Permanent magnet body with symmetric magnetic field intensity of right and left arc, manufacturing method and apparatus

Abstract

The invention provides a permanent magnet, the magnetic densities of a left arc and a right arc are symmetrical, and the permanent magnet is tile-shaped, wherein the cross sections of the left arc and the right arc of the tile-shaped permanent magnet are circular arcs, and the magnetic densities on the same height position of the left arc and the right arc of the tile-shaped permanent magnet are same. During the formation of an orientation field, a blank mould of a magnetic tile is provided with such a position in a loop of the orientation field: the straight lines of the left arc and the right arc of the magnetic tile of the permanent magnet are vertical to a circular arc line of a magnetizing loop, and the position of the magnetizing loop is closest to the blank mould of the magnetic tile. The difference between the magnetic densities of the left arc and the right arc are less than 3 percent, and can easily reach less than 1 percent, thereby improving the efficiency of a motor, and avoiding the problems of noise and service life.

Description

technical field [0001] The invention relates to the preparation of a permanent magnet device, in particular to a permanent magnet with symmetrical left and right arc magnetic field strengths of magnetic tiles, a preparation method and equipment. Background technique [0002] The permanent magnet device is an important part of the DC motor. Generally, the permanent magnet material adopts a series of products ranging from rare earth, AlNiCo to strontium barium ferrite. In the process, the method of orientation field is used to orient the blank in a strong magnetic field to achieve the permanent magnetic field strength fixed after pre-orientation of the finished product after magnetization, thereby obtaining an anisotropic permanent magnet, which is based on the anisotropic permanent magnet The process is widely used because of the inherent memory properties of the material, and the finished product after sintering and magnetization is closely related to the strength and direct...

AI Technical Summary

Problems solved by technology

[0005] It is easy to understand that if the permanent magnets with symmetrical (difference greater than 3%) of the left and right arc magnetic field strengths cannot be provided, it is easy to cause the rotor to vibrate in the direction perpendicular to the axis, and noise and short life cannot be avoided

In particular, the motor composed of a pair of permanent magnet tiles has a high speed and is more prone to unbalanced operation of the motor. In practice, this problem has been ignored.

In practice, permanent magnets with symmetrical left and right arc magnetic field strengths are often required. This kind of symmetrical permanent magnets is especially important for DC motors above a certain speed, otherwise it will bring a lot of electromagnetic noise and seriously affect the life of the motor.

Such DC motors have many applications in automobiles and computers: such as fuel pump motors, water pump motors and fan cooling motors, etc. If this kind of motor has a structure with opposite magnetic poles (a pair of permanent magnets), the speed often reaches 3000 rpm As mentioned above, since the existing market cannot provide permanent magnets with symmetrical left and right arc magnetic field strengths, the existing motor noise cannot be solved, and it also affects the overall quality of domestic electromechanical products.

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