Patent ID: 8216101

Claim:
A driving force transmission apparatus comprising: a motion power transmission part configured to transmit a motion power via a driving medium formed by a belt or a chain; a tensioner configured to apply a tension to the driving medium, the tensioner comprising: a compression spring configured to bias the driving medium; a stopper configured to prevent the compression spring from being compressed to less than a predetermined length, wherein the predetermined length is greater than a length of the compression spring at which coils of the compression spring contact each other; and an adjustment part configured to be able to push the compression spring in a direction toward the driving medium to the predetermined length when the tensioner is adjusted, a sliding member configured to support an edge of the compression spring, the sliding member being disposed opposite to the driving medium in the cylinder, and slidably supported by an internal surface of the cylinder, and wherein the sliding member comprises an insertion piece arranged inside the compression spring; and the stopper is configured to prevent the compression spring from being compressed to a length shorter than the predetermined length by abutment with the insertion piece.