Bonded magnet structure and motor

Abstract

The utility model relates to the field of bonded magnet structures, in particular to a bonded magnet structure and a motor, and the bonded magnet is characterized in that a hard glue layer with a certain thickness (greater than or equal to 3 microns) is uniformly covered on the outer surface of a bonded magnet body on the basis of not changing a bonded magnet material formula (the ratio of a binder to magnetic powder); the hard glue layer can effectively wrap the whole surface of the magnet and provide additional protection force for the magnet, so that the bonded magnet structure is not prone to fragmentation in the operation process, the bonded magnet structure can meet the requirements of some high-rotating-speed motors such as a high-rotating-speed blower and a high-rotating-speed dust collector, the effect is obvious, and application and popularization are convenient.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of bonded magnet structure, specifically relates to a bonded magnet structure and motor. BACKGROUND

[0002] Bonded magnet is the magnetic powder with certain permanent magnet performance and certain proportion of binder is mixed, and is made according to certain forming process.It is easy to control the size precision of the magnet with complex shape by using the bonding process, and the bonded magnet is widely used as the rotor in various motors.

[0003] The magnet inside the bonded magnet is guaranteed by the adhesion of the binder and the magnetic powder, and the internal binder content is less, and the mass ratio is about 2%-4% or so.The crack (tensile crack) strength of the magnet produced at present is insufficient, and cannot be applied to some high-speed motors (speed greater than or equal to 100000r / min). UTILITY MODEL CONTENTS

[0004] The utility model discloses a bonded magnet structure and a motor comprising the bonded magnet structure, and aims at the problem that the overall crack strength of the bonded magnet in the prior art is low and cannot meet the requirement of high-speed use of the motor, the bonded magnet structure is provided.The bonded magnet structure cancels the original magnet outer surface electrophoresis or sprays epoxy resin paint (as a protective layer) on the basis of not changing the bonded magnet material formula (binder and magnetic powder ratio), evenly covers a layer of hard glue layer with certain thickness on the outer surface of the magnet, the hard glue layer can effectively cover the magnet surface as a whole, provides additional protection for the magnet, so that the bonded magnet structure can be applied to some high-speed motors, such as high-speed hair dryer, high-speed dust collector and the like, the effect is obvious, and the utility model is convenient for popularization and application.

[0005] In order to realize the above-mentioned purpose, the utility model adopts the technical scheme that:

[0006] A bonded magnet structure, comprising a bonded magnet body, the outer layer of the bonded magnet body is covered with a hard glue layer, and the thickness of the hard glue layer is greater than or equal to 3um.

[0007] The bonded magnet structure provided by the utility model evenly covers a layer of hard glue layer with certain thickness (greater than or equal to 3um) on the outer surface of the bonded magnet body on the basis of not changing the bonded magnet material formula (binder and magnetic powder ratio), the hard glue layer can effectively cover the magnet surface as a whole, provides additional protection for the magnet, so that the bonded magnet structure can be applied to some high-speed motors, such as high-speed hair dryer, high-speed dust collector and the like, the effect is obvious, and the utility model is convenient for popularization and application.

[0008] As a preferred solution of the present invention, the bonded magnet body is a magnet obtained by mixing magnetic powder and a binder.

[0009] As a preferred solution of the present invention, the hard glue layer is prepared by spraying, dipping, brushing or rolling.

[0010] As a preferred embodiment of the present invention, the hard glue layer includes but is not limited to an epoxy resin glue layer, an acrylic resin glue layer, a phenolic resin glue layer or an amino resin glue layer.

[0011] As a preferred embodiment of the present invention, the thickness of the hard glue layer is 3um to 15um. Research has found that the thickness of the hard glue layer is a key factor affecting the technical effect. If the thickness of the hard glue layer is too low, the technical problem cannot be solved. Preferably, the thickness of the hard glue layer is 10um to 15um.

[0012] As a preferred solution of the present invention, the bonded magnet body is a neodymium iron boron magnet, a ferrite magnet, an aluminum nickel cobalt magnet or a rare earth cobalt magnet.

[0013] As a preferred solution of the present invention, the bonded magnet body is cylindrical, cylindrical, square, circular, sheet-like, arc-shaped or ring-shaped.

[0014] Another object of the present invention is to provide an electrode comprising the above-mentioned bonded magnet.

[0015] A motor comprises the above-mentioned bonded magnet structure.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0017] The bonded magnet structure provided by the utility model, on the basis of not changing the bonded magnet material formula (the ratio of binder to magnetic powder), uniformly covers the outer surface of the bonded magnet body with a hard glue layer with a certain thickness (≥3um), and the hard glue layer can effectively cover the entire surface of the magnet, providing additional protection for the magnet, making the bonded magnet structure less likely to break during operation, and more suitable for the needs of some high-speed motors, such as high-speed hair dryers, high-speed vacuum cleaners, etc., with obvious effects and easy to promote and apply. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic cross-sectional structural diagram of the bonded magnet structure provided in Example 1.

[0019] Figure 2 for Figure 1 Face it squarely.

[0020] Figure 3 forFigure 2 a top view of the embodiment 1.

[0021] Figure 4 a force analysis diagram for the experiment of the embodiment 2.

[0022] Icon: 1-bonded magnet body; 2-hard glue layer. DETAILED DESCRIPTION

[0023] The utility model will be described in detail below with reference to the drawings.

[0024] In order to make the purpose, technical scheme and advantage of the utility model more clearly, the utility model is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the utility model.

[0025] Embodiment 1

[0026] As shown in Figures 1-3 The application provides a cylindrical bonded magnet structure, specifically comprising a bonded magnet body 1, the outer layer of the bonded magnet body 1 is covered with a hard glue layer 2, and the thickness of the hard glue layer 2 is 10 um.

[0027] Among them, the bonded magnet body 1 is a magnet formed by mixing magnetic powder and a bonding agent.

[0028] In some examples, the hard glue layer 2 is prepared by spraying, dipping, brushing or rolling process. The bonded magnet body is a neodymium iron boron magnet, a ferrite magnet, an aluminum-nickel-cobalt magnet or a rare earth cobalt magnet. The bonded magnet body 1 is cylindrical, cylindrical, square, circular, sheet-shaped, arc-shaped or ring-shaped.

[0029] In some examples, the hard glue layer 2 includes but is not limited to an epoxy resin glue layer, an acrylic resin glue layer, a phenolic resin glue layer or an amino resin glue layer.

[0030] In some examples, the thickness of the hard glue layer 2 is 3 um to 15 um. Research has found that the thickness of the hard glue layer is a key factor affecting the technical effect, and the hard glue layer with too low thickness cannot solve the technical problem. Preferably, the thickness of the hard glue layer is 10 um to 15 um.

[0031] On the basis of not changing the formula of the bonded magnet material (the ratio of the binder to the magnetic powder), a hard glue layer 2 with a certain thickness (≥3um) is uniformly covered on the outer surface of the bonded magnet body 1. The hard glue layer 2 can effectively cover the magnet surface as a whole and provide additional protection for the magnet, so that the bonded magnet structure can be applied to some high-speed motors, such as high-speed hair dryers, high-speed vacuum cleaners, etc., the effect is obvious, and it is convenient for popularization and application.

[0032] The embodiment also provides an electric motor comprising the bonded magnet structure.

[0033] Embodiment 2

[0034] Embodiment 2 provides a specific operation process of the bonded magnet magnetic ring coated with the hard glue layer.

[0035] 1. Place the uncoated magnetic ring uniformly on the hanging fixture (the placement of the magnetic ring should be based on the height of the magnetic ring to select a suitable gap to ensure that all parts of the magnetic ring can be sprayed with glue).

[0036] 2. Pour the prepared glue to be sprayed into the glue spraying equipment, adjust the appropriate glue spraying angle and glue spraying flow, and perform the first glue spraying operation on the magnetic ring.

[0037] 3. After uniformly spraying the first surface, place the magnetic ring and the fixture in the high-temperature oven together to pre-dry the glue.

[0038] 4. After the pre-drying is completed, the magnetic ring is taken out together with the fixture, and the magnetic ring is turned over (the glue sprayed for the first time has been surface-dried), and after the turning over is completed, the second surface is sprayed according to step 1.

[0039] 5. After the second surface is sprayed, the magnetic ring and the placement fixture are placed in the high-temperature oven together to perform high-temperature curing of the glue.

[0040] 6. After the glue is high-temperature cured and cooled, a dense and hard glue layer will be formed, which completely covers the outer surface of the entire magnetic ring. The magnetic ring will be provided with an outer protective force, which is defined as f2.

[0041] Basic theory and experimental data analysis:

[0042] When the rotor rotates at high speed, the fragmentation is mainly caused by the centrifugal force (F) of the magnet being greater than the internal cohesive force (f1) of the magnetic ring and the protective force (f2) of the outer layer of the magnet.

[0043] The magnetic ring of certain specifications and quality has a constant centrifugal force at rated speed, and must satisfy f1+f2>F to avoid cracking during operation. Generally, the magnetic powder formula is fixed (i.e. the ratio of magnetic powder and binder) due to the requirement of material performance, and the binder content in the mixed powder is very low, so f1 is difficult to increase significantly, and only by increasing f2 can the magnetic ring operate at high speed without cracking.

[0044] The experiment can simulate the cracking of the magnetic ring by using a tapered auxiliary tool to slowly press into the inner diameter of the magnetic ring, and the press-stretching tester applies pressure downward until the magnetic ring is cracked by the auxiliary tool. The test obtains the down-pressing cracking force defined as f3. Figure 4

[0045]

[0046] F2 (magnetic ring transverse cracking force) = f3 / tan A Formula 1

[0047] At the moment of cracking of the magnetic ring, the transverse cracking force of the magnetic ring should exist: the internal cohesive force (f1) of the magnetic ring + the protective force (f2) of the outer layer of the magnetic ring.

[0048] That is, F2 = f3 / tan A = f1+f2 Formula 2

[0049] That is, f3 / tan A = f1+f2 Formula 3

[0050] f2 = f3 / tan A-f1 Formula 4

[0051] From the above formula and the structure of the magnetic ring, f1 is determined by the material of the magnetic ring and is a constant value, and angle A is related to the taper size of the auxiliary tool, which is also a constant value when the taper is consistent. Therefore, the protective force is in a positive proportional relationship with f3. The greater f3 is, the greater f2 is, so the protective force of the magnetic ring is greater and it is less likely to crack during operation.

[0052] The following table shows the test values of f3 (kgf) under different coating thicknesses under two coating conditions, and two auxiliary tools with different taper sizes are used for testing:

[0053] First group:

[0054] Electrophoretic coating thickness: 13 um

[0055] Glue coating thickness: 3 um

[0056] The specific data is shown in Table 1.

[0057] Table 1

[0058]

[0059] Second group:​​

[0060] Electrophoretic coating thickness: 13um;

[0061] Glue coating thickness: 5um;

[0062] The specific data are shown in Table 2.

[0063] Table 2

[0064]

[0065] Third group:

[0066] Electrophoretic coating thickness: 13um;

[0067] Glue coating thickness: 10um;

[0068] The specific data are shown in Table 3.

[0069] Table 3

[0070]

[0071] Fourth group:

[0072] Electrophoretic coating thickness: 13um;

[0073] Glue coating thickness: 15um;

[0074] The specific data are shown in Table 4.

[0075] Table 4

[0076]

[0077] The f3 obtained from the test is introduced into Formula 4, and the following can be obtained:

[0078] Electrophoretic coating thickness: 13um;

[0079] The protection of the electrophoretic coating product is f2(electric) = 683.62 - f1(kgf) Auxiliary 1 taper angle A1

[0080] f2(electric) = 677.33 - f1(kgf) Auxiliary 2 taper angle A2

[0081] Glue coating thickness: 3um;

[0082] The protection of the glue coating product is f2(glue) = 753.25 - f1(kgf) Auxiliary 1 taper angle A1

[0083] f2(glue) = 751.30 - f1(kgf) Auxiliary 2 taper angle A2

[0084] Glue coating thickness: 5um;

[0085] The protection of the glue coating product is: f2(glue)=775.88-f1(kgf) auxiliary 1 taper angle A1

[0086] f2(glue)=772.44-f1(kgf) auxiliary 2 taper angle A2

[0087] Glue coating thickness: 10um;

[0088] The protection of the glue coating product is: f2(glue)=856.78-f1(kgf) auxiliary 1 taper angle A1

[0089] f2(glue)=854.97-f1(kgf) auxiliary 2 taper angle A2

[0090] Glue coating thickness: 15um;

[0091] The protection of the glue coating product is: f2(glue)=982.14-f1(kgf) auxiliary 1 taper angle A1

[0092] f2(glue)=976.44-f1(kgf) auxiliary 2 taper angle A2

[0093] From the above formula, f1 is the same, the glue will provide greater protection f2 for the magnetic ring, and the thicker the hard glue coating, the greater the increased protection, that is, such products are less likely to break during the operation of the motor, and can better meet the needs of some high-speed motors.

[0094] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A bonded magnet structure, characterized in that: The invention comprises a bonded magnet body, wherein the outer layer of the bonded magnet body is coated with a hard glue layer, and the thickness of the hard glue layer is 3um to 15um; The hard glue layer is prepared by spraying, dipping, brushing or rolling.

2. The bonded magnet structure according to claim 1, characterized in that The hard glue layer is an epoxy resin glue layer, an acrylic resin glue layer, a phenolic resin glue layer or an amino resin glue layer.

3. The bonded magnet structure according to claim 1, wherein: The thickness of the hard glue layer is 10um to 15um.

4. The bonded magnet structure according to any one of claims 1 to 3, characterized in that: The bonded magnet body is a neodymium iron boron magnet, a ferrite magnet, an aluminum nickel cobalt magnet or a rare earth cobalt magnet.

5. The bonded magnet structure according to any one of claims 1 to 3, characterized in that: The bonded magnet body is cylindrical, columnar, square, circular, sheet-like, arc-shaped or ring-shaped.

6. A motor, characterized in that: The bonded magnet structure comprises the bonded magnet structure according to any one of claims 1 to 5.

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