A linear motor can be considered as a structural variant of a rotating electrical machine. It can be seen as a rotating electrical machine that is cut along its radial direction and then flattened and evolved. With the rapid development of automatic control technology and microcomputers, higher requirements are placed on the positioning accuracy of various automatic control systems. In this case, the conventional rotary motor is coupled with a linear motion drive composed of a conversion mechanism. Devices are far from meeting the requirements of modern control systems. To this end, many countries around the world are researching, developing and applying linear motors, making the application of linear motors more and more extensive.
Compared with rotating electric machines, linear motors have the following characteristics: First, the structure is simple, because the linear motor does not need to add rotary motion into an additional device for linear motion, so that the structure of the system itself is greatly simplified, and the weight and volume are greatly The ground is lowered; the second is the high positioning accuracy. In places where linear motion is required, the linear motor can realize direct transmission, so that various positioning errors caused by the intermediate links can be eliminated, so the positioning accuracy is high, such as using microcomputer control, Greatly improve the positioning accuracy of the whole system; third, the reaction speed is fast, the sensitivity is high, and the followability is good. The linear motor is easy to support the magnetic levitation of the mover, so that a certain air gap is maintained between the mover and the stator without contact, which eliminates the contact frictional resistance between the stator and the mover, thereby greatly improving the system. Sensitivity, rapidity and follow-up; Fourth, safe and reliable work and long life. The linear motor can realize the contactless transmission force, and the mechanical friction loss is almost zero, so the fault is small and maintenance-free, so the work is safe and reliable, and the service life is long.
Linear motors are mainly used in three aspects: first, they are applied to automatic control systems, and there are many such applications; secondly, they are used as long-term continuous running motor; third, applications require large linear motion in short time and short distance. In the device.
High-speed maglev train Maglev train is the most typical example of the practical application of linear motor. The United States, Britain, Japan, France, Germany, Canada and other countries are developing linear suspension trains, of which Japan has the fastest progress.