Air cushions
Air cushion ( English air pad are) used, for example, the internal transport large, bulky and sensitive loads. For this purpose, air cushion modules are used that use compressed air to build an air cushion between several pads and the floor. This allows the loads to be shifted with little force.
Air cushion function according to the principle of the hovercraft (hovercraft), d. that is, a relatively small overpressure is created within a flexible rubber seal. On a sufficiently smooth floor surface, only a small part of the air between the floor and the rubber seal can escape. The pressure of the air under the pad allows the load to be moved in a horizontal direction with almost no mechanical friction.
Air cushions are also used on machines when displacements in two directions are required. Here the pads do not have a rubber edge, they are flat, made of metal, slide on a flat metal surface and have holes and channels to distribute the air.
The reverse principle (air through holes in the surface) is used in the game of air hockey .
The read / write heads of hard disks also slide on aerodynamic air cushions that are created by themselves due to the rapid relative movement to the storage medium.