(1) The electromagnetic speed regulating motor consists of a cage motor, an electromagnetic slip clutch and a DC excitation power supply (controller). The power of DC excitation power supply is small, and it usually consists of single-phase half-wave or full-wave thyristor rectifier. Changing the conduction angle of thyristor can change the magnitude of excitation current. ?
(2) The electromagnetic slip clutch consists of armature, magnetic pole and excitation winding. The armature has no mechanical connection with the latter and can rotate freely. The armature is coaxially connected with the motor rotor, which is called the active part and is driven by the motor; The magnetic pole is connected with the load shaft through the coupling, which is called the driven part.
(3) When the armature and magnetic pole are stationary, if DC is applied to the excitation winding, several pairs of N and S poles will be formed along the circumferential surface of the air gap, and their magnetic flux will pass through the armature. When the armature rotates with the drag motor, the armature induces eddy current due to the relative motion between the armature and the magnetic pole. This eddy current interacts with the magnetic flux to generate torque, which drives the rotor with magnetic pole to rotate in the same direction, but its speed is always lower than the armature speed N 1. This is a slip speed regulation method. By changing the DC excitation current of the sliding clutch, the output torque and speed of the clutch can be changed.
2. Wiring description: U, V and W of the motor are connected to the power supply through the contactor. 1 and 2 of speedometer are connected to 220V power supply. 3 and 4 (two thick ones) are connected to the excitation coil of the speed regulating motor (the two terminals in front of the junction box on the left side of the motor are numbered). 5, 6, and 7(U, V, and W) are connected to the speed-regulating motor tachogenerator (the three terminals behind the left junction box are numbered).
5. How to use it
(1) When using the electromagnetic governor, reset the speed control knob to zero before the motor starts, and then adjust the speed after the motor starts; Before stopping, the speed control knob is also reset to zero, and then the motor stops.
(2) During the test run, start the motor first, then turn on the power indicator light of the controller and turn the speed regulating knob. At this time, the reading on the tachometer gradually rises, and the speed can be stabilized at a certain value according to the needs of the production process.
Extended data:
Speed regulation characteristics of electromagnetic speed regulating motor;
1, simple device structure and control circuit, reliable operation and convenient maintenance;
2. Smooth speed regulation and stepless speed regulation;
3, no harmonic influence on the power grid;
4, speed loss, low efficiency.
5. This method is suitable for production machinery with medium and small power, stable power and short-term low-speed operation.
References:
Baidu encyclopedia-speed regulating motor