JP2001178036A - Permanent-magnet dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent-magnet electric rotating machine, capable of reducing cogging torque and iron loss and obtaining sufficient main magnetic flux torque. SOLUTION: The magnetic poles of a permanent magnet 9 are so oriented that their focal points are positioned substantially on a d-axis connecting the axis of a rotor 6 and the center of the permanent magnet 9 in the circumferential direction and the focal point of the magnetic pole orientation becomes more distant, going from the both-side ends of the permanent magnet 9 in the circumferential direction, toward its center in the circumferential direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet type rotating electric machine having a rotor core having a plurality of permanent magnets.

[0002]

2. Description of the Related Art Generally, permanent magnet type rotating electric machines are widely used for electric products such as air conditioners. In this type of permanent magnet type rotating electric machine, various magnetic pole orientations are provided to the permanent magnet to reduce cogging torque of the rotating electric machine, reduce iron loss due to leakage magnetic flux, and improve characteristics.

[0003] For example, Japanese Patent Application Laid-Open No. 7-39090 discloses that the cogging torque is reduced by concentrating the magnetic pole orientation of the permanent magnet at one point outside the permanent magnet. Japanese Patent Application Laid-Open No. 7-212994 discloses that the magnetic pole orientation of the permanent magnet is such that the central portion in the circumferential direction is a parallel magnetic pole orientation, and both ends in the circumferential direction are outside the permanent magnet.
It is described that cogging torque is reduced by focusing on points.

[0004]

In the prior art,
Although the cogging torque and iron loss can be reduced by adjusting the magnetic pole orientation, there is a problem in that a sufficient induced voltage (main magnetic flux torque) cannot be obtained depending on the position of one outside point (focal point) where the magnetic flux is concentrated. .

[0005] This will be specifically described.

[0006] The magnetic flux of the permanent magnet is divided into an effective magnetic flux that generates main magnetic flux torque and an ineffective magnetic flux that generates cogging torque and iron loss. When the magnetic pole orientation is provided as in the conventional technique, the induced electromotive force waveform is approximated to a sine wave, thereby reducing the ineffective magnetic flux and reducing cogging torque and iron loss. However, since the magnetic pole orientation of all or one region of the permanent magnet is concentrated at one point, local magnetic saturation occurs due to the concentration of magnetic flux, thereby reducing the effective magnetic flux linking the armature winding. The main flux torque is reduced, and thus the motor efficiency is reduced. Further, if all the magnetic pole orientations are formed parallel to the d axis so as not to reduce the effective magnetic flux, the cogging torque and iron loss increase due to the ineffective magnetic flux, and the motor efficiency decreases.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a permanent magnet type rotating electric machine capable of reducing cogging torque and iron loss and obtaining a sufficient main magnetic flux torque. It is in.

[0008]

The feature of the present invention is that the magnetic pole orientation of the permanent magnet is set at a focal point substantially on the d-axis connecting the axis of the rotor and the circumferential center of the permanent magnet. In addition, the configuration is such that the focus of the magnetic pole orientation is distant from the both ends in the circumferential direction of the permanent magnet toward the center in the circumferential direction.

According to the present invention, the magnetic pole orientation of the permanent magnet is set on a substantially d-axis line connecting the axis of the rotor and the center of the permanent magnet in the circumferential direction, and from the both ends in the circumferential direction of the permanent magnet. The focus of the magnetic pole orientation is set farther toward the center in the circumferential direction. This suppresses the magnetic flux at both ends in the circumferential direction from becoming an ineffective magnetic flux rotating near the teeth surface of the stator core on the outer diameter side, thereby reducing cogging torque and iron loss, and focusing the magnetic pole orientation. By dispersing the magnetic flux, the concentration of the magnetic flux can be reduced, the effective magnetic flux can be increased, and the motor efficiency can be improved.

[0010]

1 to 3 show an embodiment of the present invention.

FIG. 1 is a radial sectional view of a rotor of a permanent magnet type rotating electric machine according to a first embodiment of the present invention, and FIG. 2 is a sectional view of the permanent magnet type rotating electric machine according to the first embodiment of the present invention. FIG. 1 is a sectional view in the axial direction (FIG. 1 is a sectional view taken along the line AA ′ in FIG. 2), and FIG. 3 is a sectional view in the radial direction of the permanent magnet type rotating electric machine according to the first embodiment of the present invention.

1 to 3, a permanent magnet type rotating electric machine 1 includes a stator 2 and a rotor 6 arranged on an inner peripheral side of a frame 14. The stator 2 includes a stator winding 5 wound around a plurality of slots 4 of a stator core 3. Rotor 6
Is mainly constructed by inserting a permanent magnet 9 into a permanent magnet insertion hole 8 formed in the rotor core 7.

An end plate core 10 (10) is provided on both sides of the rotor core 7.
a and 10b, and a permanent magnet insertion hole 8
Are provided with rivets (not shown) and the shaft 11 is fitted to form the rotor 6.

The rotor 6 is supported by bearings 12 (12a and 12b) fitted on both sides of a shaft 11 and end brackets 13 (13a and 13b). Is rotatably supported on the inner periphery of the stator 2 via a predetermined gap 18.

The permanent magnet 9 of the rotor 6 has a magnetic pole orientation described below. That is, the permanent magnet 9 (9a with a four pole machine,
9b, 9c, and 9d).
Magnetic pole orientations 15a, 15b, 15c, 15d, the center O of the shaft 11 and the circumferential center S on the outer peripheral side of the permanent magnet 9
Is the d-axis (perpendicular axis) and the focal point of the magnetic pole orientation 15 is P, the focal point Pa of the orientation 15a at both ends in the circumferential direction of the permanent magnet 9, and the focal point Pb of the magnetic pole orientation 15b from the center of 15a. , 15b, the focal point of the magnetic pole orientation 15c from the center is P
As shown in FIG. 1, c (the magnetic pole orientation 15 d is on the d-axis and the focal point is infinite), as shown in FIG. 1, the magnetic poles extend from both circumferential ends of the permanent magnet 9 toward the circumferential center S of the permanent magnet 9. The alignment is formed so that the focal point is far away.

The magnetic pole orientation according to the present invention will be described in comparison with the prior art.

FIG. 4 is a magnetic flux diagram of the permanent magnet type rotating electric machine when the magnetic pole orientation of the permanent magnet is formed parallel to the d-axis.

In FIG. 4, those having the same reference numerals as those in FIGS. In FIG. 4, it can be seen that a large amount of leakage magnetic flux leaks to the teeth 3a located between the poles. Leakage magnetic flux to the teeth 3a located between the poles increases the cogging torque and causes an increase in iron loss.

FIG. 5 shows a magnetic flux flow diagram in a permanent magnet type rotating electric machine in which the magnetic pole orientation mentioned as the prior art is concentrated at one point outside the permanent magnet.

In FIG. 5, the same reference numerals as those in FIGS. In FIG. 5, the magnetic pole orientation 15e at the circumferential end of the permanent magnet 9b is in a direction perpendicular to the q-axis (horizontal axis) connecting the permanent magnets 9a and 9b and the axis, and the focus thereof is It is formed so as to go to a point P on the d-axis. The other magnetic pole orientations 15f and 15g are also formed so that their focal points are directed to a point P on the d-axis.

FIG. 5 shows that no leakage magnetic flux passes through the teeth 3a located between the poles. Thereby, cogging torque and iron loss can be reduced. That is, in the prior art, cogging torque and iron loss can be reduced.

However, in such a pole orientation oriented to one focal point, the effective magnetic flux decreases. In order to quantitatively compare the effective magnetic fluxes of the present invention and the prior art, the angle between the magnetic pole orientation 15e at the circumferential end and the d-axis is defined as an orientation angle θ as shown in FIG. FIG. 6 shows the result of comparison between the induced electromotive force (induced voltage) of the present invention and the conventional technology when parameters are used. The induced electromotive force is an amount directly related to the effective magnetic flux.

In FIG. 6, when the orientation angle θ is 0 °, the magnetic pole orientation is formed parallel to the d-axis as shown in FIG. 4. At this time, the induced electromotive force becomes maximum. In FIG. 5, the orientation angle θ is 45 °.
In the focus orientation, the induced electromotive force is reduced by about 5% as compared with the parallel orientation, but is reduced by about 1% in the present invention. In the present invention at other orientation angles, the induced electromotive force is increased as compared with the unifocal orientation. According to the present invention, it is possible to improve the motor efficiency by increasing the induced electromotive force while reducing the cogging torque and iron loss.

FIG. 7 is a radial sectional view of a permanent magnet type rotating electric machine according to a second embodiment of the present invention.

In FIG. 7, the permanent magnets 9a, 9b, 9
The shapes of c and 9d are substantially arc-shaped convex shapes toward the outer circumference of the rotor 6 on both the outer circumference side and the inner circumference side with respect to the rotor 6. Also in FIG. 7, the motor efficiency can be improved by increasing the induced electromotive force while reducing cogging torque and iron loss as in FIG.

FIG. 8 is a radial sectional view of a permanent magnet type rotating electric machine according to a third embodiment of the present invention.

In FIG. 8, the permanent magnets 9a, 9b, 9
The shapes of c and 9d are substantially arc-shaped on the inner peripheral side with respect to the rotor 6 and inverted D-shaped with the outer peripheral side orthogonal to the d axis.
Also in FIG. 8, it is possible to improve the motor efficiency by increasing the induced electromotive force while reducing the cogging torque and the iron loss as in FIG.

FIG. 9 is a radial sectional view of a permanent magnet type rotary electric machine according to a fourth embodiment of the present invention.

In FIG. 9, the permanent magnets 9a, 9b, 9
The shapes of c and 9d are convex shapes that are substantially arc-shaped toward the axis of the rotor 6 on both the outer circumferential side and the inner circumferential side with respect to the rotor 6. Also in FIG. 9, the motor efficiency can be improved by increasing the induced electromotive force while reducing the cogging torque and iron loss as in FIG.

FIG. 10 is a radial sectional view of a permanent magnet type rotating electric machine according to a fifth embodiment of the present invention.

In FIG. 10, the permanent magnets 9a and 9a
e, 9b and 9f, 9c and 9g, 9d and 9h and a two-layer structure, and the shape thereof is substantially arc-shaped toward the axis of the rotor 6 on both the outer circumferential side and the inner circumferential side with respect to the rotor 6. It has a convex shape. Also in FIG. 10, the motor efficiency can be improved by increasing the induced electromotive force while reducing cogging torque and iron loss as in FIG.

FIG. 11 is a radial sectional view of a permanent magnet type rotating electric machine according to a sixth embodiment of the present invention.

In FIG. 11, a concentrated winding type stator 2 in which a stator winding 5 is wound around salient poles of a stator core 3 is used. Also in FIG. 11, it is possible to improve the motor efficiency by increasing the induced electromotive force while reducing cogging torque and iron loss as in FIG.

In FIG. 11, TU1 and TU2 are teeth wound with a U-phase winding, TV1 and TV2 are teeth wound with a V-phase winding, and TW1 and TW2 are wound with a W-phase winding. It is a tooth that was done.

[0035]

According to the present invention, the motor efficiency can be improved by increasing the induced electromotive force while reducing the cogging torque and iron loss by reducing the leakage flux to the teeth located at the magnetic poles. .

[Brief description of the drawings]

FIG. 1 is a radial sectional view of a rotor of a permanent magnet type rotating electric machine according to a first embodiment of the present invention.

FIG. 2 is an axial sectional view of the permanent magnet type rotating electric machine according to the first embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA ′ of FIG. 2;

FIG. 4 is a magnetic flux diagram of a permanent magnet type rotating electric machine in which the magnetic pole orientation of the permanent magnet is parallel to the d-axis.

FIG. 5 is a magnetic flux diagram of a conventional permanent magnet type rotating electric machine.

FIG. 6 is a comparison diagram of the orientation angle-induced electromotive force characteristics of the prior art and the first embodiment of the present invention.

FIG. 7 is a radial cross-sectional view of a rotor of a permanent magnet type rotating electric machine according to a second embodiment of the present invention.

FIG. 8 is a radial sectional view of a rotor of a permanent magnet type rotating electric machine according to a third embodiment of the present invention.

FIG. 9 is a radial sectional view of a rotor of a permanent magnet type rotating electric machine according to a fourth embodiment of the present invention.

FIG. 10 is a radial sectional view of a rotor of a permanent magnet type rotating electric machine according to a fifth embodiment of the present invention.

FIG. 11 is a radial sectional view of a rotor of a permanent magnet type rotating electric machine according to a sixth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Permanent magnet rotary electric machine, 2 ... Stator, 3 ... Stator iron core, 4 ... Slot, 5 ... Stator winding, 6 ... Rotor, 7 ...
Rotor core, 8: permanent magnet insertion hole, 9a to 9f: permanent magnet, 10a, 10b: end plate core, 11: shaft, 12
a, 12b: bearing, 13a, 13b: end bracket, 14: frame, 15a to 15g, 15a1,
15a2, 15b1, 15b2, 15c1, 15c2 ... magnetic pole orientation, 16a to 16c ... magnetic pole orientation, 18 ... gap, O ...
Center of rotation, P, Pa to Pc,... Focal point, S, intersection of d-axis and outer periphery of permanent magnet, TU1, TU2, teeth with U-phase winding, TV1, TV2, V-phase winding Wound teeth, TW1, TW2 ... Teeth with W-phase winding wound.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroki Yamamoto 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Mika Takahashi 7, Omikamachi, Hitachi City, Ibaraki Prefecture No. 1-1 In Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Keiji Noma 7-1, 1-1 Higashi Narashino, Narashino City, Chiba Prefecture Within the Industrial Equipment Group, Hitachi, Ltd. 7-1-1, Hitachi, Ltd. Industrial Equipment Group (72) Inventor Shoji Senoo 7-1-1, Higashi-Narashino, Narashino-shi, Chiba F-term in Hitachi Industrial Equipment Group, Ltd. 5H619 AA01 BB01 BB06 BB13 PP02 PP08 PP14 5H621 AA02 AA03 BB10 GA01 GA04 GA15 GA16 HH01 JK02 PP10 5H622 AA02 AA03 CA02 CA05 CA13 CB04 CB05 PP03 PP11 PP14 QB02 QB05

Claims (8)

[Claims] 1. A stator in which a stator winding is wound in a plurality of slots formed in a stator core, and a permanent magnet is housed in a plurality of permanent magnet insertion holes formed in a rotor core. In the permanent magnet type rotating electric machine having the rotor, the magnetic pole orientation of the permanent magnet is provided on a substantially d-axis line connecting the axis of the rotor and the circumferential center of the permanent magnet, and A permanent magnet type rotating electric machine characterized in that the magnetic pole orientation focus is distant from the circumferential both ends in the circumferential direction toward the center in the circumferential direction of the permanent magnet. 2. A stator in which a stator winding is wound around salient poles of a stator core, and a rotor in which permanent magnets are accommodated in a plurality of permanent magnet insertion holes formed in the rotor core. In the permanent magnet type rotating electric machine, the magnetic pole orientation of the permanent magnet is provided on a substantially d-axis line connecting the axis of the rotor and the circumferential center of the permanent magnet, and the magnetic pole orientation of the permanent magnet is controlled. A permanent magnet type rotating electric machine characterized in that the magnetic pole orientation focus is distant from both ends in the direction toward the center in the circumferential direction. 3. The permanent magnet according to claim 1, wherein the shape of the permanent magnet is a D-shape having a substantially arc shape on the outer peripheral side and a d-axis on the inner peripheral side with respect to the rotor. Permanent magnet type rotating electric machine. 4. The method according to claim 1, wherein the shape of the permanent magnet is a substantially arc-shaped convex shape toward the outer periphery of the rotor on both the outer peripheral side and the inner peripheral side with respect to the rotor. Characterized by a permanent magnet rotating electric machine. 5. The permanent magnet according to claim 1, wherein the shape of the permanent magnet is a substantially arc-shaped convex shape toward the axis of the rotor on both the outer circumferential side and the inner circumferential side with respect to the rotor. A permanent magnet type rotating electric machine characterized by the following. 6. The permanent magnet according to claim 1, wherein the shape of the permanent magnet is an inverted D shape having a substantially arc shape on the inner circumference side and an outer circumference side having a plane orthogonal to the d axis with respect to the rotor. Permanent magnet type rotating electric machine. 7. The permanent magnet according to claim 1, wherein the permanent magnet has a two-layer structure, and the shape of the permanent magnet is substantially both toward the axis of the rotor on both the outer circumferential side and the inner circumferential side with respect to the rotor. A permanent magnet type rotating electric machine having an arcuate convex shape. 8. The permanent magnet according to claim 1, wherein the magnetic pole orientation at both ends in the circumferential direction of the permanent magnet is a direction perpendicular to a q axis connecting between the permanent magnetic poles and the axis of the rotor. A permanent magnet type rotating electric machine characterized by having such a configuration.