| 摘要 |
<p>1,201,772. Brake linings; friction clutches. BORG-WARNER CORP. 21 Aug., 1967 [25 Oct., 1966], No. 38362/67. Headings F2C and F2E. [Also in Division C7] In a friction element, such as for clutches and brakes, having a rigid backing member 10 and at least one friction member 12a affixed to the backing member, the friction member has a porous layer of metal fibres heat treated to sinter adjacent fibres directly to one another and the porosity of the layer is at least 50% voids. The fibre material may be of carbon steel, chrome or molybdenum alloy steels, stainless steel, Cu, or steel fibres with a diffused coating of Cr or Mo followed by carburizing. The fibres are slurried in a liquid, felted on a disc former, dried and compressed. Two discs of fibres are then assembled on each side of a steel backing plate 10 and the assembly is compressed and sintered in a reducing atmosphere such as hydrogen. One representative process of forming the sintered layer is described in Specification 821,690. As shown, the friction discs are formed with outer sintered fibre metal layers 16 having less voids than the inner layers 14 so that if the friction discs are operated in oil the inner layers 14 absorb more oil than the outer layers to provide good frictional properties at the wear faces. The friction members may be used in a vehicle automatic transmission and multiple disc clutch pack. The backing plate 10 may be of bronze, steel or cast iron and may be attached to the friction members 12a by welding, sintering, brazing or by cementing with phenolic or epoxy resin. The wear faces of the friction members may be hardened at their outer surfaces (20, Fig. 3, not shown), by nitriding, carburizing, applying a hard facing or applying a glassy enamel ceramic-like coating to the fibres. The enamel coating is applied to the sintered metal fibres in the form of a slurry and the friction members are then heated in an oven to melt the enamel into the interstices care being taken not to seal off the entire surface of the wear face so as to enable oil to be absorbed into the porous layers beneath the enamel coating.</p> |
