Torsional vibration damping apparatus

In an apparatus for damping vibrations, particularly between an engine and a power train, wherein a first flywheel is connectable with the engine, a second flywheel is rotatable relative to the first flywheel and is connectable with the power train, particularly by way of a clutch, and damper means operates between and yieldably opposes rotation of the flywheels relative to each other, the improvement which resides in the provision of at least three of the following features:

• (a) one of said flywheels includes sections defining an annular compartment for a supply of viscous fluid medium, particularly a medium of pasty consistency, which at least partially fills the compartment, the compartment has an at least substantially closed cross-sectional outline and said damper means comprises at least two energy storing elements, such as springs, which are disposed in said compartment at the same distance from the axis of said one flywheel and are engaged by said sections;
• (b) a flange extends radially into said compartment and engages said elements and at least substantially seals said compartment, and means is provided to transmit torque between said flange and the other of said flywheels;
• (c) the flywheels are rotatable relative to each other against the opposition of said elements through at least 25 degrees in clockwise and counter-clockwise directions starting from a neutral position;
• (d) the total number of said elements is less than five and said elements jointly extend along an arc which approximates between 70 and 96% of a complete circle;
• (e) said elements jointly extend along 70-96% of the circumference of said one flywheel;
• and
• (f) said elements are prefabricated to exhibit a curvature with a radius of curvature which equals or approximates the radius of said annular compartment.