How Air Cushions Work


How Air Cushions Work

Air cushions are a sort of fluid cushion that uses compressed air as the lubrication medium. They generate a thin film of air of approx. 0.01 mm on which the load almost floats, allowing it to be moved freely and turned in any direction. The coefficient of friction on smooth surfaces is only μ=0.001, which means that only 10 N of force is required to move a load of 1,000 kg.

Because the air cushions are hinged, they can compensate for slight undulations in the floor. At least 3 air cushions are required for a sturdy arrangement. The air cushions also execute a short stroke (approx. 10-80 mm) that depends on the diameter of the cushion.

Optimal operation requires a working pressure of just 1 – 2 bar. If there is little space available, it is recommended that 4 bar air cushions are installed. They have the same dimensions but double the load-bearing capacity of 2 bar types.


floor requirements

The use of air cushions presupposes that the floor is smooth and level. In addition, the ground must be stable and airtight. Joints, cracks and gaps must be sealed before driving over them. Poor quality floors can be made temporarily passable with the use of floor mats or metal sheets.

We would be happy to advise you on the floor requirements or help you find an experienced specialist for floors and coatings.

Data Sheet: Floor requirements

Data Sheet: Floor mats


working principle of air cushions

Step 1

In the idle position the load rests on the floor.

Step 2


When the air cushion is charged with compressed air, the ring-shaped rubber bellows inflates, sealing the interior from the floor. There, a pressure chamber forms, raising the load.

Step 3


As soon as the air pressure in the chamber exceeds the counterpressure of the load, some air escapes into the surroundings of the bellows to form a thin film of air that causes the load to float. The load can now be moved almost without friction in any direction.


Technical data

Sizes: Ø 150 – 1,400 mm (6" - 55")
Load capacities: 150 – 60,000 kg (330 - 132,000 lb)
Lifting heights: approx. 10 – 80 mm (3/8" - 3")
Operating pressure: max.2 or 4  bar (35 or 70 psi)

- with integrated support plate

- Explosion protected

- Wear protection coating

- Clean room version