| 摘要 |
A method of incorporating poly-tetra-fluoroethylene into the surface of a bearing element comprises providing the surface with a superposed layer of sintered porous metal or, alternatively, phosphating or anodic etching said surface, degreasing this prepared surface, and then immersing it in an aqueous suspension of poly-tetra-fluoro-ethylene, preferably containing about 55 per cent. solids. The immersion is carried out in a vessel in a vacuum chamber which is alternately exhausted and returned to atmospheric pressure. The element is then removed and dried in a warm current of air at about 50 DEG C. and finally baked at about 350 DEG C. for 2 minutes. Alternatively the poly-tetra-fluoroethylene may be pressed into the pores or crevices at 350 DEG C. Solid lubricant, for example molybdenum disulphide, may be incorporated in the co-operating element of the bearing by first phosphating to produce a receptive surface, degreasing, and then applying a paste consisting of 50 per cent. molybdenum disulphide and 50 per cent. vegetable syrup such as a sugar syrup. The paste is heated to about 80 DEG C. and painted on to the porous metal surface and then heated to a temperature of 300 DEG C. which is maintained for a suitable period. The metal surface is then scraped and the process repeated until a sufficiently thick coating is obtained. Alternatively the molybdenum disulphide may be applied by rubbing into the pores or by applying it in suspension under the action of alternate vacuum and atmospheric pressure.ALSO:A bearing surface incorporating a solid lubricant such as molybdenum disulphide or tungsten disulphide is produced by providing a surface of the metal molybdenum or tungsten, preferably roughened or minutely creviced, and converting the surface of the metal to disulphide by suitable heat treatment in the presence of a sulphiding agent, such as hydrogen sulphide. A suitable porous or creviced surface can be produced by conventional sintering or metal spraying techniques or by phosphating and after sulphiding the surface may be burnished to smooth and densify the surface coating of disulphide. |
