The preload is usually
achieved by the dead weight of the object to be stored.
Jörn GmbH has been supplying bearings for decoupling vehicle cabins for decades. Here Mr. Reinke presents some variants and goes into the technology. The spectrum ranges from very light cabins to heavy duty applications. Among others, Jörn supplies his mounts to Daimler, MAN and Fendt. But also special vehicles of all kinds are equipped with Jörn bearings, such as fire engines.
Have fun!