Abstract: A torsional vibration damper in which variable volume chambers pump oil through restricted passages in response to relative torsional movement between a driven and inertia member in the damper. The passages are connected to radially inner and outer sides of an annular spring. Torsional oscillation causes the spring to deflect in a circumferential direction and the restricted passages damp the vibration.

Abstract: A torsional vibration damper of the type that incorporates a plurality of radially extending springs in chambers containing damping fluid. The springs flexibly connect an inner hub with an annular outer component comprised of two rings fastened in abutting relation. Opposed recesses in the rings form spring receiving chambers. The outer ends of the springs are clamped either by shims or spring seating wedges acting against the side walls of the recesses, thus eliminating the need for a peripheral clamping ring holding the springs in clamped relation.