The conductivity of brush slip ring is very essential to the performance of the equipment and the stability signal transmission. Brush is a conductive part for sliding contact with moving parts. Can be used to the commutator or slip rings, as import and export current sliding contact body. Its conductivity, good thermal conductivity and lubricity, and has a certain mechanical strength. Almost all of the DC motor and commutated motors use brushes, it is an important component of the machine.

The first generation of slip ring is carbon brush structure, since the carbon easy to wear, in use, the case of rotational friction and to high temperatures, high temperatures can easily lead to carbon oxidation, wear and oxidation two deadly factors determine the life of carbon brushes slip ring is the shortest, and therefore, we can see that now basically no one uses a carbon brush slip ring.

The selection of the brush plays an important role when motor commutation sparks inhibition, should be selected according to power, voltage, load characteristics, circumferential speed of the commutator. Commonly used electric graphite brush, its resistivity and contact voltage higher favorable to suppress sparks. But for low-voltage motors, metal-graphite brushes can be done.

Due to the drawbacks of the carbon brush slip ring, so researchers will develop a second generation of brushes slip ring, such slip ring brushes structure to avoid the many drawbacks, such as easy to wear, easy to oxidation. Due to the progress of modern technology, the brush slip ring technology is more advanced, in previous, only using copper brush and copper ring to transmit signal and power, since copper is relatively soft, if the rotational speed was high or long time used, it is easily deformed, affecting close contact, thus resulting in distortion of current and signal transmission. Behind the development of precious metal brush and copper ring to solve this problem, such as adding trace elements of alloy conductive material, rare earth, rare metals, a good solution to this problem. Now, brush slip ring is still the main choice for low cost slip ring. Many of manufacturers are using brush slip ring, especially equipment price is not high, the number of very large companies, due to cost reasons, brush slip ring is still their first choice.

The history of the slip ring can be seen more and more mature technology products, technology updates faster, product availability and product effectiveness is also growing stronger! Applications and prospects of brush slip ring is also very large.