The brush is made of precious metal alloy and is "II" shaped with symmetrical double contact with the groove of the conductive ring. The elastic pressure of the brush is in sliding contact with the groove of the conductive ring to transmit signals and current. .
Collection rings are also called conductor rings, slip rings, collector rings, bus rings, etc. It can be used in any electromechanical system requiring continuous rotation while transmitting power and signals from a fixed position to a rotating position. Slip rings can improve system performance, simplify the system structure, and prevent wires from being strained during rotation.
Slip ring synchronous motors and asynchronous motors using slip rings are widely used in industrial sectors and most of them operate in dvarious difficult conditions. Although these motors do not have the switching function of DC motors, like commutators, they also suffer from abnormal wear of commutator rings or brushes, brush vibration, and spark generation. Especially from the perspective of brush material, not only graphite brushes are used for slip ring brushes, but also metal graphite brushes are sometimes used to increase the current density of the brush. Therefore, factors such as abnormal residual expansion must also be considered. Even for high-speed engines such as turbogenerators or engines operating in fully enclosed gas and hydrogen media, many problems arise.
The collector ring material requires high mechanical strength, good electrical conductor and corrosion resistance. LorIf it is in sliding contact with the brush, it must have stable wear resistance and sliding contact characteristics. Generally, steel slip rings have good wear resistance and high mechanical strength, so they are mainly used in synchronous motors where the slip ring wear difference is large due to polarity.
The factors that cause fires in the collector ring of the generator are:
1. The quality of carbon brushes is poor. Carbon brushes break easily if overheated. causes the carbon brushes to come into contact with the collector. An arc between the collector rings;
2. Hydrogen leaking from the generator sealing tile near the collector ring;
3. The collector ring cooling air inlet is blocked, causing drafts. The quantity is reduced, which affects the refr effectcoldening of the collector ring surface;
4. The generator seal oil is leaking and the carbon powder is not discharged. smoothly, and the mixture of oil, gas and carbon powder contaminates the collector ring chamber;
< p>5. Poor contact between the carbon brush and the commutator ring surface, overheating of the commutator ring surface and carbon brush assembly, etc. Among them, poor contact between the carbon brush and the slip ring is the main reason for the fire accident of the slip ring. Poor contact between the carbon brushes and the commutator ring causes local sparking, causing an increase in the temperature of the commutator ring, deterioration of carbon brush contact, and uneven distribution of excitation current between the brushes coal, resulting in a ring fire. Poor contact between the carbon brush and the surface of the collect ringeur is generally difficult to detect, causing collector ring fires that last relatively short time and are therefore difficult to treat in time.