Pot bearings support the vertical load through a rubber disc confined within a steel pot and a steel lid. The rubber disc is subject to a tri-axial compression and behaves like an incompressible fluid, thus being very effective in transmitting the vertical loads without deflection. At the same time, it allows rotations around any axis thanks to its deformability.
Horizontal loads are transferred through the contact between the pot and the lid.
Horizontal displacements (for free sliding and guide bearings) are permitted with a very low friction coefficient through sliding surfaces composed of a sheet of PTFE mated with an austenitic steel surface greased with silicon grease.
They are suitable to transfer both very high vertical and horizontal loads.
The mark utilized to identify the pot bearings considers the loads and movements at Ultimate Limit State (ULS)