What is Slip Ring?
A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. A slip ring can be used in any electromechanical system that requires rotation while transmitting power or signals. It can improve mechanical performance, simplify system operation and eliminate damage-prone wires dangling from movable joints. They can be used on any rotating object to transfer power, control circuits, or analog or digital signals including data such as those found on aerodrome beacons, rotating tanks, power shovels.
How does a Slip Ring work?
The slip rings consist of two main components; metal ring and brush contact. According to the application and design of the machine, the number of rings and brushes are decided.
Depending on the RPM (rotations per minute), the brushes are fixed with rotating rings, or rings are rotating with fixed brushes. In both of these arrangements, the brushes maintain contact with the ring by pressure from the springs.
Generally, rings are mounted on the rotor and it is rotating. And brushes are fixed and mounted on the brush house. The rings are made up of conductive metal like brass and silver. It is mounted shaft but insulated with a center shaft. The rings are insulated from each other by nylon or plastic.
As the rings rotate, the electrical current is conducted through the brushes. Therefore, it makes a continuous connection between the rings (rotating system) and brushes (fixed system).
Types of Slip Rings
Through Hole Slip Rings
Through hole slip ring has a hole in the center of the slip ring. It is used in devices where requires to transmit power or signal when need 360˚ rotating. This type of slip rings is designed to install with a flange on a sleeve bracket. It has free space in the center for connecting the shaft of a machine without affecting cable while it is rotating.
It has a long life span and offers low noise and maintenance. This type of slip ring is used for routing hydraulic pneumatic passages and it can integrate with high-frequency joints.
Pneumatic Rotary Union
A rotary union is a union that allows for rotation of the united parts. It is thus a device that provides a seal between a stationary supply passage (such as pipe or tubing) and a rotating part (such as a drum, cylinder, or spindle) to permit the flow of a fluid into and/or out of the rotating part. Fluids typically used with rotary joints and rotating unions include various heat transfer media and fluid power media such as steam, water, thermal oil, hydraulic fluid, and coolants.
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