DE102015201174A1 - Coated bearing and process for its production - Google Patents

Abstract

Bearing (1), comprising a first bearing part (2) with a first base body (3) and a first running surface (4) and a second bearing part (5) with a second base body (6) and a second running surface (7), wherein the first running surface (4) and the second running surface (7) are at least partially facing each other. At least the first, running surface (4) has at least partially a lipophilic coating (8).

Description

The invention relates to a coated bearing, in particular a rolling bearing, a linear guide and a ball screw, comprising a first bearing part with a first base body and a first tread and a second bearing part with a second base body and a second tread, wherein the first tread and the second tread at least partially facing each other. Furthermore, the invention relates to a method for its production.

Radial and axial bearings are used for the rotatable mounting of two objects to each other. Rolling bearings have two bearing rings, which can be arranged on each one of the objects to be stored and rotatable relative to each other about a common axis. In order to enable as frictionless sliding of the bearing rings together as possible, rolling elements are arranged between the bearing rings, which roll or roll on running surfaces of the bearing rings. Linear guides or ball screws operate essentially according to the same principle, whereby in linear guides a slide of a guide rail and in the case of ball screws a nut slides on a spindle.

To reduce the rolling resistance of rolling bearings, linear guides or ball screws, to ensure a quiet and smooth running, to reduce operating temperatures and to achieve low wear, the rolling elements and the treads have a smooth and uniform surface and are made of a hard, low-wear , preferably made of corrosion-resistant material. Furthermore, rolling bearings, linear guides and ball screws have lubrication, e.g. grease or oil lubrication to further reduce rolling resistance.

In operation, different zones of the rolling bearings, linear guides or ball screws are exposed to different loads that cause a different wear. Thus, high punctual pressure forces in rolling bearings, linear guides or ball screws initially lead to a local displacement of the lubricant. Centrifugal forces also assist in displacing the lubricant in the direction of the bearing seals. In the absence of relubrication, this can lead to a local dry running of the bearing, so that at some points of the bearing no longer sufficient lubricant is present to ensure adequate or continuous lubrication of the bearing. In order to ensure operational safety of such a bearing supply of the bearing within a certain lubrication relubrication cycle is required.

A lack of lubricant leads to an increased operating temperature of the bearing and results in increased wear or surface fatigue.

The object of the present invention is therefore to provide a bearing and a method for producing a bearing, which ensures a sufficient supply of lubricant in the contact zone. In particular, it is the object of the present invention to provide a bearing which has an improved distribution of lubricant and a lower wear, a longer life and a longer relubrication cycle than conventional bearings even under high mechanical load.

This object is achieved by a bearing according to claim 1. The dependent claims 2 to 9 relate to particularly preferred embodiments of a generic bearing. Furthermore, the object is achieved by a method for producing a bearing according to claim 10.

Accordingly, the object of the present invention is achieved by a bearing, comprising a first bearing part with a first base body and a first tread and a second bearing part with a second base body and a second tread, wherein the first tread and the second tread are at least partially facing each other , In this case, the first tread at least partially on a lipophilic coating.

The first bearing part and the second bearing part are movable relative to each other, e.g. rotatable about a common axis or movable along a longitudinal axis. Preferably, the first tread and the second tread are designed to reduce a friction occurring in such relative movement and accordingly have e.g. a low roughness value and / or are designed to be particularly hard or erosion resistant.

The first tread has at least partially a lipophilic coating. A lipophilic coating has the special property of attracting greases or lubricants. Such a layer is particularly advantageous in areas of the bearing in which particularly high mechanical forces act during operation of the bearing, so that at least in these areas, even after prolonged operation of the bearing still sufficient lubricant is present. Therefore, it is particularly advantageous if at least one central region of the first running surface has a lipophilic coating. Alternatively, the complete first tread has a lipophilic coating.

Such a bearing has the advantage over conventional bearings that with prolonged use of the bearing, if already a part of the lubricant of the bearing is aged or displaced, at least in areas where a lipophilic coating is arranged, an adequate supply of lubricant is ensured , As a result, a lower friction value of the bearing and a lower heat generation during operation is ensured. Thus, the bearing has an increased life and a prolonged Naschschmierzyklus.

According to a preferred embodiment of the method, the first running surface has a lipophobic coating, wherein the lipophilic coating is arranged substantially between the first base body and the lipophobic coating.

A lipophobic coating has the special property of repelling fats or lubricants. In this case, a lipophobic coating can be arranged on the complete lipophilic coating. This has the advantage that in a non-worn bearing the lubricant gets in contact only with the lipophobic coating and repelled, with continuing wear occurs. Wear removes the lipophobic coating locally, thereby exposing the lipophilic coating at these locations and attracting lubricant. In this way it is ensured that in particularly heavily mechanically stressed areas of the bearing more lubricant is arranged than in less stressed areas. This has the advantage that even with little existing lubricant sufficient lubrication in these areas is guaranteed. In an alternative embodiment, the lipophobic coating is only in areas of the bearing, e.g. in marginal areas, which are exposed to relatively low mechanical loads or over which the lubricant could escape from the camp. This has the advantage that the lubricant is concentrated in particular on areas which are exposed to an increased load and that escape of the lubricant from the bearing is at least partially prevented. Such bearings have lower internal friction values, increased service life and a prolonged Nachschmierzyklus even after prolonged operation.

Preferably, the second tread has a lipophilic coating and a lipophobic coating, wherein the lipophilic coating is disposed substantially between the second body and the lipophobic coating. This has the advantage that both on the first running surface and on the second running surface a lipophilic coating is arranged, which favors an optimum distribution of the lubricant in the bearing. Such a bearing has lower internal friction values, increased service life and a prolonged Nachschmierzyklus even after prolonged operation.

More preferably, the bearing is designed as a rolling bearing, wherein the first bearing part is designed as an inner ring or outer ring and the second bearing part accordingly as an outer ring or inner ring. At least one rolling element is arranged between the first running surface and the second running surface. Preferably, the rolling bearing has a plurality of rolling elements in order to better distribute forces acting between inner ring and outer ring on the running surfaces or the coatings of the running surfaces. Alternatively, the bearing is designed as a linear guide or ball screw.

In an advantageous embodiment of the rolling elements is arranged in a Wälzkörperkäfig. Such Wälzkörperkäfig has the advantage that adjacent rolling elements always have a sufficient distance from each other and not rolling in operation. As a result, the internal friction and thus the wear of the bearing is reduced and extends the life.

Preferably, the bearing is designed as a rolling bearing. Such bearings have in some areas a particularly high load, so that a supply of lubricant can be advantageously improved by such a coating in these areas.

It is preferred that the lipophobic coating has at least one inner recess in which a first part of the lipophilic coating is arranged, the first part of the lipophilic coating being surrounded on at least two sides by the lipophobic coating. In a preferred embodiment, the lipophilic coating has a T-shaped cross-section. Also preferably, the lipophobic coating is formed such that in one area the lipophilic coating is not covered by the lipophobic coating. Thus, e.g. a region of the lipophilic coating of the first bearing part facing the second bearing part directly, without a lipophobic coating is disposed in this area between the lipophilic coating and the second bearing part. This has the advantage that a better supply of lubricant is already ensured in the case of a bearing which is not or only slightly worn in this area of the lipophilic coating. An abrasion of the lipophobic coating is therefore not necessary because the lipophilic coating is already exposed.

It is particularly preferred that in a first area, in which the operation of the camp the greatest forces occur, a layer thickness of the lipophilic coating is thicker than in other areas and / or a layer thickness of the lipophobic coating is thinner than in other areas. This has the advantage of ensuring the presence of a lipophilic coating in the first area and thus the positive properties of the lipophilic coating in the first area. A thinner lipophobic coating in the first region has the advantage that only little wear of the lipophobic coating is required until the beneficial properties of the lipophilic coating in the first region are felt.

Particularly advantageously, a lubricant is arranged between the first bearing part and the second bearing part, which has at least one AW and / or EP additive. AW additives (antiwear) are additives for a lubricant that reduce abrasive wear. Extreme-pressure (EP) additives are additives for a lubricant that prevent welding of pressure bearing metallic bearing parts.

• – Bereitstellen eines ersten Lagerteils mit einem ersten Grundkörper und einer ersten Lauffläche;
• – Auftragen einer lipophilen Beschichtung auf die erste Lauffläche;
• – Auftragen einer lipophoben Beschichtung auf der lipophilen Beschichtung;
• – Bereitstellen eines zweiten Lagerteils mit einem zweiten Grundkörper und einer zweiten Lauffläche; und
• – Anordnen mindestens eines Wälzkörpers zwischen der lipophoben Beschichtung und der zweiten Lauffläche.

Moreover, the object is achieved by a method for producing a bearing with the steps:

• - Providing a first bearing part with a first base body and a first tread;
• - Applying a lipophilic coating on the first tread;
• Applying a lipophobic coating to the lipophilic coating;
• - Providing a second bearing part with a second base body and a second tread; and
• - Arranging at least one rolling element between the lipophobic coating and the second tread.

With this method, a bearing according to the invention can be produced.

In the following the invention will be explained in more detail with reference to a drawing. In the drawings shows schematically:

1 a flow diagram of the inventive method for producing a bearing;

2 a plan view of a bearing ring of a first embodiment of a bearing;

3 a sectional plan view of the bearing ring 2

4 a side view of the first embodiment of the bearing with the bearing ring 2 , and

5 a sectional plan view of a bearing ring of a second embodiment of a bearing.

In 1 is shown in a flow chart, a method for producing a rolling element cage. In the first process step 100 becomes a first bearing part 2 with a first body - and a first tread 4 provided. In the second process step 200 becomes the first tread 4 with a lipophilic coating 8th coated. Here is the lipophilic coating 8th preferably at least in areas of the first tread 4 arranged in the operation of the warehouse 1 are exposed to particularly high mechanical loads. In the third process step 300 becomes a lipophobic coating 9 on the lipophilic coating 8th applied. Preferably, the lipophobic coating covers 9 at least areas of the lipophilic coating 8th in the operation of the warehouse 1 less exposed to mechanical stress. In the fourth method step, a second bearing part 5 with a second main body 6 and a second tread 7 which also has a lipophilic coating 8th , preferably with a lipophobic coating 9 is covered. In the fifth process step 500 will be at least one rolling element 12 between the lipophobic coating 9 and the second tread 7 arranged. The thickness of the lipophilic coating 8th and the lipophobic coating 9 is in relation to the inner ring 10 preferably substantially thinner than shown in the drawing.

2 shows a plan view of a bearing ring of a first embodiment of a bearing 1 , The bearing ring is a first bearing part 2 and is as an inner ring 10 formed with a bearing axis L. The inner ring 10 has a tread 4 on, on two outer sides in each case a lipophobic coating 9 and between the lipophobic coatings 9 a lipophilic coating 8th having. The thickness of the lipophilic coating 8th and the lipophobic coating 9 is in relation to the inner ring 10 preferably substantially thinner than shown in the drawing.

In 3 is the bearing ring or the first bearing part 2 out 2 shown in a sectional plan view. The inner ring 10 has a hatched first basic body 3 on, which is hollow cylindrical and extends along the bearing axis L. The cylindrical body 3 has an inner surface 15 on, for example, a shaft can be arranged. On the body is a lipophilic coating 8th arranged, which is the main body 3 completely covered by the outside. The lipophilic coating 8th has a T-shaped cross-section. On the lipophilic coating 8th is a lipophobic coating 9 on both sides of a first part 14 the lipophilic coating 8th arranged. The lipophobic coating 9 thus has an inner recess 13 on, in the first part 14 the lipophilic coating 8th is arranged. The thickness of the lipophilic coating 8th and the lipophobic coating 9 is in relation to the inner ring 10 preferably substantially thinner than shown in the drawing.

4 shows the first embodiment of the bearing 1 in a side view with the inner ring 10 out 2 , Around the first bearing part 2 is a second storage part 5 arranged concentrically. The second bearing part 5 is as an outer ring 11 formed and has a second body 6 with one to the first bearing part 2 facing second tread 7 and one of the first bearing part 2 groundbreaking outer surface 16 on. On the second tread 7 are a lipophilic coating 8th and a lipophobic coating 9 arranged such that the lipophilic coating 8th between the second body 6 and the lipophobic coating 9 is arranged. Between the inner ring 10 and the outer ring 11 is a rolling element room 17 formed in the a plurality of rolling elements 12 is formed, of which only a rolling element 12 shown and further rolling elements 12 are indicated. The thicknesses of the lipophilic coatings 8th and the lipophobic coatings 9 are in relation to the outer ring 11 and inner ring 10 preferably substantially thinner than shown in the drawing.

In 5 is a first storage part 2 a second embodiment of a bearing according to the invention in a sectional plan view. The first bearing part 2 is as an inner ring 10 with a first basic body 3 formed, wherein the first base body 3 an inward facing inner surface 15 having. At the first base body 3 is an outward facing first tread 4 arranged. The first tread 4 has a lipophilic coating 8th and a lipophobic coating 9 on, with the lipophilic coating 8th between the main body 3 and the lipophobic coating 9 is arranged. In this second embodiment, the lipophobic coating covers 9 the lipophilic coating 8th in the radial direction from the bearing axis L to the outside completely. An unillustrated outer ring 11 is constructed accordingly in this second embodiment.

The second embodiment of the bearing 1 has the advantage in operation that only by wear of the lipophobic coating 9 the lipophilic coating 8th exposed in areas of maximum mechanical stress and then causes the presence of sufficient lubricant in these areas. Thus, the second embodiment has the advantage that lubricant in particularly severely worn areas by the lipophilic coating 8th is increasingly provided. The lubricant is thus distributed particularly efficiently in the warehouse. This is particularly important if only relatively little lubricant is present. The thickness of the lipophilic coating 8th and the lipophobic coating 9 is in relation to the inner ring 10 preferably substantially thinner than shown in the drawing.

LIST OF REFERENCE NUMBERS

1

camp

2

First bearing part

3

First basic body

4

First tread

5

Second bearing part

6

Second basic body

7

Second tread

8th

Lipophilic coating

9

Lipophobic coating

10

inner ring

11

outer ring

12

rolling elements

13

Inner recess

14

First part

15

palm

16

outer surface

17

anti-friction

L

bearing axle

100

first process step

200

second process step

300

third process step

400

fourth process step

500

fifth process step

Claims (10)

Camp ( 1 ), comprising a first bearing part ( 2 ) with a first basic body ( 3 ) and a first tread ( 4 ) and a second bearing part ( 5 ) with a second basic body ( 6 ) and a second tread ( 7 ), the first tread ( 4 ) and the second tread ( 7 ) are at least partially facing each other, characterized in that the first tread ( 4 ) at least partially a lipophilic coating ( 8th ) having. Camp ( 1 ) according to claim 1, characterized in that the first tread ( 4 ) a lipophobic coating ( 9 ), wherein the lipophilic coating ( 8th ) substantially between the first base body ( 3 ) and the lipophobic coating ( 9 ) is arranged. Camp ( 1 ) according to claim 1 or 2, characterized in that the second tread ( 7 ) a lipophilic coating ( 8th ) and a lipophobic coating ( 9 ), wherein the lipophilic coating ( 8th ) substantially between the second Basic body ( 6 ) and the lipophobic coating ( 9 ) is arranged. Camp ( 1 ) according to one of the preceding claims, characterized in that the bearing ( 1 ) is designed as a rolling bearing, wherein the first bearing part ( 2 ) as inner ring ( 10 ) or outer ring ( 11 ) and the second bearing part ( 5 ) as outer ring ( 11 ) or inner ring ( 10 ) is formed, wherein between the first tread ( 4 ) and the second tread ( 7 ) at least one rolling element ( 12 ) is arranged. Camp ( 1 ) according to claim 4, characterized in that the rolling element ( 12 ) is arranged in a Wälzkörperkäfig. Camp ( 1 ) according to one of the preceding claims, characterized in that the bearing ( 1 ) is designed as a rolling bearing. Camp ( 1 ) according to one of the preceding claims, characterized in that the lipophobic coating ( 9 ) at least one inner recess ( 13 ), in which a first part ( 14 ) the lipophilic coating ( 8th ), the first part ( 14 ) of the lipophilic coating ( 8th ) of at least two sides of the lipophobic coating ( 9 ) is surrounded. Camp ( 1 ) according to one of the preceding claims, characterized in that in a first area in which in the operation of the warehouse ( 1 ) the greatest forces occur, a layer thickness of the lipophilic coating ( 8th ) thicker than in other areas and / or a layer thickness of the lipophobic coating ( 9 ) is thinner than in other areas. Camp ( 1 ) according to one of the preceding claims, characterized in that between the first bearing part ( 2 ) and the second bearing part ( 5 ) A lubricant is arranged, which has at least one AW and / or EP additive. Method for producing a bearing ( 1 ), characterized by the steps: - providing a first bearing part ( 2 ) with a first basic body ( 3 ) and a first tread ( 4 ); Application of a lipophilic coating ( 8th ) on the first tread ( 4 ); Application of a lipophobic coating ( 9 ) on the lipophilic coating ( 8th ); Providing a second storage part ( 5 ) with a second basic body ( 6 ) and a second tread ( 7 ); and - arranging at least one rolling element ( 12 ) between the lipophobic coating ( 9 ) and the second tread ( 7 ).

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