JP4569139B2 - Rotor for IPM motor, method for manufacturing rotor for IPM motor using the same, and IPM motor therefor. - Google Patents

Description

  The present invention relates to an IPM motor using a permanent magnet, and more particularly to the rotor, a manufacturing method using the rotor, and the IPM motor.

An IPM motor (Internal Permanent Magnet: embedded permanent magnet type synchronous motor) is a motor that has been attracting attention for its energy saving effect because it can rotate at high speed because a permanent magnet is embedded in the rotor. 1) No brush, small and light, maintenance-free, 2) wide power control range, 3) low heat generation from the rotor, high efficiency, and 4) high torque even at high speeds. Recently, it has attracted attention (see, for example, Patent Document 1).
Hereinafter, a method for manufacturing the rotor of the IPM motor will be described with reference to the drawings.
There are two types of IPM motor rotor fabrication methods (FIGS. 8 and 9).
8 is a perspective view of a rotor for a sintered magnet type IPM motor according to Conventional Example 1. FIG.
In FIG. 8, 80 is a rotor for a sintered magnet type IPM motor, 81 is a rotor core, 82 is a shaft, 83 is a sintered magnet insertion hole, and 85 is a sintered magnet.
Thus, the rotor core 81 is provided with the sintered magnet insertion hole 83 for inserting the sintered magnet 85. The sintered magnet insertion hole 83 is formed between the sintered magnet 85 and the sintered magnet 85 when the sintered magnet 85 is inserted. The dimensions are tight so that no gaps are formed. Therefore, in order to insert the sintered magnet 85 into the sintered magnet insertion hole 83, it is necessary to adjust the size of the sintered magnet 85, and there is a drawback that it takes time to insert the magnet.

On the other hand, there is an injection molding method using a bonded magnet as Conventional Example 2 that solves the above-described drawback of time-consuming manufacturing.
FIG. 9 is a view showing a configuration of a bonded magnet type IPM motor rotor of Conventional Example 2.
In the figure, 70 is an IPM rotor according to Conventional Example 2, 71 is a rotor core, 72 is a shaft, and 73 is a bonded magnet hole into which a bonded magnet is inserted.
As described above, the rotor core 71 is provided with the bond magnet insertion holes 73 into which the bond magnets 75 are inserted (in four positions in the figure), and the bond magnets 75 are injected into the respective insertion holes 73. Then, the rotor 70 from which the bonded magnet 75 is injected is magnetized by a magnetizing apparatus shown in FIG.
FIG. 10 is a manufacturing process diagram of an IPM motor rotor that magnetizes the rotor of FIG.
In the figure, 70 is an IPM rotor according to Conventional Example 2, and 90 is a magnetizing device.
The magnetizing device 90 includes an orientation and magnetizing pole 92 and a magnetizing coil 93 for exciting the magnetizing poles 92 arranged on the yoke 91 on the circumference of the yoke 91 at intervals of 90 degrees. The rotor 70 is housed in a cylindrical hollow 90 so that the bond magnet 75 and the pole 92 are opposed to each other, and a current is passed through the magnetizing coil 93 to generate magnetic fluxes F and F ′. 75 is magnetized.
However, since the magnetic flux F ′ bypasses the bond magnet 75, it does not contribute to the magnetization of the bond magnet 75.
As described above, in this manufacturing method, the orientation magnetic field is weak, and the aimed magnetic characteristics cannot be obtained easily. In addition, since the magnetization magnetic field in the rotor of the IPM motor is not sufficient, sufficient magnetic characteristics cannot be obtained.
An IPM motor / rotor requires a residual magnetic flux density of 0.8 T or more and a maximum energy product of 110 kJ / m ³ or more, but such a numerical value cannot be obtained with the conventional IPM motor thus obtained. It was.
JP 2000-175389 A (page 5, FIG. 6)

As described above, in the conventional IPM motor manufacturing method, it is difficult to insert a magnet into the rotor by the sintered magnet insertion method, and in the injection molding method using the bonded magnet in consideration of these problems. The orientation magnetic field and the magnetizing magnetic field were weakened and the magnetic properties were lowered.
The present invention has been made in view of such problems, and adopts injection molding using a bonded magnet to facilitate insertion of the magnet in the IPM motor, and to strengthen the orientation magnetic field and the magnetization magnetic field. An object of the present invention is to provide a low-cost servo motor that can efficiently perform orientation in an IPM motor and thereby has a torque equivalent to that of a conventional motor.

In order to solve the above problem, the invention of the rotor for an IPM motor according to claim 1 is a rotor for an IPM motor, wherein a bond magnet hole into which an anisotropic bond magnet is inserted and the bond magnet hole are inserted. forming a magnetic pole insertion hole for inserting the pole for generating an orientation magnetic field and the magnetizing magnetic field to magnetize the bonded magnet therein, said bond magnet bore, formed side by side in a circumferential direction of the rotor, said pole insertion hole than said bonded magnet bore adjacent said be between bonded magnet holes adjacent to each other in the circumferential direction is arranged at a position closer to the center of the rotor, are disposed between the bonded magnet holes adjacent ones that the orientation of the magnetic pole to be inserted into the pole insertion hole, a magnetic flux generated by the magnetizing apparatus, through the pole from the bond magnet is inserted into one of the bonded magnet holes adjacent ones, other Characterized in that it coincides with the direction of the magnetic flux directed into said bonded magnet to be inserted into.
According to a second aspect of the present invention, in the rotor for an IPM motor according to the first aspect, the magnetic pole is a permanent magnet.
According to a third aspect of the present invention, in the rotor for an IPM motor according to the first or second aspect, the shape of the magnetic pole insertion hole is an arcuate shape, a square shape, a semicircle, a circle when viewed in a cross section passing through a direction perpendicular to the rotor axis. It is any one or more of these.
The invention of the method for manufacturing a rotor for an IPM motor according to claim 4 uses the rotor for an IPM motor according to any one of claims 1 to 3, and the bond magnet is inserted into the bond magnet hole by an injection molding machine. It is characterized by that.
The invention of the method for manufacturing an IPM motor rotor according to claim 5 uses the rotor for an IPM motor according to any one of claims 1 to 3, inserts the bond magnet into the bond magnet hole, and inserts the magnetic pole. insert the pole in the hole, characterized in that magnetizing the bonded magnet.
The invention of the IPM motor according to claim 6 is manufactured by the stator having a cylindrical space in the axial direction and the manufacturing method according to claim 4 or 5 inserted into the cylindrical space of the stator via a gap. And an IPM motor rotor.

With the above configuration, in an IPM motor using a permanent magnet, a magnetic pole insertion hole for inserting a magnetic pole for generating an orientation magnetic field and a magnetizing magnetic field is formed inside the rotor, and this is used for orientation and magnetization. As a result, the IPM motor has higher performance than the conventional method, which was manufactured without the orientation magnetic field and magnetization magnetic field generation source inside the rotor. can do.
Further, by arranging a magnetic pole insertion hole for generating an orientation magnetic field and a magnetizing magnetic field in the rotor in a direction closer to the center of the rotor than the magnet, a higher performance IPM motor can be manufactured.
A high-performance IPM motor can also be manufactured by making the shape of the magnetic pole insertion hole arcuate, circular, semicircular, or square.
In addition, a high-performance IPM motor can be easily manufactured by using an injection molding machine using a bond magnet for manufacturing the IPM motor.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram illustrating a configuration of an IPM motor rotor according to a second embodiment of the present invention.
In the figure, 10 is an IPM rotor according to the first embodiment, 11 is a rotor core, 12 is a shaft, and 13 is a bonded magnet hole into which a bonded magnet is inserted.
Reference numeral 14 denotes a magnetic pole insertion hole provided according to the present invention, which is used to insert a magnetic pole for generating an orientation magnetic field and a magnetization magnetic field inside the rotor, and is an arcuate magnetic pole insertion hole here.
The rotor core 11 is formed by laminating silicon steel plates to form a cylindrical shape as a whole. Bond insertion holes 13 into which bonded magnets that will eventually become permanent magnets are inserted are formed near this surface (in four places in the figure). ing.
The only difference between the IPM rotor 10 according to the first embodiment and the IPM rotor 10 of FIG. 9 is that an arcuate magnetic pole insertion hole 14 is provided in FIG.

FIG. 2 is a cross-sectional view taken along a direction perpendicular to the axis of a magnetizing apparatus used to magnetize the rotor as shown in FIG.
In the figure, 90 is a magnetizing device, 91 is a magnetizing yoke, 92 is a magnetizing pole, and 93 is a magnetizing coil. The magnetizing device 90 is formed by laminating magnetized yokes 91 of silicon steel plates to form a cylindrical shape as a whole, and the center thereof is a cylindrical hollow. Then, poles 92 (four in the drawing) that form magnetic poles extend from the circumference of the magnetizing yoke 91 toward the center, and a magnetizing coil 93 is wound around each pole 92. By energizing the magnetizing coil 93 in a predetermined direction, a magnetic field is generated in each pole 92 alternately from the inside of the pole to the outside of the pole or in the opposite direction.

FIG. 3 is a manufacturing process diagram of a rotor for an IPM motor that magnetizes the rotor of FIG. 1 according to Embodiment 1 of the present invention.
In the figure, the same reference numerals as those in FIG. 1 and FIG. Reference numeral 15 denotes a bonded magnet inserted into the bonded magnet hole 13, and reference numeral 16 denotes a magnetic pole (magnet) inserted into the magnetic pole insertion hole 14 provided according to the present invention.
Thus, the bond magnet 15 is inserted into the bond magnet hole 13 of the rotor 10 of FIG. An anisotropic SmFeN bonded magnet blended with nylon resin can be used as the bonded magnet. Insertion of the bond magnet 15 into the bond magnet hole 13 is preferably performed by an injection molding machine because the bond magnet 15 quickly and easily reaches every corner of the bond magnet hole 13. The feature of the present invention is that the magnetic pole 16 is inserted into the magnetic pole insertion hole 14. The direction of the magnetic pole 16 is adjusted so as to coincide with the direction of the magnetic flux passing through the vicinity thereof at the time of magnetization. Since there may be a clearance between the magnetic pole insertion hole 14 and the magnetic pole 16, the manufacture and insertion thereof can be performed easily.
The rotor 10 that has been inserted in this way is inserted into the cylindrical hollow of the magnetizing device 90 of FIG. 2, and the magnetizing coil 93 is energized in a predetermined direction, whereby the bond magnet 15 is magnetized.

  FIG. 4 is a diagram illustrating the direction of the magnetic flux F formed in the rotor of FIG. 1 according to the first embodiment of the present invention. In the figure, the magnetic flux F that has passed through one pole 92 from the outside to the inside is attracted to the magnetic pole 16, so that it inevitably passes through the bond magnet 15 in the middle, and most of the magnetic flux F is from the bond magnet 15. It can contribute to magnetization. Here, there is no magnetic flux F ′ bypassing from the pole 92 to the adjacent pole 92 without passing through the bond magnet 15 as shown in FIG. 9. Therefore, a high-performance IPM motor can be manufactured as compared with the conventional IPM motor.

Table 1 shows the characteristics of the bonded magnet thus manufactured.
In Table 1, according to Example 1, the residual magnetization Br (T), coercive force (iHc) (kA / m), and maximum energy product (BHmax) (kJ / m ³ ) of the bonded magnet are
Respectively,
(1) Residual magnetization Br (T) = 0.81 of the bonded magnet
(2) Coercive force (iHc) (kA / m) = 756,
(3) The maximum energy product (BHmax) (kJ / m ³ ) = 115.

Here, it compares with the prior art example 2 as a comparative example.
Comparative Example 1 is an IPM motor mounted with an anisotropic SmFeN bonded magnet manufactured according to FIG.
The residual magnetism, coercive force, and maximum energy product of the bond magnet are
Respectively,
(1) Residual magnetization Br (T) = 0.60 of the bond magnet,
(2) Coercive force (iHc) (kA / m) = 750,
(3) The maximum energy product (BHmax) (kJ / m ³ ) = 60.

  As can be seen from Table 1, there is no magnetic pole for generating magnetic flux in the rotor of Conventional Example 2, and since the orientation and magnetization are insufficient, both the residual magnetization and the maximum energy product are low. 1 shows that the residual magnetization and the maximum energy product of the bonded magnet are improved, which improves the torque of the IPM motor and enables high performance.

FIG. 5 is a diagram showing a configuration of an IPM motor rotor according to the second embodiment of the present invention.
In the figure, the same reference numerals as those in FIG. 1 and FIG. 20 is an IPM motor rotor according to the second embodiment, 141 is the same arcuate magnetic pole insertion hole as the first embodiment provided in the second embodiment, and the difference from the first embodiment is that the center of the shaft 12 is more than the first embodiment. The feature is that it has been moved toward, and the others are the same.

  The bond magnet 15 is inserted into the bond magnet hole 13 of the rotor 2 of FIG. 5 by an injection molding machine, and the magnetic pole 16 is inserted into the magnetic pole insertion hole 141. By inserting into the hollow and energizing the magnetizing coil 93 in a predetermined direction, the magnetic flux flows in the direction shown in FIG.

  FIG. 6 is a diagram illustrating the direction of the magnetic flux F formed in the rotor 20 according to the second embodiment. In the figure, since the magnetic flux F that has passed through one pole 92 from the outside to the inside is attracted to the magnetic pole 16, it inevitably passes through the bond magnet 15 in the middle. In this case, since the magnetic pole 16 is in the vicinity of the shaft 12, most of the magnetic flux F changes to the direction after proceeding to the vicinity of the shaft 12, and therefore passes through the center side from the end of the bond magnet 15. The results as shown in Fig. 1 were obtained.

In Table 1, according to Example 2,
(1) Residual magnetization Br (T) = 0.87 of the bonded magnet
(2) Coercive force (iHc) (kA / m) = 766,
(3) The maximum energy product (BHmax) (kJ / m ³ ) = 125.

  Thus, it can be seen that the residual magnetization and the maximum energy product of the bonded magnet are further improved as compared with the first embodiment. Therefore, the torque of the IPM motor is further improved, and further performance enhancement is possible.

FIG. 7 is a diagram showing a configuration of an IPM motor rotor according to the third embodiment of the present invention.
In the figure, the same reference numerals as those in FIG. 1 and FIG. Reference numeral 30 denotes an IPM motor rotor according to the third embodiment, and reference numeral 142 denotes a square magnetic pole insertion hole provided in the third embodiment. The difference from the first embodiment is that the magnetic pole insertion hole has an arcuate shape in the first embodiment, but here it is characterized by a square magnetic pole insertion hole, and the others are the same. By making the shape of the magnetic pole insertion hole 142 square, the manufacture of the hole and the manufacture of the magnetic pole became extremely easy as compared with Example 1, and the productivity was improved. Nevertheless, as shown in Table 1, it can be seen that the residual magnetization and the maximum energy product of the bonded magnet manufactured by Example 3 are comparable to Example 1.

In Table 1, according to Example 3,
(1) Residual magnetization Br (T) of the bonded magnet = 0.81 (Example 1 is also 0.81),
(2) Coercive force (iHc) (kA / m) = 753 (Example 1 is 756),
(3) The maximum energy product (BHmax) (kJ / m ³ ) = 115 (Example 1 is also 115).
Therefore, it has been found that even in this case, the torque of the IPM motor can be improved and high performance can be achieved.

  The shape of the magnetic pole insertion hole according to the present invention is not limited to the arcuate shape and the square shape, and may be a semicircle or a circle. In short, any hole may be used as long as a magnetic pole for generating a magnetic flux is inserted into the rotor 11.

  Thus, if the rotors 10 to 30 manufactured according to the present invention are inserted into the cylindrical space at the center of the stator manufactured by the same method as the conventional one, a concentrated winding type brushless DC motor can be configured, A motor that can rotate at high speed, has a large energy saving effect, has no brushes, is compact and lightweight, is maintenance-free, has a wide power control range, generates little heat from the rotor, and has high efficiency and high torque even at high speeds. It is done.

As described above, in an IPM motor using a permanent magnet, a magnetic pole insertion hole for inserting a magnetic pole for generating an orientation magnetic field and a magnetization magnetic field is formed inside the rotor, and this is used for orientation and magnetization. As a result, it is possible to secure a high-performance IPM motor as compared with the conventional method, which is manufactured in the absence of an orientation magnetic field and a magnetic field generation source in the rotor. I was able to.
Further, by arranging the magnetic pole insertion holes for generating the orientation magnetic field and the magnetizing magnetic field in the rotor in the direction closer to the center of the rotor than the magnet, it was possible to manufacture a higher performance IPM motor.
In addition, a high-performance IPM motor could be manufactured even if the shape of the magnetic pole insertion hole is an arc, a circle, a semicircle, or a square.
In addition, a high-performance IPM motor could be easily manufactured by using an injection molding machine using a bond magnet for manufacturing the IPM motor.

It is a figure which shows the structure of the rotor for IPM motors which concerns on Example 2 of this invention. It is sectional drawing cut in the direction orthogonal to the axis | shaft of the magnetizing apparatus used in order to magnetize a rotor. It is a manufacturing-process figure of the rotor for IPM motors which magnetizes the rotor of FIG. 1 which concerns on Example 1 of this invention. It is a figure which shows the direction of the magnetic flux F formed in the rotor of FIG. 1 which concerns on Example 1 of this invention. It is a figure which shows the structure of the rotor for IPM motors which concerns on Example 2 of this invention. It is a figure which shows the direction of the magnetic flux F formed in the rotor 20 which concerns on Example 2 of this invention. It is a figure which shows the structure of the rotor for IPM motors which concerns on Example 3 of this invention. It is a figure which shows the structure of the rotor for IPM motors of the prior art example 1 inserted by inserting a sintered magnet. It is a figure which shows the structure of the rotor for IPM motors of the prior art example 2 formed by injection-molding a bond magnet. FIG. 10 is a manufacturing process diagram of a rotor for an IPM motor that magnetizes the rotor of FIG. 9.

Explanation of symbols

10 IPM Motor Rotor 20 According to Embodiment 1 IPM Motor Rotor 30 According to Embodiment 2 IPM Motor Rotor 11 According to Embodiment 3 Rotor Core 12 Shaft 13, 15 Bond Magnet Hole 14 Magnetic pole Insertion Hole 141 of Embodiment 1 Implementation Magnetic pole insertion hole 142 of Example 2 Magnetic pole insertion hole 16 of Example 3 Magnetic pole (magnet) inserted into the magnetic pole insertion hole
90 Magnetizing device 91 Magnetizing yoke 92 Magnetizing pole 93 Magnetizing coil F Path of magnetic flux

Claims (6)

A rotor for an IPM motor,
A bonded magnet holes for inserting an anisotropic bonded magnet, a magnetic pole insertion hole for inserting the pole for generating an orientation magnetic field and the magnetizing magnetic field to magnetize the bonded magnet which is inserted into the bonded magnet bore, Formed inside,
The bond magnet holes are formed side by side in the circumferential direction of the rotor,
The magnetic pole insertion hole is disposed between bond magnet holes adjacent in the circumferential direction and at a position closer to the center of the rotor than the adjacent bond magnet hole,
Orientation of the magnetic pole to be inserted into the pole insertion hole disposed between the bonded magnet bore, wherein the adjacent, a magnetic flux generated by the magnetizing device, said to be inserted into one of the bonded magnet holes adjacent ones as the pole from the bond magnet, a rotor for an IPM motor, characterized in that coincides with the direction of the magnetic flux directed to the bond magnet which is inserted into the other.   The rotor for an IPM motor according to claim 1, wherein the magnetic pole is a permanent magnet.   3. The IPM according to claim 1, wherein the shape of the magnetic pole insertion hole is one or more of an arc shape, a square shape, a semicircle, and a circle when viewed in a cross section passing through a direction perpendicular to the rotor axis. Rotor for motor.   An IPM motor rotor manufacturing method using the IPM motor rotor according to claim 1, wherein the bond magnet is inserted into the bond magnet hole by an injection molding machine. Using the IPM motor rotor of any one of claims 1 to 3, that the bond inserting the bonded magnet in the magnet bore, to magnetize the bonded magnet by inserting the pole into the pole insertion hole A method of manufacturing a rotor for an IPM motor, which is characterized.   A stator having a cylindrical space in the axial direction, and a rotor for an IPM motor manufactured by the manufacturing method according to claim 4 or 5 inserted into the cylindrical space of the stator via a gap. An IPM motor characterized by comprising:

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