JP2007162679A - Fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably feed a lubricating oil to the sliding parts of a plurality of fluid machines contained in a hermetic container. <P>SOLUTION: A compressor 20 and an expander 30 connected to each other through a drive shaft are disposed in the hermetic container 10. A lubricating oil feed route 29 for the compressor for feeding the lubricating oil lubricating the sliding parts of the compressor 20 is formed in the compressor drive shaft 27 of the compressor 20. A lubricating oil feed route 38 for the expander for feeding the lubricating oil lubricating the sliding parts of the expander 30 is formed in the expander drive shaft 37 of the expander 30 independently of the lubricating oil feed route 29 for the compressor. An oil feed pipe part 50 axially extending from the end face of the compressor drive shaft 27 and composing a part of the lubricating oil feed route 29 for the compressor extends through the inside of the lubricating oil feed route 38 for the expander so that the expander drive shaft 27 can be structured in a double tube. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fluid machine used for a refrigeration air conditioner and the like, and more particularly to a lubricating oil supply mechanism of a fluid machine in which a fluid machine such as a compressor or an expander is integrated.

  Conventionally, a compressor is used as a fluid machine for compressing and circulating a refrigerant in a refrigeration cycle. Furthermore, in recent years, there is an attempt to recover the pressure energy of the refrigerant in the process of decompressing the refrigerant whose pressure has been increased by the compressor by using an expander instead of the expansion valve. A rotary type such as a rotary type, a swing type, or a scroll type is used as the compressor, and a rotary type such as a rotary type, a swing type, or a scroll type is used as the expander. Since these rotating mechanisms have bearings and sliding portions, a highly reliable oil supply mechanism that stably lubricates these bearings and sliding portions is required.

  On the other hand, in a fluid machine in which a compressor, an expander, and an electric motor are housed in a single sealed container and provided coaxially, an oil supply path to the compressor and expander is provided in the coaxial drive shaft for compression. The drive shaft of the machine and the drive shaft of the expander are connected through a connecting portion, and a coaxial oil supply path provided in each drive shaft is connected to one, and the fluid machine is connected via the oil supply path. An example in which lubricating oil is supplied to a sliding portion or the like is disclosed (for example, see Non-Patent Document 1).

  An example of such a conventional fluid machine is shown in FIG. FIG. 7 is a sectional view of a conventional fluid machine. As shown in FIG. 7, a compressor 71, an expander 72, and an electric motor 73 are housed in a sealed container 70. The compressor drive shaft 74 and the expander drive shaft 75 are connected via a connecting portion 90. In the connecting portion 90, the compressor drive shaft 74 and the expander drive shaft 75 are configured such that power is transmitted by fitting a hexagonal male portion and a female portion having a clearance in consideration of assembly tolerances. Has been. Further, an oil supply path 76 shared by the compressor 71 and the expander 72 is provided inside the compressor drive shaft 74 and the expander drive shaft 75, and these oil supply paths 76 are also connected via a connecting portion 90. . Since it is difficult to make the compressor drive shaft 74 and the expander drive shaft 75 as a single shaft due to restrictions in the assembly process, the compressor drive shaft 74 and the expander drive shaft 75 are connected after being formed as separate parts. A lubricating oil reservoir 78 is provided at the lower part of the sealed container 70, and the lower end of the oil supply path 76 is immersed in the lubricating oil reservoir 78.

  When the compressor 71 is operated by the electric motor 73, the refrigerant gas is sucked from the compressor suction port 79 and compressed. The compressed refrigerant gas is guided from the passage 80 to the sealed space 81 and discharged from the compressor discharge port 82. The refrigerant discharged from the compressor discharge port 82 passes through a radiator (not shown), is then sucked into the expander 72 from the expander suction port 83, expands, and is discharged from the expander discharge port 84.

When the fluid machine is operated in this way, the suction side of the compressor 71 and the discharge side of the expander 72 become low pressure. Along with the rotation of the electric motor 73, an oil supply pump 85 provided at the lower portion of the compressor drive shaft 74 is driven to pump up the lubricating oil from the lubricating oil reservoir 78 into the oil supply path 76. The pumped lubricating oil communicates with the oil supply path 76 and flows into a bearing of the compressor 71 through a communication hole 86 provided in the compressor drive shaft 74 to lubricate the bearing, and the compressor 71 is utilized by utilizing the differential pressure. It is refueled inside. On the other hand, the lubricating oil that has reached the upper expander 72 flows into the bearing of the expander 72 from the communication hole 87 provided in the expander drive shaft 75 in communication with the oil supply path 76, lubricates the bearing, and differential pressure It is comprised so that oil may be supplied to the inside of the expander 72 using.
"Development of two-phase flow expander / compressor for CO2 air conditioner" Leading research and development of effective energy utilization basic technology March 2003 (Germany) New Energy and Industrial Development Organization

  As described above, in a fluid machine having a plurality of fluid machines such as a compressor and an expander, a drive shaft in which a common oil supply path is formed in each fluid machine is connected via a connecting portion. However, when a fluid machine having such a connecting part of the drive shaft is operated, the lubricating oil pumped up by the oil pump from the clearance of the connecting part leaks into the sealed container, and the oil supply to the upper fluid machine becomes insufficient. was there. On the contrary, the high-pressure refrigerant gas in the sealed container enters the oil supply path of the drive shaft through the clearance of the connecting portion, and the oil supply to the upper fluid machine may become unstable. Thus, when oil supply became unstable, there existed a subject that the sliding location of a fluid machine burned out and failed.

  The phenomenon that the oil supply becomes unstable is not caused only by the connecting portion, but occurs even when there is no seam in the oil supply path using a single drive shaft. That is, the problem of destabilization of oil supply is related not only to the structure of the drive shaft but also to various factors such as the dimensions, types, operating conditions, and pressure in the sealed container of the two fluid machines. Although it is considered that oil is preferentially supplied to the fluid machine having a small pressure loss, it is difficult to qualitatively discuss which fluid machine is insufficient or excessive.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a fluid machine with high reliability by stably supplying lubricating oil to the fluid machine.

In order to solve the problems described above, the present invention provides:
A sealed container;
A first fluid machine and a second fluid machine provided inside the sealed container;
A lubricating oil reservoir that is provided in a lower part of the sealed container and stores lubricating oil for lubricating the sliding portions of the first fluid machine and the second fluid machine;
A first drive shaft, which is a drive shaft of the first fluid machine, and is provided with a first oil supply path for supplying the first fluid machine with the lubricating oil in the lubricating oil reservoir;
An oil supply pipe portion extending in the axial direction from the end face of the first drive shaft and constituting a part of the first oil supply path;
The oil supply pipe part has a double pipe structure by passing through the inside, and the second oil supply path for supplying the lubricating oil in the lubricating oil storage part to the second fluid machine is independent of the first oil supply path. A second drive shaft provided inside;
A connecting portion formed by coaxially connecting the first drive shaft and the second drive shaft;
A fluid machine comprising:

  According to the fluid machine of the present invention, the first oil supply path and the second oil supply path are independent from each other, that is, the lubricating oil cannot pass between the first oil supply path and the second oil supply path. Oil supply to the 1st fluid machine and oil supply to the 2nd fluid machine do not interact directly, and it becomes possible to stabilize oil supply to each fluid machine by this. Furthermore, the fluid machine of the present invention includes a connecting portion between the first drive shaft and the second drive shaft. And the oil supply pipe part which comprises a part of 1st oil supply path | route extends from the end surface of a 1st drive shaft to the inside of a 2nd drive shaft, and the double pipe structure is formed. By providing such an oil supply pipe part, the first oil supply path is not exposed at the end face of the first drive shaft, and the first oil supply path can be isolated from the clearance of the connecting part. As a result, it is possible to prevent the lubricating oil from leaking from the connecting portion or the refrigerant from entering the first oil supply path from the connecting portion, and thus without being affected by the assembly accuracy of the connected drive shaft, etc. It is possible to stably supply the lubricating oil to the fluid machine. Moreover, the assembly of the first drive shaft and the second drive shaft is facilitated by passing the oil supply pipe portion inside the second drive shaft.

  Furthermore, the first fluid machine can be arranged at the upper part of the sealed container and the second fluid machine can be arranged at the lower part of the sealed container. Then, the first oil supply path and the second oil supply path may be extended to the lubricating oil reservoir. That is, the oil supply pipe part may extend to the lubricating oil storage part through the inside of the second drive shaft. According to such a configuration, it is possible to stably supply the lubricating oil to the first fluid machine without being affected by the assembly accuracy of the second fluid machine.

  In the case where the first fluid machine is arranged in the upper part of the sealed container, a lubricating oil pump for sending the lubricating oil in the lubricating oil reservoir to the first oil supply path can be further provided in the lower part of the sealed container. By providing the lubricating oil pump in this manner, the lubricating oil can be supplied to the first fluid machine more stably than the differential pressure supply.

  The second drive shaft may have a cylindrical hole forming a second oil supply path inside, and the oil supply pipe portion may be disposed in the cylindrical hole. According to such a configuration, a highly reliable lubricating oil supply path can be formed with a simpler structure, and the lubricating oil can be stably supplied to each fluid machine.

  Further, the first drive shaft may have a cylindrical hole that forms a first oil supply path inside, and the oil supply pipe portion may be formed of a tube processed independently of the first drive shaft. In this case, the tube can be inserted into the cylindrical hole from the opening on the end face of the first drive shaft, and the tube can be fixed to the first drive shaft. According to such a configuration, a highly reliable lubricating oil supply path can be formed with a simpler structure, and the lubricating oil can be stably supplied to each fluid machine.

  In addition, when the cylindrical hole forming the first oil supply path is provided inside the first drive shaft and the oil supply pipe portion is a tube processed independently of the first drive shaft, the tube is press-fitted, screwed The first drive shaft can be fixed by at least one method selected from welding and shrink fitting. According to such a configuration, a highly reliable lubricating oil supply path can be formed with a simpler structure, and the lubricating oil can be stably supplied to each fluid machine.

  Furthermore, the first fluid machine may be a compressor and the second fluid machine may be an expander. According to such a configuration, it is possible to stably supply the lubricating oil to the fluid machine having the compressor and the expander.

In another aspect, the present invention provides:
A sealed container;
A first fluid machine and a second fluid machine provided inside the sealed container;
To lubricate each sliding part of the first fluid machine and the second fluid machine so that the arrangement direction of the first fluid machine and the second fluid machine and the oil surface are parallel to each other. A lubricating oil reservoir for storing the lubricating oil of
A first drive shaft, which is a drive shaft of the first fluid machine, and is provided with a first oil supply path for supplying the first fluid machine with the lubricating oil in the lubricating oil reservoir;
A first lubricating oil pump disposed adjacent to the end of the first drive shaft and sending the lubricating oil in the lubricating oil reservoir to the first oil supply path;
A drive shaft of the second fluid machine, wherein a second oil supply path for supplying the second fluid machine with the lubricating oil of the lubricating oil reservoir is provided inside independently of the first oil supply path. Two drive shafts;
A second lubricating oil pump disposed adjacent to the end of the second drive shaft and sending the lubricating oil in the lubricating oil reservoir to the second oil supply path;
A connecting portion formed by connecting the first drive shaft and the second drive shaft coaxially on the side opposite to the side where the first and second lubricating oil pumps are disposed;
A fluid machine comprising:

  According to the fluid machine of the present invention, the first oil supply path and the second oil supply path are independent from each other, that is, the lubricating oil cannot pass between the first oil supply path and the second oil supply path. Oil supply to the 1st fluid machine and oil supply to the 2nd fluid machine do not interact directly, and it becomes possible to stabilize oil supply to each fluid machine by this. Furthermore, according to the fluid machine of the present invention described above, the alignment direction of the first fluid machine and the second fluid machine is parallel to the horizontal direction, and is adjacent to each end of the first drive shaft and the second drive shaft. A lubricating oil pump is provided, and the first driving shaft and the second driving shaft are connected to the side opposite to the side where the lubricating oil pump is disposed. According to such a configuration, although the plurality of lubricating oil pumps are provided, the distance between each lubricating oil pump and the lubricating oil can be made closer, so the suction port portion of each lubricating oil pump can be shortened, It is advantageous for space saving.

  As described above, according to the fluid machine of the present invention, it is possible to stably supply the lubricating oil and to realize a highly reliable fluid machine.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The rotary fluid machine of the present invention means a rotary compressor, a rotary expander, a scroll compressor, and a scroll expander.

(First embodiment)
FIG. 1 is a sectional view of a fluid machine according to a first embodiment of the present invention. In the fluid machine 200 according to the present embodiment, the compressor 20 as the first fluid machine is arranged in the upper part of the sealed container 10, the expander 30 as the second fluid machine is arranged in the lower part, and the electric motor 40 is arranged in the central part. It has a configuration.

  The lower part (bottom part) of the airtight container 10 is provided with a lubricating oil storage part 11 for storing lubricating oil for lubricating the sliding parts and bearings of the compressor 20 and the expander 30, and a sealed space above the oil surface. 16 is formed. A suction pipe 12 for sucking refrigerant gas into the compressor 20 and a discharge pipe 13 for discharging refrigerant gas, and a suction pipe 14 for sucking the refrigerant gas into the expander 30 and refrigerant gas are discharged to the outer peripheral portion of the sealed container 10. A discharge pipe 15 is provided.

  The compressor 20 is a scroll compressor, and mainly has a bearing member 21, a compressor drive shaft 27 having an eccentric portion 27 a rotatably supported on the bearing member 21, and an eccentric portion 27 a so as to be rotatable. The orbiting scroll 24 that is eccentrically rotated, the Oldham ring 28 that is slidably fitted in the grooves provided in the bearing member 21 and the orbiting scroll 24 and suppresses the rotation of the orbiting scroll 24, and the orbiting scroll 24. It is comprised with the fixed scroll 22 which is provided facing and forms the several compression chamber 23. As shown in FIG. The compressor 20 is provided with a suction port 25 that is connected to the suction pipe 12 and supplies refrigerant to the outermost compression chamber 23.

  When electric power is supplied to the electric motor 40 to generate rotational power, the compressor drive shaft 27 rotates and the orbiting scroll 24 performs an orbiting motion. Due to the orbiting motion of the orbiting scroll 24, the compression chamber 23 moves from the outer peripheral side toward the center while gradually reducing the volume, thereby compressing the refrigerant. The compressor 20 is provided with a discharge port 26 through which the compressed refrigerant is discharged from the most central compression chamber 23 into the sealed container 10. The refrigerant exiting the discharge port 26 is discharged from the discharge pipe 13 to the outside of the sealed container 10 through the sealed space 16.

  A compressor drive shaft 27 that is a drive shaft of the compressor 20 is rotatably supported on the bearing member 21, and an orbiting scroll 24 is rotatably fitted to an eccentric portion 27 a of the compressor drive shaft 27. ing.

  A back pressure chamber formed by the orbiting scroll 24, the bearing member 21, and the fixed scroll 22 is cut off from the sealed space 16 by a seal ring provided on the sliding surface of the bearing member 21 and the orbiting scroll 24. At the lower end of the compressor drive shaft 27, a part of a compressor lubricant supply path 29, which is a dedicated lubricant supply path for supplying lubricant to the sliding parts and bearings of the compressor 20, is provided. The oil supply pipe portion 50 is provided independently of an expander lubricating oil supply path 38 to be described later. The oil supply pipe portion 50 extends in the axial direction from the end surface of the compressor drive shaft 27, and the lower end thereof extends to the lubricating oil storage portion 11 and is immersed in the lubricating oil. The compressor drive shaft 27 has a cylindrical hole that forms the remaining portion of the compressor lubricant supply path 29. In addition, the orbiting scroll 24 is provided with an oil hole 24 a that communicates with the compressor lubricating oil supply path 29 and communicates with the back pressure chamber and an oil hole 24 b that communicates with the bearing member 21. Although not shown, oil holes for supplying lubricating oil from the compressor lubricating oil supply passage 29 to other sliding portions and bearing portions are also provided as appropriate.

  The expander 30 is of a type called a rotary expander, and the expansion chamber 34 is formed by an upper bearing member 31, a lower bearing member 32, a cylinder 33, a piston 35, and a vane (not shown). An expander drive shaft 37 that is a drive shaft of the expander 30 is rotatably supported on the upper bearing member 31 and the lower bearing member 32, and the piston 35 is rotatable on an eccentric portion 37 a of the expander drive shaft 37. Fit and hold. When high-pressure refrigerant gas is injected into the expansion chamber 34 from the suction port 31a through the suction pipe 14, the piston 35 is rotated by the pressure of the refrigerant gas, and rotational force is applied to the expander drive shaft 37 via the eccentric portion 37a. It has a structure to convey. The refrigerant gas that has caused the expander drive shaft 37 to rotate is discharged from the discharge port 31b. The expander drive shaft 37 has a substantially cylindrical shape except for the eccentric portion 37a. The expander drive shaft 37 and the compressor drive shaft 27 are connected coaxially to form a connecting portion 100.

  In the first embodiment of the present invention, as shown in FIG. 1, an oil supply pipe portion 50 is inserted into an expander drive shaft 37 having a substantially cylindrical shape. The expander drive shaft 37 forms a double pipe. The gap formed between the inner peripheral surface of the expander drive shaft 37 and the outer peripheral surface of the oil supply pipe portion 50 is set to be larger than the clearance provided in the connecting portion 100, and the expander drive shaft 37 and the oil supply tube due to misalignment of the shaft center or the like. In addition to having a function of preventing interference with the portion 50, the assembly of the compressor drive shaft 27 and the expander drive shaft 37 can be improved by adopting such a double tube configuration. In this embodiment, the gap constitutes the expander lubricating oil supply path 38. An oil hole 24 c that communicates with the expander lubricating oil supply path 38 and connects from the piston 35 to the cylinder 33 is provided from the expander drive shaft 37 to the eccentric portion 37 a. Further, an oil hole 24d that communicates with the expansion oil supply passage 38 for the expander and is connected to the upper bearing member 31 is also provided, so that the upper bearing member 31 is lubricated. The lower end of the expander lubricating oil supply path 38 is also extended to the lubricating oil reservoir 11 and immersed in the lubricating oil.

  The electric motor 40 includes a rotor 41 fixed to the compressor drive shaft 27 by shrink fitting and a stator 42 fixed to the sealed container 10.

  Next, the operation of the fluid machine 200 in the first embodiment will be briefly described. When the orbiting scroll 24 of the compressor 20 is rotated by the electric motor 40, the refrigerant gas taken in via the suction pipe 12 and the suction port 25 is compressed to a high pressure in the compression chamber 23 and passes through the discharge port 26 and the discharge pipe 13. Discharged. Although the high-pressure refrigerant gas discharged from the discharge pipe 13 is sent to an external radiator connected to the discharge pipe 13 (not shown) to dissipate heat, the suction pipe 14 and the suction port 31a on the expander 30 side are passed through. The air is sucked into the expansion chamber 34 via. The sucked refrigerant gas expands to rotate the piston 35, and transmits the rotational force to the expander drive shaft 37 via the eccentric portion 37a. The refrigerant gas that has caused the expander drive shaft 37 to rotate is discharged through the discharge port 31 b and the discharge pipe 15. By such an operation, energy due to a pressure difference generated in the process of depressurizing the refrigerant compressed by the compressor 20 can be recovered, and the efficiency of the fluid machine 200 can be increased.

  Next, lubrication of the fluid machine 200 in the first embodiment will be described. During the operation of the fluid machine 200, the sealed space 16 of the sealed container 10 is filled with the high-pressure refrigerant gas discharged from the discharge port 26 of the compressor 20, and the lubricating oil stored in the lubricating oil storage unit 11. The pressure is almost equal to that of the high-pressure refrigerant gas. On the other hand, the suction side of the compressor 20 and the inside of the expander 30 are at a lower pressure than the sealed space 16. Due to the differential pressure and the centrifugal effect caused by the oil holes 24a and 24b, the lubricating oil in the lubricating oil reservoir 11 passes through the compressor lubricating oil supply path 29 as shown by the arrow A in FIG. Are supplied to the sliding part and the bearing part. On the other hand, as shown by an arrow B in FIG. 1, the lubricating oil is supplied to the sliding portion and the bearing portion of the expander 30 through the expander lubricant supply path 38.

  2A and 2B are diagrams showing details of the connecting portion 100 in FIG. 1, FIG. 2A is a cross-sectional view, and FIG. 2B is a cross-sectional view taken along line AA in FIG. In FIG. 1, for convenience, the compressor drive shaft 27 of the connecting portion 100 is shown with a bowl-shaped stepped portion. However, since the stepped portion is not particularly required, the stepped portion is not shown in FIG. 2. It is shown as a configuration not provided.

  The expander drive shaft 37 and the compressor drive shaft 27 are connected to each other in the connecting portion 100 by fitting a hexagonal male portion and a female portion with a clearance in consideration of assembly tolerances. As shown in FIG. 2B, a hexagonal male portion 65 provided on the expander drive shaft 37 is fitted with a hexagonal female portion 64 provided on the compressor drive shaft 27 with a clearance d1. Yes. The clearance d <b> 1 is provided so as to allow deviation of the axial center between the compressor drive shaft 27 and the expander drive shaft 37, and a clearance formed between the inner peripheral surface of the expander drive shaft 37 and the outer peripheral surface of the oil supply pipe portion 50. d2 satisfies the relationship d2> d1. Thus, the radial clearance d2 between the inner peripheral surface of the expander drive shaft 37 and the outer peripheral surface of the oil supply pipe portion 50 in the connecting portion 100 is larger than the radial clearance d1 between the male portion 65 and the female portion 64. By enlarging, interference with the expander drive shaft 37 and the oil supply pipe part 50 can be prevented, and as a result, the compressor drive shaft 27 and the expander drive shaft 37 can be smoothly rotated.

  As shown in FIG. 1, the compressor lubricating oil supply path 29 is integrally formed in the compressor drive shaft 27 and extends to the lubricating oil reservoir 11, and has no seam at the connecting portion 100. And it is isolated from the clearance of the connecting part 100. Conventionally, when a fluid machine having a connecting portion of a drive shaft is operated, high-pressure refrigerant gas in the sealed container may enter the oil supply path of the drive shaft from the clearance of the connecting portion. In this case, since the pumping of the lubricating oil through the compressor lubricating oil supply path 29 becomes unstable by the refrigerant gas, there is a problem that the reliability of the sliding portion is impaired.

  On the other hand, in the first embodiment of the present invention, even if a gap occurs in the connecting portion 100, the compressor lubricating oil supply path 29 is isolated from the gap. The oil supply path 29 does not enter, and the lubricant oil can be stably supplied to the compressor 20. In addition, since the expander 30 is immersed in the lubricating oil storage part 11, even if refrigerant gas penetrate | invades from the connection part 100, lubricating oil is stably supplied to a sliding part.

  2, when the compressor drive shaft 27 and the expander drive shaft 37 are assembled, they may be fitted via an elastic body so as to absorb their assembly errors. Further, it is not necessary to strictly ensure the sealing action between the compressor drive shaft 27 and the expander drive shaft 37, but if an O-ring seal or the like is used as an elastic body, it further passes to the expander lubricating oil supply path 38. It is preferable that the refrigerant gas can be prevented from entering.

  In the present embodiment, the rotor 41 of the electric motor 40 arranged between the compressor 20 and the expander 30 is fixed to the compressor drive shaft 27, and the connecting portion 100 is closer to the expander 30 than the electric motor 40. Is located. In general, the expander 30 is cooled to low temperature due to expansion of the refrigerant, so that heat is transferred from the compressor 20 and the electric motor 40 to the expander 30. It is desirable from the viewpoint of energy efficiency to suppress such heat transfer. According to the present embodiment, since the rotor 41 of the electric motor 40 is fixed to the compressor drive shaft 27, the connecting portion 100 serves as a barrier, and the heat transfer from the electric motor 40 to the expander 30 can be suppressed. There is.

  FIG. 3 is a cross-sectional view showing details of another embodiment of the connecting portion 100. In the example of FIGS. 3A and 3B, the oil supply pipe portion 50 is formed of a pipe that is processed and prepared independently of the compressor drive shaft 27. A pipe as the oil supply pipe section 50 is inserted into the cylindrical hole from the opening on the end face of the compressor drive shaft 27 and is fixed to the compressor drive shaft 27.

  In the example of FIG. 3A, in the connecting portion 100, a cylindrical oil supply pipe portion 50 is fitted and fixed to a compressor lubricating oil supply passage 29 formed on the compressor drive shaft 27 by press fitting. The lubricating oil supply path 29 is extended to the lubricating oil reservoir 11. Further, in the example of FIG. 3B, in the connecting portion 100, a cylindrical oil supply pipe portion 51 is fastened with a screw 51 a to a compressor lubricating oil supply path 29 formed on the compressor driving shaft 27. The lubricating oil supply path 29 is extended to the lubricating oil reservoir 11. Further, the oil supply pipe portion 50 may be fixed to the compressor drive shaft 27 by using a method such as welding or shrink fitting. According to these methods, it is possible to easily form a structure in which the compressor lubricant supply passage 29 is not exposed to the clearance of the connecting portion 100, and the assembly is also easy. Since no driving force is applied to the connecting portion between the compressor drive shaft 27 and the oil supply pipe portions 50 and 51, there is a possibility that a gap may occur due to a change with time even when the compressor lubricant supply passage 29 is connected in this way. There is almost no supply of the lubricating oil to the compressor 20 stably.

  Of course, the oil supply pipe section 50 and the compressor drive shaft 27 may be made of a single component. That is, by grinding or cutting a part of one shaft member having a cylindrical hole inside so as to reduce the outer diameter, a compressor drive shaft including a small-diameter portion as the oil supply pipe portion 50 is obtained. It may be.

  In the above description, the compressor lubricating oil supply path 29 including the oil supply pipe portions 50 and 51 is provided coaxially with the rotational axis of the compressor drive shaft 27. By providing a slight inclination with respect to the rotational axis, it is possible to improve the pumping capacity of the lubricating oil by utilizing the centrifugal pump action.

(Second Embodiment)
FIG. 4 is a partial cross-sectional view of a fluid machine 201 according to the second embodiment of the present invention. In FIG. 4, the same components as those in FIG. The second embodiment differs from the first embodiment in that a lubricating oil pump 60 for pumping up lubricating oil is provided in the lubricating oil reservoir 11 at the lower part of the hermetic container 10, and the lubricating oil pump 60 is used for a compressor. The lubricating oil supply path 29 is connected. The lubricating oil pump 60 is fixed to the lower bearing member 32 of the expander 30 with bolts 61. Although not shown, the suction port of the lubricating oil pump 60 opens to the lubricating oil reservoir 11, and the discharge port of the lubricating oil pump 60 connects to the lubricating oil supply path 29 for the compressor formed in the extended oil supply pipe portion 50. It is connected. By operating the lubricating oil pump 60, the lubricating oil in the lubricating oil reservoir 11 is supplied to the sliding portion or the bearing portion of the compressor 20 via the compressor lubricating oil supply path 29. Yes. In the second embodiment of the present invention, the configuration of the oil supply pipe portion 50 in the connecting portion 100 between the compressor drive shaft 27 and the expander drive shaft 37 is the same as the configuration described in the first embodiment. It is.

  As described above, in the second embodiment of the present invention, the lubricating oil is not supplied by utilizing the differential pressure between the inside of the compressor 20 and the sealed space 16 or the centrifugal force of the oil hole 24b. Lubricating oil is pressurized by an oil pump 60 and supplied to a sliding portion or a bearing portion of the compressor 20. Therefore, the sealing performance between the sealed space 16 and the compressor lubricating oil supply passage 29 is ensured, and the supply of the lubricating oil to the compressor 20 is affected by the differential pressure that varies depending on the operating conditions of the refrigeration cycle. Can be carried out stably.

  As the lubricating oil pump 60, a gear pump such as a trochoid pump can be used.

(Third embodiment)
FIG. 5 is a cross-sectional view of a fluid machine 202 according to the third embodiment of the present invention. 5, the same components as those in FIGS. 1 and 4 are denoted by the same reference numerals, and the description thereof is omitted. The third embodiment is different from the second embodiment in that the compressor 20 as the first fluid machine, the expander 30 as the second fluid machine, and the electric motor 40 are horizontally arranged in the sealed container 10. Is being stored. A lubricating oil reservoir 11 is provided in the lower part of the hermetic container 10, and a lubricating oil pump 62 that pumps up the lubricating oil in the lubricating oil reservoir 11 is provided in the expander 30. A lubricating oil supply path 29 and an expander lubricating oil supply path 38 are connected. By operating the lubricating oil pump 62, the lubricating oil in the lubricating oil reservoir 11 is slid on the compressor 20 and the expander 30 via the compressor lubricating oil supply path 29 and the expander lubricating oil supply path 38. It is configured to supply to moving parts and bearings.

  More specifically, the lubricating oil reservoir 11 is provided so that the direction in which the compressor 20 and the expander 30 are aligned, that is, the axial direction of the drive shafts 27 and 37 is parallel to the oil surface, and the lubricating oil reservoir 11, a part of the compressor 12, a part of the stator 42 of the electric motor 40, and a part of the expander 30 (particularly the rear end of the vane) are directly immersed in the lubricating oil stored in 11. The lubricating oil pump 62 provided adjacent to the end of the expander drive shaft 37 extends in a direction (preferably outward in the radial direction) in which the suction port portion 62a intersects the axial direction, and the lubricating oil storage portion 11. The lubricating oil stored in the tank can be sucked. Note that “the axial direction is parallel to the oil surface” does not mean that the axial directions of the drive shafts 27 and 37 are required to be completely parallel (horizontal) to the oil surface, for example, with an inclination of less than about 10 degrees. If there is, it can be regarded as almost parallel.

  Also in the third embodiment of the present invention, the configuration of the oil supply pipe portion 50 in the connecting portion 100 between the compressor drive shaft 27 and the expander drive shaft 37 is the same as the configuration described in the first embodiment. It is.

  Therefore, even when the fluid machine is horizontally arranged as in the third embodiment, the sealing performance between the sealed space 16 and the compressor lubricating oil supply path 29 is ensured, and further the lubrication to the compressor 20 is performed. Oil can be supplied stably without being affected by the differential pressure that varies depending on the operating conditions of the refrigeration cycle.

(Fourth embodiment)
FIG. 6 is a sectional view of a fluid machine 203 according to the fourth embodiment of the present invention. In FIG. 6, the same components as those in FIG. The fourth embodiment differs from the third embodiment in that the compressor 66 is a scroll type compressor in the third embodiment, whereas the rotary type is used in the fourth embodiment. The compressor 66 is used. Since the internal structure of the rotary compressor 66 is almost the same as that of the rotary expander 30, detailed description thereof is omitted. Both the expander 30 and the compressor 66 are provided with a lubricating oil pump 62 and a lubricating oil pump 63 that pump up the lubricating oil in the lubricating oil reservoir 11, and the lubricating oil pump 62 has a lubricating oil supply path 38 for the expander. The lubricating oil pump 63 is connected to a compressor lubricating oil supply path 67 independently. By operating the lubricating oil pump 62 and the lubricating oil pump 63, the lubricating oil in the lubricating oil reservoir 11 passes through the expander lubricating oil supply path 38 and the compressor lubricating oil supply path 67, and the expander 30. The compressor 66 is configured to be supplied to a sliding portion or a bearing portion of the compressor 66.

  According to such a configuration, as described in the first to third embodiments, since it is not necessary to provide two lubricating oil supply paths in the same axis, machining becomes easy. The tolerance for assembling accuracy can be given, and the lubricating oil can be stably supplied to the sliding portions and bearing portions of the compressor 66 and the expander 30. In the fourth embodiment, the case where the compressor 66 is a rotary type has been described. However, it is natural that the compressor 66 is not limited to the rotary type, and a plurality of fluids can be provided by independently providing a lubricating oil supply path. Lubricating oil can be stably supplied to the machine.

  Further, in the fourth embodiment shown in FIG. 6, as in the third embodiment, the configuration in which the axial direction of the drive shafts 27 and 77 is parallel to the horizontal direction is adopted, and the expander drive shaft is used. 27, an expander lubricating oil pump 62 is arranged adjacent to the end of the compressor drive shaft 77, and a compressor lubricating oil pump 63 is arranged adjacent to the end of the compressor drive shaft 77. On the side opposite to the side where the lubricating oil pumps 62 and 63 are disposed, the expander drive shaft 27 and the compressor drive shaft 77 are connected coaxially, thereby forming a connecting portion 101. The expander lubricant supply path 38 is formed only inside the expander drive shaft 27, the compressor lubricant supply path 67 is formed only inside the compressor drive shaft 77, and the connecting portion 101 is the lubricant. Does not include supply channels. Further, the suction port portions 62 a and 63 a of the lubricating oil pumps 62 and 63 extend outward in the radial direction, and their tips are immersed in the lubricating oil stored in the lubricating oil storage portion 11. According to such a configuration, since the distance between the lubricating oil pumps 62 and 63 and the lubricating oil can be made close to each other, the suction port portions 62a and 63a of the lubricating oil pumps 62 and 63 can be shortened to save space. It is advantageous. Further, since the connecting portion 101 does not include the lubricating oil supply path, there is essentially no problem that the lubricating oil leaks from the connecting portion or the refrigerant enters.

  In the above embodiment, an example in which two fluid machines of a compressor and an expander are provided in a sealed container has been shown. However, in a fluid machine other than the compressor and the expander, or in three or more fluid machines, The present invention can also be applied to this.

  As described above, according to the fluid machine of the present invention, it is possible to stably supply the lubricating oil, and to realize a highly reliable fluid machine.

  The fluid machine of the present invention is useful for a fluid machine having a plurality of fluid machines in a sealed container.

Sectional drawing of the fluid machine in the 1st Embodiment of this invention Sectional drawing which shows the detail of the connection part of the fluid machine Sectional drawing which shows the other Example of the connection part of the fluid machine Partial sectional drawing of the fluid machine in the 2nd Embodiment of this invention Sectional drawing of the fluid machine in the 3rd Embodiment of this invention Sectional drawing of the fluid machine in the 4th Embodiment of this invention Cross section of a conventional fluid machine

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sealed container 11 Lubricating oil storage part 12, 14 Suction pipe 13, 15 Discharge pipe 16 Sealed space 20, 66 Compressor 21 Bearing member 22 Fixed scroll 23 Compression chamber 24 Orbiting scroll 24a, 24b, 24c, 24d Oil hole 25, 31a Suction port 26, 31 b Discharge port 27 Compressor drive shaft 27 a, 37 a Eccentric part 28 Oldham ring 29, 67 Compressor lubricating oil supply path 30 Expander 31 Upper bearing member 32 Lower bearing member 33 Cylinder 34 Expansion chamber 35 Piston 37 Expansion Machine drive shaft 38 Lubricating oil supply path for expander 40 Electric motor 41 Rotor 42 Stator 50, 51 Oil supply pipe part 51a Screw 60, 62, 63 Lubricating oil pump 61 Bolt 64 Female part 65 Male part 100, 101 Connecting part 200, 201, 202, 203 Fluid machinery

Claims (10)

A sealed container;
A first fluid machine and a second fluid machine provided inside the sealed container;
A lubricating oil reservoir that is provided in a lower part of the sealed container and stores lubricating oil for lubricating the sliding portions of the first fluid machine and the second fluid machine;
A first drive shaft of the first fluid machine, wherein a first oil supply path for supplying the first fluid machine with lubricating oil in the lubricating oil reservoir is provided therein;
An oil supply pipe portion extending in an axial direction from an end surface of the first drive shaft and constituting a part of the first oil supply path;
The oil supply pipe part has a double pipe structure by passing through the inside, and the second oil supply path for supplying the second fluid machine with the lubricating oil in the lubricating oil storage part is the first oil supply path. A second drive shaft provided inside independently from,
A connecting portion formed by connecting the first drive shaft and the second drive shaft coaxially;
A fluid machine equipped with.   The first fluid machine is provided in an upper part of the inside of the sealed container, and the second fluid machine is provided in a lower part, and the first oil supply path and the second oil supply path extend to the lubricating oil reservoir. Item 2. The fluid machine according to Item 1.   The fluid machine according to claim 2, further comprising a lubricating oil pump provided at a lower portion of the sealed container and sending the lubricating oil in the lubricating oil reservoir to the first oil supply path.   The said 2nd drive shaft has a cylindrical hole which forms the said 2nd oil supply path inside, The said oil supply pipe | tube part is arrange | positioned in the said cylindrical hole. The fluid machine described in 1.   The first drive shaft has a cylindrical hole that forms the first oil supply path inside, and the oil supply pipe portion is a tube processed independently of the first drive shaft, and the first drive shaft The fluid machine according to any one of claims 1 to 4, wherein the pipe is inserted into the cylindrical hole from an opening of an end face of the pipe and fixed to the first drive shaft.   The first drive shaft has a cylindrical hole that forms the first oil supply path, and the oil supply pipe portion is a tube processed independently of the first drive shaft, and the tube is press-fitted, screwed, The fluid machine according to any one of claims 1 to 4, wherein the fluid machine is fixed to the first drive shaft by at least one method selected from welding and shrink fitting. The first drive shaft and the second drive shaft are connected to each other in the connecting portion by fitting a male portion and a female portion,
A radial clearance d2 formed by the inner peripheral surface of the second drive shaft and the outer peripheral surface of the oil supply pipe portion in the connecting portion is larger than the radial clearance d1 between the male portion and the female portion. The fluid machine according to any one of claims 1 to 6.   The fluid machine according to any one of claims 1 to 7, wherein the first fluid machine is a compressor and the second fluid machine is an expander. An electric motor disposed between the first fluid machine and the second fluid machine and having a rotor fixed to the first drive shaft;
The fluid machine according to claim 8, wherein the connecting portion is located closer to the second fluid machine than the electric motor. A sealed container;
A first fluid machine and a second fluid machine provided inside the sealed container;
Each slide of the first fluid machine and the second fluid machine is provided at a lower portion in the sealed container, and the arrangement direction of the first fluid machine and the second fluid machine is parallel to the oil level. A lubricating oil reservoir for storing lubricating oil for lubricating the part;
A first drive shaft of the first fluid machine, wherein a first oil supply path for supplying the first fluid machine with lubricating oil in the lubricating oil reservoir is provided therein;
A first lubricating oil pump disposed adjacent to an end of the first drive shaft and sending the lubricating oil in the lubricating oil reservoir to the first oil supply path;
A drive shaft of the second fluid machine, wherein a second oil supply path for supplying the second fluid machine with the lubricating oil in the lubricating oil reservoir is provided independently of the first oil supply path. A second drive shaft provided;
A second lubricating oil pump disposed adjacent to an end of the second drive shaft and sending the lubricating oil in the lubricating oil reservoir to the second oil supply path;
A connecting portion formed by coaxially connecting the first drive shaft and the second drive shaft on the side opposite to the side where the first and second lubricating oil pumps are disposed;
A fluid machine equipped with.

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