WO2020008902A1

WO2020008902A1 - Scroll compressor

Info

Publication number: WO2020008902A1
Application number: PCT/JP2019/024576
Authority: WO
Inventors: 裕文吉田; 啓晶中井; 護西部; 淳作田
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2018-07-06
Filing date: 2019-06-20
Publication date: 2020-01-09

Abstract

This scroll compressor comprises a fixed scroll (6), a turning scroll (9), a compression chamber (11) formed by meshing together the fixed scroll and the turning scroll, and a high-pressure region and back pressure chamber formed on the back surface of the turning scroll (9). Due to the turning of the turning scroll (9), the compression chamber (11) moves toward the center while changing in capacity. The scroll compressor further comprises a main discharge port (12) provided to the center part of the fixed scroll (6), a bypass discharge port (13) provided to the fixed scroll (6) so as to communicate with the compression chamber (11) partway through compression, a first channel (23) via which the high-pressure region and the back pressure chamber communicate, and a second channel (24) via which the back pressure chamber and the compression chamber intermittently communicate. The scroll compressor is configured so that due to the turning of the turning scroll (9), the communication of the second channel (24) ends before the bypass discharge port (13) and the compression chamber (11) communicate.

Description

Scroll compressor

The present disclosure relates to a scroll compressor used for an air conditioner, a refrigerator, a blower, a water heater, and the like.

スクロール A scroll compressor used in a refrigeration cycle of a conventional air conditioner or the like has, for example, a configuration shown in FIG.

That is, the sealed container 101 serving as the outer casing of the compressor has both ends closed. An electric motor 102 and a compression mechanism 103 are built in the sealed container 101.

The compression mechanism 103 mainly includes the crankshaft 104, the main bearing 105, and the compression element 106.

The electric motor 102 includes a stator 102a fixed to the inner wall surface side of the closed casing 101, and a rotor 102b rotatably supported inside the stator 102a. The crankshaft 104 is connected to the rotor 102b in a penetrating state.

オイル The oil stored in the lower part of the closed casing 101 is supplied to each sliding part of the compression mechanism 103. The oil rides on the flow of the gas compressed in the compression element 106 and is separated into gas and liquid before flowing out of the compressor from a discharge pipe 107 provided at the upper portion of the closed vessel 101. The oil is then recirculated to the lower oil sump.

The compression mechanism 103 will be described. A plurality of compression chambers 110 are formed by engaging the fixed scroll 108 and the orbiting scroll 109 on which the

spiral wraps

108a and 109a are respectively formed. By applying a constant pressure to the back pressure chamber 111 formed on the back surface of the orbiting scroll 109, the fixed scroll wrap upper surface 108b and the orbiting scroll bottom surface 109b slide in the thrust direction. The orbiting scroll 109 is connected to the crankshaft 104 having the eccentric part, and the orbiting scroll 109 is caused to orbit using the Oldham ring 112 while preventing rotation. Thus, the gas is compressed while reducing the volume of the compression chamber 110 toward the center.

The compressed gas is discharged to the outside of the compression mechanism 103 through a main discharge port 113 provided at the center of the fixed scroll 108 and a bypass discharge port 114 opened to the compression chamber 110 during compression. .

オイル The oil supplied from the oil reservoir to the back pressure chamber 111 via the internal passage 104a of the crankshaft 104 passes through the back pressure regulating valve 115 and is guided to the compression chamber 110. The back pressure adjusting valve 115 has a function of holding the orbiting scroll 109 against the fixed scroll 108 while maintaining an intermediate pressure higher than the suction pressure. The back pressure adjusting valve 115 prevents compression leakage caused by separation between the orbiting scroll 109 and the fixed scroll 108, that is, a so-called overturn phenomenon.

On the other hand, if the pressure in the back pressure chamber 111 becomes too high, the force of pressing the orbiting scroll 109 against the fixed scroll 108 becomes excessive, and the sliding loss in the thrust bearing formed by the orbiting scroll 109 and the fixed scroll 108 increases. I do. Therefore, it is necessary to appropriately maintain the pressure in the back pressure chamber 111.

Therefore, such a scroll compressor is configured to appropriately maintain the pressure in the back pressure chamber (for example, see Patent Literature 1 and Patent Literature 2).

FIG. 10 shows a scroll compressor of Patent Document 1.

では In the scroll compressor of Patent Document 1, a high-pressure area 202 and a back pressure chamber 203 are formed on the back surface of the orbiting scroll 201. A first path 204 that intermittently communicates the high-pressure region 202 with the back pressure chamber 203 and a second path 206 that intermittently communicates the back pressure chamber 203 with the compression chamber 205 are provided. Thereby, the pressure in the back pressure chamber 203 is appropriately maintained, and the compression leakage due to the overturn and the increase in the sliding loss in the thrust bearing due to the excessive pressing force are suppressed.

An appropriate amount of oil can be supplied to both the first compression chamber 205a on the wrap outer wall side and the second compression chamber 205b on the wrap inner wall side of the orbiting scroll 201, so that high efficiency and high reliability will be realized. And

The scroll compressor disclosed in Patent Document 2 has a configuration in which the second path 206 and the bypass discharge port 207 are intermittently communicated. This suppresses over-compression, particularly during low-speed, low-compression-ratio operation, suppresses an excessive rise in the pressure of the back pressure chamber 203, and reduces sliding loss in the thrust bearing.

International Publication No. 2009/130878 JP 2000-329082 A

However, in the conventional configuration, the risk that the discharge gas flowing backward from the main discharge port and the bypass discharge port to the compression chamber reaches the back pressure chamber through the second path is not considered. That is, a study on the risk that the discharge gas reaches the back pressure chamber and the back pressure chamber becomes in an excessive gas state, resulting in an increase in sliding loss in the thrust bearing, and a countermeasure against the risk are disclosed. There is no room for improvement in the efficiency of scroll compressors.

The present disclosure has been made in view of such a point, and provides a scroll compressor that exhibits high efficiency by preventing the back pressure chamber from being in an excessive gas state.

A scroll compressor according to an embodiment of the present disclosure includes a head plate, a fixed scroll having a spiral wrap rising from the head plate, an orbiting scroll, a compression chamber formed between the fixed scroll and the orbiting scroll by meshing the fixed scroll and the orbiting scroll. And a high-pressure area and a back-pressure chamber formed on the back surface of the orbiting scroll. The orbiting scroll orbits with a predetermined orbital radius along a circular orbit under the control of the rotation restricting mechanism. Due to the turning of the orbiting scroll, the compression chamber moves toward the center while changing the volume. The scroll compressor performs a series of operations of suction, compression, and discharge. The scroll compressor has a main discharge port provided at a central portion of the fixed scroll, a bypass discharge port provided to communicate with the compression scroll and the compression chamber in the middle of the fixed scroll, and a first communication port connecting the high pressure region and the back pressure chamber. And a second path intermittently connecting the back pressure chamber and the compression chamber. The communication of the second path is finished before the communication between the bypass discharge port and the compression chamber is established by the turning of the orbiting scroll.

Thereby, it is possible to prevent the back pressure chamber from being in an excessive gas state and realize high efficiency. If the bypass discharge port and the second path are designed to have a timing that simultaneously communicates with the compression chamber, the discharged gas that has flowed back through the bypass discharge port reaches the back pressure chamber through the second path. Then, the back pressure chamber becomes in an excessive gas state, which causes a decrease in the amount of oil supplied to the compression chamber. On the other hand, according to the configuration described above, the discharged gas that has flowed back through the bypass discharge port does not reach the back pressure chamber. Therefore, it is possible to prevent the back pressure chamber from being in an excessive gas state.

ため Thus, it is possible to prevent a decrease in the amount of oil supplied to the compression chamber due to an excessive gas state in the back pressure chamber. Therefore, a good lubrication state of the thrust bearing and the scroll wrap sliding portion can be realized, and high efficiency can be realized by reliable sealing of the compression chamber.

According to the present disclosure, it is possible to prevent an increase in sliding loss due to a backflow of the discharge gas and a risk of a decrease in refueling amount, and to realize a highly efficient scroll compressor.

FIG. 1 is a cross-sectional view of the scroll compressor according to the first embodiment of the present disclosure as viewed from a side. FIG. 2 is an enlarged cross-sectional view of a main part of the scroll compressor as viewed from the side. FIG. 3 is a diagram showing a cross-sectional configuration of a main part in the cross section aa of FIG. FIG. 4 is a diagram showing a cross-sectional configuration of main components in the cross section aa of FIG. FIG. 5 is a diagram showing a cross-sectional configuration of main components in a bb cross-section of FIG. FIG. 6 is a diagram showing a cross-sectional configuration of main components in a bb cross-section of FIG. FIG. 7 is a diagram showing a cross-sectional configuration of main components in a bb cross-section of FIG. FIG. 8 is a diagram showing a cross-sectional configuration of a main part in a bb cross section of FIG. FIG. 9 is a diagram showing a cross-sectional configuration of a conventional scroll compressor as viewed from the side. FIG. 10 is a cross-sectional view of a compression mechanism in a scroll compressor described in Patent Document 1.

A scroll compressor according to an embodiment of the present disclosure includes a fixed scroll having a head plate and a spiral wrap rising from the head plate, an orbiting scroll, and a fixed scroll and an orbiting scroll that are formed between the fixed scroll and the orbiting scroll. And a high-pressure area and a back-pressure chamber formed on the back of the orbiting scroll. The orbiting scroll orbits with a predetermined orbital radius along a circular orbit under the control of the rotation restricting mechanism. Due to the turning of the orbiting scroll, the compression chamber moves toward the center while changing the volume. The scroll compressor performs a series of operations of suction, compression, and discharge. The scroll compressor communicates the main discharge port provided at the center of the fixed scroll, the fixed scroll with the compression chamber, a bypass discharge port provided so as to communicate with the middle of compression, and the high pressure region and the back pressure chamber. A first path and a second path intermittently connecting the back pressure chamber and the compression chamber are provided. The communication of the second path is finished before the communication between the bypass discharge port and the compression chamber is established by the turning of the orbiting scroll.

Thereby, it is possible to prevent the back pressure chamber from being in an excessive gas state and realize high efficiency. That is, since the bypass discharge port and the second path do not communicate with the compression chamber at the same time, the discharged gas flowing backward through the bypass discharge port reaches the back pressure chamber through the second path. Excessive gas in the back pressure chamber can be prevented. Therefore, the lubrication of the thrust bearing and the scroll lap sliding part is realized by low lubrication sliding, and the compression loss is reduced by the reliable sealing of the compression chamber by ensuring the lubrication of the compression chamber. Can be. Therefore, high efficiency can be exhibited.

Further, preferably, the first path intermittently communicates the high-pressure region with the back pressure chamber, the communication timing between the first path and the back pressure chamber, and the communication between the second path and the back pressure chamber. The configuration may be different from the timing.

Thus, the first path and the second path do not communicate simultaneously with the back pressure chamber. Therefore, the oil flowing into the back pressure chamber from the first path does not cause a pressure increase in the compression chamber due to flowing into the compression chamber through the second path while the pressure is insufficiently reduced. It is possible to prevent a rise in power and maintain high efficiency.

Preferably, the oil flowing into the compression chamber and supplied to the lubrication may be compatible with the working fluid at a temperature of 50 ° C. or higher.

Therefore, even if a large amount of oil flows out of the compressor to the refrigeration cycle together with the discharge gas for some reason, the oil easily returns to the compressor together with the discharge gas. For this reason, oil depletion of the compressor can be prevented. On the other hand, compatible oils have the property of foaming under reduced pressure. In the case of a configuration in which the bypass discharge port and the second path communicate with the compression chamber at the same time, the high-temperature discharged gas that has flowed back through the bypass discharge port reaches the back pressure chamber through the second path. As a result, the temperature of the oil filled in the back pressure chamber rises and foams, resulting in a further gas excess state. On the other hand, in the present disclosure, the bypass discharge port and the second path do not communicate with the compression chamber at the same time. Thus, an excessive gas state due to foaming of the oil in the back pressure chamber can be prevented, and the oil supply to the compression chamber can be ensured. Therefore, it is possible to realize low friction sliding of the thrust bearing and the scroll lap sliding portion in a good lubricating state, and to reduce the compression loss by reliably sealing the compression chamber.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The embodiments are not intended to limit the present disclosure.

(First Embodiment)
FIG. 1 is a cross-sectional view of a scroll compressor 50 according to a first embodiment of the present disclosure as viewed from the side, and FIG. It is sectional drawing seen.

において In FIG. 1, the scroll compressor 50 includes a closed container 1 and a discharge pipe 2. The entire interior of the sealed container 1 is in a discharge pressure atmosphere communicating with the discharge pipe 2.

電動 The electric motor 3 is arranged at the center of the sealed container 1 and the compression mechanism is arranged at the upper part. A main body frame 5 of a compression mechanism that supports one end of a crankshaft 4 fixed to a rotor 3 a of the electric motor 3 is fixed to the closed casing 1. A fixed scroll 6 is attached to the main body frame 5.

主 The main shaft direction oil passage 7 provided in the crankshaft 4 has one end communicating with the oil supply pump device 8 and the other end finally communicating with the eccentric bearing 10 of the orbiting scroll 9.

The orbiting scroll 9 meshes with the fixed scroll 6 to form the compression chamber 11. The orbiting scroll 9 has a spiral orbiting scroll wrap 9a and a orbiting end plate 9b on which the orbiting scroll wrap 9a and the eccentric bearing 10 stand upright. The orbiting scroll 9 is arranged between the fixed scroll 6 and the main body frame 5.

The fixed scroll 6 includes a fixed end plate 6a and a spiral fixed scroll wrap 6b. In the center of the fixed scroll 6, a main discharge port 12 and a bypass discharge port 13 including a plurality of holes for discharging gas in the compression chamber 11 when the inside reaches a required discharge pressure during compression are arranged. ing. A suction port 14 and a suction chamber 15 which is a fluid passage until compression is started are arranged on an outer peripheral portion of the fixed scroll wrap 6b.

An eccentric shaft 17 eccentric from the main shaft 16 of the crankshaft 4 and arranged at the upper end of the crankshaft 4 is configured to engage and slide with the eccentric bearing 10 of the orbiting scroll 9.

The main shaft 16 engages and slides with the main bearing 18 of the main body frame 5. An annular seal member 19 concentric with the main bearing 18 is mounted on the main body frame 5 in a loose state. The annular seal member 19 divides a rear chamber 20 inside, which is generally at a discharge pressure atmosphere, and a back pressure chamber 21 outside, which is at an intermediate pressure atmosphere.

(4) The oil sucked up by the oil supply pump device 8 is oil that is compatible with the working fluid at a temperature of 50 ° C. or higher. The oil passes through the oil passage 7 of the crankshaft 4 and is guided to an internal space 22 formed between the orbiting scroll 9 and the eccentric shaft 17. One of the oils passes through a first path 23 provided on the back surface of the orbiting scroll 9b of the orbiting scroll 9 to a back pressure chamber 21 formed by being surrounded by the fixed scroll 6 and the main body frame 5. . The oil is guided to the compression chamber 11 through the second path 24 provided in the orbiting scroll 9 and the counterbore 25 provided on the bottom surface 6c of the fixed scroll wrap 6b.

The back pressure chamber 21 is maintained at the pressure of the compression chamber 11 during compression, which communicates with the second path 24, and presses the orbiting scroll 9 against the fixed scroll 6. Thus, the orbiting end plate 9b, the upper surface 6d of the fixed scroll wrap 6b and the fixed end plate 6a form the thrust bearing 26. The other part of the oil is discharged to the outside of the compression mechanism through the eccentric bearing 10, the back chamber 20, and the main bearing 18.

The check valve device 27 that opens and closes the outlet side of the main discharge port 12 is mounted on a plane of the fixed scroll 6 opposite to the lap side of the fixed end plate 6a. The check valve device 27 includes a reed valve 27a made of a thin steel plate and a valve retainer 27b.

下端 The lower end of the crankshaft 4 is supported by the auxiliary bearing 28 fixed by welding or shrink fitting in the closed container 1, and the crankshaft 4 rotates stably. The auxiliary bearing 28 has a journal bearing configuration, and part of the oil sucked up by the oil supply pump device 8 is supplied to the auxiliary bearing 28.

(4) The gas immediately after being compressed by the compression mechanism and discharged from the main discharge port 12 and the gas immediately before being discharged from the discharge pipe 2 to the outside of the closed container 1 are separated by the muffler 29. The gas in the discharge chamber 30 inside the muffler 29 passes through a downward gas flow path 31 provided near the outer periphery of the compression mechanism, and is guided to the upper part of the rotor 3a as shown by a dotted arrow in the figure. Here, the gas merges with the oil discharged after lubricating the main bearing 18 and the like, and reaches the lower part of the rotor 3a through a rotor passage 3b provided inside the rotor 3a. Thereafter, the mixed flow of gas and oil collides with the lower coil end of the stator 3c by centrifugal force, and is separated into gas and liquid.

ガス The gas after the gas-liquid separation is guided to the space above the stator 3c through the stator passage 3d provided on the outer periphery of the stator 3c. This space is a space separated from the space above the rotor 3a by the partition member 32. The gas passes through an upward gas flow path (not shown) provided in the compression mechanism, reaches a space above the compression mechanism, and is discharged from the discharge pipe 2 to the outside of the closed container 1.

FIGS. 3 and 4 are views showing the configuration of main parts in the cross section aa in FIG. The trajectory in which the first path 23 provided in the orbiting scroll 9 makes the orbital movement along with the rotation of the crankshaft 4 is indicated by a chain line.

FIGS. 5 to 8 are views showing the configuration of the main parts in the bb cross section in FIG. 1, and show how the orbiting scroll 9 performs the orbiting motion.

The trajectory along which the second path 24 provided in the orbiting scroll 9 orbits along with the rotation of the crankshaft 4 is indicated by a chain line. The main discharge port 12, the bypass discharge port 13, and the bottom counterbore 25 provided on the bottom surface 6c of the fixed scroll wrap are indicated by two-dot chain lines.

The first compression chamber 11a formed by the outer wall of the orbiting scroll wrap 9a and the inner wall of the fixed scroll wrap 6b, and the first compression chamber 11a formed by the inner wall of the orbiting scroll wrap 9a and the outer wall of the fixed scroll wrap 6b. It consists of two compression chambers 11b. Each of the compression chambers (the first compression chamber 11a and the second compression chamber 11b) performs a compression operation independently, and the compressed gas / liquid is discharged from the main discharge port 12 after merging at the center. When the required discharge pressure is reached during the compression, the compressed gas / liquid is supplied to the first bypass discharge port 13a provided in the middle of the compression of the first compression chamber 11a, and provided in the middle of the compression of the second compression chamber 11b. The second bypass discharge port 13b is also discharged.

The operation and operation of the scroll compressor 50 configured as described above will be described below.

および As shown in FIGS. 3 and 4, the first path 23 pivots over the annular seal member 19 shown by the dotted line. At the crank angle shown in FIG. 3, the first path 23 opens into the back chamber 20 at the discharge pressure. The internal space 22 on the upstream side of the first path 23 and the rear chamber 20 on the downstream side of the first path 23 are both in a discharge pressure atmosphere. Therefore, there is no oil flow in the first path 23.

On the other hand, at the crank angle in FIG. 4, the first path 23 opens to the back pressure chamber 21 at the intermediate pressure. Due to the pressure difference between the internal space 22 at the discharge pressure and the back pressure chamber 21 at the intermediate pressure, oil flows into the back pressure chamber 21 from the first path 23. By adjusting the ratio between the state of FIG. 3 and the state of FIG. 4 during one rotation of the crankshaft 4, the amount of oil supplied to the back pressure chamber 21 is controlled to an appropriate amount.

At the crank angle shown in FIG. 5, the first bottom counterbore 25a of the two bottom counterbores 25 and the second path 24 overlap. During this crank angle, the back pressure chamber 21 communicates with the first compression chamber 11a, and the oil in the back pressure chamber 21 flows into the first compression chamber 11a and is provided for lubrication and sealing.

At the crank angle shown in FIG. 6, the communication between the back pressure chamber 21 and the first compression chamber 11a ends, and no oil flows into the first compression chamber 11a. At this time, the first compression chamber 11a has not yet opened to the first bypass discharge port 13a.

In FIG. 7 where the crank angle is further advanced, the second bottom counterbore 25b and the second path 24 overlap. During this crank angle, the back pressure chamber 21 and the second compression chamber 11b communicate with each other, and the oil in the back pressure chamber 21 flows into the second compression chamber 11b for lubrication and sealing.

In the state shown in FIG. 8, the communication between the back pressure chamber 21 and the second compression chamber 11b ends, and no oil flows into the second compression chamber 11b. At this moment, the second compression chamber 11b starts to open to the second bypass discharge port 13b, but the second path 24 and the second bypass discharge port 13b do not simultaneously open to the second compression chamber 11b. .

As described above, the respective compression chambers (the first compression chamber 11a and the second compression chamber 11b) are not simultaneously opened to the second path 24 and the respective

bypass discharge ports

13a and 13b. Therefore, the discharged gas that has flowed back through the bypass discharge port 13 from the discharge chamber 30 in the atmosphere with the highest pressure immediately after compression does not reach the back pressure chamber 21 through the second path 24. . Thereby, it is possible to prevent the shortage of the refueling amount due to the excessive gas state of the back pressure chamber 21 that occurs when the gas reaches the back pressure chamber 21. Therefore, the lubrication of the thrust bearing 26 and the sliding portions of the fixed scroll wrap 6b and the orbiting scroll wrap 9a can be realized by a good lubrication state, and the compression chamber can be reliably supplied with lubrication to the compression chamber 11. 11 can reduce the compression loss by the reliable seal.

As described above, the first path 23 intermittently connects the internal space 22 and the back pressure chamber 21. The communication timing between the first path 23 and the back pressure chamber 21 and the communication timing between the second path 24 and the back pressure chamber 21 are shifted so that the first path 23 and the second path 24 Are not configured to communicate at the same time. As a result, the oil that has flowed into the back pressure chamber 21 from the first path 23 flows into the compression chamber 11 through the second path 24 with insufficient pressure reduction, causing an increase in the pressure of the compression chamber 11. Nothing. Therefore, it is possible to prevent a rise in compression power and maintain high efficiency.

オイル The oil used for lubrication is compatible with the working fluid at a temperature of 50 ° C or higher. Therefore, it is possible to prevent the excessive gas state due to the foaming of the oil in the back pressure chamber 21 which is seen in the conventional configuration, to prevent the depletion of the oil in the compressor, and to surely supply the oil to the compression chamber.

More specifically, oil that is compatible with the working fluid at a temperature of 50 ° C. or higher is discharged together with the discharge gas for some reason, even if a large amount of oil flows from the compressor to the refrigeration cycle. Easy to return to the compressor. For this reason, oil depletion of the compressor can be prevented.

On the other hand, the compatible oil has a property of foaming due to reduced pressure, and in the case of the conventional configuration in which the bypass discharge port 13 and the second path 24 are simultaneously connected to the compression chamber 11, the bypass discharge port 13 is The high-temperature discharged gas that has flowed back reaches the back pressure chamber 21 through the second path 24. As a result, the temperature of the oil filled in the back pressure chamber 21 rises and foams, resulting in a further gas excess state.

However, in the present disclosure, the bypass discharge port 13 and the second path 24 do not communicate with the compression chamber 11 at the same time. For this reason, an excessive gas state due to foaming of the oil in the back pressure chamber 21 can be prevented. Therefore, the lubrication of the thrust bearing 26 and the sliding portions of the fixed scroll wrap 6b and the orbiting scroll wrap 9a can be realized by a good lubrication state, and the compression chamber can be reliably supplied with lubrication to the compression chamber 11. 11 can reduce the compression loss by the reliable seal.

The volume of the compression chamber 11 at the time when the communication with the bypass discharge port 13 starts is defined as Va, and the volume of the compression chamber 11 at the time when the communication with the second path 24 ends with respect to this volume Va is defined as Vb. I do. These ratios Vb / Va should preferably be in the range of approximately 1 to 1.2.

As Vb / Va is closer to 1, the configuration is such that the bypass discharge port 13 and the second path 24 are brought as close as possible within a range where they do not communicate with the compression chamber 11 at the same time. As a result, the pressure in the compression chamber 11 increases due to the oil supplied from the back pressure chamber 21 through the second path 24, and even if the compression chamber 11 is in an over-compressed state, the communication between the second path 24 and the compression chamber 11 is established. As soon as the operation is completed, the oil can be discharged from the bypass discharge port 13. For this reason, overcompression of the compression chamber 11 can be minimized, and a decrease in compressor efficiency can be suppressed.

On the other hand, when Vb / Va exceeds 1.2, the effect of avoiding excessive compression by the bypass discharge port 13 under the low compression ratio operating condition is reduced, so that the compression power is increased and the efficiency of the compressor is likely to be reduced.

In addition, when low-viscosity oil, for example, low-viscosity oil such as viscosity grade 32 is used, if the back pressure chamber 21 is in an excessive gas state, the sealing performance of the thrust bearing 26 cannot be maintained. Refrigerant leakage from the back pressure chamber 21 to the compression chamber 11 may occur, causing a decrease in performance. Therefore, when using a low-viscosity oil, the configuration of the present disclosure exerts more effects.

Further, in the present embodiment, the two bottom counterbore 25 (the first bottom counterbore 25a and the second bottom counterbore 25b) are provided so as to communicate with the first compression chamber 11a and the second compression chamber 11b, respectively. The same effect can be obtained even if only one bottom counterbore 25 is provided so as to communicate with one of the first compression chamber 11a and the second compression chamber 11b.

As described above, according to the present disclosure, it is possible to prevent a decrease in the amount of oil supplied to the compression chamber due to an excessive gas state in the back pressure chamber, to achieve a favorable lubrication state of the thrust bearing and the scroll lap sliding portion, and High efficiency can be exhibited by a reliable seal of the compression chamber. Therefore, in addition to an air conditioner using a refrigerant such as an HFC-based refrigerant, an HCFC-based refrigerant, an HC-based refrigerant, and an HFO-based refrigerant, and an air conditioner using carbon dioxide as a natural refrigerant, It is widely applicable and useful for applications such as water heaters.

DESCRIPTION OF SYMBOLS 1 Closed container 2 Discharge pipe 3 Electric motor 3a Rotor 3b Rotor passage 3c Stator 3d Stator passage 4 Crankshaft 5 Main frame 6 Fixed scroll 6a Fixed end plate 6b Fixed scroll wrap

6c Bottom surface

6d Upper surface 7 Oil passage 8 Oil supply pump device 9 Orbiting scroll 9a Orbiting scroll wrap 9b Orbiting head plate 10 Eccentric bearing 11 Compression chamber 11a First compression chamber 11b Second compression chamber 12 Main discharge port 13 Bypass discharge port 13a First bypass discharge port 13b Second bypass discharge port 14 Suction port 15 Suction Chamber 16 Main shaft 17 Eccentric shaft 18 Main bearing 19 Annular seal member 20 Back chamber 21 Back pressure chamber 22 Internal space 23 First path 24 Second path 25 Bottom counterbore 25a First bottom counterbore 25b Second bottom counterbore 26S Strike bearing 27 check valve device

27a reed valve

27b valve retainer 28 auxiliary bearing 29 muffler 30 discharging chamber 31 downward gas flow passage 32 partition member 50 scroll compressor

Claims

A fixed scroll having a head plate and a spiral wrap rising from the head plate;
Orbiting scroll,
A compression chamber formed between the fixed scroll and the orbiting scroll by meshing the fixed scroll and the orbiting scroll;
A high-pressure area and a back-pressure chamber formed on the back surface of the orbiting scroll,
The orbiting scroll orbits at a predetermined orbital radius along a circular orbit under the control of the rotation restricting mechanism,
Due to the turning of the orbiting scroll, the compression chamber moves toward the center while changing the volume,
A scroll compressor that performs a series of operations of suction, compression, and discharge,
A main discharge port provided at the center of the fixed scroll,
The fixed scroll, the compression chamber, a bypass discharge port provided to communicate with the middle of the compression,
A first path communicating the high-pressure region and the back-pressure chamber,
A second path intermittently communicating the back pressure chamber and the compression chamber,
Further comprising
A scroll compressor configured such that communication of the second path is terminated before communication of the bypass discharge port and the compression chamber by communication of the orbiting scroll.
The first path intermittently communicates the high pressure region and the back pressure chamber,
The scroll compressor according to claim 1, wherein a communication timing between the first path and the back pressure chamber is different from a communication timing between the second path and the back pressure chamber.
3. The scroll compressor according to claim 1, wherein the oil flowing into the compression chamber and provided for lubrication has compatibility with a working fluid at a temperature of 50 ° C. or higher. 4.