Electric machines can be divided into two types according to their purpose: a generator and a DC motor. Remarkably, they are almost the same. The only difference is that the generator converts the mechanical energy of the rotation of the rotor in the magnetic field created by the stator winding into electrical energy, and the motor - vice versa (converts electrical energy into rotational energy, that is, mechanical).
A DC motor has an armature in its design with conductors laid in its grooves. The second main part of this machine is the stator and its multi-pole field windings. The principle of operation of such a device is quite simple. Passing a direct current through the wire of the upper part of the armature in various directions (on the one hand “away from us”, and on the other “on us”). According to the famous left hand rule,those conductors at the top will start to be pushed out of the magnetic field created by the stator to the left, and the conductors located at the bottom of the armature will be repelled to the right.
Since the copper conductors are laid in special grooves, the impact forces will be transmitted to the armature and rotate it.
When one part of the conductor rotates and stands opposite the south pole of the stator, the braking process will begin (the conductor will begin to be pressed to the left side). To prevent this process, it is necessary to change the direction of the current in the wire. For this, a so-called collector is used, and a motor with this principle of operation is called a DC collector motor.
In it, the armature winding will transmit torque to the motor shaft, and that will set in motion the necessary equipment mechanisms. It should be noted that the whole principle of operation of such equipment is based on the inversion of direct current in the anchor circuit.
However, there is also a brushless DC motor. Unlike a collector, it does not have brushes in its device, which create an additional danger during engine operation (brushes rub against a rotating rotor and can create sparks, which can lead to a fire in poorly insulated parts of an electric machine).
A commutatorless DC motor incorporates bearings and special controllers programmed to provideall switching processes inside the motor. In addition, it has micro-motors with high-precision positioning.
That is why such a device will cost significantly more than a conventional DC collector motor. However, the use of such an engine is fully justified: its wear resistance, reliability, and safety have been increased. Both the coefficient of performance (COP) and resistance to overloads are much higher.
Unlike the brushed DC motor, which has actually been discontinued, the brushless model is constantly updated. For example, a non-contact, collectorless, three-phase DC motor has recently been developed.
