Generally speaking, slip rings have good wear resistance and high mechanical strength, so they are mainly used in synchronous motors with large slip rings due to polarity. Steel can be machined into complex structures and is a readily available and inexpensive material widely used in hydroelectric generators and low peripheral speed synchronous motors. Forged steel is sometimes used for slip rings where mechanical strength and wear resistance at high speeds are primarily emphasized, such as turbine generators. In addition, stainless steel can be used when corrosion resistance is required, but the sliding performance of stainless steel is unstable. If it is not combined with the brush, the brush may bounce, resulting in excessive temperature rise or abnormal phenomena. The brush wears out, so you need to use it two or more times. The copper slip ring made of bronze casting has superior sliding performance and wider range of use than steel slip rings, but when it contains a large amount of low melting point lead, the lead will be removed by heating. The collector ring of the energization point is worn or the brush is abnormally worn.

Regarding the cooperation between the collector ring and the brush, when the brush wear is too large and the material of the collector ring is too soft, the collector ring tends to have step wear equal to the width of the brush. In particular, a fully enclosed motor with high temperature and low humidity is more likely to cause excessive wear of the brushes or collector rings. This is how ghost scars form, leaving only a small scar at first, but the current in this area is not well concentrated, causing the brush to spark. Once sparking occurs, the scar gradually deteriorates and enlarges, forming a scar the size of the brush sliding contact surface. Therefore, care needs to be taken even if the slip ring brush produces a small spark.

To avoid serious ghost marks on the collector rings, the brushes should be lifted with the motor stopped for a long time. The active point of the slip contact surface of the slip ring can be moved to change the current distribution of the shunt brushes. In order to obtain good sliding performance, it is effective to open the spiral chute on the slip ring.