Linear Synchronous Motor

Stator (also known as primary)

It is usually a fixed rectangular component with three-phase windings distributed on its surface (similar to the stator winding of a rotating synchronous motor). When an alternating current is applied, it generates a traveling wave magnetic field (a magnetic field that moves along the length direction of the stator).

Primary/Stator:

Usually, it is an armature winding that generates a traveling wave magnetic field or pulsating magnetic field when AC power is applied.

The winding form can be divided into:

Distributed winding (similar to the deployment of a rotating motor).

Centralized winding (simplified manufacturing, but with significant thrust fluctuations).

Rotor (also known as secondary)

It is a movable part whose core is a permanent magnet array (or superconducting magnet, excitation winding) that generates a constant magnetic field. When the traveling wave magnetic field of the stator moves, the magnetic field of the rotor interacts with the traveling wave magnetic field (repulsion of the same polarity, attraction of the opposite polarity), generating synchronous electromagnetic force, which drives the rotor to move synchronously with the magnetic field.

Key feature: The motion speed of the rotor is strictly synchronized with the speed of the stator traveling magnetic field (synchronization speed=magnetic field movement speed), hence the name "synchronization".

Secondary/Mover:

Secondary permanent magnet: composed of alternating arrangement of permanent magnets (such as neodymium iron boron), with high magnetic field strength and efficiency (commonly used in precision applications).

Induction plate secondary: composed of magnetic conductive materials (such as iron core) or conductive plates (aluminum/copper), with low cost but low efficiency (similar to linear induction motors).

Support and guidance system

Linear guide rails, air bearing or magnetic levitation ensure smooth motion of the rotor.

Position sensor (optional)

Grating ruler, magnetic grating ruler or Hall sensor, used for closed-loop control.

Type

Core driving principle

Speed/accuracy

Cost

Typical scenario

Linear synchronous motor (LSM)

Synchronous action of traveling wave magnetic field and permanent magnet

High speed (>10m/s), high precision (micrometer level)

High

Maglev train, precision machine tool

Linear Asynchronous Motor (LIM)

Induced Eddy Current Force in Conductive Secondary by Traveling Wave Magnetic Field

Medium to High Speed, Medium Precision

Low

Conveyor Belt, Elevator

Linear direct current motor (LDM)

Interaction between permanent magnet magnetic field and armature current

Low speed, medium precision

Small

Medium-sized automation equipment

1

Rail Transit and High Speed Transportation

Maglev train

This is one of the most representative applications of LSM. For example, Shanghai Maglev trains and Japan Superconducting Maglev (L0 series) generate traveling magnetic fields through stators (long stator windings laid on the track), which interact with the magnetic fields of the moving elements (permanent magnet arrays) at the bottom of the train, directly generating linear thrust and achieving train suspension (without wheel rail contact). Its speed can reach over 400km/h, and it runs smoothly with low noise.

Urban Rail Transit Auxiliary System

Partial subway or light rail sections, as well as airport rapid transit systems, utilize LSM to achieve short distance high-speed traction and improve transportation efficiency.

2

Precision manufacturing and high-end machine tools

High speed precision machining equipment

In scenarios such as semiconductor wafer cutting, optical component processing, and precision mold manufacturing, LSM is used to drive machine tool workbenches or cutting tools, achieving micro - or even nano level positioning accuracy and high acceleration (such as 10g or more), meeting the requirements of high-precision and high-speed processing.

Electronic manufacturing industry

The wire bonding platform of chip packaging equipment and the mobile mechanism of PCB board inspection equipment rely on the fast response and positioning accuracy of LSM to improve production efficiency and product yield.

Logistics and Automated Sorting

High speed sorting system

In e-commerce warehousing and express distribution centers, LSM driven independent sliders can move at high speeds along the track (up to 5m/s or more), achieving rapid sorting of goods (such as processing tens of thousands of packages per hour) by precisely controlling the start stop and turning of each slider.

3

Intelligent warehousing and handling

In the automated three-dimensional warehouse, the horizontal/vertical drive mechanism of the stacker crane adopts LSM to reduce mechanical transmission clearance, improve the speed and positioning accuracy of goods storage and retrieval.

4

Aerospace and Simulation Testing

Flight/Aerospace Simulator

The LSM driven linear motion platform is used to simulate dynamic scenarios such as acceleration, diving, and weightlessness of aircraft. It can provide high thrust and fast response (in milliseconds), reproducing real flight conditions.

Wind tunnel test auxiliary equipment

In the aerodynamic performance testing of aircraft, LSM controls the linear motion trajectory of the model to accurately simulate the airflow effects at different speeds.

5

Medical and high-end equipment

Medical imaging equipment

The bed drive mechanism for magnetic resonance imaging (MRI) and CT scanning uses LSM to achieve millimeter level precise positioning of patients and reduce scanning errors; The radiation source mobile system of radiotherapy equipment ensures high-precision control of the radiation irradiation position through LSM.

Rehabilitation equipment

The limb traction mechanism of high-end rehabilitation robots utilizes the smooth thrust and precise speed control of LSM to assist patients in gait training and other rehabilitation movements.

6

Research and Special Equipment

Materials Science Experiment

LSM can provide stable loading force and precise displacement control for material tensile/compression testing equipment under high temperature and high pressure environments, and obtain material mechanical performance data.

Particle Accelerator

The particle beam linear acceleration section of some accelerators uses the electromagnetic structure of LSM principle to control the motion trajectory and velocity of particles.