neodymium magnet

The biggest risk in the use of permanent magnet motors is demagnetization caused by high temperature. As we all know, the key component of permanent magnet motors is neodymium magnet, and neodymium magnet is most afraid of high temperature. It will gradually demagnetize under high temperature for a long time. The higher the temperature, the greater the risk of demagnetization.   Once a permanent magnet motor loses its magnetism, you basically have no choice but to replace the motor, and the cost of repair is huge. How do you determine whether a permanent magnet motor has lost its magnetism?   1. When the machine starts running, the current is normal. After a period of time, the current becomes larger. After a long time, the inverter will be reported to be overloaded.   First, you need to make sure that the inverter selected by the air compressor manufacturer is correct, and then confirm whether the parameters in the inverter have been changed. If there are no problems with both, you need to judge by back electromotive force, disconnect the head from the motor, perform no-load identification, and run no-load to the rated frequency. At this time, the output voltage is the back electromotive force. If it is lower than the back electromotive force on the motor nameplate by more than 50V, it can be determined that the motor is demagnetized.     2. After demagnetization, the running current of permanent magnet motor will generally exceed the rated value.   Those situations where overload is reported only at low or high speed or occasionally reported, are generally not caused by demagnetization.   3. It takes a certain amount of time for a permanent magnet motor to demagnetize, sometimes several months or even one or two years.   If the manufacturer selects the wrong model and causes current overload, it does not belong to motor demagnetization.   An important indicator of permanent magnet motor performance is the high temperature resistance level. If the temperature resistance level is exceeded, the magnetic flux density will drop sharply. The high temperature resistance level can be divided into: N series, resistant to more than 80℃; H series, resistant to 120℃; SH series, resistant to more than 150℃. The motor's cooling fan is abnormal, causing the motor to overheat. The motor is not equipped with a temperature protection device. Ambient temperature is too high. Improper motor design.

When choosing a magnetic filter to fit the different shapes of injection molding machines and extruder hoppers, there are several key factors to consider:   1. Hopper shape and size: First, the shape and size of the magnetic filter should match the hopper of the injection molding machine or extruder. For hoppers of different shapes, such as round, square, or other special shapes, the design of the magnetic filter also needs to be adjusted accordingly to ensure that it can fit tightly on the hopper and effectively capture iron impurities.   2. Magnetic strength: The magnetic strength of the magnetic filter is an important consideration when choosing. The magnetic strength should be strong enough to adsorb and capture iron impurities in the hopper, but not too strong to avoid damage to the hopper or the magnetic frame itself. Therefore, when choosing a magnetic filter, it is necessary to determine the appropriate magnetic strength based on the type and amount of iron impurities that may be present in the hopper. All the magnetic filters produced by our factory are made of neodymium magnet material, with magnetic field strength ranging from 8000-14000GS, which can be applied to different needs.   3. Use environment: The working environment of the injection molding machine and extruder may be different, such as temperature, humidity, and dust. Therefore, when choosing a magnetic filter, it is necessary to consider whether it can work properly in this environment. For example, for high temperature or high humidity environments, you should choose a magnetic stand that is resistant to high temperatures and waterproof and moisture-proof!   4. Maintenance and cleaning: The magnetic filter may require regular maintenance and cleaning during use. Therefore, when choosing a magnetic filter, the convenience of its maintenance and cleaning should be considered. For example, some magnetic filters may be designed to be easy to disassemble and clean, which will help reduce maintenance time and costs.   In summary, when choosing a magnetic filter with different hopper shapes for injection molding machines and extruders, it is necessary to consider multiple factors such as hopper shape and size, magnetic strength, use environment, and convenience of maintenance and cleaning.    Communicating with a permanent magnet supplier when choosing a magnetic rack is recommended to ensure that the selected magnetic filter can meet the actual production needs.