The natural graphite is main raw material of this class of brushes. Here, pitch and resin are used binders. They are baked at about 1000℃.
This class of brushes are provided with better lubricating and current- collecting performance. The natural graphite brushes are respectively used with the slip rings of small and medium size DC motor and high speed turbo-generators under steady applications.
This class of brushes consist of various kinds of carbon powders such as carbon black, coke, graphite and so on. They must undergo high temperature treatment at about 2500℃ to make all kinds of carbonic material convert to a micro-crystalline form of artiﬁcial graphite. Hence E1 is electro graphite base, E2 with coke base and E3 with carbon black base.
This class of brushes have excellent characteristic of commutating and self- lubricating, widely applied to all kinds of AC and DC motors with the advantage of long service life and less wear ability of the commutators.
This main raw material used for this class of brushes are electrolytic copper powder and graphite. According to the needs of users,powders of silver, lead and other metals may also be employed.
This class of brushes applicable to low voltage electrical machines with heavy load and ordinary requirements of commutation. Generally, the peripheral speed should not exceed 30 m/s.
This main raw material used for this class of brushes are artificial graphite powder. Pitch and resin are used binders.
This class of brushes applicable to power tools and home appliance.