Servo motor is a high-precision and high response actuator, whose core function is to accurately, quickly, and stably convert control signals (usually electrical signals) into mechanical motion (such as position, speed, or torque), and achieve real-time closed-loop control to meet the stringent requirements of complex automation systems for dynamic performance and positioning accuracy.
Its unique value and core role are mainly reflected in the following aspects:
Accurate position control:
Core competency: This is the most prominent role of servo motors. It can receive position commands (such as pulse signals, analog voltages, or bus commands) and detect the actual position of the motor shaft in real time through built-in encoders and other position feedback devices.
Closed loop regulation: The controller (driver) continuously compares the commanded position with the actual position and calculates the error signal.
Accurate execution: The driver precisely adjusts the current (i.e. torque) output to the motor based on the error signal, drives the motor to rotate to eliminate errors, and ultimately makes the motor shaft accurately stay at the required position of the command, with an accuracy of up to arcseconds or even higher.
Application examples: joint positioning of industrial robots, tool feed of CNC machine tools, worktable movement of precision measuring instruments, nozzle positioning of 3D printers, component picking and placement of surface mount machines.
Accurate speed control:
Stable speed regulation: Servo motors can achieve extremely smooth and precise speed regulation within the range of zero speed to rated speed or even higher speed according to speed commands.
Anti disturbance: Even if the load changes (such as changes in the weight of objects on the conveyor belt), the servo system can quickly adjust the output torque through closed-loop feedback (encoder feedback speed information), maintain the stability of the set speed, and avoid speed fluctuations.
Quick response: It can respond very quickly to changes in speed commands, achieving rapid acceleration or deceleration.
Application examples: constant line speed winding of textile machinery, register synchronization of printing machines, variable speed operation of conveyor belts on assembly lines, precise speed control of centrifuges.
Stable torque control:
Accurate output: The servo motor can receive and accurately execute torque (torque) commands, outputting constant or on-demand torque.
Force control application: In scenarios where precise control of applied force is required (such as screwing, constant tension unwinding, and force feedback in precision assembly), the servo system achieves precise force management through torque control mode combined with position/velocity feedback.
Overload protection: The driver can limit the maximum output torque of the motor, protecting the mechanical structure from damage.
Application examples: constant tension control of winding machines, flexible assembly of robotic arms, force loading of material testing machines, torque control of electric screwdrivers.
Excellent dynamic response performance:
Fast start stop and reversing: Servo motors have extremely high response speed and very low moment of inertia (especially low-power motors), which can complete start stop, acceleration, deceleration or reverse rotation in a very short time (milliseconds).
High speed followability: The ability to closely follow rapidly changing command signals is crucial for situations that require high-speed, high-frequency reciprocating motion.
Application examples: high-speed labeling machine, electronic component insertion machine, mirror drive for laser cutting machine, high-speed sorting system.
Summarize its core role:
A servo motor is not just a simple "rotating" device, it is an intelligent, precise, and fast responsive motion execution unit. Its core function is to convert control commands (position, speed, torque) into highly controllable, accurate, and responsive mechanical motion outputs under the drive of a closed-loop control system, and to have strong anti-interference ability to adapt to load changes. This ability is the cornerstone of modern high-precision, high-efficiency, and highly flexible automation equipment and intelligent manufacturing systems.
In short, the function of a servo motor is to execute motion commands accurately, quickly, and stably. It is a key power element for achieving intelligent execution capabilities of automation equipment, such as "hitting where you want", "fast as you want", "slow as you want", and "as much force as you want".