The difference between linear induction motor, linear DC motor, linear synchronous motor and linear stepper motor?
time£º2017/9/6 click£º13333
The linear induction motor is a unilateral excitation motor. The structure is very simple, so it is applied early and widely in the medium-low speed rail transit system. The common linear induction motor is a single stator structure. In order to improve the magnetic path, a bilateral stator linear induction motor can also be used. The linear induction motor is characterized by unilateral excitation. Generally, the movers use induction plates(solid, windless), with a simple structure and economy.
The coil of the linear DC motor can move freely along the shaft of the iron bar. Within the range of the coil, the magnet gives it a roughly uniform magnetic field B. When the DC power source I is introduced into the coil, the part of the conductor coil in the magnetic field will be affected by the electromagnetic force. The direction of this electromagnetic force can be determined by the electromagnetic induction left-handed rule. The left palm is facing the B direction, and the four fingertips follow the current direction. The direction of the thumb is the direction in which the coil is affected by the electromagnetic force. Therefore, it can be easily judged that as long as the direction of DC current I is changed, the direction in which the coil is forced can be changed, and the direction in which the coil moves can be changed.
Compared with the linear DC motor and the linear AC motor, the obvious advantages are: high operating efficiency, no low power factor; The control is convenient and flexible. The linear DC motor and the closed-loop control system are combined to control the displacement accurately. The speed and acceleration control range is wide, and the smoothness of the speed regulation is good.
The linear synchronous motor is the same as the corresponding rotating synchronous motor in principle. Like ordinary synchronous Motors, it has a multiphase armature winding and a DC excitation magnetic field. The excitation method of the DC magnetic field can be conventional, it can also be excited by Superconductor excitation winding, and it can also use permanent magnets. Although in principle, a linear synchronous motor can be mobile as an armature or a magnetic field, it seems that the latter type is more practical. One of the advantages of linear synchronous Motors is that the power factor is good and the efficiency is high, so it is more suitable for air gap and high-power Motors.
The permanent magnet linear motor is also a type of linear synchronous motor, but its rotor is no longer magnetically excited, but uses a permanent magnetic pole. The advantages of permanent magnet linear motor are unilateral excitation and high magnetic density, so the volume is small and high efficiency. However, because the permanent magnet is not as easy to adjust the flux as the electromagnetic, the weak magnetic control performance of the permanent magnet linear motor is poor. Moreover, permanent magnetic materials are more expensive and therefore more suitable for shorter orbits or closed environments, such as missiles or extension launchers, and are less used in vehicles. In recent years, due to the small size and high control accuracy, cylindrical linear permanent magnet motors have more and more applications in servo systems, especially where CNC equipment requires high precision positioning. Basically, permanent magnet AC linear synchronous motors are used.
A linear stepper motor, or linear stepper motor, is a magnetic rotor core that generates rotation by interacting with a pulse electromagnetic field generated by the stator. The linear stepper motor converts rotation into linear motion within the motor. Application: The linear stepper motor is widely used in many high-precision fields including manufacturing, precision calibration, precision fluid measurement, and accurate position movement.
Linear motor