System for concentrating and controlling magnetic flux of a multi-pole magnetic structure

摘要

An improved system for concentrating magnetic flux of a multi-pole magnetic structure at the surface of a ferromagnetic target uses first pole pieces having a magnet-to-pole piece interface with a first area and a pole piece-to-target interface with a second area substantially smaller than the first area for concentrating flux of the multi-pole magnetic structure at each pole piece-to-target interface, where the target can be a ferromagnetic material, complementary pole pieces, or a gap. The improved system may also include a magnetic circuit having second pole pieces located between the first pole pieces and the target that controls the flux directed from the first pole pieces to the target.

主权项

1. A magnet assembly, comprising:
a multi-pole magnetic structure comprising one or more pieces of a magnetizable material having a plurality of polarity regions for providing a magnetic flux, said magnetizable material having a first saturation flux density, said plurality of polarity regions being magnetized in a plurality of directions; and a plurality of pole pieces of a ferromagnetic material for integrating said magnetic flux across said plurality of polarity regions, said ferromagnetic material having a second saturation flux density, each pole piece of said plurality of pole pieces having a magnet-to-pole piece interface with a corresponding polarity region and a pole piece-to-target interface with a target, said magnet-to-pole piece interface having a first area, said pole piece-to-target interface having a second area, said magnetic flux being routed into said pole piece via said magnet-to-pole interface and out of said pole piece via said pole piece-to-target interface, said routing of said magnetic flux through said pole piece resulting in an amount of concentration of said magnetic flux at said pole piece-to-target interface corresponding to a first ratio of the first area divided by the second area, said amount of concentration of said magnetic flux being limited by a second ratio of the second saturation flux density divided by the first saturation flux density, wherein said pole-piece-to-target interface of said pole piece achieves said second saturation flux density when said first ratio equals said second ratio, and wherein said first ratio is at least fifty percent of said second ratio.