JP4742985B2 - Expander-integrated compressor and refrigeration cycle apparatus - Google Patents

Description

  The present invention relates to an expander-integrated compressor having a compression mechanism for compressing fluid and an expansion mechanism for expanding fluid, and a refrigeration cycle apparatus including the same.

  2. Description of the Related Art Conventionally, an expander-integrated compressor in which a compression mechanism and an expansion mechanism are arranged vertically in an airtight container is known (see, for example, Patent Document 1).

  The expander-integrated compressor disclosed in FIG. 5 of Patent Document 1 includes a casing formed of a sealed container, and an expansion mechanism, an electric motor, and a compression mechanism disposed in the casing. The expansion mechanism, the electric motor, and the compression mechanism are arranged in order from the top to the bottom. The rotation shaft of the compression mechanism extends vertically, and the expansion mechanism is connected to the rotation shaft. That is, the rotation shaft of the compression mechanism also serves as the rotation shaft of the expansion mechanism. An oil sump is provided at the bottom of the casing. An oil pump is provided at the lower part of the rotating shaft, and an oil supply passage is formed inside the rotating shaft. In the expander-integrated compressor, the oil pumped up by the oil pump is supplied to the sliding portions of the compression mechanism and the expansion mechanism through the oil supply passage.

The casing is partitioned by a partition wall into a space on the compression mechanism side and a space on the expansion mechanism side. The electric motor is arranged in the compression mechanism side space. The expander-integrated compressor is a so-called high-pressure dome type, and the casing is filled with a high-pressure refrigerant. The space on the compression mechanism side is filled with the compressed refrigerant discharged from the compression mechanism.
Japanese Patent Laying-Open No. 2003-139059 (FIGS. 5 and 6)

  By the way, in the high-pressure dome type expander-integrated compressor, the oil supplied to the compression mechanism returns to the oil reservoir after lubricating the sliding portion of the compression mechanism. Alternatively, after being discharged into the casing together with the discharged refrigerant, it is separated from the refrigerant in the casing and returns to the oil sump. Therefore, the oil in the oil reservoir becomes relatively high temperature. On the other hand, in the expansion mechanism, the expanded refrigerant has a relatively low temperature. Therefore, when hot oil in the oil reservoir is supplied to the expansion mechanism through the oil supply passage, heat moves from the oil toward the refrigerant in the expansion mechanism, and the enthalpy of the refrigerant discharged from the expansion mechanism increases. As a result, there has been a problem that the refrigerating capacity is reduced.

  The present invention has been made in view of such points, and an object of the present invention is to provide an expander-integrated compressor including a compression mechanism and an expansion mechanism, from oil to fluid (refrigerant) in the expansion mechanism. It is in suppressing heat transfer.

  An expander-integrated compressor according to the present invention includes a hermetic container, a partition that partitions the inside of the hermetic container into an upper space and a lower space, a compression mechanism that is disposed in the upper space, and compresses fluid. An expansion mechanism that is disposed in the lower space and expands the fluid; an upper rotation portion that rotates the compression mechanism; and a lower rotation portion that receives a rotational force by the expansion mechanism, and penetrates the partition wall. An upper oil sump is formed on the upper side of the partition, and a lower oil sump is formed on the bottom of the lower space, and the upper part of the lower shaft is above the partition. In the portion, an upper suction mechanism for supplying oil from the upper oil reservoir to the compression mechanism is formed, a supply passage for supplying the oil in the upper oil reservoir to the lower space, and an oil passage through the supply passage. A flow rate change mechanism for changing the flow rate, and It includes those were.

  According to the expander-integrated compressor, the upper oil reservoir on the compression mechanism side and the lower oil reservoir on the expansion mechanism side are formed inside the sealed container. The high-temperature oil used for lubrication of the compression mechanism returns to the upper oil sump, and once stays in the upper oil sump, a part thereof is supplied to the lower oil sump via the supply passage. Therefore, the oil in the lower oil sump is lower in temperature than the oil in the upper oil sump. Here, the oil in the upper oil reservoir is sucked by the upper suction mechanism and supplied to the compression mechanism. On the other hand, the oil in the lower oil reservoir is used for lubrication of the expansion mechanism. Therefore, the oil in the upper oil sump with a relatively high temperature is used in the upper space, and the oil in the lower oil sump with a relatively low temperature is used in the lower space. Therefore, since the oil supplied to the expansion mechanism becomes a relatively low temperature oil, heat transfer from the oil to the refrigerant (fluid) in the expansion mechanism is suppressed. As a result, an increase in the enthalpy of the refrigerant discharged from the expansion mechanism can be suppressed, and the refrigeration capacity can be improved.

  However, if the upper space on the compression mechanism side and the lower space on the expansion mechanism side are completely blocked, there is a risk that an oil amount imbalance occurs between the upper oil reservoir and the lower oil reservoir. However, according to the above-described expander-integrated compressor, since the supply passage for supplying the oil in the upper oil reservoir to the lower space and the flow rate changing mechanism for changing the flow rate of the oil passing through the supply passage are provided. The oil imbalance can be corrected.

  A lower suction mechanism that supplies oil from the lower oil reservoir to the expansion mechanism may be formed at a lower portion of the rotating shaft.

  Thereby, the oil in the upper oil reservoir is sucked by the upper suction mechanism and supplied to the compression mechanism, while the oil in the lower oil reservoir is sucked by the lower suction mechanism and supplied to the expansion mechanism. Therefore, oil can be circulated in each of the upper space and the lower space.

  The compression mechanism is configured to discharge a compressed fluid to the upper space, and the expander-integrated compressor is connected to the suction side of the compression mechanism through the hermetic container. A first discharge pipe connected to the sealed container and having one end opened to the upper space, a second suction pipe passing through the sealed container and connected to the suction side of the expansion mechanism, and the sealed container And a second discharge pipe connected to the discharge side of the expansion mechanism.

  In this type of expander-integrated compressor, the compressed fluid is once discharged from the compression mechanism into the upper space and then flows out of the sealed container through the first discharge pipe. On the other hand, the fluid after expansion flows out of the sealed container from the expansion mechanism through the second discharge pipe without being discharged into the lower space. Therefore, the oil contained in the fluid after compression is easily separated and easily returned to the upper oil sump, but the oil contained in the fluid after expansion is difficult to return to the lower oil sump. Therefore, the oil amount tends to be unbalanced between the upper oil sump and the lower oil sump. However, according to the above-described expander-integrated compressor, the compression mechanism is disposed on the upper side, the expansion mechanism is disposed on the lower side, and the supply passage for supplying the oil in the upper oil reservoir to the lower space is provided. The oil on the compression mechanism side can be supplied to the expansion mechanism side using gravity. Therefore, such an oil amount imbalance can be corrected satisfactorily.

  The partition may be formed with a hole for communicating the upper oil reservoir and the lower space, and the supply passage may be formed by the hole.

  This eliminates the need for a separate member for forming the supply passage, thereby reducing the number of parts.

  However, a pipe that communicates the upper oil reservoir and the lower space may be connected to the sealed container, and the supply passage may be formed by the pipe.

  The flow rate changing mechanism may be a valve provided in the supply passage.

  Note that the flow rate changing mechanism may switch between communication / non-communication of the supply passage, and may increase or decrease the flow rate of oil. The “valve” here includes not only an on-off valve but also a valve (flow rate adjusting valve) capable of adjusting an opening degree. Thus, by providing the valve in the supply passage, the amount of oil supplied from the upper oil reservoir to the lower space can be adjusted with a simple configuration.

  The valve may be a manual valve.

  Accordingly, the amount of oil supplied from the upper oil reservoir to the lower space can be adjusted with a simple configuration.

  The valve may be constituted by a solenoid valve.

  The expander-integrated compressor includes an oil amount detector that detects the amount of oil in the lower oil sump, and a controller that controls opening and closing of the solenoid valve based on the oil amount of the lower oil sump. May be.

  As a result, the amount of oil supplied from the upper oil reservoir to the lower space can be automatically adjusted.

  The valve may be configured by a differential pressure valve that is opened when an internal pressure becomes a predetermined value or less, and the expander-integrated compressor may include a hydraulic pressure supply passage that supplies oil in a lower oil reservoir to the differential pressure valve. Good.

  As a result, the amount of oil supplied from the upper oil reservoir to the lower space can be automatically adjusted.

  The valve may be a float valve that opens when the oil level of the lower oil sump reaches a predetermined lower limit position and closes when the oil level of the lower oil sump reaches a predetermined upper limit position.

  As a result, the amount of oil supplied from the upper oil reservoir to the lower space can be automatically adjusted.

  The refrigeration cycle apparatus according to the present invention is guided by the expander-integrated compressor, a first flow path for guiding fluid compressed by a compression mechanism of the expander-integrated compressor, and the first flow path. A radiator that dissipates the fluid, a second channel that guides the fluid from the radiator to the expansion mechanism of the expander-integrated compressor, a third channel that guides the fluid expanded by the expansion mechanism, and the third An evaporator for evaporating the fluid guided by the flow path, and a fourth flow path for guiding the fluid from the evaporator to the compression mechanism are provided.

  Thereby, a refrigeration cycle apparatus with a high refrigeration capacity can be obtained.

  The type of the fluid is not particularly limited, but for example, the fluid may be carbon dioxide.

  As described above, according to the present invention, in the expander-integrated compressor in which the compression mechanism and the expansion mechanism are accommodated in the hermetic container, the heat transfer from the oil to the fluid in the expansion mechanism can be suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, the expander-integrated compressor 10 according to the present embodiment is mounted on a refrigeration cycle apparatus including a refrigerant circuit 32. The refrigerant circuit 32 includes a radiator 20 and an evaporator 30 in addition to the expander-integrated compressor 10. The refrigerant circuit 32 is filled with carbon dioxide as a refrigerant. However, the refrigerant is not limited to carbon dioxide. Further, the types of the radiator 20 and the evaporator 30 are not limited at all, and they may be formed by a so-called air heat exchanger that exchanges heat between a refrigerant and a gas (for example, air). It may be formed by a liquid-liquid heat exchanger that exchanges heat with water or the like.

  The expander-integrated compressor 10 includes a compression mechanism 50, an expansion mechanism 70, and a casing 91 that covers the compression mechanism 50 and the expansion mechanism 70. The casing 91 includes a suction pipe 51 that sucks refrigerant before compression, a discharge pipe 58 that discharges refrigerant after compression, a suction pipe 68 that sucks refrigerant before expansion, and a discharge pipe that discharges refrigerant after expansion. 66 is connected.

  The suction pipe 51 is connected to the outlet side of the evaporator 30 via the pipe 2. The discharge pipe 58 is connected to the inlet side of the radiator 20 through the pipe 3. The suction pipe 68 is connected to the outlet side of the radiator 20 through the pipe 4. The discharge pipe 66 is connected to the inlet side of the evaporator 30 via the pipe 5.

  As shown in FIG. 2, the casing 91 of the expander-integrated compressor 10 is formed of a vertically long, substantially cylindrical sealed container. A partition wall 64 is provided inside the casing 91. In the present embodiment, the partition wall 64 is disposed at a position about 1/3 from the bottom of the casing 91. By the partition wall 64, the internal space of the casing 91 is partitioned into an upper space 50a and a lower space 70a. The compression mechanism 50 is disposed in the upper space 50a, and the expansion mechanism 70 is disposed in the lower space 70a.

  The compression mechanism 50 of this embodiment is a scroll type compression mechanism. However, the compression mechanism 50 is not limited to the scroll type. The compression mechanism 50 includes a rotary shaft 75, a movable scroll 54 fixed to the rotary shaft 75, and a fixed scroll 53 that meshes with the movable scroll 54. The end plate 52 of the fixed scroll 53 is fixed to the casing 91. The fixed scroll 53 and the movable scroll 54 are arranged so as to face each other vertically. The rotating shaft 75 is rotatably supported by a bearing 57.

  The suction pipe 51 passes through the side portion of the casing 91 and is connected to the suction side of the compression mechanism 50. In the end plate 52, a discharge hole 52a of the compression mechanism 50 is formed. The discharge hole 52a communicates the compression chamber 50c formed between the movable scroll 54 and the fixed scroll 53 and the upper space 50a. The discharge pipe 58 is connected to the upper part of the casing 91 and is opened toward the upper space 50a. An oil separation member 39 is provided inside the discharge pipe 58. For the oil separation member 39, for example, a metal mesh or the like is used.

  An electric motor 60 is provided below the compression mechanism 50 in the upper space 50a. The electric motor 60 includes a stator 62 fixed to the inner wall of the casing 91 and a rotor 61 disposed inside the stator 62. The rotor 61 is fixed to the rotating shaft 75 of the compression mechanism 50.

  An upper oil sump 44 is provided at the bottom of the compression space 50 a, that is, above the partition wall 64. Lubricating oil is stored in the upper oil reservoir 44. An oil pump 76 is provided at the lower end of the rotating shaft 75 of the compression mechanism 50. An oil supply path 63 is formed inside the rotary shaft 75. With this configuration, when the rotating shaft 75 rotates, the oil in the upper oil reservoir 44 is pumped up by the oil pump 76 and supplied to the sliding portion of the compression mechanism 50 through the oil supply passage 63. The oil that has flowed out of the compression mechanism 50 and the oil separated from the refrigerant in the upper space 50a returns to the upper oil reservoir 44 by flowing down or dropping.

  The expansion mechanism 70 of this embodiment is a rotary expansion mechanism. However, the expansion mechanism 70 is not limited to the rotary type. The expansion mechanism 70 includes a cylinder 42, a front head 67, a rear head 69, a rotating shaft 73 having an eccentric rotor 45, and a piston 71.

  The rotation shaft 73 of the expansion mechanism 70 has a smaller outer diameter than the rotation shaft 75 of the compression mechanism 50. The rotating shaft 73 is rotatably supported by a bearing 65 and a bearing 65a. The rotating shaft 73 and the rotating shaft 75 are connected via a joint 74 and are aligned on the same straight line. A lower oil sump 43 is provided at the bottom of the lower space 70a (the bottom of the sealed container 91). An oil pump 72 is provided at the lower end of the rotating shaft 73. An oil supply path 86 is formed inside the rotation shaft 73. With this configuration, when the rotary shaft 73 rotates, the oil in the lower oil reservoir 43 is pumped up by the oil pump 72 and supplied to the sliding portion of the expansion mechanism 70 through the oil supply passage 86.

  A suction pipe 68 and a discharge pipe 66 are connected to the expansion mechanism 70. The suction pipe 68 passes through the side portion of the casing 91 and is connected to the suction side of the expansion mechanism 70. The discharge pipe 66 passes through the side portion of the casing 91 and is connected to the discharge side of the expansion mechanism 70. The upper part of the cylinder 42 is covered with a front head 67, and the lower part of the cylinder 42 is covered with a rear head 69. The piston 71 is disposed in the cylinder 42. An expansion chamber 41 is formed inside the cylinder 42. The suction pipe 68 and the discharge pipe 66 are connected to the expansion chamber 41.

  An oil supply path 47 is formed in the partition wall 64. A manual valve 48 is provided in the oil supply passage 47. The oil supply path 47 supplies the oil in the upper oil reservoir 44 in the upper space 50a to the lower oil reservoir 43 in the lower space 70a. The amount of oil supplied from the upper oil reservoir 44 to the lower oil reservoir 43 can be adjusted by adjusting the opening of the valve 48. In the expander-integrated compressor 10 according to the present embodiment, a part of the oil in the upper oil reservoir 44 can be supplied to the lower oil reservoir 43 through the oil supply passage 47, and the amount of oil in the upper oil reservoir 44 and the lower side can be reduced. The amount of oil in the oil sump 43 can be balanced at a predetermined ratio. The oil supply path 47 and the valve 48 form an oil leveling mechanism 40.

  When the electric motor 60 of the expander-integrated compressor 10 is started, the refrigerant is compressed in the compression mechanism 50, the refrigerant expands in the expansion mechanism 70, and the refrigerant circulates in the refrigerant circuit 32 (see FIG. 1).

  The refrigerant compressed by the compression mechanism 50 is discharged from the expander-integrated compressor 10 through the discharge pipe 58. At this time, most of the oil contained in the refrigerant is separated in the casing 91, but as shown in FIG. 1, a predetermined amount of oil (%) is conveyed to the radiator 20 together with the refrigerant.

  The refrigerant dissipated by the radiator 20 is sucked into the expansion mechanism 70 of the expander-integrated compressor 10 through the suction pipe 68. In the expansion mechanism 70, the high-pressure refrigerant expands, and its internal energy is converted into energy for rotating the rotating shaft 73. The expanded refrigerant becomes a low-pressure two-phase refrigerant and is discharged from the expander-integrated compressor 10 through the discharge pipe 66. At this time, part of the oil supplied to the sliding portion of the expansion mechanism 70 is discharged from the discharge pipe 66 together with the refrigerant. As a result, a predetermined amount x (%) of refrigerant is further discharged from the expansion mechanism 70, and the amount of oil contained in the discharged refrigerant is a + x (%).

  The discharged refrigerant evaporates in the evaporator 30. The evaporated refrigerant is sucked into the compression mechanism 50 of the expander-integrated compressor 10 through the suction pipe 51. The sucked refrigerant is compressed by the compression mechanism 50 and discharged into the upper space 50 a in the casing 91. As described above, the refrigerant once discharged into the upper space 50 a flows out from the casing 91 through the discharge pipe 58. At this time, part of the lubricating oil contained in the refrigerant is separated, and the amount of oil discharged from the discharge pipe 58 is a (%).

  Here, assuming that the upper space 50a and the lower space 70a are completely partitioned and the oil supply path 47 does not exist, a total of x (%) of oil flows out from the lower space 70a and flows into the upper space 50a. Will cause a total of x (%) of oil to flow. Therefore, as it is, the balance between the oil amount in the upper oil sump 44 and the oil amount in the lower oil sump 43 is lost. Further, the oil in the lower oil sump 43 is insufficient, and there is a possibility that the lubrication failure of the expansion mechanism 70 may occur.

  However, in the expander-integrated compressor 10 of the present embodiment, the oil supply passage 47 is formed in the partition wall 64, and oil can be supplied from the upper oil reservoir 44 to the lower oil reservoir 43. Therefore, the unbalance between the oil amount in the upper oil reservoir 44 and the oil amount in the lower oil reservoir 43 can be eliminated. Also, poor lubrication of the expansion mechanism 70 can be prevented.

  As described above, according to the present embodiment, the inside of the casing 91 is partitioned into the upper space 50a and the lower space 70a by the partition wall 64, the upper oil sump 44 is formed in the upper space 50a, and the lower space 70a. A lower oil reservoir 43 is formed. The high-temperature oil used to lubricate the compression mechanism 50 once returns to the upper oil sump 44 and stays in the upper oil sump 44 for a predetermined time, and then a part thereof passes through the oil supply path 47 to lower the lower oil sump 43. To be supplied. Therefore, the oil in the lower oil sump 43 has a lower temperature than the upper oil sump 44.

  An oil pump 76 immersed in the oil in the upper oil reservoir 44 is provided at the lower portion of the rotation shaft 75 of the compression mechanism 50, and the oil in the lower oil reservoir 43 is disposed at the lower portion of the rotation shaft 73 of the expansion mechanism 70. An oil pump 72 is provided. Therefore, the oil in the upper oil reservoir 44 is sucked up by the oil pump 76 on the compression mechanism 50 side and supplied to the compression mechanism 50. On the other hand, the oil in the lower oil reservoir 43 is sucked up by the oil pump 72 on the expansion mechanism 70 side and supplied to the expansion mechanism 70. Thus, according to this embodiment, oil can be circulated in each of the upper space 50a and the lower space 70a. Therefore, the oil in the lower oil reservoir 43 can be made lower in temperature than the upper oil reservoir 44.

  As described above, according to the present embodiment, the oil supplied to the expansion mechanism 70 becomes oil having a relatively low temperature, so that heat transfer from the oil to the refrigerant in the expansion mechanism 70 is suppressed. As a result, an increase in the enthalpy of the refrigerant discharged from the expansion mechanism 70 can be suppressed, and the refrigeration capacity can be improved.

  In the present embodiment, the oil supply path 47 is formed by a hole formed in the partition wall 64. For this reason, a separate member for forming the oil supply path 47 is not particularly required, and the number of parts can be reduced.

  Further, according to the present embodiment, the valve 48 is provided in the oil supply path 47. Therefore, the amount of oil supplied from the upper oil reservoir 44 to the lower oil reservoir 43 can be adjusted.

  In particular, in the present embodiment, since the valve 48 is a manual valve, it is possible to correct the oil amount imbalance with a simple configuration.

(Embodiment 2)
As shown in FIG. 3, the expander-integrated compressor 10 according to the second embodiment is a modification of the configuration of the oil supply path that supplies oil from the upper oil reservoir 44 to the lower oil reservoir 43.

  In the present embodiment, the oil supply path 78 is provided outside the casing 91. The oil supply path 78 of this embodiment is formed by a U-shaped tube, one end of which passes through the side portion of the casing 91 and faces the upper oil reservoir 44, and the other end passes through the side portion of the casing 91 and goes down. It faces the side space 70a. A manual valve 77 is provided in the oil supply path 78.

  In the present embodiment, unlike the first embodiment, no hole 47 (see FIG. 2) is formed in the partition wall 64. Therefore, the partition wall 64 completely separates the upper space 50a and the lower space 70a. Other configurations are the same as those of the first embodiment, and thus the description thereof is omitted.

  Therefore, also in this embodiment, substantially the same effect as that of Embodiment 1 can be obtained.

(Embodiment 3)
As shown in FIG. 4, the expander-integrated compressor 10 according to the third embodiment is obtained by replacing the manual valve 48 provided in the oil supply passage 47 with an electromagnetic valve 79 in the first embodiment. In the present embodiment, the oil level sensor 80 is provided in the lower oil reservoir 43 (that is, the bottom of the casing 91). Further, the present embodiment includes a controller 81 that receives a signal from the oil level sensor 80 and controls the electromagnetic valve 79. The controller 81 performs open / close control to open the electromagnetic valve 79 when the oil level of the lower oil sump 43 is below a predetermined lower limit position and close the electromagnetic valve 79 when the oil level is higher than a predetermined upper limit position. That is, the controller 81 controls the electromagnetic valve 79 so that the amount of oil in the lower oil reservoir 43 falls within a predetermined range.

  Also in this embodiment, substantially the same effect as in the first embodiment can be obtained. Furthermore, according to the present embodiment, oil can be automatically supplied from the upper oil reservoir 44 to the lower oil reservoir 43 so that the amount of oil in the lower oil reservoir 43 is not insufficient. Therefore, poor lubrication in the expansion mechanism 70 can be prevented more reliably.

(Embodiment 4)
As shown in FIG. 5, the expander-integrated compressor 10 according to the fourth embodiment is obtained by replacing the manual valve 77 provided in the oil supply path 78 with a solenoid valve 79 in the second embodiment. Also in this embodiment, the oil level sensor 80 is provided in the lower oil sump 43, and a controller 81 that controls the electromagnetic valve 79 based on a signal from the oil level sensor 80 is provided. As in the third embodiment, the controller 81 controls the electromagnetic valve 79 so that the amount of oil in the lower oil reservoir 43 falls within a predetermined range.

  Therefore, also in this embodiment, the same effect as that of Embodiment 3 can be obtained.

(Embodiment 5)
As shown in FIG. 6, the expander-integrated compressor 10 according to the fifth embodiment is a float-type on-off valve 83 instead of the manual valve 48 that opens and closes the oil supply passage 47 of the partition wall 64 in the first embodiment. Is provided.

  In the present embodiment, a reed valve 85 is provided below the oil supply path 47. A float 84 is connected to the reed valve 85, and the float 84 floats in the oil in the lower oil reservoir 43 or on the oil surface. The reed valve 85 has an urging force in the closing direction. However, when the oil level of the lower oil sump 43 falls below a predetermined lower limit value, the buoyancy acting on the float 84 is reduced, and the reed valve 85 is opened. On the contrary, when the oil level of the lower oil sump 43 becomes equal to or greater than a predetermined upper limit value, the buoyancy acting on the float 84 increases and the reed valve 85 is closed. That is, assuming that gravity acting on the float 84 is G, buoyancy is F, and urging force of the reed valve 85 is S, the oil supply path 47 is closed when G ≦ F + S, and the oil supply path when G> F + S. 47 is opened.

  Therefore, according to the present embodiment, substantially the same effect as that of the first embodiment can be obtained. Further, as in the third embodiment, oil can be automatically supplied from the upper oil reservoir 44 to the lower oil reservoir 43 so that the amount of oil in the lower oil reservoir 43 is not insufficient. Therefore, poor lubrication in the expansion mechanism 70 can be prevented more reliably.

(Embodiment 6)
As shown in FIG. 7, the expander-integrated compressor 10 according to the sixth embodiment is opened and closed by internal pressure instead of the manual valve 48 that opens and closes the oil supply passage 47 of the partition wall 64 in the first embodiment. A differential pressure valve 90 is provided.

  The differential pressure valve 90 is provided in the middle of the oil supply path 47. An oil introduction path 88 is formed inside the partition wall 64. As shown in FIG. 8, the oil introduction path 88 connects an oil supply groove 87 formed on the outer periphery of the rotating shaft 73 and the differential pressure valve 90, and introduces oil from the oil supply groove 87 to the differential pressure valve 90. .

  With such a configuration, a hydraulic pressure corresponding to the amount of oil in the lower oil reservoir 43 is applied to the differential pressure valve 90. The lubricating oil in the oil supply passage 86 of the rotating shaft 73 flows into the oil supply groove 87 through one or more orifices 93. The differential pressure valve 90 is opened when the oil pressure in the oil introduction path 88 becomes equal to or lower than a predetermined lower limit value, and is closed when the hydraulic pressure in the oil introduction path 88 becomes equal to or higher than a predetermined upper limit value. That is, assuming that Fo is a force for closing the differential pressure valve 90 due to hydraulic pressure, and Fs is a biasing force acting on the differential pressure valve 90 (a force for opening the differential pressure valve 90), an oil supply path when Fo> Fs. 47 is closed, and when Fo ≦ Fs, the oil supply path 47 is opened.

  Also in this embodiment, substantially the same effect as in the first embodiment can be obtained. Further, as in the third embodiment, oil can be automatically supplied from the upper oil reservoir 44 to the lower oil reservoir 43 so that the amount of oil in the lower oil reservoir 43 is not insufficient. Therefore, poor lubrication in the expansion mechanism 70 can be prevented more reliably.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and can be implemented in various other forms.

  For example, the position of the oil leveling mechanism 40 is not limited to the position of the above embodiment. The oil leveling mechanism 40 may be provided on or around the partition wall 64. The oil leveling mechanism 40 may be provided in the front head 67 or the like.

  As shown in FIG. 9, the expansion mechanism 70 can be immersed in the oil in the lower oil reservoir 43, and the oil supply path and the oil pump of the rotation shaft on the expansion mechanism 70 side can be omitted.

  As described above, the present invention is useful for an expander-integrated compressor used in, for example, a refrigeration cycle apparatus (including an air conditioner, a water heater, a refrigerator, and the like).

Refrigerant circuit diagram of refrigeration cycle apparatus according to an embodiment 1 is a longitudinal sectional view of an expander-integrated compressor according to Embodiment 1. FIG. Vertical section of expander-integrated compressor according to Embodiment 2 Vertical section of expander-integrated compressor according to Embodiment 3 Vertical sectional view of an expander-integrated compressor according to Embodiment 4 Vertical section of expander-integrated compressor according to Embodiment 5 Vertical section of an expander-integrated compressor according to Embodiment 6 AA line sectional view of FIG. Vertical section of an expander-integrated compressor according to another embodiment

Explanation of symbols

43 Lower oil sump 44 Upper oil sump 47 Oil supply path (supply path)
DESCRIPTION OF SYMBOLS 50 Compression mechanism 50a Upper space 60 Electric motor 63 Oil supply path 64 Partition 70 Expansion mechanism 70a Lower space 72 Oil pump (lower suction mechanism)
73 Rotating shaft (lower rotating part)
74 Oil pump (upper suction mechanism)
75 Rotating shaft (Upper rotating part)
86 Oil supply passage 91 Casing (sealed container)

Claims (13)

A sealed container;
A partition partitioning the inside of the sealed container into an upper space and a lower space;
A compression mechanism disposed in the upper space and compressing a fluid;
An expansion mechanism that is disposed in the lower space and expands the fluid;
An upper rotating portion that rotates the compression mechanism and a lower rotating portion that receives a rotational force by the expansion mechanism, and a rotating shaft that extends vertically through the partition wall,
On the upper side of the partition wall, an upper oil sump is formed,
A lower oil sump is formed at the bottom of the lower space,
An upper suction mechanism that supplies oil from the upper oil reservoir to the compression mechanism is formed in an upper portion of the partition wall on the rotating shaft,
A supply passage for supplying the oil in the upper oil reservoir to the lower space;
An expander-integrated compressor comprising: a flow rate changing mechanism that changes a flow rate of oil passing through the supply passage.   The expander-integrated compressor according to claim 1, wherein a lower suction mechanism that supplies oil from the lower oil reservoir to the expansion mechanism is formed at a lower portion of the rotating shaft. The compression mechanism is configured to discharge a compressed fluid to the upper space,
A first suction pipe passing through the sealed container and connected to the suction side of the compression mechanism;
A first discharge pipe connected to the sealed container and having one end opened to the upper space;
A second suction pipe passing through the sealed container and connected to the suction side of the expansion mechanism;
A second discharge pipe passing through the sealed container and connected to the discharge side of the expansion mechanism;
The expander-integrated compressor according to claim 1 or 2, further comprising: The partition is formed with a hole for communicating the upper oil sump with the lower space,
The expander-integrated compressor according to any one of claims 1 to 3, wherein the supply passage is formed by the hole. A pipe that connects the upper oil reservoir and the lower space is connected to the sealed container,
The expander-integrated compressor according to any one of claims 1 to 3, wherein the supply passage is formed by the pipe.   The expander-integrated compressor according to any one of claims 1 to 5, wherein the flow rate changing mechanism is a valve provided in the supply passage.   The expander-integrated compressor according to claim 6, wherein the valve is a manual valve.   The expander-integrated compressor according to claim 6, wherein the valve is configured by a solenoid valve. An oil amount detector for detecting the amount of oil in the lower oil reservoir;
The expander-integrated compressor according to claim 8, further comprising: a controller that controls opening and closing of the solenoid valve based on an amount of oil in the lower oil reservoir. The valve is constituted by a differential pressure valve that is opened when the internal pressure becomes a predetermined value or less,
The expander-integrated compressor according to claim 6, further comprising a hydraulic pressure supply path for supplying oil in a lower oil reservoir to the differential pressure valve.   The valve is configured by a float valve that opens when the oil level of the lower oil sump reaches a predetermined lower limit position and closes when the oil level of the lower oil sump reaches a predetermined upper limit position. An expander integrated compressor. An expander-integrated compressor according to any one of claims 1 to 11,
A first flow path for guiding a fluid compressed by a compression mechanism of the expander-integrated compressor;
A radiator that dissipates heat from the fluid guided by the first flow path;
A second flow path for guiding fluid from the radiator to the expansion mechanism of the expander-integrated compressor;
A third flow path for guiding the fluid expanded by the expansion mechanism;
An evaporator for evaporating the fluid guided by the third flow path;
A fourth flow path for guiding fluid from the evaporator to the compression mechanism;
A refrigeration cycle apparatus comprising: The refrigeration cycle apparatus according to claim 12, wherein the fluid is carbon dioxide.

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