A, the classification of hollow cup motor hollow cup motor is divided into two kinds of brushed and brushless, brushed hollow cup motor rotor without iron core, brushless hollow cup motor stator without iron core. Brush hollow cup is a wire cup plus commutator as the rotor of the motor, brushless hollow cup is a wire cup as the stator, permanent magnet magnet as the rotor structure.
B,Second, the difference between brush motors and brushless motors 1, brush motors brush motors use mechanical commutation, magnetic poles do not move, the coil rotates. When the motor works, the coil and commutator rotate, the magnet and carbon brush do not rotate, the alternating change of coil current direction is done by the commutator and brushes that rotate with the motor. In a brushed motor, this process is done by lining up the two power inputs of each group of coils, in turn, into a ring, separated from each other by insulating material, to form something like a cylinder, connected to the motor shaft. The power supply passes through two small columns made of carbon elements (carbon brushes), under the action of spring pressure, from two specific fixed positions, pressing on two points on the ring-like cylinder of the power input of the coils above, to give a group of coils energized. As the motor rotates, different moments energize different coils or different poles of the same coil, so that the N-S pole of the coil generating magnetic field has a suitable angle difference with the N-S pole of the nearest permanent magnet stator, and the magnetic field opposites attract and same-sex repel, generating force and pushing the motor to rotate. The carbon electrode slides on the coil terminal, like a brush on the surface of an object, hence the name carbon “brush”. Sliding each other, will rub the carbon brush, resulting in loss, need to replace the carbon brush regularly; carbon brushes and coil terminals alternating between on and off, will occur electrical sparks, electromagnetic breakage, interference with electronic equipment. 2, brushless motor brushless motor to take electronic commutation, the coil does not move, magnetic pole rotation. Brushless motor, is the use of a set of electronic equipment, through Hall components, sensing the location of the magnetic poles of permanent magnets, according to this perception, the use of electronic circuits, timely switch the direction of the current in the coil to ensure that the correct direction of magnetic force to drive the motor. The disadvantages of brushed motors are eliminated. These circuits, are the motor controller. The controller of brushless motor can also achieve some functions that brush motor cannot achieve, such as adjusting the power switching angle, braking the motor, reversing the motor, locking the motor, and using the brake signal to stop supplying power to the motor. Nowadays, the electronic alarm lock of electric bicycle makes full use of these functions. Brushless DC motor consists of motor body and driver, which is a typical mechatronic product. Since the brushless DC motor operates in a self-controlled manner, it does not add another starting winding to the rotor like a synchronous motor that starts under heavy load with frequency regulation, nor does it produce oscillations and lost steps when the load changes suddenly.