DE102015224046A1 - roller bearing - Google Patents

Abstract

Rolling bearing (1) comprising an outer ring (2) and an inner ring (3) and a roller bearing cage (5) and a plurality of Wälzlagerkäfig (5) supported rolling elements (4), wherein the rolling bearing cage (5) consists of a metallic material and sections or completely covered with a polymeric coating (7).

Description

The invention relates to a rolling bearing comprising an outer ring and an inner ring and a roller bearing cage and a plurality of rolling elements supported by the rolling bearing cage.

Rolling bearings in the area of large bearings usually comprise segmented roller bearing cages, with partially multi-row roller bearings are used with segmented roller bearing cages.

On the one hand, the rolling bearing cage holds the rolling elements separated from each other to prevent them from touching each other. On the other hand, the rolling elements are usually guided by the rolling bearing cage at an equal distance from each other, resulting in a uniform load distribution of the bearing. In the case of collapsible or swing-out bearings, the roller bearing cage holds the rolling elements together, thereby facilitating the installation of the bearings.

Usually, a rolling bearing comprises two bearing rings, between which the rolling elements move. The rolling elements are usually balls, cylindrical rollers, needle rollers, tapered rollers or barrel rollers. In the case of needle roller bearings or on-board spherical roller bearings, the roller bearing cage additionally ensures the correct position of the roller body axes.

Out DE 10 2012 101 651 A1 is known an axial-radial roller bearing and a method for producing a roller bearing cage for an axial-radial roller bearing. Here, a ring or a ring segment made of a solid metal material is provided and formed by a forming process to form an annular or segmented round body of the rolling bearing cage.

Out DE 10 2012 101 649 A1 For example, there is known a method of manufacturing a rolling bearing cage and an apparatus for carrying out the method, wherein a steel strip having openings is provided for each one rolling element and bent into a ring before a continuous coating is applied.

Usually occur in rolling bearings in the large storage area on large radial and axial loads. Conventional rolling bearing cages have poor emergency running properties with a possible lack of lubrication or even lack of lubrication, which leads in most cases in the short term to a complete malfunction of the entire bearing.

The invention is therefore based on the problem of specifying a rolling bearing with an improved rolling bearing cage.

To solve this problem is provided according to the invention in a rolling bearing of the type mentioned that the rolling bearing cage consists of a metallic material and is partially or completely covered with a polymeric coating.

This makes it possible within the scope of the invention that a cost reduction is achieved by the use of a body made of a metallic material of a roller bearing cage, wherein the base body is technically upgraded by application of the polymeric coating, thereby characterized both the mechanical and tribological properties the rolling bearing cage can be specifically improved. For example, by the polymeric coating of the roller bearing cage, a lower friction and thus a lower wear can be achieved, wherein the polymeric coating can be selected depending on a plurality of target variables.

In addition, the polymeric coating according to the invention is advantageous because the rolling bearing cage can be susceptible to corrosion and is protected by the polymeric coating from the ambient conditions.

The polymeric coating can be applied, for example, by depositing thin layers of a polymer solution. However, it is also possible to spray on polymer emulsions or spray-on by the flame spraying method, with subsequent sintering or annealing under heat. Moreover, it is also within the scope of the invention that the coating is applied by powder coating. For example, it may be applied to a polymeric powder by spraying or in a fluidized bed on a hot or electrostatically charged substrate. A section-wise coating can in principle be applied by appropriate masking methods.

For example, an inventive roller bearing cage on the outer bearing ring outboard, be led inboard on the bearing inner ring or guided by the rolling body itself. In this regard, in the context of the invention, only a portion of polymeric coating, which is applied only to particularly functional relevant points of the rolling bearing cage possible to save material costs. Thus, it is within the scope of the invention that in a rolling bearing cage, a polymeric coating, for example, is mounted exclusively in the area of the cage guide.

In addition, the rolling bearing cage may be a segmented roller bearing cage having individual openings which serve to receive and support each of a rolling element. In a rolling bearing with a segmented roller bearing cage, which is guided by the rolling elements themselves, for example, the polymeric coating can be applied exclusively to the inner sides of the individual segments of the rolling bearing cage.

In a rolling bearing cage according to the invention can be used in principle sheet metal cages and solid cages, which in turn may consist of various metallic materials, preferably of brass or steel.

The rolling bearing cage can consist of both stainless and non-stainless steel. For example, the rolling bearing cage can be made of chrome steel, with chromium steel combining good mechanical properties with good corrosion resistance.

Specific grades of steel which are suitable for the production of the invention may also be alloyed for better hardenability. For example, manganese (Mn) or molybdenum (Mo) can be used for the alloy.

It is also within the scope of the invention that the polymeric coating is completely applied and has different layer thicknesses.

The rolling bearing cage can be coated over the entire surface and thus be completely protected from direct contact with a bearing ring or the rolling elements, wherein the polymeric coating may have, for example, at the most functionally relevant points a different layer thickness of the full-surface coating. According to the invention, the layer thickness at these function-relevant points is thicker than at the remaining points of the rolling bearing body. This results in a particularly advantageous wear protection, especially at the points where the rolling bearing cage with the rolling elements or the bearing rings is possibly in contact.

For example, the coating on the inner sides of individual segments of the roller bearing cage and / or in the region of the rolling bearing guides have a greater layer thickness, than at all other points of the rolling bearing cage.

In the rolling bearing according to the invention, it may be provided that the polymeric coating is a polyadduct, a chain polymer or a polycondensate, in particular of dicarboxylic acids, diamines and / or lactams.

Basically, the use of thermoplastic or thermosetting plastics is possible, preferably PA6, PA66, PA11, PA12 or a material of the material group polyaryletherketones (PAEK), polyarylethersulfone (PES), polyphenylene sulfide (PPS), polyetherimide (PEI), polyimides (PI) or Polyamide-imide (PAI) is possible.

These materials can be used either exclusively or in a mixture with at least one other material. If a mixture of at least two different plastic materials is used, the material properties can be specifically influenced in order to adapt them to the technical requirements which the rolling bearing cage according to the invention has to fulfill.

A variant of the invention can provide that the coating contains additives, in particular in a proportion of 10 to 40 percent by weight.

An inventive plastic material containing additives z. B. in powder or particulate form or in the form of fibers, causes a rolling bearing cage according to the invention is particularly efficient and inexpensive to produce, at the same time its life is extended by the improved material properties.

Thus, within the scope of the invention, for example, fiber-reinforced plastics can serve as a coating for the roller bearing cage, whereby these can be enriched with suitable further additives or solid lubricants in order to improve the friction coefficients and the wear resistance of these layers.

As a result, a polymeric coating staggered with selected additives protects the rolling bearing cage, e.g. if there is insufficient lubricant, as is the case with a lubricant break-off. A targeted and provided with additives polymeric coating thus leads to improved runflat property and ensures that the functionality of the bearing is maintained.

An additive may consist of graphite, polytetrafluoroethylene (PTFE), aramid fibers, aramid powder, mineral microfibers or carbon fibers, although this list is not exhaustive.

Within the scope of the invention, at least two different types of fibers can also be used in order to use them with the plastic material of the polymeric coating as a matrix to form a fiber composite material for a coating material. For example, a combination of aramid fibers and carbon fibers is possible.

The invention will be explained below with reference to an embodiment with reference to the drawings. The drawings are schematized representations and show:

1 a schematic view of a rolling bearing according to the invention in a partial view; and

2 a schematic view of a rolling bearing cage of a rolling bearing according to the invention, in a partial view.

1 shows a schematic representation of a sectional partial view of a rolling bearing 1 , which is designed as a single row cylindrical roller bearing. The rolling bearing 1 comprises two spaced-apart bearing rings, wherein a bearing ring is an outer ring 2 and a bearing ring an inner ring 3 is. Between the two bearing rings are designed as cylindrical rollers rolling elements 4 arranged.

The rolling elements 4 be from a rolling bearing cage 5 supported. The rolling bearing cage 5 is segmented and is defined by the rolling elements 4 self-guided. All segments of the rolling bearing cage 5 are the same size, causing the rolling elements 4 all are held at the same distance from each other.

In other embodiments, the rolling elements 4 Also be designed as balls, tapered rollers, needles or spherical rollers. The rolling bearing cage 5 holds the rolling elements 4 separated from each other and thus prevents mutual contact of the rolling elements 4 , The rolling bearing cage 5 is segmented and is defined by the rolling elements 4 self-guided.

In the 2 shown sectional view of the rolling bearing cage 5 shows this without salaried rolling elements 4 , At the main body of the roller bearing cage 6 it is a massive cage made of a metallic material.

In addition, in the illustrated embodiment, one on the main body of the roller bearing cage 6 completely applied polymeric coating 7 shown. This polymeric coating 7 represents z. B. a functionality of the bearing in a lubricant breakage safe. In the embodiment shown, the polymeric coating is 7 with a uniform layer thickness on the entire main body of the rolling bearing 6 applied. It is conceivable to increase the layer thickness locally in areas which are stressed particularly mechanically during operation, ie to produce locally different layer thicknesses.

Preferably, but not necessarily, the polymeric coating of a thermosetting or thermosetting material contains one or more additives, the z. B. positively influence the mechanical properties of the coating, such. As fibers, such as aramid fibers or carbon fibers, or powder or particulate additives, eg. As graphite or PTFE, in order to design the tribological properties of the coating according to the desired or given requirements targeted.

LIST OF REFERENCE NUMBERS

1

 roller bearing

2

 outer ring

3

 inner ring

4

 rolling elements

5

 Rolling bearing cage

6

 Main body of the rolling bearing cage

7

 Polymeric coating

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 102012101651 A1 [0005]
• DE 102012101649 A1 [0006]

Claims (4)

Roller bearing ( 1 ) comprising an outer ring ( 2 ) and an inner ring ( 3 ) and a rolling bearing cage ( 5 ) and several through the rolling bearing cage ( 5 ) supported rolling elements ( 4 ), characterized in that the rolling bearing cage ( 5 ) consists of a metallic material and partially or completely with a polymeric coating ( 7 ) is occupied. Rolling bearing according to claim 1, characterized in that the polymeric coating ( 7 ) is completely applied and has different layer thicknesses. Bearing according to claim 1 or 2, characterized in that the polymeric coating ( 7 ) is a polyadduct, a chain polymer or a polycondensate, in particular of dicarboxylic acids, diamines and / or lactams. Rolling bearing according to one of the preceding claims, characterized in that the polymeric coating ( 7 ) Contains additives, in particular in a proportion of 10 to 40 weight percent.

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