Today's concept of servo motor is much broader than in the past, and the products contained are also very rich, whether it is DC, AC, synchronous, asynchronous, brush, brushless, all of these types have servo motors.
Brush and brushless are only for how to deal with the commutation device of the rotor. They can be DC and AC motors, or synchronous and asynchronous motors.
But we often say that there is a Brush Motor generally refers to a DC motor.
The Brush Motor has the disadvantages of carbon brush wear and commutation to generate electric spark, but the commutation is stable and the torque pulsation is small. Therefore, in some occasions, the Brush Motor still has advantages, but generally in applications with low current. DC servo is relatively simple and cheap.
AC servo is sine wave control with small torque pulsation. AC servo has a tendency to replace DC.
Servo motors are generally synchronous motors. Compared with asynchronous motors, synchronous motors have higher efficiency and smaller volume.
Induction motors are generally tightly combined with asynchronous motors.
Motors below 5KW are generally not induction motors, but brushless and synchronous permanent magnet motors.
As far as the righteousness is concerned, according to the industry's general understanding, the servo motor we usually mention generally refers to AC, synchronous, brushless, permanent magnet motor.
At present, the maximum power of servo motor provided by Danaher transmission can reach 15KW, but products below 5KW are widely used.
According to the different types of servo motors selected by the user, the matching drivers are basically different, which mainly depends on the difference between the commutation mode and the control algorithm, such as the commutation waveform of the brushed motor and the brushless motor, the control algorithm of synchronous motor and asynchronous motor is also different.