A servo motor is a component of a servo system. It is the engine that controls the operation of mechanical components in a servo system. It is an auxiliary motor with indirect speed change. Its most distinctive feature is that it does not rotate when the signal voltage is zero, and its speed decreases uniformly as the torque increases.
Servo motors enable highly accurate control of system speed and position. They convert voltage signals into torque and speed to drive the controlled object. Servos rely on pulses to determine position and rotate by receiving pulses to achieve displacement. By determining the number of pulses, the rotation angle of the servo motor can be determined, allowing for precise control of motor rotation and accurate positioning.
Servo motors are divided into DC servo motors and AC servo motors. DC servo motors can be further divided into brushed and brushless motors. Brushed motors are lower in cost, simpler in structure, have higher torque, and are easier to control, but they are more inconvenient to maintain, prone to electromagnetic interference, and have higher environmental requirements. Brushless motors, on the other hand, are smaller, lighter, have faster response, smoother rotation, and stable torque. However, their control is more complex, but they are easier to automate, have a longer lifespan, and require no maintenance.
AC servo motors are also brushless motors, and can be divided into synchronous motors and asynchronous motors. Synchronous motors are generally used in motion control because they have a larger power range and inertia, but a lower maximum speed, making them suitable for low-speed, stable applications. The main difference between AC and DC servo motors is that AC motors use sinusoidal wave control, resulting in less torque ripple; while DC servo motors use trapezoidal waves and are cheaper.
