As the situation with the coronavirus continues to develop globally, the medical ventilators are especially crucial now in treating cases of COVID-19, the disease caused by the novel coronavirus, because critically ill patients often suffer severe respiratory symptoms. Many companies jump in to supply ventilators needed in coronavirus fight now.
Click here to see how we work hard recently to produce voice coil motor/actuator Magnets for Medical Devices Ventilators To Help Fight New Coronavirus In China
China Magnets Source also provide mounting magnets as magnetic headgear clips on oral-nasal mask of ventilator. The magnets allow for quick release and easy application, and can hold mask in place throughout the night.
Magnets, expecially rare earth magnets are high-value accessories for motor. How to choose a magnet for voice coil motor? This question is very important and related to the performance and the production cost of motor. When selecting the material of the voice coil motor magnet, we need to consider factors such as system performance, magnet working environment and cost.
Ceramic magnets are popular for use in linear actuators because of low cost, reliable supply, good resistance to demagnetization and reasonable magnetic strength.
If a higher energy material is required, then samarium cobalt or neodymium magnets must be considered.
Neodymium magnet is the strongest magnet in the world and the most widely used type of rare-earth magnet. They have higher remanence, much higher coercivity and energy product, but often lower Curie temperature than other types of magnets. the Curie temperature (°C) ranges 310–370.
At moment, special neodymium magnet alloys that include terbium and dysprosium have been developed that have higher Curie temperature, allowing them to tolerate higher temperatures.
But most of time, motor manufacturers use samarium cobalt magnet as a replacement selection if a higher working temperature is required and no need for too high magnetic energy product (BHmax) of the magnet material.
Samarium–cobalt magnets have maximum energy products (BHmax) that range from 14 megagauss-oersteds (MG·Oe) to 33 MG·Oe. It is similar to neodymium magnet in N35 grade.
In addition to the choice of magnet material, how can the performance of the voice coil motor be improved in the design of the magnet?
Suitable magnet thickness. The larger the thickness of the magnet, the stronger the air gap magnetic field and the larger the motor output.