JP2008038643A - Expander integrated compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent thermal short-circuit between a compression mechanism and an expansion mechanism in an expander integrated compressor. <P>SOLUTION: This expander integrated compressor 70 is composed by arranging a compression mechanism 2, a motor 3, and an expansion mechanism in this order from a top in a hermetic vessel 1, connecting the same by a shaft, and providing an oil reservoir part 6 at a bottom part of the hermetic vessel 1. The oil reservoir part is partisioned in an up-and-down direction by an upper bearing member 9, and a bypass oil channel 8 leads oil in an upper side of the upper bearing member 9 to an oil pump 7. Moreover, the upper bearing member 9 is provided with an overflow pipe 10 penetrating therethrough of which upper end part projects out of an upper surface of the upper bearing member 9 by a fixed distance. The bypass oil channel 8 has heat insulating properties. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an expander-integrated compressor for a refrigeration cycle apparatus used in a refrigeration air conditioner or the like. In particular, the present invention relates to a technology for improving the efficiency of an expander-integrated compressor in which a compressor and an expander are provided in the same container.

  As an expander-integrated compressor that is applied to the refrigeration cycle, an expansion mechanism that converts expansion energy into mechanical energy when the refrigerant expands under reduced pressure and a compression mechanism that compresses the refrigerant are integrated, and a shared shaft is used. There exists a thing which aims at the efficiency improvement of a refrigerating cycle by supplying the converted mechanical energy to a compression mechanism (patent document 1).

  Since the compression mechanism adiabatically compresses the refrigerant, the temperature of the members constituting the compression mechanism increases as the temperature of the refrigerant increases. On the other hand, in the expansion mechanism, the refrigerant cooled by the radiator flows in and adiabatic expansion of the refrigerant is performed, so that the temperature of the members constituting the expansion mechanism decreases as the temperature of the refrigerant decreases. Therefore, as described in Patent Document 1, when the compression mechanism and the expansion mechanism are simply integrated adjacent to each other, the heat on the compression mechanism side moves to the expansion mechanism side, so that the expansion mechanism is heated. And the compression mechanism is cooled. Therefore, the enthalpy of the refrigerant discharged from the compression mechanism is reduced, and the heating capacity is reduced. Moreover, the enthalpy of the refrigerant | coolant discharged from an expansion mechanism will increase, and freezing capacity will fall. Therefore, the equipment efficiency of the refrigerating cycle using such an expander-integrated compressor is lowered.

  In view of this, there is one that solves the above problem by providing a heat insulating member between the members of the compression mechanism and the expansion mechanism to inhibit the heat transfer from the compression mechanism to the expansion mechanism (Patent Document 2).

In addition, as shown in FIG. 4, a compression mechanism 102, an electric motor 103, and an expansion mechanism 104 are arranged in this order from the bottom inside the sealed container 101, and heat insulation that inhibits heat transfer from the surrounding fluid on the surface of the expansion mechanism 104. Some have a member 105 (Patent Document 3).
JP-A-62-77562 JP 2001-165040 A Japanese Patent No. 3674625

  FIG. 5 is a longitudinal sectional view of a conventional expander-integrated compressor, and FIG. 6 is a transverse sectional view of a conventional expander-integrated compressor.

  In the conventional expander-integrated compressor, as in the expander-integrated compressor 60 shown in FIGS. 5 and 6, the compression mechanism 2, the electric motor 3, and the expansion mechanism 4 are sequentially arranged inside the sealed container 1. Are arranged from above, connected by a shaft 5, and provided with an oil reservoir 6 at the bottom of the sealed container 1. Here, the compression mechanism 2 installed on the upper side is a scroll type, and the expansion mechanism 4 installed on the lower side is immersed in the oil storage unit 6 at the bottom of the hermetic container 1 to maintain the sealing performance of the refrigerant leakage path. It is said.

  In such a configuration, when the inside of the sealed container 1 is filled with the high-temperature and high-pressure refrigerant discharged from the compression mechanism 2, the periphery of the rotary type expansion mechanism 4 is discharged from the compression mechanism 2. Since it is filled with the high temperature oil in the oil reservoir 6 heated by the high-temperature and high-pressure refrigerant, the heat generated by the electric motor 3, and the frictional heat at each sliding portion, the space between the expansion mechanism 4 and the oil in the oil reservoir 6 Then, heat transfer occurs, the expansion mechanism 4 is heated, and the oil in the oil reservoir 6 is cooled. This oil is used to lubricate the scroll-type compression mechanism 2 installed above and to apply back pressure to prevent the orbiting scroll 14 from overturning, and cools the compression mechanism 2 in the process. As a result, in the refrigeration cycle apparatus using the expander-integrated compressor 60 having the above configuration, the refrigeration capacity and the heating capacity are reduced.

  In order to solve the above problems, it has been considered to use a heat insulating member as described in Patent Document 2 and Patent Document 3, but if a rotary fluid machine is not filled with oil, the refrigerant leaks. As a result, the performance deteriorates and lubrication of the sliding portion becomes insufficient, and if the surface is covered with a heat insulating member, the oil is not supplied sufficiently and the performance is deteriorated due to refrigerant leakage and the reliability of the sliding portion is reduced. It was causing a decline.

  Similarly, when it is necessary to immerse the expansion mechanism 4 in the oil reservoir 6, the above-described problem occurs not only in the rotary expansion mechanism described above.

  Therefore, the present invention suppresses the movement of heat from high-temperature oil to the expansion mechanism even when the expansion mechanism is immersed in an oil reservoir provided inside a container filled with a high-temperature refrigerant, so that the refrigeration cycle apparatus An object is to provide an expander-integrated compressor capable of improving performance.

  The present invention includes a sealed container, a compression mechanism provided in an upper part in the sealed container, an expansion mechanism provided in a lower part in the sealed container, a shaft connecting the compression mechanism and the expansion mechanism, An oil reservoir provided at the bottom of the hermetically sealed container for immersing at least a part of the expansion mechanism; and a suction portion for sucking oil from the oil reservoir; and a lower end of the shaft and below the expansion mechanism. And an oil pump that feeds oil in the oil reservoir to the compression mechanism via an oil passage provided inside the shaft, and sucks oil in the upper layer in the oil reservoir into the oil pump. An expander-integrated compressor having a bypass oil flow path leading to a section is provided.

  According to the expander-integrated compressor of the present invention, the oil pump selectively selects high-temperature oil located in the upper layer of the temperature stratification formed by the temperature difference of the oil accumulated in the oil reservoir. Therefore, high-temperature oil is supplied to the compression mechanism. Therefore, it is possible to suppress the oil supplied to the compression mechanism from cooling the compression mechanism and the refrigerant passing through the compression mechanism, and the temperature is selectively high without disturbing the temperature stratification formed in the oil reservoir. Oil can be delivered to the compression mechanism.

  Also, with the above configuration, the temperature stratification of the oil reservoir is maintained, and the temperature of the oil around the expansion mechanism is maintained near the temperature of the expansion mechanism, so that the heat transfer from the oil to the expansion mechanism is suppressed. Thus, the expansion mechanism by the oil in the oil reservoir and the heating of the refrigerant passing through the expansion mechanism are also suppressed.

  Therefore, in the refrigeration cycle using the expander-integrated compressor of the present invention, the increase of the refrigerant enthalpy after expansion is prevented and sufficient refrigeration capacity is exhibited, and in the heat pump cycle, the refrigerant enthalpy after compression is reduced. Is prevented and sufficient heating capacity is exhibited, so that the efficiency of the device can be improved.

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

(First embodiment)
FIG. 1 is a longitudinal sectional view of an expander-integrated compressor according to the present invention.

  As shown in FIG. 1, the expander-integrated compressor 70 includes a compression mechanism 2, an electric motor 3, and an expansion mechanism 4 arranged in order from the top inside the sealed container 1, and connected by a shaft 5. By providing the oil reservoir 6 at the bottom of the hermetic container 1, the expansion energy of the refrigerant is recovered by the expansion mechanism 4 and superimposed on the power of the electric motor 3 that drives the compression mechanism 2.

  The bottom portion of the hermetic container 1 is an oil storage portion 6 that stores oil. Therefore, the periphery of the expansion mechanism 4 is filled with oil. An oil pump 7 is installed below the expansion mechanism 4, and a bypass oil flow path 8 is connected to the suction portion 7 a of the oil pump 7. The opening on the inflow side of the bypass oil flow path 8 passes through the upper bearing member 9 that fixes the expansion mechanism 4 to the sealed container 1 and divides the inside of the sealed container 1 vertically and opens above the upper bearing member 9. ing. Further, the upper bearing member 9 is provided with an overflow pipe 10 that penetrates the upper bearing member 9 in the vertical direction and whose upper end protrudes from the opening on the inflow side of the bypass oil passage 8 by a certain distance. A terminal 11 for supplying electric power to the electric motor 3 is arranged on the upper part of the sealed container 1 so as to penetrate the sealed container 1.

  The compression mechanism 2 is a so-called scroll type, and includes a main bearing member 12 of a shaft 5 fixed to the inner wall of the sealed container 1 by welding or shrink fitting, and a fixed scroll 13 bolted on the main bearing member 12. The orbiting scroll 14 that meshes with the fixed scroll 13 is sandwiched between them. Furthermore, an anti-rotation mechanism 15 such as an Oldham ring that guides the orbiting scroll 14 so as to prevent the rotation of the orbiting scroll 14 and move in a circular orbit is provided between the orbiting scroll 14 and the main bearing member 12. The orbiting scroll 14 is moved in a circular orbit by an eccentric drive at a certain main shaft portion 5a.

  The electric motor 3 includes a stator 21 fixed to the sealed container 1 and a rotor 22 fixed to the shaft 5.

  The expansion mechanism 4 includes an upper bearing member 9, a first cylinder 32, an intermediate plate 33, a second cylinder 34, a lower bearing member 35, a first roller 36 (first piston), a second roller 37 (second piston), a first 1 vane 38, 2nd vane 39, the 1st spring 40, and the 2nd spring 41 are provided, and it has what is called a two-stage rotary type composition. The shaft 5 is rotatably supported by the upper bearing member 9 and the lower bearing member 35.

  A vane groove 34 a is formed in the second cylinder 34. The second cylinder 34 is fixed to the lower portion of the upper bearing member 9 and communicates with a discharge path 9 a that guides the refrigerant discharged to the discharge pipe 45 connected to the upper bearing member 9. An intermediate plate 33 is fixed to the lower portion of the second cylinder 34, and the first cylinder 32 is fixed to the lower portion of the intermediate plate 33. A vane groove 32 a is formed in the first cylinder 32.

  The lower bearing member 35 fixed to the lower portion of the first cylinder 32 has a suction hole 35a that is a refrigerant suction path to the first cylinder 32, and a lower surface of the lower bearing member 35 has a recess 35b. Further, a sealing plate 48 is fixed to the lower part of the lower bearing member 35, and the suction muffler 46 of the expansion mechanism 4 is formed together with the recess 35b. Further, the refrigerant sucked into the suction muffler 46 of the expansion mechanism 4 is supplied from the suction pipe 42 connected to the upper bearing member 9 to the lower bearing member 35 and the first cylinder 32, the intermediate plate 33, the second cylinder 34, and the upper bearing member. 9 is supplied through an intake passage 47 formed in the air inlet 9.

  The first roller 36 is disposed in the first cylinder 32 and is rotatably fitted to the first eccentric portion 5 b of the shaft 5. The second roller 37 is disposed in the second cylinder 34 and is rotatably fitted to the second eccentric portion 5 c of the shaft 5.

  The first vane 38 is slidably disposed in the vane groove 32 a of the first cylinder 32. The second vane 39 is slidably disposed in the vane groove 34 a of the second cylinder 34. The first spring 40 has one end in contact with the first cylinder 32 and the other end in contact with the first vane 38 to press the first vane 38 against the first roller 36. The second spring 41 has one end in contact with the second cylinder 34 and the other end in contact with the second vane 39 to press the second vane 39 against the second roller 37.

  The bypass oil passage 8 is formed of a porous resin that covers the steel pipe and the outer wall of the steel pipe, and has heat insulation properties.

  Next, the operation of the expander-integrated compressor 70 according to Embodiment 1 of the present invention will be described.

  When electric power is supplied from the terminal 11 to the electric motor 3, rotational power is generated between the stator 21 and the rotor 22, and the compression mechanism 2 is driven by the shaft 5. As a result, the compression chamber 16 formed between the fixed scroll 13 and the orbiting scroll 14 becomes smaller while moving from the outer peripheral side to the central portion. Using the volume change of the compression chamber 16, the refrigerant is sucked and compressed from the suction pipe 17 communicating with the outside of the hermetic container 1 and the suction port 13 a on the outer periphery of the fixed scroll 13, and the refrigerant becomes a predetermined pressure or higher. Is discharged from the discharge port 13 b at the center of the fixed scroll 13 by opening the reed valve 18 into the sealed container 1.

  The high-pressure refrigerant discharged into the sealed container 1 travels to the external radiator via the discharge pipe 19 while absorbing heat generated by the electric motor 3. Then, the discharged refrigerant is cooled by a radiator and sucked into the expansion mechanism 4 from the suction pipe 42.

  In the expansion mechanism 4, two first expansion chambers 43 are formed by the lower bearing member 35, the first cylinder 32, the first vane 38, the first roller 36, and the intermediate plate 33. Further, two second expansion chambers 44 are formed by the intermediate plate 33, the second cylinder 34, the second vane 39, the second roller 37, and the upper bearing member 9. The first expansion chamber 43 that is not in communication with the suction hole 35 a and the second expansion chamber 44 that is not in communication with the discharge passage 9 a are connected by a communication hole 33 a formed in the intermediate plate 33. That is, the communication hole 33a is located on the opposite side of the suction hole 35a with respect to the first vane 38 when viewed from the first expansion chamber 43 side, and the second vane 39 is sandwiched with respect to the second expansion chamber 44 side. And located on the opposite side of the discharge path 9a.

  When the high-pressure refrigerant is guided to the suction pipe 42 and flows into the suction hole 35a, the first roller 36 is pushed to rotate the shaft 5, and the volume of the first expansion chamber 43 that communicates with the suction hole 35a increases. To do. Then, when the refrigerant is sucked to a predetermined suction volume by the eccentric rotational movement of the first roller 36, the first expansion chamber 43 and the suction hole 35a are not communicated, and instead the first expansion chamber 43 communicates with the communication hole 33a. The first expansion chamber 43 and the second expansion chamber 44 are connected by the communication hole 33a. When the shaft 5 further rotates, the volume of the first expansion chamber 43 communicating with the communication hole 33a decreases, and at the same time, the volume of the second expansion chamber 44 having a larger cylinder volume starts to increase. The refrigerant moves to the second expansion chamber 44 while expanding.

  When the second roller 37 continues the eccentric rotational movement due to the rotation of the shaft 5, the pressure of the refrigerant in the second expansion chamber 44 increases and decreases to the pressure of the refrigerant on the evaporator side. The second expansion chamber 44 communicates with the discharge path 9a by further rotation of the shaft 5. When the shaft 5 further rotates, the communication with the communication hole 33a is lost, and the movement of the refrigerant from the first expansion chamber 43 to the second expansion chamber 44 is completed. Thereafter, the volume of the second expansion chamber 44 is reduced by the further rotation of the shaft 5, and the refrigerant is discharged from the discharge pipe 45 toward the evaporator through the discharge path 9a.

  The refrigerant that adiabatically expands by the expansion mechanism 4 and works on the shaft 5 is heated by the evaporator and returns to the suction pipe 17 again. Further, the power recovered during the expansion process in the expansion mechanism 4 is superimposed on the power of the electric motor 3 that drives the compression mechanism 2 by the shaft 5, and the power supplied to the electric motor 3 that drives the compression mechanism 2 is reduced.

  In the course of the above operation, the compression mechanism 2 rises in temperature together with the refrigerant in the compression process, and the expansion mechanism 4 falls in temperature together with the refrigerant in the expansion process. Since the inside of the sealed container 1 is filled with the high-temperature refrigerant discharged from the compression mechanism 2, the temperature of the oil that drops and returns to the oil reservoir 6 by lubricating the high-temperature compression mechanism 2 is increased. On the other hand, since the oil around the expansion mechanism 4 touches the low-temperature expansion mechanism 4, the temperature decreases.

  In the expander-integrated compressor 70 of the present invention, the bypass oil flow path 8 that opens to the upper part of the oil in the oil reservoir 6 is attached to the suction portion 7 a of the oil pump 7. The hot oil returning to 6 can be supplied to the oil pump 7. Thus, since the circulation of the oil supplied to the compression mechanism 2 and returning is completed at the upper part of the oil reservoir 6, the oil in the oil reservoir 6 stagnates and becomes oil in the oil reservoir 6. Temperature stratification is possible. By this temperature stratification, the periphery of the low-temperature expansion mechanism 4 below the oil reservoir 6 can be filled with low-temperature oil, and the expansion mechanism 4 is lubricated with low-temperature oil. Therefore, it can suppress that the expansion mechanism 4 is heated with oil. That is, an increase in the enthalpy of the refrigerant discharged from the expansion mechanism 4 is suppressed, and a decrease in the refrigeration capacity of the refrigeration cycle apparatus using the expander-integrated compressor 70 of the present invention can be suppressed.

  On the other hand, high-temperature oil is supplied to the high-temperature compression mechanism 2 as described above, thereby applying back pressure that presses the orbiting scroll 14 against the fixed scroll 13 to further lubricate each sliding portion. For this reason, it can suppress that the compression mechanism 2 is cooled with oil. That is, a decrease in the enthalpy of the refrigerant discharged from the compression mechanism 2 is suppressed, and a decrease in the heating capacity of the refrigeration cycle apparatus using the expander-integrated compressor 70 of the present invention can be suppressed.

  Further, in the expander-integrated compressor 70 of the present invention, the oil is stored in the oil storage section 6 so that the interface between the oil and the refrigerant is located above the upper end of the expansion mechanism 4, and the bypass oil flow path 8. Since the opening on the suction side is above the upper end of the expansion mechanism 4 and below the interface between the oil and the refrigerant, the oil circulation path to the compression mechanism 2 is the bypass oil flow path 8. Therefore, the expansion mechanism 4 is completely bypassed, so that the expansion mechanism 4 is less susceptible to the influence of high-temperature oil returning from the compression mechanism 2.

  Further, an oil provided at the top of the expansion mechanism 4 is fixed to the sealed container 1 and the oil reservoir 6 at the bottom of the sealed container 1 is partitioned into an upper part and a lower part, and the bypass oil flow path 8 communicates vertically. Since the upper bearing member 9 having the communication hole 9b is provided and the opening on the suction side of the bypass oil passage 8 opens above the upper bearing member 9 through the oil communication hole 9b of the upper bearing member 9, the compression mechanism 2 The oil that lubricates the oil is completely separated from the oil around the expansion mechanism 4 by the upper bearing member 9. Therefore, the oil that lubricates the compression mechanism 2 is held on the upper side of the upper bearing member 9, supplied directly from the oil pump 7 through the shaft 5 by the bypass oil passage 8, and again on the upper surface of the upper bearing member 9. Dripping. Thus, the upper bearing member 9 can prevent high temperature oil from touching the expansion mechanism 4. Therefore, the thermal short circuit through the oil of the compression mechanism 2 and the expansion mechanism 4 can be prevented.

  Further, since the overflow pipe 10 having one end opened upward by a certain distance from the upper bearing member 9 and the other end opened below the upper bearing member 9 is fixed through the upper bearing member 9, the oil storage portion Even if the oil located in the lower side of the upper bearing member 9 among the oil stored in 6 is discharged from the discharge pipe 45 together with the refrigerant that is used to lubricate the expansion mechanism 4 and expands, it is discharged and reduced. Only through the overflow pipe 10, the oil is automatically supplied below the upper bearing member 9. Here, the oil discharged through the expansion mechanism 4 is sucked again by the compression mechanism 2 together with the refrigerant and returns to the inside of the sealed container 1. If it does in this way, it can prevent that the quantity of high-temperature oil more than necessary is mixed in the low-temperature oil around the low-temperature expansion mechanism 4. Therefore, the thermal short circuit through the oil of the compression mechanism 2 and the expansion mechanism 4 can be prevented. Further, even when a large amount of oil is temporarily taken from the inside of the sealed container 1 to the external refrigeration cycle immediately after startup, the upper end of the overflow pipe 10 is located above the upper bearing member 9 by a certain distance. Therefore, when the oil held on the upper side of the upper bearing member 9 is lower than the opening on the upper side of the overflow pipe 10, the oil on the upper side of the upper bearing member 9 is expanded by the overflow pipe 10. 4 is prevented from flowing into the compression mechanism 2 from the oil pump 7 through the bypass oil flow path 8. Therefore, insufficient lubrication of the compression mechanism 2 due to a delay in refueling can be avoided.

  Further, since the suction portion 7a of the oil pump 7 and the bypass oil flow path 8 are connected, there is no possibility that high-temperature oil is mixed into low-temperature oil around the expansion mechanism 4. Therefore, the thermal short circuit through the oil of the compression mechanism 2 and the expansion mechanism 4 can be prevented.

  Further, the bypass oil flow path 8 is formed of a porous resin that covers the steel pipe and the outer wall of the steel pipe and has a heat insulating property. Therefore, an expansion mechanism is provided in the process of guiding high-temperature oil from the upper side of the upper bearing member 9 to the oil pump 7. It is possible to prevent heat from being exchanged with the low-temperature oil around 4 and the bypass oil passage 8.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 2 is a longitudinal sectional view of the expander-integrated compressor of the present invention.

  As shown in FIG. 2, the expander-integrated compressor 80 has substantially the same configuration as that of the first embodiment, and the same reference numerals are applied to the same functional parts. A description of the same configuration and its operation is omitted.

  The expander-integrated compressor of the present embodiment differs from the expander-integrated compressor of the first embodiment in that the overflow pipe 10 provided in the upper bearing member 9 is not provided, and the upper bearing An oil return hole 8 a that communicates the bypass oil passage 8 and the oil reservoir 6 is provided in the vicinity of the upper bearing member 9 of the bypass oil passage 8 below the member 9.

  Next, the operation of the expander-integrated compressor 80 of the present invention will be described.

  Since the expander-integrated compressor 80 of the present invention is provided with the oil return hole 8a that connects the bypass oil passage 8 and the oil reservoir 6 to the bypass oil passage 8 below the upper bearing member 9, Of the oil stored in the oil storage section 6, the oil located below the upper bearing member 9 is discharged even if it is discharged from the discharge pipe 45 together with the refrigerant that is used to lubricate the expansion mechanism 4 and expands. The oil is automatically supplied to the lower part of the upper bearing member 9 through the oil return hole 8a by the reduced amount. Here, the oil discharged through the expansion mechanism 4 is sucked again by the compression mechanism 2 together with the refrigerant and returns to the inside of the sealed container 1. If it does in this way, it can prevent that the quantity of high-temperature oil more than necessary is mixed in the low-temperature oil around the low-temperature expansion mechanism 4. Therefore, the thermal short circuit through the oil of the compression mechanism 2 and the expansion mechanism 4 can be prevented.

  Further, since the oil return hole 8 a is provided in the vicinity of the upper bearing member 9, the high temperature oil supplied from the oil return hole 8 a is temperature stratification formed by gravity among the oil around the expansion mechanism 4. Can be supplied to a relatively hot part. Therefore, since the oil supplied from the oil return hole 8a does not disturb the temperature stratification of the oil around the expansion mechanism 4, convection does not occur in the oil around the expansion mechanism 4, and the expansion mechanism 4 and the oil storage section The heat transfer coefficient on the heat transfer surface with the oil 6 can be suppressed low. Therefore, the thermal short circuit through the oil of the compression mechanism 2 and the expansion mechanism 4 can be further prevented.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 3 is a longitudinal sectional view of the expander-integrated compressor of the present invention.

  As shown in FIG. 3, the expander-integrated compressor 90 has substantially the same configuration as that of the first embodiment, and the same reference numerals are applied to the same functional parts. A description of the same configuration and its operation is omitted.

  The expander-integrated compressor of the present embodiment differs from the expander-integrated compressor of the first embodiment in that the overflow pipe 10 provided in the upper bearing member 9 is not provided, and an oil pump A conical tube expansion portion 7b having an inner diameter that is increased toward the lower side in the suction portion 7a of the air flow passage 7, and an opening on the oil pump 7 side of the bypass oil flow path 8 is located inside the tube expansion portion 7b; The opening of the oil flow path 8 on the oil pump 7 side is provided at least above the lower end of the expanded pipe portion 7b.

  Next, the operation of the expander-integrated compressor 90 of the present invention will be described.

  The expander-integrated compressor 90 of the present invention is formed with a conical pipe expanding portion 7b having an inner diameter that is enlarged toward the lower side in the suction portion 7a of the oil pump 7, and the opening on the oil pump 7 side of the bypass oil passage 8 is formed. Since the part is located inside the expanded pipe part 7b, the oil supplied through the bypass oil flow path 8 is once discharged to the expanded pipe part 7b. Since the oil discharged to the inside of the pipe expansion part 7b has a higher temperature than the oil around the expansion mechanism 4, it moves to the upper side of the pipe expansion part 7b and forms a local temperature stratification in the pipe expansion part 7b. Without being mixed with the surrounding oil, the oil is sucked by the oil pump 7 and sent to the compression mechanism 2. In addition, even if the oil located below the upper bearing member 9 among the oil stored in the oil storage unit 6 is discharged from the discharge pipe 45 together with the refrigerant that is used for lubrication of the expansion mechanism 4 and expands, A part of the oil discharged to the expanded pipe portion 7b is automatically supplied by the amount reduced. Here, the oil discharged through the expansion mechanism 4 is sucked again by the compression mechanism 2 together with the refrigerant and returns to the inside of the sealed container 1. In this way, the oil supplied from the bypass oil flow path 8 is only the amount that is sucked by the oil pump 7 and the amount that is used for lubrication of the expansion mechanism 4 and discharged from the discharge pipe 45, and the low temperature expansion. It is possible to prevent an unnecessarily high amount of hot oil from being mixed into the cold oil around the mechanism 4. Therefore, the thermal short circuit through the oil of the compression mechanism 2 and the expansion mechanism 4 can be prevented.

  Further, since the opening on the oil pump 7 side of the bypass oil passage 8 is provided at least above the lower end portion of the expanded pipe portion 7b, the oil supplied from the bypass oil flow path 8 is completely captured by the expanded portion 7b. Therefore, there is no possibility that the oil around the expansion mechanism 4 is unnecessarily mixed. Therefore, the thermal short circuit through the oil of the compression mechanism 2 and the expansion mechanism 4 can be further prevented.

  In the above embodiment, the porous oil passage 8 is made of a porous material that covers the steel pipe and the outer wall of the steel pipe. However, even if the bypass oil passage has a multi-layer structure, the number of times of heat transfer increases and results are increased. Thus, the heat transfer resistance can be increased and the same effect can be obtained.

  The expander-integrated compressor of the present invention is useful as power recovery means for recovering the expansion energy of the refrigerant in the refrigeration cycle.

The longitudinal cross-sectional view of the expander integrated compressor of the 1st Embodiment of this invention The longitudinal cross-sectional view of the expander integrated compressor of the 2nd Embodiment of this invention The longitudinal cross-sectional view of the expander integrated compressor of the 3rd Embodiment of this invention Vertical section of a conventional expander-integrated compressor Vertical section of a conventional expander-integrated compressor Cross-sectional view of a conventional expander-integrated compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Airtight container 2,102 Compression mechanism 3,103 Electric motor 4,104 Expansion mechanism 5 Shaft 5a Main shaft part 5b First eccentric part 5c Second eccentric part 6 Oil storage part 7 Oil pump 7a Suction part 7b Expanding part 8 Bypass oil Flow path 8a Oil return hole 9 Upper bearing member 9a Discharge path 9b Oil communication hole 10 Overflow pipe 11 Terminal 12 Main bearing member 13 Fixed scroll 13a Suction port 13b Discharge port 14 Revolving scroll 15 Rotation restricting mechanism 16 Compression chamber 17 Suction pipe 18 Lead Valve 19 Discharge piping 21 Stator 22 Rotor 32 First cylinder 32a Vane groove 33 Middle plate 33a Communication hole 34 Second cylinder 34a Vane groove 35 Lower bearing member 35a Suction hole 35b Recess 36 First roller (first piston)
37 Second roller (second piston)
38 1st vane 39 2nd vane 40 1st spring 41 2nd spring 42 Suction piping 43 1st expansion chamber 44 2nd expansion chamber 45 Discharge piping 46 Suction muffler 47 Suction path 48 Sealing plate 105 Thermal insulation member 60,70,80, 90 Compressor with integrated expander

Claims (12)

A sealed container;
A compression mechanism provided at an upper portion in the sealed container;
An expansion mechanism provided at a lower portion in the sealed container;
A shaft connecting the compression mechanism and the expansion mechanism;
An oil reservoir provided at the bottom of the sealed container and immersing at least a part of the expansion mechanism;
A suction part for sucking oil from the oil storage part, disposed at a lower end of the shaft and below the expansion mechanism, and connected to the oil storage part via an oil flow path provided in the shaft; An oil pump for sending oil to the compression mechanism;
A bypass oil flow path for guiding upper oil in the oil reservoir to the suction part of the oil pump;
An expander-integrated compressor equipped with a compressor. The oil surface of the oil stored in the oil storage part is located above the upper end of the expansion mechanism,
2. The expander-integrated compressor according to claim 1, wherein an opening on the inflow side of the bypass oil passage is provided above an upper end of the expansion mechanism and below the oil surface. A partition member provided on the upper side of the expansion mechanism to partition the inside of the sealed container into an upper space and a lower space, and further having an oil communication hole for vertically communicating the bypass oil flow path;
The expander-integrated compressor according to claim 1 or 2, wherein an opening on the inflow side of the bypass oil passage is provided on an upper side of the partition member. An overflow pipe having one end provided above the opening on the inflow side of the bypass oil passage and the other end provided below the partition member, and being fixed through the partition member The expander-integrated compressor according to claim 3, further comprising: 4. The expander-integrated compressor according to claim 3, wherein the bypass oil flow path is below the partition member and has an oil return hole that communicates the bypass oil flow path with the oil storage portion. . The expander-integrated compressor according to claim 5, wherein the oil return hole is provided in the vicinity of the partition member. The expander-integrated compressor according to any one of claims 1 to 6, wherein the suction portion of the oil pump and the bypass oil flow path are connected. The conical pipe expanding portion having an inner diameter downwardly expanded is formed in the suction portion of the oil pump, and the opening on the oil pump side of the bypass oil passage is positioned above the lower end of the pipe expanding portion. 4. The expander-integrated compressor according to 3. The expander-integrated compressor according to claim 8, wherein an opening on the oil pump side of the bypass oil passage is provided above a lower end of the expanded pipe portion. The expander-integrated compressor according to any one of claims 1 to 9, wherein the bypass oil passage is a heat insulating oil pipe having heat insulating properties. The expander-integrated compressor according to claim 10, wherein the heat insulating oil pipe is made of a porous material that covers a steel pipe and a pipe outer wall of the steel pipe. The expander-integrated compressor according to claim 10, wherein the heat insulating oil pipe has a multilayer structure.

Images