The role of carbon brush in hand drill?
The role of carbon brushes in motors:1. the external current (excitation current) is added to the rotor by carbon brush (input current)2., the static charge on the big shaft is introduced into the earth (carbon brush) through the carbon brush (output current)3. lead the main shaft (ground) to the protection device for rotor ground protection and measure the positive and negative voltage of the rotor4. change the direction of the current (in the commutator motor brush, also plays a role reversal)The commutator consists of brush and commutator ring, and carbon brush is one of the brushes. Because of the rotation of the rotor, the brush is always rubbed with the reversing ring, and the spark will be burned at the instant of commutation, so the brush is a vulnerable part in the direct current motor.In order to improve the service life and stability of the DC motor and reduce the noise and electromagnetic interference of the DC motor, brushless DC motor has gradually replaced the trend of brush motor.General AC motors do not use constant magnetic field, so there is no need to commutator, and no brush, but the volume of AC motor is generally relatively large. The use of household electrical appliances are generally AC motor, such as electric fans, washing machine, refrigerator, air conditioning and so there is no carbon brush, but also the use of DC motor, such as electric shaver, many small kitchen appliances, such as electric bicycles have a carbon brush, is DC motor (not including brushless) have. The motors that use dry cells are all DC motors.
In order for the rotor to produce a magnetic field, the magnetic current must be input into the coil of the rotor. The carbon brush is used to send the heavy magnetic current into the rotor coil by the magneto generator.There is only carbon brush in the motor with only the commutator or slip ring, and the common AC asynchronous motor is a squirrel cage structure without carbon brush. The motor is the abbreviation of the motor, that is, the motor. The motor can be divided into DC motor and AC motor, DC motor due to the rotation of the rotor, and the need to constantly switch according to current coil position changes in the magnetic field in the direction of the coil, so the need for a DC motor commutator.
After cutting a wire through a magnetic field, an electric current is generated in the wire. The generator cuts the wires by rotating the magnetic field. A rotating magnetic field is a rotor, and the wire to be cut is a stator.
To understand the role of carbon brushes, you first need to understand the basic principles of electric energy and kinetic energy conversion, that is, to understand the principles of the motor. Principles of power generation.
