The magnetic coupling is mainly composed of copper rotor, permanent magnet rotor and control mechanism. Generally, the copper rotor is connected to the motor shaft, the permanent magnet rotor is connected to the working machine, and there is an air gap between the copper rotor and the permanent magnet rotor (called air gap), there is no mechanical connection for torque transmission; Its working principle is: the magnetic field lines generated by the permanent magnet rotor act on the copper rotor to generate eddy currents, and the eddy currents generate an induced magnetic field during rotation and cut the magnetic field lines to achieve torque transmission; in this way, a soft (magnetic) magnetic field is formed between the motor and the working machine. connection, by adjusting the air gap to realize the change of the shaft torque and speed of the working machine; due to the existence of the air gap, the starting of the motor in the working system is a gradual process from no load to the actual load (soft start), due to the different air gap adjustment methods, Magnetic couplings are divided into: standard type, torque-limiting type, speed-regulating type and other different types of products.
1. Standard magnetic coupling
1) The working machine is a device with a large starting inertia.
2) There are high-precision alignment requirements for the connection of each working unit in the system.
3) The vibration of the working machine will affect the motor. For example: air preheater, coal mill, etc.
●Technical advantages
1) It is completely maintenance-free, with normal use, its service life is longer than that of general-purpose couplings.
2) After the large centering error is installed, its influence is "zero" in the system work.
3) Improve the starting ability of the motor and realize the soft start/stop of the motor.
4) It can isolate the vibration transmission of each working unit in the system.
5) Extend the service life of the wearing parts and bearings of each working unit in the system.
6) There is no requirement for the working environment.
2. Torque-limited magnetic coupling
1) The working machine is a device with a large starting inertia.
2) There are high-precision alignment requirements for the connection of each working unit in the system.
3) The vibration of the working machine will affect the motor.
4) When the working machine is overloaded, overload protection is required for the motor. For example: coal mill, conveyor belt, agitator, etc.
●Technical advantages
1) It is completely maintenance-free, and under normal use, its service life is much longer than that of torque-limiting hydraulic couplings.
2) After the large centering error is installed, its influence is "zero" in the system work.
3) Improve the starting ability of the motor and realize the soft start/stop of the motor.
4) It can isolate the vibration transmission of each working unit in the system.
5) The hydraulic coupler has its own power consumption due to bearing rotation, centering loss and impact loss of the medium in the working chamber. The magnetic coupling does not have any mechanical transmission parts, and has low energy consumption. Its power consumption is about 5% lower than that of the hydraulic coupling.
6) When the system is overloaded, the hydraulic coupling protects the system in the form of ejecting the medium in the working chamber. If the system wants to resume work, it must be shut down, the hydraulic coupling is removed, filled with medium, and installed for the fusible plug, align and install the hydraulic coupler, and then start the machine to work. The magnetic coupling can automatically disengage when the system is overloaded, and after the overload point passes, the magnetic coupling can automatically return to work, that is to say: the system installed with the magnetic coupling can troubleshoot without stopping, without affecting production.
3. Adjustable speed magnetic coupling All centrifugal mechanical systems with:
1) A system in which the actual working condition parameters of the working machine are lower than its rated parameters and are in constant operation.
2) The system in which the actual working condition parameters of the working machine are lower than its rated parameters and the operating conditions vary. For example: water pumps, slurry pumps, fans, etc.
●Technical advantages
Under the condition that the output speed of the motor is constant, the air gap between the copper rotor and the permanent magnet rotor can be adjusted through the controller to realize stepless adjustment of the speed of the working machine. And the power of the motor is transmitted to the working machine smoothly and without impact through the soft (magnetic) connection. The larger the air gap between the copper rotor and the permanent magnet rotor, the smaller the output torque of the speed-regulating magnetic coupling and the lower the output speed (the greater the slip of the speed-regulating magnetic coupling); the copper rotor and the permanent magnet rotor the smaller the air gap, the greater the output torque of the speed-regulating magnetic coupling, and the higher the output speed (the smaller the slip of the speed-regulating magnetic coupling). When matching with centrifugal machinery, due to the characteristics of centrifugal machinery, the lower the speed, the smaller the working parameters, the less power consumption, and the smaller the output power of the motor. Therefore, in actual work, when the actual working parameters of the centrifugal mechanical system are required to be lower than its rated parameters, the speed of the working machine can be adjusted (reduced) through the speed-adjustable magnetic coupling to meet the changing requirements of the working parameters. Requirements; Therefore, the centrifugal machinery in the system operates below its rated speed, and the motors work under energy-saving conditions.