JP2001073948A - Electric compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress loss-torque caused by magnetic attraction at a bearing part and iron loss by forming a electric motor part stored in a sealed container as a two- pole permanent magnet type wherein a permanent magnet is built in a rotary iron core of a rotor, and extendedly disposing a bearing part of a compression mechanism in a bore part formed on an end part of the rotor iron core. SOLUTION: In an electric compressor wherein a compression mechanism part 52 is disposed on a lower part in a sealed container 51 and a self-starting permanent magnet type synchronous electric motor 53 is disposed on an upper part thereof, the synchronous electric motor 53 is composed of a stator 67 wherein a coil is wound around a fixing iron core made of a laminated electromagnetic steel plate having a thickness L1, and a rotor 55 wherein two flat plate shaped permanent magnets 70a is built in a rotor iron core 68 made of a laminated electromagnetic steel plate. A bore part 69 is formed on an end part of a compression mechanism 52 side of the rotor 55, and a part of a non-magnetic material made bearing part 57 of the compression mechanism 52 is extendedly disposed in the bore part 69. Since there is no magnetic attraction between an inside of the bore part 69 and the bearing part 57, it is possible to suppress generation of loss torque and iron loss (especially, eddy current loss).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric compressor used for a refrigerator or an air conditioner.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to a reciprocating electric compressor shown in FIG.

[0003] In FIG. 7, reference numeral 1 denotes a hermetic container of an electric compressor, which comprises a compression mechanism 2 provided below the inside and an electric motor 3 provided above the compression mechanism 2. Reference numeral 4 denotes a shaft attached to the rotor 14 of the electric motor unit 3, and a crank unit 4a
It has.

Reference numeral 5 denotes a cylinder block made of a casting made of an iron-based material. The cylinder block 5 includes a bearing 6 into which the shaft 4 is inserted, and a cylinder 7 formed substantially at right angles to the bearing 6.

Reference numeral 9 denotes a piston that slides in the cylinder 7,
A compression chamber 10 is formed, and is connected to the crank part 4 a via a connecting rod 8. Numeral 11 denotes an oil supply pipe attached to the tip of the crank part 4a, and lubricating oil 12 stored at the bottom of the closed casing 1 is supplied to the compression mechanism part 2 and the shaft 4 so as to smoothly lubricate the sliding part. .

The motor unit 3 includes a stator 13 having windings wound around a stator core made of laminated electromagnetic steel sheets, and a rotor 14 having a rotor core 15 made of laminated electromagnetic steel sheets provided with a secondary conductor. Is a two-pole induction motor.

A bore 16 is provided at the end of the rotor core 15 on the side facing the compression mechanism 2, and the bearing 6 extends to the inside of the bore 16.

The operation of the conventional reciprocating electric compressor constructed as described above will be described.

Along with the rotation of the rotor 14, the piston 9 reciprocates via a connecting rod 8 connected to the crank portion 4a of the shaft 4, compressing the refrigerant gas in the compression chamber 10 and discharging the compressed gas into the discharge pipe (not shown). ) Is discharged toward systems such as refrigeration equipment and air conditioning equipment.

Here, oil is supplied to sliding parts such as the bearing 6, the cylinder 7, the connecting rod 8 and the piston 9 of the compression mechanism 2 by rotating an oil supply pipe 11 attached to the lower end of the shaft 4. The lubricating oil 12 is pumped up and supplied by a pump action.

In recent years, from the viewpoint of energy saving and miniaturization, studies have been actively conducted to reduce the power consumption of the refrigeration equipment and air conditioning equipment and to reduce the height direction. As a result, a part of the bearing is extended in the bore portion to suppress the runout of the rotor, and the overall height of the electric compressor is reduced.

However, it has not been possible to satisfy the demand for improving the efficiency of the electric motor which consumes the largest power in the refrigeration system.

For a two-pole induction motor conventionally used for an electric compressor, various studies have been made to improve the efficiency, such as adoption of a magnetic steel sheet having a low iron loss, optimization of the core shape, and increase in the amount of materials used. Was. However, induction motors require excitation power to form a magnetic circuit in addition to power for rotating a load by generating torque, so the efficiency of the motor tends to saturate. It is difficult to improve.

Therefore, as a means for further increasing the efficiency of the motor, a permanent magnet built into the rotor eliminates the need for excitation power and achieves high efficiency. We focused on applying to machines.

One embodiment of the self-starting permanent magnet type synchronous motor will be described with reference to FIGS.

Since only the electric motor section differs from the electric compressor, this point will be described.

Reference numeral 17 denotes a rotor of a synchronous motor, which comprises a rotor core 18 on which electromagnetic steel sheets are laminated, and a shaft hole 19 into which the shaft 4 is fitted. Reference numeral 20 denotes a bore provided at an axial end of the rotor core 18, though not shown, a part of the bearing 6 of the cylinder block 5 extends. 20a is a bore diameter of the bore portion 20.

Then, two flat magnets 21 of the same polarity are inserted into the rotor 17 in the shape of a mountain at a butting angle α to form one pole of the rotor magnetic pole, and the entire rotor has two poles. A rotor pole is formed. Here, P is the width dimension of the permanent magnet 21.

Also, a large number of conductor bars 22 provided on the rotor core 18 and short-circuit rings 23 located at both axial ends of the rotor core 18 are integrally formed by aluminum die casting to form a starting cage conductor. are doing.

Reference numeral 24 denotes an end plate made of a protective non-magnetic material for preventing the permanent magnet 21 from falling off. Numeral 25 denotes a magnetic flux short-circuit preventing barrier for preventing magnetic flux short-circuits between adjacent permanent magnets, and is formed by simultaneous molding of the starting cage conductor and aluminum die-casting.

Referring to FIG. 9, the flow of the magnetic flux of the permanent magnets 21 will be conceptually described by arrows, and the flow of the magnetic flux flowing inside each of the permanent magnets 21 is the magnetic flux flowing from the upper two permanent magnets 21. Is concentrated at the center of the rotor core 18 and is sucked into the two permanent magnets 21 shown in the lower part of the figure, but the magnetic flux density of the magnetic flux passing through the rotor core 18a near the outer periphery of the bore diameter 20a is very Get higher.

[0022]

As described above, it is conceivable to use a self-starting permanent magnet type synchronous motor instead of the conventional induction motor, but the bearing 6 made of an iron-based material is located inside the bore 20. Therefore, magnetic attraction acts between the inner periphery of the excited bore portion 20 and the bearing 6 to generate a loss torque that reduces the torque generated by the electric motor, and the magnetic flux of the permanent magnet 21 causes the magnetic flux of the permanent magnet 21 to move toward the bearing 6. It flows and iron loss (especially eddy current loss) occurs. In order to continue the operation while compensating for the loss torque and the iron loss (especially the eddy current loss), it is necessary to supply extra electric power corresponding to the electric motor as a motor, which is a factor that hinders an improvement in efficiency.

The present invention has been made in consideration of the above problems, and has as its object to provide a high-efficiency electric compressor in which loss torque and iron loss (particularly, eddy current loss) due to magnetic attraction at a bearing portion are reduced.

[0024]

SUMMARY OF THE INVENTION To achieve this object, the present invention provides an electric compressor equipped with a two-pole permanent magnet type electric motor, in which a bearing of a compression mechanism of the electric compressor is made of a non-magnetic material. This part is extended inside.

Further, in the present invention, the portion where the bearing of the compression mechanism extends inside the bore of the rotor core is made of a non-magnetic material.

Further, the rotor core and the end faces of the bearing portion do not overlap in a longitudinal section.

Further, a two-pole permanent magnet type electric motor has a rotor having a plurality of conductor bars of a starting cage conductor on the outer periphery of a rotor core, and a plurality of permanent magnets embedded inside thereof. It is a self-starting type permanent magnet synchronous motor provided.

Further, the permanent magnet is formed of a rare earth magnet.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a compression mechanism section housed in a closed container, and a motor section driven by being connected to the compression mechanism section. Is a two-pole permanent magnet type motor in which a permanent magnet is built in a rotor core of a rotor, wherein a bore portion is provided at an end of the rotor core facing the compression mechanism portion, and the compression mechanism portion is provided. The bearing portion extends inside the bore portion of the rotor core, and the bearing portion is formed of a non-magnetic material, and a magnetic attraction force is formed between the inner periphery of the bore portion and the bearing portion. Since it does not work, no loss torque occurs, and the magnetic flux from the permanent magnet is not attracted to the bearing portion because the bearing portion is non-magnetic, and almost all passes only through the rotor core, and There is almost no iron loss (especially eddy current loss) in the bearing, An effect that can provide a highly efficient electric compressor in which it reflects the high efficiency.

According to a second aspect of the present invention, there is provided a compression mechanism portion housed in a closed container, and a motor portion connected to and driven by the compression mechanism portion, wherein the motor portion is a rotor core of a rotor. A permanent magnet type electric motor having a permanent magnet incorporated therein, wherein a bore portion is provided at an end of the rotor core facing the compression mechanism portion, and a bearing portion of the compression mechanism portion is the rotor It extends inside the bore of the iron core, and this extended portion is made of a non-magnetic material. Since magnetic attraction does not work between the inner periphery of the bore and the bearing, Loss torque does not occur, and it is possible to prevent the occurrence of eddy current loss among iron losses in the bearing portion due to the magnetic flux of the permanent magnet, and it is inexpensive except for a portion extending the bearing portion inside the bore portion. Iron-based material, and the compression mechanism Since it is possible to da block integrally formed, it has an effect that it is possible to provide an inexpensive electric compressor with high efficiency.

According to a third aspect of the present invention, there is provided a compression mechanism section housed in a closed container, and an electric motor section connected to and driven by the compression mechanism section. The motor unit is a two-pole permanent magnet type motor in which a permanent magnet is built in a rotor core, and the rotor core and each end face of the bearing unit overlap each other in a projection line of a longitudinal section. Since there is no overlap, most of the magnetic flux does not flow to the bearing part side, so even if the bearing part is an iron-based material, loss torque and eddy current loss in the bearing part hardly occur Therefore, the efficiency of the motor can be directly reflected on the compressor. Further, the bearing can be formed integrally with an inexpensive iron-based material casting, so that the cost can be reduced.

According to a fourth aspect of the present invention, there is provided a two-pole permanent magnet type electric motor having a plurality of conductor bars of a starting cage conductor on an outer periphery of a rotor core, and a plurality of permanent magnets provided inside thereof. It is a self-starting permanent magnet type synchronous motor having a buried rotor.

According to a fifth aspect of the present invention, the permanent magnet is formed of a rare earth magnet. Since the rare earth magnet can obtain a strong magnetic force, the size and weight of the electric motor can be reduced, and the size of the electric compressor can be reduced. It has the effect that it can be achieved.

An embodiment of an electric compressor according to an embodiment of the present invention will be described below.

(Embodiment 1) A description will be given with reference to FIGS. FIG. 1 is a longitudinal sectional view of a compressor using a two-pole self-starting type permanent magnet synchronous motor, and FIG. 2 is a sectional view of the rotor of FIG.

In the figure, reference numeral 51 denotes a hermetically sealed container of an electric compressor, which includes a compression mechanism 52 provided below the inside thereof and a self-starting permanent magnet type synchronous motor 53 provided above the compression mechanism 52. ing. Reference numeral 54 denotes a shaft attached to a rotor 55 of the synchronous motor 53, and has a crank portion 56.

The compression mechanism 52 has a bearing 5 made of aluminum die-cast, which is a non-magnetic material, into which the shaft 54 is inserted.
7 and a cylinder block 60 made of a casting made of an iron-based material and having a cylinder 59 on which a piston 58 slides. The piston 58 is attached to the crank portion 56 with a connecting rod 61, and a compression chamber 62 is formed in the cylinder 59.
Is formed.

The bearing portion 57 and the cylinder block 6
0 is attached with a bolt B. This cylinder 59
A valve chamber 63 having a discharge valve and a suction valve (both not shown) is attached to the end of the valve chamber 63.

Reference numeral 64 denotes a suction muffler mounted on the suction valve side of the valve chamber 63.

Numeral 65 denotes an oil supply pipe attached to the tip of the crank portion 56, and lubricating oil 6 stored at the bottom of the closed container 51.
6 is guided to the sliding portion of the compression mechanism 52 to make lubrication smooth.

The synchronous motor 53 includes a stator 67 in which windings are wound around a fixed iron core made of laminated electromagnetic steel sheets having a thickness of L1 and a rotor 55 made up of a rotor iron core 68 made of laminated electromagnetic steel sheets. It is composed of A bore 69 is formed on the compression mechanism 52 side of the rotor 55, and a part of the bearing 57 extends into the bore 69.

Reference numeral 70a denotes a permanent magnet made of a neodymium-iron-boron ferromagnetic material, which is a two-plate type rare-earth magnet. Permanent magnets of the same polarity are inserted so as to abut each other in a mountain shape at a butting angle α '. The rotor 55 is arranged and buried in the axial direction of the rotor core 68. Two permanent magnets form one rotor magnetic pole, and the entire rotor 55 forms two rotor magnetic poles. The width of the permanent magnet is set to P '.

Here, the method of magnetizing the permanent magnet is as follows. The magnetizing method may be performed before or after the insertion into the rotor core 68. It is better to perform the magnetizing work after inserting and fixing.

Further, two permanent magnets of the same polarity are arranged in a mountain shape to form a single-pole rotor magnetic pole. One arc-shaped permanent magnet forms a single-pole rotor magnetic pole. You may.

Then, a large number of conductor bars 71 provided on the rotor core 68 and short-circuit rings 72 located at both ends in the axial direction of the rotor core 68 are integrally formed by aluminum die casting to form a starting cage conductor. Has formed. 73 is a permanent magnet 70
a, 70b are non-magnetic end plates for protection from falling off.

Reference numeral 74 denotes a magnet short-circuit preventing barrier for preventing magnetic flux short-circuiting between adjacent permanent magnets. The barrier 74 has a slot-like hole and is formed by simultaneous molding of the starting cage conductor and aluminum die-casting. Die cast is filled.

Next, the flow of the magnetic flux of the permanent magnets 70a and 70b will be conceptually described with reference to the arrow line in FIG. Through the lower two permanent magnets 70
It is sucked into b.

At this time, since the rotor core 68 has a partially narrow magnetic path, the magnetic flux density becomes very high, but the bearing 57 extending inside the bore 69 is nonmagnetic. Since it is made of aluminum die-cast material, no magnetic attraction acts between the inner periphery of the bore portion 69 and the bearing portion 57, so that no loss torque occurs. Further, since the bearing portion does not attract the magnetic flux, the magnetic flux does not flow into the bearing portion 57, so that loss such as generation of iron loss (particularly eddy current loss) in the bearing portion 57 does not occur.

Therefore, the electric compressor can reflect the high efficiency of the electric motor, and can provide a high-efficiency electric compressor.

Although the bearing 57 is fixed to the cylinder block 60 by bolts in FIG. 1, the bearing 57 may be fixed to the cylinder block 60 by shrink fitting or press fitting as shown in FIG.

(Embodiment 2) A description will be given with reference to FIG. 4, but the same components as those described in Embodiment 1 will be assigned the same reference numerals and detailed description thereof will be omitted.

Reference numeral 75 denotes a bearing portion made of a non-magnetic material such as aluminum die cast into which the shaft 54 is inserted. Reference numeral 76 denotes a cylinder block made of a casting made of an iron-based material. The cylinder block 76 is formed by sliding a bearing portion 77 into which the shaft 54 is inserted and a piston 58 attached to the crank portion 56 of the shaft 54 by a connecting rod 61. And a cylinder 59 that forms The bearing 75 extends into the bore 69, and is fitted and connected to the bearing 77 of the cylinder block 76 outside the bore 69.

As a result, no magnetic attraction force acts between the inner periphery of the bore portion 69 and the bearing portion, so that no loss torque occurs, no eddy current loss occurs in the bearing portion 75, and high efficiency is achieved. An electric compressor can be realized.

Although the example in which the bearing portion 75 is made of an aluminum-based material has been described, it may be formed of another non-magnetic material such as a bearing made of a copper-based or ceramic material.

Also, since only the bearing 69 needs to be made of a non-magnetic material, the bearing 77 and the cylinder block 76 can be integrally formed of an inexpensive iron-based material, so that a highly efficient and inexpensive electric compressor is provided. can do.

(Embodiment 3) A description will be given with reference to FIGS.

FIG. 5 is a longitudinal sectional view of the electric compressor of the present embodiment, and FIG. 6 is an enlarged transverse sectional view of a main part of FIG.

In the figure, reference numeral 101 denotes a hermetically sealed container of an electric compressor, which comprises a compression mechanism 102 provided below the interior thereof and a self-starting permanent magnet type synchronous motor 103 provided above the compression mechanism 102. ing. 104 is a synchronous motor 1
03, the shaft attached to the rotor 105
6 is provided.

Reference numeral 107 denotes a bearing formed of a casting of an iron-based material, and is formed integrally with a cylinder block 200 having a cylinder 109 on which a piston 208 slides. The piston 202 is attached to the crank section 106 via a connecting rod 201 to form a compression chamber 202 in the cylinder 200.

A valve chamber 203 having a discharge valve and a suction valve (both not shown) is attached to the tip of the cylinder 200.

Reference numeral 204 denotes a suction muffler mounted on the suction valve side of the valve chamber 203.

Reference numeral 205 denotes an oil supply pipe attached to the tip of the crank section 106. The oil supply pipe 205 guides the lubricating oil 206 stored at the bottom of the closed vessel 101 to the sliding section of the compression mechanism section 102 to make lubrication smooth. I have.

Further, the synchronous motor 103 has a thickness L2
And a rotor 105 composed of a rotor core 108 made of laminated electromagnetic steel sheets.

The rotor 105 is not provided with a bore, and the end face 107a of the bearing 107 on the motor side.
Are arranged apart from the end face of the rotor core 108 so that the rotor core and the end faces 108a and 107a of the bearing portion do not overlap with each other on the projection line of the longitudinal section.

Reference numerals 300a and 300b denote neodymium-iron-boron-based ferromagnetic permanent magnets, which are two plate-shaped rare earth magnets, and are inserted in such a manner that permanent magnets of the same polarity are butt-shaped at a butt angle β. The permanent magnets are arranged and buried in the axial direction of the rotor core 108, and two permanent magnets form one rotor magnetic pole, and the entire rotor 105 forms two rotor magnetic poles. The width of the permanent magnet is set to Q.

Here, the method of magnetizing the permanent magnet is as follows. The magnetizing method may be performed before or after insertion into the rotor core 108. It is better to perform the magnetizing work after inserting and fixing.

Further, two permanent magnets of the same polarity are arranged in a mountain shape to form a single rotor magnetic pole. However, one rotor permanent magnet is formed by one arc-shaped permanent magnet. You may.

Then, a number of conductor bars 301 provided on the rotor core 108 and short-circuit rings 302 located at both ends in the axial direction of the rotor core 105 are integrally formed by aluminum die casting to form a starting cage conductor. Has formed. Reference numeral 303 denotes a non-magnetic end plate for protecting the permanent magnets 300a and 300b from falling off.

Reference numeral 304 denotes a magnet short-circuit prevention barrier for preventing magnetic flux short-circuit between adjacent permanent magnets, which is formed by slot-shaped holes. The starting cage conductor and aluminum die-casting are simultaneously molded. Is filled.

It should be noted that when compared with the first and second embodiments, L2
<L1, β> α ′, Q> P ′.

Therefore, it can be considered that the amount of magnetic flux by the permanent magnet taken out from the rotor 105 is obtained substantially in proportion to the product of the magnet width and the axial length, that is, the magnetic pole area of the magnet.

Therefore, in the present embodiment, by increasing the butting angle of the permanent magnet from α ′ to β and increasing the width of the permanent magnet from P ′ to Q, the length of the permanent magnet in the axial direction can be increased. The rotor core 108 can be shortened.
Of the laminated electromagnetic steel sheet can be reduced.

On the other hand, the thickness of the laminated electromagnetic steel sheet of the stator 207 is changed from L1 to L2 by enlarging the magnetic path of the stator core.
, And can correspond to the thickness of the rotor core 108.

As a result, the size in the height direction of the compressor can be reduced even if there is no bore portion by reducing the thickness of the bore portion 69 in the first and second embodiments. Even if the bearing portion 107 is made of an iron-based material, the end face 107a of the bearing portion 107 is located away from the end face of the rotor core 108, so that the torque loss due to the magnetic attraction force and the bearing portion 107
The occurrence of eddy current loss in the inside is due to the magnetic flux leaking from the end face of the rotor core 108, but is extremely small and negligible as compared with the case of the iron-based material extending into the bore. .

Therefore, the bearing portion 107 can be formed integrally with the cylinder block 200 using an inexpensive iron-based casting, and since there is no bore portion in the rotor, the rotor can be easily manufactured and the height of the compressor can be reduced. A highly efficient and inexpensive compressor can be provided without increasing the size.

Although the first to third embodiments have been described with reference to the self-starting type permanent magnet synchronous motor, the conductor bar 71 of the rotor can also be used in a two-pole DC brushless motor.
And the short-circuit ring 72 (that is, the cage-shaped conductor for starting) is common, in that the permanent magnet is buried in the rotor, and the positional relationship between the permanent magnet, the bore, and the bearing is similarly set. By doing so, the same operation and effect can be obtained.

[0077]

The invention according to claim 1 of the present invention comprises a compression mechanism housed in a closed container, and a motor section connected to and driven by the compression mechanism section, wherein the motor section rotates. A two-pole permanent magnet type motor having a permanent magnet incorporated in a rotor core of a rotor, wherein a bore portion is provided at an end of the rotor core on a side facing the compression mechanism portion, and a bearing of the compression mechanism portion is provided. The portion extends inside the bore portion of the rotor core, and the bearing portion is formed of a non-magnetic material. Since there is no magnetic attraction between the inner periphery of the bore portion and the bearing portion, No loss torque is generated, and the magnetic flux from the permanent magnet passes almost only through the rotor core because the bearing is non-magnetic, so that eddy current loss hardly occurs in the bearing, Providing high-efficiency electric compressors that directly reflect the high efficiency of electric motors It has the effect of kill.

According to the second aspect of the present invention, since only the portion of the bearing of the compression mechanism extending inside the bore of the rotor core is made of a non-magnetic material, loss torque due to magnetic attraction is reduced. The occurrence of eddy current loss in the bearing portion due to the magnetic flux of the permanent magnet can be prevented, and the portion other than the portion where the bearing portion extends inside the bore portion can be made of an inexpensive iron-based material. Since it can be formed integrally with the cylinder block of the compression mechanism, it has the effect that a highly efficient and inexpensive electric compressor can be obtained.

According to a third aspect of the present invention, there is provided a compression mechanism portion housed in a closed container, and an electric motor portion connected to and driven by the compression mechanism portion, wherein a bearing portion of the compression mechanism portion is made of iron. The motor unit is a two-pole permanent magnet type motor in which a permanent magnet is built in a rotor core, wherein the motor unit is a two-pole permanent magnet type motor, and each end face of the rotor core and the bearing unit does not overlap in a longitudinal section. Since almost no loss torque or eddy current loss occurs in the bearing portion, a highly efficient electric compressor that reflects the high efficiency of the electric motor can be obtained. In addition, since the bearing portion can be formed of an inexpensive iron-based casting, an inexpensive compressor can be provided. The invention according to claim 4 is a two-pole permanent magnet type electric motor, having a starting cage conductor on a rotor core,
By providing a self-starting permanent magnet type synchronous motor having a rotor having a plurality of permanent magnets embedded therein, a high efficiency of the synchronous motor can be provided to the compressor.

Further, in the invention according to claim 5, the permanent magnet is formed of a rare earth magnet. Since the rare earth magnet can obtain a strong magnetic force, the size and weight of the electric motor can be reduced, and the size of the electric compressor can be reduced. This has the effect of achieving the following.

[Brief description of the drawings]

FIG. 1 is a vertical partial sectional view of a first embodiment according to the present invention.

FIG. 2 is a cross-sectional view of the rotor of FIG. 1;

FIG. 3 is a vertical partial cross-sectional view of an electric compressor according to a second embodiment of the present invention.

FIG. 4 is a vertical partial sectional view of FIG. 3;

FIG. 5 is a vertical partial sectional view of a third embodiment according to the present invention.

FIG. 6 is a cross-sectional view of the rotor of FIG. 5;

FIG. 7 is a vertical partial sectional view of a conventional electric compressor.

FIG. 8 is an axial cross-sectional view of a rotor in a conventional two-pole self-starting permanent magnet synchronous motor.

FIG. 9 is a cross-sectional view of a conventional rotor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 51 airtight container 52 compression mechanism 53 motor unit 55 rotor 68 rotor core 57 bearing 69 bore 70 a, 70 b permanent magnet

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 21/14 H02K 21/14 M (72) Inventor Tatsuyuki Iizuka 4-2-2 Takaidamoto-dori, Higashi-Osaka-shi, Osaka No. 5 Inside Matsushita Refrigeration Machinery Co., Ltd. F-term (reference) in Sangyo Co., Ltd. CA02 CA12 CB03 DD02 PP10 PP19

Claims (5)

[Claims] A compression mechanism housed in a closed container;
A motor unit connected to and driven by the compression mechanism unit, wherein the motor unit is a two-pole permanent magnet type motor having a permanent magnet incorporated in a rotor core of a rotor, wherein the compression of the rotor core is performed. A bore portion is provided at an end on the side facing the mechanism portion, the bearing portion of the compression mechanism portion extends inside the bore portion of the rotor core, and the bearing portion is formed of a non-magnetic material. Characteristic electric compressor. 2. A compression mechanism unit housed in a closed container,
A motor unit connected to and driven by the compression mechanism unit, wherein the motor unit is a two-pole permanent magnet type motor having a permanent magnet incorporated in a rotor core of a rotor, wherein the compression of the rotor core is performed. A bore is provided at an end on the side facing the mechanism, the bearing of the compression mechanism extends inside the bore of the rotor core, and the extended portion is made of a non-magnetic material. Characteristic electric compressor. 3. A compression mechanism housed in a closed container,
A motor portion connected to and driven by the compression mechanism portion, wherein a bearing portion of the compression mechanism portion is formed of an iron-based material, and the motor portion is a two-pole permanent magnet having a rotor core and a built-in permanent magnet. An electric compressor, wherein the rotor core and the end faces of the bearing portion do not overlap with each other in a projection line of a longitudinal section. 4. A two-pole permanent magnet type motor has a rotor having a plurality of conductor bars of a starting cage conductor on an outer periphery of a rotor core, and a plurality of permanent magnets embedded inside the bar. The electric compressor according to any one of claims 1 to 3, wherein the electric compressor is a self-starting permanent magnet type synchronous motor provided. 5. The electric compressor according to claim 1, wherein the permanent magnet is formed of a rare earth magnet.