Torsion damping assembly

Claim 1

In an assembly adapted for connection between input and output drives of a torque transmitting driveline, the assembly including torsional energy isolating means and damping means disposed in parallel connection, the isolating means operative when connected between the input and output drives to transmit driveline torque between the drives and allow limited relative rotation of the drives in response to torsionals in the driveline torque, the improvement comprising: a viscous coupling defining the torsional energy damping means, said coupling including a rotatably mounted housing member defining a chamber containing a viscous fluid and a second rotatably mounted member having a portion disposed in the chamber for viscous clutching coaction with the housing, said housing member and second member respectively connectable with one of the drives and operative to dampen said torsionals by the viscous clutching coaction in response to the isolating means allowing relative rotation of the drives said rotatably mounted housing member disposed for rotation about an axis and connectable at its outer periphery to one of the driveline drives, said housing member including first and second sidewalls extending radially outward of said axis to define said chamber, said first sidewall having a closed central portion extending across said axis, said second sidewall having open central portion allowing connection a said second member to the other drive of the driveline, and said chamber sealed against leakage by a dynamic seal sealingly interposed between said second rotatably mounted member and said second sidewall, whereby said chamber is sealed by a single dynamic seal.