What are the advantages and disadvantages of brushless stepper motors and brushed motors?

I. Main Advantages and Disadvantages of Brushless and Brushed Motors:

1. The main advantages of brushless motors are:

First, brushless motors have a long service life: Because brushless motors use a controller instead of a commutator and carbon brushes, their lifespan is several times, or even dozens of times, longer than that of brushed motors. However, the lifespan of carbon brushes is limited; for example, after a thousand hours, the brushes will wear out, requiring either a replacement of the brushes or the motor.

Second, brushless motors have high operating speeds: Brushless motors use magnetic field induction, eliminating physical contact, allowing for faster operation.

Third, brushless motors are quiet: They are primarily suitable for quiet environments, such as hospitals, banks, airports, and schools, where noise reduction is crucial.

Fourth, brushless motors are spark-free: Brushless motors are particularly effective in certain applications, particularly those involving flammable and explosive environments, where they offer increased safety.

2. The main disadvantages of brushless motors are:

First, brushless motors are expensive: The controller adds at least a hundred yuan to the cost of a micromotor. The original commutator and carbon brushes cost much less.

Second, brushless motors have environmental limitations: If a brushless motor is used in a high magnetic field, or has been in contact with or in close proximity to a high magnetic field, it will lose its function. This is primarily because the rotor component of a brushless motor is made of magnets, which are magnetized only after being magnetized. Installing it in or near a high magnetic field will alter the rotor's magnetic field or partially eliminate its magnetism, causing the brushless motor to malfunction or even malfunction.

3. The main advantages of brushed motors are:

First, high control accuracy: Brushed motors are often used with a gearbox and encoder, resulting in higher output power and control accuracy, reaching 0.01 mm, allowing moving parts to stop at virtually any desired position. All precision machine tools use DC motors for control accuracy.
Second, simple structure: Brushed motors have a simple structure, are easy to manufacture, process, maintain, and control. DC motors also offer fast response, high starting torque, and the ability to provide rated torque from zero to rated speed. Third, smooth operation and good starting and braking performance: Brushed motors regulate speed through voltage regulation, resulting in smooth starting and braking, even during constant speed operation. Brushless motors typically use digital frequency conversion, converting AC to DC and then DC to AC, controlling speed through frequency variations. As a result, brushless motors experience uneven starting and braking, with significant vibration, and only operate smoothly at a constant speed.

4. The main disadvantages of brushed motors are:
First, friction between the brushes and commutator causes sparking and significant interference.
Second, due to high resistance, efficiency is low and output power is limited.
Third, maintenance is complex, requiring frequent brush replacement.
Fourth, friction between the brushes and commutator reduces efficiency, increases noise, and generates heat. The lifespan of brushed motors is several times shorter than that of brushless motors.