DC motor is a rotating electric machine capable of converting DC power into mechanical energy (DC motor) or converting mechanical energy into direct current (DC generator). It is able to achieve the DC power and mechanical energy conversion of the motor. When it is a motor motor is a DC motor, the electrical energy into mechanical energy; for the generator is a DC generator, the mechanical energy into electrical energy.
The structure of the DC motor should be composed of two parts: stator and rotor. DC motor running part of the static is called the stator, the main role of the stator is to produce magnetic field, by the base, the main pole, for the pole, the end cap, bearings and brush devices and other components. Rotation of the part called the rotor, its main role is to produce electromagnetic torque and induced electromotive force, is the DC motor energy conversion hub, it is also commonly known as the armature, by the shaft, armature core, armature winding, To the device and the fan and so on.
DC motor inside the fixed ring permanent magnet, the current through the coil on the rotor to produce ammeter, when the rotor on the rotor and the magnetic field parallel, and then continue to turn the direction of the magnetic field will change, so the rotor at the end of the brush with the conversion The sheet is in contact with each other so that the direction of the current on the coil also changes and the direction of the Lorentz force is constant, so that the motor can be rotated in one direction.
The working principle of the DC generator is to convert the armature coil in the alternating electromotive force, by the commutator with the brush of the commutation, so that when the brush from the brush leads to the principle of DC electromotive force.
The direction of the induced electromotive force is determined by the right hand rule (the magnetic induction line points to the palm of the hand, the thumb is pointing to the direction of the conductor movement, and the other four fingers are the direction of the induced electromotive force in the conductor).
The direction of the force of the conductor is determined by the left hand. This pair of electromagnetic forces forms a moment acting on the armature, which is called the electromagnetic torque in the rotating motor, and the direction of the torque is counterclockwise in an attempt to turn the armature counterclockwise. If the electromagnetic torque can overcome the resistance torque on the armature (eg resistance torque caused by friction and other load torque), the armature can be rotated counterclockwise.