JP2001268832A - Permanent magnet rotor and electric compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet rotor which prevents scattering of permanent magnet and wear of members due to the scraping without lowering the characteristics of a motor. SOLUTION: A permanent magnet rotor 21 comprises a cylindrical rotor iron core 1 provided at the external circumferential side of a stator iron core 25, and a plurality of permanent magnets 23 that are fixed in the internal circumferential side of this rotor iron core 25 opposing to the stator iron core 25 in the circumferential direction. A gap between the permanent magnet 23 and stator iron core 25 is set small at the center 27 of the magnetic poles of the permanent magnet 23 and is set large as it goes to the area 29 between the poles for the adjacent permanent magnet 23, and the internal circumferential surface of the permanent magnet rotor 21 is covered with a cylindrical member 31 made of resin that becomes thinner at the center 27 of the magnetic poles of the permanent magnet 23 and becomes thicker at the area between magnetic poles 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet rotor which is arranged on the outer peripheral side of a stator and can prevent the permanent magnet from scattering.
The present invention also relates to an outer rotor type electric compressor having an improved stator mounting structure.

[0002]

2. Description of the Related Art
In the permanent magnet rotor arranged on the outer peripheral side of the stator,
FIGS. 16 and 17 show a structure for attaching a permanent magnet to a yoke.

A permanent magnet rotor 1 shown in FIG. 16 has a plurality of permanent magnets 3 attached to the inner peripheral surface of a cup-shaped yoke 2 using an adhesive. In the permanent magnet rotor 4 shown in FIG. 2, a plurality of permanent magnets 3 are provided inside the cup-shaped yoke 2.
Are integrally formed with the mold 5.

[0006] However, the fixing with the adhesive shown in FIG. 16 has a problem that when exposed to a high-temperature environment, the adhesive strength is reduced and the magnet may fall off. In addition, when used in a hermetic compressor, there is a problem that the adhesive may be deteriorated by being exposed to a refrigerant or a lubricating oil, or the components of the adhesive may be melted into a refrigeration cycle and adversely affected. Further, it is difficult to cover the permanent magnet with the adhesive, and the permanent magnet cannot be prevented from being scattered due to cracking or chipping of the permanent magnet.

In the case of integrally molding using the resin shown in FIG. 17, extra steps are required to set the yoke portion and the permanent magnet in the mold. Pre-heating requires more man-hours.
For this reason, there has been a problem that the cost is increased. Further, when setting the permanent magnet in the mold, a part of the permanent magnet needs to be brought into contact with the mold so that the permanent magnet does not move. For this reason, as shown in FIG. 17, the concave portion 6 from which the permanent magnet is exposed to the outside is formed, and the permanent magnet cannot be completely covered with the resin. Therefore, there is a problem that scattering of the permanent magnet cannot be completely prevented.
Furthermore, when exposed to an environment in which the temperature changes sharply between low and high temperatures for a long period of time, the resin, the yoke, and the permanent magnet may peel off due to the difference in their expansion coefficients, which may cause decomposition. Was.

The present invention has been made in view of the above circumstances, and has as its object to provide a permanent magnet rotor which can prevent scattering of a permanent magnet and wear of a member due to rubbing without deteriorating the characteristics of a motor. And

[0007] On the other hand, a conventional external rotary rotor type electric compressor is disclosed in, for example, Japanese Utility Model No. 3063451. This external rotation rotor type electric compressor 11 is shown in FIG. 18, in which a cup-shaped rotor 13 is mounted on a shaft 17 of a compression mechanism 12, and a stator mounting member 15 is mounted on a stator 14 above. It is attached to the compressor hermetic container 16 through the intermediary of the compressor.

However, such an external rotary rotor type electric compressor 11 requires an extra member for mounting the stator 14, and the stator 14 is mounted on the shaft 17 because the stator 14 is mounted on the closed vessel 16. Rotor 1
There is a problem that it is difficult to make the air gap between the first and third steel plates uniform, and assembly is troublesome, such as assembling with a plate gauge interposed or adjusting the air gap.

In order to counter the gap suction force of the motor, the stator mounting member 15 needs to have high strength.
It becomes heavier by increasing the rigidity. Furthermore, rotor 1
3. Since the stator 14 and the stator mounting member 15 are arranged so as to be stacked in series, a large space is required in the height direction, and there is a problem that the overall height of the compressor is increased.

The present invention has been made in view of the above circumstances, and has as its object to provide a compact external rotation rotor type electric compressor which is easy to assemble.

[0011]

A first feature of the present invention is as follows.
A cylindrical rotor core provided on the outer peripheral side of the stator, and a plurality of permanent magnets fixed to the inner peripheral side of the rotor core and arranged in a circumferential direction facing the stator. In the permanent magnet rotor having, the air gap between the permanent magnet and the stator is reduced at the center of the magnetic poles of the permanent magnet, and is increased toward the gap between the adjacent permanent magnets. In addition, the inner peripheral surface of the permanent magnet rotor is covered with a resin-made cylindrical member whose center portion of the magnetic poles of the permanent magnet is thinner and thicker as it goes to the gap.

[0012] A second feature of the present invention is that in the gap,
A projection is provided that protrudes from the inner peripheral surface of the rotor core, and the permanent magnet is fixed by the projection.

A third feature of the present invention is that the cylindrical rotor core is provided with a bottom wall at one axial end thereof for transmitting the rotation of the rotary core to a rotary shaft. Is
It is a laminated body including a plurality of punched plates, and the plurality of punched plates are fixed to the bottom wall using bolts or rivets.

A fourth feature of the present invention is that an annular end plate that covers an end of the permanent magnet is provided on an end surface of the cylindrical rotor core opposite to the bottom wall. That is.

A fifth feature of the present invention is that an end of the cylindrical member on the side of the bottom wall is in contact with the bottom wall.

A sixth feature of the present invention is that a flange-like flange extending radially outward from this end is provided at an end of the cylindrical member opposite to the bottom wall, This Tsuba
That is, it is sandwiched and fixed between the annular end plate and the permanent magnet.

A seventh feature of the present invention is that it has a bearing boss protruding outward and a rotating shaft penetrating the bearing boss and protruding outward from the bearing boss. A compression mechanism, a cylindrical stator fixed to the outer periphery of the bearing boss of the compression mechanism, and a tip protruding from the bearing boss of the rotating shaft, An umbrella-shaped rotor extending radially outward of the rotating shaft, and then extending in a cylindrical shape in the direction of the compression mechanism along the outer peripheral surface of the annular stator, wherein the stator and the umbrella-shaped rotor are provided. An electric motor including a rotor drives the compressor by rotating the rotating shaft.

An eighth feature of the present invention is that a cylindrical support is fixed to the inner peripheral surface of the stator, and the inner peripheral surface of the cylindrical support is fixed to the bearing boss.

A ninth feature of the present invention is that the umbrella-shaped rotor has a viewing hole through which a gap between the umbrella-shaped rotor and the stator can be observed.

A tenth feature of the present invention is that the umbrella type rotor of the electric compressor is a permanent magnet rotor.

[0021]

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

FIG. 1 shows a cross section perpendicular to the axis of a permanent magnet rotor 21 according to a first embodiment of the present invention. In this figure, four permanent magnets 23 are arranged on the inner periphery of the rotor core 1 with a small gap in the circumferential direction. The outer peripheral surface of these permanent magnets 23 is formed as a part of a cylindrical surface along the inner peripheral surface of the rotor core 1. Also,
The inner peripheral surface of the permanent magnet 23 has a central portion 27 in the circumferential direction.
Are formed so as to protrude inward in the radial direction and become thicker, while being formed so that both ends in the circumferential direction recede outward in the radial direction and become thinner. Therefore, the gap between the inner peripheral surface of the permanent magnet 23 and the stator core 25 having the cylindrical outer peripheral surface is formed by the central portion 27 of the magnetic pole of the permanent magnetic pole 23.
Is small, and becomes larger as it goes to the gap 29 between the magnetic poles of the permanent magnets 23 adjacent in the circumferential direction. Also,
On the inner periphery of such a permanent magnet 23, these permanent magnets 2
3 is provided with a resin-made cylindrical member 31 that covers the inner peripheral surface. The inner peripheral surface of the cylindrical member 31 is formed in a cylindrical shape so as to keep a constant distance from the outer peripheral surface of the stator core 25. The outer peripheral surface of the cylindrical member 31 has a shape along the inner peripheral surface of the four permanent magnets 23 arranged in the circumferential direction. Therefore, the cylindrical member 31 is formed so as to be thin at the central portion 27 of the magnetic pole of the permanent magnet 23 and to become thicker toward the interpole portion 29.

As described above, in the above embodiment, since the inner peripheral surface of the permanent magnet 23 is covered with the cylindrical member 31 made of resin, unlike the case where a cylindrical member made of metal is used, an eddy current is generated. The scattering of the rotating permanent magnet can be prevented without causing loss. Further, in the case of a cylindrical member made of resin, it is difficult to reduce the thickness in the molding process, and a substantial gap is increased, so that the characteristics are likely to deteriorate.
However, in this embodiment, as shown in FIG. 1, the air gap between the permanent magnet 23 and the stator core 25 is made smaller at the center portion 27 of the magnetic pole and is increased toward the gap portion 29. The resin-made cylindrical member 31 is formed such that the center part 27 of the magnetic pole is thin and becomes thicker toward the gap part 29. Therefore, the resin surroundings in molding can be improved, and the thickness of the resin at the center portion 27 of the magnetic pole, which requires a large amount of magnetic flux, can be reduced. In addition, the cogging torque can be suppressed by concentrating the magnetic flux at the center portion 27 of the magnetic pole and decreasing as it goes to the gap portion 29, thereby simultaneously improving the characteristics by suppressing useless magnetic flux. Can be.

FIG. 2 is a cross-sectional view perpendicular to the axis showing the gap 29 between the permanent magnets 23 according to the second embodiment of the present invention.
A pair of locking projections 33 projecting inward in the radial direction from the inner peripheral surface of the rotor core 1 are provided in the gap portion 29. The pair of locking projections 33 are bent in the direction in which the tips are separated from each other, and the permanent magnets 23, 23 disposed on both sides of the pair of locking projections 33 at this portion are provided.
Is to be held.

As described above, in the present embodiment, FIG.
As shown in FIG. 3, a locking projection 33 extending from the rotor core 1 is provided, and the permanent magnet 23 is fixed by the elasticity of the locking projection 33. Therefore, an extra member for fixing the permanent magnet is provided. The permanent magnet can be fixed simply and securely without requiring any man-hours. Further, since two locking projections 33 are projected and each of the locking projections comes into contact with the permanent magnet, interference between the permanent magnets can be prevented, and wear of the member due to rubbing can be avoided. Can be.

FIG. 3 shows a permanent magnet rotor 41 according to a third embodiment of the present invention. The permanent magnet rotator 41 has a bottom wall 4 having an attachment portion 45 to the shaft 43.
7. A cylindrical rotor core 49 in which a plurality of punched plates are laminated is provided on the outer periphery of the bottom wall portion 47, and is assembled in a cup shape. A plurality of punched plates of the rotor core 49 are bolted or rivets 51 to the bottom wall 4.
7 is fixed.

As described above, in the present embodiment, since the rotor core 49 is a laminate of punched plates, the locking projections 33 can be easily formed by punching.
Further, as shown in FIG. 3, since the punched laminate is attached to the bottom wall portion 47 using bolts or rivets 51, the laminate, which tends to lack rigidity, can be firmly integrated. Thus, the cup-shaped permanent magnet rotor 41 can be easily formed.

FIG. 4 shows a permanent magnet rotor 61 according to a fourth embodiment of the present invention. The permanent magnet rotor 61 is configured such that the opening end face of the rotor core 49 is formed into an annular end plate 6.
3 to cover the end surface of the permanent magnet 23. By doing so, it is possible to prevent the permanent magnet from coming out of the rotor core, and to prevent the fragments from being scattered even if the permanent magnet is damaged.

FIG. 5 shows a permanent magnet rotor 71 according to a fifth embodiment of the present invention. In this permanent magnet rotor 71, the outer periphery of the end of the resin cylindrical member 31 on the shaft 43 side is in contact with the inner periphery of the bottom wall portion 47 over substantially the entire periphery. In this permanent magnet rotor 71, the outer periphery of the end of the resin cylindrical member 31 on the shaft 43 side is brought into contact with the inner periphery of the bottom wall over almost the entire periphery, so that the opening side The entire permanent magnet can be covered together with the covering by the end plate 63, and the scattering of the pieces of the magnet can be completely prevented.

FIGS. 6 and 7 show a permanent magnet rotor 81 according to a sixth embodiment of the present invention. As shown in FIG. 6, a flange 83 is provided at the end of the cylindrical member 31 made of resin, and the flange 83 is sandwiched between the end plate 63 and the permanent magnet 23 to assemble as shown in FIG. As described above, in the permanent magnet rotor 81, as shown in FIG. 7, the flange 83 is provided at the end of the cylindrical member 31 made of resin, and the flange 83 is provided between the end plate 63 and the permanent magnet 23. Since it is sandwiched and assembled, the movement in the thrust direction of the cylindrical member 31 made of resin can be restricted, and falling off and friction can be prevented.

FIG. 8 is a longitudinal sectional view showing an external rotary rotor type electric compressor 91 according to a seventh embodiment of the present invention. The external rotation rotor type electric compressor 91 has a compressor closed container 93. A compression mechanism 95 for compressing a fluid is provided at the bottom in the compressor closed container 93. The compression mechanism 95 is provided with a rotating shaft 99 which is supported by a bearing 97. The rotating shaft 99 is connected to the compression mechanism 9
5, which is arranged to extend in the axial direction of the compressor hermetic container. The bearing 9
Numeral 7 protrudes cylindrically in the axial direction along the outer periphery of the rotating shaft as it is to form a bearing boss 101. A cylindrical stator 103 constituting a part of the electric motor is fixed to the outer periphery of the bearing boss 101 by fitting the inner periphery thereof.
On the other hand, an umbrella-shaped rotor 105 is fixed to the upper end of the rotating shaft that protrudes upward through the bearing boss 101.
The umbrella-shaped rotor 105 extends radially outward from the tip of the rotating shaft 99 and extends downward from the outer periphery of the flange 107 along the outer peripheral surface of the stator 103. The cylindrical portion 109 and the cylindrical portion 109
And a permanent magnet 111 provided on the inner peripheral surface of the rotor. And the electric motor 113 in which the umbrella-type rotor 105 rotates around the stator 103 is formed.

In such an external rotation rotor type electric compressor 91, since the stator 103 is directly fixed to the bearing boss 101 which is a part of the compression mechanism 95, an extra part for fixing is provided. No components are required. In addition, the stator 103 and the umbrella-type rotor 105 are not interposed between the closed container 93 and the rotating shaft 9.
9. Since the bearing is directly fitted via the bearing boss 101,
The centering between the stator 103 and the umbrella-shaped rotor 105 can be easily performed, and the motor gap can be easily made uniform. Further, the bearing boss 101 and the rotor mounting portion 115 can be accommodated in the coil end of the stator, and the whole can be made compact.

FIG. 9 is a longitudinal sectional view showing a main part of an external rotary rotor type electric compressor 121 according to the eighth embodiment. The outer-rotating rotor-type electric compressor 121 has a cylindrical support 123 fitted on the inner periphery of the stator 103 over the entire length of the stator 103 and the cylindrical support 123 fitted on the bearing boss 101. It is.

As described above, in the externally-rotating rotor type electric compressor 121, the cylindrical support 12
The strength of the stator core (generally, a laminated body of thin plates) can be increased by fitting 3. Therefore, the length of insertion of the bearing boss into the stator can be shortened by the improvement in the strength of the stator.

FIG. 10 is a longitudinal sectional view showing a main part of an external rotation rotor type electric compressor 131 according to a ninth embodiment. In the outer rotor type electric compressor 131, a cylindrical support 133 extending over the entire length of the stator 103 is fitted to the inner periphery of the stator 103, and a portion of the cylindrical support 133 fitted to the bearing boss 101. A large-diameter portion 135 whose inner diameter is larger than the inner diameters of the other portions is formed to be stepped, and the bearing boss 101 is fitted to the large-diameter portion 135. In this way, by providing the large-diameter portion 135 on the cylindrical support 133 and forming a step, it is possible to suppress an increase in the inner diameter of the stator.

FIG. 11 is a sectional view perpendicular to the axis of the external rotary rotor type electric compressor 141 according to the tenth embodiment, in which the sectional shape perpendicular to the axis of the compressor sealed container 143 is oblong. 8, the lead wire 145 of the stator 103 is used.
, From the lower side of the stator 103 to the upper portion of the sealed container through the vicinity of the side surface of the rotor 105, it is necessary to increase the inner diameter of the sealed container in order to secure a space through which the lead wire 145 passes. On the other hand, this externally-rotating rotor type electric compressor 141
In this case, as shown in FIG. 11, the closed container 143 is formed into an elliptical shape, so that only the diameter on the side through which the lead wire 145 passes is increased, so that the size of the closed container can be suppressed.

FIG. 12 is a sectional view taken at right angles to the axis of an external rotary rotor type electric compressor 151 according to the eleventh embodiment.
3 and the center of rotation of the compression mechanism 95 is shifted from the center of the cylindrical hermetic container 93 in the opposite direction from the side where the outlet line 145 is located. By doing so, it is possible to create a space for passing the lead wire 145, and therefore, it is possible to suppress an increase in the overall size of the sealed container as a whole.

In FIG. 12, the sealed container 93 and the rotor 1
The side with the larger gap with the compression mechanism section blade 153 is
The side is shown. As shown in FIG. 13, the compression mechanism is configured such that a roller 157 rotates on a cylinder 155, and a movable blade 153 is provided on one side. The outer diameter of the blade 153 is small to secure a blade movable range. Hard to do. Therefore, as shown in FIG. 12, it is more effective to reduce the overall size if the side where the gap between the closed vessel 93 and the rotor 105 is larger is set to the compression mechanism blade 153 side.

FIG. 14 is a longitudinal sectional view showing a main part of an external rotation rotor type electric compressor 161 according to the twelfth embodiment. The external rotation rotor type electric compressor 161 is provided with a bearing boss 16.
A concave portion 165 having a larger inner diameter is formed on the inner peripheral side of the distal end portion of No. 3 so as to be spaced from the rotating shaft 99. By doing so, the rotating shaft 99 and the bearing boss 16
The number of sliding portions with the bearing 3 is reduced, and the working of the bearing is facilitated.

FIG. 15 is a sectional view perpendicular to the axis of an external rotary rotor type electric compressor 171 according to the thirteenth embodiment. The rotor 105 of the electric motor 113 and the stator 103 are provided on the upper end surface of the umbrella type rotor 105. Is provided with a peephole 173 through which a gap between the two can be seen. By doing so, the compressed gas passing through the gap can be guided to the upper part, and the gap can be checked, so that the gap can be checked after assembly.

It should be noted that in the above-mentioned external rotary rotor type electric compressor, it is of course possible to employ the above-mentioned permanent magnet rotor as the umbrella type rotor. In this way, it is possible to prevent the permanent magnet from being scattered during rotation, to improve the circumference of the resin in molding, to reduce the resin thickness at the center of the magnetic pole, and to prevent deterioration in characteristics due to an increase in the gap. In addition, the centering of the stator and the umbrella-shaped rotor can be easily performed, and the bearing boss portion and the rotor mounting portion can be accommodated in the coil end of the stator. it can.

[0042]

As described above, according to the present invention, there is provided a cylindrical rotor core provided on the outer peripheral side of the stator.
A permanent magnet that is fixed to the inner peripheral side of the rotor core and is provided in the circumferential direction so as to face the stator, and a plurality of permanent magnets are disposed between the permanent magnet and the stator. At the center of the magnetic pole of the permanent magnet,
As the distance between the adjacent permanent magnets increases, the inner peripheral surface of the permanent magnet rotor increases.
Since the center of the magnetic pole of the permanent magnet is covered with a resin cylindrical member that is thinner and thicker as going to the gap,
Unlike the case where a metal cylindrical member is used, the scattering of the rotating permanent magnet can be prevented without causing loss due to eddy current. In addition, the circumference of the resin in molding can be improved, and the thickness of the resin at the center of the magnetic pole that requires a large amount of magnetic flux can be reduced, thereby preventing a decrease in characteristics due to an increase in the gap.

Further, according to the present invention, there is provided a bearing boss provided so as to protrude outward, and a rotating shaft penetrating the bearing boss and protruding outward from the bearing boss. A compression mechanism, a cylindrical stator fixed to the outer periphery of the bearing boss of the compression mechanism, and a tip protruding from the bearing boss of the rotating shaft, An umbrella-shaped rotor extending radially outward of the rotating shaft, and then extending in a cylindrical shape in the direction of the compression mechanism along the outer peripheral surface of the annular stator, wherein the stator and the umbrella-shaped rotor are provided. Since the compressor is driven by rotating the rotating shaft with an electric motor composed of a rotor, no extra member for fixing is required. In addition, since the stator and the umbrella-type rotor are directly fitted via the rotary shaft and the bearing boss without passing through the closed container, the centering between the stator and the umbrella-type rotor is easily performed. Thus, the motor gap can be easily made uniform. Further, the bearing boss portion and the rotor mounting portion can be accommodated in the coil end of the stator, and the whole can be made compact.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view at right angles to an axis of a permanent magnet rotor according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged view showing a second embodiment of the present invention.

FIG. 3 is a perspective view of a permanent magnet rotor according to a third embodiment of the present invention.

FIG. 4 is a perspective view of a permanent magnet rotor according to a fourth embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a permanent magnet rotor according to a fifth embodiment of the present invention.

FIG. 6 is a perspective view showing a cylindrical member used in a sixth embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a permanent magnet rotor according to a sixth embodiment of the present invention.

FIG. 8 is an axial sectional view showing an electric motor for a rotary compressor according to a seventh embodiment of the present invention.

FIG. 9 is an axial sectional view showing a main part of an electric motor for a rotary compressor according to an eighth embodiment of the present invention.

FIG. 10 is an axial sectional view showing a main part of an electric motor for a rotary compressor according to a ninth embodiment of the present invention.

FIG. 11 is a cross-sectional view at right angles to an axis showing a main part of a rotary compressor electric motor according to a tenth embodiment of the present invention.

FIG. 12 is a vertical cross-sectional view of a principal part of a rotary compressor electric motor according to an eleventh embodiment of the present invention.

FIG. 13 is a diagram illustrating correction of an unbalanced weight moment by an eccentric crankshaft of a conventional rotary compressor.

FIG. 14 is a cross-sectional view at right angles to an axis showing a main part of a rotary compressor electric motor according to a twelfth embodiment of the present invention.

FIG. 15 is a top view showing a rotor of a rotary compressor electric motor according to a thirteenth embodiment of the present invention.

FIG. 16 is a perspective view of a conventional permanent magnet rotor assembled by fixing permanent magnets with an adhesive.

FIG. 17 is a perspective view of a permanent magnet rotor assembled by fixing a conventional permanent magnet with a resin mold.

FIG. 18 shows a cross-sectional view of a conventional external rotation rotor type electric compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor core 21 Permanent magnet rotor 23 Permanent magnet 27 Central part 29 Between poles 31 Cylindrical member 33 Locking projection 47 Bottom wall part 51 Bolt or rivet 63 End plate 91 External rotation rotor type electric compressor 95 Compression mechanism part 99 rotating shaft 101 bearing boss 103 stator 105 umbrella type rotor 113 electric motor 123 cylindrical support 173 peephole

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 7/14 H02K 7/14 B 5H622 21/22 21/22 MF term (Reference) 3H003 AA05 AB04 AC03 AD03 CA01 CE03 CF05 3H029 AA04 AA13 AB03 BB44 CC07 CC16 CC27 CC39 5H002 AA07 AA08 AB04 AC03 AC06 5H607 AA12 BB07 BB14 BB17 CC01 CC03 CC05 CC09 DD02 DD08 FF07 JJ07 5H621 BB07 GA04 HH01 JK08 PP07 PP07 PP08

Claims (10)

[Claims] A cylindrical rotor core provided on an outer peripheral side of a stator, and a plurality of cylindrical rotor cores fixed on an inner peripheral side of the rotor core and arranged in a circumferential direction so as to face the stator. In the permanent magnet rotor having a permanent magnet, a gap between the permanent magnet and the stator is reduced at a center of a magnetic pole of the permanent magnet, and a gap between adjacent permanent magnets is provided. And the inner circumferential surface of the permanent magnet rotor is covered with a cylindrical member made of resin, the center of the magnetic pole of the permanent magnet being thinner and thinner as going to the gap between the poles. And a permanent magnet rotor. 2. The permanent magnet rotor according to claim 1, wherein a protrusion protruding from an inner peripheral surface of the rotor core is provided in the gap, and a permanent magnet is fixed by the protrusion. . 3. The cylindrical rotor core is provided at one axial end thereof with a bottom wall for transmitting the rotation of the rotary core to a rotating shaft, and the rotor core is formed by a plurality of blanks. 3. The permanent magnet rotor according to claim 1, wherein the plurality of punched plates are fixed to the bottom wall using bolts or rivets. 4. 4. An end plate for covering an end of said permanent magnet is provided on an end surface of said cylindrical rotor core opposite to said bottom wall. 3. The permanent magnet rotor according to 3. 5. The permanent magnet rotor according to claim 3, wherein an end of the cylindrical member on the bottom wall side is in contact with the bottom wall. 6. An end of the cylindrical member opposite to the bottom wall portion is provided with a flange-like flange extending radially outward from the end, and the flange is provided with the annular member. The permanent magnet rotor according to claim 4, wherein the permanent magnet rotor is sandwiched and fixed between an end plate and the permanent magnet. 7. A bearing boss provided to protrude outward,
A compression mechanism having a rotating shaft penetrating through the bearing boss and projecting outward from the bearing boss; and a cylindrical stator fixed to the outer periphery of the bearing boss of the compression mechanism. Provided at a tip end of the rotating shaft that protrudes from the bearing boss portion, extends radially outward from the tip end of the rotating shaft, and then compresses along the outer peripheral surface of the annular stator. An umbrella-shaped rotor extending cylindrically in the direction of a mechanism, comprising: an electric motor comprising the stator and the umbrella-shaped rotor, wherein the rotating shaft is rotated to drive a compressor. Compressor. 8. A cylindrical support is fixed to the inner peripheral surface of the stator,
The electric compressor according to claim 7, wherein an inner peripheral surface of the cylindrical support is fixed to the bearing boss. 9. The electric compressor according to claim 7, wherein the umbrella-shaped rotor has a viewing hole through which a gap between the umbrella-shaped rotor and the stator can be observed. 10. An electric compressor according to claim 7, wherein said umbrella-type rotor is the permanent magnet rotor according to claim 1.