Bellows cylinders are both drive and pneumatic spring components that fall under the category of diaphragm actuators. These pneumatic drives do not have a piston rod. Instead, the simple design consists of two metal plates with ribbed rubber bellows. The high force is generated directly by the pressure on a relatively large surface of the end faces. A return spring is not required, because the return is usually realised by the weight of the applied load. A major advantage of bellows cylinders is the particularly low installation height compared to cylinders and their ease of movement.
This means that larger axis offsets and angular rotations of up to 20° are also possible. And the bellow cylinders are not prone to the stick-slip effect, which is often a problem with conventional cylinders. Double bellows can be used for large strokes.
They can be used with different media, such as compressed air, gas and liquids, as long as the properties of the rubber are taken into account.
Festo bellows cylinders are the right solution for numerous pneumatic actuator applications. They are available with diameters from 80 mm to 385 mm. Strokes of up to 230 mm are possible with these products. The max. carrying force at 8 bar is 70 kN.