DE1400949A1 - Plain bearings or bearing material - Google Patents

Description

DR. ING. F ^

Ϊ. G. PtTLiS SCHWEIÖERSTHAürax. «,

TKI-IFON 2806 91 DR. IWG. D. BEHRENS teleobammadbessb:

MUNICH

P l * l 00 9 ^ 9.5

1400949 Mf ^ f ₁₉₆₈

Description of the patent application

BBA GROUP LIMITED
Cleckheaton, Yorkshire, England

concerning
Plain bearings or bearing material

There are already known methods for producing plain bearings from a porous base material and impregnating this porous material with a polytetrafluoroethylene dispersion. For sufficient storage stability, however, the proportion of polytetrafluoroethylene can only be small, practically only the surface layer. Attempts have also been made to paint sliding surfaces off. a mixed dispersion of polytetrafluoroethylene and a resin or in a mixture with a resin solution. Here, the dispersion size of the polytetrafluoroethylene is about 1 m and the layer thickness is 2.5 to 38, u. In many cases, however, this layer material does not correspond, namely with regard to the adhesion to the base material and the dissipation of frictional heat. It was

809809/0137

(Art. 7, Paragraph 1, Paragraph 2, No. 1 Sdtz 3 the Amendment Act.

a stock material has already been produced, including a Fiber material and a resin were used; the fiber material was asbestos or cotton, it was covered with polyethylene. Instead of this embodiment, a Wiping cloth made of polyethylene and asbestos or cotton can be used. In terms of production technology, polyethylene offers no difficulties. In terms of running properties, polyethylene is only moderately suitable Plastic. According to an older proposal, a bearing material made of an epoxy resin and polytetrafluoroethylene was already made manufactured.

The Erfinlu-. £; now enters a plain bearing or a 3> .germaterial for the production of plain bearings from a Combination of polytetrafluoroethylene with a resin; it is characterized in that polytetrafluoroethylene is incorporated in fibrous matted form in the resin. The production of the slide bearing according to the invention or Storage material is done in such a way that one is a mixture of a resin and a granular polytetrafluoroethylene in a still viscous state at a temperature below the sintering temperature of the polytetrafluoroethylene subjected to a pressure and shear treatment, so that the granular polytetrafluoroethylene becomes a fibrous felted Mass arises'. The whole thing is then molded and the resin cured in the usual way. The resin can be a water- or alcohol-soluble cresol formaldehyde or Phenol-formaldehyde condensation product, a polyurethane or use a vulcanizable rubber.

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It is well known that polytetrafluoroethylene is relatively difficult to process. It is insoluble and infusible and can be therefore also not in the sense of the above known method Apply to a polyethylene thread material. Also, it cannot be turned into one, or only under extreme conditions Process thread material by extrusion and subsequent sintering, so that this option is also practical is impracticable

It is known that the runnability of polytetrafluoroethylene with slide bearings is particularly favorable, so that one is possessed, a bearing material with a considerable Anteix to produce polytetrafluoroethylene. Impregnation e.g. of a porous bronze with a polytetrafluoroethylene dispersion does not produce the desired results.

When constructing the bearing materials according to the invention for the production of "the plain bearings, a resin must be used, which is suitably thermosetting, has sufficient strength and abrasion resistance, good adhesion on the base or the support material and in the uncured state in a mixture with polytetrafluoroethylene and optionally other fillers has such a viscosity that the granular polytetrafluoroethylene below the pressure and shear loads into the fibrous form

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leads can be. A metal or Molybdenum sulfide can be used. You can also use it in the usual Way introduce a reinforcement material.

The storage material according to the invention can be directly as a plain bearing, i.e. without a support sphale or the like, but it is also possible to use it in a bearing shell.or incorporate a support shell. This is useful in all cases where there is only one sliding layer on a mechanical one fixed construction element is desired. The support material or the like. Can be made of any conventional, any Material, e.g. a metal material or plastic of appropriate strength and rigidity, where the Plastic can optionally be reinforced. However, it is also possible to use a flexible carrier web - e.g. made of rubber or a synthetic rubber - to be provided with the plain bearing material according to the invention »

■ To produce the bearings according to the invention, a coagulated dispersion of polytetrafluoroethylene is used after drying and mixing with the resin, considerable compressive and shear forces below the sintering temperature subjected to polytetrafluoroethylene. However, it is also possible to mix the two products among those mentioned To apply pressure and shear loads. This fibrous Mass is then according to the intended use

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processed e.g.

1. Shapes into foils or sheets under pressure and heat (e.g. 150 C 5 to 30 min per material thickness / under one Molding pressure of about 0.8 to 1.6 kg / mm) 2 · Working through on a roller frame with one of these Slot width so that a film with a thickness of 0.0127 to 0.127 mm is obtained. This slide can then be used on a Support material can be applied as a sliding layer, namely:

a) A strip of aluminum alloy or steel, sandge- · radiates and degreased, was dissolved in 5 min at 15O ⁰ C under a pressure of about 0.8 kg / mm coated. The tapes can be pretreated with a heat-resistant adhesive to improve adhesion

b) They can with a fabric-reinforced laminate link by being laminated directly to one or more layers of pre-impregnated and dried fabric, followed by about 0.8 to 1.6 kg / mm and a temperature of from 1 40 to 16O ⁰ C is pressed in 5 to 30 minutes depending on the strength. The curing of the phenolic resin within the fabric-reinforced laminate and the sliding layer can take place in the same process step, see above;

that there is an intimate connection of the whole layer material achieved. ,

3 * This fibrous material can also be used e.g. with the help of a vibrating chute on the surface of a prepreg

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ned reinforcement fabric, which can be preheated if necessary, »pour the whole thing through a Guide calender. This laminate can now be applied to metal strips apply as mentioned above or process it into a layer material mentioned above. However, it is too possible to produce an endless band of hardened bearing material in that the mass is continuously heated and is rolled, e.g. when passing through a progressive heating zone.

example 1

45 parts by volume of water-soluble phenol-formaldehyde resin (25 56 solids content) were added to a mixer with 3 arms provided with 10 parts by volume of graphite powder, then 10 parts by volume of lead powder were introduced and finally 35 parts by volume of polytetrafluoroethylene introduced · The mass was squeezed off on a 3.175 mm sieve so that a dry, fibrous product emerged, which depending on the processed further for the intended purpose »

Example 2

100 parts by weight of liquid polyurethane with 9 to 10 $> isocyanate groups were ^{degassed at 10O 0} C and 5 mm Hg then ^{cooled to 80 0} and 25 parts by weight of 4,4'-methylene (2-chloraniiine) -melted at 100 to 105 ⁰ C -

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mixed in quickly and thoroughly. The whole thing was poured into a cup, cooled to room temperature and worked through in a rubber mill with: 40 vol .- $ polytetrafluoroethylene. Die.dabei films formed were min at 100 ⁰ C in 15 and at a pressure of about 8 to 16 kg / mm formed and a further 45 min ⁰ C maintained at 1Op "

Claims

809809/0 137

Claims (8)

Pat. üche 1. Plain bearings and bearing material made from a mixture of polytetrafluoroethylene and a resin, characterized in that polytetrafluoroethylene in fibrous gef'ilzter Mold is incorporated in the resin with the exception of an epoxy resin. 2. A method for producing the bearing or storage material according to claim 1, characterized gekennzei chnet that one introduces a resin granules of polytetrafluoroethylene and in a still viscous state at a temperature below the sintering temperature of the polytetrafluoroethylene to form the fibrous matted form, the mixture of a Subjects to pressure and shear treatment, the mass forms and the resin hardens. · 3. The method according to claim 2, characterized in that g e k e η η - draws that the resin is a water- or alcohol-soluble cresol-formaldehyde, phenol-formaldehyde condensation product, a polyurethane or a vulcanizable one. Rubber used. 8179 8 0 9 8 0 9/0137 New documents fArt7 stAh _a ο ^ & · BATH ORIGINAL