Preparation method of radially oriented permanent magnet ring and radially oriented device

Abstract

The invention relates to a preparation method of a radial orienting permanent magnetic ring and a radial orienting device used by the same. The radial orienting device comprises an inner magnetic pole capable of also being used as a die core and a die for forming a die cavity together with the inner magnetic pole; the outside of the die is sleeved with an outer magnetic pole for forming an orienting magnetic field; and the outer magnetic pole moves up and down along the axial direction of the inner magnetic pole along with the continuous up-and-down change of the height of magnetic powder in the pressing process so as to implement that each position of a magnet along the axial direction is sufficiently and uniformly oriented. On the basis of 360-degree radial magnetization, an outer magnetic pole head of the outer magnetic pole of the radial orienting device moves up and down to be subjected to selective radial magnetization along displacement change of the height of a blank when a circular ring-shaped magnet is pressed and formed; radial orienting uniformity of a radial ring is greatly improved; and moreover, nonuniformity of the radial ring in the axial direction is improved to a considerable degree.

Description

technical field [0001] The invention relates to a method and equipment for preparing a radially oriented permanent magnet ring, in particular to a method and a device capable of realizing orientation uniformity of a ring-shaped magnet on a 360° circumference at any height. Background technique [0002] In the field of motors, circular magnets oriented radially or radially have a wide range of application prospects, and have incomparable advantages compared with a certain number of circular disc combinations. At present, there are four main methods of making circular magnets with radial orientation: [0003] The first is the method of extruded magnetic field orientation: the upper and lower magnetic poles are both N poles or S poles. During the pressing process, the two homopolar magnetic heads are extruded into the inner cavity of the radial ring mold, and a radiation magnetic field is formed through the magnetic permeable mold. This method improves the uniformity of the r...

AI Technical Summary

Problems solved by technology

This method improves the uniformity of the ring-shaped magnet in the circumferential direction to a certain extent, but the uniformity of the ring in the height direction is very poor, and the biggest deficiency is the orientation magnetic field obtained when the inner diameter of the radial ring is small The strength will be greatly reduced

[0004] The second is the segmented orientation method: the ring is oriented in segments, and each segment is guided into a magnetic field for orientation. Although this method achieves radial orientation, it leads to uneven orientation of the ring along the circumferential direction.

The uneven orientation will not only seriously affect the overall magnetic properties of the radial ring, but also lead to stress concentration due to the different shrinkage rates in the sintering process of different parts of the orientation, and more seriously cause the radial ring to crack

[0005] The third is the forming orientation method: the method is that there is relative rotational movement between the magnetic powder and the orientation magnetic field during the forming process. This orientation method can solve the problem of uneven orientation in the circumferential direction caused by segmented orientation. During the continuous movement along the circumference, the pressing is also carried out synchronously, so there is also a certain degree of inhomogeneity in the orientation

[0006] The fourth method is that the application number 200910201694.4 mentions that the alternating current through the electromagnet is used to generate a rotating orientation magnetic field, so as to realize the orientation of the circular magnet by the rotating magnetic field, and realize that the strongest magnetic field rotates and scans every part of the magnet sequentially, reducing kinematic pair, but there is inhomogeneity in the orientation of the magnet along the circumferential direction

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