Inverted tooth chain and sprocket drive system with reduced meshing impact

Abstract

An inverted tooth chain drive system defines a meshing contact angle Tau (τ) between the tangent line TL and an initial contact reference line that passes through a controlling pin center and the initial contact location. A link plate entrance angle Beta (β) is defined between the initial contact reference line and an inside flank reference line that passes through an arc center of the inside flank radius and the initial contact location. A meshing impact angle Sigma (σ) is defined between the tangent line and the inside flank reference line such that σ=τ+β, wherein β≦9° and σ≦34°. The pressure angle of the sprocket tooth can be adjusted and the chain optimized such that β≦7° and σ≦31°. The system thus provides a reduction of the link impact force Fand the resultant impact energy E. The inverted tooth chain, itself, defines a pitch P and an inside flank projection Lamda (λ) such that 0.007×P≦λ≦0.017×P when said chain is pulled straight. The outside flanks include a chamfer to ensure that initial contact between the chain and sprocket is always on the leading inside flanks of the chain.