CN115020062B - Permanent magnet ring assembly with precise magnetic field waveform and preparation method thereof - Google Patents
Permanent magnet ring assembly with precise magnetic field waveform and preparation method thereof Download PDFInfo
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- CN115020062B CN115020062B CN202210415518.6A CN202210415518A CN115020062B CN 115020062 B CN115020062 B CN 115020062B CN 202210415518 A CN202210415518 A CN 202210415518A CN 115020062 B CN115020062 B CN 115020062B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/02—Permanent magnets [PM]
- H01F7/0273—Magnetic circuits with PM for magnetic field generation
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/24—Magnetic cores
- H01F27/26—Fastening parts of the core together; Fastening or mounting the core on casing or support
- H01F27/263—Fastening parts of the core together
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F7/00—Magnets
- H01F7/02—Permanent magnets [PM]
- H01F7/0273—Magnetic circuits with PM for magnetic field generation
- H01F7/0278—Magnetic circuits with PM for magnetic field generation for generating uniform fields, focusing, deflecting electrically charged particles
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Abstract
The invention discloses a permanent magnet ring assembly with a precise magnetic field waveform and a preparation method thereof, belongs to the technical field of permanent magnet rings, and is used for solving the problems of low magnetic energy product and low yield of the existing permanent magnet ring. The permanent magnet ring component provided by the invention comprises a permanent magnet ring and a magnetic conduction ring; the permanent magnet ring is formed by splicing a plurality of magnetic tiles magnetized along the parallel direction; the outer diameter surface of the permanent magnet ring is connected with the inner diameter surface of the magnetic conduction ring; the inner diameter surface or/and the outer diameter surface of the magnetic conductive ring are/is distributed with periodically arranged hollow areas, and the hollow areas are formed by processing and removing a part of materials on the magnetic conductive ring; the hollow area and the magnetic conduction ring body are jointly used as a magnetic field waveform adjusting area. The permanent magnet ring assembly provided by the invention can greatly improve the resolution and precision of the magnetic field waveform, solves the problems of low magnetic energy product and low yield of the existing permanent magnet ring, and can meet the application requirements of high-precision navigation devices.
Description
Technical Field
The invention belongs to the technical field of permanent magnet rings, and particularly relates to a permanent magnet ring assembly with a precise magnetic field waveform and a preparation method thereof.
Background
In recent years, industries such as high-performance motors and navigation control are rapidly developed, and the demand on permanent magnet rings is multiplied. The permanent magnet ring is used as a core component of devices such as a motor, a gyroscope, a magnetic encoder and the like, and has irreplaceable functions. When the existing permanent magnet ring is used, an integral radial multi-pole magnet ring is generally adopted. In a gyroscope, a magnetic encoder and other devices, a magnetic head sensor is generally arranged at a certain distance from the outer circular surface of a magnetic ring, and signals such as displacement, angle and the like are output after the change of air gap flux density is converted. The precision and the volume size of devices such as navigation positioning and the like are directly limited by the precision of magnetic field waveform signals. Under the same external dimension, the larger the number of peaks and valleys of the magnetic field waveform signal is, the smaller the angle or distance corresponding to each peak and valley is, and the higher the resolution of the device is. The stronger the magnetic performance of the magnetic ring is, the larger the corresponding numerical value of the peak-valley magnetic field is, and the smaller the volume of the device can be.
At present, due to the limitation of a preparation process and the characteristics of a radial integral magnetic ring, stress concentration is caused by the non-uniformity of shrinkage at different positions in the sintering process of the magnetic ring, and radial ring cracking is seriously caused. The existing method reduces the cracking phenomenon of the magnetic ring by reducing the orientation field during the preparation, but the method can cause the reduction of the magnetic performance of the magnetic ring. For example, the maximum energy product of the ndfeb integral radial magnetic ring is generally not more than 45MGOe, which is far lower than 54 MGOe which can be achieved by sintering the ndfeb material. Patent CN 101879594B discloses a warm-pressing forming method and a mold for preparing an integral permanent magnet ring with radial texture, the magnetic performance of the magnet ring is as follows: br =1.22T, hci =997 kA/m, (BH) max =321kJ/m 3 (40.5 MGOe after conversion). For another example, in the method for preparing a high-performance radial hot-pressing magnetic ring disclosed in patent CN101202143B, the magnetic energy product of the magnetic ring is 30MGOe to 45MGOe by using a hot-pressing process. Due to the magnetic energy product limitation of the integral radial magnetic ring, the peak value of the magnetic field waveform signal is difficult to improve. Meanwhile, the integral radial magnetic ring has the defects of irregular shape, poor consistency of magnetic performance and uneven surface magnetism due to the reasons of uneven radiation magnetic field, poor mold precision and the like during preparationAnd so on. In addition, the spacing between adjacent magnetic poles of the overall radial magnetic ring is generally not less than 2mm under the constraint of the existing multi-pole magnetizing coil. If the magnetic field signal resolution is to be improved, the number of magnetic poles of the magnetic ring must be increased, however, under the prior art, more magnetic poles can be obtained only by increasing the diameter of the magnetic ring, which results in larger device volume and higher cost.
Disclosure of Invention
In view of the above analysis, the present invention aims to provide a permanent magnet ring assembly with precise magnetic field waveform and a manufacturing method thereof, which can solve at least one of the following technical problems: (1) The qualification rate of the magnetic ring is low due to the characteristic of easy cracking in the existing preparation process of the integral radial magnetic ring; (2) The magnetic energy product of the magnetic ring is lower due to the low radiation orientation field; (3) Limited by magnetizing technology, limited number of magnetic poles and unable to provide high precision magnetic field waveform.
The purpose of the invention is mainly realized by the following technical scheme:
the invention provides a permanent magnet ring assembly with a precise magnetic field waveform, which comprises a permanent magnet ring and a magnetic conduction ring; the permanent magnet ring is formed by splicing a plurality of magnetic shoes magnetized along the parallel direction; the outer diameter surface of the permanent magnet ring is connected with the inner diameter surface of the magnetic conduction ring; the inner diameter surface or/and the outer diameter surface of the magnetic conduction ring are/is distributed with periodically arranged hollow areas, and the hollow areas are formed by processing and removing a part of materials on the magnetic conduction ring; the hollow area and the magnetic conduction ring body are jointly used as a magnetic field waveform adjusting area.
Furthermore, the permanent magnet ring is made of a permanent magnet material.
Furthermore, the magnetic conduction ring is made of soft magnetic materials.
Furthermore, the shape of the hollow area is one or a combination of a plurality of trapezoidal grooves, triangular grooves, rectangular grooves, wedge-shaped grooves, circular grooves, square grooves, circular arc grooves or inverted convex grooves.
Further, a permanent magnet ring formed by splicing the magnetic shoes is an inner N pole and an outer S pole or an inner S pole and an outer N pole; the hollow area is arranged on the outer diameter surface or/and the inner diameter surface of the magnetic conductive ring.
Furthermore, the inner diameter of the magnetic conductive ring is R1, the outer diameter of the magnetic conductive ring is R2, the axial length of the magnetic conductive ring is D, and the ratio of D to the wall thickness R2-R1 is controlled to be 0.1-10.
Furthermore, the magnetic shoes on the permanent magnetic ring are alternately distributed with N poles and S poles, and the inner diameter surface of the magnetic conduction ring corresponding to the splicing gap of the adjacent magnetic shoes is provided with a depressed area.
Further, depressed area and the sunken district alternate distribution, and the depth h3 of the sunken district on the external diameter face of magnetic ring and the depth h4 of the depressed area on the internal diameter face accord with: h3+ h4 is greater than the wall thickness R2-R1.
The invention also provides a preparation method of the permanent magnet magnetic ring assembly with the precise magnetic field waveform, which comprises the following steps:
and 4, integrally magnetizing the assembled assembly, wherein the magnetic poles of the magnetized assembly are distributed as follows: inner N pole, outer S pole or inner S pole and outer N pole.
The invention also provides a preparation method of the permanent magnet magnetic ring assembly with the precise magnetic field waveform, which comprises the following steps:
Compared with the prior art, the invention can realize at least one of the following beneficial effects:
a) The magnetic conduction ring of the permanent magnet ring assembly with the precise magnetic field waveform can guide out the polarity and play a role in magnetic field enhancement, the outer diameter surface of the magnetic conduction ring is used as a working surface, the material adopted by the magnetic conduction ring is easy to process, the process for processing the magnetic conduction ring into various complex shapes is quite mature and reliable, the size and the shape precision can be easily controlled with high precision by means of mechanical processing, and the problems that the outer surface of the permanent magnet ring is used as the working surface in the prior art, the processability of the permanent magnet material is poor, and the defects of cracks, edge breakage, corner falling and the like are easily generated during complex processing are solved.
b) The permanent magnet ring assembly with the precise magnetic field waveform provided by the invention can greatly increase the number of wave crests and wave troughs of a magnetic field signal by processing a hollow area on the magnetic conductive ring to adjust the magnetic field waveform and combining a single-pole magnetizing mode. The processing hollow area on the magnetic conductive ring has various combination forms and mature and reliable processing technology, so that the magnetic conductive ring can be processed according to the bearing limit of the magnetic conductive material. By adjusting the magnetic field waveform, the invention can provide abundant and diverse magnetic field waveforms and greatly improve the resolution of the waveform. Meanwhile, the magnetic conduction ring can not only enhance the magnetic field, but also improve the uniformity of the magnetic field peak-valley signals.
c) The permanent magnet ring assembly with the precise magnetic field waveform is formed by splicing the magnetic shoes, the magnetization directions of the magnetic shoes are magnetized in parallel, the oriented magnetic field can reach 2T during preparation, the problem of cracking does not exist, and the performance of the spliced magnetic ring is far higher than that of an integral ring, so that the volume of the permanent magnet ring can be smaller under the condition of obtaining the same magnetic field intensity.
d) According to the spliced magnetic ring adopted by the invention, because the magnetization direction of the blank of the magnetic ring is parallel magnetization, the problem of cracking does not exist in the sintering process of the blank, so that the yield is greatly improved compared with that of an integral ring; when the magnetic ring is used as a multi-pole magnetic ring, the external magnetic conduction ring can adjust the waveform of the magnetic field to realize the effect of multiplying the number of magnetic poles, so that the size of a single magnetic tile does not need to be made small, the splicing difficulty is low, and the yield is high.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.
Drawings
The drawings, in which like reference numerals refer to like parts throughout, are for the purpose of illustrating particular embodiments only and are not to be considered limiting of the invention.
FIG. 1 is a schematic structural view of a permanent magnet ring assembly of the present invention;
FIG. 2 is a schematic view of the magnetization direction of the magnetic shoe of the present invention;
fig. 3 is a schematic structural view of a permanent magnet ring assembly according to embodiment 1 of the present invention;
fig. 4 is a radial magnetic ring distribution test result of the permanent magnet ring assembly according to embodiment 1 of the present invention;
fig. 5 is a schematic structural view of a permanent magnet ring assembly according to embodiment 2 of the present invention;
fig. 6 is a radial magnetic ring distribution test result of the permanent magnet ring assembly of embodiment 2 of the present invention;
fig. 7 is a schematic structural view of a permanent magnet ring assembly according to embodiment 3 of the present invention;
fig. 8 is a radial magnetic ring distribution test result of the permanent magnet ring assembly according to embodiment 3 of the present invention;
fig. 9 is a schematic structural view of a permanent magnet ring of comparative example 1 of the present invention;
fig. 10 is a radial magnet ring distribution test result of the permanent magnet ring of comparative example 1 of the present invention.
Reference numerals:
1-permanent magnetic ring, 2-magnetic conductive ring, 3-hollow area, 4-magnetic tile, 5-magnetization direction.
Detailed Description
The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention.
The invention provides a permanent magnet ring assembly with a precise magnetic field waveform, as shown in figure 1, the permanent magnet ring assembly comprises a permanent magnet ring 1 and a magnetic conductive ring 2; the permanent magnet ring 1 is formed by splicing a plurality of magnetic shoes 4 magnetized along the parallel direction; the outer diameter surface (namely the outer wall or the outer circular surface) of the permanent magnet ring 1 is connected with the inner diameter surface (namely the inner wall or the inner circular surface) of the magnetic conductive ring 2; the inner diameter surface or/and the outer diameter surface of the magnetic conduction ring 2 are distributed with periodically arranged hollow areas 3, and the hollow areas 3 are formed by processing and removing a part of materials on the magnetic conduction ring 2; the hollow area 3 and the magnetic conduction ring body are jointly used as a magnetic field waveform adjusting area.
Specifically, a peak portion is formed between two adjacent empty regions 3, and correspondingly, the empty region 3 is a valley portion.
It should be noted that the magnetic shoes 4 are magnetized in the parallel direction, and the orientation field can be made larger during the preparation, so that the magnetic performance of the magnetic shoes is higher, and the magnetic performance of the spliced permanent magnetic ring 1 is also higher than that of a radial whole magnetic ring (the orientation field is lower, and the magnetic energy product is small). The magnetic shoe splicing has the disadvantage of poor magnetic pole transitivity, and the arrangement of the magnetic conduction ring 2 can make the external magnetic field of the magnetic shoe 4 magnetized in parallel more uniform, and can also play a role in enhancing the magnetic field. Illustratively, the resolution of the magnetic field waveform signal generated by the permanent magnet ring assembly of the invention is improved by more than 50% compared with that of a radial multi-pole magnetizing integral ring with the same size. Compared with the radial multi-pole magnetizing integral ring with the same size, the magnetic field intensity of the magnetic field signal generated by the permanent magnetic ring assembly is improved by more than 20%.
Specifically, in order to ensure that the permanent magnet ring 1 is difficult to demagnetize after being magnetized, the permanent magnet ring 1 is made of a permanent magnet material. Illustratively, the material of the permanent magnet ring 1 may be neodymium iron boron permanent magnet material, samarium cobalt permanent magnet material, alnico permanent magnet material, or permanent magnetic ferrite.
Specifically, when the permanent magnet ring 1 is made of a neodymium iron boron permanent magnet material, the magnetic energy product of the magnetic shoe 4 is 46-55 MGOe, and the coercive force is 10-37 kOe.
Specifically, in order to ensure that the magnetic conductive ring 2 has good magnetic conductivity, magnetic enhancement and processability, the magnetic conductive ring 2 is made of a soft magnetic material; illustratively, the material of the magnetic conductive ring 2 may be permalloy, silicon steel, electrical pure iron, soft magnetic carbon steel, or soft magnetic ferrite.
Specifically, the shape of the hollow area 3 may be one or a combination of several of a trapezoidal groove, a triangular groove, a rectangular groove, a wedge-shaped groove, a circular groove, a square groove, an arc groove, a wave-shaped groove, or an inverted "convex" groove.
In a possible design, the final magnetizing direction of the magnetic shoe 4 is all the N pole or S pole of the outer diameter surface, and the outer diameter surface of the permanent magnet ring formed by splicing the magnetic shoes 4 is the N pole or S pole as a whole; in this case, the recess 3 of the magnetic ring 2 may be present on the outer diameter surface or/and the inner diameter surface of the magnetic ring 2.
Specifically, the inner diameter of the magnetic conductive ring 2 is R1, the outer diameter is R2, the axial length of the magnetic conductive ring 2 is D, and the ratio of D to the wall thickness R2-R1 is controlled to be 0.1-10.
Specifically, the depth of the recess area 3 on the magnetic conductive ring 2 is h, and the ratio of the depth h to the wall thickness R2-R1 is controlled to be 0.01-0.99, preferably 0.2-0.8.
Specifically, when the outer diameter surface and the inner diameter surface of the flux ring 2 are both provided with the recess regions 3, the recess regions 3 of the outer diameter surface of the flux ring 2 and the recess regions 3 of the inner diameter surface of the flux ring 2 may be alternately distributed, that is, the recess regions 3 (i.e., the valley portions) of the inner diameter surface of the flux ring 2 correspond to the peak portion regions of the outer diameter surface of the flux ring 2, and the peak portion regions of the inner diameter surface of the flux ring 2 correspond to the valley portion regions of the outer diameter surface of the flux ring 2.
Or, the positions of the recessed areas 3 of the outer diameter surface of the magnetic conductive ring 2 and the recessed areas 3 of the inner diameter surface of the magnetic conductive ring 2 may be correspondingly set, that is, the recessed areas 3 (i.e., valley portions) of the inner diameter surface of the magnetic conductive ring 2 correspond to the recessed areas 3 of the outer diameter surface of the magnetic conductive ring 2, at this time, the depths of the two corresponding recessed areas 3 are h1 and h2, and h1+ h2 is controlled to be smaller than the wall thickness R2-R1.
Specifically, the shapes and sizes of the different depressed areas 3 on the magnetic conductive ring 2 may be the same, and the shapes and sizes of the different depressed areas 3 on the magnetic conductive ring 2 may be different; the shape and size of the hollow area 3 can be specifically set according to the requirement.
In a possible design, the final magnetizing direction of the magnetic shoe 4 is that the N pole and the S pole of the outer diameter surface of the permanent magnet ring 1 are alternately distributed. At this time, in order to avoid the N, S poles of the adjacent magnetic tiles 4 from forming a closed magnetic circuit, a recessed region must be provided on the inner diameter surface of the corresponding magnetic conductive ring 2 at the splicing gap of the adjacent magnetic tiles 4. The hollow area 3 of the magnetic ring 2 may be present on the outer diameter surface or/and the inner diameter surface of the magnetic ring 2.
Specifically, the shape of the recessed area may be one or a combination of several of a trapezoidal groove, a triangular groove, a rectangular groove, a wedge-shaped groove, a circular groove, a square groove, an arc groove, a wave-shaped groove, or an inverted "convex" groove.
Specifically, in order to reduce the internal closure of the magnetic field lines and make the external magnetic field larger, the recessed regions and the hollow regions 3 are alternately distributed. The depth h3 of the hollow area 3 on the outer diameter surface of the magnetic conductive ring 2 and the depth h4 of the concave area on the inner diameter surface accord with the following conditions: h3+ h4 is greater than the wall thickness R2-R1.
Specifically, the radial center line of the hollow area on the outer diameter surface is superposed with or forms an included angle theta with the radial center line of the magnetic shoe, theta is more than or equal to 0 and less than or equal to 180/p, and p is the number of the magnetic shoes on the permanent magnet ring.
It should be noted that the difference of the 360-degree peak-valley magnetic field intensity along the circumference of the magnetic field waveform generated by the permanent magnetic ring assembly is less than or equal to 2%; the difference of the magnetic field intensity is less than or equal to 2 percent within the distance of 1.5mm along the upper part and the lower part of the axial central point.
The invention also provides a preparation method of the permanent magnet magnetic ring component with the precise magnetic field waveform, which comprises the following steps:
and 4, integrally magnetizing the assembled assembly, wherein the magnetic poles of the magnetized assembly are distributed as follows: inner N pole, outer S pole or inner S pole and outer N pole.
The invention also provides a preparation method of the permanent magnet magnetic ring component, which comprises the following steps: the method comprises the following steps:
Specifically, in the step 1, a permanent magnet blank is prepared by adopting a rapid hardening and melt spinning-hydrogen breaking-airflow milling-profiling-heat treatment process, and the blank is cut into a required magnetic shoe shape.
The conventional radial integral magnetic ring has the limitation of self characteristics, stress concentration is caused by non-uniformity of shrinkage at different positions in the sintering process of the magnetic ring, and the magnetic ring can be seriously cracked; the peak value of the magnetic field waveform signal is difficult to realize due to the magnetic energy product limitation of the whole radial magnetic ring; in addition, limited by the magnetizing technology, the distance between adjacent magnetic poles of the overall radial magnetic ring is generally not less than 2mm under the constraint of the existing multi-pole magnetizing coil, and if the resolution of magnetic field signals is to be improved, the number of the magnetic poles of the magnetic ring must be increased, however, under the existing technical conditions, more magnetic poles can be obtained only by increasing the diameter of the magnetic ring, which leads to the increase of the volume and the cost of the device. Compared with the prior art, the magnetic conduction ring of the permanent magnet ring assembly provided by the invention can guide out polarity and play a role in magnetic field enhancement, the outer diameter surface of the magnetic conduction ring is used as a working surface, the magnetic conduction ring is made of materials which are easy to process, the process for processing the magnetic conduction ring into various complex shapes is quite mature and reliable, the size and the shape precision can be easily controlled with high precision by means of machining, and the problems that the outer surface of the permanent magnet ring is used as the working surface in the prior art, the processability is poor, and the defects of cracks, edge breakage, corner falling and the like are easily generated in complex processing are solved.
In the conventional multi-pole magnetizing method, when the number of poles N, S is increased to a certain extent, the number of poles cannot be increased continuously due to the magnetizing coil or splicing process, so that the waveform resolution cannot be improved. The permanent magnet ring assembly provided by the invention can greatly increase the number of wave crests and wave troughs of a magnetic field signal by processing a hollow area on the magnetic conductive ring to adjust the waveform of the magnetic field and combining a single-pole magnetizing mode. The processing hollow area on the magnetic conductive ring has various combination forms and mature and reliable processing technology, so that the magnetic conductive ring can be processed according to the bearing limit of the magnetic conductive material. By adjusting the magnetic field waveform, the invention can provide abundant and diverse magnetic field waveforms and greatly improve the resolution of the waveform. Meanwhile, the magnetic conduction ring can not only enhance the magnetic field, but also improve the uniformity of the magnetic field peak-valley signals.
The permanent magnet ring assembly provided by the invention is formed by splicing the magnetic tiles, the magnetization directions of the magnetic tiles are parallel to magnetize, an oriented magnetic field can reach 2T during preparation, the performance of the spliced magnetic ring is far higher than that of an integral ring, and the volume of the permanent magnet ring can be smaller under the condition of obtaining the same magnetic field intensity.
For a traditional radial integral magnetic ring, due to the self expansion anisotropy, stress generated by thermal expansion during processing is uneven, so that the processing difficulty is very high, and cracking is easily caused to cause scrapping. For a traditional spliced multi-pole magnetic ring, in order to obtain more magnetic pole pairs, the number of the magnetic shoe units needs to be increased, which means that the size of a single magnetic shoe unit is continuously reduced, the difficulty of a splicing process is greatly increased, and the qualification rate of the spliced magnetic ring is lower. According to the spliced magnetic ring adopted by the invention, because the magnetic ring direction of the magnetic ring blank is magnetized in parallel, the problem of cracking does not exist, so that the yield is greatly improved compared with that of an integral ring; when the magnetic ring is used as a multi-pole magnetic ring, the external magnetic conduction ring can adjust the waveform of the magnetic field to realize the effect of multiplying the number of magnetic poles, so that the size of a single magnetic tile does not need to be made small, the splicing difficulty is low, and the yield is high.
Example 1
The embodiment provides a permanent magnet ring assembly, as shown in fig. 3, the permanent magnet ring assembly includes a permanent magnet ring 1 and a magnetic conductive ring 2; the permanent magnet ring 1 is formed by splicing a plurality of magnetic tiles 4 (shown in figure 2) magnetized along the parallel direction; the whole outer diameter surface of the permanent magnet ring formed by splicing the magnetic shoes 4 is an N pole or an S pole; the outer diameter surface of the permanent magnet ring 1 is connected with the inner diameter surface of the magnetic conduction ring 2; the outer diameter surface of the magnetic conductive ring 2 is distributed with periodically arranged hollow areas 3, and the hollow areas 3 are formed by processing and removing a part of materials on the magnetic conductive ring 2; the radial center line of the hollow area on the outer diameter surface is superposed with the radial center line of the magnetic shoe; the hollow area 3 and the magnetic conduction ring body are jointly used as a magnetic field waveform adjusting area.
Specifically, the size of the magnetic shoe 4 is R20 × R15 × 10 × 6mm, and the material of the magnetic shoe 4 is a neodymium iron boron permanent magnet material.
Specifically, the material of the magnetic conductive ring 2 is 1J50 permalloy, the outer diameter of the magnetic conductive ring 2 is 46mm, the inner diameter is 40mm, and the thickness is 6mm. The shape of the hollow area 3 is an approximately rectangular groove, the included angle theta of the groove is =90 degrees, the depth h of the groove is =2mm, and the width w of the bottom edge is =1mm. The number of empty regions N =36.
The preparation method of the permanent magnet ring assembly in the embodiment comprises the following steps:
(1) Preparing a permanent magnet ring: preparing a neodymium iron boron magnet ring square blank by adopting the processes of rapid hardening and spinning, hydrogen breaking, jet milling, orientation forming, isostatic pressing, sintering and tempering, wherein the orientation magnetic field is 2T; the magnetic property of the neodymium iron boron material is as follows: br =14.30kgs, hcj =15koe, (BH) max =50MGOe; then processing the neodymium iron boron blank into magnetic tiles with the size of R20 mm R15 mm 10 mm 6mm, wherein the magnetization directions of the magnetic tiles are parallel; after the surface of the magnetic shoe is cleaned, carrying out rust prevention treatment, and finally carrying out a bonding process to obtain a permanent magnet ring in a neutral state after the glue is completely cured;
(2) Processing a magnetic conduction ring: 1J50 permalloy with good processability and soft magnetic property is selected as a magnetic conductive ring material, wherein Bs =1.50T, hc < 15Oe of the soft magnetic material; firstly, processing a 1J50 material into a circular ring with the inner diameter of 40mm, the outer diameter of 46mm and the height of 6mm, then forming a square groove on the outer circular surface, wherein the included angle theta of the groove is =90 degrees, the depth h of the groove is =2mm, the width w of the bottom edge is =1mm, and the number N of the grooves is =36;
(3) Assembling: uniformly coating epoxy resin glue on the outer circular surface of the permanent magnetic ring and the inner circular surface of the magnetic conductive ring, then placing the permanent magnetic ring into the magnetic conductive ring, cleaning redundant residual glue, using a clamp to enable the permanent magnetic ring and the magnetic conductive ring to be concentric and keep the permanent magnetic ring and the magnetic conductive ring from moving, and finally curing for 2 hours in an oven at 100 ℃;
(4) Single-pole magnetizing: placing the bonded permanent magnet ring assembly into a special magnetizing fixture, adjusting voltage and current parameters of a magnetizing machine, and magnetizing the permanent magnet ring assembly; and after the magnetization is finished, a single N pole is arranged on the outer circular surface of the permanent magnet ring assembly.
(5) Measuring the magnetic field waveform: a teslameter is used for testing the air gap magnetic field around the outer circular surface of the permanent magnet ring assembly, and the distribution test result of the radial magnet rings is shown in figure 4; as can be seen from FIG. 4, this embodiment is a unipolar waveform, where small peak-to-valley signals are nested between large peak-to-valley signals, for a total of 108 peak-to-valley, with a difference in magnetic field strength of about 1% over 360 degrees of the circumference. The magnetic field strength was measured using a teslameter over a length of 1.5mm up and down the axial centerline, respectively, and the results showed a difference of about 1.6%; the peak maximum magnetic field signal value is about 485mT, and the trough minimum magnetic field signal value is 175mT.
Example 2
The embodiment provides a permanent magnet ring assembly, and as shown in fig. 5, the permanent magnet ring assembly includes a permanent magnet ring 1 and a magnetic ring 2; the permanent magnet ring 1 is formed by splicing a plurality of magnetic shoes 4 magnetized along the parallel direction (as shown in figure 2); the whole outer diameter surface of the permanent magnet ring formed by splicing the magnetic shoes 4 is an N pole or an S pole; the outer diameter surface of the permanent magnet ring 1 is connected with the inner diameter surface of the magnetic conduction ring 2; the outer diameter surface and the inner diameter surface of the magnetic conductive ring 2 are both distributed with periodically arranged hollow areas 3, and the hollow areas 3 are formed by processing and removing a part of materials on the magnetic conductive ring 2; the hollow areas 3 on the outer diameter surface and the inner diameter surface are alternately distributed, and the hollow areas 3 and the magnetic conduction ring body are jointly used as magnetic field waveform adjusting areas.
Specifically, the size of the magnetic shoe 4 is R20 × R15 × 10 × 6, the material of the magnetic shoe 4 is a neodymium iron boron permanent magnet material, and the magnetic performance of the neodymium iron boron permanent magnet material is as follows: br =14.30kgs, hcj =15koe, (BH) max =50MGOe.
Specifically, the material of the magnetic conductive ring 2 is 1J50 permalloy, the outer diameter of the magnetic conductive ring 2 is 46mm, the inner diameter is 40mm, and the thickness is 6mm. The outer diameter surface and the inner diameter surface of the magnetic conduction ring 2 are both provided with hollow areas 3, and peak parts and valley parts are alternately arranged. The shape of the hollow area 3 is an approximate rectangular groove, and the size parameters of the hollow area on the outer diameter surface of the magnetic conductive ring are as follows: groove included angle θ 1=90 °, groove depth h1=1.5 mm, and base width w1=1mm; the size parameters of the hollow area on the inner diameter surface of the magnetic conduction ring are as follows: a groove included angle theta 2=90 degrees, a groove depth h2=1.5mm, and a bottom edge width w2=1mm; the total number of hollow areas on the inner diameter surface and the outer diameter surface N =36. The positions of the hollow areas 3 of the outer diameter surface of the magnetic ring 2 and the hollow areas 3 of the inner diameter surface of the magnetic ring 2 are alternately distributed, namely the hollow areas 3 of the inner diameter surface of the magnetic ring 2 correspond to peak areas of the outer diameter surface of the magnetic ring 2, and the peak areas of the inner diameter surface of the magnetic ring 2 correspond to valley areas of the outer diameter surface of the magnetic ring 2; the radial center line of the hollow area on the outer diameter surface is superposed with the radial center line of the magnetic shoe, and the radial center line of the hollow area on the inner diameter surface is superposed with the radial center line of the magnetic shoe.
The preparation method of the permanent magnet ring assembly of this embodiment is similar to that of embodiment 1, and is not repeated herein.
The magnetic field waveform measurement is performed on the permanent magnet ring assembly of the embodiment: a teslameter is used for testing the air gap magnetic field at the periphery of the outer circular surface of the permanent magnet ring assembly, and the distribution test result of the radial magnet rings is shown in fig. 6; as can be seen in FIG. 6, this embodiment is a single-pole wave peak-valley structure, with a small valley nested between the two peaks. The number of large and small wave troughs is 36 in total, the number of wave peaks is 36, and 72 peak-trough signals are in total. The difference in the circumferential 360 degree peak-to-valley magnetic field strength is about 1.2%. The magnetic field strength was measured using a tesla meter over a length of 1.5mm up and down the axial centerline, respectively, and the results showed a difference of about 1.8%; the peak maximum magnetic field signal value is about 470mT and the trough minimum magnetic field signal value is 170mT.
Example 3
In the present embodiment, there is provided a permanent magnet ring assembly, as shown in fig. 7, the permanent magnet ring assembly includes a permanent magnet ring 1 and a magnetic conductive ring 2; the permanent magnet ring 1 is formed by splicing a plurality of magnetic shoes 4 magnetized along the parallel direction (as shown in figure 2); the N poles and the S poles of the outer diameter surface of the permanent magnet ring formed by splicing the magnetic shoes 4 are alternately distributed; the outer diameter surface of the permanent magnet ring 1 is connected with the inner diameter surface of the magnetic conduction ring 2; the outer diameter surface of the magnetic conductive ring 2 is distributed with periodically arranged hollow areas 3, and the hollow areas 3 are formed by processing and removing a part of materials on the magnetic conductive ring 2; the hollow area 3 and the magnetic conduction ring body are jointly used as a magnetic field waveform adjusting area. And a concave area is processed at the splicing gap of the adjacent magnetic tiles 4 on the inner diameter surface of the magnetic conduction ring 2.
Specifically, the size of the magnetic shoe 4 is R20 × R15 × 10 × 6, and the material of the magnetic shoe 4 is samarium cobalt permanent magnet material. The magnetic properties of samarium cobalt materials are: br =10.9kGs, hcj ≧ 30kOe, and (BH) max =30 is MGOe.
Specifically, the material of the magnetic conductive ring 2 is DT4C electrician pure iron, and the outer diameter of the magnetic conductive ring 2 is 46mm, the inner diameter is 40mm, and the thickness is 6mm. The hollow area 3 is an approximately rectangular groove, the included angle theta of the groove is =90 degrees, the depth h of the groove is =2mm, and the width w of the bottom side is =1mm; the number of the hollow areas on the outer diameter surface is 36, and the hollow areas on the inner diameter surface are arranged at the splicing gaps of two adjacent magnetic tiles, and the number of the hollow areas is also 36.
The preparation method of the permanent magnet magnetic ring assembly in the embodiment comprises the following steps:
The magnetic field waveform measurement is performed on the permanent magnet ring assembly of the embodiment: a teslameter is used for testing the air gap magnetic field at the periphery of the outer circular surface of the permanent magnet ring assembly, and the distribution test result of the radial magnet rings is shown in fig. 8; as can be seen from FIG. 8, the present embodiment is a N, S alternating peak-to-valley structure waveform, with small peaks and valleys nested between adjacent peaks and valleys. The number of large peaks is 36, the number of large valleys is 36, the number of nested peaks and valleys is 36, and the total number of peak-valley signals is 108. The difference in the circumferential 360 degree peak-to-valley magnetic field strength is about 1.1%. The magnetic field strength was measured using a tesla meter over a length of 1.5mm up and down the axial centerline, respectively, and the results showed a difference of about 1.7%; the peak-to-valley maximum magnetic field signal value is approximately 290mT and the minimum magnetic field signal value is 180mT.
Comparative example 1
As shown in fig. 9, a radially oriented neodymium iron boron permanent magnet ring blank is prepared by using the same formula components as in example 1, wherein the oriented magnetic field is 0.8T; taking a small cylinder sample from a magnetic ring to test magnetic performance, and measuring Br =11.8kGs, hcj =14.7kOe, (BH) max =34MGOe; processing the blank ring into a ring with the outer diameter of 40mm, the inner diameter of 30mm and the height of 6mm; the magnetic ring is placed into a special magnetizing fixture for multi-pole magnetizing, the number of the magnetic poles is 36, and the number of the magnetic poles N, S is half of the number of the magnetic poles. The magnetic field waveform of the air gap magnetic field around the outer circumferential surface of the permanent magnet ring is measured by a tesla meter, and the distribution test result of the radial magnetic ring is shown in fig. 10.
It can be seen from example 3 and comparative example 1 that the number of peaks and valleys of the waveform signal of example 1 is 108, that of comparative example 1 is 36, and that the number of peaks and valleys of the waveform signal is doubled by 3 times, which means that the resolution of the device is increased by 3 times. In addition, the permanent magnet in the embodiment 1 is formed by splicing magnetic shoes magnetized in parallel, and the magnetic performance of the magnetic shoes is higher than that of the whole ring in the comparative example 1, so that the magnetic field strength of the embodiment 1 can reach about 470mT, and the peak magnetic field of the comparative example 1 is 250mT, which is improved by more than 80%.
Comparing example 2 with comparative example 1, it can be seen that the number of peaks and valleys in example 2 is 72, which is increased by 1 time compared to the comparative example, which means that the resolution of the device will be improved by 1 time. Similarly, the magnetic field strength of example 2 was also about 470mT, which was improved by 80% or more compared with 250mT of the comparative example.
In the case of the above examples 1 and 2, both of which are single-pole magnetized, the formula of the magnetic ring is completely the same as that of the comparative example 1, and it can be seen that the magnetic energy product of the comparative example 1 can only reach about 34MGOe due to the limitation of radial magnetization, while the magnetic energy product of the examples 1 and 2 can reach 50MGOe.
In both the example 3 and the comparative example 1, N, S poles are alternately distributed, and in the example 3, the inner and outer diameter surfaces of the magnetic conductive ring are provided with the hollow areas, wherein the hollow areas of the inner diameter surface are arranged at the gaps formed by splicing N, S magnetic poles, so that the phenomenon that magnetic lines of force are closed is avoided, under the condition of the same number of the magnetic poles, the number of peaks and valleys reaches 108, and the comparative example only has 36 peaks and valleys, so that the resolution of a magnetic field waveform signal is far higher than that of a traditional method.
In particular, the present invention can perform various grooving operations to form the recess, such as wedge-shaped grooves, circular grooves, square grooves, circular arc grooves, etc., by means of deformation and combination.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (8)
1. A permanent magnet ring component with a precise magnetic field waveform is characterized by comprising a permanent magnet ring (1) and a magnetic conductive ring (2); the permanent magnet ring (1) is formed by splicing a plurality of magnetic tiles (4) magnetized along the parallel direction; the outer diameter surface of the permanent magnet ring (1) is connected with the inner diameter surface of the magnetic conduction ring (2); the inner diameter surface or/and the outer diameter surface of the magnetic conductive ring (2) are/is distributed with periodically arranged hollow areas (3), and the hollow areas (3) are formed by processing and removing a part of materials on the magnetic conductive ring (2); the hollow area (3) and the magnetic conduction ring body are jointly used as a magnetic field waveform adjusting area;
the magnetic conduction ring (2) is made of soft magnetic material; the outer diameter surface of the magnetic conduction ring (2) is used as a working surface;
the shape of the hollow area (3) is one or a combination of a plurality of trapezoidal grooves, triangular grooves, rectangular grooves, wedge-shaped grooves, circular grooves, square grooves, circular arc grooves or inverted-convex-shaped grooves.
2. A permanent magnet ring assembly according to claim 1, characterized in that the material of the permanent magnet ring (1) is a permanent magnet material.
3. The permanent magnet ring assembly according to claim 1, wherein the permanent magnet ring (1) formed by splicing the magnet tiles (4) is an inner N pole, an outer S pole or an inner S pole and an outer N pole; the hollow area (3) is arranged on the outer diameter surface or/and the inner diameter surface of the magnetic conductive ring (2).
4. A permanent magnet ring assembly according to claim 3, wherein the inner diameter of the magnetic conductive ring (2) is R1, the outer diameter is R2, the axial length of the magnetic conductive ring (2) is D, and the ratio of D to the wall thickness R2-R1 is controlled to be 0.1-10.
5. The permanent magnet ring assembly according to claim 1, wherein the magnetic shoes (4) on the permanent magnet ring (1) are alternately distributed with N poles and S poles, and the inner diameter surface of the corresponding magnetic conduction ring (2) at the splicing gap of the adjacent magnetic shoes (4) is provided with a recessed area.
6. A permanent magnet ring assembly according to claim 5, wherein said recessed areas and said recessed areas (3) are alternately arranged, and the depth h3 of the recessed areas (3) on the outer diameter surface and the depth h4 of the recessed areas on the inner diameter surface of said ring (2) are in accordance with: h3+ h4 is greater than the wall thickness R2-R1.
7. A method for preparing a permanent magnet ring assembly with a precise magnetic field waveform, which is used for preparing the permanent magnet ring assembly as claimed in claim 3 or 4, and comprises the following steps:
step 1, preparing a permanent magnet ring: processing a permanent magnet blank magnetized in the parallel direction to prepare a magnetic shoe in a neutral or magnetized state, cleaning the surface of the magnetic shoe, bonding, and completely curing glue to obtain a permanent magnet ring, wherein the magnetization direction of each magnetic shoe on the permanent magnet ring is in the parallel direction;
step 2, preparing a magnetic conductive ring, and processing a hollow area on the inner diameter surface or/and the outer diameter surface of the magnetic conductive ring;
step 3, assembling and connecting the permanent magnet ring and the magnetic conduction ring to obtain an assembled assembly, wherein the outer diameter of the permanent magnet ring is tightly attached to the inner diameter of the magnetic conduction ring, if the permanent magnet ring is in a neutral state, the step 4 is required to be magnetized, and if the permanent magnet ring is in a magnetized state, a final permanent magnet ring assembly is obtained;
and 4, integrally magnetizing the assembled assembly, wherein the magnetic poles of the magnetized assembly are distributed as follows: inner N pole, outer S pole or inner S pole and outer N pole.
8. A method for preparing a permanent magnet ring assembly with a precise magnetic field waveform, which is used for preparing the permanent magnet ring assembly as claimed in claim 5 or 6, and comprises the following steps:
step 1, preparing a permanent magnet ring: processing a permanent magnet blank magnetized in the parallel direction to prepare a magnetic shoe, cleaning the surface of the magnetic shoe, and then magnetizing the magnetic shoe in a parallel magnetizing mode, wherein the magnetizing direction of the magnetic shoe is an outer N pole, an inner S pole or an outer S pole and an inner N pole;
step 2, preparing a magnetic conduction ring: firstly, processing a sunken area on the inner diameter surface of the magnetic conductive ring, wherein the sunken area is distributed on the inner diameter surface of the magnetic conductive ring corresponding to the splicing gap of the adjacent magnetic tiles, and then processing a sunken area on the outer diameter surface and/or the inner diameter surface;
step 3, splicing and assembling: the magnetic tiles are sequentially and alternately bonded on the inner diameter surface of the magnetic conduction ring according to the N, S poles of the outer diameter surface, and the gaps of the adjacent magnetic tiles correspond to the depressed areas on the inner diameter surface of the magnetic conduction ring; and (4) putting the bonded assembly into an oven, and obtaining the permanent magnet ring assembly after the glue is completely cured.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2599854Y (en) * | 2003-02-16 | 2004-01-14 | 吴文胜 | Anisotropic ferrite multipolar magnetic ring |
| CN110943554A (en) * | 2019-10-25 | 2020-03-31 | 杭州史宾纳科技有限公司 | Tile-shaped magnet with halbach array structure effect and manufacturing method |
| CN215064570U (en) * | 2021-05-13 | 2021-12-07 | 深圳市瑞达美磁业有限公司 | Magnetic drum and magnetic encoder with same |
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| EP3125257B1 (en) * | 2015-07-31 | 2018-01-03 | Shin-Etsu Chemical Co., Ltd. | Dipole ring magnetic field generator |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2599854Y (en) * | 2003-02-16 | 2004-01-14 | 吴文胜 | Anisotropic ferrite multipolar magnetic ring |
| CN110943554A (en) * | 2019-10-25 | 2020-03-31 | 杭州史宾纳科技有限公司 | Tile-shaped magnet with halbach array structure effect and manufacturing method |
| CN215064570U (en) * | 2021-05-13 | 2021-12-07 | 深圳市瑞达美磁业有限公司 | Magnetic drum and magnetic encoder with same |
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