RU2044178C1 - Unserviceable sliding bearing - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: bearing is composed of metal base and layer applied to the base. The layer consists of copolymerizate made from fluoroalkylvinylether of CFG₂=CF-O-R_f formulae where R_f the residual of the perfluoroethyl or perfluoro-n-propyal or perfluoro-n-butyl and tetrafluoroethylen. This layer is sliding layer or intermediate layer whereto the sliding layer made of synthetic material is applied. The width of the layer is sufficient to be processed additionally. EFFECT: improved design. 13 cl, 1 dwg

Description

 An object of the present invention is a new maintenance-free multilayer plain bearing.

 Known plain bearings that do not require maintenance, which consist of a metal base and a plastic layer (application Germany N 3534242 and European application 0217462). Such multilayer plain bearings consist of a combination of a metal base provided with a rough layer made of steel, bronze or high-strength aluminum alloy, and a plain layer, which is a polytetrafluoroethylene matrix. The roughened base layer is a sputtered porous layer of bronze, iron or aluminum alloy. This layer forms a fixing material for the polytetrafluoroethylene layer applied in the form of a paste or a layer consisting of its copolymers. High viscosity paste rolls and sinter.

 The disadvantage of this bearing is the lack of service life.

 Since bronze particles are introduced into the paste in order to improve the thermal conductivity of the plastic, there is a danger of oxidation of the outer layer during manufacture. Such bearing material is also not inert, and the possibility of destruction by acids is especially dangerous. In addition, delamination may occur when applying the paste.

 Known film coating of conventional polytetrafluoroethylene "Fertigungotehnik und Betrib", 23 (1973), no. 1. sec 48-49). Since this material is inert to all adhesives, the film is first made adhesive, i.e. polytetrafluoroethylene films cannot be applied to the base in such a way that they are fixed on it only due to the physical adhesion forces. Moreover, the films must be fixed with glue, in this case the ability to withstand thermal loads depends not only on the type of film, but also on the glue used.

 The application of Germany N 2401804 relates to a combined bearing element, the running layer of which consists of filled plastic. For this, polyarylene sulfides, epoxies, polyamide resins, polyester resins, phenoxy resins, polypropylene and polysulfone resins are used. These synthetic films are fixed to a metal surface either directly or using suitable adhesives. In addition, a thin film of lubricating oil is recommended for plastics.

 French Patent No. 1354161 describes a tetrafluoroethylene coating filled with molybdenum disulfide.

 Known metal coated with polytetrafluoroethylene. However, polytetrafluoroethylene is chemically processed; therefore, a compound with a metal base is formed due to epoxy groups. Direct application is considered possible only for FEP. This material is thermoplastic and, unlike tetrafluoroethylene, without an additional bonded layer cannot be applied directly to the metal.

From the application of Germany N 3021369 known granular granular powders from modified polymers of tetrafluoroethylene. It is, in particular, a copolymerizate of a perfluoroalkylvinyl ether of the formula: CF ₂ CF —OR _f , where R _{f is the} residue of perfluoroethyl, perfluoro-n-propyl or perfluoro-n-butyl, and tetrafluoroethylene. This powder is subjected to R _am extrusion, since it is suitable for automatic dosing due to its bulk density and flowability.

 The closest in technical essence to the invention is a sliding bearing, consisting of a metal base and a sliding layer deposited on it.

 The objective of the invention is to create a plain bearing that does not require maintenance.

The proposed plain bearing consists of a metal base and deposited directly on it consisting of a perfluoroalkyl vinyl ether ether copolymer of the formula: CF ₂ CF OR _f , where R _{f is the} remainder of perfluoroate, perfluoro-n-propyl or perfluoro-H-butyl and tetrafluoroethylene layer, which is a slip layer or an intermediate layer onto which a slip layer of synthetic material is applied.

 The copolymerizate layer of perfluoroalkyl vinyl ether and tetrafluoroethylene has a thickness sufficient for further processing; it can be up to 1.5 mm. The layer is applied directly to the smooth or rough surface of the metal base. The application is carried out in such a way that the copolymerizate layer is pressed against the metal base until the adhesion forces are large enough to fix the layer on the metal base.

 A feature of the invention is that the layer can serve as a slip layer or as an intermediate layer with which it adheres well, for example, polytetrafluoroethylene, polyimide or polyetheretherketone (OREEK), therefore it is not necessary to tack the perfluoroalkylvinyl ester and tetrafluoroethylene copolymerizate or to fix it with glue . In particular, now the resistance to thermal stress does not depend on the adhesive used.

 As the metal base, steel is preferred. Synthetic materials such as polytetrafluoroethylene, polyimide or polyetheretherketone (PEEK) are suitable for the slip layer applied to the copolymerizate layer of perfluoroalkyl vinyl ether and tetrafluoroethylene.

 One or more fillers may be introduced into the copolymerizate layer of perfluoroalkylvinyl ether and tetrafluoroethylene and / or into the slip layer of synthetic material applied to the copolymerizate layer to enhance and / or improve thermal conductivity and / or wear resistance. In accordance with the intended purpose, for example, coal, alumina, ceramic materials, glass, bronze, molybdenum disulfide or silicon carbide (cloth, powder, balls, fiber) are added.

 Using particles of silicon carbide, good heat-conducting properties are provided, and this does not entail the risk of oxidation during manufacture. In addition, silicon carbide particles are acid resistant and cheap.

 They are lighter than metal particles, for example, of bronze, therefore, in the manufacture of a layer of a copolymerizate of perfluoroalkyl vinyl ether and tetrafluoroethylene there is no danger of delamination. On the contrary, on the support side, it is necessary to use a filler that increases the wear resistance of the bearing. The proportion of filler may be from 1 to 40 vol. since the filler does not need to be rolled into the layer, as before, but it is already in the copolymerizate layer of perfluoroalkyl vinyl ether and tetrafluoroethylene. A content of from 5 to 30 vol.% Is particularly preferred. The thickness of the layer of copolymerizate of perfluoroalkyl vinyl ether and tetrafluoroethylene (up to 1.5 mm) is controlled with great accuracy.

In the experiments, the slide bearing (depending on the material used) to withstand prolonged operation at temperatures up to 250 ^{° C,} and it did not lead to the separation of layers of the copolymer of tetrafluoroethylene and perfluoroalkylvinylether. For a short time, the sliding bearing withstands higher temperatures without damage.
The drawing shows the proposed sliding bearing. The metal layer is indicated by 1, a layer of a copolymerizate of perfluoroalkyl vinyl ether and tetrafluoroethylene 2, and a layer of plastic 3 applied to it.

 PRI me R 1. An experiment with polytetrafluoroethylene and etched metal base.

As a metal base, a steel plate was coated. PTFE slip layer + fabric
from stainless
blowing
steel + glass +
+ graphite
The thickness of the slip layer, 0.48 mm
The temperature of the heated plate, ^about With 375-385
Pressure on the heated plate, MPa 0.6-1.0 Intermediate layer TFM
Intermediate thickness
layer before coating, mm 0.25
Intermediate thickness
layer after coating, mm approx. 0.20
Shear test results:
τ 106 N / cm ² at room
temperature τ 70 N / cm ² at 200 ^о С
PRI me R 2. An experiment with etched and non-etched metal base.

As a metal base Steel plate
The thickness of the sample before coating, mm 1.10
Thickness of the sample after coating, mm 1.00 Temperature of the heated plate, ^о С 290
Pressure on a heated plate, MPa 0.6-1.0 Intermediate layer ETFE
The slip layer as in example 1
Shear test results:
Tempera- with grass-without grass-
tour, niem, laziness,
^o C N / cm ² N / cm ²
room 133 91 100 125 77 150 107 62 200 58 26 PRI me R 3. As a metal base Steel
plate
PTFE slip layer with 35%
coal as
filler
as
films Thickness, mm 0.5 Intermediate layer TPM with 30% SiC Thickness, mm 0.25 Temperature of the heated plate, ^о С 390 Pressure on the heated plate, MPa 0.2 Results of shear tests: Departments
no film
going on
film
torn apart
PRI me R 4.

As a metal base Steel plate Sliding layer TFM + 25%
glass + 5%
graphite
pressed on
directly
on steel Thickness, mm 0.25 Intermediate layer No Temperature of the heated plate ^o С 380 Pressure on the heated plate, MPa 0.2 Results of shear test: At room temperature τ = 1500 N / cm ² at 100 ^о С τ = 1080 N / cm ² at 150 ^о С τ = 220 N / cm ²
PRI me R 5.

As a metal base Steel plate Slip layer Polyamide Thickness, mm 0.125 Intermediate layer TPM (as in
example 1)
in the form of a film Thickness, mm 0.25 Temperature of a heated plate, ^о С 395 Pressure on a heated plate, MPa 5.0 Shear test result: Film compartments
not happening,
the film is torn. PRI me R 6. Test conditions: Sample size 25x25 mm ² Pull force 0.1 kg Temperature change Step
increase from
5 ^o C interval,
increase in
for 3 minutes
maintaining on
one level 3 min. PTFE + bronze slip layer
fabric Intermediate layer TFM in the form of
films Sample production Slip layer
and intermediate
layer were
pressed
per sheet (0.5 mm chrome
tinned) with
effort
. compaction m 3 Test results Shear: 410 ^C. When none
the sample was not
sent to
waste.

In the examples, the following notation was used:
PTFE polytetrafluoroethylene, TFM modified polytetrafluoroethylene (copolymerizate of perfluoroalkyl vinyl ether and tetrafluoroethylene according to the invention), ETFE copolymer of ethylene and tetrafluoroethylene; in this case we are talking about a thermoplastic fluoropolymer; PFA copolymer of perfluorovinyl ether and tetrafluoroethylene according to the invention. This product is chemically similar to TFM, but is thermoplastic due to its higher ether content.

Claims (13)

1. A SLIDING BEARING, NO SERVICE REQUIRED, consisting of a metal base and a sliding layer deposited on it, characterized in that the sliding layer is made of a perfluoroalkyl vinyl ether ether copolymer of the formula CF ₂ CF-O-Rf, where Rf is the remainder of perfluoroethylene, or perfluoro-H- propyl, or perfluoro-N-butyl and tetrafluoroethylene.  2. The bearing according to claim 1, characterized in that it further comprises a sliding layer of plastic deposited on top of an existing sliding layer.  3. The bearing according to claim 1, characterized in that the thickness of the sliding layer is up to 1.5 mm.  4. The bearing according to claims 1 to 3, characterized in that the metal base is made with a smooth surface.  5. The bearing according to claims 1 to 3, characterized in that the metal base is made with a rough surface.  6. The bearing according to claims 1 to 5, characterized in that the metal base is made of steel.  7. The bearing according to claims 1 to 7, characterized in that a film made of perforated and / or permeable to air is used as the second sliding layer.  8. The bearing according to paragraphs. 1 to 7, characterized in that the second slip layer is made of polytetrafluoroethylene, or polyamide, or polyetherketone (PEEK).  9. The bearing according to claims 1 to 8, characterized in that to enhance and / or improve thermal conductivity and / or wear resistance, the second sliding layer is made with one or more fillers.  10. The bearing according to claim 9, characterized in that fabric, powder or carbon fibers, aluminum oxide, ceramic materials, glass, bronze, molybdenum disulfide or silicon carbide can be used as filler.  11. The bearing according to claims 9 to 10, characterized in that the proportion of filler in the material of the slip layer is 1 40 vol.  12. The bearing of claim 10, characterized in that the proportion of filler in the material of the second sliding layer is 5 to 30 vol.  13. The bearing according to claims 1 to 12, characterized in that the sliding layer made of copolymerizate is made with fillers, which are fabric, powder or carbon fibers, aluminum oxide, ceramic materials, glass, bronze, molybdenum disulfide or silicon carbide .

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