Slip Rings 101: Contact Styles
A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. Also called a rotary electrical joint, collector or electric swivel, a slip ring can be used in any electromechanical system that requires unrestrained, intermittent or continuous rotation while transmitting power and / or data. It can improve mechanical performance, simplify system operation and eliminate damage-prone wires dangling from movable joints.
Moog Components Group is the world leader in slip ring technology. They produce over 10,000 models in 3 major categories: Through bore style, on-axis capsules and platter form. They can also provide separate brush blocks and rings to be incorporated into customers’ assemblies.
The offering is so broad that we will break this discussion into several Blogs over the next couple months. This month: Contact Styles
Precious metal contacts in the brush block and rings allow for signal speeds compatible with most common data protocols, digital cameras and sensors. Gold, Silver and Nickel are common plating materials for the contacts. Initial contact resistance is as low as 15 milliohms. Typically, this style contact can carry up 10A with rotational speeds up to 600 RPM. Contact life is several million revolutions. Typical applications are security cameras, cable reels and robots.
Fiber Brush Contacts
Fiber brush type contacts provide multiple points of contact for each circuit. The reduced normal-forces at the contact points eliminate material wear, so there is no build up of wear debris. This type of contact is common in higher power and high speed applications. Through bore designs seem to be ideal for this type of contact. They have a very long life, tens of millions of revolutions. This is the highest quality contact on the market, with the highest signal speed capability. Typical applications include emergency lighting, industrial machinery, satellites, unmanned vehicles, antenna systems and wind energy generators.
Silver composite contacts are used on some larger models and are excellent for signal and high power applications. This style is also good for high speed applications, up to 1000 RPM. Typical applications are amusement rides, manufacturing equipment, construction equipment, rotating signage and oilfield equipment.
Moog Components Group is a high quality domestic manufacturer of electomechanical devices including slip rings, motors, resolvers, solenoids, air moving devices, actuators, fiber optic transceivers and multiplexers, fiber optic rotary joints, PC Boards, flexible circuits and higher level assemblies that combine various technologies. For more information visit them at www.moog.com/components