Magnetic couplings are utilized in many functions inside pump, chemical, pharmaceutical, course of and safety industries. They are sometimes used with the purpose of reducing put on, sealing of liquids from the environment, cleanliness wants or as a safety issue to brake over if torque suddenly rises.
The most typical magnetic couplings are made with an outer and internal drive, both build up with Neodymium magnets so as to get the best torque density as possible. By optimizing the diameter, air hole, magnet measurement, variety of poles and choice of magnet grade, it’s possible to design a magnetic coupling that suits any software in the vary from few millinewton meter as a lot as a quantity of hundred newton meters.
When only optimizing for prime torque, the designers typically tend to forget considering the influence of temperature. If the designer refers to the Curie point of the person magnets, he’ll declare that a Neodymium magnet would fulfill the necessities as much as greater than 300°C. Concurrently, you will need to embrace the temperature dependencies on the remanence, which is seen as a reversible loss – usually around 0,11% per degree Celsius the temperature rises.
Furthermore, a neodymium magnet is under pressure during operation of the magnetic coupling. This implies that irreversible demagnetization will happen long before the Curie point has been reached, which usually limits the usage of Neodymium-based magnetic coupling to temperatures beneath 150°C.
If higher temperatures are required, magnetic couplings manufactured from Samarium Cobalt magnets (SmCo) are usually used. SmCo isn’t as strong as Neodymium magnets but can work up to 350°C. Furthermore, the temperature coefficient of SmCo is only 0,04% per degree Celsius which implies that it may be utilized in functions the place performance stability is needed over a bigger temperature interval.
New generation In collaboration with Copenhagen Atomics, Alfa Laval, Aalborg CSP and the Technical University of Denmark a brand new era of magnetic couplings has been developed by Sintex with support from the Danish Innovation Foundation.
The objective of the venture was to develop a magnetic coupling that might broaden the working temperature area to reach temperatures of molten salts round 600°C. By exchanging the inside drive with a magnetic materials containing a higher Curie level and boosting the magnetic subject of the outer drive with special magnetic designs; it was attainable to develop a magnetic coupling that started at a decrease torque degree at room temperature, but only had a minor reduction in torque stage as a function of temperature. เครื่องมือวัดpressure resulted in superior efficiency above 160°C, irrespective of if the benchmark was towards a Neodymium- or Samarium Cobalt-based system. This can be seen in Figure 1, the place it’s proven that the torque stage of the High Hot drives has been examined up to 590°C on the internal drive and nonetheless performed with an almost linear discount in torque.
The graph additionally exhibits that the temperature coefficient of the High Hot coupling is even decrease than for the SmCo-system, which opens a decrease temperature market where performance stability is necessary over a bigger temperature interval.
Conclusion At Sintex, the R&D division continues to be creating on the expertise, but they have to be challenged on torque degree at either different temperature, dimensions of the magnetic coupling or new functions that haven’t beforehand been possible with standard magnetic couplings, in order to harvest the total potential of the High Hot technology.
The High Hot coupling just isn’t seen as a standardized shelf product, however as an alternative as custom-built by which is optimized for particular purposes. Therefore, additional development shall be made in shut collaboration with new companions.
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