JP2001178037A - Permanent-magnet dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet dynamo-electric machine where vibration or noise is not increased with increase in armature current. SOLUTION: A permanent-magnet dynamo-electric machine is provided with a stator with armature winding installed in a plurality of slots formed in its stator core and a rotor with a permanent magnet held in a plurality of permanent magnet insertion holes formed in its rotor core. In the electric rotating machine, the permanent magnets are so formed that they are substantially in an arc shape, protruded toward the outside radius of the rotor core and further substantially in an arc shape, protruded toward the inside radius of the rotor core. As a result, the torque resulting from magnet magnetic flux is increased and further the armature reaction magnetic flux produced by armature currents is reduced. Thus the permanent-magnet electric rotating machine allows vibration and noise to be reduced, without having to reduce the torque generated by the dynamo-electric machine.

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 Conventionally, permanent magnet rotary electric machines employ various shapes for permanent magnets. For example, JP-A-6-339
In the permanent magnet type rotating electric machine described in Japanese Patent No. 241, the cross-sectional shape of the permanent magnet accommodated in the plurality of permanent magnet insertion holes formed in the rotor core is formed in an arc shape in which the arc is formed.
The protrusions of these permanent magnets are arranged so as to face the inner diameter side of the rotor iron core to improve the characteristics. Also, JP-A-6-3
In the permanent magnet type rotating electric machine described in Japanese Patent No. 39238, the cross-sectional shape of the permanent magnet accommodated in a plurality of permanent magnet insertion holes formed in the rotor core is formed in an arc shape that is convex toward the inner diameter side of the rotor core. The outer diameter side is formed in a U-shape to reduce the cogging torque.

[0003]

In the above prior art, the convex portion of the cross section of the permanent magnet is arranged so as to face the inner diameter side of the rotor core, so that the characteristics can be improved and the cogging torque can be reduced. However, since the rotor core exists at a position facing the armature winding, a large amount of armature reaction magnetic flux generated by the armature current is generated, and there is a problem that vibration and noise increase as the armature current increases.

The present invention has been made in view of the above points. It is an object of the present invention to oscillate as the armature current increases.
An object of the present invention is to provide a permanent magnet type rotating electric machine that does not increase noise.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a stator in which an armature winding is provided in a plurality of slots formed in a stator core, and a plurality of permanent magnet insertion holes formed in a rotor core. In a permanent magnet type rotating electric machine having a rotor in which a permanent magnet is housed, the shape of the permanent magnet is formed in a substantially arc shape convex toward the outer diameter side of the rotor core,
This is achieved by forming the rotor core in a substantially arc shape that is convex toward the inner diameter side of the rotor core.

[0006] The armature current becomes a torque current, and the magnitude of the armature current affects the magnitude of the output. From the viewpoint of characteristics, it is better to generate a large amount of magnetic flux due to the armature current.Therefore, as shown in the prior art, a rotor core on the armature side exists at a position opposing the armature winding, and the reluctance A method that effectively utilizes the torque is adopted. However, the present inventors have found that the magnetic flux created by the armature winding becomes pulsating magnetic flux in the gap between the stator and the rotor, and the commutation ripple magnetic flux increases due to the increase in the armature current.・ Discovered a technical issue that increases noise.
The present invention has been made to solve this problem, and the shape of the permanent magnet is formed in a substantially arc shape that is convex toward the outer diameter side of the rotor core, and is convex toward the inner diameter side of the rotor core. By forming the iron core on the outer diameter side of the rotor, the so-called bridge, and making the magnet thicker by forming a substantially arc shape of the above, the torque due to the magnet flux is increased, and the armature reaction created by the armature current Since the magnetic flux is reduced, vibration and noise can be reduced without reducing the torque generated by the rotating electric machine.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a diagram showing a radial cross-sectional shape of a permanent magnet type rotating electric machine according to one embodiment of the present invention. As shown in FIG. 1, a permanent magnet type rotating electric machine 1 includes a stator 6 and a rotor 7.
Having. The stator 6 includes armature windings 5 in a plurality of slots 4 formed with a plurality of teeth 3 of the stator core 2.
(Distributed winding of the U-phase winding 5A, the V-phase winding 5B, and the W-phase winding 5C). The rotor 7 has a permanent magnet 10 (shown here with four poles) arranged in a permanent magnet insertion hole 9 provided in the rotor core 8 and a shaft fitting for fitting to a shaft (not shown). And a hole 11.

In FIG. 1, the permanent magnet 10 is formed as follows. The permanent magnet 10 has a substantially arc shape that is convex on the outer diameter side and a substantially arc shape that is convex on the inner diameter side, and the d-axis (the axis of the magnetic pole is inserted) (?? Answer: Please join.) The side is the thickest. Here, the definition of the convex shape is linked to the shape of the convex lens, and refers to a case where the thickness on the d-axis side is greater than the distance between the poles on a line orthogonal to the d-axis. As a result, the circumferential width of the core 13 between the magnetic poles is large on the outside diameter side and narrow on the inside diameter side. When the thickness of the d-axis magnet is Lm and the length of the teeth 3 is Lt, Lm
/Lt>1.3. Here, the length Lt of the teeth 3 affects the area of the slot 4 if they have the same diameter. In other words, the length Lt is proportional to the number of turns of the armature winding 5, that is, the magnitude of the armature reaction. Conversely, Lm /
The relationship of Lt> 1.3 ensures a sufficient magnet thickness of the permanent magnet 10 to overcome the armature reaction, and reduces the effect of the armature reaction.

Further, the outer circumference of the permanent magnet 10 has a substantially arc-shaped perimeter convex on the outer diameter side, and the substantially arc-shaped perimeter of the protrusion protruding on the inner diameter side has a length L.
b, the relationship of Lb> Lu is set, and the permanent magnet 1
The setting is such that the magnetic flux of 0 is used effectively. Thereby, the torque by the magnetic flux of the permanent magnet 10 can be increased.

In the permanent magnet type rotating electric machine 1 having the permanent magnet 10 as described above, when a torque generating current is supplied to the armature winding 5, the armature reaction magnetic flux φag
A path (not shown) passes through only the bridge portion 12 on the outer diameter side of the permanent magnet 10 and the core 13 between the magnetic poles between the permanent magnets 10. The minimum thickness Wb of the bridge portion 12 in the radial direction is set to 85% or more of the thickness of the iron core material in consideration of the accuracy and life of the mold. For example, when the thickness of the iron core material is 0.5 mm, it is set to 0.43 mm. Therefore, when an armature current flows through the armature winding 5, an armature reaction magnetic flux φag is generated. However, since the bridge section 12 and the core 13 between the magnetic poles have a small magnetic path cross-sectional area, magnetic saturation occurs immediately. Even when an armature current is passed, the gap magnetic flux density between the stator 6 and the rotor 7 does not change, and the armature current is increased, thereby preventing an increase in vibration and noise.

FIG. 2 is a diagram showing a sectional shape in the rotor axial direction of a permanent magnet type rotating electric machine according to one embodiment of the present invention. FIG. 3 is a view showing a rotor core shape of the permanent magnet type rotating electric machine according to one embodiment of the present invention. FIG.
The sectional shape at -A 'is shown. FIG. 3B shows a cross-sectional shape taken along the line BB ′ of FIG. As shown in FIGS. 2 and 3, the rotor 7 includes a rotor core 8 including a permanent magnet 10 disposed in the permanent magnet insertion hole 9 and a shaft fitting hole 11 having an outer diameter d1; The boss rotor core 14 includes a permanent magnet 10 disposed therein and a boss hole 15 having an outer diameter d2. And the boss hole 1 of the boss rotor core 14
5 (t in FIG. 2 or FIG. 3) is set to 2 mm or less. Thereby, even if the boss hole 15 is provided, the magnet thickness Lm and the length Lt of the teeth 3 are set to be Lm / Lt> 1.3.
And the effect shown in FIG. 1 can be obtained. Note that the boss holes 15 are formed so that the permanent magnet type rotating electric machine 1 of the present invention can be applied to a compressor (not shown).

FIG. 4 is a diagram showing a radial cross section of a permanent magnet type rotating electric machine according to another embodiment of the present invention. 4, the same reference numerals are given to the same or equivalent components as those in FIG. FIG. 4 differs from FIG. 1 in the configuration of the rotor 7.
That is, the rotor 7 includes the permanent magnet 16 and the shaft fitting hole 11 arranged in the permanent magnet insertion hole 9 provided in the rotor core 8. The permanent magnet 16 has a substantially arc shape that is convex on the outer diameter side and a substantially arc shape that is convex on the inner diameter side, and has the thickest d-axis side, but has a substantially arc shape that is convex on the outer diameter side. Is reduced, the bridge thickness Wb2 between the poles is larger than the bridge thickness Wb1 on the d-axis, so that the slit 17 is provided between the poles. As a result, when a torque generating current is supplied to the armature winding 5, the armature reaction magnetic flux φa
The path through which g (not shown) passes is only the bridge portion 12 on the outer diameter side of the permanent magnet 10. Therefore, when the armature current flows through the armature winding 5, an armature reaction magnetic flux φag is generated. However, since the magnetic path cross-sectional area of the bridge portion 12 is small, magnetic saturation occurs immediately, and an armature current larger than that is passed. Also, the gap magnetic flux density between the stator 6 and the rotor 7 does not change, and the armature current can be increased to prevent an increase in vibration and noise. Although not shown, the boss rotor core 1 shown in FIG.
4 may be provided.

FIG. 5 is a radial sectional view of a permanent magnet type rotating electric machine according to another embodiment of the present invention. In FIG. 5, the same or corresponding components as those in FIG. 1 are denoted by the same reference numerals. FIG. 5 differs from FIG. 1 in the configuration of the rotor 7. That is, the rotor 7 includes a permanent magnet 18 and a shaft fitting hole 11 arranged in a permanent magnet insertion hole 9 provided in the rotor core 8. The permanent magnet 18 has a substantially arc shape with a convex shape on the outer diameter side and a U-shape with a convex shape on the inner diameter side, and the d axis (?? is not shown in the figure. Please join.) The side is the thickest. As a result, the circumferential width of the core 13 between the magnetic poles is large on the outside diameter side and narrow on the inside diameter side.
When the thickness of the d-axis magnet is Lm and the length of the teeth 3 is Lt, the relationship of Lm / Lt> 1.3 is set. Thus, the relationship of Lm / Lt> 1.3 ensures a sufficient magnet thickness to overcome the armature reaction and reduces the effect of the armature reaction.

When the outer circumference of the permanent magnet 18 has a substantially arc-shaped circumference protruding toward the outer diameter side of Lu, and the circumference of the U-shape convexly formed on the inner diameter side is Lb, the relationship of Lb> Lu is satisfied. Since the setting is made so that the magnetic flux of the permanent magnet 18 is effectively used, the torque due to the magnetic flux of the permanent magnet 18 can be increased.

In the permanent magnet type rotating electric machine 1 having the above-described magnet shape, when a torque generating current is supplied to the armature winding 5, the path through which the armature reaction magnetic flux φag (not shown) passes is a permanent magnet 18. Only the core 13 between the magnetic poles between the bridge portion 12 on the outer diameter side and the permanent magnet 18. For this reason,
When an armature current flows through the armature winding 5, an armature reaction magnetic flux φag is generated.
However, since the magnetic path cross-sectional area is small, magnetic saturation is immediately reached, and even when an armature current is further applied, the gap magnetic flux density between the stator 6 and the rotor 7 does not change. Noise can be prevented from increasing.

FIG. 6 is a radial sectional view of a permanent magnet type rotating electric machine according to still another embodiment of the present invention. 6, the same reference numerals are given to the same or equivalent components as those in FIG. FIG. 6 differs from FIG. 1 in the configuration of the rotor 7. That is, the rotor 7 includes the permanent magnet 19 and the shaft fitting hole 11 arranged in the permanent magnet insertion hole 9 provided in the rotor core 8. The permanent magnet 19 has a substantially arc shape that is convex on the outer diameter side and a U-shape that is convex on the inner diameter side, and has the thickest d-axis side, but has a substantially circular shape that is convex on the outer diameter side. As a result of reducing the arc-shaped diameter, the bridge portion thickness Wb2 between the poles becomes larger than the bridge portion thickness Wb1 on the d-axis, so that the slit 17
Is provided. As a result, when a torque generating current is supplied to the armature winding 5, the path through which the armature reaction magnetic flux φag (not shown) passes is only the bridge portion 12 on the outer diameter side of the permanent magnet 19. Flows through the armature winding 5, an armature reaction magnetic flux φag is generated. However, since the magnetic path cross-sectional area of the bridge portion 12 is small, magnetic saturation occurs immediately, and even when an armature current exceeding this value flows, the gap magnetic flux density between the stator 6 and the rotor 7 does not change. It is possible to prevent increase in vibration and noise. Although not shown, the boss rotor core shown in FIG. 2 may be provided in the configuration of FIG.

FIG. 7 is a radial sectional view of a concentrated winding permanent magnet type rotating electric machine according to still another embodiment of the present invention. 7, the same or equivalent components as those in FIG. 1 are denoted by the same reference numerals. FIG. 7 differs from FIG. 1 in the configuration of the stator 6. That is, the stator 6 winds concentrated armature windings 5 (U-phase windings 5A, V-phase windings 5B, W-phase windings 5C) in the slots 4 so as to surround the teeth 3 of the stator core 2. It was dressed. The concentrated winding can shorten the coil end length as compared with the distributed winding, so that the copper loss can be reduced together with the effect of FIG. 1 and the characteristics of the permanent magnet type rotating electric machine 1 can be improved. Although not shown, the boss rotor core shown in FIG. 2 may be provided in the configuration of FIG.

FIG. 8 is a radial sectional view of a concentrated winding permanent magnet type rotating electric machine according to still another embodiment of the present invention. In FIG. 8, the same or corresponding components as those in FIG. 5 are denoted by the same reference numerals. FIG. 8 differs from FIG. 5 in the configuration of the stator 6. That is, the stator 6 winds concentrated armature windings 5 (U-phase windings 5A, V-phase windings 5B, W-phase windings 5C) in the slots 4 so as to surround the teeth 3 of the stator core 2. It was dressed. The concentrated winding can shorten the coil end length as compared with the distributed winding, so that the copper loss can be reduced together with the effect of FIG. 1 and the characteristics of the permanent magnet type rotating electric machine 1 can be improved. Although not shown, it goes without saying that the boss rotor core shown in FIG. 2 may be provided in the configuration of FIG.

As described in detail above, the shape of the permanent magnet is
The rotor core is formed in a substantially circular arc shape protruding toward the outer diameter side of the rotor core, and is formed in a substantially circular arc shape protruding toward the inner diameter side of the rotor core, so that the core on the rotor outer diameter side is formed. Department,
The so-called bridge is thinned and the magnet thickness is increased, so that the torque due to the magnet flux is increased, and the armature reaction flux created by the armature current is reduced, so that the torque generated by the rotating electric machine is not reduced. A permanent magnet type rotating electric machine capable of reducing vibration and noise can be provided.

[0021]

According to the present invention, it is possible to provide a permanent magnet type rotating electric machine in which vibration and noise do not increase as the armature current increases.

[Brief description of the drawings]

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

FIG. 2 is an axial cross-sectional shape of a permanent magnet type rotating electric machine according to one embodiment of the present invention.

FIG. 3 shows a rotor core shape of a permanent magnet type rotating electric machine according to one embodiment of the present invention.

FIG. 4 is a radial sectional view of a permanent magnet type rotating electric machine according to another embodiment of the present invention.

FIG. 5 is a radial sectional view of a permanent magnet type rotating electric machine according to another embodiment of the present invention.

FIG. 6 is a radial cross-sectional view of a permanent magnet type rotating electric machine according to still another embodiment of the present invention.

FIG. 7 is a radial cross-sectional view of a concentrated winding permanent magnet type rotating electric machine according to still another embodiment of the present invention.

FIG. 8 is a radial cross-sectional view of a concentrated winding permanent magnet type rotating electric machine according to still another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Permanent magnet rotary electric machine, 2 ... Stator iron core, 3 ... Teeth, 4 ... Slot, 5 ... Armature winding, 6 ... Stator, 7 ...
Rotor, 8 ... Rotor core, 9 ... Permanent magnet insertion hole, 10 ...
Permanent magnet, 11: shaft fitting hole, 12: bridge part,
13: core between magnetic poles, 14: boss rotor core, 15: boss hole, 16: permanent magnet, 17: slit, 18, 19: permanent magnet.

 ──────────────────────────────────────────────────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 the Industrial Equipment Group, Hitachi, Ltd. 5H002 AA04 AB06 AB07 AB07 AE07 AE08 5H619 AA01 BB01 BB06 BB13 BB15 PP01 PP02 PP06 PP08 PP14 5H621 AA02 GA01 GA04 GB06 HH01 JK02 5H622 AA02 CA02 CA05 CA13 CB04 CB05 PP03 PP10 PP11 QB05

Claims (13)

[Claims] 1. A stator in which an armature winding is provided in a plurality of slots formed in a stator core, and a permanent magnet is contained 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 shape of the permanent magnet is formed in a substantially arc shape convex toward the outer diameter side of the rotor core, and the shape of the permanent magnet is directed toward the inner diameter side of the rotor core. A permanent magnet type rotating electric machine characterized in that it is formed in a substantially arc shape with a convex shape. 2. A stator in which an armature winding is provided in a plurality of slots formed in a stator core, and permanent magnets are accommodated in a plurality of permanent magnet insertion holes formed in a rotor core. And a permanent magnet type rotating electric machine having a rotor, wherein the shape of the permanent magnet is formed in a substantially arc shape convex toward the inner and outer diameter sides of the rotor core, and the substantially arc shape is formed on the outer diameter side. A permanent magnet type rotating electric machine characterized in that a substantially arc-shaped circumference on the inner diameter side is longer than a circumference. 3. A stator in which an armature winding is provided in a plurality of slots formed in a stator core, and a permanent magnet is accommodated in a plurality of permanent magnet insertion holes formed in a rotor core. In the permanent magnet type rotating electric machine having a rotor, the shape of the permanent magnet is formed in a substantially arc shape convex toward the inner and outer diameter sides of the rotor core, and a shaft is provided at one end of the rotor core. A boss rotor iron core larger than the inner diameter to be fitted is provided, and the minimum radial thickness of the boss rotor iron core is 2 mm.
A permanent magnet rotating electric machine characterized by the following settings. 4. The permanent magnet according to claim 1, wherein a circumferential width of the pole core located between the poles of the permanent magnet is wider on an inner diameter side than on an outer diameter side. Rotary electric machine. 5. A permanent magnet type rotating electric machine according to claim 1, wherein a slit is formed on the outer diameter side of the pole core located between the poles of the permanent magnet. 6. A stator in which an armature winding is provided in a plurality of slots formed in a stator core, and a permanent magnet is accommodated 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 shape of the permanent magnet is formed in a substantially arc shape convex toward the outer diameter side of the rotor core, and the shape of the permanent magnet is directed toward the inner diameter side of the rotor core. A permanent magnet type rotating electric machine formed in a U-shape. 7. A stator in which an armature winding is provided in a plurality of slots formed in a stator core, and a permanent magnet is accommodated 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 shape of the permanent magnet is formed in a substantially arc shape convex toward the outer diameter side of the rotor core, and the shape of the permanent magnet is directed toward the inner diameter side of the rotor core. A permanent-magnet-type rotating electric machine characterized in that it is formed in a U-shape, and the circumference of the U-shape on the inner diameter side is made longer than the circumference of the substantially arc shape on the outer diameter side. 8. A stator in which armature windings are provided in a plurality of slots formed in a stator core, and permanent magnets are contained 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 shape of the permanent magnet is formed in a substantially arc shape convex toward the outer diameter side of the rotor core, and the shape of the permanent magnet is directed toward the inner diameter side of the rotor core. A boss rotor core formed in a U-shape and having an inner diameter larger than an inner diameter to be fitted to a shaft is provided at one end of the rotor core, and the minimum radial thickness of the boss rotor core is set to 2 mm or less. A permanent magnet type rotating electric machine characterized by the following. 9. The method according to claim 6, wherein the circumferential width of the pole core located between the poles of the permanent magnet is wider on the inner diameter side than on the outer diameter side. Permanent magnet type rotating electric machine. 10. A permanent magnet type rotating electric machine according to claim 6, wherein a slit is formed on an outer diameter side of the pole core located between the poles of the permanent magnet. 11. The permanent magnet type rotating device according to claim 1, wherein said armature winding is a concentrated winding wound around teeth of said stator core. Electric machine. 12. A method according to claim 1, wherein when a thickness of said permanent magnet is Lm and a radial length of said teeth of said stator core is Lt, Lm / Lt>
1.3 A permanent magnet type rotating electric machine characterized by the above. 13. The permanent magnet according to claim 1, wherein Lb> Lu where Lu is the outer circumferential length of the permanent magnet and Lb is the inner circumferential length of the permanent magnet. Permanent magnet type rotating electric machine.