JP5905005B2 - Multi-cylinder rotary compressor and refrigeration cycle apparatus - Google Patents

Description

  Embodiments described herein relate generally to a multi-cylinder rotary compressor and a refrigeration cycle apparatus using the multi-cylinder rotary compressor.

  A multi-cylinder rotary compressor that compresses gas refrigerant circulating in the refrigeration cycle apparatus in multiple stages is known to have a structure in which an electric motor section, a low-stage compression mechanism section, and a high-stage compression mechanism section are housed in a sealed case (See JP 2010-90820 A).

  In this multi-cylinder rotary compressor, an electric motor portion is arranged at an intermediate position in the vertical direction. A high-stage compression mechanism section is disposed below the motor section with the motor section as a center, and a low-stage compression mechanism section is disposed above the motor section. The upper side of the sealed case where the low-stage compression mechanism is located is an intermediate-pressure space that accommodates an intermediate-pressure gas refrigerant compressed by the low-stage compression mechanism. On the other hand, in the sealed case, the lower side where the high-stage compression mechanism section is located and the position of the electric motor section are a high-pressure space that accommodates the high-pressure gas refrigerant compressed by the high-stage compression mechanism section.

  In this multi-cylinder rotary compressor, the low-pressure gas refrigerant is sucked into the low-stage compression mechanism, and is compressed into the intermediate-pressure gas refrigerant by the low-stage compression mechanism, and the intermediate-pressure gas refrigerant is intermediate It is discharged into the pressure space. The intermediate-pressure gas refrigerant discharged into the intermediate-pressure space is sucked into the high-stage compression mechanism through the pipe, and is compressed into a high-pressure gas refrigerant by the high-stage compression mechanism. This high-pressure gas refrigerant is discharged into the high-pressure space. The high-pressure gas refrigerant discharged into the high-pressure space is discharged out of the sealed case from a discharge pipe connected to the high-pressure space.

  Thus, the electric motor part is located in the high-pressure space, and the electric motor part is exposed to the high-pressure gas refrigerant in the high-pressure space.

JP 2010-90820 A

  However, the high-pressure gas refrigerant discharged into the high-pressure space has a high pressure and a high temperature. For this reason, even if the motor part is exposed to the gas refrigerant in the high-pressure space, it cannot be expected that the motor part is cooled by the gas refrigerant. For this reason, it may lead to performance degradation and reliability degradation due to overheating of the electric motor section.

  An object of an embodiment of the present invention is to provide a multi-cylinder rotary compressor in which an electric motor part and a high-stage compression mechanism part and a low-stage compression mechanism part arranged above and below the electric motor part are housed in a sealed case. A multi-cylinder rotary compressor capable of cooling an electric motor unit with an intermediate-pressure working fluid compressed by a low-stage compression mechanism unit, and a refrigeration cycle apparatus using the multi-cylinder rotary compressor Is to provide.

  In order to achieve the above object, according to the multi-cylinder rotary compressor of the embodiment, a sealed case, an electric motor part accommodated in the hermetic case, and positioned below the electric motor part and accommodated in the hermetic case. A low-stage compression mechanism that is driven by the motor unit to compress the low-pressure working fluid to an intermediate pressure and discharges the compressed intermediate-pressure working fluid into the sealed case; and a sealed case located above the motor unit A high-stage compression mechanism that compresses the intermediate-pressure working fluid discharged from the low-stage compression mechanism by being driven by an electric motor unit into a high-pressure working fluid, and provided outside the sealed case. It has an intermediate pressure pipe that leads the intermediate pressure working fluid in the sealed case to the suction side of the high-stage compression mechanism, and a branch pipe that connects the intermediate pressure pipe and the inside of the sealed case. The position of the communication part that communicates with the case is the motor. More an upper position of the communication portion to the branch pipe and the sealed case are communicated with each other is lower than the rotor of the electric motor unit.

Drawing 1 is a mimetic diagram showing the refrigerating cycle of the air harmony machine in the embodiment which is a refrigerating cycle device. FIG. 2 is a longitudinal sectional view of the multi-cylinder rotary compressor of the first embodiment. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a longitudinal sectional view of the multi-cylinder rotary compressor of the second embodiment. 5 is a cross-sectional view taken along line BB in FIG. FIG. 6 is a longitudinal sectional view of the multi-cylinder rotary compressor of the third embodiment. 7 is a cross-sectional view taken along the line CC in FIG.

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

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. Drawing 1 is a mimetic diagram showing the refrigerating cycle of air harmony machine 1 in the embodiment which is a refrigerating cycle device.

  An air conditioner 1 that is a refrigeration cycle apparatus includes a multi-cylinder rotary compressor 2 (represented as “CP” in FIG. 1), an oil separator 3, a four-way valve 4, an outdoor heat exchanger 5, The expansion device 6, the indoor heat exchanger 7, and the accumulator 8 are continuously connected in a cycle shape. Here, the outdoor heat exchanger 5 is a heat source side heat exchanger that functions as a condenser during the cooling operation and also functions as an evaporator during the heating operation. The indoor heat exchanger 7 is a utilization side heat exchanger that functions as an evaporator during cooling operation and as a condenser during heating operation.

  In the air conditioner 1, during the cooling operation, a high-pressure gas refrigerant that is a working fluid is discharged from the multi-cylinder rotary compressor 2 and flows as indicated by solid line arrows shown in FIG. The high-pressure gas refrigerant flows into the outdoor heat exchanger (condenser) 5 through the oil separator 3 and the four-way valve 4, and is condensed by exchanging heat with the outside air in the outdoor heat exchanger 5. The condensed refrigerant flows into the indoor heat exchanger (evaporator) 7 via the expansion device 6, evaporates by exchanging heat with the indoor air in the indoor heat exchanger 7, and cools the indoor air. The evaporated gas refrigerant is sucked into the multi-cylinder rotary compressor 2 via the four-way valve 4 and the accumulator 8.

  On the other hand, at the time of heating operation, high-pressure gas refrigerant is discharged from the multi-cylinder rotary compressor 2 and flows as shown by the broken-line arrows shown in FIG. The high-pressure gas refrigerant flows into the indoor heat exchanger (condenser) 7 through the oil separator 3 and the four-way valve 4, and is condensed by exchanging heat with the indoor air in the indoor heat exchanger 7. Heat the room air. The condensed refrigerant flows into the outdoor heat exchanger (evaporator) 5 through the expansion device 6 and evaporates by exchanging heat with outdoor air in the outdoor heat exchanger 5. The evaporated gas refrigerant is sucked into the multi-cylinder rotary compressor 2 via the four-way valve 4 and the accumulator 8.

  By continuing the circulation of the refrigerant as described above, the cooling operation or the heating operation of the air conditioner 1 is continued.

  The multi-cylinder rotary compressor 2 is a device that compresses the gas refrigerant circulating in the refrigeration cycle in two stages. FIG. 2 is a longitudinal sectional view of the multi-cylinder rotary compressor 2 of the first embodiment. As shown in FIG. 2, the multi-cylinder rotary compressor 2 includes a cylindrical sealed case 9 that is disposed in a vertically long direction in the vertical direction and is formed in an airtight state. In the sealed case 9, an electric motor unit 10, a low-stage compression mechanism unit 11, and a high-stage compression mechanism unit 12 are accommodated.

  The low-stage compression mechanism unit 11 is disposed below the electric motor unit 10, and the high-stage compression mechanism unit 12 is disposed above the electric motor unit 10. In the sealed case 9, lubricating oil that lubricates the sliding portions and the bearing portions of the low-stage compression mechanism section 11 and the high-stage compression mechanism section 12 is stored.

  The electric motor unit 10 includes a stator 13 and a rotor 14. The stator 13 is fixed by being attached to the inner periphery of the sealed case 9 by adhesion or pressure, and the rotor 14 is rotatably inserted inside the stator 13. Drive shafts 15 and 16 are fixed to the central portion of the rotor 14. One drive shaft 15 extends downward, and a low-stage compression mechanism 11 is connected to the tip side thereof. The other drive shaft 16 extends upward, and a high-stage compression mechanism 12 is connected to the tip end side thereof. The drive shaft 15 is formed with two eccentric portions 17, 17 that protrude eccentrically with respect to the axis of the drive shaft 15 and have a phase of 180 ° along the rotation direction of the drive shaft 15. Similarly, the drive shaft 16 is also formed with two eccentric portions 18, 18 that are eccentrically projected with respect to the axis of the drive shaft 16 and have a phase of 180 ° along the rotation direction of the drive shaft 16. .

  The low-stage compression mechanism unit 11 is a mechanism that compresses a low-pressure gas refrigerant into an intermediate-pressure gas refrigerant, and includes two compression units 19 and 20. Each of the two compression parts 19 and 20 includes a cylinder 22, a roller 23, a blade 24, and a spring 25. The cylinder 22 includes a cylinder chamber 21 inside. The roller 23 is accommodated in the cylinder chamber 21 so as to be eccentrically rotatable while a part of the outer peripheral surface is in contact with the inner peripheral surface of the cylinder chamber 21. The blade 24 is provided so as to be able to appear and retract in the cylinder 22, and its tip is brought into contact with the outer peripheral surface of the roller 23 to bisect the inside of the cylinder chamber 21 along the rotation direction of the roller 23. The spring 25 presses the blade 24 in the direction in which the tip of the blade 24 comes into contact with the outer peripheral surface of the roller 23.

  The drive shaft 15 is disposed so as to penetrate the two cylinder chambers 21. Further, eccentric parts 17 and 17 formed on the drive shaft 15 are located in the cylinder chamber 21, and a roller 23 is fitted to these eccentric parts 17. By fitting the roller 23 to the eccentric parts 17, 17, the roller 23 rotates eccentrically in the cylinder chamber 21 as the drive shaft 15 rotates.

  A partition plate 26 is disposed between the two compression portions 19 and 20, and one end face of each cylinder 22 is closed by the partition plate 26. The other end face of each cylinder 22 is closed by a bearing 27 that rotatably supports the drive shaft 15.

  The cylinder chambers 21 of the two compression units 19 and 20 are connected to the accumulator 8 by supply pipes 28. A low-pressure gas refrigerant flows into the accumulator 8, and the liquid refrigerant is removed from the low-pressure gas refrigerant in the accumulator 8. Thereafter, the low-pressure gas refrigerant is sucked into the cylinder chamber 21 through the supply pipe 28 and is compressed in the cylinder chamber 21 to be an intermediate-pressure gas refrigerant. A discharge muffler 29 is provided on the outer surface of the low-stage compression mechanism 11. An intermediate pressure gas refrigerant compressed in the cylinder chamber 21 is discharged to the discharge muffler 29. A discharge gap 30 is formed between the discharge muffler 29 and the upper bearing 27. The intermediate-pressure gas refrigerant discharged from the cylinder chamber 21 into the discharge muffler 29 is further discharged to the internal space 9 a of the sealed case 9 through the discharge gap 30. Thereby, the internal space 9a is filled with the intermediate-pressure gas refrigerant.

  The high-stage compression mechanism 12 is a mechanism that further compresses the intermediate-pressure gas refrigerant compressed by the low-stage compression mechanism 11 into a high-pressure gas refrigerant, and has two compression parts 31 and 32. ing. The two compression parts 31 and 32 each include a cylinder 34, a roller 35, and a blade 36. The cylinder 34 includes a cylinder chamber 33 inside. The roller 35 is accommodated in the cylinder chamber 33 in a state where eccentric rotation is possible while a part of the outer peripheral surface is in contact with the inner peripheral surface of the cylinder chamber 33. The blade 36 is provided so as to be capable of appearing and retracting in the cylinder 34, and the tip of the blade 36 is brought into contact with the outer peripheral surface of the roller 35 to bisect the inside of the cylinder chamber 33 along the rotation direction of the roller 35. On the back side of the blade 36, a blade back chamber 37 isolated from the internal space 9a of the sealed case 9 is provided. The blade back chamber 37 is supplied with the high-pressure lubricating oil separated by the oil separator 3, and the pressure of the lubricating oil presses the tip of the blade 36 in a direction in contact with the outer peripheral surface of the roller 35.

  The drive shaft 16 is disposed so as to penetrate the two cylinder chambers 33. Further, eccentric portions 18 and 18 formed on the drive shaft 16 are located in the cylinder chamber 33, and a roller 35 is fitted to these eccentric portions 18. By fitting the roller 35 to the eccentric portion 18, the roller 35 rotates eccentrically in the cylinder chamber 33 as the drive shaft 16 rotates.

  A partition plate 38 is disposed between the two compression portions 31 and 32, and one end surface of each cylinder 34 is closed by the partition plate 38. The other end face of each cylinder 34 is closed by a bearing 39 that rotatably supports the drive shaft 16.

  An intermediate pressure pipe 40 that guides an intermediate-pressure gas refrigerant in the internal space 9 a of the sealed case 9 to the suction side of the high-stage compression mechanism 12 is provided outside the sealed case 9. The position of the connection portion 41 where the intermediate pressure pipe 40 and the sealed case 9 are connected is above the motor portion 10.

  One end of the branch pipe 42 is connected in the middle of the intermediate pressure pipe 40, and the other end of the branch pipe 42 is connected to the sealed case 9. The position of the connecting portion 43 where the branch pipe 42 and the sealed case 9 are connected is lower than the rotor 14 of the electric motor portion 10.

  A discharge pipe 44 is provided on the discharge side of the high-stage compression mechanism 12, and the discharge pipe 44 is connected to the oil separator 3. The oil separator 3 is a mechanism that separates the lubricating oil contained in the high-pressure gas refrigerant compressed by the high-stage compression mechanism unit 12. The high-pressure gas refrigerant from which the lubricating oil has been separated by the oil separator 3 is supplied to a place that requires the gas refrigerant, for example, the outdoor heat exchanger 5 of the air conditioner 1. One end of the lubricating oil supply path 46 is connected to the bottom of the oil separator 3, and the other end of the lubricating oil supply path 46 is connected to the lubricating oil supply port 47 of the high-stage compression mechanism section 12. The position of the connecting portion 48 where the lubricating oil supply path 46 and the oil separator 3 are connected is below the lubricating oil supply port 47 where the lubricating oil supply path 46 is connected in the high-stage compression mechanism 12. .

  FIG. 3 is a cross-sectional view taken along line AA in FIG. 2 and shows the positional relationship among the sealed case 9, the accumulator 8, and the oil separator 3. As shown in FIG. 3, the connection position between the supply pipe 28 and the low-stage compression mechanism section 11 and the connection position between the intermediate pressure pipe 40 and the high-stage compression mechanism section 12 are determined by the drive shaft 16 of the motor section 10. (And the drive shaft 15) are different positions along the rotation direction. Here, the supply pipe 28 is connected to the low-stage compression mechanism section 11, whereby low-pressure gas refrigerant is sucked into the low-stage compression mechanism section 11. A connection position between the supply pipe 28 and the low-stage compression mechanism 11 is a first suction position 49. In addition, the intermediate pressure pipe 40 is connected to the high-stage compression mechanism section 12, whereby high-pressure gas refrigerant is sucked into the high-stage compression mechanism section 12. The connection position between the intermediate pressure pipe 40 and the high stage compression mechanism 12 is the second suction position 50.

  In such a configuration, when the multi-cylinder rotary compressor 2 is operated, the motor unit 10 is driven and the drive shafts 15 and 16 are rotated. At the same time, the rollers 23 and 35 fitted to the eccentric parts 17 and 18 of the drive shafts 15 and 16 are inside the cylinder chamber 21 of the low stage side compression mechanism part 11 and inside the cylinder chamber 33 of the high stage side compression mechanism part 12. It rotates eccentrically and compresses the gas refrigerant.

  The flow of the gas refrigerant compressed by the low stage compression mechanism unit 11 and the high stage compression mechanism unit 12 will be described below.

  As the roller 23 rotates eccentrically in the cylinder chamber 21 of the low-stage compression mechanism 11, low-pressure gas refrigerant is sucked into the cylinder chamber 21 from the accumulator 8 via the supply pipe 28. The low-pressure gas refrigerant sucked into the cylinder chamber 21 is compressed in the cylinder chamber 21 to become an intermediate-pressure gas refrigerant. The gas refrigerant that has become an intermediate pressure by being compressed in the cylinder chamber 21 is discharged from the cylinder chamber 21 into the discharge muffler 29. The intermediate-pressure gas refrigerant discharged into the discharge muffler 29 is discharged through the discharge gap 30 into the internal space 9 a of the sealed case 9. Thereby, the internal space 9a is filled with the intermediate-pressure gas refrigerant.

  The intermediate-pressure gas refrigerant in the internal space 9 a of the sealed case 9 is sucked into the cylinder chamber 33 of the high-stage compression mechanism 12 through the intermediate-pressure pipe 40. The intermediate-pressure gas refrigerant sucked into the cylinder chamber 33 of the high-stage compression mechanism 12 is compressed by rotating the roller 35 eccentrically in the cylinder chamber 33 to become a high-pressure gas refrigerant. The gas refrigerant that has become high pressure by being compressed in the cylinder chamber 33 is discharged out of the sealed case 9 via the discharge pipe 44 and flows into the oil separator 3. The high-pressure gas refrigerant that has flowed into the oil separator 3 is separated from the lubricating oil contained in the gas refrigerant. The high-pressure gas refrigerant from which the lubricating oil has been separated is supplied to a place that requires the gas refrigerant, for example, the outdoor heat exchanger 5 of the air conditioner 1. The lubricating oil separated by the oil separator 3 is supplied from the lubricating oil supply port 47 to the blade back chamber 37 and the sliding portion of the high-stage compression mechanism 12 through the lubricating oil supply passage 46. .

  Here, the connection part 41 to which the intermediate pressure pipe 40 and the sealed case 9 are connected is located above the motor part 10. For this reason, the intermediate-pressure gas refrigerant discharged from the discharge gap 30 of the discharge muffler 29 into the internal space 9 a of the sealed case 9 passes through the motor unit 10 and reaches the connection unit 41 positioned above the motor unit 10. Then, it flows into the intermediate pressure pipe 40 from the connecting portion 41.

  As described above, the motor unit 10, the low-stage compression mechanism unit 11 positioned below the motor unit 10, and the high-stage compression mechanism unit 12 positioned above the motor unit 10 are accommodated in the sealed case 9. The intermediate pressure pipe 40 that guides the intermediate pressure working fluid discharged from the low-stage compression mechanism 11 into the sealed case 9 to the suction side of the high-stage compression mechanism 12 is connected to the sealed case 9. The position of the portion 41 is above the electric motor portion 10. Therefore, the electric motor unit 10 can be cooled by the intermediate pressure working fluid, and the electric motor unit 10 can be prevented from being overheated.

  Further, when the intermediate-pressure gas refrigerant passes through the electric motor unit 10, the lubricating oil contained in the gas refrigerant adheres to the electric motor unit 10. That is, when the intermediate-pressure gas refrigerant flows into the intermediate-pressure pipe 40, the lubricating oil contained in the intermediate-pressure gas refrigerant decreases. Therefore, the inflow of lubricating oil into the cylinder chamber 33 of the high-stage compression mechanism 12 to which the intermediate pressure pipe 40 is connected can be suppressed.

  Next, when the lubricating oil supplied from the oil separator 3 to the high-stage compression mechanism 12 through the lubricating oil supply passage 46 during operation of the multi-cylinder rotary compressor 2 returns into the sealed case 9. Furthermore, the oil level of the lubricating oil in the sealed case 9 may rise.

  When the oil level of the lubricating oil in the sealed case 9 rises and the oil level reaches the position of the connecting portion 43 where the branch pipe 42 and the sealed case 9 are connected, the lubricating oil passes through the branch pipe 42. It flows into the intermediate pressure pipe 40. Then, the high pressure side compression mechanism 12 is sucked together with the intermediate pressure gas refrigerant flowing in the intermediate pressure pipe 40. For this reason, the liquid level of the lubricating oil in the sealed case 9 does not rise above the position of the connecting portion 43. And since the position of this connection part 43 is below the rotor 14 of the electric motor part 10, it does not occur that the rotor 14 of the electric motor part 10 is immersed in the lubricating oil in the sealed case 9. Accordingly, it is possible to prevent the occurrence of a situation in which the rotational resistance increases due to the rotor 14 being immersed in the lubricating oil and the performance of the multi-cylinder rotary compressor 2 is deteriorated.

  Further, the position of the connecting portion 43 of the branch pipe 42 is above the cylinder chamber 21 of the low-stage compression mechanism portion 11. For this reason, when sufficient lubricating oil exists in the sealed case 9, the periphery of the cylinder chamber 21 is always filled with the lubricating oil. Therefore, the lubricating oil can be easily supplied to the sliding portion in the cylinder chamber 21 and the seal portion of the cylinder chamber 21 by the differential pressure inside and outside the cylinder chamber 21. Thereby, the performance and reliability of the multi-cylinder rotary compressor 2 can be improved.

  Next, the position of the connecting portion 48 between the lubricating oil supply passage 46 and the oil separator 3 in the lubricating oil supply passage 46 for supplying the lubricating oil from the oil separator 3 to the high-stage compression mechanism 12 is determined by the lubricating oil supply passage. 46 and below the lubricating oil supply port 47 to which the high-stage compression mechanism 12 is connected. For this reason, when the operation of the multi-cylinder rotary compressor 2 is stopped, all the lubricating oil in the oil separator 3 passes through the lubricating oil supply path 46 and the high stage side compression mechanism section 12 by the action of gravity. It is possible to prevent returning to the inside of the sealed case 9. As a result, when the multi-cylinder rotary compressor 2 is started, it is possible to prevent the occurrence of a situation in which the sliding portion and the bearing portion of the high-stage compression mechanism portion 12 are damaged due to lack of lubricating oil. The performance and reliability of the compressor 2 can be improved.

  As shown in FIG. 3, the connection position between the supply pipe 28 and the low-stage compression mechanism section 11 and the connection position between the intermediate pressure pipe 40 and the high-stage compression mechanism section 12 are determined by the drive shaft 16 of the motor section 10. (And the drive shaft 15) are different positions along the rotation direction. For this reason, the installation of the intermediate pressure pipe 40 and the installation of the accumulator 8 can be performed without interfering with each other, and the highly productive multi-cylinder rotary compressor 2 can be obtained.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIGS. In the present embodiment and other embodiments described below, the same components as those of the previously described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

  The basic configuration of the multi-cylinder rotary compressor 2A of the second embodiment is the same as that of the multi-cylinder rotary compressor 2 of the first embodiment. The difference between the multi-cylinder rotary compressor 2A of the second embodiment and the multi-cylinder rotary compressor 2 of the first embodiment is the configuration of the low-stage compression mechanism section. The low-stage compression mechanism 11 of the multi-cylinder rotary compressor 2 of the first embodiment is a rolling piston type, whereas the low-stage compression mechanism of the multi-cylinder rotary compressor 2A of the second embodiment. The part 11A is a sliding vane type.

  FIG. 4 is a longitudinal sectional view of a multi-cylinder rotary compressor 2A according to the second embodiment. The low-stage compression mechanism 11A is a mechanism that compresses a low-pressure gas refrigerant into an intermediate-pressure gas refrigerant. As shown in FIG. 4, a cylinder 52 having a cylinder chamber 51 therein and a piston 53 that rotates at a position eccentric from the center in the cylinder chamber 51 are provided. A pair of vane slots 54 is formed in the piston 53. These vane slots 54 are accommodated so that the vanes described later can be moved or moved in contact with each other. The piston 53 is fitted and fixed to the lower end side of the drive shaft 55 of the electric motor unit 10. Both ends of the cylinder 52 are closed by bearings 56 that rotatably support the drive shaft 55. The cylinder chamber 51 is formed so as to be surrounded by a cylinder 52 and a pair of bearings 56. The cylinder chamber 51 is connected to the accumulator 8 by a supply pipe 28. A pair of eccentric portions 18 and 18 are formed on the upper end side of the drive shaft 55, and the high-stage compression mechanism portion 12 is connected to the upper end side of the drive shaft 55.

  A discharge muffler 29 is provided on the outer surface of the lower stage compression mechanism 11A. An intermediate-pressure gas refrigerant compressed in the cylinder chamber 51 is discharged into the discharge muffler 29. A discharge gap 30 is formed between the discharge muffler 29 and the upper bearing 56. The intermediate-pressure gas refrigerant discharged from the cylinder chamber 51 into the discharge muffler 29 is further discharged to the internal space 9 a of the sealed case 9 through the discharge gap 30. Thereby, the internal space 9a of the sealed case 9 is filled with the intermediate-pressure gas refrigerant.

  FIG. 5 is a cross-sectional view taken along the line BB in FIG. 4 and shows a structure inside the cylinder 52. A cylinder chamber 51 is provided in the cylinder 52, and the piston 53 is accommodated in the cylinder chamber 51 so as to be able to rotate. A drive shaft 55 is fixed to the center of the piston 53 using a key 57. Therefore, the drive shaft 55 and the piston 53 rotate integrally. A pair of vane slots 54 are formed in the piston 53, and the vanes 58 are accommodated in these vane slots 54 so as to be movable while being in contact with the cylinder chamber 51. An oil hole 55a for supplying lubricating oil to the vane 58 and the bearing 56 is formed at the center of the lower end of the drive shaft 55 where the piston 53 is fixed.

  When the piston 53 rotates, the vane 58 rotates in the cylinder chamber 51 together with the piston 53 in a state where the tip of the vane 58 is in contact with the inner peripheral surface of the cylinder chamber 51 due to centrifugal force and the pressure of lubricating oil acting in the vane slot 54. To do. When the vane 58 makes its tip contact the inner peripheral surface of the cylinder chamber 51, the cylinder chamber 51 is partitioned into two spaces, and the gas refrigerant is compressed in each space. A discharge valve 59 for discharging the intermediate-pressure gas refrigerant compressed in the cylinder chamber 51 is provided on the outer periphery of the cylinder chamber 51 in the cylinder 52. The intermediate-pressure gas refrigerant discharged from the discharge valve 59 is discharged into the discharge muffler 29 through the discharge passage 60.

  In the present embodiment, the case where a pair of vanes 58 is provided on the piston 53 has been described as an example. However, the number of vanes 58 provided on the piston 53 is not limited, and three or more vanes 58 may be provided. Good.

  In such a configuration, in the multi-cylinder rotary compressor 2A of the second embodiment, the piston 53 rotates in the cylinder chamber 51 of the low-stage compression mechanism 11A, so that the low-pressure gas refrigerant is supplied to the supply pipe 28. And is sucked into the cylinder chamber 51. This low-pressure gas refrigerant is a refrigerant from which the liquid refrigerant has been removed in the accumulator 8. The low-pressure gas refrigerant sucked into the cylinder chamber 51 is compressed by the rotation of the piston 53 in the cylinder chamber 51 and becomes an intermediate-pressure gas refrigerant. This intermediate-pressure gas refrigerant is discharged from the cylinder chamber 51 into the discharge muffler 29. The intermediate-pressure gas refrigerant discharged into the discharge muffler 29 is discharged into the internal space 9a of the sealed case 9 through the discharge gap 30, so that the internal space 9a is filled with the intermediate-pressure gas refrigerant.

  The intermediate-pressure gas refrigerant in the internal space 9 a is sucked into the cylinder chamber 33 of the high-stage compression mechanism 12 via the intermediate-pressure pipe 40, as in the first embodiment. Compressed into high-pressure gas refrigerant.

  Here, in a compressor employing multi-stage compression, the suction volume flow rate and the discharge volume flow rate of the gas refrigerant tend to increase on the low stage side because the displacement volume is large and the compression ratio is small. For this reason, the pulsation due to the suction and discharge of the gas refrigerant is increased, which tends to increase vibration and noise and decrease the compression performance. In particular, if the discharge pulsation is large, the vibration and the compression performance are likely to deteriorate due to interference with the suction pulsation on the higher stage side.

  In contrast, in the multi-cylinder rotary compressor 2A of the present embodiment, a pair of vanes 58 is provided with the low-stage compression mechanism 11A as a sliding vane type. Accordingly, the cylinder chamber 51 can be divided into a plurality of sections easily and at a lower cost than other types of positive displacement compressors, and thus the volumetric flow rate per section can be reduced. For this reason, suction pulsation and discharge pulsation can be reduced, and a multi-cylinder rotary compressor 2A with small pulsation and high compression performance can be obtained.

  Further, in the sliding vane type compression mechanism portion, it is not necessary to provide a blade outside the inner diameter of the cylinder chamber 51 as compared with the rolling piston type compression mechanism portion. The inner diameter can be increased. For this reason, the low stage side compression mechanism part 11A with high volumetric efficiency can be obtained.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIGS.

  The multi-cylinder rotary compressor 2B of the third embodiment is a device that compresses a gas refrigerant in two stages. FIG. 6 is a longitudinal sectional view of a multi-cylinder rotary compressor 2B of the third embodiment. As shown in FIG. 6, the multi-cylinder rotary compressor 2 </ b> B has a cylindrical hermetic case 9 that is arranged in a vertical direction in the vertical direction and is formed in an airtight state. An electric motor unit 61, a low-stage compression mechanism unit 62, and a high-stage compression mechanism unit 63 are accommodated in the sealed case 9. The low-stage compression mechanism 62 is disposed on the lowermost side, the high-stage compression mechanism 63 is disposed adjacent thereto, and the motor 61 is disposed thereon. The sealed case 9 stores lubricating oil that lubricates the sliding portions and the bearing portions of the low-stage compression mechanism 62 and the high-stage compression mechanism 63.

  The electric motor unit 61 includes a stator 64 and a rotor 65. The stator 64 is fixed by being attached to the inner peripheral portion of the sealed case 9 by adhesion or pressure, and the rotor 65 is rotatably inserted inside the stator 64. A drive shaft 66 is fixed to the central portion of the rotor 65. The drive shaft 66 extends downward, and the high-stage compression mechanism 63 and the low-stage compression mechanism 62 are connected. In the middle of the drive shaft 66, two eccentric portions 67 and 67 are formed that are eccentric and project with respect to the axis of the drive shaft 66 and have a phase of 180 ° along the rotation direction of the drive shaft 66. ing.

  The low-stage compression mechanism 62 is a mechanism that compresses a low-pressure gas refrigerant into an intermediate-pressure gas refrigerant. The low-stage compression mechanism 62 includes a cylinder 69 provided with a cylinder chamber 68 and a piston 70 that rotates at a position eccentric from the center in the cylinder chamber 68. A pair of vane slots 71 and 71 are formed in the piston 70. These vane slots 71 are accommodated so that the vanes described later can be moved or moved in contact with each other. The piston 70 is fitted and fixed to one end side of a drive shaft 66 extending downward from the electric motor unit 61. Both ends of the cylinder 69 are closed by a bearing 72 and an intermediate bearing 73 that rotatably support the drive shaft 66.

  The intermediate bearing 73 is disposed between the low-stage compression mechanism 62 and the high-stage compression mechanism 63, and is fixed to the sealed case 9 by spot welding or the like. The cylinder chamber 68 is formed so as to be surrounded by a cylinder 69, a bearing 72, and an intermediate bearing 73. The accumulator 8 is connected to the cylinder chamber 68 by a supply pipe 28.

  The high-stage compression mechanism 63 is a mechanism that further compresses the intermediate-pressure gas refrigerant compressed by the low-stage compression mechanism 62 to obtain a high-pressure gas refrigerant. The high-stage compression mechanism 63 has two compression parts 74 and 75. The two compression parts 74 and 75 each include a cylinder 77, a roller 78, and a blade 79. The cylinder 77 includes a cylinder chamber 76 inside. The roller 78 is accommodated in the cylinder chamber 76 so as to be capable of eccentric rotation while a part of the outer peripheral surface is in contact with the inner peripheral surface of the cylinder chamber 76. The blade 79 is provided so as to be able to appear and retract in the cylinder 77, and the tip of the blade 79 is brought into contact with the outer peripheral surface of the roller 78 to bisect the inside of the cylinder chamber 76 along the rotation direction of the roller 78. On the back side of the blade 79, a blade back chamber 80 isolated from the internal space 9a of the sealed case 9 is provided. The blade back chamber 80 is supplied with the high-pressure lubricating oil separated by the oil separator 3, and the pressure of the lubricating oil causes the blade 79 to be pressed in a direction in which the tip of the blade 79 contacts the outer peripheral surface of the roller 78.

  The drive shaft 66 is disposed so as to penetrate the two cylinder chambers 76 and 76. Eccentric parts 67 and 67 formed on the drive shaft 66 are located in the cylinder chamber 76, and a roller 78 is fitted to these eccentric parts 67. By fitting the roller 78 to the eccentric portions 67 and 67, the roller 78 rotates eccentrically in the cylinder chamber 76 as the drive shaft 66 rotates.

  A partition plate 81 is disposed between the two compression portions 74 and 75, and one end face of each cylinder 77 is closed by the partition plate 81. The other end face of the cylinder 77 of the upper compression portion 74 is closed by a bearing 82 that supports the drive shaft 66 rotatably. On the other hand, the other end surface of the cylinder 77 of the lower compression portion 75 is closed by an intermediate bearing 73 that rotatably supports the drive shaft 66.

  A discharge muffler 29 is provided on the outer periphery of the high-stage compression mechanism 63. An intermediate pressure gas refrigerant compressed in the cylinder chamber 68 is discharged into the discharge muffler 29. A discharge gap 30 is formed between the discharge muffler 29 and the bearing 82. The intermediate-pressure gas refrigerant discharged from the cylinder chamber 68 into the discharge muffler 29 is further discharged to the internal space 9 a of the sealed case 9 through the discharge gap 30. Thereby, the internal space 9a of the sealed case 9 is filled with the intermediate-pressure gas refrigerant.

  An intermediate pressure pipe 83 that guides the intermediate-pressure gas refrigerant in the sealed case 9 to the suction side of the high-stage compression mechanism 63 is provided outside the sealed case 9. The position of the connecting portion 84 where the intermediate pressure pipe 83 and the sealed case 9 are connected is above the motor portion 61.

  An oil return hole 85 for connecting the intermediate pressure pipe 83 and the internal space 9 a of the sealed case 9 is formed in a portion of the intermediate pressure pipe 83 connected to the upper compression portion 74 and inside the sealed case 9. Is formed. The oil return hole 85 is located below the rotor 65 of the electric motor unit 61.

  A discharge pipe 86 is provided on the discharge side of the high-stage compression mechanism 63, and the discharge pipe 86 is connected to the oil separator 3. The oil separator 3 is a device that separates the lubricating oil contained in the high-pressure gas refrigerant compressed by the high stage compression mechanism 63. The high-pressure gas refrigerant from which the lubricating oil has been separated by the oil separator 3 is supplied to a place that requires the gas refrigerant, for example, the outdoor heat exchanger 5 of the air conditioner 1. One end of a lubricating oil supply path 46 is connected to the bottom of the oil separator 3, and the other end of the lubricating oil supply path 46 is connected to the lubricating oil supply port 47 of the high-stage compression mechanism 63.

  FIG. 7 is a cross-sectional view taken along the line CC in FIG. 6 and shows a structure inside the cylinder 69. A cylinder chamber 68 is provided in the cylinder 69. In the cylinder chamber 68, a piston 70 is rotatably accommodated. A drive shaft 66 is fixed to the central portion of the piston 70 using a key 57. Therefore, the drive shaft 66 and the piston 70 rotate integrally. A pair of vane slots 71, 71 are formed in the piston 70, and a vane 87 is accommodated in the vane slot 71 in a state where the vane 87 is in contact with the cylinder chamber 68 and can be moved. An oil hole 66a is formed at the center of the lower end of the drive shaft 66 where the piston 70 is fixed. Lubricating oil is supplied to the vane 87, the bearing 72, and the intermediate bearing 73 from the oil hole 66a.

  When the piston 70 rotates, the vane 87 is brought into contact with the inner peripheral surface of the cylinder chamber 68 in the cylinder chamber 68 together with the piston 70 by centrifugal force and pressure of lubricating oil acting in the vane slot 71. Rotate. The vane 87 makes its tip contact with the inner peripheral surface of the cylinder chamber 68, whereby the cylinder chamber 68 is partitioned into two spaces, and the gas refrigerant is compressed in each partition. A discharge valve 59 is provided on the outer peripheral portion of the cylinder chamber 68 in the cylinder 69. An intermediate pressure gas refrigerant compressed in the cylinder chamber 68 is discharged from the discharge valve 59. The intermediate-pressure gas refrigerant discharged from the discharge valve 59 is discharged into the discharge muffler 29 through the discharge passage 60.

  In this embodiment, the case where the piston 70 is provided with a pair of vanes 87 and 87 has been described as an example. However, the number of vanes 87 provided on the piston 70 is not limited, and three or more vanes 87 are provided. May be.

  In such a configuration, when the multi-cylinder rotary compressor 2B is operated, the electric motor unit 61 is driven and the drive shaft 66 rotates. As the drive shaft 66 rotates, the piston 70 of the low-stage compression mechanism 62 rotates in the cylinder chamber 68 and compresses the gas refrigerant. In addition, the roller 78 of the high-stage compression mechanism 63 rotates eccentrically in the cylinder chamber 76 and compresses the gas refrigerant.

  The flow of the gas refrigerant compressed by the low stage compression mechanism 62 and the high stage compression mechanism 63 will be described below.

  As the piston 70 rotates in the cylinder chamber 68 of the low-stage compression mechanism 62, low-pressure gas refrigerant is sucked into the cylinder chamber 68 from the accumulator 8 via the supply pipe 28. The low-pressure gas refrigerant sucked into the cylinder chamber 68 is compressed in the cylinder chamber 68 to become an intermediate-pressure gas refrigerant. The gas refrigerant having the intermediate pressure is discharged from the cylinder chamber 68 into the discharge muffler 29. The intermediate-pressure gas refrigerant discharged into the discharge muffler 29 is discharged through the discharge gap 30 into the internal space 9a of the sealed case 9, so that the internal space 9a is filled with the intermediate-pressure gas refrigerant.

  The intermediate-pressure gas refrigerant in the internal space 9 a is sucked into the cylinder chamber 76 of the high-stage compression mechanism 63 via the intermediate-pressure pipe 83. The intermediate-pressure gas refrigerant sucked into the cylinder chamber 76 of the high-stage compression mechanism 63 is compressed by the roller 78 eccentrically rotating in the cylinder chamber 76, and becomes high-pressure gas refrigerant. The high-pressure gas refrigerant is discharged out of the sealed case 9 via the discharge pipe 86 and flows into the oil separator 3.

  The high-pressure gas refrigerant that has flowed into the oil separator 3 is separated from the lubricating oil contained in the gas refrigerant. The high-pressure gas refrigerant from which the lubricating oil has been separated is supplied to a place that requires the gas refrigerant, for example, the outdoor heat exchanger 5 of the air conditioner 1. On the other hand, the lubricating oil separated by the oil separator 3 is supplied from the lubricating oil supply port 47 to the blade back chamber 80 and the bearing portion of the high-stage compression mechanism 63 via the lubricating oil supply path 46.

  Here, the position of the connecting portion 84 to which the intermediate pressure pipe 83 and the sealed case 9 are connected is above the electric motor portion 61. For this reason, the intermediate-pressure gas refrigerant discharged from the discharge gap 30 of the discharge muffler 29 to the internal space 9 a of the sealed case 9 passes through the electric motor unit 61 and reaches the connecting unit 84 positioned above the electric motor unit 61. . Then, it flows into the intermediate pressure pipe 83 from the connection portion 84.

  As described above, the motor unit 61, the low-stage compression mechanism unit 62 and the high-stage compression mechanism unit 63 located below the motor unit 61 are accommodated in the sealed case 9, and the low-stage compression mechanism unit The position of the connecting portion 84 where the intermediate pressure pipe 83 and the sealed case 9 are connected to guide the intermediate pressure working fluid discharged from the 62 into the sealed case 9 to the suction side of the high-stage compression mechanism 63 is the electric motor portion 61. It is higher. Therefore, the electric motor unit 61 can be cooled by the intermediate-pressure working fluid, and overheating of the electric motor unit 61 can be prevented.

  Further, when the intermediate-pressure gas refrigerant passes through the electric motor unit 61, lubricating oil contained in the gas refrigerant adheres to the electric motor unit 61. That is, when the intermediate-pressure gas refrigerant flows into the intermediate-pressure pipe 83, the lubricating oil contained in the intermediate-pressure gas refrigerant decreases. Therefore, the inflow of lubricating oil into the cylinder chamber 76 of the high stage compression mechanism 63 to which the intermediate pressure pipe 83 is connected can be suppressed.

  Next, when the lubricating oil supplied from the oil separator 3 to the high-stage compression mechanism 63 via the lubricating oil supply passage 46 returns to the sealed case 9 during the operation of the multi-cylinder rotary compressor 2B. Furthermore, the oil level of the lubricating oil in the sealed case 9 may rise.

  When the oil level of the lubricating oil in the sealed case 9 rises and the oil level reaches the position of the oil return hole 85, the lubricant is sucked into the intermediate pressure pipe 83 through the oil return hole 85. Furthermore, the lubricating oil is sucked into the high-stage compression mechanism 63 together with the intermediate-pressure gas refrigerant flowing in the intermediate-pressure pipe 83. For this reason, the liquid level of the lubricating oil in the sealed case 9 does not rise from the position of the oil return hole 85. And since the position of this oil return hole 85 is below the rotor 65 of the electric motor part 61, it does not occur that the rotor 65 of the electric motor part 61 is immersed in the lubricating oil in the sealed case 9. Therefore, it is possible to prevent a situation in which the rotation resistance is increased due to the rotor 65 being immersed in the lubricating oil and the performance of the multi-cylinder rotary compressor 2B is deteriorated.

  Further, since the position of the oil return hole 85 is located above the cylinder chamber 68 of the low-stage compression mechanism 62, when there is sufficient lubricating oil in the sealed case 9, the periphery of the cylinder chamber 68 is It is always filled with lubricating oil. Therefore, the lubricating oil can be easily supplied to the contact portion in the cylinder chamber 68 and the seal portion of the cylinder chamber 68 by the differential pressure inside and outside the cylinder chamber 68. Thereby, the performance and reliability of the multi-cylinder rotary compressor 2B can be improved.

  An intermediate bearing 73 that supports the drive shaft 66 is provided between the low-stage compression mechanism 62 and the high-stage compression mechanism 63 that are disposed adjacent to each other. The intermediate bearing 73 is spot welded to the sealed case 9 and fixed. For this reason, even if the low stage side compression mechanism part 62 and the high stage side compression mechanism part 63 are arrange | positioned adjacently, the bending of the drive shaft 66 can be prevented by the intermediate bearing 73, and a multi-cylinder rotary compression The performance and reliability of the machine 2B can be improved.

  As described above, the motor unit 61, the low-stage compression mechanism unit 62 and the high-stage compression mechanism unit 63 located below the motor unit 61 are accommodated in the sealed case 9, and the low-stage compression mechanism unit The position of the connecting portion 84 where the intermediate pressure pipe 83 and the sealed case 9 are connected to guide the intermediate pressure working fluid discharged from the 62 into the sealed case 9 to the suction side of the high-stage compression mechanism 63 is the electric motor portion 61. Since it is higher, the electric motor part 61 can be cooled by the working fluid of intermediate pressure.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

Industrial applicability

  The present invention is used in a multi-cylinder rotary compressor.

Claims (6)

A sealed case;
An electric motor housed in the sealed case;
Located below the electric motor part, accommodated in the sealed case, driven by the electric motor part, compresses the low-pressure working fluid to an intermediate pressure, and discharges the compressed intermediate pressure working fluid into the sealed case A low-stage compression mechanism,
A high stage that is positioned above the electric motor part, is accommodated in the sealed case, is driven by the electric motor part, and compresses the intermediate-pressure working fluid discharged from the low-stage compression mechanism part into a high-pressure working fluid. A side compression mechanism,
An intermediate pressure pipe that is provided outside the sealed case and guides an intermediate pressure working fluid in the sealed case to the suction side of the high-stage compression mechanism;
A branch pipe communicating the intermediate pressure pipe and the inside of the sealed case;
Have
The position of the communication portion where the intermediate pressure pipe and the sealed case communicate with each other is above the motor portion;
The position of the communication part where the branch pipe communicates with the sealed case is below the rotor of the electric motor part.
A multi-cylinder rotary compressor characterized by that.   2. The multi-cylinder according to claim 1, wherein a position of the communication portion where the branch pipe communicates with the sealed case is above a cylinder chamber provided inside the low-stage compression mechanism portion. Rotary compressor. An oil separator that separates lubricating oil from a high-pressure working fluid discharged from the high-stage compression mechanism;
A lubricating oil supply path for supplying the lubricating oil separated by the oil separator to the high-stage compression mechanism, and
The position of the communicating portion where the lubricating oil supply path and the oil separator communicate with each other is lower than the communicating portion where the lubricating oil supply path and the high-stage compression mechanism portion communicate with each other. The multi-cylinder rotary compressor according to claim 1.   The first suction position where the low-pressure working fluid is sucked into the low-stage compression mechanism and the second suction position where the medium-pressure working fluid is sucked into the high-stage compression mechanism are the driving of the electric motor section. The multi-cylinder rotary compressor according to claim 1, wherein the multi-cylinder rotary compressor is at different positions along the rotation direction of the shaft.   The low-stage compression mechanism is provided with a cylinder having a cylinder chamber therein, a piston that rotates at a position eccentric from the center of the cylinder chamber, and a piston that can be projected and retracted from the piston. The multi-cylinder rotary compressor according to claim 1, further comprising a plurality of vanes that abut on an inner peripheral surface and divide the cylinder chamber into a plurality of spaces. The multi-cylinder rotary compressor according to any one of claims 1 to 5, a condenser connected to the multi-cylinder rotary compressor, an expansion device connected to the condenser, and the expansion device And an evaporator connected between the multi-cylinder rotary compressor.

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