via a filling hole between the two bearing rings and latched into the already inserted cage. When used with axial ball bearings, the rolling elements with the cage segments are inserted into the raceway of one bearing ring (horizontal bearing raceway, top raceway). Subsequently, the second bearing ring is placed with the track down on the rolling elements. The warehouse is now complete.

The segment is preferably held and guided in its position by means of guide knobs or webs both outwardly and inwardly toward the board diameters. In a preferred embodiment, the guide webs are formed in runner shape in order to improve the friction and the sliding on the board surfaces.

A roller bearing according to the invention, in particular a radial deep groove ball bearing, comprises an inner ring, an outer ring and rolling elements arranged in a cage between them, wherein the cage is composed of the previously detected segments. The outer ring has at least one filling hole over which the balls are filled into the bearing and snapped into the already mounted cage. The filling hole is provided in the bearing ring, which receives point load. During bearing assembly, this bearing ring is then installed and secured against rotation so that the filling hole is always in the load-free zone and remains. In an axial deep groove ball bearing shaft washer and housing washer are available accordingly.

Advantageously, the flange surfaces on the outer ring or on the outer disk or housing disk can be ground to improve the sliding properties. The person skilled in the art knows the variants of the geometric design of such cages, therefore details of these are not described in detail. went.

The outer webs are tuned in height so that there is still a sufficiently large free space through which a lubricant can be fed into the camp interior. At the connecting webs, the wall thicknesses are designed such that the rolling elements, especially the ball, only touch the cage in a small diameter range and the segment is only touched and guided by the balls in this area. As a result, the wiping of the lubricant is largely prevented. In an alternative embodiment, the guidance of the segments can also take place via the raceways of the rolling elements.

The cage segments according to the invention can of course also be used for two- or multi-row bearings with a corresponding modification.

The invention will be explained in more detail with reference to FIGS. 1 shows a schematic representation of a radial deep groove ball bearing with a rolling body guided, made of segments plastic cage according to the invention;

2 shows a schematic representation of a radial deep groove ball bearing with a board-guided plastic cage according to the invention, formed from segments;

3 shows a schematic representation of an axial deep groove ball bearing with a rolling body guided, made of segments plastic cage according to the invention; 4 shows a schematic representation of an axial deep groove ball bearing with a board-guided plastic cage according to the invention, formed from segments;

Fig. 5: four variants of radial coupling elements in spatial representations.

Fig. 1 shows a schematic representation of a detailed view of a radial deep groove ball bearing with a rolling body guided plastic cage. The bearing comprises in known manner an outer ring 01 and an inner ring 02, which are arranged concentrically to a bearing bore 03. Several balls 04 are arranged and held as rolling elements between the outer ring 01 and inner ring 02 in a raceway 06. The camp is self-holding. The balls 04 are held by a plastic cage, which is composed of several cage segments 07, at a distance.

The cage segment 07 comprises radial coupling elements 08, with which a plurality of cage segments can be connected to form a cage. The radial coupling elements 08 are designed in a basically known manner and will be explained in more detail below. The leadership of the cage is done by the balls 04 via guide elements, not shown.

The bearing has on its outer ring 01 on a filling hole 09 through which the balls 04 are filled during assembly of the bearing. When mounting the bearing, first the outer ring 01, the inner ring 02 and the cage, consisting of several assembled cage segments 07, mounted. Subsequently, the balls are inserted through the filling hole 09 in each case a cage pocket and locked there.

Fig. 2 also shows a schematic representation of a radial grooved ball bearing with a board-guided plastic cage. The warehouse has basically In addition, the same known structure, therefore, the same components carry the same reference numerals, as in Fig. 1st

The guide of the cage takes place in this embodiment on board surfaces 10 of the inner ring 02 and the outer ring 01. As guide elements here, in contrast to the embodiment shown in Fig. 1 guide webs 11 are formed to guide the cage on the board surfaces 10. Preferably, the guide webs 11 are formed skid-shaped to minimize frictional forces. In this variant, the ball has more play in the cage pocket.

3 and 4 show embodiments of the invention for axial deep groove ball bearings, each comprising a wave washer 12 and a housing plate 13 in a parallel arrangement in each case instead of the outer and inner ring. The bearing bore 03 is known to be arranged so that shaft washer 12 and housing plate 13 are offset in the axial direction. The cage segments 07 have the same structure as in the variants described above. FIG. 3 shows a rolling body-guided cage analogous to FIG. 1, while FIG. 4 shows an on-board cage analogous to FIG. 2.

In Fig. 5 different possibilities of radial coupling elements are shown. The figures each show a cage segment with outer webs 17, which are interconnected by connecting webs 18. Between the connecting webs 18 pockets 19 are formed for receiving a respective rolling element.

On one of the end faces 21 of the cage segment 17 coupling webs 22 are provided in extension of the outer webs (Fig. A). At the opposite end face, the outer webs 17 have coupling recesses 23, into which the corresponding coupling webs 22 of a further, identically constructed cage segment can engage. In the area of the coupling webs 22 Locking projections 24 are provided which engage in recesses 26 of the coupling recess 23 during assembly. The breakdown into such segments facilitates the production especially for large bearing diameters.

The various design options are shown in the other figures. Fig. B) shows that the coupling webs 22 have the locking recesses 26, in which locking projections 24 of the next cage segment can engage. In this embodiment, the latching projections 24 protrude in the longitudinal direction of the cage segment in each case to the outside. In the detailed illustration of Fig. B) it can be seen that the latching projection 24 within the latching recess 26 has a play s in the circumferential direction of the cage segment in order to accommodate expansions. Fig. C) shows an asymmetrical design of the radial coupling elements. At each of the end faces 21, a coupling web 22 and a coupling recess 23 are provided in each case. The coupling webs 22 carry the latching projections 24, while the recesses 26 are provided on the coupling recesses 23.

In Fig. D) a dovetail-like radial coupling point is shown, in which on the coupling webs 22 dovetail-shaped locking recesses 26 are formed, while at the coupling recesses 23 complementary shaped locking projections 24 are provided.

Guiding elements for ball guides are not explained in detail here, since those skilled in the art are familiar. LIST OF REFERENCE NUMBERS

01 outer ring

02 lnn

03 bearing bore

04 ball

05 -

06 career

07 cage segment

08 Radial coupling elements

09 filling hole

10 board area

11 guide bar

12 -

13 -

14 -

15 -

16 -

17 outer pier

18 connecting bridge

19 bag

20 -

21 front side

22 coupling bridge

23 coupling recess

24 latching projection

25 -

26 recess

Claims

claims

1. cage segment of a plastic cage for a rolling bearing, in particular for a large roller bearing, with at least two outer webs (17) and at least two outer webs (17) interconnecting connecting webs (18), wherein in each case between the outer webs

(17) and two connecting webs (18) a pocket (19) for receiving a rolling element (04) is formed, characterized in that the leadership of the cage segments in the rolling bearing by means of guide elements on the flange surfaces of the bearing and / or takes place on the rolling elements.

2. cage segment according to claim 1, characterized in that it comprises at its end faces (21) radial coupling elements (22, 23, 24, 26) for chaining together several cage segments to form a cage.

3. Cage segment according to claim 1 or 2, characterized in that the guide elements correspond to flange surfaces (09) of the rolling bearing, which are formed on one or both sides of the running surfaces on the inner ring (02) and / or on the outer ring (01).

4. Cage segment according to claim 3, characterized in that the guide elements as skid-shaped guide webs (11) facing the outer or inner ring (01, 02) are formed.

5. Cage segment according to one of claims 1 to 4, characterized in that it comprises locking elements for locking the rolling body in the cage segment during assembly.

6. Rolling, in particular radial or thrust ball bearings with a plastic cage, characterized in that the cage is composed of cage segments according to one of claims 1 to 5.

7. Rolling bearing according to claim 6, characterized in that it comprises an inner ring (02), an outer ring (01) and arranged therebetween in a cage rolling elements (04), wherein on the outer ring at least one filling hole for insertion of the rolling elements in the assembly of Rolling is provided.

8. Rolling bearing according to claim 6 or 7, characterized in that the outer ring (01) has ground flange surfaces.