JP4704883B2 - Permanent magnet rotating electrical machine and cylindrical linear motor - Google Patents

Description

  The present invention relates to a cylindrical magnet used for a permanent magnet type rotating electrical machine or a cylindrical linear motor.

Permanent magnet type rotating electrical machines that use permanent magnets for the rotor are widely used in which a plurality of divided magnets are bonded to the periphery of the rotor core. In many cases, a cylindrical magnet is used. Since the cylindrical magnet is a single magnet, the number of parts is reduced, the assembly is facilitated, and the dimensional accuracy in the rotor assembly is also improved.
There are two types of anisotropy of cylindrical magnets: radial anisotropy and polar anisotropy. Radial anisotropy is a trapezoidal surface magnetic flux density distribution with a radial magnetization direction, and polar anisotropy is a magnetization direction in which adjacent different poles in a magnet are connected by a curve. Surface flux density distribution can be obtained. The recommended inner / outer diameter ratio of the cylindrical magnet is 0.75 to 0.95 for a radial anisotropic cylindrical magnet, and 0.6 to 0.8 for a polar anisotropic cylindrical magnet (for example, see Non-Patent Document 1). ).

Hitachi Metals, Ltd. "Nd-Fe-B high performance anisotropic ring magnet" 2003-9, HG-A18

In a cylindrical magnet used in a conventional permanent magnet type rotating electrical machine, in order to magnetize accurately in the anisotropic direction, the inner / outer diameter ratio needs to be within a limited range. For example, the inner / outer diameter ratio is When a radial anisotropic cylindrical magnet is 0.75 to 0.95 and a polar anisotropic cylindrical magnet is 0.6 to 0.8, a good cylindrical magnet is obtained. For this reason, there is a limit to increasing the radial thickness of the cylindrical magnet, and there is also a limit to increasing the magnetic flux density determined by the radial thickness of the permanent magnet and the gap length between the stator and the stator. .
For this reason, it has been difficult to increase the efficiency of permanent magnet type rotary electric machines and cylindrical linear motors using such cylindrical magnets by increasing the magnetic flux density.

  The present invention has been made to solve the above-described problems, and increases the radial thickness of a cylindrical permanent magnet used for a rotor so that the magnetic flux density of the permanent magnet type rotating electrical machine is increased. The purpose is to increase the efficiency and improve the efficiency. In addition, in a cylindrical linear motor using a cylindrical permanent magnet as a mover, the radial thickness of the cylindrical permanent magnet is increased to increase the magnetic flux density of the cylindrical linear motor and improve efficiency. Objective.

A permanent magnet type rotating electrical machine according to the present invention includes a rotor having a permanent magnet disposed on the outer periphery of a rotor core, and a stator, and the permanent magnet of the rotor has a plurality of cylindrical shapes. Permanent magnets are combined in the radial direction so that the inner peripheral surface of the outer cylindrical permanent magnet and the outer peripheral surface of the inner cylindrical permanent magnet are in close contact with each other. Alternatively, it is magnetized with circumferential anisotropy, and the inner / outer diameter ratio is 0.75 to 0.95 in the case of radial anisotropy, and 0.6 to 0.8 in the case of circumferential anisotropy. It is .

A cylindrical linear motor according to the present invention includes a mover having permanent magnets arranged on the outer periphery of a mover core so that N poles and S poles are alternately arranged in the axial direction, and a predetermined inner and outer portions. Combine a plurality of cylindrical permanent magnets that have a diameter ratio and are magnetized in a predetermined direction in the radial direction so that the inner peripheral surface of the outer cylindrical permanent magnet and the outer peripheral surface of the inner cylindrical permanent magnet are in close contact with each other. Thus, the permanent magnet of the mover is configured, and the plurality of cylindrical permanent magnets include cylindrical permanent magnets magnetized in the axial direction .

In the permanent magnet type rotating electrical machine according to the present invention, the permanent magnet of the rotor includes a plurality of cylindrical permanent magnets, and the inner peripheral surface of the outer cylindrical permanent magnet and the outer peripheral surface of the inner cylindrical permanent magnet are in close contact with each other. Each cylindrical permanent magnet is magnetized in the radial or circumferential anisotropy with the same number of magnetic poles, and the inner / outer diameter ratio is radial anisotropy. Is 0.75 to 0.95, and 0.6 to 0.8 in the case of circumferential anisotropy, so a plurality of cylindrical shapes can be obtained without increasing the individual radial thickness of each cylindrical permanent magnet. The radial thickness of the permanent magnet composed of permanent magnets can be increased. For this reason, the magnetic flux density can be increased to improve the efficiency of the permanent magnet type rotating electrical machine.

In the cylindrical linear motor according to the present invention, a plurality of cylindrical permanent magnets each having a predetermined inner / outer diameter ratio and anisotropically magnetized are used as the inner peripheral surface of the outer cylindrical permanent magnet and the inner cylinder. Combining in the radial direction so that the outer peripheral surface of the cylindrical permanent magnets are in close contact to constitute a permanent magnet of the mover , the plurality of cylindrical permanent magnets include cylindrical permanent magnets magnetized in the axial direction , Without increasing the individual radial thickness of each cylindrical permanent magnet, the radial thickness of a permanent magnet composed of a plurality of cylindrical permanent magnets can be increased. For this reason, the magnetic flux density can be increased and the efficiency of the cylindrical linear motor can be improved.

Embodiment 1 FIG.
A permanent magnet motor according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a permanent magnet motor according to Embodiment 1 of the present invention. As shown in the figure, the permanent magnet motor includes a stator 1 having a plurality of slots 1a formed on the inner peripheral side and a coil (not shown) mounted thereon, and a rotor 2, and is fixed to the rotor 2. The child 1 faces through the gap 3. The rotor 2 includes a shaft 4, a rotor core 5, and a cylindrical magnet (permanent magnet) 6 bonded around the rotor core 5, and the cylindrical magnet 6 has a plurality of stages (in this case, three stages). Cylindrical permanent magnets (first to third cylindrical permanent magnets 6a, 6b, 6c) are combined in the radial direction.

The rotor 2 of the permanent magnet type motor shown in FIG. 1 is shown in FIG. Three-stage cylindrical permanent magnets (first to third cylindrical permanent magnets 6a, 6b, 6c) are arranged in the radial direction from the inside to the outside, the first cylindrical permanent magnet 6a, the second cylindrical permanent magnet. The magnet 6b and the third cylindrical permanent magnet 6c are arranged in this order, and the inner peripheral surface of the outer cylindrical permanent magnet 6b (6c) and the outer peripheral surface of the inner cylindrical permanent magnet 6a (6b) are brought into close contact with each other by bonding or the like. ing. The cylindrical permanent magnets 6a to 6c are anisotropically magnetized at the stage of the individual cylindrical permanent magnets 6a to 6c before being combined in three stages, and in this case, the radial anisotropic (radial) is anisotropic. It is magnetized by sex.
The inner circumference radius of the innermost first cylindrical permanent magnet 6a is R1, the inner circumference radius of the second cylindrical permanent magnet 6b located in the middle is R2, and the innermost radius of the third cylindrical permanent magnet 6c is the innermost radius. The circumferential radius and the outer radius are R3 and R4, respectively, and the inner / outer diameter ratios R1 / R2, R2 / R3, and R3 / R4 of the cylindrical permanent magnets 6a, 6b, and 6c are about 0.8, for example. At this time, the inner / outer diameter ratio R1 / R4 of the cylindrical magnet 6 constituted by the three-stage cylindrical permanent magnets 6a to 6c is about 0.51.

As described above, there are two types of anisotropy of cylindrical magnets, radial anisotropy and polar anisotropy. However, in order to magnetize accurately in the anisotropy direction, the inner / outer diameter ratio is limited. It is necessary to be within the range. In general, a radially anisotropic cylindrical magnet magnetized in the radial direction has an inner / outer diameter ratio of 0.75 to 0.95, and a polar anisotropic cylindrical magnet magnetized in the circumferential direction has an inner / outer diameter ratio of 0.6 to When it is 0.8, a good cylindrical magnet is obtained.
In this embodiment, the cylindrical permanent magnets 6a to 6c having an inner / outer diameter ratio of about 0.8 and well magnetized in radial anisotropy are combined in three stages in the radial direction to form a cylindrical magnet of the rotor 2. 6 was configured. For this reason, the cylindrical magnet 6 of the rotor 2 has an inner / outer diameter ratio R1 / R4 of about 0.51, but is a well magnetized and highly reliable cylindrical magnet 6.
Thus, since the cylindrical magnet 6 of the rotor is configured by combining the cylindrical permanent magnets 6a to 6c in three stages in the radial direction, the cylindrical magnet 6 can have an inner / outer diameter ratio R1 / R4 of less than 0.75, that is, The radial thickness can be increased. Then, the magnetic flux density determined by the radial thickness and the width (gap length) of the gap 3 between the stator 1 is increased. When the magnetic flux density is improved, when the same torque is generated, the coil current of the stator 1 can be reduced, the copper loss is reduced, and the efficiency is improved.

In the above embodiment, the magnetization directions of the cylindrical permanent magnets 6a to 6c are set to radial anisotropy, but the inner / outer diameter ratio of the cylindrical permanent magnets 6a to 6c is set to 0.6 to 0.8. As an alternative, the magnetization direction may be circumferential anisotropy. In this case, for example, if the outer diameter of the rotor is φ100 mm and the inner / outer diameter ratio of each of the cylindrical permanent magnets 6a to 6c is 0.6, which is the minimum value, the inner diameter of the cylindrical magnet 6 is φ21.6 mm. On the other hand, when the cylindrical magnet 10 of the rotor 7 is composed of one cylindrical permanent magnet as in the conventional example shown in FIG. 3, when the inner / outer diameter ratio R6 / R5 is 0.6, the inner diameter is 60 mm. It becomes. In FIG. 3, 9 is the shaft of the rotor 7, and 10 is the rotor core.
The inner and outer diameter ratios of the cylindrical permanent magnets 6a to 6c may be different from each other as long as good magnetization can be achieved.

Embodiment 2. FIG.
In the first embodiment, the three-stage cylindrical permanent magnets 6a to 6c constituting the cylindrical magnet 6 of the rotor are all set in the same magnetization direction. In the second embodiment, as shown in FIG. The cylindrical magnet (permanent magnet) 11 of the rotor 2 is made using a plurality of (in this case, three) cylindrical permanent magnets (first to third cylindrical permanent magnets 11a, 11b, 11c) having different magnetization directions. Constitute. The first cylindrical permanent magnet 11a located on the innermost side is magnetized with circumferential anisotropy, and the third cylindrical permanent magnet 11c located on the outermost side is magnetized with radial anisotropy. Yes. The second cylindrical permanent magnet 11b located in the middle has a magnetization direction intermediate between the magnetization directions (circumferential direction and radial direction) of the cylindrical permanent magnets 11a and 11c on both sides.

By the way, if the plurality of cylindrical permanent magnets constituting the cylindrical magnet of the rotor are all magnetized in the radial anisotropy, the amount of magnetic flux interlinking the rotor core 5 increases and magnetic saturation occurs. Easy to do. When magnetic saturation occurs, the amount of magnetic flux does not increase, and even if the amount of permanent magnets in the rotor is increased, the gap magnetic flux density does not increase.
In this embodiment, the magnetization directions of the first to third cylindrical permanent magnets 11a, 11b, and 11c arranged in a combination of a plurality of stages are changed, and the amount of magnetic flux interlinking the rotor core 5 is reduced. Suppresses the occurrence of magnetic saturation. Thereby, when the usage-amount of the permanent magnet (cylindrical magnet 11) of the rotor 2 is increased, the gap magnetic flux density is improved, so that the permanent magnet can be used effectively.
Moreover, since the cylindrical magnet 11 of the rotor is configured by combining a plurality of cylindrical permanent magnets 11a to 11c in the radial direction as in the first embodiment, the cylindrical magnet 11 as a whole is in a good magnetized state. The radial thickness can be increased. For this reason, the magnetic flux density of a permanent magnet type motor can be increased and efficiency can be improved.

  In this embodiment, the innermost cylindrical permanent magnet 11a close to the rotor core 5 is magnetized in the circumferential anisotropy, thereby effectively reducing the amount of magnetic flux interlinking the rotor core 5. In addition, by magnetizing the outermost cylindrical permanent magnet 11c close to the gap 3 in the radial anisotropy, the gap magnetic flux density can be effectively improved.

Embodiment 3 FIG.
In the second embodiment, the magnetization directions of the cylindrical permanent magnets 11a to 11c are different from each other. However, as shown in FIG. 5, only the first cylindrical permanent magnet 11a located on the innermost side is in the circumferential direction. The other cylindrical permanent magnets 11b and 11c may be magnetized anisotropically in the radial direction.
Also in this embodiment, the amount of magnetic flux interlinking the rotor core 5 can be effectively reduced by magnetizing the innermost cylindrical permanent magnet 11a close to the rotor core 5 in the circumferential anisotropy. , The occurrence of magnetic saturation can be suppressed. Thereby, when the usage-amount of the permanent magnet (cylindrical magnet 11) of the rotor 2 is increased, the gap magnetic flux density is improved, so that the permanent magnet can be used effectively.

  As described above, if all the cylindrical permanent magnets constituting the cylindrical magnet of the rotor are all magnetized in the radial anisotropy, magnetic saturation is likely to occur. When the circumferentially anisotropic cylindrical permanent magnet is included, the amount of magnetic flux interlinking the rotor core 5 can be reduced, and there is an effect of suppressing the occurrence of magnetic saturation.

Embodiment 4 FIG.
In the fourth embodiment, as shown in FIG. 6, a cylindrical iron member 13 is inserted as an unmagnetized ferromagnetic body between two cylindrical permanent magnets 12a and 12b, and the rotor 2 A cylindrical magnet (permanent magnet) 12 is configured. The inner peripheral surface of the outer cylindrical permanent magnet 12 b and the outer peripheral surface of the inner cylindrical permanent magnet 12 a are brought into close contact via the iron member 13.
Generally, a permanent magnet motor using a cylindrical magnet as a rotor has a relatively small diameter and is often operated at a high speed. The inner and outer peripheral surfaces of the cylindrical magnet have poor surface dimensional accuracy at the time of manufacture compared to non-magnetized ferromagnetic materials such as iron. For this reason, the dimensional accuracy of a combination improves by arrange | positioning the iron member 13 with favorable dimensional accuracy between cylindrical permanent magnets as mentioned above. Thereby, the eccentricity of the cylindrical magnet 12 is suppressed, the rotation balance becomes good, and vibration and noise can be prevented.

  In this embodiment, the number of cylindrical permanent magnets 12a and 12b is two, but three or more cylindrical permanent magnets may be provided between each cylindrical permanent magnet.

Embodiment 5. FIG.
In the eighth embodiment, as shown in FIG. 7, a ring (can) 15 such as SUS or FRP is provided on the outermost periphery of the plurality of cylindrical permanent magnets 14a and 14b for preventing the scattering of the magnet. 2 cylindrical magnets (permanent magnets) 14 are formed.
As a result, it is possible to prevent the cylindrical permanent magnets 14a and 14b from being scattered due to cracks and chips, which is useful for the maintenance of the permanent magnet motor. In particular, since many permanent magnet motors using cylindrical magnets are small in size and small in diameter, they can generally be operated at high speed. However, the ring 15 can prevent scattering of magnets due to centrifugal force.

Embodiment 6 FIG.
In each of the above embodiments, as shown in FIG. 1, the stator 1 in which a coil is mounted on a stator core having a plurality of slots 1a is used. In this embodiment, as shown in FIG. A slotless motor in which a coil (not shown) is attached to the coil yoke (stator core) 1b, for example, is attached.
Permanent magnet motors that do not use a magnetic material near the air gap, such as slotless motors, have essentially small torque pulsation (cogging torque) when no current is applied and torque pulsation (torque ripple) when current is applied. It is often used for applications where a motor with a small speed fluctuation is required. Conventionally, in such a motor, the ratio of the length of the gap (distance between the rotor 2 and the coil yoke 1b) is generally large with respect to the radial thickness of the cylindrical magnet. Was low.
In this embodiment, the cylindrical magnet 6 (11, 12, 14) according to each of the first to fifth embodiments is applied to a slotless motor, and the radial thickness of the cylindrical magnet is increased. For this reason, an operating point can be improved effectively and magnetic flux density improves effectively. By improving the magnetic flux density, the coil current of the stator 1 necessary for generating torque can be reduced, the copper loss is reduced, and the efficiency is improved.

  Although the slotless motor is used in the above embodiment, the magnetic flux density can be effectively improved and the efficiency can be improved even if the coreless motor is used.

Embodiment 7 FIG.
Next, a cylindrical linear motor according to a seventh embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a cross-sectional view of a cylindrical linear motor according to Embodiment 7 of the present invention. As shown in the drawing, the cylindrical linear motor includes a stator 21 in which a coil (not shown) is wound around an inner peripheral side coil portion 34 and mounted, and a movable element 22. The child 22 and the stator 21 are opposed to each other through the gap 23. The mover 2 includes a shaft (axis) 24, a mover core 25, and a cylindrical magnet (permanent magnet) 26 bonded around the mover core 25. The cylindrical magnet 26 includes an N pole and an S pole. Are arranged alternately in the axial direction, and a plurality of (three in this case) cylindrical permanent magnets are also combined in the radial direction in the radial direction. In the cross-sectional view shown in FIG. 9, the first to third N-type cylindrical permanent magnets 26a, 26b, 26c) magnetized radially outward are combined to form an N-type cylindrical magnet 26A. Yes. The coils wound around the coil unit 34 are arranged in different phases sequentially in the axial direction. By energizing these coils with an appropriate phase, the cylindrical linear motor can move linearly.

The mover 22 of the cylindrical linear motor shown in FIG. 9 is shown in FIG. Three stages of N-type cylindrical permanent magnets (first to third N-type cylindrical permanent magnets 26a, 26b, and 26c) are arranged in the radial direction from the inside toward the outside. The second N-type cylindrical permanent magnet 26b and the third N-type cylindrical permanent magnet 26c are arranged in this order, and the inner peripheral surface of the outer N-type cylindrical permanent magnet 26b (26c) and the inner N-type cylindrical permanent magnet 26c. The outer peripheral surface of the magnet 26a (26b) is adhered by adhesion or the like. Each of the N-type cylindrical permanent magnets 26a to 26c is magnetized in the N-type at the stage of the individual cylindrical permanent magnet before being combined in three stages.
Moreover, the case where the cross section of the needle | mover 22 is the S-type cylindrical magnet 26B is shown in FIG. The cylindrical magnet 26 of the mover 22 is configured by alternately arranging the N-type cylindrical magnet 26A and the S-type cylindrical magnet 26B shown in FIG. 10 in the axial direction. As shown in FIG. 11, three stages of S-shaped cylindrical permanent magnets (first to third S-shaped cylindrical permanent magnets 26d, 26e, 26f) magnetized inward in the radial direction are radially From the inside toward the outside, the first S-shaped cylindrical permanent magnet 26d, the second S-shaped cylindrical permanent magnet 26e, and the third S-shaped cylindrical permanent magnet 26f are arranged in this order, and the outer S-shaped cylindrical permanent magnet 26f is arranged in this order. The inner peripheral surface of the magnet 26e (26f) and the outer peripheral surface of the inner S-shaped cylindrical permanent magnet 26d (26e) are adhered by adhesion or the like. Each of the S-shaped cylindrical permanent magnets 26d to 26f is magnetized in the S-shape at the stage of the individual cylindrical permanent magnet before being combined in three stages.

  The inner peripheral radius of the innermost first cylindrical permanent magnets 26a, 26d is R1, the inner peripheral radius of the second cylindrical permanent magnets 26b, 26e located in the middle is R2, and the outermost third cylindrical permanent magnet. The inner and outer radii of the magnets 26c and 26f are R3 and R4, respectively, and the inner / outer diameter ratios R1 / R2, R2 / R3 of the first to third cylindrical permanent magnets 26a (26d) to 26c (26f), respectively. R3 / R4 is, for example, about 0.8. At this time, the inner / outer diameter ratio R1 / R4 of the cylindrical magnet 26 constituted by the three-stage cylindrical permanent magnets 26a (26d) to 26c (26f) is about 0.51.

In order to magnetize the cylindrical magnet with high accuracy, the inner / outer diameter ratio needs to be within a limited range, and there is a limit to reducing the inner / outer diameter ratio (inner diameter / outer diameter). In this embodiment, each cylindrical permanent magnet 26a (26d) to 26c (26f) magnetized well is combined in three stages in the radial direction to constitute the cylindrical magnet 26 of the mover 22. For this reason, the cylindrical magnet 26 of the mover 22 can reduce the inner / outer diameter ratio R1 / R4, and becomes a highly reliable cylindrical magnet 26 that is well magnetized.
Thus, since the cylindrical magnet 26 of the mover 22 is configured by combining the cylindrical permanent magnets 26a (26d) to 26c (26f) in three stages in the radial direction, the cylindrical magnet 26 reduces the inner / outer diameter ratio R1 / R4. In other words, the radial thickness can be increased, and the magnetic flux density of the gap 23 is increased. When the magnetic flux density is increased, when the same thrust is generated, the coil current of the stator 21 can be reduced, the copper loss is reduced, and the efficiency is improved.

Embodiment 8 FIG.
In the seventh embodiment, the three-stage N-type cylindrical permanent magnets 26a to 26c (S-type cylindrical permanent magnets 26d to 26f) constituting the N-type cylindrical magnet 26A (S-type cylindrical magnet 26B) of the mover 22 are used. The magnetization direction is the same radially outward (radially inward). In the eighth embodiment, as shown in FIG. 12, a plurality (in this case, three stages) of N-type cylindrical permanent magnets having different magnetization directions (first to third N cylindrical permanent magnets 27a, 27b, 27c). ) To form an N-type cylindrical magnet (permanent magnet) 27A of the mover 22. In addition, although illustration is abbreviate | omitted, also about the S type cylindrical magnet 27B, the magnetization direction of a three-stage S type cylindrical permanent magnet shall be different.
The first N-type cylindrical permanent magnet 27a located on the innermost side is magnetized in the axial direction, for example, upward, and the third N-type cylindrical permanent magnet 27c located on the outermost side is magnetized outward in the radial direction. It is magnetized. The second N-type cylindrical permanent magnet 27b located in the middle has a magnetization direction intermediate between the magnetization directions (circumferential direction and radial direction) of the N-type cylindrical permanent magnets 27a and 27c on both sides.

By the way, a plurality of N type cylindrical permanent magnets 26a to 26c (S type cylindrical permanent magnets 26d to 26f) constituting the N type cylindrical magnet 26A (S type cylindrical magnet 26B) of the mover 22 are all attached in the radial direction. When magnetized, the amount of magnetic flux interlinking the mover core 25 increases, and magnetic saturation is likely to occur. When magnetic saturation occurs, the amount of magnetic flux does not increase, and even if the amount of permanent magnets of the mover 22 is increased, the gap magnetic flux density does not increase.
In this embodiment, the magnetization directions of the first to third cylindrical permanent magnets 27a to 27c (27d to 27f) arranged in combination in a plurality of stages are changed, and the amount of magnetic flux that links the mover core 25 is changed. Reduce the occurrence of magnetic saturation. As a result, when the amount of permanent magnet (cylindrical magnet 27) used in the mover 22 is increased, the gap magnetic flux density is improved, so that the permanent magnet can be used effectively.

FIG. 13 shows a part of the axial section of the mover 22. As described above, the first N-type cylindrical permanent magnet 27a (S-type cylindrical permanent magnet 27d) located on the innermost side is magnetized in the axial direction, and the third N-type cylindrical shape located on the outermost side. The permanent magnet 27c (S-shaped cylindrical permanent magnet 27f) is magnetized in the radial direction. Thereby, as shown by the arrows in the figure, it can be seen that a U-shaped magnetic flux is formed which turns inward from the stator side toward the outer side, and the amount of magnetic flux interlinking the mover core 25 can be reduced.
Moreover, since the cylindrical magnet 27 of the mover 22 is configured by combining a plurality of cylindrical permanent magnets 27a to 27c (27d to 27f) in the radial direction as in the seventh embodiment, as the entire cylindrical magnet 27, The thickness in the radial direction can be increased in a good magnetized state. For this reason, the magnetic flux density of a cylindrical linear motor can be increased and efficiency can be improved.

  As shown in FIG. 14, the axial position of the first N-type cylindrical permanent magnet 27a (S-type cylindrical permanent magnet 27d) located on the innermost side is set with respect to the other outer cylindrical permanent magnets. When arranged in a shifted manner, it becomes easier to form a U-shaped magnetic flux that turns inward from the stator side and goes outward, and the effect of reducing the amount of magnetic flux interlinking the mover core 25 is enhanced.

Embodiment 9 FIG.
In the eighth embodiment, the magnetization directions of the plurality of N-type cylindrical permanent magnets 27a to 27c (S-type cylindrical permanent magnets 27d to 27f) are different from each other. However, as shown in FIG. The first cylindrical permanent magnet 27a (27d) located inside may be magnetized in the axial direction, and the other cylindrical permanent magnets 27b (27e) and 27c (27f) may be magnetized in the radial direction.
Also in this embodiment, by magnetizing the innermost cylindrical permanent magnet 27a (27d) close to the mover core 25 in the axial direction, the amount of magnetic flux interlinking the mover core 25 can be effectively reduced. , The occurrence of magnetic saturation can be suppressed. As a result, when the amount of permanent magnet (cylindrical magnet 27) used in the mover 22 is increased, the gap magnetic flux density is improved, so that the permanent magnet can be used effectively.

  In addition, each magnetization direction of the 1st-3rd cylindrical permanent magnets 27a-27c (27d-27f) arrange | positioned in multiple steps combination is not restricted to the said Embodiment 8, 9, but is located relatively outside. The magnetization direction of the cylindrical permanent magnet to be used may be the radial direction, and the magnetization direction of the cylindrical permanent magnet positioned relatively inside may be the axial direction, and the amount of magnetic flux interlinking the mover core 25 can be reduced.

  In the above embodiment, the magnetized in the axial direction may be accompanied by a gradient in the radial direction, and the cylindrical permanent magnet constituting the N-type cylindrical magnet 27A has a gradient in the radially outward direction. The cylindrical permanent magnet constituting the S-shaped cylindrical magnet 27B is inclined radially inward.

Embodiment 10 FIG.
In the tenth embodiment, as shown in FIG. 16, a cylindrical iron member 29 is inserted as a non-magnetized ferromagnetic material between two cylindrical permanent magnets 28a and 28b arranged in the radial direction. Thus, a cylindrical magnet (permanent magnet) 28 of the mover 22 is configured. The inner peripheral surface of the outer cylindrical permanent magnet 28 b and the outer peripheral surface of the inner cylindrical permanent magnet 28 a are brought into close contact via the iron member 29.
Thus, the dimensional accuracy of a combination improves by arrange | positioning the iron member 13 with favorable dimensional accuracy between cylindrical permanent magnets. Thereby, the eccentricity of the cylindrical magnet 28 is suppressed, the balance becomes good, and vibration and noise can be prevented.

  In this embodiment, two cylindrical permanent magnets are arranged in the radial direction, but three or more cylindrical permanent magnets may be arranged between each cylindrical permanent magnet. .

Embodiment 11 FIG.
In the eleventh embodiment, as shown in FIG. 17, a cylindrical member (can) 30 such as SUS or FRP is prevented from scattering the magnet on the outermost periphery of a plurality of cylindrical permanent magnets 29a and 29b arranged in the radial direction. The cylindrical magnet (permanent magnet) 29 of the mover 22 is provided.
As a result, it is possible to prevent the cylindrical permanent magnets 29a and 29b from being scattered due to cracks and chips, which is useful for the maintenance of the cylindrical linear motor.

Embodiment 12 FIG.
In this embodiment, the cylindrical magnet of the mover 22 according to the above seventh to eleventh embodiments is applied to a slotless linear motor.
Cylindrical linear motors that do not use magnetic material near the air gap, such as slotless linear motors, have essentially small thrust pulsation (cogging force) when no current is applied and thrust pulsation (thrust ripple) when current is applied. It is often used in applications that require motors with small speed fluctuations, such as equipment. Conventionally, in such a linear motor, generally, the ratio of the length of the gap (distance between the mover 22 and the coil yoke) to the radial thickness of the cylindrical magnet is large. Was low.
In this embodiment, since the cylindrical magnet having a large radial thickness is applied to the slotless linear motor, the operating point can be effectively improved, and the gap magnetic flux density is effectively improved. By improving the magnetic flux density, less coil current is required for the stator 21 to generate thrust, copper loss is reduced, and efficiency is improved.

  In the above embodiment, the present invention is applied to the slotless linear motor. However, even if a coreless linear motor is used, the magnetic flux density can be effectively improved and the efficiency can be improved.

1 is a cross-sectional view of a permanent magnet motor according to Embodiment 1 of the present invention. It is sectional drawing which shows the rotor by Embodiment 1 of this invention. It is sectional drawing which shows the rotor as a comparative example of Embodiment 1 of this invention. It is sectional drawing which shows the rotor by Embodiment 2 of this invention. It is sectional drawing which shows the rotor by Embodiment 3 of this invention. It is sectional drawing which shows the rotor by Embodiment 4 of this invention. It is sectional drawing which shows the rotor by Embodiment 5 of this invention. It is sectional drawing of the permanent magnet type motor by Embodiment 6 of this invention. It is sectional drawing which shows the cylindrical linear motor by Embodiment 7 of this invention. It is sectional drawing which shows the needle | mover by Embodiment 7 of this invention. It is sectional drawing which shows the needle | mover by Embodiment 7 of this invention. It is sectional drawing which shows the needle | mover by Embodiment 8 of this invention. It is a figure explaining the magnetic flux of the needle | mover by Embodiment 8 of this invention. It is a figure explaining the magnetic flux of the needle | mover by another example of Embodiment 8 of this invention. It is sectional drawing which shows the needle | mover by Embodiment 9 of this invention. It is sectional drawing which shows the needle | mover by Embodiment 10 of this invention. It is sectional drawing which shows the needle | mover by Embodiment 11 of this invention.

Explanation of symbols

1 stator, 1b yoke (stator core), 2 rotor, 5 rotor core,
6 cylindrical magnet (permanent magnet), 6a first cylindrical permanent magnet,
6b 2nd cylindrical permanent magnet, 6c 3rd cylindrical permanent magnet,
11 cylindrical magnet (permanent magnet), 11a first cylindrical permanent magnet,
11b 2nd cylindrical permanent magnet, 11c 3rd cylindrical permanent magnet,
12 cylindrical magnet (permanent magnet), 12a, 12b cylindrical permanent magnet,
13 Iron member as a ferromagnetic material, 14 Cylindrical magnet (permanent magnet),
14a, 14b Cylindrical permanent magnet, 15 ring, 21 stator, 22 mover,
24 axis, 25 mover core, 26 cylindrical magnet (permanent magnet), 26A N-type cylindrical magnet,
26B S-type cylindrical magnet, 26a first N-type cylindrical permanent magnet,
26b second N-type cylindrical permanent magnet, 26c third N-type cylindrical permanent magnet,
26d first S-shaped cylindrical permanent magnet, 26e second S-shaped cylindrical permanent magnet,
26f 3rd S type cylindrical permanent magnet, 27A N type cylindrical magnet, 27B S type cylindrical magnet,
27a first N-type cylindrical permanent magnet, 27b second N-type cylindrical permanent magnet,
27c Third N-type cylindrical permanent magnet, 28 cylindrical magnet (permanent magnet),
28a, 28b Cylindrical permanent magnet, 29 Iron member as ferromagnetic material,
29 Cylindrical magnet (permanent magnet), 29a, 29b Cylindrical permanent magnet, 30 Cylindrical member.

Claims (15)

In a permanent magnet type rotating electrical machine including a rotor having a permanent magnet disposed on the outer periphery of a rotor core and a stator,
The permanent magnet of the rotor is formed by combining a plurality of cylindrical permanent magnets in a radial direction so that the inner peripheral surface of the outer cylindrical permanent magnet and the outer peripheral surface of the inner cylindrical permanent magnet are in close contact with each other.
Each of the cylindrical permanent magnets is magnetized with an equal number of magnetic poles in a radial or circumferential anisotropy, and the inner / outer diameter ratio is 0.75 to 0.95 in the case of radial anisotropy. In the case of directional anisotropy, the permanent magnet type rotating electrical machine is 0.6 to 0.8 . The permanent magnet type rotating electric machine according to claim 1, wherein the plurality of cylindrical permanent magnets constituting the permanent magnet include a cylindrical permanent magnet magnetized in a circumferential direction. The permanent magnet type rotating electrical machine according to claim 2, wherein the innermost cylindrical permanent magnet of the plurality of cylindrical permanent magnets constituting the permanent magnet is magnetized in the circumferential direction. 4. The permanent magnet type rotating electrical machine according to claim 2, wherein the outermost cylindrical permanent magnet of the plurality of cylindrical permanent magnets constituting the permanent magnet is magnetized in a radial direction. A non-magnetized ferromagnetic material is disposed between the cylindrical permanent magnets of the plurality of cylindrical permanent magnets, and the inner peripheral surface of the outer cylindrical permanent magnet and the outer peripheral surface of the inner cylindrical permanent magnet are The permanent magnet type rotating electrical machine according to any one of claims 1 to 4, wherein the permanent magnet type rotating electrical machine is in close contact via a magnetic body. The permanent magnet type rotating electrical machine according to any one of claims 1 to 5, wherein a ring for preventing magnet scattering is provided on the outermost periphery of the plurality of cylindrical permanent magnets constituting the permanent magnet. The permanent magnet type rotating electrical machine according to any one of claims 1 to 6, wherein the stator is a slotless type or a coreless type. In a cylindrical linear motor including a mover having permanent magnets arranged on the outer periphery of a mover core so that N poles and S poles are alternately arranged in the axial direction, and a stator,
A plurality of cylindrical permanent magnets each having a predetermined inner / outer diameter ratio and magnetized in a predetermined direction so that the inner peripheral surface of the outer cylindrical permanent magnet and the outer peripheral surface of the inner cylindrical permanent magnet are in close contact with each other. Combining in the radial direction to constitute the permanent magnet of the mover ,
The cylindrical linear motor, wherein the plurality of cylindrical permanent magnets include cylindrical permanent magnets magnetized in an axial direction . The plurality of the cylindrical permanent magnet constituting the permanent magnets, relatively cylindrical permanent magnet located outside are magnetized in the radial direction, relatively wear cylindrical permanent magnet located inside the axially magnetized 9. The cylindrical linear motor according to claim 8, wherein the cylindrical linear motor is formed. The cylindrical linear motor according to claim 9, wherein the outermost cylindrical permanent magnet of the plurality of cylindrical permanent magnets constituting the permanent magnet is magnetized in a radial direction. 11. The cylindrical linear motor according to claim 9, wherein the innermost cylindrical permanent magnet of the plurality of cylindrical permanent magnets constituting the permanent magnet is magnetized in the axial direction. The permanent magnet is configured by alternately arranging N-type permanent magnets and S-type permanent magnets, each of which is a combination of a plurality of cylindrical permanent magnets in the radial direction, and each N-type permanent magnet and each S-type magnet. The cylindrical linear motor according to claim 11, wherein the permanent magnet is arranged such that an axial position of the innermost cylindrical permanent magnet is shifted with respect to the other outer cylindrical permanent magnet. A non-magnetized ferromagnetic material is disposed between the cylindrical permanent magnets of the plurality of cylindrical permanent magnets, and the inner peripheral surface of the outer cylindrical permanent magnet and the outer peripheral surface of the inner cylindrical permanent magnet are The cylindrical linear motor according to any one of claims 8 to 12, wherein the cylindrical linear motor is closely attached via a magnetic body. The cylindrical linear motor according to any one of claims 8 to 13, wherein a cylindrical magnet scattering prevention member is provided on the outermost periphery of the plurality of cylindrical permanent magnets constituting the permanent magnet. The cylindrical linear motor according to any one of claims 8 to 14, wherein the stator is a slotless type or a coreless type.

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