Abstract: The invention relates to a highly tear propagation-resistant rubber compound, particularly for sealing and expansion bellows, containing an elastomer, fillers and other auxiliaries. In order to achieve high tear-propagation resistance with high imperviousness, dynamic stress resistance and chemical resistance, a rubber compound is proposed which contains polychloroprene as the elastomer and amorphous silica as the filler, and which is obtained by silanising in the presence of the acid acceptor and the silica, prior to adding other additives.

Abstract: Torsional vibration dampers for piston engines, particularly for motor vehicle engines, are mounted on the crankshaft of the engine in a torsionally resistant manner. The hub (2) bears a first flyring (3) which concentrically surrounds the hub and is connected to the outer surface of the hub (2) via a rubber spring device (5) acting in the peripheral direction. Furthermore, a second flyring is provided which is secured to the hub (2) via a rubber spring device (8), again acting in the peripheral direction. To allow a torsional vibration damper of this kind to damp all vibrations generated by the engine using simple means, the rubber spring device (5) bearing the first flyring (3) is rigid while the rubber spring device (8) of the second flyring (4), which is located radially outside the first flyring (3), is flexible.