EP2668410A1

EP2668410A1 - Rolling bearing

Info

Publication number: EP2668410A1
Application number: EP11788504.6A
Authority: EP
Inventors: Peter Friedrich; Michael Krüger; Steffen Säbsch; Heinz Schäfers; Matthias Fick; Manfred Winkler; Johannes ENDERS
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2011-01-26
Filing date: 2011-11-30
Publication date: 2013-12-04
Also published as: CN103328838B; US20130266251A1; US9206845B2; KR20130140834A; DE102011003211A1; KR101911392B1; WO2012100867A1; CN103328838A

Abstract

The invention concerns a rolling bearing with a rolling bearing cage (1) having a plurality of rolling element pockets (2) arranged in at least one row to receive at least one row of rolling elements, wherein the rolling bearing cage (1) consists of two lateral rings (3) and a plurality of crosspieces (4) connecting them, between which crosspieces are formed the rolling element pockets (2), and having at least one empty pocket (5). In order to achieve cost-effective manufacture of the rolling bearing cage (1) with the fewest possible changes as compared to a rolling bearing cage fully populated with rolling elements, provision is made according to the invention that the rolling bearing cage (1) is equipped with fewer rolling elements in one row than corresponds to the number of rolling element pockets (2), causing the rolling bearing cage (1) to have empty pockets (5) without rolling elements in the at least one row of rolling element pockets (2). The empty pockets (5) can be implemented in a simple manner by omitting one or more rolling elements, so that storage spaces for lubricant are created. Furthermore, the empty pockets (5) can be formed by targeted shaping in such a manner that a conveying or pumping action is produced in at least one direction of rotation. The invention also concerns a method for producing such a rolling bearing cage.

Description

Name of the invention

Rolling bearing Field of the invention

The present invention relates to a rolling bearing having a roller bearing cage with a plurality of arranged in at least one row rolling bearing pockets for receiving at least one row of rolling elements, wherein the rolling bearing cage consists of two side rings and a plurality of these connecting transverse webs, between which the rolling body pockets are formed, and at least one empty bag. Moreover, the invention relates to a method for producing such a roller bearing cage. Background of the invention

Such a cage for a rolling bearing is described in DE 10 2005 027 186 A1. The roller bearing cage consists of a cylindrical annular body on which at least one row of circumferentially spaced rolling elements pockets for receiving rolling elements is formed, and on which an axially adjacent row of empty pockets, for example, for receiving lubricant, is formed.

The disadvantage is that this known roller bearing cage builds wider than a conventional single or multi-row Wälzkörperkäfig when the usual length of the rolling elements is maintained, or that the length of the rolling elements must be reduced to compensate for the additional axial space requirement of the empty pockets. Thus, the production cost for this known roller bearing cage is increased, since the material requirement is increased, additional processing effort for the empty pockets is required, and the load rating of equipped with this bearing roller bearing is reduced with shortened rolling elements. Object of the invention

Against this background, the invention is based on the object to provide a rolling bearing with a roller bearing cage, which is easy to manufacture, requires no greater cost of materials than a conventional roller bearing cage, in its dimensions compared to a conventional roller bearing cage is unchanged and, accordingly, has virtually the same properties, and allows a targeted supply of lubricant. In addition, the invention has for its object to provide a method for producing such a rolling bearing cage.

Summary of the invention

To achieve this object, the invention is based on a rolling bearing with a roller bearing cage having a plurality of arranged in at least one row rolling elements pockets for receiving at least one row of rolling elements, wherein the rolling bearing cage consists of two side rings and a plurality of these connecting crossbars, between which the rolling body pockets are formed, wherein the rolling bearing cage has at least one empty pocket. According to the invention it is provided that the roller bearing cage is equipped in a row with fewer rolling elements, as it corresponds to the number of Wälzkörpertaschen, whereby the Wälzkörperkäfig in the at least one row of Wälzkörpertaschen at least one empty pocket without a rolling element.

The roller bearing cage can also be manufactured with respect to a roller bearing cage, whose rolling element pockets are all equipped with rolling elements, but at least one rolling element pocket is not equipped with a rolling element and thus results in an empty pocket. This empty bag is used for receiving and / or distribution of lubricant.

It is also possible to form several empty pockets by omitting rolling elements, the maximum number of empty pockets preferably being is limited to that only every second rolling element pocket is equipped with a rolling element.

In order to produce a specific conveying or pumping action of the empty pockets of the cage in at least one direction of rotation of the same, according to a further development of the invention, the empty pockets can have a different form from the rolling-body pockets. In principle, the empty pockets can have any desired geometry, for example oblique, conical, spherical, non-uniform, asymmetrical, smaller or larger than the rolling-body pockets. Its concrete geometry can be determined solely by the saving of manufacturing time and / or its pumping action, wherein a reworking of an empty bag made by a first production step is avoided.

If, for example, the rolling-body pockets are produced by mechanical processing, by firstly incorporating the rolling-body pockets at regular intervals in the circumference of the rolling bearing cage by means of a cylindrical milling cutter, the pockets provided for receiving rolling bodies can then be provided with undercuts by means of a further shaping milling tool, around the rolling bodies to prevent it from falling out before assembly and to guide it accurately during operation. The at least one empty pocket does not have such undercuts, which saves manufacturing costs.

The Wälzkörperkäfig according to the invention may preferably be made in one piece from plastic and be designed to receive bearing needles of a needle bearing.

In order to achieve the stated object, a method for producing a roller bearing cage of the type described above is furthermore proposed, according to which at least the undercuts in the area of the rolling body pockets are produced by means of a form milling cutter. In this case, the rolling-element pockets can be used in a first step by means of a cylindrical milling cutter. edited and the empty pockets are incorporated by means of the same cylindrical milling cutter.

The complete mechanical processing of the Wäizkörpertaschenaschen and the empty pockets by means of milling cutter is preferably used when the rolling bearing cage made of solid metal, such as brass.

When the rolling bearing cage is made of plastic, it is possible to form the rolling-element pockets and the empty pockets by slides arranged in the injection-molding tool. Since this makes the injection mold is very expensive and costly, this type of production is only for very large numbers of advantage.

If the rolling body pockets are machined radially by means of the cylindrical milling cutter and the empty pockets are incorporated into the cage blank by means of the same cylindrical milling cutter, empty pockets, whose changes or center line in the circumferential direction with an outgoing radius from the cage longitudinal axis, are obtained form. As a result, depending on the direction of rotation, a pumping action directed radially inwards or radially outward for the lubricant can be achieved. The center line of an empty pocket is understood to mean the axially extending middle between the two axially oriented walls of the empty pocket.

The mold cutter used for producing the undercuts of the rolling body pockets is guided in the rolling body radially along the side walls of the rolling elements produced by means of the cylindrical milling cutter, whereby it is possible first by means of the cylindrical milling all pockets in the rolling bearing cage including the deraxierten empty pockets to produce, then subsequently in the same way, work the undercuts into the rolling-element pockets by means of the form-milling cutter.

It is also possible to produce the Wälzkörpertaschen by means of the cylindrical cutter and the undercuts by means of the form cutter simultaneously when the Milling head for receiving and driving two parallel cylindrical cutter and a spaced apart, radially directed form cutter is set up.

Short description of the drawing

A preferred embodiment of the inventively embodied rolling bearing will be explained in more detail with reference to the accompanying drawings. 1 shows a radial section through a roller bearing cage according to the invention with machining tools during its production, and

Figure 2 is a plan view of the rolling bearing cage according to the invention according to Figure 1, which is intended for receiving Wälzlagemadeln.

Detailed description of the drawing

The rolling bearing cage 1 shown in Figures 1 and 2 is a solid cage for needle roller bearings, in particular for Losradlagerung in a transmission. The rolling bearing cage 1 may be made of plastic or metal, in particular brass. The rolling bearing cage 1 has rolling body pockets 2 and at least one empty pocket 5, which are formed between two parallel side rings 3 connecting transverse webs 4. The rolling-body pockets 2 differ from the empty pockets 5 in that they are provided with undercuts 6 in order to secure the bearing needles, not shown, in the rolling-body pockets 2 from falling out and to guide them during operation. The undercuts 6 are dimensioned so that the bearing needles can be inserted with slight pressure in the rolling body pockets 2 and are then held against falling out. The roller bearing cage 1 is shown in a single row, but it can also be designed in two or more rows, if required by the structural conditions.

The illustrated embodiment shows a bearing cage 1, the rolling body pockets 2 and empty pockets 5 by means of milling in the rolling bearing cage 1 a worked. To produce the rolling body pockets 2, a cylindrical cutter 7 is moved radially against the roller bearing cage 1 until it has pierced the roller bearing cage 1, as shown, whereupon the cylindrical cutter 7 and / or the rolling bearing cage 1 are moved axially to a rolling body pocket 2 in the To cut to the required length.

In order to produce a blank pocket 5 with a different cross-section than the rolling body pockets 2, the cylindrical milling cutter 7 or the roller bearing cage 1 can be moved transversely to the longitudinal axis of the milling cutter 7 about the deflection 9 relative to the cage longitudinal axis 10, whereupon the empty pocket 5 in the same field as the aforementioned Wälzkörpertasche 2 is made by means of the same cylindrical cutter 7. Due to the deflection 9, the side walls or the center line 11 of the empty pocket 5 extend at an angle to the longitudinal axis of the cage 10, whereby a specific conveying or pumping action for lubricant in the rolling bearing is achieved.

To produce the undercuts 6, a form cutter 8 is radially guided into a prefabricated Wälzkörpertasche 2, as shown in Figure 1, then driven against a side wall of the Wälzkörpertasche 2 and then moved axially along this Wälzkörperwand along, whereby the first undercut 6 is formed. At the end of the pre-machined rolling body pocket 2, the shaping cutter 8 is moved axially in the circumferential direction in the direction of the opposite side wall of the rolling body pocket 2, whereby substantially straight end faces of the rolling body pocket 2 are incorporated. After reaching the second side wall of the rolling body pocket 2, the form milling cutter 8 or the roller bearing cage 1 is moved axially in the opposite direction until the opposite end of the rolling body pocket 2 is reached. As a final processing then the processing of the end surface, so that the apparent in Figures 1 and 2 form of Wälzkörpertaschen 2 is incorporated.

The illustrated embodiment shows only an incorporated empty pocket 5, but it is possible to incorporate more than one empty pocket 5 in the rolling bearing cage 1, a maximum of, for example, a rolling body pocket 2 alternately incorporate with undercuts 6 and a blank pocket 5 with oblique side walls in the rolling bearing cage 1.

In order to achieve a rational production of the rolling-body pockets 2 and the empty pockets 5, two parallel cylindrical cutters 7 and one form-cutters 8 can be arranged in the manner shown in a milling head, so that in each case a rolling-body pocket 2 is preprocessed by means of the cylindrical milling cutter 7, an empty pocket 5 finished machined and a pre-machined Wälzkörpertasche 2 finished by means of the form cutter 8.

Furthermore, it is also possible to form the cylindrical milling cutter 7 'and the form milling cutter so long that radially opposed rolling body pockets 2 can be milled out in one pass. If the roller bearing cage 1 is formed as a solid plastic cage, the rolling body pockets 2 and the empty pockets 5 can be formed in an injection mold by corresponding slide, which are substantially radially movable. In order to form the undercuts 6, however, the slides must be spreadable in the retracted position and be able to be extended for extension in the circumferential direction, so that they can be released from the undercuts 6 and pulled out. Such provided with numerous sliders injection molds are very expensive and costly to manufacture and therefore suitable only for mass production of such rolling bearing cages 1. The empty pockets 5, which are not needed for the rolling elements can, as shown in Figure 1, be incorporated with parallel and inclined at an angle to the cage longitudinal axis 10 side walls. It is also possible to produce the sidewalls of the rolling-element pockets radially apart or converging, thus to work them out conically or else spherically, asymmetrically or smaller or larger than the rolling bearing pockets 2. In the processing of the empty pockets 5 can simplify manufacturing take measures, in particular, the tool for editing the empty pockets 5 make it easier. Depending on the nature of this configuration, it is possible to have a targeted To produce conveying or pumping action or to set a throttling or obstructing effect for Schnniermittelfluss. These effects may be dependent on the rotational speed and the direction of rotation of the rolling bearing.

W

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LIST OF REFERENCE NUMBERS

1 rolling bearing cage

2 rolling body pocket

3 side ring

4 crossbar

5 empty bag

6 undercut

7, 7 'Cylindrical cutter

8 form cutters

9 desaxation

10 cage longitudinal axis

11 Centerline of a blank pocket

Claims

claims

Rolling bearing having a roller bearing cage (1) with a plurality of arranged in at least one row rolling elements pockets (2) for receiving at least one row of rolling elements, wherein the roller bearing cage (1) of two side rings (3) and a plurality of these connecting transverse webs (4 ), between which the rolling body pockets (2) are formed, and with at least one empty pocket (5), characterized in that the rolling bearing cage (1) is equipped in a row with fewer rolling elements, as it corresponds to the number of Wälzkörpertaschen (2) ,

Rolling bearing according to claim 1, characterized in that the at least one empty pocket (5) has a shape different from the rolling body pockets (2).

Rolling bearing according to claim 1 or 2, characterized in that the at least one empty pocket (5) is designed for receiving and / or distribution of lubricant.

Rolling bearing according to claim 2 or 3, characterized in that the at least one empty pocket (5) is shaped so that a conveying or pumping action is generated at least in one direction of rotation.

Rolling bearing according to one of Claims 1 to 4, characterized in that the center line (11) of the at least one empty pocket (5) forms an angle with a radius extending from the cage longitudinal axis (10).

Rolling bearing according to one of claims 1 to 5, characterized in that the transverse webs (4) and / or the side rings (3) in the region of the rolling body pockets (2) undercuts (6) for securing the rolling elements against falling out before assembly, and that the empty pockets (5) are formed without undercuts (6).

7. Rolling bearing according to one of claims 1 to 6, characterized in that the rolling body pockets (2) are designed to receive bearing needles.

A method for producing a roller bearing cage (1) according to any one of claims 1 to 7, characterized in that the rolling body pockets (2) by means of a cylindrical cutter (7) in a first step pre-processed and the empty pockets (5) by means of the same or another cylindrical milling cutter (7) ready to be incorporated.

A method according to claim 8, characterized in that at least the undercuts (6) in the region of the rolling body pockets (2) by means of a Formfräsers (8) are produced.

10. The method according to claim 9, characterized in that the Wälzkörpertaschen (2) by means of the cylindrical cutter (7) radially incorporated and the empty pockets (5) by means of the same or another cylindrical milling cutter (7) with a Desaxierung (9) are incorporated.