Custom Electrical Slip Rings & Their Application

Posted on Friday, April 6, 2012 in UEA Blog

An electrical slip ring assembly is required to be mounted on the center of rotation between the stationary and rotating components of a piece of equipment. Often there are other fluids or possibly other types of signals that need to pass between the stationary and rotating components and these too require some type of rotary joint. In all cases of more than one type of rotary joint mounted on the center of rotation either the slip ring wiring must pass through the center of the other unit, such as a hydraulic rotary swivel or union, or the hydraulic lines must pass through the center of the slip ring.

With designs for up to 14.00” through-bore, UEA slip rings can be built to meet a high percentage of the combination rotary union applications. Usually when combined with a hydraulic swivel, since the slip ring wires or leads bundle are much smaller than hydraulic hoses, it makes more sense economically to pass the electrical leads through the center of the hydraulic union. In these cases the center bore size, and therefore the overall diameter of the slip ring assembly can be minimized and the cost of the slip ring portion of the overall assembly also minimized. There are other applications that require one or more air passages in addition to the electrical and hydraulic swivel unions. Depending upon the size or sizes of air lines required, UEA has designed and used a combination of purchased single passage or UEA
custom designed two and four passage rotary pneumatic swivel units. The UEA pneumatic swivel units feature all brass construction and two or four 1/8” NPT ports for control-type air lines. Note that these same all brass swivel units have also been used with other gases and fluids, normally only requiring a different material seal between the passages. When combined with a UEA slip ring center harness both the wiring harness and the air swivel lines pass through the center hole of the hydraulic swivel. With this design the pneumatic swivel unit is removable without the necessity to disrupt or remove either the slip ring or the hydraulic swivel unit. A very similar design has been used to combine a fiber optic rotary
joint (FORJ) with a UEA slip ring.

As a custom slip ring manufacturer UEA has in the past and continues to design a variety
of 'combination' units to meet center of rotation rotary needs.

-Brent Jensen, Head Engineer