Camshaft damper

Claim 1

A drive sprocket for an internal combustion engine camshaft comprising, in combination, a circular body having a hub region, an outer periphery and an axis of rotation, means defined in said hub region for attaching said body to the end of the camshaft in torsion-transmitting relationship, radial extending drive surfaces defined on said body periphery for meshing with a flexible tension-transmitting member, a cylindrical surface homogeneously defined on said body concentric to said axis, an annular ring of synthetic elastomeric material mounted upon said cylindrical surface, and an annular inertia ring mounted upon said elastomeric material, said inertia ring including an inner cylindrical surface, said elastomeric material being bonded to said compressed between said cylindrical surfaces of said sprocket body and said inertia ring, said sprocket body cylindrical surface, elastomeric material and said inertia ring comprising torsional vibration damping means directly mounted upon said body and integral with said body for damping torsional vibrations about said body axis, said sprocket including a web radially extending between said hub region and said outer periphery, said inertia ring, body cylindrical surface and elastomeric material being located adjacent to and in axial alignment with said web, and an oil passage defined in said sprocket hub region extending from said hub region to adjacent said body outer periphery along said web for lubricating said tension transmitting member.