Arc Motor Magnets: Unleashing High-Efficiency Performance in Modern Motors
Discover the exceptional capabilities of arc motor magnets, engineered for high-torque applications and revolutionizing the efficiency of modern motor designs in various industries.
Introduction of Arc Motor Magnet
Arc magnets are named by their special geometry. They are also called arc motor magnets because most arc magnets are used in electric motors or generators. Due to the technical limitation in manufacturing radially magnetized ring magnets, individual arc magnets remain a reasonable and cost-effective option for most permanent magnet motors. Tengye Magnetic manufactures arc motor magnets made of neodymium-iron-boron and supplies Sm2Co17 magnet and hard ferrite for a variety of motor companies. We also support R&D projects of motor companies by quickly delivering sample magnets.
Magnet Materials of Arc Motor Magnets
Neodymium magnets and ferrite magnets dominate the market of permanent magnet motors magnets. Neodymium arc magnets are used in high performance motors or motors with compact size, while ferrite arc magnet in relatively large motors with relatively low torque requirement. Besides, Sm2Co17 magnet (2nd generation of rare earth magnet) always remains in existence in motor application because of its excellent magnetic strength and temperature stability.
In recent years, with the increasing demand for high performance motor, laminated magnets have been quickly developed and commercialized. Magnet Lamination Technology is aimed to reduce eddy current loss and prevent overheat. They are available in both sintered neodymium magnets and Samarium-Cobalt magnets.
Ideally, arc motor magnets are thought to be radially magnetized in order to create an arrangement similar to a radial ring magnet. However, this is not the case when it comes to the commercial market of arc magnets. Because the magnetization direction of anisotropic magnets is predetermined during pressing and it’s difficult to achieve radial orientation during the pressing process. The most cost-efficient way is to diametrically magnetize the magnet blank. For special motor requirement, radially magnetized ring magnet can also be produced.
Coating Options for Neodymium Arc Magnets
Neodymium magnets are prone to corrosion and therefore need surface protection. Common coating types include Nickel (NiCuNi), Zinc, Epoxy and Passivation (Phospharization). It’s important to note that nickel is a ferromagnetic material and NiCuNi coating has a slight effect on the magnetic flux. Zinc coating is the best option when it comes to cost but it provides no better corrosion resistance than Nickel and Epoxy coating. Epoxy coating is an organic coating and provides the best corrosion resistance. NdFeB magnet nano coating is characterized by its excellent corrosion resistance and has become an alternative to nickel and epoxy coating.
Alternative Magnet Solutions for High-Performance Permanent Magnet Motors
Beyond traditional arc and rectangular magnets, multipole ring magnets have emerged as a popular choice in recent years. For electric motor applications, these versatile magnets can be categorized into radially magnetized ring magnets and polar-anisotropic ring magnets, commonly referred to as Halbach ring magnets. Boasting superior precision and reduced assembly costs, these ring magnets offer a competitive edge in modern motor designs.