WO2012080028A2

WO2012080028A2 - Sealing device having a functional coating

Info

Publication number: WO2012080028A2
Application number: PCT/EP2011/071831
Authority: WO
Inventors: Wolfgang Schmidt-Aursch; Tim Matthias Hosenfeldt
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2010-12-17
Filing date: 2011-12-06
Publication date: 2012-06-21
Also published as: WO2012080028A3; DE102010063393A1

Abstract

The invention relates to a sealing device (1a) for separating material spaces (12a, 13a) contacting each other at a sealing gap (11a) between two machine components, such as in rolling bearings (19) such as wheel bearings and the like. In order to achieve an improved embodiment of the sealing gap (11a) under spatially constrained, tight conditions, at least one functional coating (25, 26, 27, 28, 29, 30) at least partially reducing material penetration through the sealing gap (11a) is applied to at least one segment of the sealing device (1a).

Description

Name of the invention

Sealing device with functional coating Description

Field of the invention

The invention relates to a sealing device for the separation of fabric spaces which contact one another at a sealing gap between two machine components.

Background of the invention

Generic sealing devices are used, in particular, in machine components that are moved relative to one another, in order, for example, to separate an inner material space, such as lubricant space, from an outer material space such as outer space, which may contain contaminants, water and the like. For example, roller bearings such as wheel bearings, spindles rotatably arranged in a housing and / or axially displaced spindles, housing parts with components rotating therein, such as shafts and the like, may be provided with corresponding sealing devices.

In such applications of sealing devices are often only small installation spaces and thus small sealing distances available that allow only an insufficient separation of the fabric spaces from each other, so that, for example, on the one hand lubricant from the lubricant space in the outside and on the other hand water from the outside into the outside Lubricant space can penetrate. Furthermore, the friction of the sealing device and an occurring wear should be low, which is why non-contact sealing devices are provided with a narrow sealing gap. By using sealing surfaces provided on one section, such as sealing lips, which form a static or dynamic sealing contact with the other section, it is possible, with reference to FIG. an improved seal of an improved seal of a sealing device shown for example in DE 10 2005 035 027 A1 can be achieved. However, the sealing contacts must, in turn, be protected against wear by precluding the entry of soiling into correspondingly formed sealing gaps. As shown in the sealing device, a sealing device is preferably formed from sheet metal parts, which are approximated to form a sealing gap to each other and with the machine components - formed here as races ring parts - connected and optionally provided with sealing surfaces such as sealing lips.

Object of the invention

The object of the invention is the development of such a sealing device with improved sealing properties in a small space.

General description of the invention

The object is achieved by a sealing device for separating fabric seams contacting one another at a sealing gap between two machine components, in which at least one functional coating which at least partially reduces a material passage through the sealing gap is applied to the machine components forming the sealing gap.

In this way, an improved separation of the fabric spaces, for example, a lubricant space from the outside and outside environment, achieved by the physical properties of the adjacent walls of the sealing device forming walls are adjusted by means of one or more functional coatings so that the mass flow through the sealing gap is difficult. In this case, a functional coating can be completely or only partially applied to a corresponding section. In addition, a plurality of different functional coatings can be distributed over one or both sections, so that they reinforce their effect. For example For example, functional coatings with the same or opposite physical properties can be arranged on both walls of the sections lying opposite each other. Alternatively or additionally, different functional layers with physical properties increasing or decreasing over the diameter can be arranged on different ring segments on different diameters.

In conjunction with a corresponding embodiment of the sections of the machine components, for example, opposite, forming the sealing gap, annular sheet metal parts, a combination with one or more arranged on these functional coatings is particularly suitable to achieve a Schmierstoffabweisende effect in the range of delimitation to the lubricant space in order to reduce a friction caused by the lubricant between the mutually moving sections of the machine components. A lubricant-repellent formation of a functional coating in the adjacent region of the sections to the lubricant space causes a retention of the lubricant in this, so that penetration of the lubricant into the sealing gap can already be prevented there. A lubricant-absorbing effect can be used by an appropriate composition of the functional coating, in particular in the region of contacting a sealing surface with a counter-sealing surface of a dynamic seal to improve the hydrodynamic lubricating film. Furthermore, in the sealing gap itself, a lubricant-attracting effect of the functional coating can have the advantage that hydrophobic conditions are set in the sealing gap, so that the penetration of water from the outside is prevented. A water-repellent effect of a functional coating in the area of the sealing gap or on contact surfaces of a contacting seal can reduce the delivery of water into the sealing gap. In this case, corresponding capillary effects, which allow a corresponding delivery of water through the sealing contact and / or the sealing gap, are advantageously prevented. The at least one functional layer, preferably arranged in the region of the entrance of the sealing gap or in this at the corresponding section segments of the sealing device, according to an advantageous embodiment may have adhesion-reducing properties. By means of such functional coatings, the capillary action of the sections themselves and / or, if appropriate, of a sealing gap acting as a capillary with sections of the machine components which are closely spaced from one another can be reduced. In this case, a reduction is achieved for example by functional coatings such as fluoropolymers such as polytetrafluoroethylene (PTFE), carbon coatings and the like.

Functional coatings or segments of these surfaces for adjusting lipophoric or oleophobic properties, ie lubricants in the form of oil and grease repellent surfaces of the sections are preferably formed from fluoropolymers such as polytetrafluoroethylene (PTFE) and the like. Functional coatings having hydrophobic properties are similarly adjusted from fluoropolymers such as polytetrafluoroethylene (PTFE), paints and the like. The difference to the lipophilic or oleophilic adjustment of the functional coating is in particular its local position in the region of the lubricant space on the one hand and the delimitation of the sealing gap to the outside on the other hand. In order to hold lubricant, for example, at a specific point such as a contacting sealing contact, it has proved to be advantageous if the functional coating has lipophilic or oleophilic properties, that is, improves the attachment of lubricant to a surface or a surface section. For this purpose, burnishing and the like are suitable. For setting functional coatings with hydrophilic properties, for example, for concentration of water in front of the sealing gap, so that targeted discharge before the sealing gap, for example a dripping promoted and penetration into the sealing gap is reduced, a corresponding functional coating of metal-containing carbon compounds, for example diamond-like carbon layers with metal deposits (Me-DLC) are provided. In order to provide at least partial regions of the sections of the machine components for both water and lubricant with increased adhesion, functional coatings with so-called amphiphilic properties can be provided. Such coatings can be formed, for example, from surfactants. In contrast, the parts or the entire surface of one or both sections can be provided with a so-called amphiphobic functional layer, in which the adhesion of water and lubricant is difficult. Coatings of preferably crack-free chromium and fluoropolymers, in particular polytetrafluoroethylene (PTFE), have proved to be advantageous for this purpose.

The proposed functional coatings are suitable for sealing devices, for example in the form of one or more sections forming the sealing gap, which approach each other without contact and thus form the sealing gap. This can be provided with the machine components, made of sheet metal or optionally made of plastic annular sealing parts, which are coated with a single or more types of functional coating, each one or more functional sections are formed, depending on their local location, the function of this increase by preventing lubricant from escaping and water from entering the lubricant space and / or the seal gap. Alternatively or in addition to the sealing gap, the sealing device may be provided with a contacting sealing contact of the sealing elements. By means of the functional coating, it is additionally possible to stabilize a hydrodynamic lubricant contact in the area of the contacting seal.

According to the inventive idea, the sealing device is preferably used in rotating devices in which two or more ring parts rotate about a common axis of rotation, for example in pivot bearings such as rolling or sliding bearings, freewheels, housing parts with rotating shafts, spindle bearings and the like. This can be done on a rotating or non-rotatably arranged outer part such as outer ring or housing part may be arranged one or more sealing parts, which form with one or more sealing parts, which are arranged on a rotating shaft, a rotating or fixed inner ring, the sealing gap and / or the dynamic seal-sealing contact ,

It is understood that hydrophobic functional coatings may be non-polar and may correspond to oleophilic or lipophilic functional coatings. In the same way, hydrophilic functional coatings can be formed polar and correspond to oleo- or lipophobic functional coatings. Since lubricants are formed as oils or fats and are generally oleo or lipophilic, a uniform term in the form of oleophilic and, for the contrary, oleophobic is used hereinafter to describe the properties of lubricant and the surfaces of the sealing device. Furthermore, it is understood that the inventive sealing device containing arrangements such as shaft seals, pivot bearings such as rolling or plain bearings, freewheels, spindle bearings and the like are summarized by the inventive idea. Brief description of the drawings

The invention will be explained in more detail with reference to the embodiments illustrated in Figures 1 to 5. Showing:

1 shows a sealing device of a shaft seal in partial section,

FIG. 2 shows a schematic detail of the sealing device of FIG. 1,

FIG. 3 shows a sealing device provided with functional coatings on a rolling bearing in partial section,

FIG. 4 shows a sealing device in accordance with FIG. 3 with a functional coating formed with changed physical properties Partial section,

Figure 5 is a sealing device of Figure 4 similar sealing device, and

FIG. 6 shows a partial section of a sealing device containing only a section forming the sealing gap.

Detailed description of the drawings

FIG. 1 shows the sealing device 1 for sealing the machine component 2 embodied as a housing component 4 with respect to the machine component 3 embodied as a shaft 5. The sealing device 1 contains a shaft sealing ring 6 such as a radial shaft sealing ring which is fastened to the machine component 2 by means of the carrier part 7 and by means of the membrane 8 with the sealing lip 9 having the sealing lip forms a dynamic sealing contact against the counter-sealing surface 10 of the machine component 3. The sealing device 1 separates the fabric spaces 12, 13 from one another by means of the sealing gap 1 provided at the sealing edge 9, wherein the material space 12 as at least partially filled with lubricant or wetted lubricant space and the space 13 as an external space in which contamination and water pollution can occur formed are. In the embodiment shown, the object is to keep the sealing gap 1 1 permanently lubricated to keep wear of the sealing lip low and to avoid dry running of the sealing edge 9 of this on the shaft 5. At the same lubricant should not escape from the space 12 and dirt and water from the space 13 are prevented from entering the space 12.

In FIG. 2, a schematic section of the sealing device 1 of FIG. 1 with functional coatings 14, 15, 16, 17 with different physical properties attached to this task is shown in detail. To the oleophil designed lubricant 18 in the region of the sealing gap 1 1, which is shown here oversized and can be made very tight by the contact of the membrane 8 with the sealing contact forming sealing edge 9 of the sealing lip on the mating surface 10, is on the shaft 5, the functional coating 14 in the region of the sealing contact of the sealing edge 9 of the sealing lip on the shaft 5 oleophilic formed, for example, from metal-containing, diamond-like carbon such as Me-DLC, so that the functional coating 14 favors the attachment of the lubricant 18. Respectively axially adjacent to the functional coating 14, the oleophobic functional coating 15 is applied to the shaft 5, so that the attachment of lubricant 18 is made difficult here.

In the same way, the membrane 8 and the sealing lip are configured such that the sealing edge 9 oleophilic and the axially adjacent regions of the sealing device 1 are formed oleophobic, so that the oleophilic lubricant 18 is preferably attached to the oleophilic sealing edge 9 and held there. For this purpose, the membrane 8 may be formed of oleophobic material and an oleophilic functional coating may be provided on the sealing edge 9. In the embodiment shown, however, the membrane 8 is made of oleophilic material, wherein the axially adjacent the sealing edge 9 areas with oleophobic functional coatings 16, 17 are provided. In this case, the functional coatings 16, 17 can be applied individually to the membrane 8 or produced as a layer, wherein the region at the sealing edge 9 is freed from the functional coating, for example, chemically or abradingly. In addition, due to their hydrophobic design, the functional coatings 15, 16 have a repellent effect on water, so that optionally penetrating water is forced off the sealing gap 11. It is understood that in lipophobic lubricants, the properties of the functional coatings used can be interpreted in reverse. Figure 3 shows the introduced between the races 20, 21 of the rolling bearing 19 sealing device 1 a with the formed from sheet metal or plastic parts sections 22, 23, 24. The sections 22, 23 are fixed to the raceway 20 and the section 24 is fixed connected to the raceway 21 and bil- a non-contact sealing of the at least partially filled with the lubricant 18a material space 12a relative to the space 13a in the form of the outer space of the bearing 19. The formed between the sections 22, 23, 24 and labyrinth-deflected sealing gap 1 1 a ensures the separation of the fabric spaces 12a, 13a. To support this separation, the walls of the sections 22, 23, 24 are provided with functional coatings 25, 26, 27, 28, 29, 30. The oleophilic lubricant 18a is repelled at the oleophobic functional coating 25. Furthermore, water particles 31 are pushed against the hydrophobic functional coating 30, so that wetting of the section 23 by water does not occur and thus water is retained by the sealing gap 11a. The labyrinth-shaped sealing gap 11a facing walls of the sections 22, 23, 24 are each provided with an oleophobic and hydrophobic functional coating 26, 27, 28, 29, for example PTFE, so that both the oleophilic lubricant 18a in the first part of the sealing gap a between the sections 22, 24 and water in the second part of the sealing gap 1 1 a between the sections 23, 24 is retained. If, nevertheless, lubricant particles 32 penetrate into the sealing gap 11a, one or more return channels (not shown) may be provided on the outer circumference, which are provided, for example, spirally in the direction of rotation of a rotating race 20, so that a preferred return of the lubricant particles in the space 12a can be provided. The sealing devices 1 b, 1 c of the rolling bearing 19 a, 19 b of Figures 4 and 5 are in different configurations of sections 22 a, 22 b, 23 a, 23 b, 24 a, 24 b with respect to the arrangement of the functional coatings 34 a, 34 b, 35 a, 35 b, 36 a, 36 b , 37a, 37b and 34c, 34d, 35c, 35d, 36c, 36d, 37c, 37d are of similar design. In order to achieve an improved sealing of the labyrinthartig folded sealing gaps 1 1 b, 1 1 c by means of the lubricant insert 33, 33a, for example, from fat and to stabilize them radially outward in the sealing gap 1 1 b, 1 1 c, the sections 22a , 22b, 23a, 23b, 24a, 24b differently coated in the radial direction. The lubricant Insert 33, 33a is oleophilic and is formed by the radially outer, also oleophilic trained functional coatings 34a, 35a, 36a, 37a and 34c, 35c, 36c, 37c in the radially outer region of the sections 22a, 23a, 24a and 22b, 23b, 24b stabilizes and thus closes the two by these separate parts of the sealing gap 1 1 b or 1 1 c. The radially inner, hydrophobic and oleophobic trained functional coatings 34b, 35b, 36b, 37b and 34d, 35d, 36d, 37d prevent slipping of the lubricant liner 33, 33a and penetration of the lubricant 18b and 18c of the fabric space 13b and 13c and penetration of water from the material space 13b and 13c in the sealing gap 1 1 b or 1 1 c. In addition, the sections 23a, 23b may be hydrophobically coated on the fabric spaces 13b, 13c. It is understood that these hydrophobic properties can also be achieved by functional coatings which, like PTFE, have hydrophobic and oleophobic properties.

FIG. 6 shows the roller bearing 19c with the simple, non-contact sealing device 1d, in which only a section 22d is provided which forms the sealing gap 1d radially inwards relative to the raceway 21a. For the effective separation of the fabric spaces 12d with the oleophilic lubricant 18d and the optionally water-loaded material space 13d, the oleophobic and hydrophobic functional coatings 38, 39 are provided on the outer circumference of the race 21a and on the inner circumference of the portion 22d, so that the lubricant 18d is prevented from escaping and water from entering the material space 12d. LIST OF REFERENCE NUMBERS

sealing device

a sealing device

b sealing device

c sealing device

d sealing device

machine part

housing component

wave

Shaft seal

support part

membrane

sealing edge

0 mating surface

1 sealing gap

1 a sealing gap

1 b sealing gap

1 c sealing gap

1 d sealing gap

2 fabric room

2a room space

2b fabric space

2c room space

2d fabric room

3 space

3a room space

3b room space

3c fabric space

3d cloth room

4 functional coating

5 functional coating functional coating

functional coating

Lubricant Lubricant Lubricant Lubricant Lubricant

roller bearing

a rolling bearing

b rolling bearings

c rolling bearings

race

a race

section

a section

b section

d section

section

a section

b section

section

a section

b section

functional coating

water particles

Grease particles

lubricant deposit a Lubricant inlay Functional coatingb Functional coatingc Functional coatingd Functional coatinga Functional coatingb Functional coatingc Functional coatingd Functional coatinga Functional coatingb Functional coatingc Functional coatingd Functional coatinga Functional coatingb Functional coatingc Functional coatingd Functional coating Functional coating Functional coating

Claims

claims

1. Dichteinnchtung (1, 1a, 1c, 1d) for the separation of itself at a sealing gap (11, 11a, 11b, 11c, 11 d) between two machine components (2, 3) touched fabric spaces (12, 12a, 12b, 12c, 12d, 13, 13a, 13b, 13c, 13d), characterized in that on at least a portion (22, 22a, 22b, 22d, 23, 23a, 23b, 24, 24a, 24b) of the machine components (2, 3 ) at least one at least partially a material passage through the sealing gap (11, 11a, 11b, 11c, 11 d) decreasing functional coating (14, 15, 16, 17, 25, 26, 27, 28, 29, 30, 34a, 34b, 35a , 35b, 36a, 36b, 37a, 37b, 38, 39).

2. sealing device (1, 1a, 1b, 1c, 1d) according to claim 1, characterized in that the at least one functional coating (15, 16, 17, 25, 26, 27, 28, 29, 30, 34b, 34d, 35b , 35d, 36b, 36d, 37b, 37d, 38, 39) has adhesion-reducing properties.

3. sealing device (1, 1b, 1c) according to claim 1 or 2, characterized in that the at least one functional coating (14, 34a, 34c, 35a, 35c, 36a, 36c, 37a, 37c) has oleophilic properties.

4. sealing device (1, 1a, 1b, 1c, 1d) according to one of claims 1 to 3, characterized in that the at least one functional coating (15, 16, 17, 25, 26, 27, 28, 29, 30, 34b , 34d, 35b, 35d, 36b, 36d, 37b, 37d, 38, 39) has oleophobic properties.

5. sealing device (1, 1a, 1b, 1c, 1d) according to one of claims 1 to 4, characterized in that the at least one functional coating (15, 16, 17, 25, 26, 27, 28, 29, 30, 34b , 34d, 35b, 35d, 36b, 36d, 37b, 37d, 38, 39) has hydrophobic properties.

6. sealing device (1 a, 1 b, 1 c, 1 d) according to one of claims 1 to 5, characterized in that the sealing gap (11 a, 11 b, 11 c, 1 d) forming Sections (22, 22a, 22b, 22d, 23, 23a, 23b, 24, 24, 24b) are non-contact approached each other.

Sealing device (1) according to one of claims 1 to 5, characterized in that the sealing gap (1 1) forming portions additionally form a sealing contact.

Sealing device (1 a, 1 b, 1 c, 1 d) according to one of claims 1 to 7, characterized in that at least one portion (22, 22a, 22b, 22d, 23, 23a, 23b, 24, 24a, 24b) made of sheet metal or plastic and is firmly connected to one of the machine components.

Sealing device (1 a, 1 b, 1 c, 1 d) according to one of claims 1 to 8, characterized in that the machine components are rotatable about a common axis of rotation ring parts.