Rotary joints for media

A rotary joint for media transfers hydraulic fluid, air or a vacuum from a stationary connection to a continuously rotating machine part – leakage-free and without torsional limit. It thus closes the gap that occurs when pneumatic or hydraulic supply has to be transferred over a rotating axis: Without a rotary joint, the supply hoses would wind up during rotation and finally tear off – or the direction of rotation would have to be regularly reversed in order to relieve the hoses.

Design and components

The rotary joint consists of a stationary stator with a radial connection and a rotating rotor with an axial connection. The two parts are separated from each other by precision seals that function reliably at high pressures (up to 70 bar). Depending on the variant, more than one media channel can be used concurrently – for applications that need to transfer different media or separate pressure circuits over the same axis of rotation.

Operating principle and use

Rotary joints for media are used wherever rotating machine parts need to be supplied continually with compressed air, a vacuum or hydraulic fluid: in pneumatic grippers and clamping fixtures, in hydraulic drives for special machines, in rotary tables and in machine tools. It is also possible to combine a rotary joint with a slip ring, thus enabling media and electrical signals to be transferred over a single axis of rotation together.