JP4210811B2 - Permanent magnet motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stator structure of an inner rotor type permanent magnet motor used for a compressor such as an air conditioner or an electric refrigerator, and more particularly to a permanent magnet motor that realizes cost reduction and high efficiency of a motor. .
[0002]
[Prior art]
The permanent magnet motor includes a rotor (for example, the number of poles 4) that forms a magnetic field using a permanent magnet on the inner side, and a stator that is positioned outside the rotor and generates a rotating magnetic field, for example, six slots. 6 has the structure shown in FIG.
[0003]
6, the stator 1 has a donut-shaped yoke portion outer periphery as a circular, teeth 2 extend toward the center from the yoke section, and is six formed at equal intervals in the circumferential direction. Moreover, the edge part of the tooth | gear 2 is the shape extended in the left-right direction in the circumferential direction, and the slot 3 of the same shape is formed in the circumferential direction at equal intervals between the adjacent teeth | gears 2. FIG. In addition, 4 is a rotor and 5 is a shaft.
[0004]
The stator 1 of the permanent magnet motor is formed by laminating a large number of core sheets 1a made by punching electromagnetic steel sheets into the shape shown in FIG. 6, and concentrated winding is directly applied to each tooth 2 via the adjacent slots 3 by a winding machine. However, it is necessary to insulate the groove of the slot 3 of the stator 1 in advance.
As this insulation method, there is a method in which a thin bobbin formed of a synthetic resin (PSS (polyphenylene sulfide) or the like) on the stator 1 is fitted into the groove of the slot 3 from both the upper and lower sides of the core. Insulation using this synthetic resin The method is inevitably expensive.
Therefore, there is a method using an inexpensive PET film. In the insulation method using this PET film, a slot liner with cuffs is formed with the PET film, and this is installed in the groove of the slot 3.
[0005]
However, when the electric motor having the stator 1 having the above structure is used for an air conditioner or a compressor of an electric refrigerator, since the outer periphery of the stator 1 is circular, there is no gap on the outer peripheral side. The streets are not so good, and the quality and performance of the compressor is inevitably inferior.
[0006]
Further, since the end portion of the tooth 2 of the stator 1 extends along the outer periphery of the rotor 4, the winding tends to come off from the tooth 2 when concentrated winding is performed on the tooth 2. Moreover, since the yoke side of the groove of the slot 3 is an arc along the outer peripheral side of the stator 1, the number of turns of the winding is limited, and the winding is on the inner diameter side (rotor 4 side) of the stator 1. The distance between the winding and the rotor 4 tends to be less than the specified value.
[0007]
Therefore, for example, as shown in FIG. 7, the outer periphery of the stator 6 has a substantially polygonal shape (for example, a shape obtained by rounding the corners of a regular hexagon), and refrigerant or refrigerating machine oil can be easily passed through the outer periphery of the stator 6. There is something.
The stator 6 is obtained by punching an electromagnetic steel sheet into a shape shown in FIG. 7 to obtain a core sheet 6a, and laminating a large number of the core sheets 6a.
[0008]
As for the other parts of the stator 6, teeth 7 and slots 8 are formed in the same manner as the stator 1 shown in FIG. 6, but the shapes of the ends of the teeth 7 are different.
As shown in FIG. 8, the inner diameter side of the end portion and the outer diameter side of the slot 8 are linear and substantially parallel, and the tip depth a of the end portion is the tip of the end portion of the tooth 2 shown in FIG. It is deeper than the depth of.
[0009]
Therefore, when concentrated winding is applied to the teeth 7, the number of windings can be increased, and furthermore, since the windings are suppressed at the tooth ends, the windings protrude from the inner diameter side of the stator 6. Togana rather, the distance between the winding and the rotor 4 is maintained within prescribed.
[0010]
[Problems to be solved by the invention]
However, in the permanent magnet motor, the motor cost increases when the synthetic resin is used for the slot groove insulation, and when the depth a of the tip of the tooth end portion is increased, the adjacent teeth 2, 7 There is a drawback that the leakage magnetic flux between the end portions (primary leakage magnetic flux) increases and the motor efficiency is lowered.
[0011]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a permanent magnet electric motor capable of reducing the cost of the motor and improving the efficiency of the motor by reducing the primary leakage magnetic flux. There is to do.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention includes a rotor that forms a magnetic field using a permanent magnet, and a stator that is positioned outside the rotor and generates a rotating magnetic field. together comprise a laminated core sheets, forms the shape of the groove of a predetermined number of slots in the core sheet, in the permanent magnet motor formed by subjecting the windings on each tooth between the slots, both axial ends of the stator The plurality of core sheets are used as the first and second core parts, and a plurality of core sheets between the first and second core parts are used as the third core parts. only core portion, the tooth ends while the depth of the chip, said for the third core sheet constituting the core portion, wherein the depth of the chip of the teeth end of its first and second Less than the depth of the tip of the tooth end portion of the core sheet constituting the core portion of the core Said first through groove of the third core portion of the slot insulated with an insulating film of cuffs is characterized through the groove it has to apply the winding to the each tooth.
[0013]
In the present invention, the outer diameter side of the groove before Symbol first to third core portion of the slot and a shape along the outer periphery of the core sheet, before SL is preferably subjected to winding in concentrated winding on each tooth.
[0014]
Further, the third core portion and tip of the depth of the tooth end portion of the core sheet and 1mm or less, or less than twice the thickness of the core sheet constituting the, before Symbol insulating film, PET (polyethylene terephthalate) It is preferable to use a film, PEN (polyethylene naphthalate) or aromatic polyamide paper.
[0015]
The width of the yoke of the first to third core portions may be constant, and the width of the teeth may be 1 to 2 times the width of the yoke.
The teeth are provided at the center of each side of the outer shape of the first to third core portions, the teeth are perpendicular to the yokes of the first to third core portions, and the slots are formed on the rounded corners. The center of the groove should be arranged.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. In the figure, the same parts as those in FIGS. 6 and 7 and corresponding parts are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 is a combination of FIG. 2 and FIG. 3 and shows a cross section taken along the line A-AA and a cross section taken along the line B-BB.
[0017]
In FIG. 1, a stator 10 of this inner rotor type permanent magnet motor is formed by laminating core sheets having a substantially outer periphery, and several (for example, 4, 5) core sheets are provided on both ends thereof. Between the first and second core portions 11 and 12 made of 6a and the first and second core portions 11 and 12 (the number of core sheets 13a constituting the stator 10; for example, 100) The third and third core parts 13 and 12 are combined with each other, and the first and second core parts 11 and 12 are configured by the core sheet 6a having the shape shown in FIG. Is constituted by a core sheet 13a having the shape shown in FIG.
[0018]
As shown in FIG. 2, the 1st and 2nd core parts 11 and 12 are comprised by the core sheet 6a of the shape similar to FIG. 7 shown in the prior art example.
As already described in the conventional example, the first and second core portions 11 and 12 are formed by stacking the core sheets 6a having a six-slot structure with a substantially hexagonal outer periphery (shape with rounded corners). Note that regular hexagons are rounded along the same circle.
[0019]
Specifically, the substantially hexagonal side central portions of the core sheet 6a are extended to the core center to form teeth 7, so that the teeth 7 are formed at right angles to the yoke portion, and slots 8 are formed on each corner side. And the center of the slot 8 is defined as each corner.
In addition, the tip depth a of the end of the tooth 7 is made somewhat deeper (deeper than the tip depth b of the tooth end of the third core portion 13 to be described later), and the size of the groove opening is 3 mm or less. The length of the circumferential chord of the non-linear portion where the inside of the yoke portion intersects is 4 mm, which is 1 to 3 times the dimension of the groove opening.
[0020]
As shown in FIG. 3 and FIG. 4, the third core portion 13 has a regular hexagonal shape (rounded corner shape) and six slots, like the first and second core portions 11 and 12. The core sheet 13 a having 14 is laminated, but the end shape of the teeth 15 is different from the teeth 7 of the first and second core portions 11 and 12.
The tip depth b of the end portion (tooth end) of the tooth 15 is made shallower than the tip depth a shown in FIG. 8 to reduce the primary leakage magnetic flux, and the tip depth b of the tip of the tooth 15 is made shallower. As a result, the depth c of the mouse at the end of the tooth is deeper (the end of the end is raised).
[0021]
Specifically, for example, the depth b of the tip of the tooth end is preferably 1 mm or less or twice or less the thickness of the core sheet 13a .
[0022]
The widths of the yoke portions of the first to third core portions 11, 12, and 13 are substantially constant, and the yoke width corresponding to at least the side of the regular hexagon is a constant value k.
The width (tooth width) h of the teeth 7 of the first and second core portions 11 and 12 and the teeth 15 of the third core portion 13 is set to 1 to 2 times the yoke width k. Thereby, the balance of the magnetic flux density of the yoke portion becomes good, and as a result, the motor efficiency is improved.
[0023]
When concentrated winding of the stator 10 having the above configuration is performed, first, the third core portion 13 is sandwiched between the first core portion 11 and the second core portion 12 as shown in FIGS. Insulation is applied to the grooves of the slots 8 and 14 of the stator 10.
In this groove insulating method, an insulating film (PET film) is used to form a slot liner with cuffs (with folding back), and the slots 8 and 14 are mounted. Other preferable insulating films include PEN films and aromatic polyamide paper.
[0024]
Then, concentrated winding is directly applied to the teeth 7 and 15 by the winding machine through the slots 8 and 14 in which the insulating film 16 is mounted to form a winding (see a two-dot chain line in FIG. 5). In this case, since the inner diameter side and the outer diameter side of the grooves of the slots 8 and 14 are linear and parallel, the number of windings can be increased. Further, since the depth a of the tip end of the tooth 7 of the first and second core portions 11 and 12 is deep, winding without protruding on the inner diameter side (the rotor 4 side), and the winding The distance from the rotor 4 is maintained at a specified value.
[0025]
Thus, by using the insulating film 16 of the PET film, the cost can be reduced, and the chip depth b of the tooth end portion of the third core portion 13 is shallow, so that the adjacent teeth 15 Leakage magnetic flux (primary leakage magnetic flux) between the end portions can be reduced.
[0026]
Further, since the outer shape of the stator 10 is substantially a regular hexagon, the passage area of refrigerant (gas) and refrigeration oil can be expanded when the electric motor is applied to a compressor. A compressor can be obtained. Therefore, by adopting this compressor, it contributes also to the performance improvement of an air conditioner or an electric refrigerator.
[0027]
In the above-described embodiment, the case where the stator 10 has 6 slots has been described. However, the present invention can be applied to a stator having a different number of slots, and is particularly preferably applied to a stator having a small number of slots.
In the above embodiment, the case where the outer shape of the stator 10 is substantially a regular hexagon has been described. However, the present invention can also be applied to stators having different polygons, particularly when applied to a stator having a small number of corners. preferable.
[0028]
【The invention's effect】
According to the present invention described above, the following effects can be obtained. The stator of the permanent magnet motor of the present invention, a plurality of core sheets in the axial direction across the first and second core portions, a large number of core sheet between the first and second core portions the becomes a third core portion, only the first and second core portions, as well as the depth of the chip of the tooth ends, for the core sheet constituting the third core portion, the tooth end of its The depth of the chip is made shallower than the depth of the chip at the tooth end portion of the core sheet constituting the first and second core portions, and the slot grooves of the first to third core portions are cuffed with an insulating film. Insulating the wire and winding the teeth on each tooth through the groove makes it possible to use an inexpensive PET film, PEN film, or aromatic polyamide paper for the insulation film, realizing low motor costs. can do. Further, the leakage magnetic flux (primary leakage magnetic flux) between the tooth end portions of the core sheet of the third core portion that occupies the majority of the stators is reduced, and the motor efficiency can be improved.
[0029]
Furthermore, since the outer shape of the stator is substantially a regular hexagon and the groove of the slot is linear and parallel on the outer diameter side and the inner diameter side, not only can the number of windings of each tooth be increased, The winding of each tooth can be reliably held by the tooth end portions of the core sheet of the first and second core portions, and the distance between the winding and the rotor can be kept within a specified value.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view for explaining a permanent magnet motor according to an embodiment of the present invention.
2 is a schematic plan view for explaining first and second core portions constituting the stator of the permanent magnet motor shown in FIG. 1; FIG.
FIG. 3 is a schematic plan view for explaining a third core portion constituting the stator of the permanent magnet motor shown in FIG. 1;
4 is a schematic plan view for explaining a part of a third core portion shown in FIG. 3; FIG.
FIG. 5 is a schematic plan view for explaining a permanent magnet motor of the present invention.
FIG. 6 is a schematic plan view for explaining a conventional permanent magnet motor.
FIG. 7 is a schematic plan view for explaining a conventional permanent magnet motor.
FIG. 8 is a schematic plan view for explaining a part of the stator of the permanent magnet motor shown in FIG. 7;
6a Core sheet (of the first and second core parts 11 and 12)
7 teeth (of the first and second core parts 11, 12)
8 slots (for the first and second core parts 11 and 12)
10 Stator 11 First core portion 12 Second core portion 13 Third core portion 13a Core sheet (of the third core portion)
14 slots (3rd core part)
15 Teeth 16 Insulating film (PET film)
a Chip depth (of first and second core parts)
b Chip depth (3rd core part)
c Mouse depth (in the third core)
h tooth width i tooth end width k yoke width

Claims (5)

A rotor that forms a magnetic field using a permanent magnet, and a stator that is positioned outside the rotor and generates a rotating magnetic field, and is constituted by a core sheet in which a large number of the stators are stacked, and the core sheet in the form the form of the grooves of a predetermined number of slots, the permanent magnet motor formed by subjecting the windings on each tooth between the slots,
A plurality of core sheets in the axial direction both ends of the stator and the first and second core portions, becomes a large number of core sheets between the first and second core portions as a third core portion , only the first and second core portions, as well as the depth of the chip of the tooth end portions, wherein the third core sheet constituting the core portion, the chip of the tooth edge of its depth The depth of the chip at the tooth end portion of the core sheet constituting the first and second core portions is made shallower, and the slot grooves of the first to third core portions are insulated with an insulating film with cuffs. , permanent magnet motor, characterized in that it has to apply the winding to the each tooth through the groove. The outer diameter of the groove of the previous SL first to third core portion of the slot and a shape along the outer periphery of the core sheet, in claim 1 which before Symbol made so as to apply the winding at concentrated winding on each tooth The permanent magnet motor described .   The permanent magnet motor according to claim 1, wherein a PET film, a PEN film, or an aromatic polyamide paper is used as the insulating film. The permanent magnet motor for a compressor according to any one of claims 1 to 3, wherein an outer periphery of the stator has a polygonal shape . Compressor according provided with the teeth in the middle of each side of the outline of the first to third core portion, in claim 4 the teeth formed by the yoke and the perpendicular direction of the first to third core portion use permanent magnet motor.

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