Three-Phase Induction Motor
In comparison to servo motors, three-phase induction motors are characterized by a simpler design and superior operational performance. They are primarily divided into two main components: the stator and the rotor. The stator is the stationary component of the motor, consisting of the supporting frame, stator core, and stator windings. The rotor is the rotating component, composed of the torque transmission element and the rotor support structure.

Servo Motor
Servo motors have a more intricate structure, incorporating not only the stator and rotor but also additional components such as feedback sensors. Typically, the stator core is constructed from laminated silicon steel sheets. The stator slots house two-phase windings, which are arranged perpendicular to each other.

Working Principle
The three-phase induction motor operates on the principle of electromagnetic induction. When three-phase alternating current flows through the stator windings, a rotating magnetic field is generated between the stator and rotor. This rotating field induces a current and electromotive force within the rotor windings. As a result, the current in the rotor conductors interacts with the rotating magnetic field, generating torque and induced voltage within the rotor circuit.
The servo motor, on the other hand, primarily converts the input control voltage into speed and torque, which in turn drives the target mechanism. The key feature of a servo motor is that it does not exhibit self-rotation in the absence of a signal voltage, and its speed decreases in a controlled manner as the torque increases.

Performance and Features
The three-phase induction motor offers excellent operational efficiency, a simple design, light weight, and cost-effectiveness. However, it is limited by challenges such as difficulty in speed control, high inrush current at startup, a tendency to operate beyond its rated capacity, and relatively higher losses during operation.
In contrast, the servo motor provides superior displacement accuracy, excellent positioning precision, a wide speed regulation range, and enhanced system reliability. The most notable advantage of a servo motor is its ability to achieve precise closed-loop control through the use of an encoder, a feature that three-phase induction motors cannot match. However, servo motors come at a significantly higher cost, typically multiple times that of a standard induction motor.

Meca Press Brake equipped with ESTUN servo motor, enabling precise control of speed and flow for adjustable operation. Under the same process conditions, return height, and operator speed, productivity increases by 10% per unit time. Noise levels are reduced by 7dB compared to standard machines. It also cuts energy consumption by up to 50%, with even greater savings during idle periods, such as workpiece repositioning. Additionally, it minimizes heat generation, reducing wear on hydraulic components and extending the machine’s lifespan.