JP2010138758A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce mechanical loss and leak between laps of a fixed scroll and a turning scroll in a wide operation range and shorten operation start up time in a scroll compressor. <P>SOLUTION: The scroll compressor 50 includes a compression mechanism part 2 including the fixed scroll 3 and the turning scroll 4 and a motor driving the turning scroll 4 through a crankshaft 6, in a hermetic vessel 1. A thrust ring 30 is disposed at a back surface side of the turning scroll 4 and a ring back pressure chamber 20 is disposed at a back surface side of the thrust ring 30, an oil storage part 10 storing lubricating oil is provided in the hermetic vessel 1, and an oil supply means supplying lubricating oil in the oil storage part 10 by rotation of the crankshaft 6 is provided. The lubricating oil supplied by the oil supply means is led to a ring back pressure chamber 20 and presses the thrust ring 30. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a scroll compressor, and is particularly suitable for a refrigeration apparatus, an air conditioner, and a scroll compressor for compressing a gas such as air or nitrogen.

  2. Description of the Related Art Conventionally, there is known a scroll compressor in which a compression mechanism unit having a fixed scroll and a turning scroll inside an airtight container and an electric motor that drives the turning scroll to turn are known. In this scroll compressor, the orbiting scroll receives a force in a direction away from the fixed scroll due to the pressure in the compression chamber, and there is a risk that refrigerant leakage between the fixed scroll and the orbiting scroll increases.

  Therefore, in the low-pressure chamber type scroll compressor, in order to suppress the leakage of the refrigerant between the fixed scroll and the orbiting scroll, a thrust ring is disposed on the rear side of the orbiting scroll, and a ring provided on the rear side of the thrust ring. It has been proposed to introduce a refrigerant gas in the compression process into the back pressure chamber so that the thrust ring is pushed toward the orbiting scroll and the orbiting scroll is pressed against the fixed scroll. As an example, for example, a scroll compressor disclosed in JP 2008-38749 A (Patent Document 1) can be cited.

  Further, in the high-pressure chamber type scroll compressor, in order to suppress the leakage of the refrigerant between the fixed scroll and the orbiting scroll, a thrust ring is disposed on the rear side of the orbiting scroll, and a ring provided on the rear side of the thrust ring. It has been proposed to introduce the refrigerant gas at the discharge pressure in the sealed container into the back pressure chamber so that the thrust ring is pushed toward the orbiting scroll and the orbiting scroll is pressed against the fixed scroll. As an example, for example, a scroll compressor disclosed in Japanese Patent Application Laid-Open No. 2007-138828 (Patent Document 2) can be given.

JP 2008-38749 A JP 2007-138828 A

  In the scroll compressors of Patent Documents 1 and 2, in order to prevent leakage by pressing the orbiting scroll against the fixed scroll under all operating conditions, the pressure in the ring back pressure chamber is set to be higher in accordance with the high speed operation of the orbiting scroll. There is a need to. For this reason, there has been a problem that the pressing force of the orbiting scroll is increased during low-speed operation that does not require the pressing force of the orbiting scroll, and the mechanical loss between the orbiting scroll and the fixed scroll is increased.

  Further, the scroll compressor of Patent Document 2 has a restriction that the refrigerant gas at the discharge pressure cannot be introduced into the ring back pressure chamber on the back side of the thrust ring unless it is a high pressure chamber type. Moreover, in the scroll compressor of Patent Document 2, since the refrigerant gas having the discharge pressure in the inner space of the sealed container is introduced into the ring back pressure chamber, the operation starts until the discharge pressure in the inner space of the sealed container increases. Therefore, it takes a long time, and there is a problem that the time until shifting to the steady operation, that is, the operation start-up time becomes long.

  An object of the present invention is to provide a scroll compressor capable of reducing leakage between the laps of the orbiting scroll and the fixed scroll and mechanical loss in a wide operation range and shortening the operation start-up time.

  In order to achieve the above-described object, according to the present invention, in a sealed container, a fixed scroll and a compression mechanism having an orbiting scroll movable in the axial direction toward the fixed scroll, and the orbiting scroll via a crankshaft. A thrust ring installed on the back side of the orbiting scroll, a ring back pressure chamber provided on the back side of the thrust ring, and an oil storage part for storing lubricating oil in the internal space of the sealed container In a scroll compressor provided with oil supply means for supplying lubricating oil for the oil storage section by rotation of the crankshaft, the lubricating oil supplied by the oil supply means is guided to the ring back pressure chamber to press the thrust ring. It is to be configured to do.

A more preferable specific configuration example of the present invention is as follows.
(1) The internal space of the sealed container is held at the suction pressure.
(2) A hydraulic control valve that suppresses the pressure increase in the ring back pressure chamber is provided.
(3) The oil supply means includes an oil supply pump that is rotated by the crankshaft, and an oil supply passage that communicates the oil supply pump and the ring back pressure chamber.
(4) The crankshaft is pivotally supported via a main bearing provided on the frame, and the thrust ring is disposed with its anti-orbiting scroll side accommodated in a ring groove provided on the frame, and the ring back The pressure chamber is formed in a space in the ring groove on the back side of the thrust ring, and the oil supply passage is provided with an oil supply hole provided in the crankshaft so as to communicate with the oil supply pump, and the oil supply hole and the oil supply hole It is comprised by the communicating hole provided in the said flame | frame so that a ring back pressure chamber may be connected.
(5) A passage that communicates the oil supply hole provided in the frame and the internal space of the sealed container is provided, and a hydraulic control valve that suppresses the pressure increase in the ring back pressure chamber is provided in the passage.

  According to the scroll compressor of the present invention having such a configuration, it is possible to reduce leakage between the orbiting scroll and the fixed scroll lap and mechanical loss in a wide operation range, and to shorten the operation start-up time.

  Hereinafter, a scroll compressor according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG. 1 is a longitudinal sectional view of the scroll compressor of the present embodiment, FIG. 2 is an enlarged view of a thrust ring portion when the scroll compressor of FIG. 1 is stopped, and FIG. 3 is a thrust when the scroll compressor of FIG. 4 is an enlarged view of the ring portion, FIG. 4 is a longitudinal sectional view of the thrust ring of FIG. 1 in a single state, FIG. 5 is a longitudinal sectional view of the thrust ring in a single state, and FIG. 6 is an intermediate pressure of the scroll compressor of FIG. It is an enlarged view of a control valve part. The scroll compressor 50 according to the present embodiment is used as a scroll compressor for a refrigeration apparatus, an air conditioner, and a gas compressor such as air or nitrogen.

  The scroll compressor 50 is configured by connecting the compression mechanism unit 2 and the electric motor 8 with a crankshaft 6 and storing them in the sealed container 1.

  The sealed container 1 includes a vertically long cylindrical portion 1a and lid portions 1b and 1c that close the upper and lower surfaces of the cylindrical portion 1a. The internal space of the sealed container 1 is maintained at the suction pressure. An oil reservoir 10 for storing lubricating oil is formed at the bottom of the sealed container 1. The compression mechanism unit 2 is disposed in the upper part of the sealed container 1, the electric motor 8 is disposed in the lower part of the sealed container 1, and the crankshaft 6 is disposed perpendicularly to the central part in the sealed container 1.

  The compression mechanism part 2 is provided with the fixed scroll 3 and the turning scroll 4, and compresses the refrigerant gas which is a working fluid.

  The fixed scroll 3 includes a base plate 3a and a scroll wrap 3b provided upright on the base plate 3a. The fixed scroll 3 has a suction port 3 d at the peripheral edge, and the fixed scroll 3 has a discharge port 3 c at the center. The fixed scroll 3 is fixed to the frame 9 with fixing bolts 3d.

  The orbiting scroll 4 includes a base plate 4a, a scroll wrap 4b erected on the base plate 4a, and a boss portion 4c. The fixed scroll 3 and the orbiting scroll 4 are engaged with the respective scroll wraps 3b and 4b to form a compression chamber 22. The low-pressure refrigerant gas of the external refrigeration cycle is sucked into the sealed container 1 through the suction pipe 11, sucked into the compression mechanism portion 2 through the suction port 3 d, and compressed in the compression chamber 22.

  A slewing bearing 7 is installed inside the boss 4c, and an eccentric pin portion 6b of the crankshaft 6 is inserted into the slewing bearing 7. As the eccentric pin portion 6b rotates eccentrically, the orbiting scroll 4 is orbited.

  A frame 9 is disposed below the fixed scroll 3. The frame 9 is fixed to the sealed container 1. Between the frame 9 and the fixed scroll 3, the orbiting scroll 4 is arranged so as to be able to turn and move in the axial direction toward the fixed scroll. Main bearings 61 and 62 are installed in the central hole of the frame 9.

  In the frame 9, an intermediate pressure control valve 21 is provided in a hole that allows the intermediate pressure chamber 18 on the back side of the orbiting scroll 4 to communicate with the internal space of the sealed container 1. The intermediate pressure control valve 21 holds the pressure in the intermediate pressure chamber 18 at an intermediate pressure (intermediate pressure) between the suction pressure and the discharge pressure. The intermediate pressure chamber 18 formed on the back surface of the orbiting scroll 4 is formed in a space surrounded by the orbiting scroll 4 and the thrust ring 30.

  A ring groove 9 a for forming the ring back pressure chamber 20 is provided on the upper surface of the frame 9, and a thrust ring 30 is provided. The thrust ring 30 is arranged so that the upper surface thereof is in contact with the rear surface of the orbiting scroll 4. The thrust ring 30 is disposed with its anti-orbiting scroll side accommodated in the ring groove 9 a, whereby a space in the ring groove 9 a on the back side of the thrust ring 30 is formed as the ring back pressure chamber 20.

  The frame 9 is provided with a hydraulic control valve 40 that suppresses the pressure increase in the ring back pressure chamber 20.

  The Oldham ring 5 is disposed between the orbiting scroll 4 and the frame 9 and prevents the orbiting scroll 4 from rotating when it orbits.

  The electric motor 8 includes a rotor 8a and a stator 8b, and drives the compression mechanism unit 2 via the crankshaft 6. The electric motor 8 is positioned between the frame 9 of the compression mechanism portion 2 and the auxiliary bearing 16 that supports the lower portion of the crankshaft 6. The rotor 8a is fixed to the center portion of the crankshaft 6. The stator 8 b is disposed around the rotor 8 a and is fixed to the sealed container 1.

  The crankshaft 6 includes a main shaft portion 6a and an eccentric pin portion 6b. The crankshaft 6 connects the compression mechanism portion 2 and the electric motor 8 and has an oil supply hole for supplying lubricating oil to each sliding portion.

  The main shaft portion 6a extends vertically through the electric motor 8 and the frame 9, is supported by the main bearings 61 and 62 and the auxiliary bearing 16, and fixes the rotor 8a. An oil supply hole 17 is provided at the center of the main shaft portion 6a and the eccentric pin portion 6b so as to penetrate vertically. The main shaft portion 6s is provided with oil supply holes 63, 64 and 65 extending from the oil supply hole 17 to the main bearings 61 and 62 and the auxiliary bearing 16a, respectively.

  The eccentric pin portion 6 b is provided so as to extend upward from the upper end portion of the main shaft portion 6 a protruding upward from the frame 9. As described above, the eccentric pin portion 6b is inserted into the orbiting bearing 7 and drives the orbiting scroll 4 to orbit.

  A lower portion of the main shaft portion 6 a that protrudes downward from the electric motor 8 is supported by the auxiliary bearing portion 16. Accordingly, the upper portion of the main shaft portion 6a is supported by the main bearings 61 and 62, and the lower portion of the main shaft portion 6a is supported by the auxiliary bearing portion 16, so that the crankshaft 6 can rotate stably.

  The auxiliary bearing portion 16 includes an auxiliary bearing 16a that supports the main shaft portion 6a, an auxiliary bearing case 16b that holds the auxiliary bearing 16a, and an auxiliary bearing support member 16c that supports the auxiliary bearing case 16b. The auxiliary bearing support member 16 c is fixed to the sealed container 1.

  An oil supply pump unit 14 is installed at the lower end of the crankshaft 6. The oil supply pump unit 14 includes an oil supply pump 14a and a pump case 14b. The oil supply pump unit 14 is supported by the auxiliary bearing case 16 b and is immersed in the lubricating oil stored in the oil storage unit 10.

  When the scroll compressor is started, the electric motor 8 is operated and the orbiting scroll 4 is rotated, the refrigerant gas in the refrigeration cycle is sucked from the suction pipe 11, and the compression mechanism constituted by the fixed scroll 3 and the orbiting scroll 4. The refrigerant gas is compressed by the compression chamber 4 of the section 2. The low-temperature and low-pressure suction refrigerant gas becomes a high-temperature and high-pressure compressed refrigerant gas and is discharged into the discharge cover 24 and then discharged from the discharge pipe 12 into the external refrigeration cycle.

  Here, since the discharge gas is directly discharged from the discharge pipe 12 through the discharge cover 24, the pressure in the refrigerator oil storage unit 10 that is the internal space of the sealed container 1 is a low pressure that is the same as the suction pressure. It has become. As a case where such a so-called low pressure chamber type in which the inside of the hermetic container 1 has a suction pressure is employed, there is a case where a combustible gas is used as a working fluid. For example, hydrocarbon fluids such as propane and butane correspond to this. This is to reduce the amount of working fluid enclosed in the entire refrigeration cycle including the scroll compressor 50 from the viewpoint of safety, and the working fluid that dissolves in the lubricating oil due to the pressure drop in the oil storage unit 10 can be reduced. In the case of a working fluid used in a high pressure region such as carbon dioxide, a low pressure chamber type is used for safety of the sealed container 1.

  On the other hand, the inside of the intermediate pressure chamber 18 is at a substantially intermediate pressure (intermediate pressure) between the suction pressure and the discharge pressure.

  Note that a bypass valve 23 and a discharge hole are provided in the tooth bottom of the fixed scroll 3 in order to suppress over-compression in the compression mechanism unit 2 or to avoid liquid compression.

  When the scroll compressor 50 is started, the oil supply pump 14 a is rotated with the rotation of the crankshaft 6. As a result, the lubricating oil stored in the oil storage section 10 at the bottom of the hermetic container 1 is sucked by the positive or centrifugal oil supply pump 14a from the lubricating oil suction port provided in the pump case 14b. The oil is supplied into the boss portion 4 c of the orbiting scroll 4 through an oil supply hole 17 provided in the shaft. Thereafter, the lubricating oil is supplied to the intermediate pressure chamber 18 through the clearance of the slewing bearing 7. When the pressure in the intermediate pressure chamber 18 becomes equal to or higher than the set value, the intermediate pressure control valve 21 is opened, and the lubricating oil in the intermediate pressure chamber 18 flows out into the internal space of the sealed container 1 and is returned to the oil sump 10 to return to the intermediate pressure chamber. The pressure of 18 is maintained below a predetermined pressure.

  As shown in FIG. 6, the intermediate pressure control valve 21 includes a compressed valve spring 21a, a valve body 21b, and a valve stopper 21c having a through hole in a passage connecting the intermediate pressure chamber 18 and the inner space of the sealed container 1. It is configured with. Since the pressure in the intermediate pressure chamber 18 is increased by the oil pressure of the oil supply pump section 14, the intermediate pressure control valve 21 controls the pressure to a predetermined pressure or lower.

  On the other hand, the lubricating oil is supplied to the ring back pressure chamber 20 from the oil supply pump portion 14 through the oil supply hole 17 and the communication hole 19. The communication hole 19 is provided in the frame 9 so as to communicate the oil supply hole 17 and the ring back pressure chamber 20. The thrust ring 30 is pushed up by the hydraulic pressure introduced into the ring back pressure chamber 20 formed on the back surface of the thrust ring 30. Here, in order to allow the oil supply hole 17 and the communication hole 19 provided in the frame 9 to communicate with each other, a lateral hole 41 is formed in the crankshaft 6 in the radial direction. The communication hole 19 provided in the frame 9 has substantially the same hole area as the oil supply hole 17 and the lateral hole 41 in order to reduce fluid loss. The oil supply means for supplying the lubricating oil in the oil storage part 10 to the ring back pressure chamber 20 by the rotation of the crankshaft 6 is constituted by an oil supply pump part 14, an oil supply hole 17 in the crankshaft 6, a lateral hole 41, and a communication hole 19 in the frame 9. The

  The thrust ring 30 supports the back surface of the base plate 4a of the orbiting scroll 4, receives the hydraulic pressure of the ring back pressure chamber 20, and presses the orbiting scroll 4 to the fixed scroll 3 side.

  Since no hydraulic pressure is generated in the ring back pressure chamber 20 when the operation of the scroll compressor 50 is stopped, the thrust ring 30 enters deeply into the ring groove 9a provided in the frame 9 as shown in FIG. It is separated from the fixed scroll 3. During operation of the scroll compressor 50, hydraulic pressure is generated in the ring back pressure chamber 20, so that the pressure in the ring back pressure chamber 20 formed on the back surface of the thrust ring 30 rises as shown in FIG. Is pressed against the fixed scroll 3.

  A hydraulic control valve 40 is attached to the communication hole 19 provided in the frame 9 to control the ring back pressure chamber 20 to a predetermined pressure or less.

  As shown in FIG. 4, O-rings 31a and 31b, which are seal members, are respectively provided on the inner and outer peripheral edges of the thrust ring 30, and the thrust ring 30 and the frame 9 are interposed through the O-rings 31a and 31b. Airtightness with the ring groove is secured.

  As shown in FIG. 5, an oil groove 32 is provided in the radial direction on the upper surface of the thrust ring 30 to maintain the lubrication of the thrust ring 30 and the base plate surface of the orbiting scroll 4, and the intermediate pressure chamber 18 and the outer peripheral chamber. 33 pressures are kept the same. The lubricating oil supplied to the outer peripheral chamber 33 is supplied into the compression mechanism unit 2 together with the refrigerant sucked into the compression mechanism unit 2 and performs lubrication between the scrolls 3 and 4.

  In this embodiment, the compression container 1 includes a compression mechanism 2 having a fixed scroll 3 and a turning scroll 4, and an electric motor 8 that drives the turning scroll 4 to turn, and the turning scroll 4 faces the fixed scroll 3. A thrust ring 30 is supported on the rear surface of the orbiting scroll 4 so as to be movable in the axial direction, and has a function of pressing the orbiting scroll 4 against the fixed scroll 3 via the thrust ring 30. The hydraulic pressure from the oil supply pump 14 a is introduced into 20 and the orbiting scroll 4 is pressed via the thrust ring 30. As a result, conventionally, the operation cannot be shifted to the steady operation until the intermediate pressure rises. However, in this embodiment, the pressure in the ring back pressure chamber 20 of the back pressure of the thrust ring 30 is increased even before the intermediate pressure rises. The turning scroll 4 can be moved to the fixed scroll 3 side immediately after starting by the thrust ring 30. Therefore, it is possible to shift to the steady operation in a shorter time, and the operation start-up time can be shortened.

  Further, the pressure in the ring back pressure chamber 20 is higher than the pressure in the intermediate pressure chamber 18. That is, the pressure in the intermediate pressure chamber 18 decreases due to pressure loss when the lubricating oil passes through the clearance of the orbiting bearing 7 of the orbiting scroll 4, whereas the oil supply hole 17 of the crankshaft 6 that supplies oil to the orbiting bearing 7. This is because the pressure loss in the oil supply path to the ring back pressure chamber 20 is less reduced by increasing the pressure of the ring back pressure chamber 20 through the communication hole 19 having the same area as the above. Further, since the pressure loss due to the lubricating oil passing through the clearance of the slewing bearing 7 can be reduced, the oil supply pump unit 14 can be reduced in size and the input can be reduced.

  In order to reduce leakage between the scroll wraps, it is conceivable that a familiar layer made of a manganese phosphate film or the like is attached to the upper surface of the end plate of the orbiting scroll 4, the orbiting sliding surface, and the tooth tip surface. In this case, the running-in operation is performed, but the pressing force to the orbiting scroll 4 by the pressure of the ring back pressure chamber 20 is added to the pressing force to the orbiting scroll 4 by the intermediate pressure of the intermediate pressure chamber 18. The time required for the familiar operation can be shortened.

  Further, since the back pressure of the thrust ring 30 is generated by the lubricating oil boosted by the oil supply pump section 14, the back pressure during low speed operation decreases and the back pressure during high speed operation increases. It is possible to achieve a back pressure that is suitable at times. When the pressure in the ring back pressure chamber 20, which is the back pressure of the thrust ring 30, rises abnormally, the pressure in the ring back pressure chamber 20 is set to a predetermined pressure by the hydraulic control valve 40 provided in the communication hole 19 of the frame 9. The following are controlled. As shown in FIGS. 2 and 3, the hydraulic control valve 40 is configured to include a valve spring, a valve body, and a valve stopper having a through hole, like the pressure adjustment valve 21.

  Further, in the conventional high-pressure chamber type scroll compressor, when the discharge pressure is used as the back pressure of the thrust ring, when the discharge pressure is high, the thrust control means is attached to the thrust ring to limit the back pressure of the thrust ring. I needed it. As the clamping control means, the thrust ring is provided with a protrusion having the same height as the end plate thickness of the orbiting scroll, but there is a problem that it is difficult to manage the dimensions. In the present embodiment, the back pressure of the thrust ring 30 is controlled by the oil pressure by the oil supply pump unit 14, and the hydraulic control valve 40 is provided to control the back pressure of the thrust ring 30. No control means is required. Further, the thrust ring 30 and the orbiting scroll 4 are not required to be dimensioned and can be easily assembled.

  As described above, according to this embodiment, the operation start-up time can be shortened by supplying the lubricating oil from the oil supply pump unit 14 to the back surface of the thrust ring 30. In addition, by introducing lubricating oil from the oil supply pump unit 14 to the back surface of the thrust ring 30, it becomes possible to set a back pressure in accordance with the rotational speed and reduce mechanical loss between the scroll wrap tooth tips during low speed operation. It becomes possible to do. Furthermore, by introducing the lubricating oil from the oil supply pump section 14 into the back surface of the thrust ring 30 through the communication hole 19 provided in the frame 9, the back surface of the thrust ring 30 through the clearance of the swing bearing 7 of the orbiting scroll 4. The pressure loss can be reduced as compared with the case where the lubricating oil is introduced into the oil pump, and the power consumption of the oil supply pump unit 14 can be reduced.

It is a longitudinal cross-sectional view of the scroll compressor of one Embodiment of this invention. It is an enlarged view of the thrust ring part at the time of the operation stop of the scroll compressor of FIG. It is an enlarged view of the thrust ring part at the time of the driving | operation of the scroll compressor of FIG. It is a longitudinal cross-sectional view of the unit state of the thrust ring of FIG. It is a top view of the thrust ring of FIG. It is an enlarged view of the intermediate pressure control valve part of the scroll compressor of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Compression mechanism part, 3 ... Fixed scroll, 3a ... Base plate, 3b ... Scroll wrap, 3c ... Discharge hole, 3d ... Fixed bolt, 4 ... Revolving scroll, 4a ... Base plate, 4b ... Scroll wrap, 4c ... Boss part, 5 ... Oldham ring, 6 ... Crankshaft, 6a ... Main shaft part, 6b ... Eccentric pin part, 7 ... Slewing bearing, 8 ... Electric motor, 9 ... Frame, 9a ... Ring groove, 10 ... Oil storage part, 11 DESCRIPTION OF SYMBOLS ... Suction pipe, 12 ... Discharge pipe, 14 ... Oil pump part, 14a ... Oil pump, 14b ... Pump case, 16 ... Sub bearing part, 16a ... Sub bearing, 16b ... Sub bearing case, 16c ... Sub bearing support member, 17 DESCRIPTION OF SYMBOLS ... Oil supply hole, 18 ... Intermediate pressure chamber, 19 ... Communication hole, 20 ... Ring back pressure chamber, 21 ... Intermediate pressure control valve, 22 ... Compression chamber, 30 ... Thrust ring, 40 ... Hydraulic control valve, Scroll compressor 50.

Claims (6)

In the sealed container, a fixed scroll and a compression mechanism having a turning scroll movable in the axial direction toward the fixed scroll, and an electric motor that drives the turning scroll via a crankshaft,
Install a thrust ring on the back side of the orbiting scroll,
A ring back pressure chamber is provided on the back side of the thrust ring,
An oil storage part for storing lubricating oil is provided in the internal space of the sealed container,
In the scroll compressor provided with oil supply means for supplying lubricating oil of the oil storage part by rotation of the crankshaft,
A scroll compressor characterized in that the lubricating oil supplied by the oil supply means is guided to the ring back pressure chamber to press the thrust ring.   2. The scroll compressor according to claim 1, wherein the internal space of the sealed container is maintained at a suction pressure.   3. The scroll compressor according to claim 1, further comprising a hydraulic control valve that suppresses a pressure increase in the ring back pressure chamber.   3. The scroll compressor according to claim 2, wherein the oil supply means includes an oil pump that is rotated by the crankshaft, and an oil supply passage that communicates the oil pump and the ring back pressure chamber.   5. The crankshaft according to claim 4, wherein the crankshaft is pivotally supported via a main bearing provided on a frame, and the thrust ring is disposed with its anti-orbiting scroll side accommodated in a ring groove provided on the frame, A ring back pressure chamber is formed in a space in the ring groove on the back side of the thrust ring, and the oil supply passage is provided with an oil supply hole provided in the crankshaft so as to communicate with the oil supply pump, and the oil supply hole. And a scroll hole provided in the frame so as to communicate with the ring back pressure chamber.   The hydraulic control valve according to claim 5, wherein a passage that communicates an oil supply hole provided in the frame and an internal space of the sealed container is provided, and a hydraulic control valve that suppresses a pressure increase in the ring back pressure chamber is provided in the passage. Scroll compressor characterized by.

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