Basic structure/working principle/advantages/application areas of linear motors

Linear motors are electromagnetic devices that convert electrical energy directly into linear motion energy. Their structure has evolved from traditional cylindrical rotary motors, and their working principles are similar to those of rotary motors. Imagine cutting a rotary motor radially and unfolding the motor's circumference into a straight line, and you get the original linear motor. The stator and mover in the original rotary motor have evolved into the primary and secondary in the linear motor, respectively. The radial, circumferential, and axial directions in the rotary motor are called normal, longitudinal, and transverse directions in the linear motor.

01Basic structure and working principle of linear motor

When current is passed through the primary winding of the linear motor, a sinusoidally distributed air gap magnetic field is generated in the longitudinal direction. When the three-phase current changes with time, the air gap magnetic field will move in a straight line according to the phase sequence of the alternating current. This translational magnetic field is called a traveling wave magnetic field. The secondary conductor generates an electromotive force and forms a directional induced current under the cutting of the traveling wave magnetic field. The induced current and magnetic field in the secondary generate a longitudinal electromagnetic thrust under the joint action of the secondary. If the primary is fixed, the secondary will move in a straight line along the direction of the traveling wave magnetic field. This is the basic principle of the linear motor.

02Advantages of Motor Module

1. There is no mechanical contact, the transmission force is generated in the air gap, and there is no other friction except the linear motor guide;

2. Simple structure and small size, we can realize our linear drive with the least number of parts, and there is only one moving part;

3. Theoretically, the running stroke is not restricted, and its performance will not be affected by changes in the stroke size;

4. Its operation can provide a wide range of speed, ranging from a few microns to several meters per second, which is a prominent advantage especially at high speeds;

5. The acceleration is very large, and the standard load is 1G acceleration;

6. The movement is smooth because there are no other mechanical connections or conversion devices except the linear guide or air bearing for support;

7. High accuracy and repeatability, because the intermediate links that affect the accuracy are eliminated. The accuracy of the system depends on the position detection element, and with a suitable feedback device, it can reach sub-micron level;

8. Simple maintenance, due to the small number of parts and no mechanical contact during movement, which greatly reduces the wear of parts, requires little or no maintenance, and has a longer service life. Performance comparison table of linear motor and "rotary motor, ball screw" transmission performance rotary motor + ball screw linear motor.

03Application fields of linear motor modules

1.In industry and automation-because linear motors have their own unique advantages;

2. In the transportation industry - linear motor technology is an important application in maglev trains;

3. Application in material conveying and handling-linear motors have unique advantages in various material conveying and handling;

4. Application in civil and construction industries - Linear motors are also widely used in civil and construction industries;

5. Application of linear motors in the field of computers and office equipment In computer optical drive devices.