What is a PM stepper motor?

 

 

In the realm of motion control, stepper motors play a vital role in achieving precise and controlled movements. Among the various types of stepper motors, the PM (Permanent Magnet) stepper motor stands out as a popular choice. 

 

 

 

 

 

 

 

 

 

 

 

A PM stepper motor is a type of electric motor that converts electrical pulses into discrete mechanical movements. It utilizes a permanent magnet rotor and a stator with multiple coils or windings. The interaction between the magnetic fields generated by the stator and the rotor enables precise and incremental motion.

 

 

 

 

Picture from：42PM48M01-SG50

 

 

 

 

 

 

 

The PM stepper motor operates based on the principle of electromagnetic attraction and repulsion. The stator consists of several sets of windings, typically arranged in pairs, known as phases. Each phase is energized sequentially, generating a magnetic field that interacts with the permanent magnet rotor.

 

When the windings are energized, the rotor aligns itself with the magnetic field, seeking the position of maximum magnetic attraction. By sequentially energizing the windings in a specific sequence, the rotor rotates incrementally, step by step. This discrete motion makes PM stepper motors well-suited for applications requiring precise positioning and control.

 

Advantages of PM Stepper Motors:

Precise Positioning: PM stepper motors offer excellent positional accuracy due to their inherent step-wise motion. They can achieve high-resolution movements, making them suitable for applications that require fine positioning control.

 

Open-Loop Operation: PM stepper motors are often operated in an open-loop system, meaning they do not require feedback for position control. This simplifies the system architecture and reduces costs compared to closed-loop systems.

 

High Torque at Low Speeds: PM stepper motors provide high torque even at low speeds, making them well-suited for applications requiring high holding torque and starting capabilities.

 

Cost-Effective: PM stepper motors are relatively cost-effective compared to other types of motors, making them a popular choice in many industries.