Patent ID: 7896767

Claim:
A V-ribbed belt comprising a plurality of V-shaped rubber ribs extending in a longitudinal direction of the belt and arranged in a widthwise direction of the belt, short fibers blended in the rubber ribs, such that part of the short fibers protrude from side faces of the rubber ribs, the protruded short fibers being linear and extending straight from said side faces, wherein a diameter of the short fibers is constant throughout the entire length of said fibers, and the side faces of the rubber ribs from which the short fibers are excluded has an arithmetic average roughness (Ra) between 1 μm and 3 μm, both inclusive, and wherein under a state where the V-ribbed belt is wound between a drive pulley and a driven pulley and is driven by the drive pulley, when the side faces of the rubber ribs slip on a V groove face of the driven pulley in contact with the side faces of the rubber ribs upon non-rotatable fixation of the driven pulley, a number of the protruding parts of the short fibers thermally contract in a lengthwise direction of the short fibers as a result of heat generated at a face where slip occurs such that said protruding parts are buried in the rubber ribs, and a coefficient of dynamic friction increases double or more between the side surfaces of the rubber ribs and the V groove face of the driven pulley, and wherein the short fibers have a melting point in a range between 200° C. and 270° C., both inclusive.