Torsional vibration dampening device having multiple dampening force levels with transitional dampening means between multiple dampening force levels

摘要

Viscous resistance generation mechanism (71) is a device that dampens torsional vibrations using the restricted flow of a viscous fluid. The mechanism is installed in a flywheel assembly having a first flywheel and a second flywheel coupled to allow for limited relative rotary displacement. The viscous resistance generation mechanism (71) is equipped with a first choke (S1) that generates a resistive force through the passage of a viscous fluid between small chambers formed on either side of the choke (S1) in response to rotary displacement between the flywheels in a first angular displacement range. A second choke (S2) produces a resistive force in a second displacement range greater than the first displacement range, the resistive force of the second choke (S2) being larger than the resistive force produced by the first choke (S1). A transitional damper assembly (50) does not function in the first angular displacement range, but does in the second angular displacement range to lessen the effects of the transition between the resistive force the first choke (S1) and the resistive force of the second choke (S2).