ROLLER CHAIN DRIVE SYSTEM HAVING IMPROVED NOISE CHARACTERISTICS

摘要

A unidirectional roller chain sprocket for use primarily in automotive engine chain drive applications which incorporates an asymmetrical tooth for improved noise reduction. The asymmetrical tooth profile incorporates a flank flat which is tangent to an engaging flank radius and a first root radius. The asymmetrical tooth profile also incorporates one or more inclined root surfaces which provide tooth space clearance for maintaining the chain rollers in hard contact with the root surface in the sprocket wrap. The asymmetrical tooth profile further incorporates pitch mismatch wherein the sprocket chordal pitch is less than the chain chordal pitch to facilitate a "staged" roller-tooth contact as a roller moves into full mesh from an initial tangential impact at the flank flat.