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Carbon Brush Its Role Is Mainly On The Metal Friction At The Same Time Conductive

Oct 19, 2017


Carbon Brush its role is mainly on the metal friction at the same time conductive; it is not like metal metal friction when the same; metal friction on the metal when the friction; friction may increase; while the transfer of the place may be sintered together; Carbon and metal are two different elements; its use is mostly used in the motor; shape is a variety of; a round and so on.
Carbon Brush for a variety of motors, generators, wheel machine. Has a good commutation performance, long service life. The Carbon Brush is used as a commutator or slip ring for the motor as a sliding contact body for deriving the incoming current. It is conductive, thermally conductive and lubricated well, and has a certain mechanical strength and commutation spark. Almost all motors use Carbon Brushes, which are important components of the motor. Widely used in a variety of AC and DC generators, synchronous motors, battery DC motor, crane motor collector ring, all types of welding machines and so on. With the development of science and technology, the type of motor and the use of working conditions are becoming more and more diversified
Specific role
1. Apply an external current (excitation current) to the rotating rotor (input current) through a Carbon Brush;
2. The static charge on the large axis through the Carbon Brush into the earth (ground Carbon Brush) (output current);
3. The large shaft (ground) to the protection device for the rotor ground protection and measurement of rotor positive and negative ground voltage;
4. Change the current direction (in the commutator motor, the brush also plays a commutation)
In addition to induction AC asynchronous motor no outside. Other motors have, as long as the rotor has a ring to have.
The principle of power generation is the magnetic field after cutting the wires in the wire to produce current. The generator is used to cut the wire by rotating the magnetic field. The rotating magnetic field is the rotor, and the cut wire is the stator.
Carbon Brush, also known as the choice of brush on the motor to suppress the spark has an important role, should be power, voltage, load characteristics and commutator circumference speed and other conditions selected. Commonly used electrochemical graphite brush, because of its high resistance coefficient and contact voltage, to inhibit the spark favorable. However, for low-voltage motors, the large contact voltage makes it a large proportion of the total voltage drop, so the use of metal graphite brush.
A very important basis for determining the quality of Carbon Brushes is the wear rate of Carbon Brushes. The smaller the wear rate of the Carbon Brush, the longer it will be. The same because the Carbon Brush wear rate at a relatively small time, the relevant equipment operation and maintenance personnel will be relatively small workload, operating costs are very low.
1, the smooth surface of the slip ring on the Carbon Brush will cause some wear and tear: If the smooth surface of the slip ring compared to the high, because of the friction coefficient will be relatively small, then the Carbon Brush wear rate can be reduced The In addition we all know that the surface of the slip ring has a layer of oxide film, the main role is to reduce the slip ring and Carbon Brush between the friction coefficient, so as to reduce the degree of Carbon Brush wear.
2, the pressure of the compression spring will also affect the degree of wear of the Carbon Brush: the pressure of the spring must be adjusted moderate, because if the pressure spring pressure is too large, it will increase the mechanical wear of the Carbon Brush; if the pressure spring pressure is too small, Although the friction between the Carbon Brush and the slip ring becomes smaller, it is likely to cause poor contact and sparks.
3, the current will also affect the Carbon Brush wear. Under normal circumstances, the graphite Carbon Brush in the positive Carbon Brush current flow than the negative Carbon Brush current flow is relatively large, casually will cause the positive Carbon Brush wear degree than the negative Carbon Brush wear a little more. And the wear of the positive slip ring is also more than the negative slip ring, then each time the unit overhaul, we can adjust the Carbon Brush by the polarity of the cable head to achieve the purpose of delay wear.