DD283853A5 - MAINTENANCE-FREE SLIDE BEARING AND METHOD FOR THE PRODUCTION THEREOF - Google Patents

Abstract

The invention relates to a maintenance-free plain bearing, consisting of a metal support and a directly applied thereto, from a copolymer of perfluoroalkyl vinyl ether of the formula: CF 2 CF 4 F, wherein Rf is a perfluoroethyl, perfluoro-n-propyl or perfluoro-n-butyl radical, and Tetrafluoroethylene existing layer which forms either the sliding layer or an intermediate layer on which a sliding layer of plastic is applied forms. Figure {Maintenance-free plain bearing; Metalltraeger; copolymer; perfluoroalkyl; Tetrafluoroethylene; Overlay; Intermediate layer; Plastic}

Description

Maintenance-free bearing and method for its hearing

the

The present invention is a new multi-layer maintenance-free sliding bearing.

of the prior art

Maintenance-free sliding bearings, which consist of a metal carrier and a plastic layer, are z> B. from DS-OS-Nr. 35 34 242 and European Patent Application No. ¹ . 0 217 462 known. Such Mehrsohichtgleitlager consist of a combination of a provided with a Rauhgrundsoicht Hotallträgers steel, bronze or a high-strength aluminum alloy and a sliding layer of a matrix of polytetrafluoroethylene. The Rauhgrundschioht consists of a porous aufgesinterten Bronzesohioht, iron layer or layer of an aluminum alloy. This layer then forms the anchoring material for the polytetrafluoroethylene layer to be applied in the form of a paste or a layer which consists of its copolymers. The high-viscosity paste is rolled and sintered.

A disadvantage of said slide bearing is that the plastic layer made of paste is too thin for many applications. Therefore, the life of the bearings made therefrom is not sufficient. Furthermore, the unevenness occurring during the deformation of the multilayer material can not be reversed.

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If bronze particles are incorporated in the paste in order to improve the thermal conductivity of the plastic, which is important for the bearing, there is a risk that the outer layer will oxidize during production. Such a supporting material is not inert. In particular, there is a risk of destruction Acids · Furthermore, segregation may occur during application of the godfather.

From "Fertigungstechnik und Betrieb ¹¹ 23 (1973)", No. 1, p. 48-49, a film coating by means of conventional polytetrafluoroethylenes is known. Since this material is completely inert with respect to all adhesives, the film is first rendered tacky. That is, the polytetrafluoroethylene films can not be coated in The manner be applied to a support that they are held ei place alone by physical adhesion forces · It is rather necessary to attach the films by means of an adhesive · In this case, therefore, the temperature load depends not only on the type of film but also of the adhesive used

The technical solution according to DE-OS No * 24 01 804 relates to a composite bearing element whose running layer consists essentially of an unfilled plastic «. For this purpose, polyarylene sulfides, epoxy resins, polyamide resins, polyester resins, phenolic resins, polyimide resins, polyamide-inside resins ¹ , polypropylene resins and polysulfone resins are used · These plastic films are not directly attached to the Läetallflache but with the help of suitable adhesives · It is also recommended apply a thin film of lubricating oil to the plastics ·

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In the ER-PS No. 13 54 161 a consisting of tetrafluoroethylene filled with molybdenum sulfide coating is shown. In Adhesives Age, February 1967, p 30-34 polytetrafluoroethylene coated metals are also mentioned. However, the polytetrafluoroethylene is chemically treated to form a compound with the metal support through epoxy groups. Direct application is considered possible only for PEP. It is expressly emphasized that this metal is thermoplastic and can be applied directly to metal, in contrast to tetrafluoroethylene without additional compound layer.

Finally, it should be noted that granular, free-flowing powders known from DE-OS No. 30 21 369 of modified tetrafluoroethylene polymers are known. Tight powders are used for RAM extrusion, as they are particularly well suited for automatic dosing due to their debris yield and free-flowing properties. A suitability of this material for the coating of metals or other materials is not mentioned.

goal of

The aim of the invention is to increase the utility value characteristics of generic maintenance-free plain bearings in a cost effective manner.

That's the one

The object of the invention is to provide a maintenance-free plain bearing, which does not have the disadvantages mentioned and to propose a method for producing such a maintenance-free plain bearing.

According to the invention the object is achieved in such a way that the sliding bearing consists of a metal support and a directly applied thereto, from a copolymer of perfluoroalkyl vinyl ether of the formula:

OP ₂ OP - 0 - R _f ,

wherein K _{f is} a perfluoroethyl, perfluoro-n-propyl or perfluoro-a-butyl radical, and tetrafluoroethylene existing layer which either the sliding layer or a Zwisohensioht on which a sliding layer of plastic is applied, consists «

The layer of a copolymerizate of perfluoroalkyl vinyl ether and tetrafluoroethylene has a thickness which is sufficient for reworking. This can be up to 1.5 mm. The layer is applied directly to the smooth or roughened surface of the metal carrier. The application takes place in the catfish in that the copolymer layer is pressed flat on the metal carrier until the adhesion forces are sufficiently strong to hold it on the metal carrier. A peculiarity of the invention is thus to be seen in the fact that a layer consisting of a copolymer of perfluoroalkyl vinyl ether and tetrafluoroethylene can be applied directly to a metal support. This layer can either serve directly as a sliding layer or be used as an intermediate layer on which, in particular, polytetrafluoroethylene, Polyimide or Plylyetheretherketon (PSEK) adhere well it is not necessary to make the copolymers of perfluoroalkyl vinyl ether and tetrafluoroethylene adhesible or to be fixed by means of an adhesive. In particular, the temperature resistance is therefore no longer dependent on the adhesive used.

As a metal carrier is preferably steel into consideration. Plastics, in particular polytetrafluoroethylene, polyiraid or polyetheretherketone (PBBK) are suitable as material for the sliding layer applied on the base of a copolymer of perfluoroalkyl vinyl ether and tetrafluoroethylene.

One or more fillers may be added to the layer of a copolymer of perfluoroalkyl vinyl ether and / or tetrafluoroethylene and / or the sliding layer of plastic applied thereon to reinforce and / or to improve the thermal conductivity and / or the wear properties. Depending on the objective, coal, aluminum oxide, Ceramic materials, glass, bronze, molybdenum disulphite or silicon carbide (tissue, powder frogs, spheres, fibers) stored ·

Silicon carbide particles also provide good heat transfer properties which do not entail the risk of oxidation during production. The silicon carbide particles are also acid resistant and inexpensive. They are also lighter than metal particles, especially bronze, so that in the manufacture of the copolymer of perfluoroalkyl vinyl ether and copolymer Tetrafluoroethylene there is no danger of defecating. On the bearing side, on the other hand, such fillers should be stored that improve the sealing properties of the bearing. In the invention, a filler content of 1 to 40 Vol .- # can be realized because the filler does not need to be rolled as in the prior art, but is already present in the layer of a copolymer of perfluoroalkyl vinyl ether and tetrafluoroethylene.

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Particular preference is given to 5 to 30% by volume. The thickness of the layer of a copolymer of perfluoroalkyl vinyl ether and tetrafluoroethylene (up to 1.5 mm) is very precisely adjustable, which is not possible when rolling a paste according to the prior art at thicknesses of more than 50 μm.

In experiments, the plain bearing during continuous operation temperatures up to 260 ⁰ C, depending on the material used, withstand, without it to Abl'jsen the layer of a copolymer! sat came from perfluoroalkyl vinyl ether and tetrafluoroethylene. Short-term higher Temperaturbelastuagen survived the sliding bearing without damage ·

Ausführunasbelspiel

The solution according to the invention will be explained in more detail below in an exemplary embodiment with reference to the associated drawing, in which the structure of the plain bearing material according to the invention is shown.

On a metal layer 1, a layer 2 of a copolymer of perfluoroalkyl vinyl ether and tetrafluoroethylene is provided on which there is the layer 3 of plastic applied thereon.

The following examples illustrate the present invention in more detail.

IfS / Si

example 1

Trials with polytetrafluoroethylene and etched metal supports (VA-Metalcplast)

A steel plate was coated. Origin of the sliding layer *

Slip layer thickness: heated plate temperature: heated plate pressure: origin of the intermediate layer: thickness of the intermediate layer before coating:

Thickness of the intermediate layer after coating:

Result of the gravity test:

- 106 H / cm ²

- 70 K / cm ²

Metalloplast ^R MP3 («PTFE + Stainless steel fabric

+ Glass + graphite) 0.48 mm

375 - 385 ⁰ C6-10 bar

Hostaflon.RTM

0.25 mm

approx. 0.20 mm

4025

at room temperature at 200 ° C

Example 2 Trials with etched and unetched metal carrier

Thickness of the sample before coating: Thickness of the sample after coating: Temperature of the heated plate: Pressure of the heated plate: Intermediate layer used: 1.10 mm 1.00 mm 290 ⁰ C 6-10 bar Hostaflon ^(R) ET 6235 (ETPE)

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Sliding layer as ± a example 1

Etched and unetched VA Het & loplast was tested at rising temperatures «

Results of the shear force tea:

Temperature etched metaloplastic unetched MP

(N / cm ² ) (ir / cja ² ) Room temp. 133 91

100 ⁰ C 125 77

150 ⁰ C 107 62

200 ⁰ 58 58 26

Sliding layer: PTPE filled with 35 % coal

Beading: 0,5 rome

Interlayer: SFM with 30 % SiC Thickness: 0.25 mm

Heated plate temperature: 390 ⁰ C heated plate pressure: 2 bar

Result of the shear force test:

No dissolving of the foil, foil ruptures ·

Example 4 (no intermediate layer)

Sliding layer: TFM + 25 % + 5 % graphite (unetched) (pressed directly onto steel)

Dowel: 0.25 mm

Temperature of the heated plate: 380 ° C

Pressure of the heated plate: 2 bar

Result of the shear force test:

At room temperature: β 1500 N / onr

At 100 ° Oi »1080 N / cm ²

At 150 ° C: «220 H / cm ²

Sliding layer: Polyimide (Kapton type M (DuPont)) Thickness: 0.125 mm

Adhesive film: 077M (as in Example 1) Thickness: 0.25 mm

Heated plate temperature: 395 ° G Pressure of the heated plate: 50 bar

Result of the Soherkrafttests: No detachment, foil tears ·

Example 6-8 Preliminary Conditions:

Sample size: 2f> χ 25 mm

Withdrawal force: 0.100 kg

Temperature progression: 5 ° 0 rising per level

3 min. rising temperature 3 min · holding temperature

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Example 6

Sliding layer Interlayer t iietalloplast MP2 («plastic + bronze fabric)

BTP2

Preparation of the sample: Metalloplast MP2 + EXFE film were

on a plate (0.5 mm chromated) at 310 ° C mold temperature, 25 see.

Holding time and 3 t pressing pressure applied.

Result of the shear test: 5 samples dropped at 300 ° 0

Example 7

Sliding layer: intermediate layer:

Metalloplast UP2 PFA film

Preparation of the sample:

Metalloplast MP2 + PFA film was coated on a sheet metal (0.5 mm chromated) 385 ° C tool temperature, 25 see

Holding time 3 t pressing pressure applied.

Shear test result: 5 samples dropped at

380 °, 385 °, 387 °, 390 ° C.

Example 8

Sliding layer: Metallop] ast MP2

Interlayer: TFM film

Preparation of the sample: Metalloplast MP2 + TFM film were

printed on a sheet (0.5 mm chromated) at 3 t pressing pressure.

Shear test result: no samples dropped at 410 ° C.

In the examples:

PTPE β polytetrafluoroethylene

TFM modified polytetrafluoroethylene (a copolymer! Sat of perfluoroalkyl vinyl ether and

Tetrafluoroethylene according to the invention) STFE a copolymer of ethylene and tetrafluoroethylene.

This is a thermoplastic

Fluoropolymer PFA β copolymer of perfluorovinyl ether and tetrafluoroethylene. This product is chemically similar to the TFM. However, it is thermoplastic due to its higher ether content.

Claims (2)

IfUSl Berlin, 12.08 · 1989 AP P 16 0/328 038 - 6 72 272/25/35 claims 1 · Maintenance-free plain bearing, characterized in that it consists of a metal support and a directly dareu.t applied, from a Copolyaerisat of Perfluoralkyl \ lnyl ether of the formulas CP ₂ - CP - 0 - Hj, wherein R ^ is a perfluoroethyl, perfluoro-n-propyl or perfluoro-n-butyl radical, and {tetrafluoroethylene layer consisting of either the sliding layer or an intermediate layer on which a sliding layer of plastic is applied 2 · sliding bearing according to claim 1, characterized in that the bead of the sliding layer is up to 1.5 mm. 3 plain bearing according to one of claims 1 or 2, characterized in that the metal carrier has a smooth surface. 4 plain bearings according to one of claims 1 or 2, characterized in that the metal carrier has a roughened surface. 5 plain bearing according to one of claims 1 to 4, characterized in that the metal support consists of steel. -2- 1/31 Sh 6. plain bearing according to one of claims 1 to 4, characterized in that the applied on the layer of a copolymer of perfluoroalkyl vinyl ether and tetrafluoroethylene overlay is a plastic film »which is perforated and / or permeable to air · Sliding bearing according to one of Claims 1 to 6, characterized in that the sliding layer applied to the base of a copolymer of perfluoroalkyl vinyl ether and tetrafluoroethylene consists of polytetrafluoroethylene or polyimide or polyether ketone (PSKK). 8. plain bearing according to one of claims 1 to 7, characterized in that the so-coated from a copolymer of perfluoroalkyl vinyl ether and tetrafluoroethylene sliding layer made of plastic for reinforcing and / or improving the thermal conductivity and / or the wear properties of one or more FUlIstoff (e) is (are) added 9 · plain bearing according to claim 8, characterized in that the fillers fabric, powder or fibers of coal, alumina, ceramics, glass, bronze, Molybdändisuliit or silicon carbide are. 10. plain bearing according to one of claims θ or 9, daduroh characterized in that the filler is 1 to 40 vol .-%. 11 · plain bearing according to claim 9, characterized in that the filler content is 5 to 30 vol. % . -3- in η ι 12λ plain bearing according to claims 1 to 11, characterized in that the Zwisohensicht consisting of a copolymer! Sat of tetrafluoroethylene and Perfluorkylvinylether as fillers fabric, powder or fibers of carbon, alumina, Keremilcwerkstoffen, glass, bronze, molybdenum disulfite or silicon carbide. 13th method for producing a maintenance-free plain bearing daduroh characterized in that the film is connected flat, under pressure and heat to the carrier · 14. A method according to claim 13, characterized in that the surface of the metal carrier is roughened before the application of the sliding layer. uc