JP2000341916A - Magnet motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a strong static magnetic field, attain high output and low power consumption, and improve performance, by mounting a flexible magnet having a thermoplastic elastomer and rare earth magnet powder as an inevitable component in the final shape in a molding die while performing suitable axial magnetic field orientation as necessary, in a rotor frame. SOLUTION: An annular magnet motor has a drive winding 3 by fixing an armature core 2 to a base board 1, and a multi-pole magnetized annular magnet 7 is secured to a rotor frame 6 mounted to a rotary shaft 5. Here, rare earth magnet powder, thermoplastic polyurethane elastomer powder, calcium stearate powder, and hydrazine antioxidant are uniformly mixed by using a Henschel mixer(R), kneaded by an extruder and extrusion molded into plate shape, to obtain a thermoplastic polyurethane elastomer sheet containing the rare earth magnet powder. This plate-shaped sheet is heated, cooled, solidified in a compression molding form in an axial magnetic field, formed in a flexible magnet, and mounted as the annular magnet 7 in the stator frame 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-diameter magnet motor capable of satisfying demands for higher output and lower current consumption.

[0002]

2. Description of the Related Art FIG. 1 is a sectional view showing the configuration of an annular magnet motor having an output of less than W according to the present invention. In the figure, a substrate 1
An armature core 2 having a plurality of salient poles and a center hole is fixed to the armature. A driving coil 3 is wound around the salient poles, and a bearing 4 is inserted into the center hole. This bearing 4 allows the shaft 5
Are rotatably supported. The center hole of the rotor frame 6 is fixed to the upper end of the rotating shaft 5 protruding from the armature core 2. The rotor frame 6 surrounds the armature core 2, and a multipolar magnetized annular magnet 7 is fixed to the inner surface of the peripheral wall.

Conventionally, the above-mentioned annular magnet motor generally cuts a flexible sheet-like magnet composed of ferrite magnet powder and a binder into a band shape, curls it into an annular shape, and fixes it to the inner surface of the peripheral wall of the rotor frame. This is a configuration facing the salient pole surface of the child core. The ferrite magnet powder has a particle diameter of 3 μm.
Because of the following fine metal oxides, even when cut into strips, the magnet powder on the cut surface did not significantly affect the performance and reliability of the annular magnet motor. However, a flexible sheet magnet composed of ferrite magnet powder and a binder has a maximum energy product [BH] max of at most about 1.4 MGOe, which meets the demand for higher output and lower power consumption of a ring magnet motor. Therefore, it is important for the magnet to create a strong static magnetic field in the space facing the armature core.

By the way, a flexible sheet magnet composed of a rare earth magnet powder and a binder is cut into a band shape, curled into an annular shape, and fixed to the inner surface of the peripheral wall of the rotor frame. As a prior art of a magnet motor having an opposed configuration, Japanese Patent No. 2766746 discloses an Nd-Fe-
B-based, (Ce, La) -Fe-B-based magnet powder, natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, butyl rubber, ethylene propylene rubber, ethylene vinyl acetate rubber, nitrile rubber, acrylic rubber, urethane rubber, chloroprene One or two of the following groups: rubber, chlorosulfonated polyethylene, and polyethylene chloride
Select at least species, but 92-96 wt%, density 4.9-
A flexible sheet magnet with 5.8 g / cm ³ . Japanese Patent No. 2528574 discloses (a) R-Fe-B (R
Is a step of kneading an Nd / Pr) -based magnet powder and a binder,
(B) a step of rolling the kneaded material into a sheet shape after pulverizing the kneaded material;
A heat treatment at 0 ° C. for 60 to 180 mun. Furthermore, Utility Model No. 2
In Japanese Patent No. 528670, an armature core having salient poles and a coil wound thereon, and a flexible sheet-like magnet cut into a band shape, curled into an annular shape, and opposed to the salient pole surface of the armature core. A motor having an annular magnet, wherein the magnet is R-Fe-
B (R is Nd / Pr) based magnet powder, and the rolled surface of the magnet is opposed to the salient pole surface of the armature core, and the shear surface of the magnet cut surface is positioned on the armature side. Motor is disclosed.

However, 1. The density of the sheet magnet is 4.9
Limits of magnetic performance from ５5.8 g / cm ³ ,
2. The flexible binder is not in an essential state of adhesion with the rare earth magnet powder, and the magnetic attraction of the excited armature core causes the rare earth magnet powder to fall off and scatter, causing rotational noise and rotation failure. 2. Epoxy resin film treatment,
Processes are complicated, such as vulcanization of the flexible binder, reheating of the cut surface, and restriction of the cut surface when fixing to the rotor frame, and there is also a problem in reliability.

On the other hand, Japanese Patent Publication No. 6-87634 discloses a magnetically isotropic R-Fe-B (R is Nd / Pr) magnet for creating a strong static magnetic field in a space facing an armature core. Outer diameter of 25 mm or less composed of powder and binder, density 5 g /
An annular magnet motor having an annular resin magnet of cm ³ or more is disclosed. Magnetically anisotropic magnet powders have difficulty in achieving both small size and high output of the ring magnet motor because the degree of orientation decreases as the diameter of the ring magnet decreases.
If the magnetic powder is magnetically isotropic, it does not depend on the diameter of the annular magnet. For example, if the density is 6.2 to 6.3 g / cm ³ , the maximum energy product [BH] max11 to 12MG
Oe was reached, which was effective in increasing the output and reducing the current consumption of this type of annular magnet motor. For example, a thickness of 1.55 mm and a width of 7.5 composed of Sr ferrite magnet powder and a binder.
For a starting torque of 1.5 mN-m of an annular magnet motor, a 2 mm flexible sheet magnet is cut into a belt shape, curled, and fixed to the inner surface of the peripheral wall of a rotor frame having an inner diameter of 22.5 mm.
Compression molding of 22.5 mm in outer diameter, 1.10 mm in thickness, 9.4 mm in height, and 5.8 g / cm ³ in density composed of R-Fe-B (R is Nd / Pr) magnet powder and a binder The starting torque of the ring magnet motor having the ring magnet fixed to the rotor frame is 2
Reaches 0 mN-m. Further, as described in JP-B-6-42409, magnetically isotropic Fe-B
When an oligomer having an alcoholic hydroxyl group in the molecular chain such as a bisphenol-type epoxy which is solid at room temperature and a regenerated isocyanate are used as a binder for the R-based magnetic powder, R-Fe-B (R is Nd / Pr) The system magnet powder can be more firmly adhered and fixed.

The reason is that an isocyanate regenerated product is a product in which an active hydrogen compound is previously added to an isocyanate compound, and the isocyanate group is released by thermal dissociation, and the liberated isocyanate group reacts with an alcoholic hydroxyl group, and is crosslinked by urethane bond or the like. I do. At that time, a part of the released isocyanate group is R-Fe-B (R is Nd / Pr).
It reacts with the water adsorbed on the metal surface such as the system magnet powder to generate a substituted urea body, which forms a chelate bond with the metal oxide surface layer. Therefore, the magnet powder falls off,
It is considered to be the most effective conventional technology for increasing the output and lowering the current consumption of small-diameter annular magnet motors that are difficult to orient with a magnetic field without splattering and significantly affecting the performance and reliability of the annular magnet motor. . However, magnetically isotropic R-Fe-B
Since the magnetic performance of the resin magnet is restricted by its density and is strongly adhered and fixed with a thermosetting binder, there is a problem in recyclability.

[0008] Japanese Patent Application Laid-Open No. 5-299221 discloses that
The rare earth-iron-nitrogen magnet powder and the acid-modified styrene elastomer are kneaded / rolled, and the cut strip is curled to obtain a density of 5.6 g / cm ³ and a maximum energy product [such as used for a small motor]. BH] max
An annular magnet of 4.4 MGOe is disclosed. But,
The density of the magnetically isotropic R-Fe-B (R is Nd / Pr) -based magnet powder and the binder is 6.2 to 6.3 g / cm ³ , and the maximum energy product [BH] max is 11 to 12 MGOe. Compared with the ring-shaped resin magnet, the magnetic performance is inferior, and a strong static magnetic field cannot be obtained in the gap between the armature core. Further, the pinning type rare earth-iron-nitrogen based magnet powder is Sm ₂ Fe ₁₇ of several μm.
Chemically active due to fine powder consisting of N ₃ magnetic phase single phase,
Rare earth-iron-nitrogen magnet powder was exposed to the atmosphere on the cut surface, and there were problems such as permanent demagnetization due to oxidative corrosion and dropping and scattering of the magnet powder due to reduced adhesion to the styrene elastomer.

[0009]

Conventionally, a flexible sheet-like magnet generally composed of ferrite magnet powder and a binder is cut into a band, curled into an annular shape, and fixed to the inner surface of the peripheral wall of the rotor frame. 2. Description of the Related Art There is known a magnet motor configured to face a salient pole surface of an armature core. Since the ferrite magnet powder is a fine metal oxide having a particle diameter of 3 μm or less, even when cut into a strip, the magnet powder on the cut surface does not have a significant effect on the performance and reliability of the magnet motor. . However, a flexible magnet composed of ferrite magnet powder and a binder has a maximum energy product [BH] max of at most 1.4 MG.
It is about Oe, and in order to meet the demands for higher output and lower power consumption of the magnet motor, it is necessary for the magnet to create a strong static magnetic field in the space facing the armature core.

By the way, magnetically isotropic R-Fe-B
(R is Nd / Pr) A sheet-like magnet composed of a magnet powder and a flexible binder is cut into a band shape, curled in an annular shape, and fixed to the inner surface of the peripheral wall of the rotor frame. The magnet motor having the configuration facing 1. 1. Limitation of magnetic performance due to the density of the flexible magnet being 4.9 to 5.8 g / cm ³ ; The flexible binder is not in an essential bonded state with the rare earth magnet powder, and a part of the magnet powder is exposed to the atmosphere on the cut surface, and the rare earth magnet powder is excited by the magnetic attractive force of the excited armature core. 2. Problems of reliability such as falling off and scattering, causing rotation noise and rotation failure. There are drawbacks such as epoxy resin coating treatment, vulcanization of the flexible binder and reheating of the cut surface, and restriction of the cut surface when fixing to the rotor frame.

On the other hand, in order to create a strong static magnetic field in a space facing the armature core, a magnetically isotropic R-Fe-B
(R is Nd / Pr) A magnet motor composed of an annular resin magnet having an outer diameter of 25 mm or less and a density of 5 g / cm ³ or more composed of a magnet powder and a binder is strongly bonded and fixed to the magnet powder with a binder. Since the magnet powder can be formed, the magnet powder does not fall off and scatter, thereby not significantly affecting the performance and reliability of the magnet motor, and is most effective for increasing the output and reducing the current consumption of the small-diameter magnet motor. .2~6.3g / cm ^3, the maximum energy product [BH] max10~11MGOe is a limit, reduction in size and increase in output power further magnet motor, to meet the demand for low current consumption is come to the limit. Moreover, since the magnet powder is firmly adhered and fixed with a thermosetting binder, it has a drawback of difficulty in recycling.

Further, an anisotropic rare earth magnet powder and a flexible magnet
In the case of the stone, the rare earth-iron-nitrogen based magnet powder and acid-modified
Kneading / rolling the styrene elastomer, cutting it further
Curling of strips used for small motors
Density 5.6g / cm ^Three, Maximum energy product [B
H] max4.4MGOe annular magnet is disclosed.
You. However, magnetically isotropic R-Fe-B (R is Nd
/ Pr) Density of magnetic powder and binder 6.2 to 6.3 g
/ Cm^Three, Maximum energy product [BH] max11-12
Compared to MGOe's annular resin magnet, its magnetic performance is inferior.
A strong static magnetic field cannot be obtained in the gap with the armature core. Ma
In addition, the pinning type rare earth-iron-nitrogen magnet powder is several μm.
Sm_TwoFe₁₇N_ThreeChemistry for fine powder consisting of a single magnetic phase
Active, and rare-earth-iron-nitrogen-based magnet powder
Exposure to air, permanent demagnetization due to oxidative corrosion and styrene
Dropping and flying of magnet powder due to reduced adhesion to elastomer
There were issues such as scattering.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the prior art of the above-described magnet motor, and provides a strong static magnetic field to a space where a magnet and an armature core oppose each other to increase output and reduce power. It is an object of the present invention to provide a high-performance motor that promotes power consumption and maintains magnet reliability while improving recyclability of magnets.

In other words, the magnet motor of the present invention comprises a thermoplastic elastomer and a rare earth magnet powder as essential components, and performs injection or extrusion molding or calendering to cut the intermediate while axially orienting it as necessary. A magnet motor in which a flexible magnet having a final shape is formed in a molding die, and the flexible magnet is curled on a rotor frame and mounted as an annular magnet. Such a flexible magnet that does not finally have a cut surface can have an internal porosity of 2 vol% or less, so that the risk of the rare earth magnet powder being directly exposed to the atmosphere is extremely low, Permanent demagnetization due to oxidative corrosion and falling off of magnet powder can be prevented. As a preferable thermoplastic elastomer of the flexible magnet according to the present invention, for example, a bifunctional active hydrogen compound (for example, polyester) is used, and the isocyanate group and the active hydrogen group of the whole reaction system are equivalent to the linear polymer. Polyurethane elastomers. This kind of thermoplastic elastomer is usually in the form of pellets in many cases, but it is desirable to use a coarsely pulverized powder of, for example, 40 mesh or less in advance.

[0015] Polyurethane elastomers are classified into complete thermoplastic type elastomers and incomplete thermoplastic type elastomers. The former has less hygroscopicity than the latter and does not require post-curing to complete the reaction after molding. Also has excellent recyclability. The above-mentioned rare earth magnet powder to be kneaded with the thermoplastic elastomer is R-Fe-B (R is obtained by rapid solidification of a molten alloy, hot upsetting (Die-Up-Setting), or hydrogen decomposition / recrystallization (HDDR). Nd /
One or more types of Pr) -based magnet powder can be used. In particular, Nd, Fe, Co, B, Ga, and Zr-based magnet powder containing Dy subjected to hydrogen decomposition / recrystallization (HDDR), has a residual magnetization Jr at 20 ° C. of 11.5 kG or more and an intrinsic coercive force H _CJ of 14 kOe. The above R-Fe-B
When (R is Nd / Pr) -based magnet powder, a flexible magnet having a maximum energy product [BH] max of 18 MGOe or more can be easily obtained by an ordinary method such as injection molding, extrusion, and compression molding after calendering. it can.

Therefore, it is preferable for high output and low current consumption as a magnet motor. When the particle diameter of the rare earth magnet powder is set to 100 μm or less, the amount of magnetic flux between the magnetic poles at the time of multipolar magnetization can be homogenized, which is effective in reducing the torque ripple of the magnet motor. A flexible magnet having at least one side deformed is effective for reducing the cogging torque of the magnet motor.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The annular magnet motor of the present invention comprises a thermoplastic elastomer and a rare earth magnet powder as essential components, and is injected or extruded in a magnetic field as necessary, or is subjected to compression molding in a magnetic field as needed to obtain a final sheet. This is a magnet motor in which a flexible magnet having an internal porosity of 2 vol% or less and having no cut surface is curled and mounted on a rotor frame, for example.

Therefore, the flexible magnet in which the rare-earth magnet powder is highly filled, dispersed, oriented, and fixed in the thermoplastic elastomer of the present invention does not have a cut surface like a conventional flexible sheet magnet, and the surface thereof is It is covered with a thermoplastic elastomer rich layer, and the inside of the magnet is close to a voidless state with a porosity of 2 vol% or less. Therefore, an Nd-Fe-B system disclosed in Japanese Patent No. 2766746, (Ce, La)
-Fe-B based magnet powder, natural rubber, isoprene rubber,
Dispersion and orientation in one or more of butadiene rubber, styrene butadiene rubber, butyl rubber, ethylene propylene rubber, ethylene vinegar rubber, nitrile rubber, acrylic rubber, urethane rubber and chloroprene rubber, chlorosulfonated polyethylene, and polyethylene chloride Relative-earth magnet powder falls off and scatters due to the magnetic attraction of the armature core excited compared to fixing, causing rotational noise or rotational disturbance of the ring magnet motor, or reliability issues, or epoxy resin film Solves all issues such as processing, vulcanization of flexible binder and reheating of cut surface, restriction of cut surface when fixing to rotor frame, and also has recyclability of magnet because it is non-vulcanized ing.

Next, the rare earth magnet powder to be dispersed in the thermoplastic elastomer referred to in the present invention is 1-5SmCo,
Rare earth-cobalt magnet powders such as 2-17SmCo-based and rare earth-iron nitride magnet powders such as 2-17-3SmFeN are also applicable. However, from the viewpoint of the balance of resources from the viewpoint of the alloy composition of rare earth elements and transition metal elements, the magnetic potential specific to the magnet powder, suitability as a magnet motor, etc., preferred rare earth magnet powder is a rare earth-iron-based molten alloy rapidly solidified, Alternatively, one of R-Fe-B (R is Nd / Pr) -based magnet powder treated with hydrogen decomposition / recrystallization (HDDR)
Species or two or more species can be mentioned.

For example, in J.I. F. Herbest, "Rar
e Earth-Iron-Boron Materi
als; A New Era in Permanen
tMagnets "Ann. Rev. Sci. Vol-
16. Nd: F as described in (1986)
The molten alloy containing e: B in a ratio close to 2: 14: 1 is rapidly solidified and appropriately heat-treated to obtain N 2 having a crystal grain size of 20 to 50 nm.
A magnetically isotropic rare earth magnet powder having a residual magnetization Jr of about 8 kG and a specific coercive force H _CJ ≧ 8 kOe, in which a d ₂ Fe ₁₄ B phase is precipitated. Or R. Nakayama, T .; Take
shita et al; Magnetic prop
arties and microstructure
s of Nd-Fe-B magnetic powder
r-produced-by-hydrogen-tr
element. , J. et al. Appl. Phys. 70
(7) Hydrogen cracking / recrystallization (HDDR) treatment described in (1991), for example, alloy composition Nd _12.3 Dy
_0.3 Fe _64.7 Co _12.3 as B _6.0 Ga _{0. 6} Zr _0.1, generally at Dy0.25 atomic% or more, the residual magnetization Jr ≧ 11.5
It becomes a magnetically anisotropic magnet powder of kG and intrinsic coercive force H _CJ ≧ 14 kOe.

The maximum energy product [B] of a magnetically anisotropic flexible magnet in which one or more of these magnet powders are highly filled, dispersed, oriented and fixed in a thermoplastic elastomer.
H] max is 18 MGOe or more. Therefore, for example, a magnet motor of the present invention in which this flexible magnet is curled in a rotor frame in an annular shape is disclosed in Japanese Patent Publication No. 6-8763.
Patent Document 4 discloses a magnetically isotropic R-Fe-B
(R is Nd / Pr) or less outer diameter 25mm configured with a binding agent and magnet powder, the gap of the annular magnet motor of the configurations and density of 5 g / cm ³ or more annular resin magnet 140-150
% Of the static magnetic field can be generated, and the output of the magnet motor can be increased and the current consumption can be reduced.

The above R-Fe-B (R is Nd / P
The r) -based magnet powder may be a surface-treated powder such as carbon functional silane. The carbon functional silane is represented by the following formula.

YRSix _{3 wherein} Y is a hydrolyzing group, X is an organic functional group, R is an aliphatic residue, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltriethoxysilane,
N-β- (aminoethyl) -γ-aminopropyltriethoxysilane and the like are preferably used. The reason for performing such surface treatment is that the R-Fe-B (R is Nd / Pr) magnet powder is more reliably filled, dispersed, oriented, and adhered and fixed in a fluorine-containing thermoplastic elastomer. This is because a sheet magnet is used. Carbon functional silane treatment uses water in combination to promote the decomposition of hydrolyzable groups,
It is preferable to form a monomolecular film or more of carbon functional silane on the surface of the magnet powder using a lower alcohol as a solvent.

[0024]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the examples.

[Rare earth magnet powder] Alloy composition Nd ₁₂ Fe ₇₇
The molten alloy of Co ₅ B ₆ was rapidly solidified and crystallized. The residual magnetization Jr at 20 ° C. of the magnetically isotropic R—Fe—B (R is Nd / Pr) magnet powder A is 8.2 k each.
G, the intrinsic coercive force H _CJ was 9.4 kOe. On the other hand, Nd-Dy-Fe-Co-B-Ga-Zr alloy composition, N
A magnetically anisotropic R-Fe-B (R is Nd) obtained by subjecting a d-Fe-Co-B-Ga-Zr-based alloy to hydrogen decomposition / recrystallization treatment
/ Pr) Residual magnetization J at 20 ° C. of magnetic powders B ₁ to B ₅
r was 11.5 to 12.4 kG.

FIG. 2 shows the alloy composition Nd _12.3 Dy _0.3 Fe _64.6
Co _12.3 B _6.0 Ga _0.6 Zr _0.1 and Nd _13.3 Fe _62.5 C
The relationship between the particle diameter of o _17.0 B _6.8 Ga _0.3 Zr _0.1 and the intrinsic coercive force H _CJ is shown. B ₁ and B ₂ that do not contain Dy have a low specific coercive force H _CJ , and particularly a large decrease in the specific coercive force H _{CJ with} respect to a particle diameter of 100 μm or less.

[Flexible magnet] The above R-Fe-B (R is
Nd / Pr) magnet powders A and B₁~_FiveIn a nitrogen atmosphere
When coarsely pulverized to 105 μm or less, the specific surface area of A is
0.05-0.07 g / m^Two, B₁~_FiveIs 0.08-0.
09 g / m^TwoMet. Monolayer based on this specific surface area
In an amount to form γ-aminopropyltrimethoxysilane
(_TwoHN-C_ThreeH ₆-Si [OCH_Three]_Three, Specific gravity d_{twenty five}0 ° C.
94, molecular weight 221.3, monolayer coverage 332m^Two
/ G) was used. That is, for 100 g of magnet powder,
And γ-aminopropyltrimethoxysilane 0.002
2 g of -OCH_ThreeHydrolyze the group to form a -SiOH group
0.005 g of ion-exchanged water necessary for
Dilute with 0.243g, mix and heat to 130 ° C
Was. Then, by infrared spectroscopy (IR), -OCH_ThreeGroup absorption
Spectrum (ν_CH2845cm^-1) Disappears and -SiO
H group (ν_CH3350cm^-1)It was confirmed. That is, the book
The carbon functional silane treated rare
Earth magnet powder was used.

Next, the rare earth magnet powder A or B ₁
To _5, and a thermoplastic polyurethane elastomer powder pulverized to 40 mesh or less, a calcium stearate powder,
Hydrazine-based antioxidants were added at 92: 8.9: 0.0, respectively.
5: 0.05 (weight ratio), mixed until homogeneous using a Henschel mixer, melt-kneaded (210-230 ° C.) with an extruder, extruded into a 2 mmt plate, and mixed with rare earth magnet powder. A thermoplastic polyurethane elastomer sheet containing the body was obtained. Further, the plate-like sheet is
° C, and solidified by cooling in a compression mold (in an axial magnetic field of 15 kOe for anisotropic magnet powder), to give a final shape of 72 mm long, 4.9 mm wide and 0.5 mm thick. It was a flexible magnet. The porosity of each of these flexible magnets is 2
vol% or less.

FIG. 3 shows the specific coercive force H _CJ of a flexible magnet having an outer diameter of 5 mm and Pc-2.2, and 80 ° C. or 100 ° C. × 1.
The relationship of the irreversible demagnetization rate after hr is shown. Magnetically anisotropic R—Fe—B (R is Nd / Pr) magnet powder B ₁ to ₅ are magnetically isotropic R—Fe—B (R is Nd / Pr) magnet powder To obtain an irreversible demagnetization rate equivalent to that of body A, at least D
Intrinsic coercivity H _CJ 14 at 20 ° C. with alloy composition containing y
kOe or more is required.

FIG. 4 shows the 50k of the above typical flexible magnet.
A demagnetization curve at 20 ° C. after Oe pulse magnetization is shown in comparison with a ferrite rubber magnet. As shown in the figure, the maximum energy product [BH] max of the conventional ferrite rubber magnet is 1.
Only 4MGOe but was 7.7MGOe magnetically isotropic flexible magnet comprising magnetic powder A, a magnet powder B ₄ of anisotropic 18.5MGOe.

Next, a porosity of 2 vol% without the cut surface
The following flexible magnet was curled and mounted in an annular shape on the inner diameter of a rotor frame having an inner diameter of 23 mm to obtain the magnet motor of FIG.
(Table 1) shows the starting torque ratio when these magnet motors are driven at 12 V (starting torque 21.57 mN of the magnet motor in which the flexible magnet of the rare-earth magnet powder A is curled and mounted).
· M), and the rate of decrease in starting torque after heating in air at 100 ° C x 100 hr. In the table, Aa is a comparative example in which a ring magnet obtained by compression molding rare earth magnet powder A together with a solid epoxy resin at room temperature is mounted on a stator frame, and B ₄ b1 and B ₄ b2 are rare earth magnet powder B ₄
This is a comparative example in which a ring magnet (porosity of 3.8 vol% and 8.1 vol%, respectively) formed by compression molding with a liquid epoxy resin at room temperature in a radial magnetic field of 10 kOe is mounted on a stator frame.

[0032]

[Table 1]

Aa in Table 1 is obtained by compression molding rare earth magnet powder A together with a solid epoxy resin at room temperature.
With a 5 mm ring magnet, the pressure loss on the wall surface of the mold during compression is large, making high-density molding difficult, and as a result, the torque of the magnet motor is reduced. However, magnet motor A and B ₁ ~ ₅ according to the present invention are high torque compared to Aa. In particular, a magnet motor using anisotropic rare earth magnet powders B ₃ to B ₅ having an intrinsic coercive force H _{CJ of} 14 kOe or more, having no cut surface, and mounting a flexible magnet having a porosity of 2 vol% or less is about 140% high. It has the same thermal stability as the conventional magnet motor as well as the torque, and the rare earth magnet powder does not fall off and scatter due to the magnetic attraction of the excited armature iron core, causing no rotational noise or rotational disturbance.

However, B_Fourb1, B_FourRare earth like b2
Magnet powder B_FourWith a liquid epoxy resin at room temperature
Ring magnet compression molded in a radial magnetic field of 0 kOe
(The porosity is 3.8 vol% and 8.1 vol%, respectively)
The motor mounted on the stator frame has a radial magnetic field strength
, The degree of orientation is low, and the magnet motor B according to the present invention
_FourTorque is not so high, and the porosity is high.
Nd on stone powder surface_TwoFe₁₄Presumed to be due to oxidation corrosion of phase B
The torque reduction due to permanent demagnetization is large. The book
Since the invention is an axial magnetic field, if a strong orientation magnetic field can be obtained,
Not only in comparison to single molding with radial magnetic field orientation
There is an advantage that multiple molding can be performed simultaneously.

Further, increasing the torque generally increases the cogging torque of the magnet motor, but the flexible magnet according to the present invention reduces the gap distance from the armature core by, for example, deforming the stator surface. By adjusting the torque, the torque can be increased without increasing the cogging torque.

[0036]

As described above, the present invention comprises a rare earth magnet powder which is highly filled, dispersed, oriented and fixed in a thermoplastic elastomer, and has a maximum energy product of 18 MGOe or more at 20 ° C. and a magnetic stability in a practical temperature range. This is a magnet motor equipped with a flexible magnet having both flexibility, reliability and recyclability. Therefore, a strong static magnetic field can be generated in the gap with the armature core, which is effective for increasing the output of the magnet motor and reducing current consumption.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a magnet motor.

FIG. 2 is a characteristic diagram showing a relationship between a powder particle diameter and an intrinsic coercive force.

FIG. 3 is a characteristic diagram showing a relationship between an intrinsic coercive force and an irreversible demagnetization rate.

FIG. 4 is a characteristic diagram showing a demagnetization curve of a flexible magnet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Board 2 Armature core 3 Winding 4 Bearing 5 Rotation shaft 6 Rotor frame 7 Magnet

 ──────────────────────────────────────────────────の Continuing on the front page (72) Nao Hashimoto, Inventor 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Terms (reference) 5H622 AA03 CA01 CA05 CA10 DD02 DD04 DD05 PP05 PP17 PP20 QA02 QA03 QA04 QB05

Claims (8)

[Claims] 1. A flexible magnet without a cut surface, which comprises a thermoplastic elastomer and a rare earth magnet powder as essential components, and is cooled and solidified in a mold while being appropriately oriented in an axial magnetic field to obtain a final shape. Mounted magnet motor. 2. The magnet motor according to claim 1, wherein the flexible magnet is curled in an annular shape. 3. The magnet motor according to claim 1, wherein the porosity inside the flexible magnet is 2 vol% or less. 4. A rare earth magnet powder rapidly solidifies a molten alloy,
4. One, two or more kinds of R-Fe-B (R is Nd / Pr) magnet powder which has been hot-upset (Die-Up-Setting) or hydrogen-decomposed / recrystallized. The magnet motor as described. 5. Hot upsetting (Die-Up-Setti)
ng) or hydrogen cracked / recrystallized (HDDR) treated R
5. The magnet motor according to claim 4, wherein the intrinsic coercive force of the -Fe-B (R is Nd / Pr) magnet powder at 20 [deg.] C. is H _CJ 14 kOe or more. 6. The magnet powder subjected to hydrogen decomposition / recrystallization treatment contains Nd, Fe, 2.5% by atom or more of Dy as an essential component.
The magnet motor according to claim 5, wherein the magnet motor is a Co, B, Ga, Zr-based alloy. 7. The maximum energy product at 20 ° C. [B
7. The magnet motor according to claim 6, wherein a flexible magnet having a height H] of 18 MGOe or more is curled. 8. A flexible sheet-like magnet having at least one surface processed into a different shape, wherein the flexible sheet-like magnet has an annular shape.
The magnet motor as described.