JP2004245073A - Electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric compressor which is high in efficiency and reliability with respect to the electric compressor. <P>SOLUTION: When a shaft 104 receives an unbalanced load owing to a magnetic attraction generated between a rotor 114 and a stator 113, it receives the unbalanced load as the fulcrum at the end of a counter-main bearing side of an auxiliary bearing inner wall in the diagonal direction with respect to a center axis of the end of a counter-auxiliary bearing side and the shaft 104 in the main bearing inner wall so that the shaft 104 is made small in the inclined angle in the bearing on the extension of the distance between the fulcrums. As a result, it is hard to generate a partial contact between the bearing and the shaft 104 so as to avoid a sliding loss owing to the partial contact, enabling the maintenance of the stable efficiency. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to an electric compressor used for a refrigerator or an air conditioner.
[0002]
[Prior art]
In recent years, for electric compressors used in refrigeration systems such as home refrigerators and the like, in order to reduce power consumption, the viscosity of lubricating oil has been reduced, and the efficiency has been improved by using inverter drives and synchronous motors. I have. Further, in order to increase the volumetric efficiency of the refrigerator, a more compact compressor is desired.
[0003]
As a conventional electric compressor, there is one in which a stator and a main bearing are improved in order to improve efficiency (for example, see Patent Document 1).
[0004]
Hereinafter, the conventional electric compressor will be described with reference to the drawings.
[0005]
FIG. 7 is a longitudinal sectional view of a conventional electric compressor. In FIG. 7, a hermetic container 1 of the electric compressor stores a lubricating oil 12 at a bottom portion, and accommodates an electric motor portion 3 including a stator 13 and a rotor 14 and a compression mechanism portion 2 driven by the electric motor portion 3.
[0006]
Next, details of the compression mechanism 2 will be described below.
[0007]
A cylinder block 5 having a substantially cylindrical cylinder 7 constituting the compression mechanism 2 is made of an aluminum-based material, which is a non-magnetic material and is formed substantially perpendicular to the cylinder 7 while supporting the shaft 4. A bearing 6 is provided. The shaft 4 having the eccentric portion 4a is fitted to the bearing portion 6 and the rotor 14 is fixed.
[0008]
A piston 9 that slides in the cylinder 7 forms a compression chamber 10 and is connected to the eccentric portion 4a via a connecting rod 8 as connecting means. An oil supply pipe 11 is attached to the tip of the eccentric part 4a.
[0009]
Next, details of the motor unit 3 will be described below.
[0010]
The motor unit 3 includes a stator 13 in which a winding is wound around a stator core made of laminated electromagnetic steel sheets, and a rotor 14 having a permanent magnet 15b built in a rotor core 15 made of laminated electromagnetic steel sheets. It is a pole induction motor. A hollow bore 16 is provided at an end of the rotor core 15 on the side facing the compression mechanism 2, and the bearing 6 extends inside the hollow bore 16. .
[0011]
Next, the operation of the conventional reciprocating electric compressor configured as described above will be described.
[0012]
The shaft 4 rotates with the rotation of the rotor 14 of the motor unit 3, and the rotational motion of the eccentric part 4 a of the shaft 4 is transmitted to the piston 9 via the connecting rod 8, so that the piston 9 reciprocates in the compression chamber 10. Exercise. As a result, the refrigerant gas from the cooling system (not shown) is sucked and compressed into the compression chamber 10, and then continuously discharged again to the cooling system such as the freezing and refrigeration equipment and the air conditioning equipment.
[0013]
In addition, with the rotation of the shaft 4, the oil supply pipe 11 attached to the lower end of the shaft 4 rotates, and the lubricating oil 12 is pumped upward by the centrifugal pumping action. 7, lubricated to sliding parts such as connecting rod 8 and piston 9.
[0014]
[Patent Document 1]
JP 2001-73948 A
[Problems to be solved by the invention]
However, in the above-described conventional configuration, if there is a deviation in the spatial distance between the rotor 14 and the stator 13, a force for attracting the rotor 14 to a smaller spatial distance, that is, a magnetic attraction force is generated. In particular, when the permanent magnet 15b incorporated in the rotor core 15 is a permanent magnet 15b having a strong magnetic force such as a rare earth element, the magnetic attractive force acts as a large force when the deviation of the space distance is large.
[0016]
As a result, the shaft 4 fixed to the rotor 14 and fitted in the bearing portion 6 is inclined in the bearing portion 6, and a one-side contact occurs between the bearing portion 6 and the shaft 4. If the shaft 4 rotates and slides in the bearing portion 6 in such a one-sided contact state, the sliding surfaces of both the bearing portion 6 and the shaft 4 may be worn.
[0017]
Further, in another conventional example described in the above prior art, a structure is disclosed in which the main bearing end face of the iron-based material and the end face of the compression mechanism side of the rotor core do not overlap. If the required bearing length of the cantilever bearing type bearing portion 6 is maintained, the overall length of the shaft 4 becomes longer, and accordingly the distance between the center of gravity of the rotor 14 and the bearing portion 6 becomes longer. The magnetic attraction generated between the bearings 6 acts as a strong moment in the bearing 6, so that the force per piece generated between the bearing 6 and the shaft 4 is further increased, and the sliding of both the bearing 6 and the shaft 4 is performed. There is a disadvantage that the surface may be worn.
[0018]
An object of the present invention is to provide an electric compressor with high efficiency and high reliability.
[0019]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention is configured such that a lubricating oil is stored in a sealed container, and an electric element including a stator and a rotor having a permanent magnet incorporated in a rotor core, and the electric element is driven by the electric element. A shaft having an eccentric shaft portion and a sub shaft portion and a main shaft portion provided coaxially vertically with the eccentric shaft portion interposed therebetween, and a cylinder block having a compression chamber. The main shaft portion axis, which is disposed in the cylinder block so as to be substantially perpendicular to the axis of the compression chamber, supports the main shaft portion of the shaft, and includes an end of the rotor core on the side of the compression mechanism. A main bearing that does not intersect with a plane substantially orthogonal to the axis, a sub-bearing disposed on the cylinder block and supporting the sub-shaft, a piston reciprocating in the compression chamber, and connecting the piston and the eccentric shaft. Connecting means Even though the bearing is a magnetic material, it is arranged so that the rotor and the main bearing do not intersect, so there is almost no eddy current loss in the main bearing, and the angle at which the shaft tilts in the bearing part Has an effect that it is difficult to generate one-sided contact between the bearing portion and the shaft.
[0020]
The invention according to claim 2 is an electric element comprising a stator and a rotor having a permanent magnet incorporated in a rotor core while storing lubricating oil in a closed container, and a compression element driven by the electric element. A shaft having an eccentric shaft portion and a sub shaft portion and a main shaft portion provided coaxially up and down with the eccentric shaft portion interposed therebetween, a cylinder block including a compression chamber, and the cylinder A main bearing disposed on the block so as to be substantially perpendicular to the axis of the compression chamber and supporting the main shaft of the shaft; and a sub-bearing disposed on the cylinder block and supporting the sub-shaft. A piston that reciprocates in the compression chamber, and coupling means for coupling the piston and the eccentric shaft, wherein the rotor has a hollow bore at an end of the rotor core on the compression mechanism side. Part, the main bearing is The rotor is made of a magnetic material and extends inside the bore of the rotor core. Since the bearing is a non-magnetic material, the magnetic flux from the permanent magnet causes iron loss (particularly eddy current loss). ) Does not occur, high efficiency can be achieved, and the longer bearing length of the main bearing reduces the surface pressure and improves reliability. In addition, the distance between fulcrum points is increased due to the double-sided bearing, and the bearing part In this configuration, the angle at which the shaft is inclined becomes smaller, so that the shaft has a function of making it less likely to cause a contact between the bearing portion and the shaft.
[0021]
According to a third aspect of the present invention, in addition to the first or second aspect of the present invention, the permanent magnet incorporated in the rotor core is made of a rare earth element. The permanent magnet that obtains a strong magnetic force by the operation of the invention described in (1) can be used, and has the effect of realizing high energy efficiency.
[0022]
According to a fourth aspect of the present invention, in addition to any one of the first to third aspects of the present invention, an inverter drive driven at a plurality of operating frequencies including a rotational frequency equal to or higher than the commercial power supply frequency is provided. According to the first to third aspects of the present invention, it is possible to operate at a higher rotation speed.
[0023]
According to a fifth aspect of the present invention, in addition to the fourth aspect, the stator has a plurality of radially formed teeth portions on an iron core, and a winding is directly wound on the teeth portions via an insulating member. In addition to the effect of the invention according to claim 4, the overall height of the stator is reduced, so that the overall height of the electric compressor is reduced, and the spatial distance between the rotor and the stator is uniform. It has an effect that the magnetic attraction force can be suppressed small.
[0024]
According to a sixth aspect of the present invention, in addition to any one of the first to third aspects of the present invention, the electric element is started as an induction motor at the time of starting, and the synchronous operation is performed by performing the synchronous pull-in near the synchronous rotational speed to perform the synchronous operation. The motor according to the present invention has a function of achieving high energy efficiency by employing a synchronous motor capable of obtaining high efficiency by the operation of the inventions of claims 1 to 3.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an electric compressor according to the present invention will be described with reference to the drawings. In addition, about the same structure as a conventional one, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
[0026]
(Embodiment 1)
FIG. 1 is a vertical sectional view of the electric compressor according to Embodiment 1 of the present invention.
[0027]
In FIG. 1, a closed casing 101 houses a compression mechanism section 102 and an electric motor section 103 for driving the compression mechanism section.
[0028]
The refrigerant sealed in the closed vessel 101 is R134a having an ozone depletion potential of zero, a hydrocarbon-based refrigerant having a low global warming potential represented by R600a, or the like. A lubricating oil 112 having a viscosity of 5 to 10 [cts] compatible with the refrigerant is stored in the closed container 101.
[0029]
Next, details of the compression mechanism 102 will be described below.
[0030]
The shaft 104 has a sub-shaft portion 118 and a main-shaft portion 116 provided coaxially up and down with the eccentric shaft portion 117 interposed therebetween. The lubrication mechanism 111 formed on the shaft 104 has one end communicating with the lubricating oil 112 and the other end communicating with the upper end of the shaft 104.
[0031]
The cylinder block 105 is made of cast iron, and a substantially cylindrical compression chamber 110 and a main bearing 120 that supports the main shaft portion 116 are integrally formed, and a sub bearing 121 that supports the sub shaft portion 118 is fixed. I have. The piston 109 is reciprocally slidably inserted into the compression chamber 110, and the piston 109 and the eccentric shaft 117 are connected by a connecting rod 108 as connecting means.
[0032]
Next, details of the motor unit 103 will be described below.
[0033]
The motor unit 103 includes a stator 113 and a rotor 114, and is driven by an arbitrary plurality of operating frequencies such as 30 [HZ], 50 [HZ], 70 [HZ], and 80 [HZ]. It is. The stator 113 has a plurality of radially formed teeth portions 113b on an iron core 113a, and the teeth portions 113b are directly provided with windings 113d via insulating members 113c to form a concentrated winding motor. I have. The rotor 114 is fixed to the main shaft portion 116 of the shaft 104 and includes a permanent magnet 115 a built in the rotor core 115.
[0034]
The permanent magnet 115a is made of, for example, a rare earth magnet such as neodymium, iron, or boron-based ferromagnetic material. The main bearing 120 does not intersect a virtual plane that includes the compressor element side end 115b of the rotor core 115 and that is substantially perpendicular to the axis of the compression chamber 110.
[0035]
The operation of the electric compressor configured as described above will be described below.
[0036]
When the stator 113 is energized, the rotor 114 rotates the shaft 104, and the eccentric movement of the eccentric shaft 117 is transmitted to the piston 109 via the connecting rod 108, so that the piston 109 reciprocates in the compression chamber 110. I do. Thereby, the refrigerant gas is sucked and compressed into the compression chamber 110 from the cooling system (not shown), and is then discharged again to the cooling system.
[0037]
The lubricating oil 112 is pumped up by an oil supply mechanism 111 formed on the shaft 104 and discharged from the upper end of the shaft 104.
[0038]
Here, the permanent magnet 115a incorporated in the rotor core 115 is made of a material having a strong magnetic force, such as a rare earth element, and therefore has a particularly strong magnetic force, and an extremely strong magnetic attraction in a portion where the distance between the rotor 114 and the stator 113 is small. Force is generated.
[0039]
However, when the shaft 104 receives an eccentric load due to the magnetic attraction generated between the rotor 114 and the stator 113, the conventional cantilever bearing has a diagonal direction with respect to the central axis of the shaft 104 on the inner wall of the main bearing. In contrast, the two-sided bearing has an eccentric load with its upper and lower ends serving as fulcrums. The eccentric load is received with the end of the side opposite to the main bearing as a fulcrum, and the distance between the fulcrums becomes about twice as long.
[0040]
The extension of the distance between the fulcrums means that the angle of inclination of the shaft 104 in the bearing portion is reduced, and as a result, a one-sided contact between the bearing portion and the shaft 104 is less likely to occur. Sliding loss is avoided, and stable efficiency can be maintained. At the same time, it is possible to suppress the sliding noise generated by the one-side contact, and to realize an electric compressor with low noise. Further, since the load applied to the shaft 104 during the operation of the compressor is held at both the upper and lower positions around the eccentric shaft portion 117 (fulcrum) to which the compression load from the piston 109 is applied, the fulcrum (the eccentric shaft portion 117) is held. 2), the load can be distributed substantially evenly, and the reliability of the sliding portion of the shaft 104 can be improved as compared with the cantilever type in which the load is concentrated only on one bearing portion.
[0041]
Further, since the load on the shaft 104 applied during the operation of the compressor is small in the amount of twisting and is applied over a wide area, the surface pressure of the main bearing 120 and the sub-bearing 121 is reduced, and the length of the main bearing 120 is shorter than that of the cantilever bearing. Can be shortened, the overall height of the compressor can be reduced, and the viscous resistance at the sliding portion can be reduced with a decrease in the sliding length. As a result, high efficiency can be realized.
[0042]
Since the main bearing 120 is formed integrally with the cylinder block 105, the main bearing 120 is made of cast iron which is an iron-based material. However, since the rotor core 115 and the main bearing 120 are disposed so as not to intersect with each other, the main bearing 120 is incorporated in the rotor core 115. Since the lines of magnetic force of the permanent magnet 115a hardly interfere with the main bearing 120, eddy current loss hardly occurs in the main bearing portion, and high efficiency can be obtained.
[0043]
Further, the motor unit 103 is driven by an inverter, and when a high rotation speed operation such as 70 to 80 HZ is performed depending on the load, the magnetic attraction force is increased, and even if the force for tilting the shaft 104 is increased, the shaft 104 is supported by the main bearing. The structure can be prevented from tilting due to the double-sided bearing configuration in which both bearings 120 and the auxiliary bearing 121 support the shaft. Sliding loss can be reduced, high efficiency can be maintained, and one-side contact due to shaft tilt can be prevented. The performance is improved.
[0044]
In addition, when the motor unit 103 is driven at a low rotation speed of 30 HZ by the inverter drive, the shaft 104 is supported by both the main bearing 120 and the sub-bearing 121, so that the bearing can be prevented from tilting. Since the sliding loss can be reduced, sufficient reliability can be obtained even with a lubricating oil 112 having a low viscosity of 5 to 10 [cts].
[0045]
Furthermore, the stator 113 has a plurality of radially formed teeth portions 113b on the iron core 113a, and the windings 113d are directly applied to the teeth portions 113b via insulating members 113c, so that the distributed winding is performed. In addition, there is no necessary coil end, and the total height of the stator 113 and the rotor 114 can be reduced by directly applying the winding 113d to the teeth portion 113b via the insulating member 113c, so that the total height of the electric compressor is further reduced. It is possible to suppress. Since the total height of the stator 113 and the rotor 114 is low, the gap size between the stator 113 and the rotor 114 can be easily made uniform. As a result, magnetic attraction is hardly generated, so that the change is less likely to occur. Input and noise increase can be avoided.
[0046]
In the present embodiment, as a connecting means for connecting the piston and the eccentric shaft, a connecting means such as a ball joint or a Scotch yoke may be applied instead of the connecting lot.
[0047]
(Embodiment 2)
FIG. 2 is a longitudinal sectional view of the electric compressor according to Embodiment 2 of the present invention.
[0048]
The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.
[0049]
In FIG. 2, the motor unit 203 includes a stator 213 in which a winding is wound around a stator core made of laminated electromagnetic steel sheets, and a rotor 214 in which a secondary conductor is provided on a rotor core 215 made of laminated electromagnetic steel sheets. It is a two-pole synchronous motor configured. The rotor core 215 contains a permanent magnet 215a made of, for example, a rare earth magnet such as neodymium, iron, or a boron-based ferromagnetic material. Other configurations are the same as those of the first embodiment.
[0050]
Next, the operation of the electric compressor configured as described above will be described.
[0051]
The electric element starts as an induction motor at the time of starting, and performs the synchronous operation by pulling in the synchronous near the synchronous rotational speed.
[0052]
Here, since the permanent magnet 215a built in the rotor core 215 is made of a material having a strong magnetic force such as a rare earth element, the magnetic force is particularly strong, and extremely strong magnetic attraction is applied to a portion where the distance between the rotor 214 and the stator 213 is small. Force is generated. However, with the same configuration as in the third embodiment, problems due to strong magnetic attraction can be avoided, and as a result, the high efficiency of the synchronous motor can be effectively utilized, high energy efficiency can be obtained, and the inclination of the shaft can be improved. Can be prevented, and the reliability is improved.
[0053]
(Embodiment 3)
FIG. 3 is a longitudinal sectional view of the electric compressor according to Embodiment 3 of the present invention.
[0054]
The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.
[0055]
In FIG. 3, a closed casing 101 accommodates a compression mechanism 302 and an electric motor 303 for driving the compression mechanism.
[0056]
A cylinder block 305 constituting the compression mechanism 302 is made of cast iron, forms a substantially cylindrical compression chamber 110, and has a main bearing 320 that supports the main shaft 116 of the shaft 104 and a sub bearing that supports the sub shaft 118. The bearing 121 is fixed to the cylinder block 305.
[0057]
The motor unit 303 is an inverter-driven motor that includes the stator 113 and the rotor 314 and is driven at a plurality of operating frequencies. The rotor 314 is fixed to the main shaft portion 116 of the shaft 104 and includes a permanent magnet 315 a built in the rotor core 315. The permanent magnet 315a is made of, for example, a rare earth magnet such as neodymium, iron, or a boron-based ferromagnetic material. The rotor core 315 has a hollow bore 306 formed at the end face on the compression mechanism 302 side.
[0058]
The main bearing 320 is made of an aluminum alloy, which is a non-magnetic material, and extends inside the bore 306 of the rotor core 315.
[0059]
The operation of the electric compressor configured as described above will be described below.
[0060]
When the stator 113 is energized, the rotor 314 rotates the shaft 104, and the eccentric motion of the eccentric shaft 117 is transmitted to the piston 109 via the connecting rod 108, so that the piston 109 reciprocates in the compression chamber 110. I do. Thereby, the refrigerant gas is sucked and compressed into the compression chamber 110 from the cooling system (not shown), and is then discharged again to the cooling system. The lubricating oil 112 is pumped up by an oil supply mechanism 111 formed on the shaft 104 and discharged from the upper end of the shaft 104.
[0061]
Here, since the permanent magnet 315a built in the rotor core 315 is made of a material having a strong magnetic force such as a rare earth element, the magnetic force is particularly strong, and extremely strong magnetic attraction is applied to a portion where the distance between the rotor 314 and the stator 113 is small. Force is generated.
[0062]
When the shaft 104 receives an eccentric load due to the magnetic attraction generated between the rotor 314 and the stator 113, the conventional cantilever bearing moves up and down diagonally with respect to the center axis of the shaft 104 on the inner wall of the main bearing. While the eccentric load is received with the end as a fulcrum, the structure of this doubly supported bearing is such that the opposite end of the inner wall of the main bearing opposite to the side of the auxiliary bearing and the inner wall of the auxiliary bearing which is diagonal to the center axis of the shaft 104 are opposed. An eccentric load is applied with the end on the main bearing side as a fulcrum, but the distance between the fulcrum is much longer than that of a conventional cantilever bearing. Moreover, since the main bearing 120 extends inside the bore portion 106, the distance between the fulcrums becomes further longer.
[0063]
The extension of the distance between the fulcrums means that the angle of inclination of the shaft 104 in the bearing portion is reduced, and as a result, a one-sided contact between the bearing portion and the shaft 104 is less likely to occur. Sliding loss is avoided, and stable efficiency can be maintained. At the same time, it is possible to suppress the sliding noise generated by the one-side contact, and to realize an electric compressor with low noise.
[0064]
Further, since the load applied to the shaft 104 during the operation of the compressor is held at both the upper and lower positions around the eccentric shaft portion 117 (fulcrum) to which the compression load from the piston 109 is applied, the fulcrum (the eccentric shaft portion 117) is held. 2), the load can be distributed substantially evenly, and the reliability of the sliding portion of the shaft 104 can be improved as compared with the cantilever type in which the load is concentrated only on one bearing portion.
[0065]
At this time, since the main bearing 120 is made of a non-magnetic material of an aluminum alloy, the magnetic lines of force of the permanent magnets 315a incorporated in the rotor core 315 generate no eddy current in the main bearing 120, so that eddy current loss hardly occurs. And high efficiency can be achieved.
[0066]
Further, the motor unit 303 is driven by an inverter, and when the high-speed operation is performed in accordance with the load, the magnetic attraction force increases, and even if the force for tilting the shaft 104 increases, the shaft 104 is connected to the main bearing 120 and the auxiliary bearing. Since the two-sided bearing structure supports both bearings 121, inclination can be prevented, sliding loss can be reduced, high efficiency can be maintained, and one-sided contact due to shaft inclination can be prevented, improving reliability. .
[0067]
Furthermore, the stator 113 has a plurality of radially formed teeth portions 113b on the iron core 113a, and the windings 113d are directly applied to the teeth portions 113b via insulating members 113c, so that the distributed winding is performed. In addition, there is no necessary coil end, and by applying the winding 113d directly to the teeth portion 113b via the insulating member 113c, the overall height of the stator 113 and the rotor 314 can be reduced, and the overall height of the electric compressor can be further reduced. It is possible to suppress. Since the total height of the stator 113 and the rotor 314 is low, it is easy to make the gap size between the stator 113 and the rotor 314 uniform, and as a result, magnetic attraction is hardly generated. Can be avoided.
[0068]
(Embodiment 4)
FIG. 4 is a longitudinal sectional view of the electric compressor according to Embodiment 2 of the present invention.
[0069]
The same components as those in the third embodiment are denoted by the same reference numerals, and detailed description is omitted.
[0070]
In FIG. 4, the motor unit 403 includes a stator 213 in which a winding is wound around a stator core made of laminated electromagnetic steel sheets, and a rotor 414 in which a secondary conductor is provided on a rotor core 415 made of laminated electromagnetic steel sheets. It is a two-pole synchronous motor configured. The rotor core 415 contains a permanent magnet 415a made of, for example, a rare earth magnet such as neodymium, iron, or a boron-based ferromagnetic material. Other configurations are the same as those of the third embodiment.
[0071]
Next, the operation of the electric compressor configured as described above will be described.
[0072]
The electric element starts as an induction motor at the time of starting, and performs the synchronous operation by pulling in the synchronous near the synchronous rotational speed. Here, since the permanent magnet 415a built in the rotor core 415 is made of a material having a strong magnetic force such as a rare earth element, the magnetic force is particularly strong, and an extremely strong magnetic attraction is applied to a portion where the distance between the rotor 414 and the stator 213 is small. Force is generated.
[0073]
However, with the same configuration as in the third embodiment, problems due to strong magnetic attraction can be avoided, and as a result, the high efficiency of the synchronous motor can be effectively utilized, high energy efficiency can be obtained, and the inclination of the shaft can be improved. Can be prevented, and the reliability is improved.
[0074]
【The invention's effect】
As described above, the invention described in claim 1 has an effect that an electric compressor with high efficiency and high reliability can be obtained.
[0075]
Further, the invention according to claim 2 has an effect that an electric compressor with high efficiency and high reliability can be obtained.
[0076]
The invention according to claim 3 has an effect that an electric compressor with higher efficiency can be obtained in addition to the effects of claim 1 and claim 2.
[0077]
The invention described in claim 4 has an effect that, in addition to the effect of any one of claims 1 to 3, an inverter-driven electric compressor with higher efficiency and higher reliability can be obtained. .
[0078]
Further, the invention according to claim 5 has an effect that a more reliable electric compressor can be obtained in addition to the effect of claim 4.
[0079]
According to the invention described in claim 6, in addition to the effect of any one of claims 1 to 3, an effect that a synchronous motor driven electric compressor with higher efficiency and higher reliability can be obtained. Yes.
[Brief description of the drawings]
1 is a longitudinal sectional view of an electric compressor according to a first embodiment of the present invention; FIG. 2 is a longitudinal sectional view of an electric compressor according to a second embodiment of the present invention; FIG. 3 is a third embodiment of the present invention; FIG. 4 is a longitudinal sectional view of an electric compressor according to a fourth embodiment of the present invention. FIG. 5 is a longitudinal sectional view of a conventional electric compressor.
101 Closed container 102, 302 Compression mechanism 103, 203, 303, 403 Electric motor 104 Shaft 117 Eccentric shaft 105, 305 Cylinder block 106, 306 Bore 107 Cylinder 108 Connecting rod 109 Piston 110 Compression chamber 111 Oil supply mechanism 112 Lubricating oil 113, 213 Stator 113a Iron core 113b Teeth portion 113c Insulating member 113d Direct winding 114, 214, 314, 414 Rotor 115, 215, 315, 415 Rotor core 115a, 215a, 315a, 415a Permanent magnet 115b Rotor core Compressor element side end 116 Main shaft 118 Sub shaft 120, 320 Main bearing 121 Sub bearing

Claims (6)

A lubricating oil is stored in the closed container, and an electric element including a stator and a rotor having a permanent magnet incorporated in a rotor iron core, and a compression element driven by the electric element are housed therein, and the compression element is eccentric. A shaft having a sub shaft portion and a main shaft portion provided vertically and coaxially with a shaft portion and the eccentric shaft portion interposed therebetween, a cylinder block having a compression chamber, and an axis of the compression chamber in the cylinder block. A main bearing that is disposed substantially orthogonal to the shaft, supports the main shaft portion of the shaft, includes a compression mechanism side end of the rotor core, and does not intersect with a plane substantially orthogonal to the main shaft axis. An electric compressor comprising: a sub-bearing disposed on the cylinder block to support the sub-shaft portion; a piston reciprocating in the compression chamber; and connecting means for connecting the piston and the eccentric shaft. A lubricating oil is stored in the closed container, and an electric element including a stator and a rotor having a permanent magnet incorporated in a rotor iron core, and a compression element driven by the electric element are housed therein, and the compression element is eccentric. A shaft having a sub shaft portion and a main shaft portion provided vertically and coaxially with a shaft portion and the eccentric shaft portion interposed therebetween, a cylinder block having a compression chamber, and an axis of the compression chamber in the cylinder block. A main bearing disposed substantially orthogonally and supporting the main shaft portion of the shaft, a sub-bearing disposed on the cylinder block and supporting the sub-shaft portion, and a piston reciprocating in the compression chamber; Connecting means for connecting the piston and the eccentric shaft, wherein the rotor is provided with a hollow bore at an end of the rotor core on the compression mechanism side, and the main bearing is non-conductive. When made of magnetic material The electric compressor extending inside the bore of the rotor core. The electric compressor according to claim 1, wherein the permanent magnet incorporated in the rotor core is made of a rare earth. The electric compressor according to any one of claims 1 to 3, wherein the electric compressor is an inverter-driven type that is driven at a plurality of operating frequencies including a rotation speed equal to or higher than a commercial power supply frequency. 5. The electric compressor according to claim 4, wherein the stator has a plurality of radially formed teeth portions on an iron core, and the teeth portions are directly wound through an insulating member. The electric compressor according to any one of claims 1 to 3, wherein the electric element starts as an induction motor at the time of starting, and constitutes a synchronous motor that performs synchronous operation by performing a synchronous pull-in operation near a synchronous rotational speed.

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