Magnetic couplings are utilized in many applications within pump, chemical, pharmaceutical, course of and safety industries. They are typically used with the aim of lowering wear, sealing of liquids from the setting, cleanliness wants or as a security factor to brake over if torque suddenly rises.
The commonest magnetic couplings are made with an outer and internal drive, each construct up with Neodymium magnets in order to get the best torque density as potential. By optimizing the diameter, air hole, magnet measurement, number of poles and selection of magnet grade, it is attainable to design a magnetic coupling that suits any software in the vary from few millinewton meter up to several hundred newton meters.
When solely optimizing for high torque, the designers typically are inclined to neglect considering the affect of temperature. If the designer refers again to the Curie point of the person magnets, he’ll claim that a Neodymium magnet would fulfill the necessities as a lot as greater than 300°C. Concurrently, you will want to embody the temperature dependencies on the remanence, which is seen as a reversible loss – typically round zero,11% per diploma Celsius the temperature rises.
Furthermore, a neodymium magnet is underneath stress during operation of the magnetic coupling. This implies that irreversible demagnetization will happen lengthy before the Curie level has been reached, which usually limits using 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 sturdy 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 could be utilized in purposes the place performance stability is needed over a bigger temperature interval.
เพรสเชอร์เกจ In collaboration with Copenhagen Atomics, Alfa Laval, Aalborg CSP and the Technical University of Denmark a new generation of magnetic couplings has been developed by Sintex with support from the Danish Innovation Foundation.
The function of the venture was to develop a magnetic coupling that could broaden the working temperature area to reach temperatures of molten salts around 600°C. By exchanging the internal drive with a magnetic materials containing the next Curie point and boosting the magnetic field of the outer drive with particular magnetic designs; it was possible to develop a magnetic coupling that began at a decrease torque stage at room temperature, however only had a minor discount in torque degree as a function of temperature. This resulted in superior performance above 160°C, no matter if the benchmark was towards a Neodymium- or Samarium Cobalt-based system. This can be seen in Figure 1, where it’s shown that the torque level of the High Hot drives has been tested as much as 590°C on the inner drive and nonetheless carried out with an virtually linear discount in torque.
The graph additionally reveals that the temperature coefficient of the High Hot coupling is even lower than for the SmCo-system, which opens a lower temperature market the place efficiency stability is important over a bigger temperature interval.
Conclusion At Sintex, the R&D department is still creating on the know-how, but they must be challenged on torque degree at both different temperature, dimensions of the magnetic coupling or new purposes that haven’t beforehand been attainable with standard magnetic couplings, so as to harvest the full potential of the High Hot technology.
The High Hot coupling isn’t seen as a standardized shelf product, however as an alternative as custom-built by which is optimized for specific applications. Therefore, additional development shall be made in shut collaboration with new partners.