The magnetic couplings is mainly composed of two parts: a magnetic conductor connected to the shaft end of the motor and a permanent magnet connected to the load end. In operation, according to the principle of eddy current induction, the relative motion of the above two parts generates a magnetic field, and in this way an eddy current will be generated in the disc-shaped conductor, and the magnetic field generated by the eddy current and the magnet attract each other. Magnetic couplings are also called magnetic couplings, mainly It is composed of two parts: the magnetic conductor connected to the shaft end of the motor and the permanent magnet connected to the load end. In operation, according to the principle of eddy current induction, the relative motion of the above two parts generates a magnetic field, and in this way, an eddy current will be generated in the disc-shaped conductor, and the magnetic field generated by the eddy current and the magnet attract each other, so that the two parts of the rotor and the conductor pass through the air. The gap transmits torque, so that the motor and the load are changed from the original hard connection to the soft connection.
According to the above principles, in recent years, China has developed different types of magnetic couplings such as delay type, torque-limiting type, and speed-regulating type. It has obvious effects in the transformation of water pumps, fans, bucket elevators, zipper machines, scraper machines, belt conveyors, etc. in major domestic power energy industries, cement industries, steel industries, and chemical industries.
Advantages and application
With the development of technological innovations such as energy saving and consumption reduction in cement enterprises and internal potential tapping, such as magnetic couplings, dynamic harmonic energy saving devices, etc., they have gradually been applied and promoted in the cement industry.
Advantage:
No physical connection, good soft start effect; no fuel, no electricity, no maintenance;
Isolate vibration transmission, extend equipment life; tolerate alignment errors, easy to install and disassemble; The structure is simple and reliable, adapting to harsh environments; overload torque limiting protection, quick recovery of production.
Scope of application: bucket elevator, zipper machine, scraper machine, belt conveyor instead of the original hydraulic coupling Overload protection: When the equipment is overloaded and stalled, the rotation speed of the permanent disk that is not as good as the load quotient drops sharply or even stops, and a huge repulsion occurs between the conductor disk and the permanent disk, which quickly pushes the magnet disks on both sides to the middle, and the permanent disk and the conductor disk The air gap becomes larger, for example, the load is disengaged, and the protection of the transmission system is realized. When the fault is eliminated, the load speed gradually increases, and the equipment enters the normal working state again.
Typical application cases
Case 1: A cement group's 10,000-ton line enters the kiln bucket elevator (motor power: 2*200kw)
Reasons for the renovation: the installation position of the drive equipment of the bucket elevator into the kiln is high, the space is narrow, the fluid coupling has seal oil leakage, and the bearing is damaged.
Retrofit purpose: reduce the failure rate of equipment, reduce the amount of maintenance, improve the reliability of equipment, and ensure the normal operation of production.
Transformation effect: The starting current of the motor is reduced, the vibration of the equipment is reduced, and the service life of the motor and the reducer is prolonged. Automatic overload protection function, no trouble of hydraulic oil, realizes maintenance-free equipment.
Case 2: 6,000-ton linear inclined zipper machine for a cement group (motor power: 3*110kw)
Reasons for the renovation: the installation location of the chicken wings of the original equipment is harsh, the site temperature is high, the dust is large, the fusible plug of the hydraulic coupling melts and sprays oil when the equipment is blocked, the maintenance volume is large and the frequency is high.
Retrofit purpose: reduce equipment failure rate, reduce maintenance, improve equipment stability, and ensure normal operation of production.
Transformation effect: The permanent magnet coupling does not need hydraulic oil and is suitable for various harsh environments. The automatic overload protection function realizes the maintenance-free equipment, and the failure rate is basically zero in harsh environments, which has won unanimous praise from customers.
Case 3: A power group 2*1000MW unit coal conveyor belt conveyor (motor power: 2*375kw)
The reason for the modification: the original hydraulic coupling was used to connect, and the fusible plug was often melted and sprayed with oil due to the impact load during the operation of the equipment. The maintenance procedure was cumbersome and time-consuming.
Retrofit purpose: to reduce equipment failures caused by impact tea loading, improve the normal operation rate of equipment, improve equipment stability, and ensure the normal operation of production.
Transformation effect: realize flexible start, isolate system vibration transmission, provide automatic protection function when driving overload, prolong the service life of reducer and motor, and reduce the impact on the power grid. The magnetic coupling is basically maintenance-free, which greatly reduces the workload of maintenance and improves work efficiency.
Case 4: A power group 2*1000MW unit bucket wheel cantilever belt (motor power: 1*132kw)
The reason for the modification: the cantilever belt of the original bucket wheel machine was connected by a liquid coupling, the impact load was relatively large and the vibration was high when starting, and the motor often alarmed and shut down abnormally. In addition, the relative failure rate of the reducer is high, and the high-speed shaft will be damaged once a year on average, seriously affecting the normal operation of the system.
Retrofit purpose: reduce system vibration, reduce equipment failure rate, improve equipment stability, and ensure normal operation of production.
Retrofit effect: The vibration value of the motor and reducer is reduced, the life of the motor and reducer is prolonged, the impact current of the motor is greatly reduced, and the automatic overload protection function realizes the maintenance-free equipment. The user is very satisfied with this modification.
Electricity, steel, cement, and chemical industries adopt new permanent magnet energy-saving technology and equipment to reduce energy consumption, reduce vibration, reduce maintenance costs, and achieve the purpose of energy conservation and environmental protection.