JP2000197292A - Permanent-magnet rotor of permanent-magnet mounted motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To see that the rotor can lessen the cogging torque, lessen the vibration and noise, and further lessen the unevenness of rotation without incurring the cost up. SOLUTION: This rotor is provided with rectangular magnet mounting holes 22 at equal intervals by the number of poles of a rotor in the circumferential direction of a rotor iron core 21, and a permanent magnet 23 is mounted in each of the magnet mounting hole 22 so that the adjacent magnetic poles may vary from each other, with their magnetic pole facing in the radial direction of the iron core. In this case, the peripheral shape of the iron core magnetic pole 24 made at each peripheral magnetic pole face of the permanent magnet 23 is made in such circular form in every iron core magnetic pole that the distance from the center of the iron core becomes the largest at the center Pa in circumferential direction, and that the distance from the center of the iron core may be the smallest at the point Pb between poles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a brushless DC
The present invention relates to a rotor used in a permanent magnet type electric motor such as a motor, and more particularly to a permanent magnet type rotor having a plurality of permanent magnets for magnetic poles inside a rotor core.

[0002]

2. Description of the Related Art Conventionally, as this kind of permanent magnet type rotor, for example, one disclosed in Japanese Patent Application Laid-Open No. Hei 6-323292 (see FIG. 25A) and Japanese Patent Application Laid-Open No. 9-2243.
No. 38 (see FIG. 25 (b)).

The permanent magnet type rotor shown in FIGS. 25 (a) and 25 (b) is an example of a four-pole rotor, and includes a rotor core 100 and a circumferential direction of the rotor core 100. And permanent magnets 102 fitted and mounted in four rectangular magnet mounting holes 101 provided at equal intervals for the number of poles.

In the permanent magnet type rotor shown in FIG. 25A, the outer peripheral edge (bridge portion 103) of the rotor core 100 is provided between the permanent magnets 102 adjacent to each other in the circumferential direction of the rotor core 100. An opening 104 for preventing short circuit is provided, and the rotor core 100 has a circular shape. This permanent magnet type rotor is composed of each permanent magnet 102 and the rotor core 10.
An iron core pole portion 105 is formed in a region between the outer periphery of the core 0 and the outer periphery of the core.

In this permanent magnet type rotor, the rotor core 1
Since 00 is circular, the gap size between the stator and the rotor rotatably disposed inside the stator is substantially uniform over the entire circumference of the rotor.

In the permanent magnet type rotor shown in FIG. 25B, the rotor core 100 is
Are omitted in the salient pole shape. In this permanent magnet type rotor, the gap size between the stator and the rotor changes abruptly in a portion where the bridge portion 103 is not provided.

FIG. 26 shows another conventional example of a permanent magnet type rotor. In this permanent magnet type rotor, a permanent magnet 201 having an arc-shaped cross section is used.
In the circumferential direction, the permanent magnets 201 for the number of poles are incorporated so that the respective convex portions face the center of the rotor core 200.

In this permanent magnet type rotor, the rotor core 2
00 with the stator core 20 opposed thereto.
3 is configured such that the dimension of the gap 205 between the inner peripheral surface 204 and each magnetic pole increases from a portion corresponding to the circumferential center of the magnetic pole toward a portion corresponding to the space between the magnetic poles.

[0009]

FIG. 25 (a) and FIG. 25 (b)
In the conventional permanent magnet type rotor shown in FIG. 1, the magnetic flux density distribution of the air gap for each iron core magnetic pole portion 105 is trapezoidal, semi-elliptical or similar to the shape of the iron core magnetic pole portion 105. Therefore, the cogging torque during the rotation operation is large. For this reason, vibration and noise during the rotation operation increase, and in order to avoid these, there is a problem that measures such as skewing the stator core must be taken.

In the conventional permanent magnet type rotor as shown in FIG. 26, the magnetic flux of the arc-shaped permanent magnet 201 has a semi-elliptical shape or a shape close to the semi-elliptical shape on the inner diameter side of each arc. However, the cogging torque during the rotation operation cannot be sufficiently reduced even if the angle is changed, and the use of the arc-shaped permanent magnet 201 causes an increase in cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a permanent magnet type electric motor capable of reducing cogging torque, vibration and noise, and rotation unevenness without increasing cost. It is intended to obtain a permanent magnet type rotor.

[0012]

In order to achieve the above-mentioned object, a permanent magnet type rotor of a permanent magnet type electric motor according to the present invention is provided at equal intervals in the circumferential direction of a rotor core by the number of poles of the rotor. It has a rectangular magnet mounting hole penetrating in the axial direction with the iron core circumferential direction as the long side and the iron core radial direction as the short side, and each of the magnet mounting holes has a different magnetic pole adjacent to each other with the magnetic pole surface as the iron core radial direction. The permanent magnet is mounted as described above, and the outer peripheral shape of the core magnetic pole portion formed on each outer peripheral magnetic pole surface of the permanent magnet has the largest distance from the center of the iron core at the center in the circumferential direction, and at the gap between the poles Each core magnetic pole portion is formed in an arc shape such that the distance from the center of the iron core is minimized.

The permanent magnet type rotor of the permanent magnet type electric motor according to the present invention has a radial distance between the center of the iron core and a circumferential center of the iron core magnetic pole portion, and a radius Rb of an outer circumferential arc of the iron core magnetic pole portion. The radial distance between the center of the iron core and the gap between the poles is Rp
When Ra> Rb, 0.5 mm <(Ra−R
p) <5 mm.

The permanent magnet type rotor of the permanent magnet type electric motor according to the present invention is characterized in that the radial distance between the center of the iron core and the circumferential center of the iron core magnetic pole portion is Ra, and the radius of the outer circumferential arc of the iron core magnetic pole portion is Rb. When the number of poles of the rotor is eight,
{(0.8 · Ra) / 2} <Rb <｛(1.8 · Ra)
/ 2}.

The permanent magnet rotor of the permanent magnet type electric motor according to the next invention further has a minimum dimension La between the adjacent permanent magnets, an outer peripheral magnetic pole surface of the permanent magnet and an outer peripheral surface of the iron core magnetic pole portion. When Lb is the minimum dimension of
0.3 mm <La <3.0 mm, and 0.3 mm <Lb <
It is formed so as to have a relationship of 5.0 mm.

In the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the adjacent poles of the outer periphery of the magnetic pole portion of the iron core are connected by an arc of a small radius.

The permanent magnet type rotor of the permanent magnet type electric motor according to the next invention further has a shape in which the poles on the outer periphery of the adjacent magnetic core pole portion are connected by an arc having a radius Rc,
When the corners on both ends on the outer peripheral side of the magnet mounting hole are rounded with a radius Rd, and the radial dimension of the magnet mounting hole is Lc, the relationship of Rc <(Rb / 2) and Rd <Lc is satisfied. It is formed in.

In the permanent magnet type rotor for a permanent magnet type electric motor according to the next invention, both corners on the outer peripheral side of the magnet mounting hole are rounded with a radius Rd, and the radial dimension of the magnet mounting hole is Lc. In this case, Rd <Lc.

The permanent magnet type rotor of the permanent magnet type electric motor according to the next invention is further characterized in that an opening for preventing a magnetic flux short circuit is formed between the adjacent magnet mounting holes in an axial direction. is there.

The permanent magnet type rotor of the permanent magnet type electric motor according to the next invention further comprises a minimum dimension Ld between the magnetic flux short circuit preventing opening and the magnet mounting hole, and a magnetic flux short circuit preventing opening. Assuming that the minimum dimension between the iron core gap and the outer peripheral surface is Le, Ld and Le are substantially equal, and 0.3
The opening for preventing the magnetic flux short-circuit is formed so as to satisfy a relation of mm <(Ld and Le) <3 mm.

In the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the rotor iron core is constituted by a laminated body of steel plates having the same shape, and the gap between the outer circumferences of the iron core magnetic poles is formed in the axial direction by laser welding or the like. Is integrated by being welded.

In the permanent magnet type rotor for a permanent magnet type electric motor according to the next invention, a through-hole penetrating in the axial direction is further formed in the rotor core in an area inside the portion where the permanent magnets are arranged, and the through-hole is formed. Rotation balance of the rotor is performed by a weight reduction method as a lower conical hole.

In the permanent magnet type rotor for a permanent magnet type electric motor according to the next invention, a through-hole is formed in the rotor core in an area inside the portion where the permanent magnets are disposed, and the through-hole is formed in the axial direction. The rotation of the rotor is balanced by an increasing method of filling with a filler.

In the permanent magnet type rotor for a permanent magnet type electric motor according to the next invention, the circumferential length of the magnet mounting hole is larger than the circumferential length of the permanent magnet. It has a means for fixing at substantially the center in the circumferential direction.

In the permanent magnet rotor of the permanent magnet motor according to the next invention, after the permanent magnet is fitted into the magnet mounting hole, an epoxy adhesive or the like is injected into the gap of the magnet mounting hole. The permanent magnet is fixed.

The permanent magnet type rotor of the permanent magnet type electric motor according to the next invention has at least one magnet along the magnet mounting hole.
The permanent magnet is fixed to the magnet mounting hole after the permanent magnet is fitted into the magnet mounting hole, and an epoxy adhesive or the like is injected into the concave portion to fix the permanent magnet. It is.

In the permanent magnet type rotor of the permanent magnet type electric motor according to the present invention, the permanent magnet is further magnetized in a state where the permanent magnet is mounted in the magnet mounting hole.

In a permanent magnet rotor of a permanent magnet motor according to the next invention, the permanent magnet is a neodymium rare earth magnet.

A permanent magnet type rotor of a permanent magnet type electric motor according to the next invention uses a plurality of the permanent magnet type rotors according to the above-mentioned invention as a unit, and a predetermined number of the units are connected in the axial direction to be integrated. Is what is being done.

In the permanent magnet rotor of the permanent magnet motor according to the next invention, a predetermined number of the units are connected in the axial direction by being shifted by a predetermined angle in the radial direction, and are integrated.

A permanent magnet type rotor according to the next invention further comprises a plurality of slot openings on the inner peripheral surface and is rotatably disposed inside a stator core provided with concentrated windings. It is.

[0032]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a permanent magnet type rotor according to the present invention.

Embodiment 1 1 to 3 show a first embodiment of a permanent magnet type rotor and a permanent magnet type electric motor according to the present invention. The permanent magnet type electric motor is
, A permanent magnet rotor 20, a rotor shaft 40 that supports the permanent magnet rotor 20, a bearing member 41, and an outer structure 42.

The stator 10 is formed by stamping and stacking a silicon steel sheet into a predetermined shape, for example, a shape having twelve slot openings 11 in the inner peripheral surface as shown in FIG. Are provided with a three-phase winding 13 and are connected to a power supply unit by a lead wire 14. The number and the number of poles of the slot openings 11 of the stator core 12 are appropriately determined in consideration of characteristics.

The permanent magnet type rotor 20 has a rotor core 21 made of a laminate of silicon steel sheets punched into a predetermined shape.
And the magnet mounting holes 2 formed in the rotor core 21 for the number of poles.
2 and permanent magnets 23 for the number of poles fitted and mounted.

FIG. 3 shows a permanent magnet type rotor 2 having eight poles.
0 is shown. The rotor core 21 includes eight core magnetic poles 2
4, a rectangular shape penetrating in the axial direction with the long side being the circumferential direction and the short side being the radial direction provided at equal intervals in the circumferential direction of the rotor core 21 for eight rotor poles. The magnet mounting holes 22 are formed, and permanent magnets 23 are mounted in the respective magnet mounting holes 22 such that the pole faces are radial and the adjacent poles are different.

The permanent magnet 23 is magnetized while being mounted in the magnet mounting hole 22 provided in the core magnetic pole part 24. For this reason, the permeance at the time of magnetization increases, magnetization becomes easy, and the number of effective magnetic fluxes can be increased. Further, since the permanent magnet 23 can be mounted in the magnet mounting hole 22 without being magnetized, the permanent magnet 23 can be mounted without being affected by the magnetic attractive force, which can contribute to an improvement in productivity.

The permanent magnet 23 is made of a neodymium-based rare earth magnet, and has a size that can be securely mounted in the magnet mounting hole 22. Neodymium rare earth magnets are
Both the residual magnetic flux and the coercive force are large, and the magnetic energy product is extremely large. For this reason, the required number of gap magnetic fluxes can be secured even if the magnet area is reduced, and a required output can be obtained.

The outer peripheral shape of the core magnetic pole portion 24 formed on the outer peripheral magnetic pole surface of the permanent magnet 23 is such that the outer peripheral shape of the core magnetic pole portion 24 in the circumferential direction center (point) Pa from the center Ca of the rotor iron core 21 in the radial direction Each core magnetic pole portion 24 has an arc shape such that the distance is the largest and the radial distance from the core center Ca is the smallest at the outer peripheral pole portion (point) Pb of the core magnetic pole portion 24. In other words, the rotor core 21 has the shape of a chrysanthemum with the same number of poles as the number of poles.

The radial distance between the iron core center Ca and the circumferential center Pa of the iron core magnetic pole part 24 is Ra, the center of the outer circumferential arc of the iron core magnetic pole part 24 is Cb, and the outer circumferential radius of the iron core magnetic pole part 24 is Rb. When the number of poles of the rotor is eight, these values may be appropriately determined within a range that is characteristically and structurally acceptable. As can be seen from the graph shown in FIG.
The core center Ca, the center Pa in the circumferential direction of the core magnetic pole part 24, and the center Cb of the outer circumferential arc of the core magnetic pole part 24 are the respective core magnetic pole parts 2.
4 are on the same line and {(0.8 · Ra) / 2} <R
It is preferable that b <{(1.8 · Ra) / 2}.

According to the above-described configuration, the gap distance between the stator 10 and the permanent magnet type rotor 20 is different for each core magnetic pole portion 24 of the permanent magnet type rotor 20. The resistance gradually increases from the center Pa in the circumferential direction to the gap Pb, and the magnetic resistance of the corresponding portion also increases in proportion thereto.

For this reason, the magnetic flux density distribution of the air gap for each iron core magnetic pole portion 24 is small at the portion corresponding to the gap Pb, concentrated at the portion corresponding to the circumferential central portion Pa,
It becomes a distribution close to a Gaussian distribution or a sine wave. As a result, cogging torque is suppressed, and vibration and noise during the rotation operation are reduced as compared with the conventional one.

FIG. 5A shows a waveform of a cogging torque generated in this embodiment, and FIG. 5B shows a typical waveform of a cogging torque generated in the conventional device. As is clear from FIGS. 5A and 5B, it is understood that the cogging torque of this embodiment can be greatly reduced as compared with the conventional one.

If the value of the outer circumferential arc Rb of the core magnetic pole portion 24 is too small, the induced voltage may decrease and a sufficient motor output may not be obtained. If the value is too large, the effect of reducing cogging torque cannot be obtained, and vibration and noise are generated.

When the minimum dimension between the adjacent permanent magnets 23 is La and the minimum dimension between the outer peripheral magnetic pole surface of the permanent magnet 23 and the outer peripheral surface of the iron core magnetic pole portion 24 is Lb, these values are particularly important. Is not limited, but 0.3 mm <La <
It is preferable that they are formed so as to be 3.0 mm and 0.3 mm <Lb <5.0 mm.

If the values of La and Lb are too small, the rotor 2
If the rotational strength of 0 is insufficient and the values of La and Lb are too large, the effect of suppressing the leakage magnetic flux of the permanent magnet 23 decreases,
As a result, the induced voltage decreases, and a sufficient motor output cannot be obtained.

In the above embodiment, as shown in FIG. 2, twelve slot openings 11 are formed on the inner peripheral surface.
The present invention is applied to the permanent magnet rotor 20 having eight magnetic poles disposed inside the stator core 12 provided with the concentrated winding, but the permanent magnet rotor according to the present invention is provided. The present invention is not limited to this, and is also effective for a permanent magnet type rotor having a distributed winding.

Embodiment 2 FIG. 6 shows a second embodiment of the permanent magnet type rotor according to the present invention. In FIG. 6, portions corresponding to those in FIG. 3 are denoted by the same reference numerals as those in FIG. 3, and description thereof will be omitted.

In the second embodiment, in addition to the structure of the first embodiment, the inter-pole portion 25 on the outer periphery of the adjacent core magnetic pole portion is provided.
Are connected by a small radius arc formed by the radius Rc. Further, both outer corners 26 of the magnet mounting hole 22 are formed in a round shape with a radius Rd. The value of the radius Rc of the connecting arc of the inter-pole portion 25 is not particularly limited, and is determined as appropriate depending on the outer dimensions of the rotor 22, the outer peripheral surface arc diameter Rb of the core magnetic pole portion 24, and the like. If it is too large, the cogging torque reduction effect decreases, so that it is preferable to set Rc <(Rb / 2).

The outer peripheral corners 2 of the magnet mounting hole 22
The radius Rd of No. 6 is such that the relationship Rd <Lc is satisfied when the radial length of the magnet mounting hole 22 is Lc in order to suppress the leakage magnetic flux of the permanent magnet 23 while securing the rotational strength. Preferably, it is formed.

Embodiment 3 FIG. 7 and 8 show a third embodiment of the permanent magnet type rotor according to the present invention. In FIGS. 7 and 8, portions corresponding to FIGS. 2 and 3 are denoted by the same reference numerals as those in FIGS. 2 and 3, and the description thereof is omitted.

This embodiment shows a permanent magnet type rotor 20 having four poles. The rotor core 21 has four core magnetic pole portions 24, and the circumferential direction provided at equal intervals by the number of poles of the rotor in the circumferential direction of the rotor core 21 is set to be a long side and a radial direction is short. Four rectangular magnet mounting holes 22 penetrating in the axial direction as sides are formed, and permanent magnets 23 are mounted in each of the magnet mounting holes 22 such that the magnetic pole surface is in the radial direction and adjacent poles are different. .

Also in this embodiment, the permanent magnet 23 is magnetized in a state where it is mounted in the magnet mounting hole 22 provided in the iron core magnetic pole part 24. For this reason, the permeance at the time of magnetization increases, magnetization becomes easy, and the number of effective magnetic fluxes can be increased. Further, since the permanent magnet 23 can be mounted in the magnet mounting hole 22 without being magnetized, the permanent magnet 23 can be mounted without being affected by the magnetic attractive force, which can contribute to an improvement in productivity.

The outer peripheral shape of the core magnetic pole portion 24 formed on the outer peripheral magnetic pole surface of the permanent magnet 23 is such that the outer peripheral shape of the core magnetic pole portion 24 at the circumferential central portion (point) Pa from the center Ca of the rotor iron core 21 in the radial direction Each core magnetic pole portion 24 has an arc shape such that the distance is the largest and the radial distance from the core center Ca is the smallest at the outer peripheral pole portion (point) Pb of the core magnetic pole portion 24. In other words, the rotor core 21 has a flower shape with the same number of poles as the number of poles.

Also in this case, the iron core center Ca and the iron core
4, the radial distance from the circumferential central portion Pa is Ra, the center of the outer circumferential arc of the core magnetic pole portion 24 is Cb, the radius of the outer circumferential arc of the core magnetic pole portion 24 is Rb, and the diameter between the iron core center Ca and the pole portion Pb. When the directional distance is Rp, these values may be determined as appropriate within a range that is characteristically and structurally acceptable, but as shown in FIG. 9, the value of (Ra−Rp) is too large. When the value of (Ra-Rp) is too small, the effect of reducing the cogging torque cannot be obtained, and vibration and noise are generated. The center Ca of the core, the center Pa in the circumferential direction of the core magnetic pole part 24, and the center Cb of the outer peripheral arc of the core magnetic pole part 24 are on the same line for each core magnetic pole part 24, and Ra> Rb and 0.5 mm <( Ra−Rp) <5 mm Masui.

In the above-described configuration, the air gap distance between the stator 10 and the permanent magnet type rotor 20 is different for each core magnetic pole portion 24 of the permanent magnet type rotor 20 in the circumferential direction of the core magnetic pole portion 24. The resistance gradually increases from the center Pa toward the gap Pb, and the magnetic resistance of the corresponding portion also increases in proportion thereto.

For this reason, the magnetic flux density distribution of the air gap for each iron core magnetic pole portion 24 is small at the portion corresponding to the gap portion Pb, and concentrated at the portion corresponding to the circumferential central portion Pa.
It becomes a distribution close to a Gaussian distribution or a sine wave. Thereby, the cogging torque is suppressed, and vibration and noise during the rotation operation are reduced as compared with the conventional one.

Also in this embodiment, the minimum dimension between the permanent magnets 23 (magnet mounting holes 22) adjacent to each other is L.
a, when the minimum dimension between the magnet mounting hole 22 and the outer peripheral surface of the iron core magnetic pole part 24 is Lb, these values are not particularly limited, but 0.3 mm <La <3.0 mm and 0.3 mm <L
It is preferable that b <5.0 mm be satisfied. If the values of La and Lb are too small, the rotor 2
In contrast, if the rotational strength of La is not sufficient and the values of La and Lb are too large, the effect of suppressing the leakage magnetic flux of the permanent magnet 23 is reduced, and as a result, the induced voltage is reduced and a sufficient motor No output can be obtained.

The rotor core 21 is formed of a laminated body of silicon steel plates having the same shape, and the outer peripheral portion Pb of the core magnetic pole portion 24 is axially welded by laser welding or the like to be integrated (blocked). ing. The rotor core 21 of the permanent magnet type rotor 20 is usually formed by fixing a silicon steel plate punched into a predetermined shape by caulking or the like.
The peripheral pole portion Pb of the core magnetic pole portion 24 is axially welded by laser welding or the like, and the laminated silicon steel sheets are fixed to each other, so that sufficient rotational strength can be ensured even at high speed rotation. it can.

It should be noted that the rotor core 21 having sufficient rotational strength for high-speed rotation can be formed easily and inexpensively by laser welding alone without using caulking and laser welding together. Further, in the case of a four-pole rotor, whether to weld all of the four peripheral inter-pole portions Pb or to make two portions is determined as follows.
It can be selected according to predetermined characteristics.

Embodiment 4 FIG. 10 shows a fourth embodiment of the permanent magnet type rotor according to the present invention. In the fourth embodiment, in addition to the configuration of the above-described third embodiment, an opening 50 for preventing a magnetic flux short circuit is formed between the adjacent magnet mounting holes 22 in the axial direction.

An opening 50 for preventing a magnetic flux short circuit and a magnet mounting hole 2
Ld is the minimum dimension between the two and the opening 50 for preventing magnetic flux short circuit.
When the minimum dimension between the core and the outer peripheral surface of the core gap portion 24 is Le, these values are not particularly limited, but Ld and Le
Are approximately equal, and 0.3 mm <(Ld and Le) <3 m
Preferably, they are formed so as to have a relationship of m.

The magnetic flux leakage of the permanent magnet 23 can be effectively suppressed by the opening 50 for preventing the magnetic flux short circuit.
If the values of Ld and Le are too small, the rotational strength of the rotor 20 will be insufficient. Conversely, if the values of Ld and Le are too large, the effect of suppressing the leakage magnetic flux of the permanent magnet 23 will decrease, As a result, the induced voltage decreases, and a sufficient motor output cannot be obtained.

The formation of the opening 50 for preventing magnetic flux short-circuit can be similarly applied to the eight-pole rotor shown in the first and second embodiments.

Embodiment 5 FIG. 11 shows a fifth embodiment of the permanent magnet type rotor according to the present invention. In the fifth embodiment, in addition to the configuration of the above-described fourth embodiment, both end corners 26 on the outer peripheral side of the magnet mounting hole 22 are formed in a round shape with a radius Rd.

The radius Rd of the corners 26 at both ends on the outer peripheral side of the magnet mounting hole 22 is set so that the permanent magnet 23
In order to suppress the leakage magnetic flux, when the length of the magnet mounting hole 22 in the radial direction is Lc, it is preferable that the magnet mounting hole 22 be formed so as to satisfy the relationship of Rd <Lc.

Embodiment 6 FIG. 12 and 13 show a sixth embodiment of the permanent magnet rotor according to the present invention. In this embodiment, in addition to the configuration of the above-described first or second embodiment, a small-diameter through-hole
7 is formed for each permanent magnet 23.

By using the through hole 27 as a lower conical hole and performing a conical hole processing 28 at the end, the rotation of the permanent magnet type rotor 20 can be balanced by the weight reduction method.
The positions and diameters of the conical holes are selected so as to minimize the influence on the characteristics of the permanent magnet 23, and rotation balancing is performed by using a plurality of through holes 27 at both axial end surfaces of the permanent magnet type rotor 20.
Can be performed. The through-hole 27 can be punched out simultaneously when the rotor core 21 is punched into a predetermined shape, and can be easily formed at low cost. The rotation balancing of the permanent magnet type rotor 20 by performing the drilling 28 on the through hole 27 as described above can be similarly applied to a four-pole rotor as shown in FIG.

Embodiment 7 15 and 16 show a seventh embodiment of the permanent magnet rotor according to the present invention. In this embodiment, in addition to the structure of the above-described first or second embodiment, a relatively large diameter, for example, a diameter of 5 to 2
A through hole 29 of about 0 mm is formed for each permanent magnet 23.

By filling the through-hole 29 with the filler 30 such as an adhesive putty, the rotation of the permanent magnet type rotor 20 can be balanced by an increasing method. The positions and diameters of the through holes 29 are selected so as to minimize the influence on the characteristics of the permanent magnet 23. Rotation balancing is performed by using a plurality of through holes 29 at both axial end surfaces of the permanent magnet type rotor 20. Can be performed.

The through-hole 29 can also be punched out simultaneously when the rotor core 21 is punched into a predetermined shape, and can be easily formed at low cost.

The rotation balancing of the permanent magnet type rotor 20 by filling the through hole 29 with the filler 30 such as an adhesive putty is similarly applied to a four-pole rotor as shown in FIG. it can.

Embodiment 8 FIG. FIG. 18 shows an eighth embodiment of the permanent magnet type rotor according to the present invention. In this embodiment, in addition to the configuration of the above-described embodiment, the circumferential length of the magnet mounting hole 22 is larger than the circumferential length of the permanent magnet 23, and the permanent magnet 23 is moved in the circumferential direction of the magnet mounting hole 22. Has a protruding portion 31 as a means for fixing it substantially at the center. The permanent magnet 23 is fixed with both sides sandwiched between the projections 31 in the magnet mounting hole 22. Thereby, the leakage magnetic flux of the permanent magnet 23 is suppressed, and the permanent magnet 23 can be easily fixed and mounted.

The permanent magnet 23 is fixed to the rotor core 21 by injecting an epoxy adhesive or the like into a gap 51 formed on both sides of the magnet mounting hole 22 after the permanent magnet 23 is fitted into the magnet mounting hole 22. Can be reliably performed with an adhesive. Thereby, the permanent magnet 2 can be easily manufactured at low cost.
3 can be fixed to the rotor core 21.

Embodiment 9 FIG. FIG. 19 shows a ninth embodiment of the permanent magnet rotor according to the present invention. In this embodiment, in addition to the configuration of the above-described embodiment, the circumferential length of the magnet mounting hole 22 is larger than the circumferential length of the permanent magnet 23, and the permanent magnet 23 is moved in the circumferential direction of the magnet mounting hole 22. Has a step 32 as a means for fixing it to substantially the center of the. The permanent magnet 23 is fixed with both sides sandwiched between the step walls of the step part 32 in the magnet mounting hole 22. Accordingly, also in this embodiment, the leakage magnetic flux of the permanent magnet 23 is suppressed, and the permanent magnet 23 can be easily fixed and mounted. Thereby, the permanent magnet 23 can be easily fixed to the rotor core 21 at low cost.

Also in this case, the rotor core 2 of the permanent magnet 23
After the permanent magnet 23 is fitted into the magnet mounting hole 22, the gap 5 formed on both sides of the magnet mounting hole 22 is fixed to the magnet mounting hole 22.
By injecting an epoxy-based adhesive or the like into 1, it is possible to reliably perform the operation with the adhesive.

The fixing and fixing of the permanent magnet 23 as described above can be similarly applied to a four-pole rotor as shown in FIGS.

Embodiment 10 FIG. FIG. 22 shows a tenth embodiment of a permanent magnet type rotor according to the present invention. In this embodiment, a concave portion 52 is formed at least in one place along the magnet mounting hole 22, and is formed as a concave portion.
After the permanent magnet 23 is fitted into the magnet mounting hole 22, an epoxy-based adhesive or the like is injected into the concave portion 52, whereby the permanent magnet 23 is fixed to the rotor core 21. Therefore, also in this case, the permanent magnet 23 can be easily fixed to the rotor core 21 at low cost.

Embodiment 11 FIG. FIG. 23 shows an eleventh embodiment of the permanent magnet rotor according to the present invention. In this embodiment, a plurality (predetermined number) of the permanent magnet type rotors 20 having the above-described configuration are stacked and connected in the axial direction of a rotor shaft (omitted in the drawing) as a unit, and the whole is integrated into a whole. As one permanent magnet type rotor (the permanent magnet 23 is not shown). As described above, by performing the unitization, a permanent magnet type rotor of a large capacity machine can be manufactured by a combination of a small and standardized unit, which can contribute to improvement in productivity and cost reduction.

Embodiment 12 FIG. FIG. 24 shows a twelfth embodiment of the permanent magnet rotor according to the present invention. In the tenth embodiment, a plurality (predetermined number) of units of the permanent magnet type rotor 20 having the above-described configuration are provided.
The rotor shaft (omitted in the figure) is axially stacked and connected while being shifted at a predetermined angle in the radial direction of the rotor shaft, and is integrally formed as a whole as one permanent magnet type rotor (the permanent magnet 23 is shown in the figure). Omitted).

By mounting each unit on the rotor shaft while shifting it at a predetermined angle, the skew effect
The cogging torque can be further reduced, and vibration / noise and, consequently, rotation unevenness can be reduced.

In the eleventh and twelfth embodiments,
Although three units of the permanent magnet type rotor 20 are used,
The permanent magnet type rotor according to the present invention is not limited to this, and is also effective for the optimum number of units for obtaining predetermined characteristics. In the above-described embodiment, the case where the number of poles of the rotor is eight or four is described. However, the permanent magnet type rotor according to the present invention is effective for rotors having other numbers of poles. It is.

[0083]

As will be understood from the above description, according to the permanent magnet type rotor of the permanent magnet type electric motor according to the present invention, the magnetic flux density distribution of the air gap for each magnetic pole is Gaussian due to the shape effect of the core magnetic pole portion. A distribution or a distribution close to a sine wave is obtained. As a result, cogging torque can be reduced, and vibration, noise, and uneven rotation can be reduced.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the radial distance between the center of the iron core and the center in the circumferential direction of the magnetic pole of the iron core and the radial distance between the poles can be appropriately set. In addition, the magnetic flux density distribution of the air gap for each magnetic pole becomes a distribution close to a Gaussian distribution or a sine wave. As a result, cogging torque can be reduced, and vibration, noise, and uneven rotation can be reduced.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the radial distance between the center of the iron core and the center in the circumferential direction of the iron core magnetic pole portion, and the appropriate setting of the radius of the outer circumferential arc of the iron core magnetic pole portion. As a result, the magnetic flux density distribution of the air gap for each magnetic pole becomes a distribution close to a Gaussian distribution or a sine wave. As a result, cogging torque can be reduced, and vibration, noise, and uneven rotation can be reduced.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the minimum size between the permanent magnets adjacent to each other and the minimum size between the outer peripheral surface of the permanent magnet and the outer peripheral surface of the core magnetic pole portion. With the appropriate setting, it is possible to suppress the leakage magnetic flux while securing the rotational strength, and to improve the output of the motor.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the cogging torque can be further reduced because the inter-pole portions on the outer periphery of the adjacent core magnetic pole portions are connected by a small-radius arc. Effectively reduce.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the arc radius of the inter-pole portion of the outer periphery of the adjacent magnetic pole portion of the iron core is set appropriately, and the corners at both ends on the outer peripheral side of the magnet mounting hole are set. Are rounded, and the radius of the rounded shape is appropriately set, so that the cogging torque can be further effectively reduced and the rotational strength of the rotor can be secured.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the corners at both ends on the outer peripheral side of the magnet mounting hole are formed in a round shape, and the radius of the round shape is appropriately set. The magnetic flux can be further effectively reduced, and the rotational strength of the rotor can be secured.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, an opening for preventing a magnetic flux short circuit is provided between the permanent magnets adjacent to each other, thereby suppressing the leakage magnetic flux while securing the rotational strength. be able to.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the minimum dimension between the permanent magnet and the magnetic flux short-circuit preventing opening and the minimum distance between the magnetic flux short-circuit preventing opening and the outer peripheral surface of the iron core magnetic pole portion. By appropriately setting the dimensions, it is possible to suppress the leakage magnetic flux while securing the rotational strength, and to improve the output of the motor.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the pole portions of the outer periphery of the core magnetic pole portion of the rotor core are fixed in the axial direction by laser welding or the like, so that the lamination is performed. The silicon steel sheet can be further firmly fixed, and sufficient rotational strength can be obtained even at high speed rotation.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the through hole formed in the rotor core in the area inside the permanent magnet arrangement portion in the axial direction is defined as the lower conical hole by the weight reduction method. Thus, the rotation balance of the rotor can be performed, and the through-hole can be punched out at the same time as the rotor core is punched into a predetermined shape.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the filler is filled in the through-hole formed in the rotor core in the region inside the permanent magnet arrangement portion in the axial direction. The rotation balance of the rotor can be performed by the increasing method, and the through-hole can be punched at the same time when the rotor core is punched into a predetermined shape. Therefore, the balancing method can be performed at low cost by the increasing method.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the circumferential length of the magnet mounting hole is larger than the circumferential length of the permanent magnet, and the permanent magnet is substantially in the circumferential direction of the magnet mounting hole. Since the permanent magnet is fixed at the center, the leakage flux of the permanent magnet can be suppressed, and the permanent magnet can be easily fixed and mounted.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the permanent magnet is fixed by injecting the adhesive into the gap of the magnet mounting hole. High strength can be obtained.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, after the permanent magnet is fitted into the magnet mounting hole, the epoxy adhesive or the like is inserted into the concave portion formed on the inner peripheral surface of the magnet mounting hole. , The permanent magnet is fixed, so that sufficient strength can be obtained even at high speed rotation.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, the permanent magnet is magnetized while being mounted in the magnet mounting hole, so that the permeance at the time of magnetization increases, and the magnetization is increased. And the number of effective magnetic fluxes can be increased, and the permanent magnet can be mounted in the mounting hole without being magnetized, so it can be mounted without being affected by the magnetic attraction force, improving productivity. Can contribute.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, since the permanent magnet is a neodymium rare earth magnet, the necessary gap magnetic flux number can be secured even if the magnet area is reduced, and the required number of gap magnetic fluxes can be secured. Output can be obtained.

According to the permanent magnet type rotor of the permanent magnet type electric motor according to the next invention, since a plurality of unitized permanent magnet type rotors are laminated in the axial direction and integrated, the productivity is improved. Improvement and cost reduction can be performed.

According to the permanent magnet rotor of the permanent magnet electric motor according to the next invention, a plurality of unitized permanent magnet rotors are laminated in the axial direction while being shifted at a predetermined angle in the radial direction and integrated. The cogging torque can be further reduced by the skew effect,
Vibration, noise, and uneven rotation can be reduced.

According to the permanent magnet type rotor according to the next invention, a plurality of slot openings are provided on the inner peripheral surface, and the rotor is rotatably disposed inside the stator core on which the concentrated winding is provided. Combination with a stator having a concentrated winding makes it possible to reduce the size and weight.

[Brief description of the drawings]

FIG. 1 is an axial cross-sectional side view showing a first embodiment of a permanent magnet type electric motor incorporating a permanent magnet type rotor according to the present invention.

FIG. 2 is a cross-sectional view in a direction perpendicular to an axis showing the first embodiment of the permanent magnet type electric motor incorporating the permanent magnet type rotor according to the present invention.

FIG. 3 is a front view showing Embodiment 1 of the permanent magnet rotor of the permanent magnet electric motor according to the present invention.

FIG. 4: {(0.8 · Ra) / 2} <Rb <｛(1.
8 is a graph showing the basis of the relationship of 8 · Ra) / 2 ／.

5A is a graph showing a cogging torque of the permanent magnet type electric motor according to the first embodiment, and FIG. 5B is a graph showing a typical cogging torque of the conventional permanent magnet type electric motor.

FIG. 6 is a front view showing a second embodiment of the permanent magnet rotor of the permanent magnet electric motor according to the present invention;

FIG. 7 is a cross-sectional view in a direction perpendicular to an axis, showing a third embodiment of the permanent magnet rotor of the permanent magnet electric motor according to the present invention;

FIG. 8 is a front view showing Embodiment 3 of the permanent magnet rotor of the permanent magnet electric motor according to the present invention.

FIG. 9 is a graph showing the relationship between the radius of the outer peripheral arc of the core magnetic pole portion of the permanent magnet type rotor, the cogging torque, and the induced voltage in the permanent magnet type electric motor according to the third embodiment.

FIG. 10 is a front view showing a permanent magnet type rotor for a permanent magnet type electric motor according to a fourth embodiment of the present invention;

FIG. 11 is a front view showing Embodiment 5 of the permanent magnet rotor of the permanent magnet electric motor according to the present invention.

FIG. 12 is a front view showing a permanent magnet rotor according to a sixth embodiment of the present invention.

FIG. 13 is an axial sectional view showing a sixth embodiment of the permanent magnet rotor according to the present invention.

FIG. 14 is a front view showing another example of Embodiment 6 of the permanent magnet rotor according to the present invention.

FIG. 15 is a front view showing a permanent magnet rotor according to a seventh embodiment of the present invention.

FIG. 16 is an axial sectional view showing a seventh embodiment of the permanent magnet rotor according to the present invention.

FIG. 17 is a front view showing another example of the permanent magnet rotor according to the seventh embodiment of the present invention.

FIG. 18 is a partial front view showing a permanent magnet rotor according to an eighth embodiment of the present invention.

FIG. 19 is a partial front view showing a ninth embodiment of a permanent magnet rotor according to the present invention.

FIG. 20 is a front view showing another example of the ninth embodiment of the permanent magnet rotor according to the present invention.

FIG. 21 is a front view showing another example of the ninth embodiment of the permanent magnet rotor according to the present invention.

FIG. 22 is a partial front view showing a tenth embodiment of a permanent magnet rotor according to the present invention.

FIG. 23 is a perspective view showing a permanent magnet rotor according to an eleventh embodiment of the present invention.

FIG. 24 is a perspective view showing a twelfth embodiment of the permanent magnet type rotor according to the present invention.

FIGS. 25A and 25B are front views each showing the structure of a conventional permanent magnet rotor.

FIG. 26 is a front view showing another structural example of a conventional permanent magnet rotor.

[Explanation of symbols]

Reference Signs List 10 stator, 11 slot opening, 12 stator core, 13 three-phase winding, 14 lead wire, 20 permanent magnet type rotor, 21 rotor core, 22 magnet mounting hole, 23
Permanent magnet, 24 core magnetic pole part, 25 pole part, 26
Outer end corners, 27 through holes, 28 drilled holes, 2
9 through-hole, 30 filler, 31 protrusion, 32 step, 40 rotor shaft, 41 bearing member, 42 outer structure, 50 opening for preventing magnetic flux short-circuit, 51 gap, 52 recess.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H02K 21/14 H02K 21/14 MF term (Reference) 5H615 AA01 BB01 BB14 BB16 PP02 PP07 PP21 SS03 SS05 SS51 TT05 5H621 AA02 GA01 GA04 GA16 HH01 HH09 JK02 JK05 5H622 AA02 CA02 CA05 CA13 CA14 CB05 CB06 DD02 PP03 PP10 PP11 PP19 QB03

Claims (20)

[Claims] A rectangular magnet mounting hole is provided at equal intervals in the circumferential direction of the rotor core, the number being equal to the number of poles of the rotor, and penetrates in the axial direction with the long side in the circumferential direction of the core and the short side in the radial direction of the core. A permanent magnet is mounted on each of the magnet mounting holes such that magnetic pole surfaces adjacent to each other are different with the magnetic pole surface being the iron core radial direction,
The outer peripheral shape of the core magnetic pole portion formed on the outer peripheral magnetic pole surface of each of the permanent magnets is such that the distance from the center of the iron core is largest at the center in the circumferential direction, and the distance from the center of the iron core is the largest at the gap between the poles. A permanent magnet type rotor of a permanent magnet type electric motor characterized in that each core magnetic pole portion is formed in an arc shape so as to be small. 2. The radial distance between the center of the iron core and the circumferential center of the core magnetic pole portion is Ra, the radius of the outer circumferential arc of the core magnetic pole portion is Rb, and the radial distance between the center of the iron core and the inter-pole portion is Rp. When Ra> Rb, 0.5 mm <(Ra−Rp)
The permanent magnet type rotor of a permanent magnet type electric motor according to claim 1, wherein the rotor is formed so as to have a relation of <5 mm. 3. When the radial distance between the center of the iron core and the circumferential center of the iron core magnetic pole part is Ra, the radius of the outer circumferential arc of the iron core magnetic pole part is Rb, and the number of poles of the rotor is eight poles, (0.
The permanent magnet type electric motor according to claim 1, wherein the relationship is established as follows: (8 · Ra) / 2｝ <Rb <{(1.8 · Ra) / 2}. Rotor. 4. When the minimum dimension between the permanent magnets adjacent to each other is La, and the minimum dimension between the outer peripheral magnetic pole surface of the permanent magnet and the outer peripheral surface of the core magnetic pole portion is Lb, 0.3 mm
<La <3.0 mm, 0.3 mm <Lb <5.0 mm
The permanent magnet type rotor of a permanent magnet type electric motor according to any one of claims 1 to 3, wherein the rotor is formed so as to satisfy the following relationship. 5. The method according to claim 1, wherein the gaps between the outer circumferences of the adjacent core magnetic pole portions are connected by an arc having a small radius.
5. A permanent magnet type rotor for a permanent magnet type electric motor according to any one of items 1 to 4. 6. The magnet mounting portion according to claim 6, wherein the outer periphery of the adjacent core magnetic pole portion has a shape in which the poles are connected by an arc having a radius of Rc, and both outer corners of the magnet mounting hole have a radius shape having a radius of Rd. When the radial dimension of the hole is Lc, R
6. The permanent magnet type rotor according to claim 5, wherein c <(Rb / 2) and Rd <Lc. 7. An outer peripheral corner of the magnet mounting hole is formed in a round shape with a radius Rd, and when a radial dimension of the magnet mounting hole is Lc, a relationship of Rd <Lc is established. The permanent magnet type rotor of a permanent magnet type electric motor according to any one of claims 1 to 5, wherein 8. The method according to claim 1, wherein an opening for preventing a magnetic flux short circuit is formed between the adjacent magnet mounting holes so as to penetrate in the axial direction. Permanent magnet rotor of permanent magnet motor. 9. A minimum dimension between the magnetic flux short-circuit preventing opening and the magnet mounting hole is Ld, and a minimum dimension between the magnetic flux short-circuit preventing opening and the outer peripheral surface of the core gap is Le. , Ld and Le are almost equal, and 0.3 mm <(L
9. The permanent magnet type rotor of a permanent magnet type electric motor according to claim 8, wherein the opening for preventing the magnetic flux short circuit is formed such that d and Le) <3 mm. 10. The rotor core is formed of a laminated body of steel plates having the same shape, and is integrated by being welded in an axial direction by laser welding or the like at an outer peripheral portion of the magnetic pole portion of the iron core. The permanent magnet type rotor of the permanent magnet type electric motor according to any one of claims 1 to 9, characterized in that: 11. A through-hole penetrating in the axial direction is formed in a rotor core in an area inside the arrangement portion of the permanent magnet, and the rotation of the rotor is balanced by a weight reduction method using the through-hole as a lower conical hole. The permanent magnet type rotor of the permanent magnet type electric motor according to any one of claims 1 to 10, wherein 12. A through hole penetrating in the axial direction is formed in a rotor core in a region inside the permanent magnet arrangement portion, and rotation of the rotor is balanced by an increasing method of filling the through hole with a filler. The permanent magnet type rotor of a permanent magnet type electric motor according to any one of claims 1 to 10, wherein 13. The magnet mounting hole according to claim 1, wherein a circumferential length of the magnet mounting hole is larger than a circumferential length of the permanent magnet, and a means for fixing the permanent magnet substantially at a center of the magnet mounting hole in a circumferential direction is provided. A permanent magnet type rotor for a permanent magnet type electric motor according to claim 1. 14. After the permanent magnet is fitted into the magnet mounting hole, an epoxy-based adhesive or the like is injected into a gap of the magnet mounting hole to fix the permanent magnet. A permanent magnet type rotor for a permanent magnet type electric motor according to claim 13. 15. At least one along the magnet mounting hole
After the permanent magnet is fitted into the magnet mounting hole, an epoxy-based adhesive or the like is injected into the concave portion to fix the permanent magnet. The permanent magnet type rotor of a permanent magnet type electric motor according to any one of claims 1 to 12, wherein 16. The apparatus according to claim 1, wherein said permanent magnet is magnetized in a state of being mounted in said magnet mounting hole.
5. A permanent magnet type rotor of the permanent magnet type electric motor according to any one of the above items 5. 17. The permanent magnet rotor according to claim 1, wherein the permanent magnet is a neodymium rare earth magnet. 18. A plurality of permanent magnet type rotors according to claim 1 are used as a unit,
A permanent magnet type rotor of a permanent magnet type electric motor, wherein a predetermined number of the units are connected and integrated in the axial direction. 19. The permanent magnet type rotation of a permanent magnet type electric motor according to claim 18, wherein a predetermined number of said units are connected in the axial direction by being shifted by a predetermined angle in a radial direction. Child. 20. The method according to claim 1, wherein a plurality of slot openings are provided on the inner peripheral surface, and the plurality of slot openings are rotatably disposed inside the stator core on which the concentrated windings are provided. A permanent magnet rotor of the permanent magnet electric motor according to any one of the above.