This information is part of the Modelica Standard Library maintained by the Modelica Association.

This is a 1-dim. rotational component with one flange and a support/housing. It is used e.g., to build up parts of a drive train graphically consisting of several components.

If useSupport=true, the support connector is conditionally enabled and needs to be connected.
If useSupport=false, the support connector is conditionally disabled and instead the component is internally fixed to ground.