On linear motor
Linear Motor is a kind of transmission device that directly converts electric energy into mechanical energy for linear motion by expanding closed magnetic field into open magnetic field without any intermediate conversion mechanism.
Structure of linear motor
The structure of a linear motor can be regarded as that a rotating motor is cut along the radial direction and the circumferential surface of the motor is unfolded into a straight line. The stator of rotary motor is equivalent to the primary of linear motor, and the rotor of rotary motor is equivalent to the secondary of linear motor. When the current is applied to the primary stage, the traveling wave magnetic field is generated in the air gap between the primary stages, and the driving force is generated under the action of the traveling wave magnetic field and the secondary permanent magnet, thus realizing the linear motion of the moving parts.
Advantages of linear motor
1, high-speed response
Because some mechanical transmission parts (such as screw) with large response time constant are not used in the system, the dynamic response performance of the whole closed-loop control system is greatly improved, and the response is extremely sensitive and fast.
2, high precision
The linear drive system cancels the transmission error caused by mechanical mechanism such as lead screw, and reduces the tracking error caused by the lag of transmission system during interpolation. Through the feedback control of linear position detection, the positioning accuracy can be greatly improved.
3. High dynamic stiffness
Because it is directly driven, it avoids the motion lag phenomenon caused by elastic deformation, friction and wear and reverse clearance of the intermediate transmission link during starting, variable and reversing, thus improving its transmission stiffness.
4. Fast speed and short acceleration and deceleration process
Because there is no influence of inertia and resistance moment of the intermediate transmission mechanism, the acceleration and deceleration time of the motor is short, and it can realize rapid start and positive direction operation.
5, the stroke length is not limited.
The requirement of extending the stroke length can be achieved by connecting a linear motor in series on the guide rail.
6, quiet exercise, low noise
Because the transmission screw and other parts are eliminated in the structure, there is no mechanical friction, and the guide rail can adopt rolling guide rail or magnetic pad suspension guide rail, so the noise during its movement is greatly reduced.
Application of linear motor
Linear motor is widely used because of its high speed, high acceleration, high precision and unlimited stroke. Main applications of linear motor:
First, it is used in automatic control systems, and there are many such applications;
Secondly, as a driving motor for long-term continuous movement;
Third, it is used in devices that need huge linear motion energy of the whole system in a short time and a short distance.
