GB1451864A - Friction elements - Google Patents

Abstract

1451864 Carbon elements JURID WERKE GmbH 9 Aug 1974 [9 Aug 1973] 35263/74 Heading C1A [Also in Divisions C4 and F2] A friction element comprises a friction layer, wherein the friction layer has a porous structure and is made of industrial carbon. The entire friction element may be made of industrial carbon or the friction layer may be secured to a support, e.g. a metal plate. The industrial carbon is prepared by freeing cokes, anthracites, carbon black and other forms of carbon from volatile constituents, e.g. by heating at about 1000‹ C. with the exclusion of air. The product is ground and screened and selected granular fractions are compounded into a hot plastic mixture with the addition of molten hard coal tar pitch. This mass is shaped and subjected to a baking process at 1000-1400‹ C. During the baking the articles are embedded in coal dust or grit to protect the material from oxidation and deformation. The uniform baking process extends over several weeks and the ultimate product is "baked carbon". This may be converted to "electrographite" by a further heat treating process using a final temperature of 2700-2800‹ C. These forms of industrial carbon are in the form of plates, bricks, tubes, cylinders, rods or blocks of high pore volume from which the friction layer may be cut or sawn. The friction elements may be used as plates in dry running clutches or oil immersed clutches.