US Patent 7905159 Torsional vibration damper

A torsional vibration damper having a hub carrying a radially projecting flange and an annular inertia mass defining an annular channel encompassing the radially projecting flange and an elastomeric member. An annular compression ring is attached to the opening of the annular channel to axially compress and extrude the elastomeric member to fill the annular channel around the radial flange within the inertia ring. Projections defining an intermittent annular inner rim of the inertia mass extend through openings between the spokes of the hub and cooperate with an annular outer rim of the inertia mass to retain the compression ring.