DE1494079C - Bearing material for plain bearings - Google Patents

Description

1 494 -UY9

There are various storage materials based on plastics with the addition of metal powders already known as a filler. These storage materials can be used as such or applied to metallic materials Support bearings are used. One has already tried; the heat dissipation from bearings to be improved by introducing metal inserts into the heat-insulating plastic materials. ·

As' plastic material for plain bearings have already been The most diverse thermosetting substances, such as phenolic resins, are used .: Hydrocarbon polymers and especially polytetrafluoroethylene are - · because of their good running properties as sliding bearing materials very appreciated.' It was found, however, that the wear and the storage properties of Polytetrafluoräthylerimassen by adding certain Fillers can be further improved.

The invention now provides an improved bearing material for plain bearings based on polytetrafluoroethylene and inorganic fillers; which is shaped by a combination of two fillers from 5 to 40 percent by volume lead and / or lead oxide and 50 to 1 percent by volume copper, copper alloy or copper oxide, the amount of filler Does not exceed 60 percent by volume of the total mass.

In addition to metallic fillers, the plain bearings according to the invention also contain metal oxides, which are known to be poor conductors of heat. These fillers are completely embedded in the plastic material thus do not contribute anything to the dissipation of heat in the sense of the state of the art. It is very surprising that you get extraordinarily durable, wear-resistant by the combination according to the invention Can build storage materials with excellent running properties.

As in the storage materials according to the invention, the metallic fillers can be in the form of powders or fibers. It is expedient to use copper alloys instead of copper, i.e. those that are hardened by the alloying element, such as bronzes and alloys with zinc, aluminum or silicon. An excellent storage material according to the invention is made up of about 60% polytetrafluoroethylene, 10% bronze (90% Cu and 10% Zn) and 30% lead powder. / \

The introduction of the fillers into the plastic happens by kneading in a still plastic state or in the form of a dispersion of the plastic in a Liquid, whereupon the dispersion precipitated and that filled storage material is deformed; The deforming happens in the usual way by pressing, extrusion, Hot pressing_pder casting.

The bearing material according to the invention can be applied to a metal substrate as an actual sliding layer. Since the plastic used according to the invention is a thermosetting material, the curative material will be applied to this metal base as a powder or dispersion, if necessary with a hardener, and then the bearing material forming the sliding layer will be hardened by the action of heat and pressure at the same time. A porous material, which has been obtained, for example, by sintering, can serve as a base. It can be underlaid by a steel girder in the usual way. Such a combined bearing material can serve as a flat bearing, but can also be processed into axle bearings of any known shape.

The invention is illustrated by the following examples:. .

B e i s ρ i e 1 1

50 volume percent polytetrafluoroethylene (density 2.2 g / cm ³ ) + 25 volume percent red lead oxide Pb ₃ O ₄ (d = 9.5 g / cm ³ ) + 25 volume percent copper oxide (d = 6.4 g / cm ³ ) would be in included in the bearing mass. To obtain this bearing material, 4550 g of lead with 320 g of copper at 80 to 100 ° C in iÖOp'cm ³ were a: r, aqueous 15% dispersion of polytetrafluoroethylene stirred. The resulting paste was dried, pressed, aufpulverfein reground and finally formed into the bearing material and is sintered around 360 ⁰ C under a pressure of about 1400 kg / cm ^2.

Example 2

In a manner similar to that of Example 1, a bearing material was produced which consists of 60% polytetrafluoroethylene, 37.5% Pb ₃ O ₄ and 2.5% bronze (89% Cu + 11% Sn, d = 8.9 g / cm ³ ) composed.

The superiority of the storage materials according to the invention is shown using the following tables:

Table I.

Comparative tests of analog bearings with a storage width of 1.27 cm and a diameter of 2.54 cm with a load of 7.26 kg and a running speed of 1290 rpm without water cooling.

Storage material: 60 percent by volume polytetrafluoroethylene with the fillers listed in Table I. The wear is after a running time of 20 hours specified.

lead Bronze ... Wear χ 10 " ^J cm ^J 1.575 40% Lead + Bronze ... 108 3.18 35% Lead + Bronze ... 16.20 30% Lead + , ■ 29.60 20% bronze Table II 40% filler 5% 10% 20%

Comparison on five bearings according to the tests from Table I: Storage material 60 percent by volume Polytetrafluoroethylene; Filler according to composition From the table; Wear and tear after a running time of 64 hours; Load 7.26 kg, running speed 450 rpm, water cooling 25 "C. Bronze: 89% Cu + 11% Sh.

, -,
filler H- 10% bronze Wear χ IO ⁴ cm 30% Pb ₃ O ₃ + H- 5% bronze 33.5 35% Pb ₃ O ₄ H- + 3.1 37 '/ ₂ % Pb ₃ O ₄ 27σ% bronze 1% bronze 1.7 39% Pb ₃ O ₄ 0% bronze 2.5 40% Pb ₁ Ov > KK) ₁ O

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Table III

1.27 cm bearing width in sliding contact with a 2.54 cm diameter shaft; load 7.26 kg. Test conditions similar to the tests in Tables I and II.

Percent by volume polytetrafluoroethylene, filler with component A lead or lead oxide and component B Bronze (89% Cu + 11% Sn), cobalt, nickel, vanadium or chromium.

bronze component Volume percentage wear and tear 4th in χ 10 '* cm ³ 64 component A. Component A B. bronze 16 1.6 Pb ₃ O ₄ 37.5 1.8 bronze PbO 37.5. - hours 2.7 PbO 35.0 - 2.5 cobalt Pb 35.0 - - nickel Pb 30.0 0.8 1 - Vanadium Pb ₃ O ₄ 30.0 0.5 - - chrome Pb ₃ O ₄ 30.0 5.8 1.2 - Pb ₃ O ₄ 30.0 > 100 1.2 - Pb ₃ O ₄ 30.0 14.8 - - Pb ₃ O ₄ 30.0 16.3 - - -

Table IV

Storage mass: 60 percent by volume polytetrafluoroethylene with filler component A lead or lead oxide, component B copper alloy, copper oxide or cobalt; Running speed of the shaft 1350 rpm, working temperature of the shaft 80 ⁰ C, running time 16 hours.

Pb Component B Volume percentage
iComoonente B Wear χ 10 "* 35% 37.5% cm ³ 40% Component A Component A Component A Component A PbO bronze 89% copper 7.3 - - 11% tin Pb ₃ O ₄ bronze 89% copper 11% tin 5.2 Pb ₃ O ₄ bronze 89% copper 5.1 11% tin Pb ₃ O ₄ Silicon bronze 97% copper 5.2 Pb ₃ O ₄ 3% silicon Copper oxide 7.7 7.8 Pb ₃ O ₄ Brass 70% copper 3.9 Pb ₃ O ₄ 30% zinc PbO cobalt > 100 Pb > 100 > 100 > 100

Claims (1)

Claim: Bearing material for plain bearings, consisting of polytetrafluoroethylene and inorganic fillers, characterized by a com combination of two fillers in the form of 5 to 40 percent by volume lead and / or lead oxide and 50 up to 1 percent by volume of copper, copper alloy or copper oxide, the amount of filler being 60 percent by volume does not exceed the total mass.