Principle and Application of Linear Motor
time£º2010/4/1 click£º8698
Principle and Application of Linear Motor
With the improvement of linear motor technology, the application of linear motor has become more and more extensive, but there is very little information on the market, so that many people do not understand linear motor. This kind of motor can be considered as a kind of deformation of the structure of the rotating motor. It can be seen as a rotating motor that is cut along its radial direction and then flattened.
Compared with rotary Motors, linear Motors mainly have the following characteristics:
(I) Simple structure:
Since the linear motor does not need to convert the rotation into an additional device for linear motion, the structure of the system itself is greatly simplified, and the weight and volume are greatly reduced;
(II) High positioning accuracy:
Where a linear motion is required, the linear motor can achieve direct transmission, thus eliminating various positioning errors caused by the middle link. Therefore, the positioning accuracy is high. If microcomputer control is used, the positioning accuracy of the entire system can be greatly improved.;
Third, the reaction speed is high, the sensitivity is high, the pace is good.
It is easy for the linear motor to use magnetic levitation support for its movers, so that the air gap between the movers and the stator is always maintained without contact. This eliminates the friction resistance between the fixed and the movers, thus greatly improving the system's sensitivity, rapidity, and Activiousness;
(IV) Reliable work and long life span.
The linear motor can achieve no contact transmission force, and the mechanical friction loss is almost zero, so there are fewer faults and no maintenance, so the work is reliable and the life is long.
Linear motors are mainly used in three aspects:
First, it is applied to automatic control systems. There are many occasions for such applications;
2) as a driving motor for long-term continuous operation;
Iii) For devices that require a short time and a short distance to provide huge linear motion energy.
-- The maglev train of high-speed maglev trains is a typical example of the practical application of linear Motors. At present, the United States, Britain, Japan, France, Germany, and Canada are all developing linear suspension trains. Among them, Japan is making rapid progress.
The elevator driven by linear Motors The elevator driven by linear motors in the world was installed in the Wanshi Building in Shimashima, Tokyo, Japan, in April 1990. The elevator has a load of 600kg and a speed of 105m/min, raising the height to 22.9 M. Because there is no tracer unit for a linear motor driven elevator, the computer room at the top of the building can be omitted. If the height of the building increases to about 1,000 meters, it is necessary to use a steel-free rope elevator. This elevator is driven by a linear motor with high temperature superconductivity technology. The coil is installed in the shaft and the car is equipped with a high-performance permanent magnet material. Like a maglev train, Use radio waves or optical control technology to control.
When an ultra-high speed motor rotates beyond a certain peak, motors with rolling bearings will produce sintering and damage. For this reason, in recent years, a linear suspension motor(electromagnetic bearing) has been developed abroad. The suspension technology has been used to levitate the motor's movers in the air, eliminating the mechanical contact and friction resistance between the movers and the stators, and its speed can reach 25,000 to 1000000 r/min. Therefore, it has been widely used in high-speed motors and high-speed spindle components. For example, the 5-axis controllable electromagnetic high-speed spindle for multi-process automatic numerical control lathes recently developed by Aikawa Corporation of Japan adopts two radial electromagnetic bearings and one axial thrust electromagnetic bearing, which can withstand the load of the machine tool on Renyifangxiang. In the middle of the shaft, in addition to the high-speed motor, it is also equipped with a tool automatic exchange mechanism suitable for multi-process automatic numerical control lathes.
We have reason to believe that linear motors will inject new power into the development of our industry. (Information source from network)
Linear motor