JP2002084690A - Electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an efficient magnet electric motor that increases demagnetization yield strength, and can be speedily rotated. SOLUTION: In the shape of a permanent magnet for forming a field, the outer-periphery surface of the permanent magnet and that of a rotor should be set at equal distances, at the same time, thickness at a middle section in the radius direction of the rotor should be set thicker than that of a periphery section and at the same time should be set thinner that that where a shape at the center side of the rotor of the permanent magnet is set to a plane, and, roundness with specific radius should be provided at en end section in the circumferential direction of the rotor in the outer-periphery surface of the permanent magnet. Also, a plurality of slits should be provided at either of the core section between the mutually adjacent permanent magnets or an outer-periphery core section outside each permanent magnet of the rotor. Additionally, a permeable sticking agent should be filled into the gap between a hole for the permanent magnet punched at the core section of the rotor and the permanent magnet, and the core section of the rotor should be stuck to the permanent magnet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet motor capable of obtaining high efficiency during high-speed rotation, and more particularly to a structure of a rotor of a magnet motor used for a hermetic compressor.

[0002]

2. Description of the Related Art In a conventional rotor of a magnet motor, permanent magnets forming magnetic poles are arranged as shown in FIG. That is, the permanent magnet 13 is arranged as shown in FIG. 6, the portion 13a is located closer to the outer periphery of the rotor 11, the portion 13b is flat, and the radially intermediate portion of the rotor 11 is located closer to the outer periphery of the rotor 11 than the peripheral portion. It was a structure in which the distance from was large. By adopting such a structure, the inductance between the stator 13b and the stator (not shown) is larger than the inductance of the portion 13a, and a method of positively utilizing the reluctance torque due to the difference between the inductances as the rotational torque. Was used.

[0003] Fig. 7 shows a magnet motor of a hermetic compressor according to the prior art, and Fig. 7 (a) shows a magnet motor of Fig. 7 (b).
FIG. 7B is a longitudinal sectional view taken along the line A, and FIG.
FIG. 3 is a cross-sectional view taken along line BB of FIG. The magnet motor 70 is
It comprises a stator 61 and a rotor 62. The stator 61 is configured by winding a winding 65 on a cylindrical iron core 63 formed by laminating a large number of thin magnetic steel sheets, through a plurality of slots 64 provided at predetermined intervals in the circumferential direction. I have.

The rotor 62 has a cylindrical shape, and is formed by laminating a number of thin magnetic steel plates. The rotor 62 has a magnetic pole directed circumferentially at a predetermined interval in the circumferential direction of the iron core 66, and And a plurality of (four in this figure) permanent magnets 67 buried as close to the outer surface of the rotor 62 as manufacturing permits. Further, a rotation shaft 68 is fixed through the center of the iron core 66. An upper end plate 7 is provided at the upper end of the rotor 62.
1, a lower end plate 72 is provided at a lower end, and a core 66, a permanent magnet 67, an upper end plate 71, and a lower end plate 72 are fixed by rivets 73.

[0005]

However, the magnet motor shown in FIG. 6 has a problem that the input voltage is insufficient due to the voltage drop of the inductance, and high-speed operation cannot be performed.

Further, in the rotor having the structure shown in FIG. 7, the permanent magnets are merely buried and arranged in the permanent magnet holes formed in the iron core in which a large number of thin magnetic steel sheets are laminated. There is a problem in that the inductance of the outer peripheral core of the rotor outside the permanent magnet increases, the magnetic flux flowing through the core increases, and the loss increases.

Further, a gap is formed between the permanent magnet hole of the iron core and the permanent magnet buried in the hole, and the magnetic resistance of the gap is large, so that the formation of a magnetic path is hindered. there were.

The present invention has been made under such a background. The permanent magnet of the rotor has the same inductance in the rotating direction, and the thickness of the intermediate portion in the radial direction is equal to that of the peripheral portion. It is an object of the present invention to provide a high-efficiency magnet motor capable of increasing the demagnetization proof strength by making it thicker than the thickness and enabling high-speed rotation.

In addition, a plurality of slits are formed in one or both of the outer peripheral core portion of the rotor outside each permanent magnet and the core portion between each permanent magnet and the adjacent permanent magnet in a direction converging outside the rotor. It is an object of the present invention to provide a magnet motor capable of improving efficiency by increasing the magnetic flux density from the rotor and improving efficiency by reducing the iron loss of the rotor.

It is another object of the present invention to provide a high-efficiency magnet motor in which the magnetic resistance is reduced by filling a gap between the permanent magnet hole of the iron core and the permanent magnet with a magnetically permeable fixing agent. It is another object of the present invention to provide a magnet electric motor that improves the rigidity of the rotor by using the above-mentioned adhesive and eliminates the need for a caulking clamp for fixing between the iron core and the permanent magnet.

[0011]

According to a first aspect of the present invention, there is provided a rotor for forming a magnetic field by a permanent magnet embedded in a laminated steel sheet serving as a magnetic path, and an electric motor provided in a slot of the laminated steel sheet serving as a magnetic path. A stator having an armature winding disposed thereon to form an armature, wherein the motor is configured to energize the armature winding to generate a rotational torque between the armature winding and the rotor. The outer peripheral surface of the permanent magnet and the outer peripheral surface of the rotor are equidistant from each other, and have a shape in which the thickness of a radially intermediate portion of the rotor is greater than the thickness of the peripheral portion. To provide an electric motor.

According to the present invention, the demagnetization resistance of the permanent magnet is large, and the inductance between the permanent magnet of the rotor and the stator is reduced, so that an excessive input is not required, and high efficiency and suitable for high-speed rotation. Motor.

According to a second aspect of the present invention, in the electric motor according to the first aspect, a circumferential end of the rotor is provided with a predetermined radius on an outer peripheral surface of the permanent magnet. Features.

According to the present invention, it is easy to punch a laminated steel plate of a rotor for embedding a permanent magnet, and to manufacture a motor having high dimensional accuracy even if the distance between the outer periphery of the permanent magnet and the outer periphery of the laminated steel plate is short. can do.

According to a third aspect of the present invention, in the electric motor according to the first or second aspect, the thickness of the intermediate portion of the permanent magnet is such that the shape of the permanent magnet on the center side of the rotor is flat. It is characterized in that it is thinner than the thickness when it becomes.

According to the present invention, it is possible to provide an electric motor in which the shape of the permanent magnet on the output shaft side is prevented from expanding beyond a plane, and the demagnetization resistance can be increased without increasing the shape of the permanent magnet more than necessary. .

According to a fourth aspect of the present invention, a plurality of permanent magnets are buried near the outer peripheral surface of the iron core formed of laminated magnetic steel sheets at predetermined intervals in the circumferential direction so that the magnetic poles are directed in the circumferential direction. In a magnet motor having a rotor having a fixed shaft penetrated and fixed at the center of the iron core, an iron core between the permanent magnets adjacent to each other of the rotor or an outer peripheral iron core outside each permanent magnet of the rotor. And a plurality of slits are provided in any one of the above.

According to a fifth aspect of the present invention, in the magnet motor of the fourth aspect, an iron core portion between the permanent magnets adjacent to each other of the rotor and an outer peripheral iron core portion outside each permanent magnet of the rotor. Are provided with a plurality of slits.

According to the fourth or fifth aspect of the present invention, a plurality of slits are provided in one or both of the core portion between the permanent magnets adjacent to each other of the rotor and the outer peripheral core portion outside each permanent magnet of the rotor. Is provided, efficiency can be improved by increasing the magnetic flux density from the rotor, and efficiency can be improved by reducing iron loss of the rotor.

According to a sixth aspect of the present invention, in the magnet motor of the fourth or fifth aspect, the plurality of slits provided in the core portion between the permanent magnets adjacent to each other of the rotor are formed by the plurality of slits. It is characterized in that adjacent permanent magnets are connected by a straight line or an arc.

According to a seventh aspect of the present invention, in the magnet motor according to the fourth or fifth aspect, the plurality of slits provided in an outer peripheral iron core portion outside each permanent magnet of the rotor are provided. It is characterized by a plurality of slits having a shape converging on the outside.

According to the sixth or seventh aspect of the present invention, the slit having the above-described shape can improve the efficiency by increasing the magnetic flux density from the rotor and improve the efficiency by reducing the iron loss of the rotor.

[0023] The invention according to claim 8 is the invention according to claims 1 to 7.
In the magnet motor according to any one of the above, a gap between the permanent magnet hole and the permanent magnet perforated in the core of the rotor is filled with a magnetically permeable fixing material, and the core of the rotor and the core are filled. It is characterized by being fixed to a permanent magnet.

According to the eighth aspect of the present invention, the magnetic resistance is reduced by filling a gap between the permanent magnet hole of the iron core and the permanent magnet with a magnetically permeable fixing agent, thereby providing a highly efficient magnet motor. be able to. Further, the rigidity of the rotor is improved by using the above-mentioned fixing agent, and it becomes possible to omit a caulking clamp for fixing between the iron core and the permanent magnet.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a structure of a rotor of an electric motor according to one embodiment of the present invention. In this figure, reference numeral 1 denotes a rotor constituted by laminated steel sheets, which is connected to an output shaft 2 and has a number of permanent magnets 3 embedded according to the number of magnetic poles to form a field.

The feature of the present invention lies in the shape of the permanent magnet 3. As shown in the figure, the shape of the outer peripheral side of the permanent magnet 3 is set at an equal distance Sa from the outer periphery of the rotor 1, Mm, the thickness of the peripheral portion is Ms, and the distance from the outer peripheral surface of the laminated steel plate of the rotor 1 to the outer peripheral surface of the permanent magnet 3 is S.
a, the distance between the mutually facing surfaces of the adjacent permanent magnets is Sb, and the radius of the rotor 1 is r, Ms <Mm <(1− (0.5 × √2)) × (r−Sa )
+ (0.5 × √2) × (Ms−Sb / 2).

This is because the shape of the outer periphery of the permanent magnet 3 is set at an equal distance Sa from the outer periphery of the rotor 1, the value of Mm of the permanent magnet 3 is larger than Ms, and The case where the surface is a flat surface as shown in FIG. 2 is the maximum value, which indicates that the surface does not normally swell. By adopting such a shape, the inductance becomes equal in the rotation direction of the rotor, and the thickness of the middle part in the radial direction is made larger than the thickness of the peripheral part, thereby increasing the demagnetization resistance and enabling high-speed rotation. Thus, it is possible to provide a highly efficient electric motor.

As shown in FIG. 3, a predetermined radius r0 is provided on the outer circumferential surface of the permanent magnet 3 at the circumferential end of the rotor.
By making the roundness, it is easy to punch the laminated steel plate of the rotor for embedding the permanent magnet, and to produce a motor with high dimensional accuracy even if the distance between the outer periphery of the permanent magnet and the outer periphery of the laminated steel plate is short. Can be.

Next, another embodiment of the present invention will be described with reference to FIG. In this figure, the rotor 102
In the circumferential direction of the iron core 106, a permanent magnet hole 106a is opened at a predetermined interval, and a permanent magnet 107 is embedded. The outer peripheral iron core 114 of the rotor 102 outside each of the permanent magnets 107 includes the rotor 102 and the respective permanent magnets 1.
A plurality of slits 116 are formed so as to converge toward a point P outside the rotor 102 on a line connecting the centers of the circles 07. In the iron core 115 between each permanent magnet 107 and the adjacent permanent magnet 107, a plurality of straight or arc-shaped slits 117 connecting the adjacent permanent magnets are formed.

Referring to FIG. 4, iron core 106 of rotor 102
, The outer core portion 1 of the rotor 2 outside each permanent magnet 107
14 and a plurality of slits 116 and 117 are formed in the iron core portion 115 between each permanent magnet 107 and the adjacent permanent magnet 107 so as to converge to a point P outside the rotor 102. The flow of magnetic flux generated from 107 is blocked by these slits and
6 is controlled and converged in the direction of the point P. Thus, efficiency can be improved by increasing the magnetic flux density from the rotor 102, and efficiency can be improved by reducing iron loss of the rotor 102.

In the above-described embodiments shown in FIGS. 1 to 4, the permanent magnet and the hole for the permanent magnet in the iron core are not clearly shown. As shown in FIG.
06 are not in close contact with each other, and there is a gap 120 in the permanent magnet hole 106a. The gap 120 has a large magnetic resistance and hinders formation of a magnetic path of the generated magnetic field.

By filling the gap 120 with a magnetically permeable fixing agent, the magnetic resistance of this portion is reduced, the motor efficiency is improved, the rigidity of the rotor 102 is improved, and the generated magnetic field is stabilized. be able to. Also, rotor 1
02 can be expected to reduce the cost by improving the rigidity of O.02 and eliminating the caulking clamp for fixing the permanent magnet 107 and the iron core 106.

The operation of one embodiment of the present invention has been described above in detail with reference to the drawings. However, the present invention is not limited to this embodiment, and a design change or the like may be made without departing from the gist of the present invention. The present invention is also included in the present invention. For example, the plurality of slits provided in other embodiments need not necessarily converge to one point P outside the rotor, but may be in a direction in which they converge.

[0034]

According to the present invention, as described above, the outer peripheral surface of the permanent magnet and the outer peripheral surface of the rotor are equidistant, and the thickness of the intermediate portion in the radial direction of rotation is reduced by the peripheral portion. The thickness of the permanent magnet is greater than that of the rotor, so the demagnetization resistance of the permanent magnet is large, the inductance between the permanent magnet of the rotor and the stator is small, and it does not require excessive input, enabling high efficiency and high speed rotation. The effect that a suitable electric motor can be obtained is obtained.

In addition, a plurality of slits are formed in one or both of the outer peripheral iron core portion of the rotor outside each permanent magnet and the iron core portion between each permanent magnet and the adjacent permanent magnet in a direction converging outside the rotor. The effect of improving the efficiency by increasing the magnetic flux density from the rotor and improving the efficiency by reducing the iron loss of the rotor can be obtained.

By filling the gap between the permanent magnet and the hole for the permanent magnet with a magnetically permeable fixing agent, the magnetic resistance in this portion is reduced, the motor efficiency is improved, and the rigidity of the rotor is improved. The effect that the generated magnetic field can be stabilized can be obtained. Further, a caulking clamp for fixing the permanent magnet and the iron core can be omitted, and an effect that cost reduction can be expected can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of a rotor of a magnet motor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining the maximum thickness of the permanent magnet shown in FIG. 1 at the center in the rotation direction.

FIG. 3 is a cross-sectional view for explaining chamfering of an outer peripheral surface of the permanent magnet of FIG. 1;

FIG. 4 is a cross-sectional view showing a structure of a rotor of a magnet motor according to another embodiment of the present invention.

FIG. 5 is a diagram showing a gap between a permanent magnet hole of a core and a permanent magnet.

FIG. 6 is a cross-sectional view showing a structure of a rotor of a magnet motor according to a conventional technique.

7 (a) and 7 (b) show a magnet motor of a hermetic compressor according to a conventional technique, FIG. 7 (a) is a longitudinal sectional view taken along line AA of FIG. 7 (b), and FIG. FIG. 3A is a cross-sectional view along the line BB.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotor 2 ... Output shaft 3 ... Permanent magnet 11 ... Rotor 12 ... Output shaft 13 ... Permanent magnet 102 ... Rotor 106 ... Iron core 106a ... Permanent magnet hole 107 ... Permanent magnet 114 ... Peripheral iron core 115 ... Permanent Iron core between magnet and adjacent permanent magnet 116 ... slit 117 ... slit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuo Kanie 1 Nagoya Laboratory, Iwazuka-cho, Nakamura-ku, Nagoya City, Aichi Prefecture Inside of Nagoya Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Akihiro Hoshino No. 1 Takamichi Industrial Equipment Division, Mitsubishi Heavy Industries, Ltd. (72) Inventor Shinichi Isobe No. 1, Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi Prefecture Inside Industrial Equipment Division, Mitsubishi Heavy Industries, Ltd. (1) Nakano Engineering Co., Ltd. (72) Inventor Akihiro Noguchi 60, Iwatsuka-cho, Iwatsuka-cho, Nagoya-shi, Aichi Prefecture F term (reference) 5H002 AA03 AA05 AB07 AC06 AE08 5H621 AA03 GA01 GA04 GB10 HH01 HH08 JK02 JK05 JK15 5H622 AA03 CA02 CA05 CA13 CB04 CB05 CB06 PP10 PP11 PP19 QB02

Claims (8)

[Claims] 1. A rotor that forms a field with a permanent magnet embedded in a laminated steel sheet that forms a magnetic path, and an armature winding is disposed in a slot of the laminated steel sheet that forms a magnetic path to form an armature. An electric motor having a stator and generating a rotational torque between the armature winding and the rotor by energizing the armature winding, wherein the permanent magnet has an outer peripheral surface of the permanent magnet and an outer periphery of the rotor. An electric motor characterized in that a surface is equidistant and a thickness of an intermediate portion in a radial direction of the rotor is thicker than a thickness of a peripheral portion. 2. The electric motor according to claim 1, wherein an outer circumferential surface of the permanent magnet has a predetermined radius at an end in a circumferential direction of the rotor. 3. The method according to claim 1, wherein a thickness of the intermediate portion of the permanent magnet is smaller than a thickness when the shape of the permanent magnet on the center side of the rotor is a flat surface. An electric motor as described. 4. A plurality of permanent magnets are buried near the outer peripheral surface at predetermined intervals in the circumferential direction of an iron core formed of laminated magnetic steel sheets so that their magnetic poles are directed in the circumferential direction, and are fixed to the center of the iron core. A magnet motor having a rotor having a shaft fixed therethrough, wherein a plurality of slits are provided in either an iron core portion between the permanent magnets adjacent to each other of the rotor or an outer peripheral iron core portion outside each permanent magnet of the rotor. A magnet motor comprising: 5. A plurality of axial slits are provided both in an iron core between adjacent permanent magnets of the rotor and in an outer peripheral iron core outside each permanent magnet of the rotor. Item 6. The magnet motor according to item 4. 6. The plurality of slits provided in an iron core between adjacent permanent magnets of the rotor have a shape that connects the adjacent permanent magnets with a straight line or a circular arc. The magnet motor according to claim 4 or 5, wherein 7. The plurality of slits provided in an outer peripheral iron core portion outside each permanent magnet of the rotor are a plurality of slits having a shape converging outside the rotor. A magnet motor according to claim 4. 8. A gap between the permanent magnet hole and the permanent magnet formed in the core of the rotor is filled with a magnetically permeable fixing material to fix the core of the rotor to the permanent magnet. The magnet motor according to any one of claims 1 to 7, wherein: