Torsional vibrational dampers (TVD) are one of the important parts in engine system, and it is divided into silicone TVD, rubber TVD and silicone-rubber compound TVD. Most TVD are consisted of hub, inertia ring and damping rubber. These components are installed at the front-end of crankshaft to transfer torque to drive the accessories of wheel system. With the well matching performance, TVD can effectively reduce the crankshaft torsional vibration, improve the durability of crankshaft and reduce the engine vibration and noise.