JP2021141801A5 - - Google Patents

Claims (13)

A cylindrical or columnar polar anisotropic magnet having 2N poles whose number of poles is a multiple of a natural number N ,
A polar anisotropic magnet, wherein a surface magnetic flux density at magnetic pole positions in the circumferential direction of the cylindrical or columnar shape is 450 mT or more . When the amount of magnetic flux leaking in the circumferential direction of the cylindrical shape or columnar shape is formed in a sine wave shape synchronized with the number of poles, and the sine wave is the primary component, the entire harmonic component excluding the primary component 2. The polar anisotropic magnet according to claim 1, wherein the ratio is 10% or less. 2. A variation in the amount of leakage magnetic flux in the axial direction of said cylindrical or columnar shape is plus or minus 5% or less with respect to the average value of the amount of leakage magnetic flux through the coaxial top and bottom. 2. The polar anisotropic magnet according to 2 . A rotor comprising the polar anisotropic magnet according to any one of claims 1 to 3 , the outer surface of which is covered with a protective tube. 5. The rotor according to claim 4 , having shafts outside both end faces of said polar anisotropic magnets. 6. A rotor according to claim 4 or 5 , capable of rotating at 20,000 rpm or more. A rotating machine comprising the rotor according to any one of claims 4 to 6 and a concentrated winding or distributed winding stator. The rotating machine according to claim 7 , which is used by being mounted on a moving body. Neodymium magnet powder having an average particle size of 1.0 to 5.0 μm and containing a lubricant of 1.0% by mass or less is filled into a pseudo-cylindrical mold cavity at a packing density of 3.4 to 4.0 g/cm ^{3 .} a filling step to obtain a powder-filled mold;
The powder-filled mold is loaded into an orientation device, and an orientation magnetic field of 1.0 to 5.0 T is applied to the filled neodymium magnet powder without applying pressure to orient the neodymium magnet powder, an orientation step to obtain an oriented mold;
A sintering step of inserting the oriented mold into a sintering furnace and sintering the mold together to obtain a sintered body;
A method for manufacturing a cylindrical or cylindrical polar anisotropic magnet, comprising: 10. The method of manufacturing a polar anisotropic magnet according to claim 9 , wherein the shape of the mold cavity is designed so that the sintered body has a cylindrical shape or a columnar shape. 11. The pole according to claim 9 or 10 , characterized in that the orienting step uses the orienting device capable of orienting to have an anisotropy of 2N poles, where the number of poles is a multiple of a natural number N. A method for manufacturing an anisotropic magnet. The orientation step includes
After loading the powder-filled mold into an orientation device and applying pressure in a direction perpendicular to the orientation direction without applying pressure to the filled neodymium magnet powder, a pressure of 1.0 to 5.0 T is applied in the orientation direction. A step of orienting the neodymium magnet powder by applying an orientation magnetic field to obtain the oriented mold,
A method for producing a polar anisotropic magnet according to any one of claims 9 to 11 . A heavy rare earth metal ( R ) or an R-based alloy containing a heavy rare earth metal (where R is selected from Dy, Tb , Ho A method for producing a polar anisotropic magnet, characterized in that the R element is brought into contact with the magnet and heat-treated to diffuse the R element into the magnet.