JP2002325410A - Permanent magnet type dynamo-electric machine and compressor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet type dynamo-electric machine which is low in noises and a compressor using it. SOLUTION: The permanent magnet type dynamo-electric machine has a stator 5, on which an armature winding in a concentrated winding is executed so as to surround a plurality of teeth 8 formed to a stator core, and a rotor 1, in which permanent magnets 2 are housed in a plurality of permanent-magnet inserting holes formed to the rotor core 3. Arcuate sections and linear sections are formed to the teeth inner circumferential surfaces of the stator core, with 3.7<=(b/a)<=4.9 being established, when the width of the teeth is represented by (b) and the radial thickness of both end sections 8a of the front ends of the teeth by (a).

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 permanent magnet for a field in a rotor, and more particularly to a permanent magnet mounted in a compressor such as an air conditioner, a refrigerator and a freezer. The present invention relates to a magnet type rotating electric machine.

[0002]

2. Description of the Related Art Conventionally, in this type of permanent magnet type rotating electric machine, various measures have been taken to reduce noise, that is, torque pulsation. For example, 3-10
As described in Japanese Patent No. 6869, the center of the tooth tip is made concentric with the rotor core, and the torque pulsation is reduced by making both ends of the tooth tip straight, that is, away from the rotor.

[0003]

In the above prior art, the torque pulsation is reduced by moving both ends of the tooth tip away from the rotor, but in order to reduce noise, the torque pulsation must be significantly reduced. It was not sufficient to simply move both ends of the tooth tip away from the rotor.

[0004] It is an object of the present invention to provide a permanent magnet type rotating electric machine with low noise during rotation.

[0005]

One feature of the present invention is that
A stator in which concentrated armature windings are applied to surround a plurality of teeth formed in the stator core, and permanent magnets are accommodated in a plurality of permanent magnet insertion holes formed in the rotor core. In a permanent magnet type rotating electric machine having a rotor,
When the teeth inner surface of the stator core has two or more types of gap surfaces having different gap lengths, the width of the teeth is b, and the radial thickness of the end portion of the tooth tip is a, 3.7 ≦ ( b / a) ≦ 4.9.

Another feature of the present invention is that a stator in which concentrated winding armature winding is provided so as to surround a plurality of teeth formed in the stator core, and a plurality of permanent magnets formed in the rotor core. In a permanent magnet type rotating electric machine having a rotor in which a permanent magnet is accommodated in a magnet insertion hole, a stator core has an arc-shaped portion and a straight portion on an inner peripheral surface of a tooth, and the width of the tooth is b. The permanent magnet type rotary electric machine satisfies the relationship of 3.7 ≦ (b / a) ≦ 4.9, where a is the radial thickness of the end of the tooth.

[0007] Still another feature of the present invention is that a stator provided with concentrated winding armature winding so as to surround a plurality of teeth formed on the stator core, and a plurality of stators formed on the rotor core. In a permanent magnet type rotating electric machine having a rotor in which a permanent magnet is accommodated in a permanent magnet insertion hole, an arc-shaped portion and a straight portion are provided on the inner peripheral surface of the teeth of the stator core, and the width of the teeth is b. When the radial thickness of the end portion of the tooth tip is a, the relationship of 3.7 ≦ (b / a) ≦ 4.9 is satisfied, and the arc-shaped portion of the inner peripheral surface of the tooth of the stator core is the rotor. In the permanent magnet type rotating electric machine, the angle formed with respect to the axis center of the rotor is smaller than the angle formed by the teeth width with respect to the axis center of the rotor.

[0008] According to the above configuration, since the shape of the teeth tips of the stator core is optimized, a low-noise permanent magnet type rotating electric machine can be provided.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. In each drawing, common reference numerals indicate the same items. In addition, although a permanent magnet type rotating electric machine having four poles and six slots has been described as an example, the present invention is not limited to this.

FIG. 1 shows a sectional structure of a permanent magnet type rotating electric machine according to an embodiment of the present invention. FIG. 2 is a diagram simulating the flow of magnetic flux according to one embodiment of the present invention. FIG. 3 is a noise measurement result of a rotating electric machine showing a relationship between a tooth tip shape and noise according to an embodiment of the present invention.

In FIG. 1, the permanent magnet type rotating electric machine includes a stator 5 and a rotor 1, and an iron core of the stator 5 is formed by six teeth 8 and a core back 6. Further, the rotor 1 is provided with holes for embedding permanent magnets in the rotor core 3,
A permanent magnet 2 is buried therein, and a concentrated winding armature winding (not shown) is wound around the stator 5 so as to surround the teeth 8 in the slot 7. Here, the inner peripheral surface of the tooth 8 is constituted by an arc-shaped portion and a linear portion, the gap length at the center 8b side of the tooth 8 is g1, the end 8a of the tooth 8a.
When the gap length on the side is g2, g1 <g2. Further, the axis center of the rotor 1 is O, and the arc-shaped portion AB is the axis center O.
Α is defined as α and β is defined as the angle formed by the teeth width CD with respect to the axial center O.

One of the problems with the permanent magnet type rotating electric machine is noise during rotation, which is caused by torque pulsation. The torque pulsation is generated due to the harmonic magnetic flux in the machine. If the magnetic flux distribution in the machine, that is, the magnetic flux distribution in the air gap is made smooth, the torque pulsation is reduced.

Considering the flow of the magnetic flux, as shown in FIG. 2, the magnetic flux φ incident on the stator 5 from the rotor 1 side is transmitted from both ends 8a and the central portion 8b of the tooth tip to the tooth 8 It passes through the root and the core back 6 in this order. As described above, there is almost no magnetic flux incident from the slot opening 9, and the magnetic flux is concentrated and incident on the end 8 a and the center 8 b of the tooth tip. Therefore, in order to smooth the magnetic flux distribution in the air gap, To some extent (reduce) the magnetic flux incident from the end 8a of the tooth tip
There is a need. Therefore, generally, both ends 8a of the tooth tip are moved away from the rotor 1 in order to reduce torque pulsation,
As g1 <g2, the magnetic flux incident from both ends 8a of the tooth tip is reduced. However, the gap length (g1, g
There is a limit only by the adjustment according to 2), and the noise at the time of rotation cannot be sufficiently reduced.

Therefore, it has been found that the end 8a of the tip of the tooth is appropriately saturated to suppress the magnetic flux incident from the end 8a of the tip of the tooth, and the distribution of the gap magnetic flux should be made smooth. That is, by optimizing the ratio of the radial thickness a of the root of the tooth tip end 8a to the width b of the tooth 8, the distribution of the gap magnetic flux becomes smooth, and the pulsating torque can be significantly reduced. Was.

Therefore, an experiment was conducted using permanent magnet type rotating electric machines having different b / a. FIG. 3 shows the noise measurement results. When the permanent magnet type rotating electric machine is rotating, the sound is low when the sound is low, and when the sound is loud, the sound is indicated by the cross. (B / a) to 3.
When 7 ≦ (b / a) ≦ 4.9, the sound during rotation was reduced.

Here, the reason why the noise was large when (b / a) was larger than 4.9 was that since a was smaller than b, the magnetic saturation at both ends 8a of the tooth tip was remarkable.
It is considered that the magnetic flux entering from both ends 8a of the tooth tip becomes extremely small, and the magnetic flux entering the stator 5 from the rotor 1 side concentrates on the central portion 8b of the tooth tip, so that the distribution of the magnetic flux is not smooth. .

On the other hand, when (b / a) was smaller than 3.7, the reason why the noise was large was that a was larger than b, so that the magnetic saturation at both end portions 8a of the tooth tip was small, and the gap length g1 and Although the difference in the incident magnetic flux due to the difference in g2 is observed, it is considered that the difference between the magnetic flux incident from the end 8a and the center 8b of the tooth tip is small and the distribution of the magnetic flux is not smooth.

That is, by setting 3.7 ≦ (b / a) ≦ 4.9, the magnetic flux density distribution in the gap becomes smooth,
It is considered that torque pulsation is reduced and noise is also reduced.

As shown in the figure, when the inner peripheral surface of the tooth 8 is formed of an arc portion and a straight portion, the range of the angle α formed by the arc portion AB with respect to the axis center O is an important factor. It is. As a result of various experiments, α is smaller than the angle β formed by the tooth width CD with respect to the axis center O (α <β).
At times, the noise was even smaller.

FIG. 4 is a sectional view of a compressor according to an embodiment of the present invention. The compressor has a fixed scroll member 1
And a spiral wrap 12 standing upright on the end plate 11 of the orbiting scroll member 13.
The compression operation is performed by rotating the orbiting scroll member 13 by the crankshaft 4. The compression chamber 16 (16a, 16a) formed by the fixed scroll member 10 and the orbiting scroll member 13
b,...), the compression chamber located on the outermost side is
It moves toward the center of both scroll members 10 and 13 with the orbital movement, and the volume gradually decreases. Compression chamber 16
When a and 16b reach the vicinity of the center of both scroll members 10 and 13, the compressed gas in both compression chambers 16 is discharged from discharge port 17 communicating with compression chambers 16. The discharged compressed gas passes through the fixed scroll member 10 and a gas passage (not shown) provided in the frame 18, reaches the compression container 19 below the frame 18, and has a discharge pipe provided on a side wall of the compression container 19. From 20 is discharged outside the compressor. In this compressor, a driving motor 21 is enclosed in the pressure vessel 19, and rotates at a rotation speed controlled by a separate inverter (not shown) to perform a compression operation. Here, the drive motor 21 is a permanent magnet type rotating electric machine including the stator 5 and the rotor 1.

The compressor is used as a driving source for an air conditioner, a refrigerator, a freezer, or the like. However, since it operates all year, it is the most important product for saving energy due to the problem of global warming. When a permanent magnet type rotating electric machine is used as this drive source, energy saving can be achieved by increasing the efficiency of the rotating electric machine, but it cannot be adopted unless noise is reduced. However, when the permanent magnet type rotating electric machine of the present invention is used as a drive source, noise can be reduced and environmental problems can be solved. Therefore, a compressor that can achieve high efficiency and energy saving can be provided.

If the compressor using the permanent magnet type rotating electric machine according to the present invention as a drive source is adopted for an air conditioner, an air conditioner that satisfies top runner regulations can be provided.

If a compressor using the permanent magnet type rotating electric machine according to the present invention as a drive source is employed in a refrigerator, an electric refrigerator which satisfies top runner regulations can be provided.

If a compressor using the permanent magnet type rotating electric machine of the present invention as a drive source is employed in a freezer, it is possible to provide an energy-saving freezer.

[0025]

As described above, according to the present invention, since the sound during rotation is reduced in the permanent magnet type rotating electric machine, a low noise permanent magnet type rotating electric machine and a compressor using the same can be provided. .

[Brief description of the drawings]

FIG. 1 is a sectional structure of a permanent magnet type rotating electric machine showing one embodiment of the present invention.

FIG. 2 is a diagram simulating the flow of magnetic flux according to one embodiment of the present invention.

FIG. 3 is a graph showing a relationship between a tooth tip shape and noise according to an embodiment of the present invention.

FIG. 4 is a cross-sectional structure of a compressor according to one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... rotor, 2 ... permanent magnet, 3 ... rotor core, 4 ... shaft, 5 ... stator, 6 ... core back, 7 ... slot, 8
... Teeth, 8a: End of tooth tip, 8b: Center of tooth tip, 9: Slot opening, 10: Fixed scroll member, 11, 14: End plate, 12, 15: Wrap,
DESCRIPTION OF SYMBOLS 13 ... Orbiting scroll member, 16 ... Compression chamber, 17 ... Discharge port, 18 ... Frame, 19 ... Compression container, 20 ... Discharge pipe, 21 ... Driving motor, 22 ... Armature winding, 23 ... Oil reservoir part, 24 ... oil holes, 25 ... sliding bearings.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Ryoichi Takahata 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Satoshi Kikuchi 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd., Hitachi Research Laboratory (72) Inventor Mika Takahashi 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Hitachi Research Laboratory, Ltd. (72) Inventor Hiroshi Hirayama Shimotsuga-gun, Tochigi Prefecture 800, Odaira, Tomita, Hitachi, Ltd.Cooling and Cooling Division, Hitachi, Ltd. 800, Tomita, Townhouse, Hitachi, Ltd.Cooling and Heating Division (72) Inventor: Shoji Senoo Narashino-shi, Chiba 7-1-1 Shino Hitachi Drive Systems, Hitachi, Ltd. (72) Inventor Keiji Noma 7-1-1 Higashi Narashino, Narashino-shi, Chiba F-term, Hitachi Drive Systems, Ltd. 3H003 AA05 AB03 AC03 CF04 3H029 AA02 AA14 AB03 BB21 CC07 CC27 5H002 AA05 AB04 AE07 5H621 AA02 BB07 BB10 GA00 GA04 GA12 HH01

Claims (7)

[Claims] 1. A stator in which concentrated armature winding is provided so as to surround a plurality of teeth formed in a stator core, and a permanent magnet is inserted into a plurality of permanent magnet insertion holes formed in a rotor core. A permanent magnet type rotating electric machine having a rotor in which magnets are accommodated, wherein the stator core has two or more types of gap surfaces having different gap lengths on inner circumferential surfaces of the teeth, and the width of the teeth is b, A permanent magnet type rotating electric machine characterized by satisfying a relationship of 3.7 ≦ (b / a) ≦ 4.9, where a is a radial thickness of a root of an end portion of a tooth tip. 2. A stator having a concentrated winding armature winding surrounding a plurality of teeth formed on a stator core, and a plurality of permanent magnets inserted into a plurality of permanent magnet insertion holes formed on a rotor core. A permanent magnet type rotating electric machine having a rotor in which a magnet is accommodated, wherein the stator core has an arc-shaped portion and a straight portion on an inner peripheral surface of the tooth, the width of the tooth is b, and the tip of the tooth is 3. The permanent-magnet-type electric rotating machine according to claim 1, wherein a relation of 3.7 ≦ (b / a) ≦ 4.9 is satisfied, where a is the radial thickness of the root of the end portion. 3. An angle between an arc-shaped portion of an inner peripheral surface of a tooth of the stator core and an axial center of the rotor, and a width of the tooth with respect to an axial center of the rotor. A permanent magnet type rotating electric machine characterized by being smaller than the angle formed. 4. A compressor having the permanent magnet type rotating electric machine according to claim 1 as a drive source. 5. An air conditioner having the compressor according to claim 4. 6. A refrigerator having the compressor according to claim 4. 7. A freezer having the compressor according to claim 4.