.Modelica.Mechanics.Rotational.Components.SpringDamper .Modelica.Mechanics.Rotational.Components.SpringDamperA spring and damper element connected in parallel. The component can be connected either between two inertias/gears to describe the shaft elasticity and damping, or between an inertia/gear and the housing (component Fixed), to describe a coupling of the element with the housing via a spring/damper.
See also the discussion State Selection in the User's Guide of the Rotational library.