Patent ID: 8485927

Claim:
A power transmission device comprising: a first pulley having a conical sheave face, a second pulley having a conical sheave face, and a power transmission chain suspended between the first and second pulleys, wherein said power transmission chain includes the power transmission chain comprising: a plurality of links respectively having front and rear insertion parts into which pins are inserted, a plurality of first pins and a plurality of second pins which are arranged in front and back for connecting the links which are arranged in a lateral direction of the chain such that the front insertion part of one of the links is opposed to the rear insertion part of the other link, the first pins and the second pins being relatively moved in rolling contact with each other, whereby the links can be flexed with respect to each other in a longitudinal direction, said power transmission chain being suspended between a pair of pulleys, wherein a plurality of the links includes two types of the links having different pitch lengths, wherein provided that a radius of a pulley shaft is RA, a radius of curvature of a face of the link having a shorter pitch length at an inner diameter side of the chain is RS, and a radius of curvature of a face of the link having a longer pitch length at an inner diameter side of the chain is RL, relation is set to be RA≦RS≦1.5RA, and RS<RL.