Contoured-field magnets

摘要

Apparatus and methods for manufacturing magnets, and magnets, having magnetically oriented grains, and apparatus including such magnets. The field of a permanent magnet may be shaped by applying an external field to the material from which the magnet is made in such a way as to magnetize different regions of the material in different directions. The apparatus may include, and the methods may involve, a metal-powder press that may press metal powder in the presence of a magnetic field. The press may compress the powder in an axial direction. The field may have flux lines that are transverse to the axial direction. The field may have flux lines that are along the axial direction.

主权项

1. A sintered powder hard magnet having a magnetic axis, the magnet comprising a top surface normal to the axis and a bottom surface normal to the axis, the bottom surface set apart from the top surface by a thickness that is between about 3 mm and about 6 mm, and generating a magnetic field that at a location about 4 mm from the top surface, has a component that is parallel to the axis and has a magnitude greater than 1500 Gauss.