The servo motor used in the automatic screen printing machine is also called the executive motor or the control motor. In the automatic control system, the servo motor of the electric screen printing machine is an actuator. Its function is to convert the signal (control voltage or phase) into mechanical displacement, that is, to convert the received electrical signal into a certain speed or angle of the motor. Displacement.
Its capacity is generally 0.1-100W, and commonly used is below 30W. The servo motors of automatic screen printing machines are divided into DC and AC. At present, AC and DC motors are used in screen printing machines, and DC servo motors are the most used.
AC servo motor used in automatic screen printing machine. The structure of the AC servo motor's stator is basically similar to that of the capacitor split-phase single-phase asynchronous motor. The stator is equipped with two windings with a position difference of 90°. One is the field winding Rf, which is directly on the AC voltage Uf; the other is the field winding Rf. It is the control winding L, which is connected to the control signal voltage Uc. Therefore, the AC servo motor used in Haoda screen printing machine is also called dual motor.
The rotor of the AC servo motor used in the automatic screen printing machine is usually made into a squirrel cage, but in order to make the servo motor have a wide speed range, linear mechanical characteristics, no "rotation" phenomenon and fast response performance, it is compatible with Compared with ordinary motors, it should have the two characteristics of large rotor resistance and small moment of inertia. At present, there are two ways to construct rotors that are widely used: one is a squirrel-cage rotor made of high-resistivity conductive materials with high-resistivity conductive materials. In order to reduce the moment of inertia of the rotor, the rotor is made slender; the other is One is the hollow cup-shaped rotor made of aluminum alloy. The cup wall is very thin, only 0.2-0.3mm. In order to reduce the magnetic resistance of the magnetic circuit, a fixed inner stator should be placed in the hollow cup-shaped rotor. The hollow cup-shaped rotor has a small moment of inertia, rapid response, and stable operation, so it is widely used.
When the servo motor of the automatic screen printing machine has no control voltage, as long as the pulsating magnetic field generated by the excitation winding in the stator, the rotor is stationary. When there is a control voltage, a rotating magnetic field is generated in the stator, and the rotor rotates in the direction of the rotating magnetic field. Under the condition of constant load, the speed of the motor changes with the magnitude of the control voltage. When the phase of the control voltage is opposite, the servo motor Will be reversed.
The above is the reason why the precision of the automatic screen printing machine is so high.