WO2014029047A1

WO2014029047A1 - Anisotropic nd-fe-b composite magnetic stripe, manufacturing method therefor, and device using same

Info

Publication number: WO2014029047A1
Application number: PCT/CN2012/001462
Authority: WO
Inventors: 周连明
Original assignee: 南通万宝实业有限公司
Priority date: 2012-08-20
Filing date: 2012-10-29
Publication date: 2014-02-27
Also published as: CN103624261A; CN103624261B

Abstract

A manufacturing method for an anisotropic Nd-Fe-B composite magnetic stripe, comprising the procedures of: mixing, batch mixing, screw extruding to form sheets and orientating, demagnetizing, roller rolling, cutting, etc. and using CPE as a magnetic powder composite material. Also disclosed are a magnetic stripe manufactured using the manufacturing method for an anisotropic Nd-Fe-B composite magnetic stripe, and an external rotation motor, an external transmission motor, a variable-frequency ceiling fan motor and a hub type generator which are manufactured using the anisotropic Nd-Fe-B composite magnetic stripe. The efficiency of this manufacturing method for an anisotropic Nd-Fe-B composite magnetic stripe is high, and the manufactured anisotropic Nd-Fe-B composite magnetic stripe has good ductility, and is applicable to an external rotation motor or generator.

Description

Heterogeneous neodymium iron boron composite magnetic strip, manufacturing method thereof and device using the same

The invention relates to a magnetic material for an externally rotating motor or a generator, in particular to an isotropic NdFeB composite magnetic strip and a manufacturing method thereof, and an externally rotating motor, an externally driven motor, and a method A variable frequency ceiling fan motor, a flower drum generator. Background technique

At present, the heterogeneous NdFeB composite magnetic powder is only used in the internal rotation motor or generator. In order to meet the needs of the internal rotation motor or generator, the processing of the heterogeneous NdFeB composite magnetic powder is to add an epoxy tree to the magnetic powder. The ester is used as a binder, and then compressed into a ring magnet by a press, and then cured at a temperature of 150 to 200 ° C. The alignment magnetic field must be added during compression of the press because the coercive force of the NdFeB material is high. Therefore, it is necessary to add a large magnetic field to obtain a 100% orientation. However, the magnetic field is increased, the current is increased, and the heat of the opposing coil is also increased. Therefore, the coil needs to be cooled. Usually, the coil is cooled by using mineral-free water. Since the mineral-containing water forms scale in the tube wall of the coil, the scale adheres to the tube wall to make the coil cooling effect worse. In addition, minerals also cause an eddy current in the tube wall, and a short circuit occurs when the coil is energized, thereby eroding the tube wall to thin the tube wall, and finally passing through the tube wall to short-circuit the coil to break the field coil. The cooling water is cooled by the cooling machine. The cooling tower cannot be used to avoid polluting the water. However, in the limited space of the press, this method is not infinite and can be enlarged upwards, because each machine has a size specification when designed. In contrast, the size of the machine frame has its fixed size. Dimensions, while the orientation field coil is mounted inside the formwork. Therefore, the alignment magnetic field is not large enough, resulting in poor orientation of the shaped magnet material. In order to solve the above disadvantages, the induction coil is wound around the middle mold to heat. The middle mold is also called the female type, which is a kind of mold. The outer portion of the magnetic powder induction coil is wound around the coil of the magnet oriented magnetic field. Since the coercive force of the neodymium iron boron magnetic powder is lowered after being heated, the temperature is usually 150 degrees Celsius, so that the alignment magnetic field can be greatly reduced. However, after solving the alignment magnetic field, subsequent problems occur again. Because the dissimilar NdFeB is added to the epoxy resin as a binder during the forming, the adhesive is also heated when the mold is heated. In addition to being difficult to enter the cavity, the magnetic powder may also form a bridge in the mold. This in turn causes uneven density of the magnets. However, the inner rotor motor magnet must use a ring magnet, so the use of the isotropic NdFeB composite magnetic powder to manufacture the internal rotor rotor magnet must be compressed by the press.

The core of low-carbon home is energy saving, but energy saving does not mean sacrificing the comfort of living, it is not Turn off the air conditioning or heating system. In fact, low-carbon life is an attitude, that is, under the premise of minimizing the impact on human living environment, and even helping to improve the living environment of human beings, people's mind and body are in a comfortable state. Ceiling fans tend to be unstable and noise may be quite large. And on a sultry night, how much the user wants to sleep peacefully under the cool breeze. This type of application is exactly what BLDC/PMSM motors really do, because these innovative motors have high efficiency, high power density, high torque and low noise, but unlike AC induction motors and DC brush motors, DC is not available. The brush motor, ie the BLDC motor, must be equipped with a drive control circuit to achieve efficient co-operation of the stator and rotor. For some ceiling fan manufacturers, this demand may bring some technical challenges, reflected in the control circuit design or motor design, or both of these challenges, the ceiling fan allows the home air convection to maintain a comfortable environment Home appliances, Taiwan has sold 27 million ceiling fans per year to Europe and the United States. At the same time, the CFM/w standard of the US Star has been implemented. Therefore, there will be a stronger demand for the energy-saving design of the ceiling fan.

The design of DC brushless ceiling fans mostly uses an externally-rotating motor design. The motor rotor magnet usually uses a ferrite rubber magnetic strip as the power source for the ceiling fan drive. Since the magnetic energy product of the rubber magnetic strip is about 1.5 MW0e, it is necessary to use rubber magnetic strips of various sizes in order to improve the wattage of different ceiling fans. In order to improve the above disadvantages, there is a ring bond. Iron-boron magnets instead, although the magnetic energy product can be greatly improved, about 8~9MG0e, but the magnetic energy product can not meet the design of different power ceiling fans, so different wattage ceiling fan motors can not change the width of the magnet, ie 5〜2. Oram, therefore, in the case of the mass of the NdFeB magnet, the wall thickness of the ring-bonded NdFeB magnet is only 1. 5~2. There is severe deformation in the magnet hardening process. In order to meet the motor assembly, magnet processing is difficult to avoid, so it is necessary to increase the cost of magnet materials and processing.

The bicycle electric light is a device that is rotated by the tire, and then transmitted to the rotating wheel of the electric lamp, and then used by the electric lamp to supply energy to the electric lamp. The early bicycle electric lamp has a similar appearance to the bottle. Gradually, there are various types of motors with different shapes and voltages and different wattages, but the basic principle of operation and construction are constant. The permanent magnet used inside the conventional electric lamp is an isometric sintered ferrite magnet or an aluminum, nickel or cobalt cast magnet. However, more than 90% use the former, because the price is cheap and the physical characteristics are good. The only drawback is that the magnetic properties are much worse than the latter. Since the motor of this type uses the friction between the two sides of the front or rear tire and the central axis of the motor to drive the magnet. One of the disadvantages is that the cyclist's physical load increases. The second tire is easy to wear and reduces the life of the tire. In addition, the current generated by this motor is alternating current. If it is caused by product failure or accidental, it will cause personal injury. Although the voltage is very low, it cannot be said to be absolutely safe.

For the shortcomings of traditional electric lights. Scientists made a major reform around 1995, in this way The bicycle's electric light is called a hub-type generator. Its advantage is that it is more labor-saving than the traditional one, and it can be attached with a brake disc. The hub generator is mounted on the front wheel of the bicycle. The magnet is mounted inside the aluminum hub shell to form a rotor, and the stator portion is mounted on the bicycle mandrel. The traditional type of electric motor rotor is rubbed by the outer side of the tire. When the tire rotates one revolution, the center rotor of the electric lamp may have turned a hundred turns, so the magnetic force may not be so strong, and the number of poles is not so much. The isotropic ferrite magnet That is to meet the demand. However, the hub-type generator is mounted on the axle of the bicycle, so the rotation speed is synchronized with the tire, so the characteristics of using the magnetic material should not be too bad, and the number of poles should not be too small, otherwise the power generation amount is too low to meet the design goal. If a ring-shaped bonded ferrocene magnet is used, the size is Φ 57 χ Φ 54. 6 x t 22 mm, the thickness of the magnet is easily deformed, and it is not easy to be assembled into the aluminum case. Therefore, most of the hub-type generators are currently made by injection molding magnets, that is, when the injection molding is carried out, a 1. 2 mm ring-shaped back iron is added, and the same is applied at the same time as the neodymium-iron-boron. This prevents magnet deformation and facilitates assembly with the aluminum casing. The material of the injection magnet is mixed with NdFeB 94% and nylon 6%. Then, the inner diameter of the ring magnet is 28 poles. The magnetic core of the magnet is required to be magnetized. The material properties are: Br: 5000~6000 Gauss, bHc: 3700^4700 0e, iHc: 8000~10, 000 0e, BHmax: 5. 5~7. 5 MGOe, Density: 5. 7 gr/cm3 , the magnetic density of the surface after magnet magnetization is 2,000 Gauss. It is feasible to injection the NdFeB while adding the back iron. However, due to the high processing cost of the annular magnet, the material properties of the wet formed sintered ferrite are as follows; Br: 3900^4100 Gauss, bHc: 3000^ 3400 0e, iHc: 3050~3550 0e, (BH) max: 3. 8~4. 0 MGOe, Density: 4. 85~4. 95 gr/cm3 The surface magnetic flux density is about 1800 Gauss.

The advantages of the hub-type generator using ferrite magnet anisotropic magnet are as follows: 1. The price of magnet is cheap; 2. The temperature range is -3 (Tl20 °C is acceptable; 3. Tension resistance. Compression and hardness are good; 4, strong acid and alkali resistance and moisture resistance, can withstand the harsh environment; 5, is an environmentally friendly recycled material. But its shortcomings are also obvious: 1, must have a number of tile-like (Segment type) magnet group to form a ring magnet; 2 Because it is a combination of several tiles, it is labor in the processing group, and the internal roundness is poor. If necessary, it may need to be ground. 3. Because it is composed of several tile magnets, between the disk and the disk. There will be a gap, so there will be a Cogging phenomenon during operation, and it will feel less smooth when rotated by hand;

4. The magnet made of ferrite magnets is only slightly insufficient in magnetic force of 1800 Gauss. The material properties of other parts must be changed.

5. Because the sintered ferrite magnet is brittle, it may break on the bumpy ground, causing the magnet to kill the drum, and the bicycle has the concern of rollover. The "isolateral" in the field means that the magnetic force of the magnet has only one symmetry plane, and the magnetic force of the other pairs of faces is the same as the square. Such a sintered ferrite magnet is referred to as "a heterogeneous sintered ferrite magnet". Summary of the invention

The technical problem to be solved by the present invention is to provide a heterogeneous NdFeB composite magnetic fiber in view of the above-mentioned deficiencies of the prior art. The manufacturing method of the strip. The manufacturing method of the heterogeneous NdFeB composite magnetic strip adopts CPE as a magnetic powder composite material, and has high production efficiency, and the produced heterogeneous NdFeB composite magnetic strip has good ductility, and is especially suitable for an externally-rotating motor or a generator.

In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for manufacturing an isotropic NdFeB composite magnetic strip, comprising the following steps:

a, mixing: mixing NdFeB magnetic powder, chlorinated polyethylene, vulcanizing agent, vulcanizing agent and heat stabilizer; b, batch mixing: pour two or more batches of magnetic powder into the mixing barrel Inside, mixing in the barrel to form a mixed magnetic powder;

c. Spiral extrusion sheeting and orientation: The mixed magnetic powder after batch mixing is sent to a screw conveyor for extrusion to form a magnetic sheet, and then the magnetic sheet is oriented by a permanent magnet to demagnetize the oriented magnetic sheet. ;

d. Roller rolling: After step c, the extruded magnetic sheet is extended by using a rolling roller, and at the same time, the extrusion force of the Luo conveyor is controlled to shape the sheet into a desired thickness and density;

e. Cutting: The shaped magnetic sheet is cut by a cutter to be cut to form a strip-shaped magnetic strip of a desired size.

As a further improvement aspect of the present invention, in step _a, the mass ratio of 92% NdFeB anisotropic magnet powder, 6% of chlorinated polyethylene, 0.9% of vulcanizing agent, 0.3% of The vulcanizing agent and the 0.8% heat stabilizer are kneaded, the mixing time is 90 minutes, and the mixing temperature is controlled below 70 ° C;

As a further improvement of the technical solution of the present invention, the vulcanizing agent is dicumyl peroxide; the vulcanizing agent is triallyl isocyanurate or trihydroxypropionate trimethacrylate; the heat The stabilizer is magnesium oxide.

The technical solution adopted by the present invention is directed to: an isotropic NdFeB composite magnetic strip manufactured by the above-described method for manufacturing a heterogeneous NdFeB composite magnetic strip.

As a further improvement of the aspect of the present invention, the width of the NdFeB anisotropic composite magnetic strips is 400 mm, a thickness of 5 mm ₀

As a further improvement of the technical solution of the present invention, the magnetic characteristics of the hetero-small NdFeB composite magnetic strip are: remanence (Br): 7. 95~8. 25 KG; intrinsic coercive force (iHc): 8 2^9. 2 0e; Maximum magnetic energy product (BH) max : 11. 7~13. 2 MG0e.

For the externally-rotating motor, the technical solution adopted by the present invention is: An external-transmission type generator comprising a rotor magnet, wherein: the rotor magnet is made by using the above-mentioned heterogeneous neodymium-iron-boron composite magnetic strip.

For the externally-rotated generator, the technical solution adopted by the present invention is as follows: An external-rotating generator includes a rotor magnet, and the rotor magnet is made by using the above-mentioned heterogeneous neodymium-iron-boron composite magnetic strip.

For the variable frequency ceiling fan motor, the technical solution adopted by the invention is: a variable frequency ceiling fan motor, including a rotor magnet, The utility model is characterized in that: the rotor magnet is formed by using the above-mentioned hetero-island X-iron-boron composite magnetic strip.

For the hub-type generator, the technical solution adopted by the present invention is: A hub-type generator comprising a rotor magnet, wherein: the rotor magnet is made by using the above-mentioned heterogeneous neodymium-iron-boron composite magnetic strip.

The method for manufacturing the heterodragon neodymium iron boron composite magnetic strip adopts CPE as the magnetic powder composite material, and CPE is the English abbreviation for chlorinated polyethylene, which is a random product prepared by the chlorine substitution reaction of polyethylene, which is high in saturation. Molecular materials, almost no double bond structure. Chlorine content is about 30~40%, non-toxic and tasteless, with excellent weather resistance, ozone resistance, colorless at normal temperature and pressure, strong oxidation, chemical resistance and aging resistance, good oil resistance It has good flame retardancy and coloring properties, good toughness, flexibility at -30'C, good compatibility with other bismuth molecular materials, high decomposition temperature, and decomposition to produce HC1. HC1 can catalyze the dechlorination of CPE. CPE is a polyethylene rubber, excellent in oil resistance, and contains chlorine in CPE. It has excellent flame retardant properties and is resistant to burning and dripping. It is compatible with lanthanide flame retardant, chlorinated paraffin, A1 (0H) ₃ The appropriate proportion of the three can be combined to obtain flame retardant materials with excellent flame retardancy and low cost. CPE has good processing performance and outstanding high filling. In addition, the processing fluidity of the filled material is excellent, and the surface of the product is bright. Due to the low Mooney property, the amount of plasticizer can be reduced during processing, so that the surface of the article is not precipitated and is not easily bonded; the heterogeneous NdFeB composite magnetic strip of the present invention is rolled and cut to obtain a finished product, so mass production The various sizes are simple and easy, and there is no need to make various molds, no matter in the development and mass production of the products. After the heterocyclic NdFeB composite magnetic powder is made into an isotropic NdFeB composite magnetic strip, it has good ductility and can be used in an externally rotating motor or generator.

The heterodiction NdFeB composite magnetic strip of the invention adopts an isotropic NdFeB composite magnetic strip CPE as a magnetic powder composite material, which has good ductility and is used in an externally rotating motor or generator.

The outer rotor type motor of the present invention and the rotor magnet of the variable frequency ceiling fan motor of the present invention are produced by using the above-described heterogeneous neodymium iron boron composite magnetic strip. The rotor magnet can be completely attached to the inverter fan motor rotor shell or the outer rotor motor rotor shell, and the magnetic energy product can reach 11. 7~13. 2 MGOe, so the outer diameter of the rotor shell can be greatly reduced; The design method, so the assembly project is easy to automate, there is no problem in the use of ring-bonded NdFeB. Moreover, since the thickness of the magnetic strip is hooked and the magnet is closely attached to the casing of the motor, the air gap between the stator and the stator can be reduced, and the efficiency of the variable frequency motor can be improved; because the magnetic strip material has high characteristics, different motor wattages In the design, only need to change the thickness of the stator silicon steel sheet and the width of the magnetic strip, it can produce a variety of different wattage ceiling fan motors, saving the cost of stator opening and copper wire, in the management of the fixture In addition to the volume reduction, the variable frequency ceiling fan can effectively reduce the resistance of the ceiling fan during operation, increase the rotation speed, achieve efficiency, save energy, and effectively reduce the cost of parts.

The externally-rotating generator of the present invention and the hub-type generator of the present invention each use the above-mentioned hetero-nungedo-boron-boron composite magnetic strip as a rotor magnet. Because the thickness of the heterodyne NdFeB composite magnetic strip is uniform, and the magnet is closely attached to the aluminum shell of the hub, the air gap between the stator and the stator can be reduced, and the efficiency of the variable frequency motor can be improved. It can easily reach the specification of 3W/6V at a speed of fifteen kilometers per hour; Because the magnetic strip material has high properties, although the unit price per kilogram is higher than that of sintered ferrite anisotropic magnet, its weight is only 1/3 of that of sintered ferrite anisotropic magnet, and the relative cost is not improved, but it saves The cost of the stator and coil magnetically permeable material; the one-piece heterogeneous NdFeB composite magnetic strip has a perfect curve, and does not have a meal when riding, which can improve the rider's comfort; The square-iron-iron-boron composite magnetic strip has a certain elasticity, and there is no danger of cracking on the bumpy road surface, which can improve the safety of the bicycle. DRAWINGS

Figure 1 is a manufacturing flow diagram of the present invention.

Figure 2 is a partial enlarged view of A of Figure 1.

Fig. 3 is a schematic view showing the structure of a hub generator in the seventh embodiment.

4 is a schematic view showing the structure of a radiation-oriented annular strip-shaped heterodoid NdFeB composite magnet.

Fig. 5 is a schematic view showing the structure of an anisotropic square-shaped heterocyclic NdFeB composite magnet.

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings. detailed description

Example 1

Referring to FIG. 1 and FIG. 2, the manufacturing method of the present heterogeneous NdFeB composite magnetic strip includes the following steps:

a 8%热性。 The agglomeration: a mass ratio of 92% of NdFeB magnetic powder, 6% of chlorinated polyethylene, 0.9% of the vulcanizing agent, 0.3% of the vulcanizing agent and 0.8% heat The stabilizer is placed in the kneading machine 1 for kneading, the kneading time is 90 minutes, and the kneading temperature is controlled to be 70 ° C or less;

b. Batch mixing: Pour two or more batches of the mixed magnetic powder into the mixing tank 2, and mix in the mixing barrel to form a mixed magnetic powder 10;

c. Spiral extrusion sheeting and orientation: The mixed magnetic powder after batch mixing is sent to a screw conveyor 3 for extrusion to form a magnetic sheet 4, and then the magnetic sheet 4 is oriented by the orientation magnetic field 6 generated by the permanent magnet 5, The oriented magnetic sheet 4 is demagnetized; the permanent magnet 5 is used for orientation while being extruded, since the surface of the magnetic sheet 4 after orientation has been magnetized, and in the subsequent process, if the magnetic sheet 4 contains magnetism, There is a problem with the entire process, especially when it is cut. Since the cutting process is generally divided into a large cut and a small cut, when the large cut requires a small cut, all the magnetic sheets 4 are bonded together, and subsequent processes cannot be performed. Therefore, after the orientation, the magnetic force on the magnetic sheet 4 must be eliminated, i.e., demagnetized. In the present embodiment, the demagnetizing field 8 is used for demagnetization. As shown in FIG. 2, it is a schematic diagram of the magnetic field alignment at the time of orientation. Wherein the magnetic beam loop 12 is a closed loop, and the extrusion passage of the screw conveyor is a non-magnetic material; d. Roller rolling: The magnetic sheet 4 processed in step c is subjected to rolling using the rolling roller 7, and the extrusion force of the screw conveyor 3 is controlled to shape the magnetic sheet 4 into a desired thickness and density;

e. Cutting: 4 pieces of the original magnetic sheet are cut by a cutting machine 9 to be cut to form a strip-shaped heterodoid NdFeB composite magnetic strip of a desired size.

In this embodiment, the vulcanizing agent is dicumyl peroxide; the vulcanizing agent is triallyl isocyanurate; and the heat stabilizer is magnesium oxide.

In this embodiment, an isotropic NdFeB composite magnetic strip is prepared by a process such as kneading, mixing, spiral extrusion, orientation, roller rolling, and cutting. Among them, NdFeB magnetic powder can be produced by McGinn Magnetic Company, model number is MQA-38-14, magnetic powder characteristics are Br: 13. 1 KG, iHc : 14. 0 0e, (BH) max: 38 MG0e _o mixed The mixer also becomes an internal mixer. In this embodiment, the model X7101 produced by Nanjing Kaichi Machinery Co., Ltd. has a power of 110 kW and an output of 200 kg per hour. The function of the screw conveyor is to make the batch magnetic powder into a magnetic strip. Of course, there are many methods for making the magnetic sheet from the powder. Since the process must have an orientation step, the magnetic force can be adjusted by controlling the extrusion force of the screw conveyor. The density of the bars. Since the density of the magnetic strip is proportional to the orientation ratio, the final density of the oriented magnetic sheet is completed in the step of rolling down a plurality of rollers. Therefore, the process of rolling the roller can be divided into segments, so that several rollers are required to extend the roller. After testing, the magnetic properties of the prepared heterodyne-iron-boron-boron composite magnetic strip are: Remanence (Br): 7. 95 . 25 KG; Intrinsic coercivity (iHc): 8. 2^9. 2 0e _; maximum energy product (BH) raax: l l 7~13 , 2 MG0e.. The heterogeneous NdFeB composite magnetic strip can be made into a ring-shaped heterocyclic NdFeB composite magnet. Referring to Fig. 4 and Fig. 5, it can be divided into two different orientations of radiation and extreme alien. According to Embodiment 1, by the above method steps and the selection of the parameters in the method steps, a composite magnetic strip having a magnetic gas characteristic suitable for use in a generator and an electric motor is obtained. Example 2

The manufacturing process of the present heterogeneous NdFeB composite magnetic strip was identical to that of Example 1, except that trihydroxypropane trimethacrylate produced by Nanjing Jihua Lubricating Oil Co., Ltd. was used instead of triallyl isocyanurate. The characteristics of the heterocyclic NdFeB composite magnetic strip produced by this method were substantially the same as those of Example 1, but the vulcanizate produced was less odorous than that of Example 1. When the mixed magnetic powder is fed into a screw conveyor for extrusion, the extruded mixture is subjected to a flat die having a width of 400 mm and a thickness of 5 mmn, so that the extruded disk is 400 x 5 mm in size. The length is determined by the feeding of the screw machine.

Example 3

The heterogeneous NdFeB composite magnetic strip has a width of 400 mm and a thickness of 5 mm. Remanence (Br>: 7.95~8. 25 KG; iHc: 8. 2~9. 2 0e _; (BH): 11. 7~13. 2 G0e _o manufacturing method and the anisotropy in the first embodiment Iron-boron composite magnetic The strips are manufactured in the same way and will not be described in detail.

Example 4

The external-transmission type generator includes a rotor magnet, and the rotor magnet is made by using the hetero-island NdFeB composite magnetic strip in Embodiment 3.

Example 5

The externally-rotating generator includes a rotor magnet, and the rotor magnet is made of the hetero-nung NdFeB composite magnetic strip of Embodiment 3.

Example 6

The variable frequency ceiling fan motor comprises a rotor magnet, and the rotor magnet is made by using the heterogeneous neodymium iron boron composite magnetic strip in the third embodiment.

Example 7

Referring to Fig. 3, the present hub type generator includes a rotor magnet 14, and the rotor magnet 14 is made of the heterocyclic neodymium iron boron composite magnetic strip of the third embodiment. The rotor shell 13 and the stator are further included; the rotor magnet 14 is fixedly disposed in the hub 13 , and the hub 13 drives the magnet 14 to rotate synchronously; the stator includes a spindle 15 and a rotor magnet 14 fixedly mounted on the spindle 15 The claw pole stator 16 is disposed; the rotor magnet 14 is an annular strip-shaped heterodoid neodymium iron boron composite magnet. The hub member 13 is an aluminum forged wheel housing. The annular bar-shaped heterodagoned neodymium iron boron composite magnet, see Fig. 4 and Fig. 5, can be divided into two different orientations of radiation and polar anisotropy. The composite nanocrystal in the composite nanocrystalline neodymium iron boron magnetic strip means that the particle size of the powder is very fine and reaches the size of the nanometer.

In this embodiment, a heterocyclic NdFeB composite magnet having a ring-shaped strip is used instead of the conventional ferrite magnet anisotropic magnet, and the annular bar-shaped X-iron-boron-boron composite magnet can be integrally formed, and the thickness of the magnetic strip is uniform, and The magnet is closely attached to the aluminum shell of the hub, thus reducing the air gap between the stator and the efficiency of the variable frequency motor. It can easily reach the specification of 3W/6V at 15 km/h. Because the magnetic strip material has high characteristics, although the unit price per kilogram is higher than that of sintered ferrite anisotropic magnet, its weight is only sintered ferrite anisotropy. 1/3 of the magnet, the relative cost is not improved, but it saves the cost of the stator and the coil magnetic material. The one-piece heterogeneous NdFeB composite magnetic strip has a perfect curve, and there is no meal when riding a bicycle. The feeling of the rider can improve the comfort of the rider; and the heterogeneous NdFeB composite magnetic strip has a certain elasticity, and there is no danger of cracking on the bumpy road surface, which can improve the safety of the bicycle.

Claims

claims

1. A method for manufacturing anisotropic NdFeB composite magnetic strip, which is characterized by including the following steps:

a. Mixing: Put the NdFeB anisotropic magnetic powder, chlorinated polyethylene, vulcanizing agent, co-vulcanizing agent and heat stabilizer into the mixing machine (1) for mixing;

b. Batch mixing: Pour two or more batches of mixed magnetic powder into the mixing barrel (2), and mix in the mixing barrel to form mixed magnetic powder;

- c. Spiral extrusion tableting and orientation: The mixed magnetic powder after batch mixing is sent to the screw conveyor (3) for extrusion to form a magnetic sheet (4), and then passes through the orientation magnetic field (6) generated by the permanent magnet (5) ) Orient the magnetic sheet (4), and then demagnetize the oriented magnetic sheet (4);

d. Roller rolling: Use the rolling roller (7) to roll the magnetic sheet (4) processed in step c. At the same time, control the extrusion force of the screw conveyor (3) to shape the magnetic sheet (4). into the required thickness and density;

e. Cutting: The shaped magnetic sheet (4) is cut by the cutting machine (9) to form a strip-shaped isotropic NdFeB composite magnetic strip of the required size.

2. The manufacturing method of anisotropic NdFeB composite magnetic strip according to claim 1, characterized in that: in step a, a mass ratio of 92% NdFeB isotropic magnetic powder and 6% chlorinated Polyethylene, 0.9% vulcanizing agent, 0.3% co-vulcanizing agent and 0.8% heat stabilizer are put into the mixing machine (1) for mixing. The mixing time is 90 minutes. The temperature is controlled below 70°C.

3. The manufacturing method of isotropic NdFeB composite magnetic strip according to claim 1 or 2, characterized in that: the vulcanizing agent is dicumyl peroxide; the vulcanizing agent is triallyl isopropyl peroxide. Nitrile urate or trihydroxypropane trimethacrylate; the heat stabilizer is magnesium oxide.

4. An anisotropic NdFeB composite magnetic strip manufactured using the manufacturing method of the anisotropic NdFeB composite magnetic strip described in claim 3.

5. The anisotropic NdFeB composite magnetic strip as claimed in claim 4, characterized in that: the width of the anisotropic NdFeB composite magnetic strip is 400 μm and the thickness is 5 μm.

6. The anisotropic NdFeB composite magnetic strip according to claim 4 or 5, characterized in that: the magnetic properties of the anisotropic NdFeB composite magnetic strip are: residual magnetism (Br): 7.95~ 8. 25 KG; Intrinsic coercive force (iHc): 8. 2~9. 2 0e _; Maximum magnetic energy product (811) 111&: 11. 7~13. 2 MG0e.

7. An external-rotation motor, including a rotor magnet, characterized in that: the rotor magnet is made of the aisotropic NdFeB composite magnetic strip described in any one of claims 3-5.

8. An externally rotating generator, including a rotor magnet, characterized in that: the rotor magnet is made of the aisotropic NdFeB composite magnetic strip described in any one of claims 3-5.

9. A variable frequency ceiling fan motor, including a rotor magnet, characterized in that: the rotor magnet is made of the aisotropic NdFeB composite magnetic strip described in any one of claims 5-5.

10. A hub-type generator, including a rotor magnet, characterized in that: the rotor magnet is made of the aisotropic NdFeB composite magnetic strip described in any one of claims 5-5.