United Equipment Accessories (UEA) recently received a request for a custom slip ring for a large cable reel used in a mining application. The specifications requested were similar to other designs we have done until we reviewed the requirements for the outer diameter. Typically for a 3 inch bore size and 3-200 amps circuits, we would have an outer diameter of 13.5 inches. This customer, however, was looking for a slip ring to replace an existing slip ring that was failing and needed the slip ring to fit in an existing dimensional envelope of 9.95 inches.
In collaboration with Josh Bockholt, senior slip ring design engineer, we were able to come up with a solution to parallel multiple brushes to condense the outer diameter of the slip ring. With this change, we were able to reduce the diameter of the slip ring by 3.55 inches, an over 25% reduction in the slip ring OD. However, with this tight diameter, the brush bus bar connection was extremely close to the steel housing. A mylar sleeve was added to prevent the slip ring from arcing.
With the technical expertise of our engineering team, we were able to create a 1-off slip ring design to fit exactly what the customer needed. Through our core values of creative problem solving and knowledge seeking, we diligently asked questions to fully understand what the customer needed and develop a custom design for their specific mining application.