1.Definition

A permanent magnet stepper motor (PM stepper motor) is a type of stepper motor that uses a permanent magnet as the rotor instead of a traditional wound rotor. This allows for a simpler and more compact design, with high torque and precise motion control.

2.Worrking principle

The basic working principle of a PMSM involves the interaction between the magnetic fields of the stator and rotor. When a current is passed through the windings of the stator, it creates a magnetic field. This magnetic field interacts with the permanent magnetic field of the rotor, causing the rotor to turn, or “step”.

Single Phase Excitation: In this mode, only one phase winding is energized at a time. It results in the least amount of torque and power, but it conserves energy.

Two Phase Excitation: In this mode, two phase windings are energized simultaneously. It offers a higher level of torque and power compared to single-phase excitation.
 

3.Applications

(1)CNC Machines

CNC machines are highly advanced machines used for cutting, drilling, and shaping various types of materials. Permanent magnet stepper motor plays a crucial role in the operations of CNC machines.

Permanent magnet stepper motors move in small steps with high step resolution which results in precise positioning and allows to cutting of the materials in specific designs and shapes. These machines drill holes in materials with precision and repeatability. PM stepper motors offer high torque at low speeds, which helps the motor maintain its position and drill the material in repeated movement.

(2)3D Printers

A 3D printer is a highly advanced printer that has the ability to turn a digital design into physical objects by depositing layers of materials on each other.

The 3-phase stepper motor allows precise control over the movement of the 3D printer for depositing the materials layer by layer and is responsible for creating the intricate design with high accuracy. These motors can be programmed at different speeds and directions and allow printers to create intricate designs and patterns with multiple layers and different colors. 

(3)Medical Equipment

Permanent magnet stepper motors play an important role in various medical equipment such as MRI machines, robotic surgery machines, 

In MRI machines, these motors offer precision and accuracy, which help to position the patient correctly and obtain clear and accurate images of different parts of the body.

(4)Textiles Machines

Permanent magnet stepper motor plays an important in the functioning of textile machines. From spinning to weaving, dyeing, and finishing, these 3-phase stepper motors are used in every stage of manufacturing.

These motors use different stepping modes to move small steps in a controlled manner. This is crucial for textile machines, where even a small error will result in defective products. This ensures that each movement is accurate and results in high-quality products.

4.Advantages

It is compact and small in size, which makes it useful in many applications

Due to the absence of any external excitation, the losses are less and maintenance is less.

It can be connected to the external circuit, to control the speed of the motor

Sensors may be used to locate the rotor winding

Can be operated in a wide range of speed and torque.

Precise Control

Source:https://www.stepperyoyo.com/2024/05/the-applications-and-working-principle.html