The hollow cup motor and the brush motor are two widely used drive motors. Which one is better? The advantages and disadvantages of the hollow cup motor and the brush motor are described in detail below.

Advantages of hollow cup motor:

1. High power density: Power density is the ratio of output power to weight or volume. The copper coil type motor is small in size and good in performance. Compared with the traditional coil, the induction coil of the copper plate coil method is lighter. There is no need for winding and slotted silicon steel sheets, which eliminates the eddy current and hysteresis losses generated by them; the eddy current loss of the copper plate coil method is small and easy to control, which improves the efficiency of the motor and ensures higher output torque and output power.

2. High efficiency: The high efficiency of the motor lies in the fact that the copper plate coil method has no eddy current and hysteresis losses caused by winding and slotted silicon steel sheets; in addition, the resistance is small, which reduces the copper loss.

3. No torque lag: The copper plate coil method has no slotted silicon steel sheet, no hysteresis loss, and no cogging effect, which reduces the speed and torque fluctuations.

4. No cogging effect: The copper plate coil method has no slotted silicon steel sheet, which eliminates the cogging effect of the interaction between the slot and the magnet, the coil is a structure without an iron core, and all the steel parts either rotate together (for example, a brushless motor ), or all stand still (for example, with a brushed motor), cogging and torque hysteresis are clearly absent.

5. Low starting torque: no hysteresis loss, no cogging, and low starting torque. At start-up, usually the bearing load is the only obstacle. In this way, the starting wind speed of the wind turbine can be very low.

6. There is no radial force between the rotor and the stator: Since there is no static silicon steel sheet, there is no radial magnetic force between the rotor and the stator. This is especially important in critical applications. Because the radial force between the rotor and the stator will cause the rotor to become unstable. Reducing radial forces will improve rotor stability.

7. The speed curve is smooth and the noise is low: the silicon steel sheet without grooves reduces the harmonics of torque and voltage. At the same time, since there is no AC field in the motor, there is no AC noise. Only noise from bearings and airflow and vibration from non-sinusoidal currents.

8. High-speed brushless coil: When running at high speed, it is necessary to have a small inductance value. A small inductance value results in a low start-up voltage. By increasing the number of poles and reducing the thickness of the case, the smaller inductance value helps reduce the weight of the motor. At the same time, the power density is increased.

9. Quick response brushed coil: The brushed motor of the copper plate coil method has a fast response to the voltage fluctuation due to the low induction value. The moment of inertia of the rotor is small, and the response speed of torque and current is equivalent. Therefore, the rotor acceleration is twice that of a conventional motor.

Disadvantages of the hollow cup motor: When the DC motor is in a static state, if one phase of the winding is cut off or one phase of the power supply is cut off and the power is turned on, the magnetic field points generated by the windings are equal in size and opposite in direction. The size is equal, the direction is opposite to cancel each other, and the zero starting torque motor cannot be started, which is the disadvantage of the hollow cup gear motor. The disadvantage of the hollow cup gear motor is a very dangerous fault. First, we need to check whether the DC motor is faulty, check whether there is a circuit breaker in the power circuit, whether there is a fuse, and then check whether there is a current interruption in each phase of the three-phase winding. .

Advantages of brushed motor: simple structure, simple structure of brushed motor, easy production and processing, convenient maintenance and easy control; DC motor also has fast response, large starting torque, and can provide rated torque from zero speed to rated speed. performance. Stable operation, good starting and braking effect. The brushed motor is adjusted by voltage and speed, so the starting and braking are stable, and it is also stable when running at a constant speed. Brushless motors are usually digital frequency conversion control, which first converts AC into DC, then DC into AC, and controls the speed through frequency changes, so the brushless motor runs unevenly during starting and braking, and the vibration is large, only when the speed is constant. will be stable. High control precision, brushed motors are usually used together with gearboxes and decoders, so that the output power of the motor is larger and the control precision is higher. The control precision can reach 0.01 mm, which can almost make the moving parts stop at any desired position. place. All precision machine tools are controlled by DC motors for precision.

Disadvantages of brushed motors: There is friction between the brushes and the commutator, resulting in reduced efficiency, increased noise, and easy heat generation. The life of brushed motors is several times shorter than that of brushless motors. Maintenance is cumbersome and requires constant brush replacement. Because of the large resistance, the efficiency is low and the output power is small. The friction between the brushes and the commutator will cause sparks and cause great disturbance.