The working principle of carbon brushes for power tools mainly relies on the friction and contact between carbon brushes and brushes (also known as carbon brushes), and realizes the process of converting electrical energy into mechanical energy through the current magnetic field of the coil between the brushes and the electric copper coilCarbon brush motors are mainly composed of a rotor and a stator, the rotor is usually composed of an iron core and a coil, and the stator is composed of a permanent magnetWhen the rotor windings are energized, an electromagnetic field is generated, which interacts with the magnetic field of the stator, resulting in the torsion of the rotor.The coil in the rotor is constantly connected or disconnected from the power supply through the contact between the carbon brush and the brush, so that the AC current is generated in the coil.This alternating current acts through the magnetic field inside the coil and converts electrical energy into mechanical energy, pushing the rotor to rotate.
The role of carbon brushes in the motor is key, it maintains pressure contact with the brushes through springs or other structures to ensure that the current can be transmitted normallyWhen the contact between the brush and the carbon brush is broken, the current stops flowing, the magnetic field in the coil disappears, and the rotor stops rotatingAnd when the contact is restored, the current flows again, the magnetic field is generated again, and the rotor continues to rotateThis working principle of carbon brushes can be simply summarized as "current-magnetic field-force-rotation".
Carbon brushes are usually made of conductive materials such as graphite, which have good conductivity and wear resistance.They are mounted on the stator of the motor and are connected to the motor by a spring or set screw.There are one or more sets of collector rings on the rotor, and the carbon brush establishes a current transfer path with the rotor by contacting these collector ringsThe stability of current conduction depends on the elasticity and wear resistance of the conductive material of the carbon brush, which can ensure good contact with the collector ring and maintain stable current transmissionDue to the contact friction with the collector ring, the carbon brush will gradually wear out, so it needs to be replaced regularly to ensure the reliability of current conduction.
