The adjustable magnetic couplings are composed of three parts: a conductor rotor, a permanent magnet rotor and a regulator. The permanent magnet rotor is on the inside of the conductor rotor, separated by an air gap, and rotates independently with the respective rotating shafts; the regulator adjusts the gap between the permanent magnet rotor and the conductor rotor to change the transmission between the conductor rotor and the permanent magnet rotor. The conductor rotor is installed on the input shaft, and the permanent magnet rotor is installed on the output shaft. When the conductor rotor rotates, the conductor rotor and the permanent magnet rotor produce relative motion, and the magnetic field generates eddy current on the conductor rotor. At the same time, the eddy currents the induced magnetic field interacts with the permanent magnetic field to drive the permanent magnet rotor to rotate in the same direction as the conductor rotor. As a result, the torque on the input shaft is transmitted to the output shaft. The output torque is the same as that of the conductor rotor and the permanent magnet rotor. It is related to the size of the gap between them, the smaller the gap, the greater the torque, and vice versa.
Advantages
Speed regulation
According to the actual operating conditions on site, the air gap of the magnetic coupler can be adjusted to achieve speed regulation and achieve the purpose of energy saving and environmental protection. And this kind of speed regulation has more advantages than high-voltage frequency converter speed regulation, and there is no interference of high-order harmonics (high-order harmonics cause great damage to the power grid, which improves the unreliability of electrical instruments and increases on-site faults. difficulty of judging).
a) soft start
Reduce the motor starting load, the motor starts easily, and the starting time is shortened. Since the copper rotor of the magnetic coupler does not cut the magnetic field lines and no induced magnetic field is generated at the moment of motor startup, there is no torque on the copper rotor, and the moment of inertia of the copper rotor itself is small, so the motor is approximately equal to the copper rotor with the magnetic coupler Start with no load. When the motor directly drives the load, the whole process from the start of the motor to the start of the load is completed at one time. After the magnetic coupling drive is installed, the whole starting process becomes two stages: the first stage starts the motor with the copper rotor of the magnetic couplings first. The second stage is that the copper rotor of the magnetic coupler drives the permanent magnet rotor to start at full load. Therefore, the whole starting process is smooth and the impact is small. It has the function of soft start/soft stop, which can effectively reduce the starting current of the motor and solve the phenomenon of water hammer and cavitation. The motor and load can be started and stopped selectively, which greatly improves the system's start-stop performance.
b) energy saving
It can make the motor work in the maximum efficiency area all the time, and it will not fluctuate greatly due to the change of overload. The speed of the water pump can be adjusted according to the working conditions of the system, which can save a lot of electric energy.
When the speed transmitted by the motor to the load changes from n1 to n2, the relationship between Q, H, P and the speed is as 
follows:
It can be seen that the flow rate Q is directly proportional to the speed n of the motor, while the pressure is proportional to the square of the speed, and the required shaft power P is proportional to the cube of the speed. So, when 80% of the rated flow is required, by adjusting the motor speed to 80% of the rated speed, the required power will only be 51.2% of the original, and the water pressure of the system will only be 64% of the original.
Vibration reduction
a) The vibration amplification transmission of the rigid coupling is greatly reduced. The magnetic coupling replaces the original rigid coupling, so that the motor and the load are not mechanically connected, so that the vibration on the load side will not be transmitted to the motor side, and the vibration on the motor side will not be transmitted to the load side. At the same time, it also cuts off the amplification effect of vibration during the transmission process, so the vibration amplification effect of the rigid coupling can be eliminated and the vibration of the system can be reduced.
b) It can greatly reduce system vibration caused by shaft bending, thermal expansion and other reasons.
c) Greatly extend the life of bearings and seals. Since there is no mechanical connection between the motor and the load, there is no wear and tear, which reduces the vibration amplitude of the system and prolongs the life of the motor and load, especially the bearings and seals.
No mechanical connection
a) With overload protection function, it improves the reliability of the whole motor drive system. Since there is no mechanical connection between the motor and the load, when the load is overloaded or stalled, the speed-regulating magnetic coupling can automatically completely disconnect the torque transmission from the motor to the load. At this time, the motor runs without load and the load stops. Completely eliminate the system damage and huge loss caused by the overload of the load system.
b) make finding and fault isolation very easy.
c) Simple installation and less maintenance work.