JP2008150962A - Compressor and air conditioner and water heater - Google Patents

Abstract

A highly reliable compressor with good oil return using a CO ₂ refrigerant that has a low global warming potential and does not destroy ozone.
A compressor using CO ₂ as a refrigerant, the sealed container 1, a rotor 50 mounted in the sealed container 1 and fixed to a rotary shaft 4, and an axial direction of the rotor 50 via an air gap. The axial gap type motor 3 having the stators 60 </ b> A and 60 </ b> B facing each other and the compression mechanism unit 2 mounted in the hermetic container 1 and driven by the motor 3 via the rotating shaft 4 are provided. Between the back yoke 63 of the stators 60A and 60B and the inner wall of the hermetic container 1, a stator outer peripheral passage 63b that communicates the space on both axial sides of the motor 3 is provided. The portion where the stator outer peripheral passage 63b is projected in the axial direction of the rotating shaft 4 is close to or in contact with the coils of the stators 60A and 60B.
[Selection] Figure 1

Description

  The present invention relates to a compressor, an air conditioner, and a water heater.

  In recent years, as a measure for preventing global warming, a movement to convert from a refrigeration cycle using an artificial refrigerant such as chlorofluorocarbon to a refrigeration cycle using a natural refrigerant is increasing as a market demand both in Japan and overseas.

Among these natural refrigerants, CO ₂ refrigerant is ODP (ozone depletion coefficient) = 0, GWP (global warming potential) = 1, and it is not toxic or flammable. Yes.

However, CO ₂ refrigerant is about 3 times more than the value of the HFC refrigerant pressure to obtain the same ejection gas temperature typified by R410A, etc. (about 10 [MPa]) for even high load bearing is increased, The bearing surface pressure also increases.

In general, to obtain good lubrication in the bearing part,
It is necessary to keep the value expressed by the viscosity of the oil x the speed of the shaft ÷ the surface pressure above a certain level.

Therefore, when CO ₂ refrigerant is used as a replacement for HFC refrigerant, etc., it is necessary to use refrigeration oil with higher viscosity than when HFC refrigerant is used under the same conditions of compressor speed and bearing ambient temperature. . For example, in order to obtain the same oil film at 100 ° C. (to obtain good lubricity), it is necessary to have a viscosity about twice that of ether oil and ester oil.

In particular, a refrigerating machine oil that can maintain a high viscosity at a high temperature at which the refrigerating machine oil viscosity generally decreases is essential for a compressor that uses a CO ₂ refrigerant.

  By the way, if the viscosity of the refrigerating machine oil is high, the core length of the core cut is usually long in order to obtain a constant torque just by providing a slight core cut on the outer circumference of the stator yoke, for example, on the extension line of the teeth. Combined with this, the flow resistance becomes high, and the refrigeration oil separated from the refrigerant in the space above the motor does not return to the oil sump under the motor through the core cut, and the oil level of the oil sump decreases and the bearing There is a problem of damage.

In the case of a high-pressure dome compressor, the CO ₂ refrigerant has a high pressure, the density of the gas refrigerant is high, the density difference from the refrigeration oil is reduced, and the buoyancy that pushes up the refrigeration oil is increased.

For this reason, the compressor using the CO ₂ refrigerant needs to reduce the passage resistance for returning the refrigeration oil as compared with the HFC (hydrofluorocarbon) refrigerant. For example, in the case of a conventional distributed winding or concentrated winding motor, it is necessary to provide a large core cut around the back yoke of the stator. However, since the back yoke passes a large amount of magnetic flux, a constant cross-sectional area is required. Therefore, by providing a core cut with a large cross-sectional area, the outer diameter of the stator is substantially reduced, and the rotor diameter must be reduced or the slot area must be reduced. It becomes a small motor.

  On the other hand, Patent Document 1 and Patent Document 2 describe the contents of mounting an axial gap type motor on a compressor. In these Patent Documents 1 and 2, the refrigerant is not specified, but in Patent Document 1, the stator is a motor that is sufficiently smaller (full of gaps) than the cross section of the hermetic container. However, in the case of a stator having a back yoke, particularly in a configuration in which the stator back yoke is fixed to the inner wall of the hermetic container with the back yoke outer diameter, the stator back yoke completely partitions the space above and below the motor (air gap). Don't do it). Therefore, there is a problem that the differential pressure between the upper and lower sides of the motor is increased, and the refrigeration oil that has risen into the upper space of the motor is difficult to return to the lower space of the motor.

Further, in the case of a CO ₂ refrigerant, when a core cut is provided in a radial gap type motor, if the cross-sectional area of the back yoke is ensured, the outer diameter of the portion that effectively acts as the back yoke of the stator is reduced, and the characteristics are deteriorated. .
JP-A-61-185040 JP 2004-52657 A

Accordingly, an object of the present invention is to provide a highly reliable compressor with good oil return and an air conditioner and a water heater using the same, using a CO ₂ refrigerant having a low global warming potential and not destroying ozone. There is.

In order to solve the above problems, the compressor of the present invention is:
A compressor using CO ₂ as a refrigerant,
A sealed container;
An axial gap type motor having a rotor mounted in the sealed container and fixed to a rotating shaft, and a stator facing the rotor in the axial direction via an air gap;
A compression mechanism mounted in the sealed container and driven by the motor via the rotating shaft;
Provided between the back yoke of the stator and the inner wall of the sealed container is a stator outer peripheral passage that communicates the space on both axial sides of the motor,
The portion where the stator outer peripheral passage is projected in the axial direction of the rotating shaft is close to or in contact with the coil of the stator.

According to the compressor having the above configuration, by using the axial gap type motor, the axial length of the core cut that becomes the stator outer peripheral passage of the back yoke of the stator can be shortened, and the flow resistance can be reduced. In addition, the magnetic resistance of the back yoke is extremely increased by the core cut because the magnetic flux passes between the adjacent teeth and the back yoke inside the teeth as compared with the inner rotor type electric motor that detours around the teeth outer periphery. Never do. Therefore, it is possible to provide a stator outer peripheral passage that communicates the spaces on both sides in the axial direction of the motor between the back yoke of the stator and the inner wall of the hermetic container without obstructing the magnetic flux passing through the stator. Further, since the refrigerating machine oil separated in the space above the motor falls through the passage communicating with the space on both sides in the axial direction of the motor and is heated by the coil of the stator, the viscosity is lowered. It is easier to return to the sump. Therefore, a highly reliable compressor with good oil return can be realized using a CO ₂ refrigerant that has a low global warming potential and does not destroy ozone.

  Moreover, in the compressor of one Embodiment, the said motor is arrange | positioned in the area | region in the said airtight container with which the high voltage | pressure refrigerant gas discharged from the said compression mechanism part is satisfy | filled.

In the configuration in which the motor is disposed in the high-pressure region in the closed container filled with the high-pressure refrigerant gas discharged from the compression mechanism section, the CO ₂ refrigerant has a high pressure, the density of the gas refrigerant is high, and the density difference from the refrigerating machine oil Therefore, the buoyancy that pushes up the refrigerating machine oil increases. However, the compressor having such a configuration is particularly effective because the refrigerating machine oil in the upper space of the motor can be easily returned to the oil sump.

  Moreover, in the compressor of one Embodiment, the outer periphery of the said rotor exists in the radial inside rather than the inner periphery of the said stator outer periphery channel | path.

  According to the embodiment, the outer periphery of the rotor is radially inward of the inner periphery of the stator outer peripheral passage, so that the flow resistance of the outer periphery of the rotor is sufficiently ignored as compared with the flow resistance of the stator outer peripheral passage. Can be as small as possible.

  In the compressor of one embodiment, the cross-sectional area of the rotor perpendicular to the axis of the rotor in the space between the outer periphery of the rotor and the inner wall of the sealed container is the cross-sectional area perpendicular to the axis of the back yoke of the stator outer peripheral passage. Greater than cross-sectional area.

  According to the embodiment, the cross-sectional area of the rotor perpendicular to the axis of the rotor in the space between the outer periphery of the rotor and the inner wall of the sealed container is made larger than the cross-sectional area of the axially perpendicular cross-section of the back yoke of the stator outer peripheral passage. Thus, the flow resistance of the outer periphery of the rotor can be made small enough to be ignored as compared with the flow resistance of the stator outer peripheral passage.

  In the compressor according to an embodiment, the stator is press-fitted, shrink-fitted, or welded to the inner wall of the sealed container at the outer periphery of the back yoke.

  According to the above embodiment, the stator back yoke is securely held in the sealed container by press-fitting, shrink-fitting, or welding the stator to the inner wall of the sealed container at the outer periphery of the back yoke. In addition, the back yoke can improve the strength of the sealed container and reduce vibration and noise.

  Moreover, in the compressor of one Embodiment, the said coil of the said stator is concentrated winding.

  According to the embodiment, if the stator coil is a concentrated winding, the stator outer peripheral passage can be provided between the poles of the coil.

  Moreover, in the compressor of one Embodiment, the said coil of the said stator is a distributed winding or a wave winding with which the coil end was piled up in the axial direction.

  According to the above embodiment, if the coil of the stator is a distributed winding or wave winding in which the coil ends are stacked in the axial direction, the magnetomotive force can be made close to a sine wave to reduce vibration and noise. In the case of wave winding, the connection between the coils can be reduced, which is particularly suitable when the number of poles is large. Further, in the case of wave winding, the number of places where the core cuts serving as the stator outer peripheral passages are provided increases, and a larger stator outer peripheral passage can be provided.

  Further, in the compressor according to an embodiment, the stator outer peripheral passage includes an outer side of the coil end provided radially inward of the other coil ends, of the coil ends on the outer peripheral side of the coils overlapped with each other, And it was provided between the coils having the other coil ends.

  According to the embodiment, among the coil ends on the outer circumferential side of the coils that are overlapped with each other, the coil ends are provided outside the coil ends that are provided radially inward of the other coil ends, and the other coil ends are provided. When the refrigerating machine oil passes through the stator outer peripheral passage provided between the coils, since the three sides are surrounded by the coil, the refrigerating machine oil is effectively heated by the coil, and the viscosity can be lowered.

  Moreover, in the compressor of one Embodiment, the said stator outer periphery channel | path is provided along the outermost diameter part of the said coil, or is provided in proximity to the outermost diameter part of the said coil.

  According to the above embodiment, the stator outer peripheral passage is provided along the outermost diameter portion of the coil or provided in the vicinity of the outermost diameter portion of the coil, whereby the refrigerating machine oil is effectively heated by the coil. Thus, the viscosity can be lowered.

  In the air conditioner of the present invention, any one of the above compressors is mounted.

According to the above configuration, a highly reliable air conditioner with good performance can be obtained by using a highly reliable compressor with good oil return using a CO ₂ refrigerant that has a low global warming potential and does not destroy ozone. realizable.

  Moreover, the hot water heater of the present invention is characterized in that any one of the above compressors is mounted.

According to the above configuration, a highly reliable hot water heater with high performance is realized by using a highly reliable compressor with good oil return using a CO ₂ refrigerant that has a low global warming potential and does not destroy ozone. it can.

As is clear from the above, according to the compressor of the present invention, a highly reliable compressor with good oil return can be realized using a CO ₂ refrigerant that has a low global warming potential and does not destroy ozone. .

  Moreover, according to the compressor of one embodiment, in the compressor in which the motor is disposed in the high-pressure region in the hermetic container filled with the high-pressure refrigerant gas discharged from the compression mechanism unit, the refrigerating machine oil in the upper space of the motor Is particularly effective because it makes it easier to return the oil to the sump.

  Further, according to the compressor of one embodiment, the flow resistance of the outer periphery of the rotor is changed to the flow resistance of the stator outer peripheral passage by making the outer periphery of the rotor radially inward from the inner periphery of the stator outer peripheral passage. It can be made small enough to be ignored.

  Further, according to the compressor of one embodiment, the flow path resistance of the outer periphery of the rotor is increased by making the cross-sectional area of the space between the outer periphery of the rotor and the inner wall of the sealed container larger than the cross-sectional area of the stator outer peripheral passage. Can be made sufficiently small to be negligible compared to the flow resistance of the stator outer peripheral passage.

  Further, according to the compressor of the embodiment, the stator is press-fitted, shrink-fitted, or welded to the inner wall of the sealed container at the outer periphery of the back yoke, so that the stator back yoke is sealed with the sealed container. The back yoke can improve the strength of the sealed container and reduce vibration and noise.

  Moreover, according to the compressor of one Embodiment, if the coil of the said stator is concentrated winding, the said stator outer periphery channel | path can be provided between the poles of a coil.

  Further, according to the compressor of one embodiment, if the coil of the stator is a distributed winding or wave winding in which the coil ends are stacked in the axial direction, the magnetomotive force can be brought close to a sine wave to reduce vibration and noise. . Further, in the case of wave winding, the connection between the coils can be reduced, and it is particularly suitable when the number of poles is large. Further, the number of places where a core cut serving as a stator outer peripheral passage is provided increases, and a larger stator outer peripheral passage. Can be provided.

  Moreover, according to the compressor of one embodiment, out of the coil ends on the outer peripheral side of the coils that are overlapped with each other, the outside of the coil end provided radially inward of the other coil ends, and the other When the refrigerating machine oil passes through the stator outer peripheral passage provided between the coils having the coil ends, the three sides are surrounded by the coil, so that the refrigerating machine oil is effectively heated by the coil and the viscosity can be lowered. .

  Further, according to the compressor of one embodiment, the stator outer peripheral passage is provided along the outermost diameter portion of the coil or provided close to the outermost diameter portion of the coil, so that the refrigerating machine oil is supplied by the coil. Effectively heated, the viscosity can be lowered.

  Further, according to the air conditioner of the present invention, an air conditioner having high performance and high reliability can be realized by using the compressor.

  Moreover, according to the water heater of the present invention, a hot water heater having high performance and high reliability can be realized by using the compressor.

  Hereinafter, the compressor, the air conditioner, and the water heater of the present invention will be described in detail with reference to the illustrated embodiments.

[First Embodiment]
FIG. 1 shows a longitudinal sectional view of a rotary compressor according to a first embodiment of the present invention. The rotary compressor of the first embodiment is a high-pressure dome type using a CO ₂ refrigerant.

  As shown in FIG. 1, the compressor according to the first embodiment includes a hermetic container 1, a compression mechanism unit 2 disposed in the hermetic container 1, and in the hermetic container 1 and above the compression mechanism unit 2. And an axial gap type motor 3 that drives the compression mechanism section 2 via a rotating shaft 4. A suction pipe 11 is connected to the lower side of the sealed container 1, while a discharge pipe 12 is connected to the upper side of the sealed container 1. The refrigerant gas supplied from the suction pipe 11 is guided to the suction side of the compression mechanism unit 2.

  Here, the upward direction refers to the upward direction along the central axis of the sealed container 1 regardless of whether the central axis of the sealed container 1 is inclined with respect to the horizontal plane. The rotary compressor is a vertical type having an oil sump at least in the lower part of the motor 3.

  The motor 3 is disposed in a high-pressure region in the sealed container 1 that is filled with a high-pressure refrigerant gas discharged from the compression mechanism unit 2.

  The axial gap type motor 3 includes a disk-shaped rotor 50 fixed to the rotating shaft 4, an upper stator 60B arranged to face the upper side of the rotor 50 in the axial direction via an air gap, The lower stator 60A is disposed on the lower side of the rotor 50 so as to be opposed to each other through an air gap in the axial direction.

  As shown in FIG. 1, the compression mechanism portion 2 includes a cylindrical main body portion 20 and an upper end plate 8 and a lower end plate 9 that are attached to upper and lower opening ends of the main body portion 20. The rotating shaft 4 passes through the upper end plate 8 and the lower end plate 9 and is inserted into the main body 20. The rotating shaft 4 is rotatably supported by a bearing 21 provided on the upper end plate 8 of the compression mechanism unit 2 and a bearing 22 provided on the lower end plate 9 of the compression mechanism unit 2. A crankpin 5 is provided on the rotary shaft 4 in the main body 20, and compression is performed by a compression chamber 7 formed between a piston 6 fitted and driven by the crankpin 5 and a corresponding cylinder. . The piston 6 rotates in an eccentric state or revolves to change the volume of the compression chamber 7.

  FIG. 2 shows an exploded perspective view of the rotor 50 and the lower stator 60A, and FIG. 3 shows a plan view of the lower stator 60A. The upper stator 60B has the same configuration as the lower stator 60A (upside down).

  As shown in FIG. 2, the rotor 50 is formed by superposing four fan-shaped permanent magnets 52 arranged along the circumference so as to be sandwiched between rotor cores 51 from both sides in the axial direction. The rotor core 51 is provided with a circular hole 51a in the center and four slits 51b radially, and the permanent magnets 52 are arranged at predetermined intervals in the circumferential direction between the slits 51b. In the space between the slit 33b of the rotor core 51 and the permanent magnet 52, a gas passage through which the refrigerant gas flows in the axial direction is formed.

  The lower stator 60A includes a disk-shaped back yoke 63 made of a magnetic material having a central hole 63a, and six lower stators that stand from the back yoke 63 toward the rotor 50 and are provided at substantially equal intervals in the circumferential direction. Teeth 64, an axial coil 62 wound around each tooth 64 around a direction parallel to the rotation shaft 4, and a tip of the tooth 64 are provided so as to widen the facing area with respect to the air gap surface. A disk-shaped magnetic plate 61 having a hole 61a. On the other hand, the upper stator 60B has the same configuration as the lower stator 60A except that the upper and lower sides are upside down. The magnetic plates 61 of the upper stator 60B and the lower stator 60A are radially provided with slits 61b for magnetically insulating the plurality of teeth 64 from each other.

  The six teeth 64 are magnetically connected to each other by a back yoke 63, and are connected by a magnetic plate 61 on the side opposite to the back yoke 63 (side facing the rotor). The coil 62 is, for example, a three-phase star connection and supplies current from an inverter.

  A coil 62 is wound around the positions of the upper stator 60B and the lower stator 60A facing the rotor 50 so that opposite polarities are generated. That is, a coil wound in the same direction as viewed from one axial direction is provided.

  The upper stator 60B and the lower stator 60A are disposed on both radial sides of the rotor 50 and are fixed to the hermetic container 1. The rotating shaft 4 transmits the rotational force of the rotor 50 to the compression mechanism unit 2.

  Although the outer peripheral portion of the back yoke 63 is in contact with the inner wall of the sealed container 1, the magnetic plate 61 is separated from the inner wall of the sealed container 1 by a certain distance. This is because the magnetic flux is short-circuited if it comes close to or comes into contact with the inner wall of the sealed container 1.

  As shown in FIGS. 2 and 3, a core cut 63 b is provided on the outer periphery of the back yoke 63 so as to follow the outer shape of the coil 62.

  The core cut 63b of the back yoke 63 is a stator outer peripheral passage that communicates spaces on both axial sides of the motor 3, and can be used effectively as an oil return passage. Here, the core cut is provided between the poles, for example, in the case of concentrated winding. The core cut of the back yoke may be larger or smaller than the outer shape of the coil.

  The rotor 50 is optional, but in the first embodiment, the rotor cores 51 magnetically separated by slits 51b are provided on both sides of the permanent magnet 52 for each magnetic pole. However, since it is difficult to hold the rotor core 51 with the rotary shaft 4 as it is, it is desirable to use a non-magnetic holder that holds the rotor core 51 and the permanent magnet 52.

  The upper stator 60B and the lower stator 60A are sufficient to have a symmetrical shape, but may be different.

  Next, the operation of the rotary compressor will be described.

  As shown in FIG. 1, the refrigerant gas is supplied from the suction pipe 11 to the compression chamber 7 of the compression mechanism unit 2, and the compression mechanism unit 2 is driven by the motor 3 to compress the refrigerant gas. The compressed refrigerant gas is discharged into the sealed container 1 from the discharge hole 23 of the compression mechanism section 2 together with the refrigerating machine oil, is carried to the upper space of the compression mechanism section 2 through the motor 3, and is discharged to the discharge pipe 12. It is discharged to the outside of the sealed container 1 more.

  At this time, the refrigerant gas is guided to the upper space through passages (not shown) provided in the vicinity of the rotation axis of the rotor 50 and the inner periphery of the upper stator 60B and the lower stator 60A. The refrigerating machine oil contained in the refrigerant gas is blown off by the centrifugal force of the rotor 50 and liquefied by adhering to the inside of the sealed container 1 in the form of fine particles, and then the upstream of the refrigerant gas flow of the motor 3 by the action of gravity. Return to the side.

  In the compressor of the first embodiment, the refrigerating machine oil that has lubricated the compression mechanism 2 and the bearing is heated by the coils 62 of the upper stator 60B and the lower stator 60A while passing through the motor 3 to lower the viscosity. Then, the refrigerating machine oil separated in the space above the motor 3 falls through the core cut 63b. Since the refrigeration oil lowers the viscosity, the refrigeration oil is more likely to return to the sump. In particular, the area around the lower stator 60A can be made smaller than the core cut 63b of the upper stator 60B. The refrigerating machine oil that has dropped the core cut 63b of the upper stator 60B and the lower stator 60A is cooled again by passing through the vicinity of the suction pipe 11, recovers the viscosity, and lubricates the bearings 21 and 22 satisfactorily.

Therefore, a highly reliable rotary compressor with good oil return can be realized using a CO ₂ refrigerant that has a low global warming potential and does not destroy ozone.

Further, in the high-pressure dome type rotary compressor, the CO ₂ refrigerant becomes high pressure and the density of the gas refrigerant becomes high, and the density difference between the CO ₂ refrigerant and the refrigerating machine oil becomes small, so that the buoyancy that pushes up the refrigerating machine oil becomes large. However, according to the rotary compressor having the configuration of the first embodiment, the refrigerating machine oil in the upper space of the motor 3 can be easily returned to the oil sump, which is particularly effective.

  Here, the outer periphery of the rotor 50 is radially inward from the inner periphery of the stator outer periphery passage (core cut 63b). Furthermore, the cross-sectional area of the space between the outer periphery of the rotor 50 and the inner wall of the sealed container 1 is larger than the cross-sectional area of the stator outer peripheral passage (core cut 63b). Thereby, the flow resistance of the outer periphery of the rotor 50 can be made small enough to be ignored as compared with the flow resistance of the stator outer peripheral passage.

  Further, the axial length of the back yoke 63 of the upper stator 60B and the lower stator 60A is less than or equal to ½ of the total motor length (the axial length of the rotor 50, the upper stator 60B and the lower stator 60A). This is desirable in that the flow path resistance is ½ or less. In fact, if the teeth 64, the rotor 50, and the back yoke 63 are approximately the same, the axial length of the back yoke 63 is ½ or less of the total motor length.

  The magnetic plates 61 of the upper stator 60B and the lower stator 60A are not essential.

  Further, the passages on the inner peripheral side of the upper stator 60B and the lower stator 60A are for raising the refrigerant containing the refrigeration oil into the upper space of the motor 3, but this passage is also in contact with the coil 62. Then, while cooling the coil 62, the refrigerating machine oil goes up while heating. At this time, a part of the refrigerating machine oil is dropped on the gap surface between the rotor 50 and the upper stator 60 </ b> B, and is scattered on the outer periphery by the centrifugal force of the rotor 50. Therefore, the core cut 63b of the upper stator 60B does not necessarily need to be sufficiently large.

  Further, considering the change in the viscosity of the refrigerating machine oil, the compression mechanism and the bearing are suitable when they are provided in the lower part of the motor.

  Note that the back yoke 63 of the upper stator 60B and the lower stator 60A may be shrink-fitted to the inner periphery of the hermetic container 1 in some cases where the axial length is too short. In this case, the back yoke 63 may be fixed by welding.

  FIG. 4 shows a distributed winding stator structure that can be replaced in the rotary compressor of the first embodiment. The stator 80 is a distributed winding having windings in which coil ends are stacked in the axial direction.

  The stator 80 includes, for example, a stator core 82 attached to the inside of a sealed container (not shown) by press fitting, shrink fitting, or welding, and coils U1, V1, W1, U2, V2, W2 attached to the stator core 82. And have. The stator 80 has a two-layer structure of lower layer coils U2, V2, W2 and upper layer coils U1, V1, W1. The stator core 82 is made of a soft magnetic material, for example, iron having a high magnetic permeability.

  The stator core 82 includes an annular back yoke 83 disposed so as to be substantially orthogonal to the rotation shaft 4, and teeth provided on one surface of the back yoke 83 on the rotor 31 side so as to stand in the axial direction. 24b. Since the stator 80 is press-fitted, shrink-fitted, or welded to the inner wall of the sealed container 1 on the outer periphery of the back yoke 83, the back yoke 83 of the stator 80 can be reliably held in the sealed container 1. At the same time, the strength of the sealed container 1 is improved by the back yoke 83, and vibration and noise can be reduced.

  The teeth 84 extend along the rotation shaft 4 (shown in FIG. 1), and a plurality of teeth 84 are provided around the rotation shaft 4. The coils U1, V1, W1, U2, V2, and W2 are wound around a plurality of teeth 84. Therefore, the coil ends of the coils U1, V1, W1, U2, V2, and W2 have portions that overlap with other coils. One coil U2, V2, W2 of the part where this coil end overlaps is wound on the same plane. Further, the other coils U1, V1, and W1 of the portion where the coil ends overlap are bent in the axial direction and toward the rotor 50 with respect to the teeth 84. Thus, the other coils U1, V1, W1 are wound without interfering with the coil ends of the one coil U2, V2, W2.

  The coils U1, V1, W1, U2, V2, and W2 are arranged in the upper stage with a U phase, a V phase, and a W phase, and the lower stage has a U phase, a V phase, and a W phase at positions that are 180 ° opposite to the upper U phase. Is arranged. The coil ends of the upper coils U1, V1, and W1 are bent inwardly with respect to the teeth 84 from the lower coil ends to avoid interference with the coil ends of the lower coils U2, V2, and W2. Above the coil end and on the inside with respect to the teeth 84.

  The stator outer peripheral passage 85 is a lower coil provided outside the upper coils U1, V1 and W1 which are retracted to the inner peripheral side among the coil ends overlapped with each other, and provided on the outer peripheral side. It is provided between U2, V2, and W2. That is, the stator outer peripheral passage 85 becomes the outer peripheral portion of the tooth 84. When passing through the stator outer peripheral passage 85, the refrigerating machine oil passes through the outer peripheral side of the coil ends of the upper coils U1, V1, and W1 and near the bent portions of the coil ends of the lower coils U2, V2, and W2. To reduce the viscosity. In general, a space for ensuring insulation is provided between the coils U1, V1, W1, U2, V2, W2 and the inner peripheral portion of the sealed container 1, and this portion In addition, a core outer periphery passage may be formed by appropriately providing a core cut.

  FIG. 5 shows a wave-winding stator structure that can be replaced in the compressor of the first embodiment.

  The coils Ud, Vd, Wd of the stator 90 are so-called wave windings. That is, the coils Ud, Vd, Wd that have passed through the slot portions between the teeth 94 are wound in different directions on the outer peripheral side and the inner peripheral side. That is, each phase has one coil regardless of the number of poles. Therefore, even when the number of poles is increased, connection is facilitated and a space for connection is not required.

  The coils Ud, Vd, Wd are referred to as a first layer, a second layer, and a third layer from the bottom. The portions of the coils Ud, Vd, Wd accommodated in the slot portions between the teeth 94 are accommodated over almost the entire length of the teeth and do not overlap with other phases.

  In the first layer, the coil Ud is arranged in a planar shape. However, spaces are provided in the inner periphery and the outer periphery with respect to the teeth 94. Using this space, the coil ends of the other phases are bent.

  In the second layer, the coil Vd is arranged, and the coil end is in the same plane as the inside of the slot in the portion that does not overlap the coil Ud in the first layer, but in the portion that overlaps the coil Ud in the first layer, the rotor side Bends upward (in FIG. 5) and passes through a layer above the coil end of the coil U of the first layer (referred to as “upper stage”).

  In addition, the coil Wd is arranged on the third layer, and the coil end of the coil Wd almost goes up.

  The coils Ud, Vd, and Wd of each phase are wound around a winding frame in advance and shaped into a predetermined shape, and then externally fitted on the teeth 94 of the stator core 92.

  A wave-winding stator 90 shown in FIG. 5 forms a stator outer peripheral passage 95 on the outer periphery of the coil ends of the coils Wd and Vd retracted inward and in the vicinity of the boundary between the coil ends provided on the outer side. That is, the stator outer peripheral passage 95 becomes the outer peripheral portion of the tooth 94.

  The effect of the stator outer peripheral passage is the same in both of the stators 80 and 90 shown in FIGS.

  However, distributed winding and wave winding can bring the magnetomotive force closer to a sine wave and reduce vibration and noise. Further, the wave winding can reduce the connection between the coils, and is particularly suitable when the number of poles is large. Further, in the case of wave winding, the number of places where a core cut (stator outer peripheral passage) is provided increases, and a larger core cut can be provided.

[Second Embodiment]
FIG. 6 shows a longitudinal sectional view of a rotary compressor according to the second embodiment of the present invention. In the compressor according to the second embodiment, the stator and the rotor each have a set of axial gap motors. The rotary compressor is a high-pressure dome type using a CO ₂ refrigerant.

  As shown in FIG. 6, the rotary compressor according to the second embodiment includes a sealed container 101, a compression mechanism unit 102 disposed in the sealed container 101, and the upper side of the compression mechanism unit 102 in the sealed container 101. And an axial gap type motor 103 that drives the compression mechanism 102 via a rotating shaft 104. A suction pipe 111 is connected to the lower side of the sealed container 101, while a discharge pipe 112 is connected to the upper side of the sealed container 101. The refrigerant gas supplied from the suction pipe 111 is guided to the suction side of the compression mechanism unit 102.

  Here, the upward direction refers to the upward direction along the central axis of the sealed container 101 regardless of whether the central axis of the sealed container 101 is inclined with respect to the horizontal plane. The rotary compressor is a vertical type having an oil sump at least at the lower part of the motor 103.

  The axial gap type motor 103 includes a rotor 130 and a stator 140 disposed on the lower side in the axial direction of the rotor 130.

  FIG. 7 shows an exploded perspective view of the motor 103.

  As shown in FIG. 7, the rotor 130 includes a rotor core 131 and four fan-shaped permanent magnets 132 arranged along the circumference below the rotor core 131.

  The stator 140 is wound around the back yoke 143, six teeth 144 that stand from the back yoke 143 toward the rotor 50, and are provided at substantially equal intervals in the circumferential direction, and the six teeth 64. The axial coil 62 is provided. A core cut 146 is provided on the outer periphery of the back yoke 143 and on the radially outer side of each tooth 144. The core cut 146 is used for a refrigerant passage, a wind passage for cooling, and the like. Further, a stress relaxation hole 145 is provided in the fixing portion 147 where the inner periphery of the casing (not shown) contacts the outer periphery of the back yoke 143. By this stress relaxation hole 145, the back yoke 143 is deformed in-plane and is not displaced in the axial direction due to stress during shrink fitting (or press fitting) for fixing the fixing portion 147 of the back yoke 143 to the inner periphery of the casing. The air gap accuracy is improved, and the distortion is relieved around the teeth 144 of the back yoke 143, so that there is no deterioration in magnetic characteristics.

According to the rotary compressor having the above configuration, a highly reliable rotary compressor with good oil return can be realized using a CO ₂ refrigerant that has a low global warming potential and does not destroy ozone.

Further, in the high-pressure dome type rotary compressor, the CO ₂ refrigerant becomes high pressure and the density of the gas refrigerant becomes high, and the density difference between the CO ₂ refrigerant and the refrigerating machine oil becomes small, so that the buoyancy that pushes up the refrigerating machine oil becomes large. However, the rotary compressor having the configuration of the second embodiment is particularly effective because the refrigerating machine oil in the upper space of the motor 103 can be easily returned to the oil sump.

  Here, the outer periphery of the rotor 130 is inside the inner periphery of the stator outer periphery passage (core cut 146). Furthermore, the cross-sectional area of the space between the outer periphery of the rotor 130 and the inner wall of the sealed container 1 is larger than the cross-sectional area of the stator outer peripheral passage (core cut 146). Thereby, the flow resistance of the outer periphery of the rotor 130 can be made small enough to be ignored as compared with the flow resistance of the stator outer peripheral passage.

  The stator 140 is concentrated winding. Further, the stator outer peripheral passage (core cut 146) is provided along the outermost diameter portion of the coil 142 or is provided close to the outermost diameter portion of the coil 142. Normally, the coil 142 needs to be separated from the inner wall of the sealed container 101 to some extent for insulation. The space between the coil 142 and the inner wall of the sealed container 101 is used, and the core cut 146 is continuously provided on the back yoke 143 as it is.

  Further, in the fixing portion 147 fitted to the inner wall of the sealed container 101 of the back yoke 143, a through hole (stress relaxation hole 145) provided in a portion slightly separated from the outer diameter can be used together as a return passage for the refrigerator oil.

[Third Embodiment]
FIG. 8 shows a longitudinal sectional view of a scroll compressor according to the third embodiment of the present invention. The scroll compressor of the third embodiment is a low-pressure dome type, and shows a form in which the compression mechanism 203 is above the motor 202.

  As shown in FIG. 8, the scroll compressor includes an axial gap type motor 202 and a compression mechanism unit 203 driven by the motor 202. Yes. Here, the upper side means the upper side along the central axis of the sealed container 201 regardless of whether or not the central axis of the sealed container 201 is inclined with respect to the horizontal plane.

  The motor 202 is disposed in a low-pressure region in the sealed container 201 that is filled with a low-pressure refrigerant to be sucked into the compression mechanism unit 203. Specifically, the inside of the sealed container 201 is partitioned into a high pressure region H and a low pressure region L with the compression mechanism unit 203 interposed therebetween, and the motor 202 is disposed in the low pressure region L.

  The motor 202 includes a stator 221, a rotor 226 that is disposed below the stator 221 via an air gap in the axial direction, and is fixed to the rotor 226 and uses the rotational force of the rotor 226 to compress the compression mechanism 203. And a rotating shaft 220 for transmitting to the motor.

  The stator 221 includes a stator core 223 attached to the inner surface of the sealed container 201 and a coil 222 attached to the stator core 223.

  The stator core 223 includes an annular back yoke 224a disposed so as to be substantially orthogonal to the rotation shaft 220, and a tooth 224b provided on one surface of the back yoke 224a on the rotor 226 side.

  The back yoke 224a has a boss portion 224c that inserts and holds the rotating shaft 220. The boss portion 224 c is not essential, and the back yoke 224 a may be separated from the rotating shaft 220.

  The teeth 224 b extend along the rotation shaft 220, and a plurality of teeth are provided around the rotation shaft 220. The coil 222 is wound around the axis of each tooth 224b. The coil 222 is excited to generate a magnetic flux in the axial direction of the teeth 224b. The magnetic flux generated in each of the teeth 224b moves to the other teeth 224b via the back yoke 224a.

  In the scroll compressor having the above-described configuration, the refrigerant is introduced from the suction pipe 206, the refrigerant is compressed by the scroll-type compression mechanism unit 203, and the compressed high-pressure refrigerant is discharged from the discharge pipe 207. At this time, the refrigerating machine oil lubricates the bearing portion and the compression mechanism portion 203 from the oil reservoir 208 through the rotation shaft 204 from the lower end of the rotation shaft 204. Then, for example, the refrigerating machine oil separated from the discharged refrigerant in the high pressure space H passes through the oil return passage 234 that connects the high pressure space H filled with the discharged refrigerant and the low pressure space L filled with the sucked refrigerant into the low pressure space L. Return. The refrigerating machine oil is returned to the inside of the sealed container 201 (low pressure portion) through the rotating shaft 204. At that time, a core cut 246 is provided in a portion of the back yoke 224a where there is no coil (between adjacent teeth in the case of concentrated winding). The outer diameter of the rotor 226 is sufficiently smaller than the inside of the sealed container 201. A partition 209 is provided between the oil sump 208 and the rotor 226 to prevent the rotor 226 from splashing the refrigerating machine oil, but an oil passage is also provided in the partition 209.

According to the scroll compressor having the above configuration, it is possible to realize a highly reliable scroll compressor with good oil return using a CO ₂ refrigerant having a small global warming potential and not destroying ozone.

  Here, the outer periphery of the rotor 226 is inside the inner periphery of the stator outer periphery passage (core cut 246). Furthermore, the cross-sectional area of the space between the outer periphery of the rotor 226 and the inner wall of the sealed container 1 is larger than the cross-sectional area of the stator outer peripheral passage (core cut 246). Thereby, the flow resistance of the outer periphery of the rotor 226 is small enough to be negligible compared to the flow resistance of the stator outer peripheral passage.

[Fourth Embodiment]
FIG. 9 shows a circuit diagram of an air conditioner using a compressor according to a fourth embodiment of the present invention. In the air conditioner of the fourth embodiment, any one of the rotary compressors of the first and second embodiments and the scroll compressor of the third embodiment is used.

  As shown in FIG. 9, this air conditioner has a compressor 401, a four-way valve 402 connected to one end of the discharge side of the compressor 401, and one end connected to the other end of the four-way valve 402. The outdoor heat exchanger 403, the electric expansion valve 404 having one end connected to the other end of the outdoor heat exchanger 403, the indoor heat exchanger 405 having one end connected to the other end of the electric expansion valve 404, and An accumulator 406 is connected to the other end of the indoor heat exchanger 405 via a four-way valve 402 and the other end is connected to the suction side of the compressor 401. The compressor 401, the four-way valve 402, the outdoor heat exchanger 403, the electric expansion valve 404, the indoor heat exchanger 405, and the accumulator 406 constitute a refrigerant circuit.

  The air conditioner also includes an outdoor fan 407 disposed in the vicinity of the outdoor heat exchanger 403 and an indoor fan 408 disposed in the vicinity of the indoor heat exchanger 5.

  The compressor 401, the four-way valve 402, the outdoor heat exchanger 403, the electric expansion valve 404, the accumulator 406, and the outdoor fan 407 constitute an outdoor unit 410, and the indoor heat exchanger 405 and the indoor fan 408 constitute the indoor unit 420. It is composed.

According to the air conditioner of the fourth embodiment, by using a highly reliable compressor with good oil return using a CO ₂ refrigerant, the air conditioner is high performance, highly reliable, and friendly to the global environment. Machine can be realized.

[Fifth Embodiment]
FIG. 10 shows a circuit diagram of a heat pump water heater using the compressor of the fifth embodiment of the present invention. In the air conditioner of the fifth embodiment, any one of the rotary compressor of the first and second embodiments or the scroll compressor of the third embodiment is used.

  As shown in FIG. 10, the heat pump water heater includes an outdoor unit 510, an indoor unit 520, and a hot water tank unit 530. The outdoor unit 510 includes a compressor 501, a four-way valve 502 connected to the discharge side of the compressor 501, an outdoor heat exchanger 503 having one end connected to the four-way valve 502, and the outdoor heat exchange. And an electric expansion valve 504 having one end connected to the other end of the container 503. One end of an electric expansion valve 505 as a pressure reducer is connected to the other end of the electric expansion valve 504. Further, the other end of the electric expansion valve 505 of the outdoor unit 510 is connected to one end of the indoor heat exchanger 507 of the indoor unit 520. The other end of the indoor heat exchanger 507 of the indoor unit 520 is connected to the suction side of the compressor 501 via the four-way valve 502 and the accumulator 508 of the outdoor unit 510. In addition, an electromagnetic valve 552 is disposed in the refrigerant pipe 551 between the compressor 501 and the four-way valve 502.

  Further, one end of a hot water supply heat exchanger 531 having a double-pipe structure of the hot water tank unit 530 is connected to the discharge side of the compressor 501 by a refrigerant pipe 553, and an electromagnetic valve 554 is disposed in the refrigerant pipe 553. . The other end of the hot water heat exchanger 531 is connected to a refrigerant pipe between the electric expansion valve 504 and the electric expansion valve 505 via the electric expansion valve 506. The upper end of the inner pipe of the hot water supply heat exchanger 531 is connected to an intermediate position of the hot water supply tank 532, while the lower end of the inner pipe of the hot water supply heat exchanger 531 is connected to the bottom of the hot water supply tank 532. The hot water in the hot water supply tank 532 is circulated by the circulation pump 533 through the inner pipe of the hot water supply heat exchanger 531.

According to the water heater of the fifth embodiment, by using a highly reliable compressor with good oil return using a CO ₂ refrigerant, a high performance, highly reliable heat pump water heater that is friendly to the global environment. Can be realized.

In the first to fifth embodiments, it is essential to compressor refrigerating machine oil capable of maintaining a high viscosity using a CO ₂ refrigerant.

For example, there is a method of using a refrigerating machine oil having a high viscosity at a high temperature even with an ether oil or an ester oil. At the same time, the viscosity of the refrigerating machine oil becomes higher at a low temperature, so that the refrigerating machine oil or CO _{2 at} a low temperature is saturated and dissolved. It is necessary to pay attention to the fluidity of the refrigerating machine oil. When using refrigeration oil with a viscosity index of less than 150, if the viscosity is high at high temperatures, the viscosity will increase excessively at low temperatures, the refrigeration oil will lose its fluidity, the compressor will run out of lubricating oil, and start-up will be poor. Wake up.

  As described above, as a characteristic of the refrigerating machine oil that maintains a high viscosity even at a high temperature and does not lose fluidity even at a low temperature, the viscosity index, which is a measure representing the rate of change in kinematic viscosity with the temperature of the refrigerating machine oil, is 150 or more. About 200 is desirable. In the compressors of the first to third embodiments, PAG (polyalkylene glycol) is used as refrigerating machine oil.

  Although the scroll compressor and the rotary compressor have been described in the first to third embodiments, the present invention may be applied to a compressor having another configuration.

  Moreover, although the said 4th, 5th embodiment demonstrated the air conditioner and heat pump water heater which used the compressor, the structure of an air conditioner and a hot water heater is not restricted to this. The compressor of the present invention is not limited to the fourth and fifth embodiments, and may be applied to other refrigerators and the like.

FIG. 1 is a longitudinal sectional view of a rotary compressor according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of the rotor and the lower stator of the rotary compressor. FIG. 3 is a plan view of a stator of the rotary compressor. FIG. 4 is a diagram showing a distributed winding stator structure that can be replaced in the rotary compressor of the first embodiment. FIG. 5 is a view showing a wave-winding stator structure that can be replaced in the rotary compressor of the first embodiment. FIG. 6 shows a longitudinal sectional view of a rotary compressor according to the second embodiment of the present invention. FIG. 7 is an exploded perspective view of the motor of the compressor. FIG. 8 shows a longitudinal sectional view of a scroll compressor according to the third embodiment of the present invention. FIG. 9 is a circuit diagram of an air conditioner using a compressor according to a fourth embodiment of the present invention. FIG. 10 is a circuit diagram of a heat pump water heater using the compressor of the fifth embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101,201 ... Airtight container 2,102,203 ... Compression mechanism part 3,103,202 ... Motor 4,104,220 ... Rotary shaft 5 ... Crank pin 6 ... Piston 7 ... Compression chamber 8 ... Upper end plate 9 ... Lower end Plate 11, 111 ... Suction pipe 12, 112 ... Discharge pipe 20 ... Main body 21, 22 ... Bearing 50, 130, 226 ... Rotor 51 ... Rotor core 52 ... Permanent magnet 60B ... Upper stator 60A ... Lower stator 61 ... Magnetic plate 62, U1, V1, W1, U2, V2, W2, U2, Vd, Wd, 142, 222 ... Coil 63, 143, 224a ... Back yoke 63b ... Core cut 64, 144, 224b ... Teeth 80, 90, 140, 221 ... Stator 85, 95 ... Stator outer peripheral passage 145 ... Stress relaxation hole 146 ... Core cut 147 ... Fixed portion 223 ... Stator core 224c ... Boss portion 401, 501 ... Compressor

Claims (11)

A compressor using CO ₂ as a refrigerant,
An airtight container (1, 101, 201);
The rotor (50, 130, 226) mounted in the hermetic container (1, 101, 201) and fixed to the rotating shaft (4, 104, 220) and the rotor (50, 130, 226) in the axial direction An axial gap type motor (3, 103, 202) having stators (60A, 60B, 80, 90, 140, 221) opposed via an air gap;
A compression mechanism (2, 102, 203) mounted in the sealed container (1, 101, 201) and driven by the motor (3, 103, 202) via the rotating shaft (4, 104, 220). )
Between the back yoke (63, 83, 93, 143, 224a) of the stator (60A, 60B, 80, 90, 140, 221) and the inner wall of the sealed container (1, 101, 201), the motor ( 3, 103, 202) provided with stator outer peripheral passages (63b, 85, 95, 146, 246) communicating with spaces on both sides in the axial direction,
The portion of the stator outer peripheral passage (63b, 85, 95, 146, 246) projected in the axial direction of the rotating shaft (4, 104, 220) is the stator (60A, 60B, 80, 90, 140, 221). The compressor (62, U1, V1, W1, U2, V2, W2, Ud, Vd, Wd, 142, 222) of the compressor. The compressor according to claim 1,
The motor (3, 103) is arranged in a region in the sealed container (1, 101) that is filled with the high-pressure refrigerant gas discharged from the compression mechanism (2, 102). Compressor. The compressor according to claim 1 or 2,
The compressor characterized in that the outer periphery of the rotor (50) is radially inward from the inner periphery of the stator outer peripheral passage (63b, 85, 95, 146, 246). The compressor according to claim 1 or 2,
The cross-sectional area of the rotor (50, 130, 226) perpendicular to the axis in the space between the outer periphery of the rotor (50, 130, 226) and the inner wall of the sealed container (1, 101, 201) is the stator. The compressor characterized by being larger than the cross-sectional area of the cross section perpendicular to the axis of the back yoke (63, 83, 93, 143, 224a) of the outer peripheral passage (63b, 85, 95, 146, 246). The compressor according to any one of claims 1 to 4,
The stator (60A, 60B, 80, 90, 140, 221) is press-fitted into the inner wall of the sealed container (1, 101, 201) at the outer periphery of the back yoke (63, 83, 93, 143, 224a). A compressor characterized by being shrink-fitted or welded. The compressor according to any one of claims 1 to 5,
The compressor characterized in that the coils (62, 142, 222) of the stator (60A, 60B, 140, 221) are concentrated winding. The compressor according to any one of claims 1 to 5,
The coils (U1, V1, W1, U2, V2, W2, Ud, Vd, Wd) of the stator (80, 90) are distributed windings or wave windings in which coil ends are axially stacked. Compressor. The compressor according to claim 7, wherein
The stator outer peripheral passage (95) is formed on the outer side of the coil (Ud, Vd, Wd) on the outer peripheral side where the coils (Ud, Vd, Wd) are overlapped with each other. And a compressor provided between the coils having the other coil ends. The compressor according to any one of claims 1 to 5,
The stator outer peripheral passages (63b, 85, 95, 146, 246) are formed on the outermost diameter portion of the coils (62, U1, V1, W1, U2, V2, W2, Ud, Vd, Wd, 142, 222). Or provided close to the outermost diameter portion of the coil (62, U1, V1, W1, U2, V2, W2, Ud, Vd, Wd, 142, 222). Compressor characterized by.   An air conditioner equipped with the compressor according to any one of claims 1 to 9.   A water heater equipped with the compressor according to any one of claims 1 to 9.

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