Considerations for Mounting Slip Rings to Hydraulic Swivels

Hydraulic swivels, also known as hydraulic rotary manifolds, are precision components designed to transfer fluid from a stationary source to a rotating piece of machinery. A slip ring and hydraulic swivel cohesively designed together as a single assembly improves economies of scale and reduces the number of components, suppliers, and the potential for component failure.

The picture below shows Hydraulic swivels&slip ring used for argriculture industry:

The presence of oil or water within a slip ring enclosure can lead to everything from slight discoloring of one or two components to complete failure of the slip ring assembly. We would suggest the slip ring assembly be located in a place away from oil and water as much as possible, along with sealing the slip ring enclosure as tightly as possible.

Positioning the slip ring below the hydraulic swivel means the center leads or harness from the slip ring must pass up through a center hole in the hydraulic swivel. Unless the center hole of the hydraulic swivel can be sealed at the top of the swivel, using either a liquid-tight style connector or flexible conduit around the center leads, any rain, oil, etc. can pass down through the hydraulic swivel and directly into the slip ring. 

To avoid a potential column of water or oil in the center hole of the hydraulic swivel, spacers are often added between the bottom of the hydraulic swivel and the mounting flange of the center tube of the slip ring to allow drainage of the center hole.

Another important factor­, whether mounted above or below the hydraulic swivel, is to provide adequate drainage from the bottom of the slip ring.  The sophistication of the drain required will depend upon the operating environment and the possibility that the slip ring will be sprayed from below with either road spray or high pressure cleaning spray.  Allowing the slip ring to have air exchange or 'breath' through the drain also helps to prevent condensation from forming inside the enclosure.

Put simply, for slip rings in an outdoor industrial environment and independent of the mounting orientation, the assembly needs to be sealed as well as possible from the top and drained at the bottom. 

Depending on customer and application requirements, ByTune can provide slip rings and as an integrated unit, semi-integrated or as two separate units for Hydraulic Swivels. Slip rings of BTH series can be used to mount the slip ring on a bracket or used for routing space for hydraulics. Multi-contacting can ensure contacting reliable with low wear.