Patent ID: 9607796
Date: 2017-03-28
CPC Classifications: H01F,H01H

Claim:
1. An electromagnetic structure containing a permanent magnet, comprising: an outer yoke, which is hollow cylindrical, and is composed of an upper base of the outer yoke, a lower base of the outer yoke, and an outer yoke sidewall; a first permanent magnet group, comprising a plurality of permanent magnets arranged in a circular shape, wherein, the plurality of permanent magnets in the first permanent magnet group are connected to the lower base of the out yoke, and a magnetization direction of each permanent magnet is along an axial direction of the permanent magnet; an inner yoke, comprising an upper base of the inner yoke, a lower base of the inner yoke, and an inner yoke sidewall, wherein, the inner yoke sidewall is cylindrical, and the upper base of the inner yoke is a circular ring formed by extending outwardly and horizontally from an upper end of the inner yoke sidewall, and the lower base of the inner yoke is a circular ring formed by extending outwardly and horizontally from a lower end of the inner yoke sidewall; and the lower base of the inner yoke is connected to the first permanent magnet group; an armature, comprising an upper base of the armature, a lower base of the armature, and a cylindrical body of the armature; wherein, the cylindrical body of the armature passes through a centre of a through-hole of the inner yoke, and the height of the cylindrical body of the armature is greater than the height of the inner yoke; and the upper base of the armature and the lower base of the armature are circles either having a diameter greater than the inner diameter of the inner yoke sidewall; and a second permanent magnet group, comprising a plurality of permanent magnets arranged in a circular shape, wherein, the plurality of permanent magnets in the second permanent magnet group are connected to the upper base of the out yoke and the upper base of the inner yoke, and a magnetization direction of each permanent magnet is along an axial direction of the permanent magnet.