Over the years, Danmar Industries has designed and built thousands of Slip Ring assemblies ranging from economical individual ring and brush assembly to self-contained units complete with seals, bearings, and housings.
How a Slip Ring Works
A Slip Ring assembly is a rotary coupling used to transfer electric current from a stationary unit to a rotating unit. This is accomplished by either holding the center shaft stationary while the brushes and housing rotate around it or by holding the brushes and housing stationary while the center shaft is allowed to rotate.
Slip Ring Material
Slip Ring materials are chosen for their conductivity, wear rates and resistance to oxidation. Rings are made from precious metals, usually coin or fine silver. For some applications, where silver sulphide cannot be tolerated, gold, palladium and platinum alloys or fine silver with a rhodium flash are used instead.
Brush Contact Material
Brush contact materials, used by Danmar Industries, are usually sintered silver graphite. The silver provides the low contact and the graphite provides the lubrication for long wear.
Rotating Speeds
General purpose Slip Ring assemblies are usually limited to slow rotating speeds, not more than 1,000 rpm or less than 1,000 feet/minute. If this speed is exceeded, the assembly is no longer considered a general purpose ring assembly, because special brush material and air cooling may become necessary.