Rodless cylinders contain the movement produced within the overall length of the cylinder body, this means that they are able to support load during the movement, unlike piston rod cylinders. They can also be called rodless actuators and the term ‘rodless slide’ is sometimes used.
A piston moves within a cylinder bore, driven by compressed air, very much like a conventional profile or tie-rod cylinder; the difference is that motion is transmitted to outside through the body length, rather than by a piston rod through an end cap.
A ‘strut’ connects the piston to a table which runs on guides along the length of the cylinder. Air pressure is maintained by a sealing strip which ‘breaks’ around the strut, as the table moves, then re-seals. Clearly, the sealing strip also maintains sealing around the strut to reduce leakage to an acceptable level. The IMI Norgren Lintra seal gives extremely low static leakage values when in use.
Rodless cylinders need to be connected into the system, so fittings and tubing are essential. As a component, the correct filtration and pressure regulation will be important. Although not essential, slots in the extrusion allow use of the IMI Norgren M/50 series switches and grooves accept industry-standard aluminium machine building systems.