Silent chain

Abstract

A silent chain is provided which has reduced elongation based on wear and which is capable of maintaining a high accuracy over a long period of time in use. The inner surfaces of pin holes formed in at least joint trains of plates have been subjected to shaving, and a hard layer of at least one hard metal carbide selected from a group including CrC, TiC, VC and NbC, is formed on the surface of each pin. By shaving the inner surface of each pin hole, the surface pressure applied between the pin hole inner surface and the pin inserted therein becomes lower, whereby the wear of the pin and the pin hole is diminished. Further, since the hard layer on the pin surface is very hard and is chemically stable, the affinity of each plate for the inner surface of each pin hole formed therein is small. Thus, even under the condition of boundary lubrication, it is difficult for adhesion to occur between the pin hole inner surface and the pin inserted therein. Consequently, the amount of pin wear is lessened so that it becomes possible to minimize the elongation of the chain based on wear.

Dependencies are inferred from the claim text.