Carbon brush for slip ring
Synchronous machine and asynchronous motor all apply the slip ring which is widely used in the branch of industry. And most of them are running in the different kinds of exacting terms.
These kinds of electric motors do not have the commutation action like the DC MOTOR does. But it also brings the carbon brush and slip ring singularity attrition and carbon brush vibration and spark.
From the point of carbon brush grade, slip ring carbon brush not only use the graphite carbon brushes but also use the copper mix carbon brushes to raise the current density. So we have to consider the abnormity after expansion factors. It also can bring the problems even to the turbo generator which is high speed electric machine or to the electric motor which is running in the complete closing gaseous environment or in the hydrogen environment.
Generally speaking, the slip ring carbon brushes which apply the electro graphite grade to use in the synchronous machine which influx low capability direct current and exciting current. We often apply the copper mix carbon brushes to use in the asynchronous machine which have characters like low voltage and high electric current. But the copper mix carbon brushes is inapplicability for those electric motors which have the characters as high peripheral velocity. Besides, the copper mix carbon brushes transit the high electric current which make the carbon brushes and slip rings all wear too much. And at the same time the copper mix carbon brushes also have the malady of thermal expansion.
In addition, the turbo generator which have the character as high peripheral speed must possess especially favorable glide characteristic. We can use the natural graphite carbon brushes which possess good stability and average current distribution.