JP5660485B2 - Laminated magnet film mover - Google Patents

Description

The present invention relates to a minute laminated magnet film movable element applied to a rotary electric machine or the like, and more particularly to a laminated magnet film movable element having a laminated magnet film composed of a nanoscale crystal structure of a soft phase and a hard phase.

Regarding the reduction in size and weight of rotating electrical machines, for example, rotating electrical machines used for information communication equipment and the like have a market that is reduced in size and weight to a volume of about 40 mm ³ and a weight of 300 mg. The torque of these rotating electrical machines has a power approximation based on the scaling law in relation to the volume of the rotating electrical machine, and there is a significant torque drop. Therefore, the improvement of torque is strongly demanded in the rotating electrical machine targeted by the present invention, which is used as a driving source for advanced electrical and electronic equipment and robots in the fields of in-vehicle, information appliances, communication, precision measurement, medical welfare equipment. Yes.

For example, in Patent Document 1, a cylindrical main body having a conductive cylindrical wall provided with a slot is used as an excitation winding, and an intravascular ultra-longitudinal DC brushless motor having an outer diameter of 1 mm or less and a length of 2 mm or less is used. Applications for acoustic scanning systems are disclosed.

As a micro rotating electric machine according to the above, for example, an anisotropic bulk magnet mover is obtained by magnetizing an Nd ₂ Fe ₁₄ B sintered magnet, which has been subjected to electric discharge machining into a predetermined shape, with a pole pair number of 1 in the radial direction of an outer diameter of 0.76 mm. This is combined with a stator core to form a rotating electric machine (DC brushless motor) having an outer diameter of 1.6 mm and a length of 2 mm [see Non-Patent Document 1]. Alternatively, using an anisotropic bulk magnet mover configured as described above, H. Raisigel, M. Nakano, Ito et al., Outer diameter 6 mm, length 2.2 mm [see Non-Patent Document 2], outer diameter 5 There are known minute rotating electrical machines such as mm, length 1 mm [see non-patent document 3], and outer diameter 0.8 mm, length 1.2 mm [see non-patent document 4].

Regarding the anisotropic bulk magnet mover as described above, for example, after grinding an anisotropic Nd ₂ Fe ₁₄ B-based sintered magnet to an outer diameter of 0.9 mm, a sputtered film such as Dy and Tb is applied to the surface. The magnetic properties are recovered by surface modification that is formed and subjected to heat treatment to promote internal diffusion, and remanent magnetization Mr ≤1.35 T, coercive force HcJ = 1.34 MA / m, (BH) _max = 341 kJ / m ³ A bulk magnet mover is known [see Patent Document 2].

On the other hand, as an anisotropic magnet film instead of the anisotropic bulk magnet as described above, a magnet film having a thickness of 300 μm is known by a die upset method at 750 ° C. by D. Hinz et al. This anisotropic magnet film is said to have a remanent magnetization Mr = 1.25 T in the direction perpendicular to the plane, a coercive force HcJ = 1.06 MA / m, and (BH) _max = 290 kJ / m ³ [see Non-Patent Document 5]. Such a high Mr type magnet film is known to be used as an anisotropic magnet film mover for a minute rotating electric machine [see Non-Patent Document 6].

In addition, Topfer and T. Speliotis et al. Areotropically applied a Nd ₂ Fe ₁₄ B bonded magnet film with a residual magnetization of Mr 0.42 T, 15.8 kJ / m ³ , and a thickness of 500 μm, printed on a 10 mm diameter Fe-Si substrate. A magnetic membrane mover is used, and a micro electromechanical system (MEMS) motor having a torque of 55 μNm is used [see Non-Patent Document 7].
As described above, a wide range of magnetic properties in which the remanent magnetization Mr ranges from 0.42 to 1.35 T and various material forms from the magnet film to the bulk have been tried for the fine mover magnet.

Japanese National Publication No. 9-501820 JP 2005-210876

Sai Ohta, Takao Ohara, Yuki Karada, Munehisa Takeda, Mitsubishi Electric Technical Report Vol.75, pp.703-708 (2001). H. Raisigel, O. Wiss, N. Achotte, O. Cugat, J. Delamare, Proc. Of 18th Int. Workshop on high performance magnets and their applications, Annecy, France, pp.942-944, (2004). M. Nakano, S. Sato, R. Kato, H. Fukunaga, F. Yamashita, S. Hoefinger and J. Fidler, Proc. 18th Int. Workshop on High Performance Magnets and Their Applications, Annecy, France, pp.723- 726 (2004). Tetsuya Ito, Journal of Japan Society of Applied Magnetics, Vol.18, pp.922-927, (1994). D. Hinz, O. Gutfleisch and K. H. Muller, Proc. 18th Int. Workshop on High Performance Magnets and Their Applications, Annecy, France, pp. 76-83 (2004). F. Yamashita, M. Nakano, H. Fukunaga, Proc. 17th Int. Workshop on Rare-Earth Magnets and Their Applications, Newark, DE, US.pp. 668-674 (2002). Topfer, B. Pawlowski, D. Schabbel, Proc. Of 18th Int. Workshop on high performance magnets and their applications, pp.942-944, (2004).

By the way, the torque T of a rotating electrical machine equipped with a minute movable element having a diameter of 2 mm or less, which is the object of the present invention, is Pn as the number of pole pairs, I (Id, Iq) as current, and L (Ld, Lq as inductance). ) And the interlinkage magnetic flux is represented by Φa.
(Formula 1)
T = [Pn × Φa × Iq] + [Pn × (Ld-Lq) × Id]

Here, the first term on the right side is the magnet torque, and the second term is the reluctance torque. Note that the rotating electric machine targeted by the present invention has an outer diameter of the mover of approximately 2 mm or less. Due to such actual size restrictions, the laminated magnet film mover targeted by the present invention is mainly composed of a laminated magnet film and does not have a rotor core. The torque T generated by such a laminated magnet film movable element is only the magnet torque (Pn × Φa × Iq) of the first term on the right side, and there is no reluctance torque of the second term.

From Equation 1, the magnet torque is proportional to the number of pole pairs Pn, the interlinkage magnetic flux density Φa, that is, the gap magnetic flux density Φg, and the energization current I of the stator excitation winding. Further, the torque constant Kt (Nm / A) of the motor is a torque gradient with respect to the energization current I of the stator excitation winding, and the greater the Kt, the greater the rotational driving force and the easier the current control. Therefore, 1) Increase the number of pole pairs Pn as a means to suppress the torque decrease accompanying the miniaturization of the rotating electrical machine and further increase the rotational driving force and controllability by increasing Kt. 2) Increase the gap magnetic flux density Φg. 3) Increase the air gap permeance Pg to reduce the magnetic resistance. 4) Increasing the excitation current Iq or the number of turns n of the excitation winding may increase the excitation force on the stator side.

However, the outer diameter of the mover of the minute electric rotating machine targeted by the present invention is approximately 2.0 mm or less. In such a mover, for example, Patent Document 2 discloses an anisotropic Nd ₂ Fe ₁₄ B based sintered magnet having a residual magnetization Mr = 1.35 T, that is, an anisotropic bulk magnet mover having a high residual magnetization Mr. doing. However, when an anisotropic bulk magnet is applied to such a fine mover, there is a disadvantage that the number of pole pairs Pn is limited to 1.

Therefore, it is effective to increase the residual magnetization Mr of the magnet of the mover as means for increasing the torque of the rotating electric machine using the above-described minute anisotropic bulk magnet mover. However, in the mover disclosed in Patent Document 3, after anisotropic Nd ₂ Fe ₁₄ B-based bulk magnets are machined into a predetermined shape, Dy, Tb, etc. are formed on the surface by physical film forming means such as sputtering. The magnetic properties due to the deterioration of machining are recovered by heat treatment, and the remanent magnetization Mr is 1.35 T. In other words, with the magnet torque (Pn × Φa × Iq) of the first term on the right side in Equation 1 with the number of pole pairs Pn applied to the magnet set to 1, the residual magnetization Mr up to the theoretical limit of 1.6 T of the Nd ₂ Fe ₁₄ B intermetallic compound Assuming that the torque is increased, the torque improvement is less than 1.2 times.

On the other hand, as a high Mr type magnet film, a 300 μm thick magnet film of D. Hinz et al. Has a remanent magnetization Mr = 1.25 T in the direction perpendicular to the plane, a coercive force HcJ = 1.06 MA / m, (BH) _max = 290 kJ / m ³ is obtained [Non-Patent Document 5]. Such a magnet film is limited to application to an axial gap type rotary electric machine as an anisotropic magnet film mover.

By the way, as an example of a micro electric rotating machine as the object of the present invention, the relationship between the volume V mm ³ of a DC brushless motor of 100 mm ³ or less and the torque T mNm is a radial gap type and T = 3 × 10 ⁻⁴ x V ^1.0922 (correlation coefficient .9924), T in the axial direction gap type = 3x10 ^-6 x V ^1.9022 (correlation coefficient 0.9864), and the operation, power approximation holds in volume and torque of the same rotary electric machine structure.

For example, when comparing the torque in the radial gap type and the axial gap type rotary electric machine having a volume 100 mm ^3, respectively 45,19 μNm next, a strong torque rotary electric machine more than twice the radial gap structure occur Can be made. In other words, the anisotropic magnet film mover composed of an anisotropic magnet film having anisotropy in the direction perpendicular to the plane is a radial gap type rotary electric machine due to the structure of the rotary electric machine having a gap in the axial direction. Compared to this, the permeance is lowered. For this reason, it is difficult to increase the torque.

  On the other hand, when the isotropic bonded magnet film with residual magnetization Mr 0.42 T by screen printing of Topfer et al. And T. Speliotis et al. Is applied as an isotropic magnet film mover, a high Mr like remanent magnetization Mr = 1.35 T It remains below 40% of the gap magnetic flux density Φa of the radial gap-type rotary electric machine obtained from the anisotropic bulk magnet mover having For this reason, the rotating electrical machine of Topfer et al. Using an isotropic magnet film mover has a problem that a corresponding torque cannot be obtained unless the number of pole pairs Pn is significantly increased, such as 10 pole pairs. [Non-Patent Document 7].

The present invention relates to a minute laminated magnet film mover as applied to a minute radial gap type rotary electric machine.

(1) A solid or hollow isotropic magnet film with a diameter of 2 mm or less consisting of a nanoscale crystal structure of soft and hard phases, with a dimensional ratio L / D of 1 or more (where L is the direction of lamination) And a relative density RD of 85% or more, and includes a laminated magnet film having an arbitrary number of pole pairs in the in-plane direction. Movable child.

(2) The magnet film is obtained by rapid solidification of R-TM-B (R is Nd, Pr, TM is Fe, Co) -based molten alloy or Sm-Fe-based molten alloy,
Alternatively, R-TM-B (R is Nd, Pr, TM is Fe, Co) -based molten alloy or the Sm-Fe-based molten alloy is formed by physical deposition,
After that, they were crystallized or nitrided to develop hard magnetism,
The laminated magnet film mover as described in the item (1), comprising a soft phase of Fe-B or αFe and an R ₂ TM ₁₄ B system or Sm ₂ Fe ₁₇ N ₃ system hard phase.

(3) The magnet film
The Fe-B or αFe soft phase and R-TM-B (R is Nd, Pr, TM is Fe, Co) alloy or Sm-Fe alloy are physically deposited alternately and then crystallized. Or nitriding to develop hard magnetism,
The laminated magnet film mover according to item (1), comprising a soft phase of Fe-B and αFe and a hard phase of R ₂ TM ₁₄ B system or Sm ₂ Fe ₁₇ N ₃ system.

(4) The laminated magnet film movable element described in (2) or (3) , wherein the magnet film is a composite film to which a nonmagnetic film is added.

(5) the magnet film, the residual about 50% of the magnetization Mr is characterized by having a spring-back characteristics of the magnetization to recover more than 90% of the magnetization of the residual magnetization Mr be magnetization reversal (2) or ( The laminated magnet film movable element described in the item 3) .

(6) The magnet film has a remanent magnetization Mr 1 T or more in the in-plane direction, a coercive force HcJ 300 kA / m or more, and is multipolarly magnetized with a pole pair number of 2 or more in the in-plane direction. The laminated magnet film movable element described in (2) or (3) .

(7) The magnet film has a residual magnetization Mr 0.95 T or more in the in-plane direction, a coercive force HcJ 600 kA / m or more, and is multipolarly magnetized to have a pole pair number 4 or more in the in-plane direction. The laminated magnet film movable element described in (2) or (3) .

The rotary electric machine provided with the minute laminated magnet film mover according to the present invention can obtain a high torque, and can be used as a radial gap type DC brushless motor, a PM stepping motor, a generator, etc. The performance of various electrical and electronic equipment in the equipment field is improved.

(A) and (b) of FIG. 1 are conceptual diagrams showing nanoscale crystal structure forms of a soft phase and a hard phase in the present invention. FIG. 2 (a) is a diagram for explaining the definition of springback, and FIG. 2 (b) is a diagram for explaining its characteristic diagram. It is a characteristic view which shows the X-ray diffraction pattern of the magnet film of this invention. It is a conceptual diagram of a magnetic torque. 4 is a table 1 showing various characteristics of magnet films 1 to 6 and bonded magnets 1 to 4. 3 is a table 2 showing external magnetic fields and relative torque constants of magnet films 1 to 6 and bonded magnets 1 to 4. FIG. 6 is a characteristic diagram showing the relationship between the dimensional ratio L / D and the torque gradient dT / dHex of the laminated magnet film of the present invention.

First, an isotropic magnet film composed of a nanoscale crystal structure of a soft phase and a hard phase according to the present invention will be described.
R ₂ TM ₁₄ B (R is Nd of rare earth elements, or Pr, TM is Fe, Co of transition metal elements), R ₂ TM ₁₇ N ₃ (R is a hard phase constituting the magnetic film according to the present invention. Among rare earth elements, Sm and TM can be exemplified by Fe) among transition metal elements. When such a soft phase such as αFe having high saturation magnetization Ms exchange-coupled with the hard phase exists, magnetization is reversed first from the soft phase under a reverse magnetic field, and a high coercive force HcJ cannot be obtained. However, if the size of the soft phase is suppressed to be equal to or smaller than the domain wall width, nonuniform magnetization reversal in a reverse magnetic field is suppressed. As a result, the coercive force HcJ is dominated by the magnetic anisotropy Ha of the hard phase, and a decrease in the coercive force HcJ is suppressed. Furthermore, in order to obtain a higher magnetic flux from the soft phase, it is necessary to increase the volume ratio of the soft phase in the magnet. For this purpose, it is necessary to make the size of the hard phase as small as possible. The size of the hard phase may be equal to or smaller than the domain wall width, but if it is too small, it is difficult to maintain the coercive force HcJ. For this reason, it is suppressed to about the domain wall width. The domain wall width is estimated by π (A / Ku) 1/2, (A: exchange stiffness constant, Ku: magnetic anisotropy energy).

As a specific structure of the nanoscale crystal structure according to the present invention, when the soft phase is αFe and the hard phase is Nd ₂ Fe ₁₄ B as shown in FIG. And a magnetic film having a multilayer structure in which 10 ³ or more of hard phases 11 smaller than αFe are alternately deposited with soft phases 12. Alternatively, as shown in FIG. 1B, a configuration in which the soft phase 12 and the hard phase 11 in the range of 10 to 50 nm are randomly distributed can be exemplified. Such a magnet film is magnetically isotropic.

Furthermore, as the isotropic high Mr type magnet film having a remanent magnetization Mr 1 T or more of the configuration of FIG. 1A according to the present invention, αFe and Nd ₂ Fe ₁₄ B by PLD (pulse laser deposition) are Ta and the like. The magnetic film on the non-magnetic substrate can be exemplified [see H. Fukunaga, H. Nakayama, M. Nakano, M. Ishimaru, M. Itakura, and F. Yamashita, Intermag 2008, FG-06]. In addition, as an isotropic high Mt type magnet film having a remanent magnetization Mr 1 T or more with the configuration shown in FIG. 1B, a magnet film composed of three phases of FeB, αFe, and Nd ₂ Fe ₁₄ B by rapid solidification of a molten alloy is used. Illustrative examples are available [see Hirokazu Kanei, Satoshi Hirosawa, Journal of Japan Society of Applied Magnetics, vol.22, pp.385-387 (1998)]. Alternatively, as a high HcJ type magnet film, a magnet film of αFe and Pr ₂ Fe ₁₄ B can be exemplified [H. Yamamoto, K. Takasugi, F. Yamashita, Proc. 17th Int. Workshop on Rare-Earth Magnets and Their Applications, Newark, DE, US. Pp.307-314 (2002)].

By the way, the remanence enhancement of the magnetically isotropic magnet film consisting of a nanoscale crystal structure with the soft and hard phases adjusted to about 20 nm in FIG. 1 T or more. The coercive force HcJ reaches 400 kA / m. In particular, according to detailed computer analysis when sufficient magnetic coupling is given at the contact interface between αFe and R ₂ TM ₁₄ B, and the thickness of each is controlled to the nanoscale structure to the domain wall width, the crystal grain size If a uniform nanoscale crystal structure of about 10 nm is formed, the (BH) _max of a magnetically isotropic magnet film can be expected to be about 200 kJ / m ³ .

As described above, the magnet film according to the present invention is obtained by rapid solidification of an R-TM-B (R is Nd, Pr, TM is Fe, Co) -based molten alloy, Sm-Fe-based molten alloy, or the alloy is physically solidified. Film deposition by deposition method, or physically alternate Fe-B, αFe soft phase, R-TM-B (R is Nd, Pr, TM is Fe, Co) alloy, or Sm-Fe alloy After film formation, they are appropriately crystallized or nitrided as necessary to develop hard magnetism Fe-B, αFe soft phase, R ₂ TM ₁₄ B, or Sm ₂ Fe ₁₇ N ₃ hard phase And a nanoscale crystal structure. The magnet film may be a composite film in which a nonmagnetic material such as a nonferrous metal or an organic polymer is appropriately added as a protective film as necessary.

The laminated magnet film mover according to the present invention configured with an isotropic magnet film as described above has a dimension ratio L / D of 1 or more (however, L Is a laminated magnet film having a relative density of RD 85% or more, and then magnetized in the in-plane direction of the laminated magnet film. The reason why the diameter is limited to 2 mm or less is that the volume of the radial gap type rotary electric machine targeted by the present invention is approximately 100 mm ³ or less.

In addition, a plurality of isotropic magnet films with a diameter of 2 mm or less are laminated with a dimensional ratio L / D of 1 or more (where L is the length in the lamination direction and D is the diameter), and the relative density RD is 85% or more. The reason why it is a constituent element of the laminated magnet film is that the shape magnetic anisotropy of the laminated magnet film mover can be more effectively extracted when multipolar magnetization is performed in the in-plane direction of the laminated magnet film mover. .

Next, as a preferable characteristic of the magnetic film according to the present invention, the springback characteristic of magnetization will be described with reference to FIGS. First, the definition of the springback characteristic of magnetization referred to in the present invention will be described with reference to FIG. As shown in the figure, a demagnetizing field -H is applied from the residual magnetization Mr, and the magnetization is reversed to an arbitrary magnetization M. Thereafter, when the magnetization when the demagnetizing field -H is removed is Mr ', the magnetization reversal rate is (Mr-M) / Mr, and the magnetization restoration rate Mr' / Mr.

FIG. 2 (b) shows the magnetization reversal rate and recovery rate of an isotropic magnet film composed of a nanoscale crystal structure of a soft phase (Fe ₃ B, αFe) and a hard phase (Nd ₂ Fe ₁₄ B) according to the present invention. It is a characteristic view which shows a relationship. The comparative example is a single-phase magnet film having only a hard phase (Nd ₂ Fe ₁₄ B). As is apparent from the figure, the magnet film according to the example has a strong springback characteristic in which the magnetization of 90% or more of the residual magnetization Mr is recovered even when about 50% of the residual magnetization Mr is reversed. This is because such a spring back characteristic is effective in securing the demagnetization resistance of the laminated magnet film movable element when the rotating shaft is constrained for some reason in the micro rotating electric machine according to the present invention.

The magnet film as described above can exemplify the characteristics of the remanent magnetization Mr 1 T or more in the in-plane direction and the coercive force HcJ 300 kA / m or more. By using the laminated magnet film movable element, a radial gap type rotary electric machine such as a DC brushless motor can be obtained.

On the other hand, in the case where the residual magnetization Mr 0.95 T or more in the in-plane direction and the coercive force HcJ 600 kA / m or more, a multi-pole magnetized multi-layer magnetized mover with a pole pair number of 4 or more in the in-plane direction is used. It can be set as a radial direction rotary electric machine like this.

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

First, a surface of a Cu roll rotating at a peripheral speed of 30 m / sec through 10 g of argon alloy in a 10 MPa argon gas atmosphere with 10 g of molten alloy (alloy composition Nd4.5FebalCo5B18.5Cr2) loaded in a quartz crucible The amorphous film having a width of 2 mm and a thickness of 45 μm was rapidly solidified by discharging at 50 MPa.

Next, the amorphous film was subjected to heat treatment in a vacuum of 10 ⁻⁴ Torr at a heating rate of 200 ° C./min and 680 ° C. × 10 min. The magnetic characteristics after 4.8 MA / m pulse magnetization in the in-plane direction of the heat-treated film were remanent magnetization Mr 1.05 T and coercive force HcJ 330 kA / m.

Figure 3 is a characteristic diagram showing the X-ray diffraction pattern of the rapidly solidified _{Nd 4.5 Fe bal Co 5 B 18.5} Cr 2 magnet film described above crystallization. The magnetic film coercive force HcJ of 330 kA / m cannot be obtained unless the individual crystal grain size is in the range of 10 to 50 nm, and the soft phase (FeB, αFe) according to the present invention is shown in FIG. It can be seen that the film is an isotropic magnet film composed of a nanoscale crystal structure with a hard phase (Nd ₂ Fe ₁₄ B).

Next, a polyamide-based nonmagnetic film is added as a protective film to the isotropic magnet film according to the present invention, the diameter is about 1.63 mm, and an arbitrary dimensional ratio L / D (where L is the length in the stacking direction, D is a laminated magnetic film having an arbitrary relative density RD at 160 ° C. and a pressure of 10 MPa. Furthermore, a laminated magnet film, which is an essential component of the laminated magnet film movable element according to the present invention, was obtained by performing 4.8 MA / m pulse magnetization in the in-plane direction of the laminated magnet film.

On the other hand, the isotropic magnet film with the polyamide-based nonmagnetic film added thereto is made into a flaky pulverized product of 355 μm or less, which is compressed at 160 ° C. and 1000 MPa, and has an arbitrary density of about 1.63 mm in diameter and a dimensional ratio L / A bonded magnet with D was used. Furthermore, an isotropic bonded magnet which is an essential component of the mover as a comparative example of the present invention was obtained by performing 4.8 MA / m pulse magnetization in the radial direction of the magnet.

By the way, it is assumed that the magnet as the mover component magnetized with the pole pair number 1 in the in-plane direction as described above is exposed to a uniform external magnetic field Hex as shown in FIG. Here, if the counterclockwise direction of the rotation direction (magnetic torque generation direction) is positive, and the S pole center of Hex (corresponding to the rotating magnetic field from the stator) rotates counterclockwise from directly above the N pole of the magnet Think. Then, when the S pole center of Hex is directly above the N pole of the magnet, the torque is zero, and when the S pole center of Hex rotates counterclockwise, the magnetic torque gradually increases, at a position rotated 90 degrees. Maximum magnetic torque. When it further rotates, the magnetic torque gradually decreases again, and becomes zero at 180 degrees. Note that the torque measured by a magnetic torque meter using a magnet magnetized with one pole pair as a sample is equivalent to the torque in a rotating electric machine with one pole pair.

Table 1 shown in FIG. 5 is a characteristic that collectively shows torque measured with a magnetic torque meter with an external magnetic field Hex of 8 kA / m for each sample magnetized to a pole pair number of 1 including examples and comparative examples together with the history of the sample. It is a table.

Table 2 shown in FIG. 6 shows an example in which the external magnetic field Hex is changed, and torque for each sample magnetized to the pole pair number 1 including the comparative example, and torque with respect to the external magnetic field Hex corresponding to the torque constant of the rotating electrical machine. It is a characteristic table | surface which shows a gradient. However, each sample number corresponds to Table 1.

Meanwhile, the torque (M × Hex sin θ) with respect to the load angle θ in FIG. 4 corresponds to the magnet torque (Pn × Φa × Iq) in the first term on the right side of Equation 1. Here, Pn and Φa are applied to the sample, and Iq is applied to Hex. The dimensional ratio L / D and torque are linear functions with the origin as zero. Therefore, the torque at the dimensional ratio L / D = 1 in Table 1 was obtained by an extrapolation (interpolation) method from a linear expression connecting the torque and the origin at an arbitrary dimensional ratio L / D of each sample.

In addition, as shown in FIG. 7, when the torque gradient dT / dHex with respect to the external magnetic field Hex shown in Table 2 is the material form of the sample, that is, a film or flake powder, the origin of the dimensional ratio L / D is set as the origin. It is a linear function with zero. As shown in FIG. 7, when the material form is in-plane direction magnetization of a film or flaky powder, the gradient of the torque gradient dT / dHex with respect to the dimensional ratio L / D is different. That is, when the magnetization is in the same in-plane direction, the torque gradient dT / dHex of the film is more dependent on the dimensional ratio L / D than the flaky powder. This means that when the magnetization is in the same in-plane direction, the film has higher permeance than the flaky powder, and as a result, the demagnetizing field is small, so that it is not easily affected by the dimensional ratio L / D of the sample. In addition, the torque constant of the rotating electric machine using the laminated magnet film mover according to the present invention is 1.13 times that of a flaky powder having a thickness of 355 μm or less and a thickness of 45 μm, based on the ratio of the torque gradient dT / dHex between the two. .

When the essential component of the micro movable element targeted by the present invention is a bonded magnet, the coarse flaky powder having a thickness of 355 μm or less and a thickness of 45 μm as described above together with a binder is directly compression-molded. It is difficult to fill the cavity. Or application to injection molding materials is also difficult. Therefore, when the essential component of the minute mover is a bonded magnet, the flaky powder is adjusted to, for example, 150 μm or less. That is, when the laminated magnet film movable element according to the present invention and a bonded magnet obtained by solidifying flake-like powder with a binder are used as constituent elements of the movable element, the difference in torque constant between the rotating electric machines is further expanded.

By the way, the torque having the dimension ratio L / D = 2 in Table 1 shown in FIG. 5 is obtained from the slope of the linear expression with the origin of the dimension ratio L / D and the torque gradient dT / dHex being zero. When the dimensional ratio L / D of the sample is increased, the difference in the material form constituting the sample is reflected in the difference in the demagnetizing field. For this reason, the torque at the dimensional ratio L / D = 2 of the laminated magnet film, which is an essential component of the mover according to the present invention, is substantially equal to a value obtained by simply doubling the torque of L / D = 1. However, unlike the present invention, the torque of L / D = 2 of the sample in which the flaky powder is hardened is reduced by about 12% due to the difference in permeance (demagnetizing field) due to the difference in material form.

In addition, the magnetic torque ratios in Table 1 are values obtained by standardizing the dimensional ratio L / D = 1 and the magnetic torque of 2 based on a bond magnet (sample number Bond magnet 1) having a density of 5.88 Mg / m ³ . As shown in the table, in the case of the dimensional ratio L / D = 1, when the relative density RD of the laminated magnet film according to the present invention is 85% or more, the torque exceeding 120% on the basis of a bonded magnet having a density of 5.88 Mg / m ³ There is an increase.

The relative density RD of a bonded magnet obtained by compressing flaky powder together with a binder at about 1000 MPa is approximately 80%. In contrast, the laminated magnet film according to the present invention can easily make the level of the relative density RD 85% or more at a pressure of about 10 MPa.

11: Hard phase, 12: Soft phase

Claims (6)

A solid or hollow isotropic magnet film with a diameter of 2 mm or less consisting of a nanoscale crystal structure of soft and hard phases, with a dimensional ratio L / D of 1 or more (where L is the length in the stacking direction) , D is the diameter), and constitutes the relative density RD of 85% or more, and viewing including the laminated magnet film with any number of pole pairs in the plane direction,
The magnet film is obtained by rapid solidification of R-TM-B (R is Nd, Pr, TM is Fe, Co) -based molten alloy or Sm-Fe-based molten alloy,
Alternatively, an R-TM-B (R is Nd, Pr, TM is Fe, Co) -based molten alloy or the Sm-Fe-based molten alloy is formed into a film by physical deposition, and then crystallized or nitrided. A laminated magnet for a rotating electrical machine, characterized by comprising a soft phase of Fe-B or αFe that exhibits hard magnetism and an R ₂ TM ₁₄ B-based or Sm ₂ Fe ₁₇ N _3- based hard phase Membrane mover. A solid or hollow isotropic magnet film with a diameter of 2 mm or less consisting of a nanoscale crystal structure of soft and hard phases, with a dimensional ratio L / D of 1 or more (where L is the length in the stacking direction) , D is a diameter), and the relative density RD is configured to be 85% or more, and includes a laminated magnet film having an arbitrary number of pole pairs in the in-plane direction,
The magnet film is formed by alternately forming Fe-B or αFe soft phase and R-TM-B (R is Nd, Pr, TM is Fe, Co) -based alloy or Sm-Fe-based alloy alternately. , They are crystallized or nitrided to develop hard magnetism, Fe-B, αFe soft phase and R ₂ TM ₁₄ B system or Sm ₂ Fe ₁₇ N _Three A laminated magnet film mover for a rotary electric machine, characterized by comprising a hard phase of the system. 3. The laminated magnet film movable element according to claim 1, wherein the magnet film is a composite film to which a nonmagnetic film is added. The magnet film is about 50% of the residual magnetization Mr is claimed in claim 1 or 2 90% of the magnetization of the residual magnetization Mr be magnetization reversal is characterized by having a spring-back characteristics of the magnetization to recover Laminated magnet film mover. The magnet film has a remanent magnetization Mr 1 T or more in an in-plane direction, a coercive force HcJ 300 kA / m or more, and is multipolarly magnetized with a pole pair number 2 or more in the in-plane direction. The laminated magnet film movable element described in 1 or 2 . The magnet film has a residual magnetization Mr 0.95 T or more in the in-plane direction, a coercive force HcJ 600 kA / m or more, and is multipolarly magnetized with a pole pair number 4 or more in the in-plane direction. The laminated magnet film movable element described in 1 or 2 .