DE202012000854U1 - Rolling bearing cage and roller bearings - Google Patents

Abstract

Rolling bearing cage (1), comprising surfaces provided with a PTFE coating and surfaces that have no PTFE coating, the rolling bearing cage (1) further comprising at least one cage guide surface (6), the cage guide surface (6) having a first PTFE coating ( 7) is provided, characterized in that the roller bearing cage (1) has at least one second PTFE coating (8) which is directly adjacent to the first PTFE coating (7).

Description

Field of the invention

The invention relates to a roller bearing cage, comprising surfaces provided with a PTFE coating and surfaces which have no PTFE coating, the roller bearing cage further comprising at least one cage guide surface, wherein the cage guide surface is provided with a first PTFE coating. The invention further relates to a cage having such a bearing.

Such roller bearing cages can be guided via the cage guide surface either directly through a bearing ring by the bearing ring (eg., Outer ring or inner ring) for this purpose has a guide board. It is also conceivable that such rolling bearing cages are guided over a separate, sitting on a bearing ring ring. In any case, the cage guide surface is adapted to guide the rolling bearing cage by contact, i. H. to center and stabilize. Typically, the cage guide surface is a circumferential circumferential surface of a cage ring.

The contact on the cage guide surface provides in operation for friction between the roller bearing cage and the bearing ring and the rolling bearing cage and a seated on the bearing ring ring. This friction reduces the effectiveness of the rolling bearing, generates undesirable temperature increases in the rolling bearing and promotes wear of the bearing.

From the DE 695 34 033 T2 a bearing cage of a rolling bearing is known, which is either completely provided with a solid lubricant coating or in which purposefully and exclusively those surfaces are provided with a solid lubricant coating, which are in sliding contact with rolling elements or guide rings. Although reduces the bearing cage according to the DE 695 34 033 T2 the friction within the rolling bearing, however, is a complete lubricant coating consuming and expensive; Although a lubricant coating only surfaces in sliding contact with rolling elements or guide rings is easier and less expensive to manufacture, but leads to a reduced life of the coating.

Object of the invention

The invention has for its object to provide a generic rolling bearing cage, which can be easily and inexpensively manufactured and over a long period of a reduction of friction compared to uncoated rolling bearing cages allows.

Summary of the invention

This object is achieved by the features of the independent claim. Accordingly, a generic rolling bearing cage is characterized in that the rolling bearing cage has at least a second PTFE coating directly adjacent to the first PTFE coating by the rolling bearing cage is not completely coated, d. H. Having surfaces that have no PTFE coating, the rolling bearing cage can be easily and inexpensively manufactured.

The first PTFE coating on the cage guide surface serves the purpose of reducing friction between the rolling bearing cage and a bearing ring or separate ring.

The present invention is now based on the finding that the life of the first PTFE coating is not limited by a uniform wear of the entire surface of the coating. Rather, it was recognized that the first PTFE coating forms fraying at friction-affected edge areas or transitions to the uncoated surfaces. These frayings continue to spread throughout the entire first PTFE coating during operation and limit the life of the first PTFE coating.

According to the invention, at least one second PTFE coating should now protect the first PTFE coating from such wear. By having the at least one second PTFE coating directly adjacent to the first PTFE coating, a seamless transition is provided between these two coatings. Even in the still frictional edge regions of the first PTFE coating, there is therefore no transition between a coated surface and a non-coated surface according to the invention. The service life of the first PTFE coating could thus be significantly increased.

The first PTFE coating and the at least one second PTFE coating are preferably applied in one working step. In particular, the first PTFE coating and the at least one second PTFE coating have the same material properties and have an identical layer thickness.

Further advantages and features emerge from the dependent claims.

In order to achieve maximum friction reduction, it is provided according to an embodiment that the first PTFE coating completely covers the cage guide surface.

An optimum extension of the life of the first PTFE coating can be achieved if it is provided that the first PTFE coating is completely enclosed by the at least one second PTFE coating. All edges of the first PTFE coating thus merge seamlessly into the at least one second PTFE coating.

According to one embodiment, it is provided that the cage guide surface is formed by a lateral surface and that the second PTFE coating is applied to an end face adjoining the lateral surface. A lying between the lateral surface and the adjacent end edge is thus covered by the second PTFE coating. In particular, it may be provided that the second PTFE coating extends radially over 1 to 5 mm.

According to one embodiment, it is provided that the cage guide surface is formed by a lateral surface and that the second PTFE coating is applied to a lateral surface. It can be provided in particular that extends the second PTFE coating axially over 1 to 5 mm.

The roller bearing cage may have a body made of metal, preferably brass or steel. In principle, it is also conceivable to use a non-metallic body.

Brief description of the drawings

The invention will be described in more detail below with reference to the accompanying drawings. These show

1 a schematic representation of a first embodiment of the invention and

2 a schematic representation of a second embodiment of the invention.

Detailed description of the drawing

1 shows a schematic representation of a first embodiment of the invention as a three-dimensional representation.

Shown is a detail of a rolling bearing cage according to the invention 1 comprising one about an axis of rotation 5 encircling cage ring 2 with a plurality of axially projecting webs 3 , Between each two adjacent bars 3 becomes a bag 4 designed for a rolling element, not shown. The rolling bearing cage 1 is made in one piece from metal.

The rolling bearing cage 1 is a so-called inner ring bearing roller bearing cage 1 , ie on a radially inwardly directed lateral surface of the cage ring 2 is a cage guide surface 6 educated. The cage guide surface 6 extends circumferentially over the entire circumferential cage ring 2 and axially over the entire width of the cage ring 2 ,

The cage guide surface 6 is with a first PTFE coating 7 completely coated.

Directly adjacent to the first PTFE coating 7 has the rolling bearing cage 1 several second PTFE coatings 8th on. The second PTFE coatings 8th lie outside the cage guide surface 6 on surfaces that are directly attached to the cage guide surface 6 connect and are seamless with the first PTFE coating 7 connected.

Some of the second PTFE coatings 7 run radially on end faces of the cage ring 2 others of the second PTFE coatings 7 extend axially on surfaces of the webs 3 ,

2 shows a schematic representation of a second embodiment. Shown is an upper half of the axis of rotation 5 comprehensive axial section (a) of a rolling bearing or a detail, Z 'thereof (b).

The rolling bearing cage according to the invention 1 is in a spherical roller bearing 9 used and consists of two separately formed cage halves 10 . 11 , Every half of the cage 10 . 11 has a cage ring 2 with a plurality of axially projecting webs 3 on.

The two cage rings 2 contact a mid-board 12 an inner ring 13 over the cage guide surfaces 6 ,

First PTFE coatings 7 are on the cage guide surfaces 6 applied and second PTFE coatings 8th border directly on it.

Between the inner ring 13 and an outer ring 14 roll a variety of rolling elements 15 around the axis of rotation 5 from.

LIST OF REFERENCE NUMBERS

1

Rolling bearing cage

2

cage ring

3

web

4

bag

5

axis of rotation

6

Cage guide surface

7

first PTFE coating

8th

second PTFE coating

9

Spherical roller bearings

10

cage half

11

cage half

12

central rib

13

inner ring

14

outer ring

15

rolling elements

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 69534033 T2 [0004, 0004]

Claims (9)

Rolling bearing cage ( 1 ), comprising surfaces provided with a PTFE coating and surfaces which do not have a PTFE coating, the roller bearing cage ( 1 ) further comprising at least one cage guide surface ( 6 ), wherein the cage guide surface ( 6 ) with a first PTFE coating ( 7 ), characterized in that the rolling bearing cage ( 1 ) at least one second PTFE coating ( 8th ) directly to the first PTFE coating ( 7 ) adjoins. Rolling bearing cage ( 1 ) according to claim 1, characterized in that the first PTFE coating ( 7 ) the cage guide surface ( 6 ) completely covers. Rolling bearing cage ( 1 ) according to claim 1 or 2, characterized in that the first PTFE coating ( 6 ) by the at least one second PTFE coating ( 8th ) is completely bordered. Rolling bearing cage ( 1 ) according to one of the preceding claims, characterized in that the cage guide surface ( 6 ) is formed by a lateral surface and that the second PTFE coating ( 8th ) is applied to a front side adjacent to the lateral surface. Rolling bearing cage ( 1 ) according to claim 4, characterized in that the second PTFE coating ( 8th ) extends radially over 1 to 5 mm. Rolling bearing cage ( 1 ) according to one of the preceding claims, characterized in that the cage guide surface ( 6 ) is formed by a lateral surface and that the second PTFE coating ( 8th ) is applied on a lateral surface. Rolling bearing cage ( 1 ) according to claim 6, characterized in that the second PTFE coating ( 8th ) extends axially over 1 to 5 mm. Rolling bearing cage ( 1 ) according to one of the preceding claims, characterized in that the roller bearing cage ( 1 ) has a body made of metal, preferably made of brass or steel. Rolling bearing, comprising a roller bearing cage ( 1 ) according to any one of the preceding claims.

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