DE102016120612A1 - Axial rolling bearing cage and axial rolling bearing - Google Patents

Abstract

An axial rolling bearing cage (1) with rolling body pockets (2) for spherical rolling bodies (7) is characterized in that the dimension of all rolling body pockets (2) in the radial direction is greater than in the circumferential direction of the Axialwälzlager cage. Such Axialwälzlager cage (1) is preferably used in an axial roller bearing (3) with races (8, 9) and an Axialwälzlager cage (1) for rolling elements (7), in which the races (8, 9) on the one hand and the Axialwälzkörper cage (1) on the other hand have different coefficients of expansion.

Description

The invention relates to an axial rolling bearing cage according to the preamble of claim 1 and an axial rolling bearing according to the preamble of claim 9.

Axial rolling bearing cages are used in axial rolling bearings to hold rolling elements in a circular path during the bearing movement. In general, similar rolling elements are used within a rolling bearing, and provided in the rolling bearing cage rolling elements pockets are uniform in shape.

From the DE 10 2014 209 236 A1 Axial roller bearing cages are known for cylindrical rolling elements, in which the rolling bearing pockets are provided with different dimensions in the radial direction. A first group having a first extent in the radial direction is provided for a first type of rolling elements, while a second type of rolling body pockets is provided with a shorter extent in the radial direction for correspondingly shorter rolling elements. For different load scenarios, such a roller bearing cage can be equipped with only the first type of rolling elements, only with the second type of rolling elements or with both Wälzkörperarten. The rolling elements are each adapted in the known manner to the expansions of the rolling body pockets.

For a radial ball bearing is from the DE 10 2010 047 962 A1 a ball bearing cage is known in which the ball pockets seen in the circumferential direction, ie in the running direction, a dimension which is larger by 20% to 55% than the diameter of the ball therein. As a result, long-hole ball pockets are provided with the longer dimension in the circumferential direction, which is intended to increase the wear resistance. The balls should be given a greater opportunity in the ball pockets in the circumferential direction to compensate for the different ball speeds by changing the position, without generating additional forces in the circumferential direction on the ball bearing cage.

From the US 2014/019311 A1 For a radial ball bearing a cage is known in which the ball pockets have different dimensions. Thus, in one embodiment, one of the ball pockets is provided as a guide pocket and made circular, while the other ball pockets are formed in the circumferential direction as slots. It is a restless run and the advent of vibrations to be avoided. This prior art also discloses variants with other different bag shapes, z. B. in elliptical shape, approximate rectangular shape or the like. It also slots are revealed with their longitudinal extent in the axial direction.

The cage shapes presented in the aforementioned publications on the prior art should in particular be advantageous for smooth running or serve for adaptation to different load types. Not addressed are possible problems with differences in the material of the races on the one hand and the cage on the other hand, if this material difference brings different coefficients of expansion. Temperature changes can lead to disturbances in the course of the rolling elements.

It is an object of the present invention to provide a cage for an axial roller bearing and an axial rolling bearing with an alternative form of rolling bearing pockets with advantageous running properties for the bearing.

This object is achieved with a Axialwälzlager cage of the type mentioned above with the characterizing features of claim 1 and in an axial roller bearing of the type mentioned above with the characterizing feature of claim 9.

Advantageous exemplary embodiments emerge in particular from the dependent claims.

Thus, it is proposed that for the Axialwälzlager cage the dimensions of all Wälzkörpertaschen for spherical rolling elements in the radial direction are greater than in the circumferential direction of the Axialwälzlager cage.

It may be advantageous to design the axial rolling bearing cage according to the invention such that the dimensions of the rolling body pockets in the radial direction exceed the dimensions of the associated rolling body by at least 10%. The axial roller bearing cage according to the invention can also be designed such that the dimensions of the rolling body pockets in the radial direction exceed the dimensions of the associated roller body by at least 30%. Thus, in an exemplary embodiment, the extent of a rolling element pocket in the radial direction may be about 4.8 mm while the ball diameter is 4 mm. In this case, the rolling body pocket can be composed of two partial spherical shells, which have a radius of 2.1 mm and the ball centers are separated from each other in the radial direction by a linear distance of 0.6 mm. In a direction perpendicular to the axial direction, passing through the ball centers radial plane the Wälzkörpertasche is limited at its two ends in each case by two semicircles, in the above example, also in Radial direction with 0.6 mm from each other. Between the part spherical shells, the boundary can be straight. Further remaining in this example, the radially-dimensioned dimension of the rolling-element pocket exceeds the diameter of the spherical rolling element by 20%.

It may be advantageous if the axial rolling bearing cage according to the invention has three sections. These three sections include a radially inner inner portion and a radially outer outer portion. These two sections are each annular. The inner portion and the outer portions are interconnected by a middle portion. This middle section has an oblique course to a radial plane perpendicular to the axial direction, e.g. with a conical-ring-shaped central surface at a constant angle to the radial plane, so that the inner portion is arranged offset axially relative to the outer portion. It can e.g. the conical-ring-shaped central surface and / or an upper and / or a lower boundary surface of the central portion to the axial direction have an acute angle between 20 ° and 50 °. The cone ring shape is based on a straight circular cone.

Such a form of Axialwälzlager- cage is advantageous in an axial rolling bearing, in which the Axialwälzlager cage has a different thermal expansion than the races of Axialwälzlagers. If the axial roller bearing is subjected to a high temperature fluctuation, a different thermal expansion of the cage relative to the rings of the bearing can cause the radially inner edge of the cage pocket or the outer edge of the cage pocket to touch the rolling elements in an undesired manner. Is z. As the coefficient of expansion of the cage is higher than that of the ring, the cage grows at a temperature increase relative to the races, and the radially inner boundaries of the Wälzkörpertaschen move in the radial direction to the respective rolling elements. It would also be conceivable to use such a cage with such designed rolling bearing pockets in cryogenic applications. In this case, the cage shrinks in relation to the races higher coefficient of expansion, which move when cooled, the radially outer boundaries of the rolling elements in the direction of the respective rolling elements. Depending on the choice of material for the races and the Axialwälzlager-cage, it may also be advantageous if the dimension of the rolling body pocket exceeds the dimension of the associated rolling element by at least 10%, more preferably by at least 30%.

In the circumferential direction, the clearance between the rolling element and the rolling-element pocket is preferably at most 15% of the extent of the rolling-element pocket in the circumferential direction.

The term dimension of the rolling body pocket and the rolling element respectively refers to a cross-section perpendicular to the axial direction.

The axial roller bearing cage according to the invention may have rolling-element pockets in different shapes within the cross-section perpendicular to the axial direction, in particular an oval or an ellipse, a rectangle, e.g. B. with rounded corners, two semicircles with an intermediate straight course or variants of the aforementioned forms. The centers of the two semicircles are radially spaced. It is crucial that the rolling body pocket seen in the radial direction relative to the rolling body has a greater clearance than seen in the direction of travel.

The Axialwälzlagerkäfig invention may be integrally formed.

In an axial roller bearing according to the invention with an axial roller bearing cage according to the invention, in the case of rolling balls as rolling elements, the contact angle for rolling balls is at least 10 ° and at most 30 °.

A preferred embodiment of the invention Axialwälzlager-cage and the Axialwälzlagers are shown below with reference to figures.

• 1: einen Axialkugellager-Käfig für ein Axialschrägkugellager in perspektivischer Ansicht,
• 2: in Aufsicht einen Ausschnitt des Axialkugellager-Käfigs gemäß 1,
• 3: den Axialkugellager-Käfig ausschnittsweise im Querschnitt und
• 4: ausschnittsweise im Querschnitt ein Axialschrägkugellager mit einem Axialkugellager-Käfig gemäß den 1 bis 3.

It shows

• 1 : An axial ball bearing cage for a thrust angular contact ball bearing in perspective view,
• 2 in supervision a section of the thrust ball cage according to 1 .
• 3 : The axial ball bearing cage in sections in cross section and
• 4 : Sectionally in cross-section an angular contact thrust ball bearing with an axial ball bearing cage according to the 1 to 3 ,

1 shows in perspective view an axial ball bearing Kä 1 with a variety of bullet pockets 2 , Since the axial ball bearing Kä 1 for an axial angular contact ball bearing 3 (please refer 4 ) is provided, the axial ball bearing Ka 1 a ramp-shaped middle section 4 on, the given to an axial displacement of a radially outer outer portion 5 relative to a radially inner inner portion 6 (please refer 3 ) leads.

4 shows the axial ball bearing Kä 1 installed in an axial angular contact ball bearing 3 along with a ball 7 , The pressure angle β is 15 °, but may have other values, preferably at least 10 ° and at most 30 °.

The bullet pockets 2 have a slot shape with the longitudinal extent in the radial direction, ie perpendicular to the direction of the balls 7 , In the in the 1 to 4 The example shown is the shape of the ball bag 2 in a cross section parallel to the plane of the 2 seen from two radially spaced semicircles and a straight intermediate piece together. As shown in the introduction, the ball bag 2 but also accept other forms and z. B. elliptical or rectangular, z. B. with rounded corners, be formed.

4 illustrates a situation where between the ball 7 , which are on the raceways of the two races 8th and 9 of the angular thrust ball bearing 3 is arranged, and the inner section 6 a much greater freedom 10 exists as between the ball 7 and the outer section 5 , The axial ball bearing Kä 1 is made of a different material than the races 8th and 9 , which preferably consist of metal. The axial ball bearing Kä 1 consists of a high-performance plastic, z. Example of a polyamide (PA) or polyamide-imide (PAI), polyetherimide (PEI), polyetheretherketone (PEEK), polyetherketone (PEK). So go different coefficients of expansion for the Axialkugellager Kä 1 on the one hand and the races 8th and 9 on the other hand. In the in 4 shown situation may be at a temperature increase and a higher expansion coefficient of the thrust ball cage 1 opposite the races 8th and 9 the axial ball bearing Kä 1 in the radial direction relative to the races 8th and 9 expand more without leaving the inner space 10 completely disappears and thereby the inner section 6 the ball 7 touched and deteriorated running characteristics of the thrust ball thrust bearing 3 would lead.

In 3 the thrust roller cage is shown which consists of three sections. These three sections consist of a radially inner section 6 and a radially outer portion 5 , These two sections are each annular. The two sections are from a middle section 4 obliquely connected. Thus, the radially inner portion 6 relative to the radially outer portion 5 arranged offset axially. The intermediate section 4 connects the radially inner section 6 and a radially outer portion 5 at an acute angle α between 20 ° and 50 ° relative to the axis of rotation.

Cryogenic applications would also be possible with a cage designed according to the invention. However, an embodiment suitable for this purpose is not shown in the figures. For cryo applications would have due to the different expansion coefficients of the thrust ball cage 1 opposite the races 8th and 9 the axial ball bearing Kä 1 in the radial direction relative to the races 8th and 9 contract more strongly, without thereby the radially outer portion 5 the ball 7 touched and deteriorated running characteristics of the thrust ball thrust bearing 3 would lead to operation below normal temperature. In this case, the clearance from the ball would have to 7 to the radially outer portion 5 greater than the distance between rolling elements 7 and the radially inner portion 6 ,

The position of the ball 7 relative to the axial ball bearing Kä 1 in the radial direction is when assembling the axial angular contact ball bearing 3 chosen so that at the expected temperature ranges in which the thrust ball thrust bearing 3 should exercise its function, it does not cause a collision between the axial ball bearing Kä due to the different expansion coefficients 1 and the balls 7 comes in the radial direction.

LIST OF REFERENCE NUMBERS

1

Axial ball cage

2

ball pocket

3

axial angular

4

middle section

5

outer section

6

inner section

7

Bullet

8th

race

9

race

10

free space

α

angle

β

contact angle

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014209236 A1 [0003]
• DE 102010047962 A1 [0004]
• US 2014019311 A1 [0005]

Claims (12)

Axial roller bearing cage with Wälzkörpertaschen (2) for spherical rolling elements (7), characterized in that the dimension of all Wälzkörpertaschen (2) in the radial direction is greater than in the circumferential direction of the Axialwälzlager cage. Axial rolling cage after Claim 1 , characterized in that in the radial direction, the dimension of all Wälzkörpertaschen (2) exceeds the dimension of the associated rolling element (7) by at least 10%. Axial rolling cage after Claim 2 , characterized in that in the radial direction, the dimension of all Wälzkörpertaschen (2) exceeds the dimension of the associated rolling element (7) by at least 30%. Axial roller bearing cage according to one of the preceding claims, characterized in that all the rolling body pockets (2) are elongated holes with their longitudinal extent in the radial direction. Axial rolling bearing cage according to one of the preceding claims, characterized in that at least one of the rolling body pockets (2) has two partial spherical shells whose centers are radially spaced. Axial rolling bearing cage according to one of the preceding claims, characterized in that the Axialwälzlager cage has three, concentric in plan view in the axial direction to the axis of rotation, successive in the radial direction annular portions, namely an inner portion (6), a central portion (4). and an outer portion (5), wherein the middle portion (4) extends obliquely to a radial plane perpendicular to the axial direction, that the inner portion (6) and the outer portion (5) are axially offset from each other. Axial rolling cage after Claim 6 , characterized in that the central portion (4) with an upper boundary surface and / or a lower boundary surface or a central surface at an acute angle α of at least 20 ° and at most 50 ° relative to the axis of rotation. Axial roller bearing cage according to one of the preceding claims, characterized in that the Axialwälzkörper cage (1) consists at least predominantly of plastic. Axial rolling bearing with races (8, 9) and a Axialwälzlager-cage (1) for rolling elements (7), wherein the races (8, 9) on the one hand and the Axialwälzlager cage (1) on the other hand have different coefficients of expansion, characterized in that the Axialwälzlager -Cage (1) an axial rolling cage (1) according to one of Claims 1 to 8th is. Axial rolling bearing after Claim 9 , characterized in that it is an axial ball bearing. Axial rolling bearing after Claim 10 , characterized in that it is an axial angular contact ball bearing (3). Axial rolling bearing after Claim 11 , characterized in that the pressure angle β of the rolling balls (7) is at least 10 ° and at most 30 °.

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