JP2020118092A - Scroll compressor - Google Patents

Abstract

To provide a scroll compressor which performs high-efficiency operation by reducing pressure pulsation.SOLUTION: An inner wall of a fixed spiral lap 11b of a stationary scroll 11 is formed closer to a terminal of a turning spiral lap 12b of a turning scroll 12, such that a confined volume of a first compression chamber formed from the inner wall of the fixed spiral lap and an outer wall of the turning spiral lap is made larger than a confined volume of a second compression chamber formed from an outer wall of the fixed spiral lap and an inner wall of the turning spiral lap. A volume ratio of the first compression chamber that is a ratio of the confined volume of the first compression chamber and a compression chamber volume to be dischargeable for the first compression chamber is made equal to or smaller than a volume ratio of the second compression chamber that is a ratio of the confined volume of the second compression chamber and a compression chamber volume to be dischargeable for the second compression chamber. Thus, a difference between the volume ratio of the first compression chamber and a volume ratio of the second compression chamber is eliminated or reduced, thereby reducing pressure pulsation at the time of separation.SELECTED DRAWING: Figure 1

Description

The present invention relates to a scroll compressor used for refrigeration equipment such as an air conditioner, a water heater, and a refrigerator.

Refrigerating equipment such as an air conditioner draws in the gas refrigerant evaporated in the evaporator, compresses the gas refrigerant to the pressure necessary to condense it in the condenser, and sends the high temperature and high pressure gas refrigerant into the refrigerant circuit. A scroll compressor is used.

In such a scroll compressor, the inner wall of the fixed spiral wrap of the fixed scroll is formed up to near the end of the orbiting scroll wrap of the orbiting scroll, so that the inner wall of the fixed spiral wrap and the outer wall of the orbiting spiral wrap are formed. It has been proposed that the confinement volume of the compression chamber and the confinement volume of the other compression chamber formed by the outer wall of the fixed spiral wrap and the inner wall of the swirl spiral wrap are made different to maximize the confinement volume. (For example, see Patent Document 1).

International publication 2015/162869

However, in the device described in Patent Document 1, the volume ratio of the first compression chamber formed by the inner wall of the fixed spiral wrap and the outer wall of the swirl spiral wrap is formed by the outer wall of the fixed spiral wrap and the inner wall of the swirl spiral wrap. Since it is larger than the volume ratio of the second compression chamber, the pressure of the first compression chamber at the time of separation becomes higher than the pressure of the second compression chamber, and the refrigerant flows from the first compression chamber to the second compression chamber. There is a problem that pressure pulsation occurs and performance is reduced.

The present invention solves such a problem, and an object of the present invention is to provide a scroll compressor that reduces pressure pulsation during separation and enables highly efficient operation.

In order to achieve the above object, the present invention forms the inner wall of the fixed spiral wrap of the fixed scroll up to near the end of the orbiting scroll wrap of the orbiting scroll, thereby forming the inner wall of the fixed spiral wrap and the outer wall of the orbiting spiral wrap. In the scroll compressor, the closed volume of the first compression chamber is larger than the closed volume of the second compression chamber formed by the outer wall of the fixed spiral wrap and the inner wall of the swirling spiral wrap. The volume ratio of the first compression chamber, which is the ratio of the volume of the compression chamber to the volume of the compression chamber that can be discharged from the first compression chamber, is the compression volume of the second compression chamber and the volume of the compression chamber that can discharge from the second compression chamber. The volume ratio of the second compression chamber is equal to or smaller than the volume ratio of the second compression chamber.

This eliminates or reduces the difference between the volume ratio of the first compression chamber and the volume ratio of the second compression chamber, so that pressure pulsation at the time of separation can be reduced.

According to the present invention, since the difference between the volume ratio of the first compression chamber and the volume ratio of the second compression chamber is eliminated or reduced, the pressure pulsation at the time of separation can be reduced and the efficiency can be improved.

Vertical sectional view of a scroll compressor according to Embodiment 1 of the present invention Enlarged sectional view showing the compression mechanism of the scroll compressor (A)-(d) The figure which shows the volume change of the compression chamber accompanying the orbital motion of the scroll compressor. (A) An enlarged view of the central portion of the fixed scroll in the scroll compressor, (b) A fixed spiral wrap in which the starting expansion angle of the inner wall curve of the fixed spiral wrap is smaller than the starting expansion angle of the inner wall curve of the swirling spiral wrap. Enlarged view of the center Gas injection refrigeration cycle diagram using a scroll compressor and a gas-liquid separator in Embodiment 1 of the present invention

A scroll compressor according to a first embodiment of the present invention accommodates a compression mechanism section that compresses a refrigerant, an electric mechanism section that drives the compression mechanism section, the compression mechanism section and the electric mechanism section, and a bottom section. A hermetic container having an oil storage section for storing lubricating oil is provided, the compression mechanism section has a fixed scroll, an orbiting scroll, and a rotary shaft for orbitally driving the orbiting scroll, and the fixed scroll is a circle. A plate-shaped fixed scroll end plate and a fixed spiral wrap standing on the fixed scroll end plate are provided, and the orbiting scroll is a disc-shaped orbiting scroll end plate, and a swivel standing on the wrap side end surface of the orbiting scroll end plate. A spiral wrap, wherein the fixed spiral wrap and the orbiting spiral wrap are intermeshed with each other to form a plurality of compression chambers between the fixed spiral wrap and the swirling spiral wrap, and The inner wall of the fixed scroll wrap is formed up to near the end of the swirl scroll wrap of the orbiting scroll, and the confined volume of the first compression chamber formed by the inner wall of the fixed scroll wrap and the outer wall of the swirl scroll wrap is fixed. A scroll compressor having a closed volume larger than that of a second compression chamber formed by the outer wall of the second compression chamber and the inner wall of the swirling spiral wrap,
The volume ratio, which is the ratio of the closed volume of the first compression chamber and the volume of the first compression chamber that allows the first compression chamber to discharge, allows the closed volume of the second compression chamber and the second compression chamber to discharge. It is configured to be equal to or smaller than the volume ratio of the second compression chamber, which is the volume ratio of the compression chamber.

According to the configuration of the present embodiment, the difference between the volume ratio of the first compression chamber and the volume ratio of the second compression chamber is eliminated or reduced, so that the pressure pulsation at the time of separation can be reduced.

The second embodiment of the present invention is the scroll compressor according to the first embodiment, wherein the expansion angle of the starting point of the inner wall curve of the fixed spiral wrap of the fixed scroll is set to the inner wall curve of the orbiting scroll wrap of the orbiting scroll. It is equal to or larger than the extension angle of the starting point.

According to the present embodiment, the wrap thickness of the winding start portion of the spiral wrap of the fixed scroll can be increased, so that the strength can be increased and the reliability can be improved.

The third embodiment of the present invention is a scroll compressor according to any one of the first embodiment and the second embodiment, in which a medium pressure refrigerant flows into a compression chamber during a compression process. The injection port is provided so that the refrigerant injection amount in the first compression chamber is larger or equal to that in the second compression chamber.

According to the present embodiment, it is possible to obtain the effect of increasing the refrigerant circulation amount by the refrigerant injection while suppressing the pressure pulsation at the time of separation.

The fourth embodiment of the present invention is a scroll compressor according to the third embodiment, wherein a high pressure region and a medium pressure region are formed on the back surface of the orbiting scroll, and the orbiting scroll is arbitrarily arranged from the back surface to the high pressure region. In the configuration, the load is applied by the intermediate pressure region introduced from the compression chamber, and the intermediate pressure region communicates only with the second compression chamber.

According to the present embodiment, it is possible to reduce the fluctuation in the pressing load of the orbiting scroll against the fixed scroll due to the presence or absence of refrigerant injection, and thus it is possible to maintain a stable operating state.

Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to this embodiment.

(Embodiment 1)
1 is a vertical sectional view of a scroll compressor according to a first embodiment, and FIG. 2 is an enlarged sectional view of a main part of a compression mechanism portion.

A compression mechanism section 10 for compressing the refrigerant and an electric mechanism section 20 for driving the compression mechanism section 10 are arranged in the closed container 1.

The closed container 1 includes a cylindrical body 1a extending in the up-down direction, an upper lid 1c that closes an upper opening of the body 1a, and a lower lid 1b that closes a lower opening of the body 1a. There is.

The closed container 1 is provided with a refrigerant suction pipe 2 for introducing a refrigerant into the compression mechanism unit 10 and a refrigerant discharge pipe 3 for discharging the refrigerant compressed by the compression mechanism unit 10 to the outside of the closed container 1.

The compression mechanism unit 10 includes a fixed scroll 11, an orbiting scroll 12, and a rotating shaft 13 that orbitally drives the orbiting scroll 12.

The electric mechanism unit 20 includes a stator 21 fixed to the closed casing 1 and a rotor 22 arranged inside the stator 21. The rotating shaft 13 is fixed to the rotor 22, and an eccentric shaft 13 a that is eccentric to the rotating shaft 13 is formed at the upper end of the rotating shaft 13. An oil reservoir is formed on the eccentric shaft 13a by a concave portion that opens on the upper surface of the eccentric shaft 13a.

Below the fixed scroll 11 and the orbiting scroll 12, a main bearing 30 that supports the fixed scroll 11 and the orbiting scroll 12 is provided. The main bearing 30 is formed with a bearing portion 31 that supports the rotary shaft 13 and a boss accommodating portion 32. The main bearing 30 is fixed to the closed container 1 by welding or shrink fitting.

The fixed scroll 11 includes a disk-shaped fixed scroll end plate 11a, a spiral fixed spiral wrap 11b erected on the fixed scroll end plate 11a, and an outer peripheral wall 11c erected so as to surround the fixed spiral wrap 11b. And a discharge port 14 is formed at a substantially central portion of the fixed scroll end plate 11a.

The orbiting scroll 12 includes a disk-shaped orbiting scroll end plate 12a, an orbiting spiral wrap 12b standing on the wrap side end face of the orbiting scroll end plate 12a, and a cylindrical boss portion formed on the non-wrap side end face of the orbiting scroll end plate 12a. 12c and.

The fixed spiral wrap 11b of the fixed scroll 11 and the orbiting spiral wrap 12b of the orbiting scroll 12 mesh with each other, and a plurality of compression chambers 15 are formed between the fixed spiral wrap 11b and the orbiting spiral wrap 12b.

The boss portion 12c is formed substantially in the center of the orbiting scroll end plate 12a, and is accommodated in the boss accommodating portion 32 while being inserted into the eccentric shaft 13a.

The fixed scroll 11 is fixed to the main bearing 30 with a plurality of bolts at the outer peripheral wall portion 11c. On the other hand, the orbiting scroll 12 is supported by the fixed scroll 11 via a rotation restraint member 17 such as an Oldham ring. The rotation restraint member 17 that restrains the rotation of the orbiting scroll 12 is provided between the fixed scroll 11 and the main bearing 30. Accordingly, the orbiting scroll 12 makes an orbiting motion with respect to the fixed scroll 11 without rotating.

An oil reservoir 4 for storing lubricating oil is formed at the bottom of the closed container 1, and a lower end portion 13b of the rotary shaft 13 is pivotally supported by a sub bearing 18 arranged at a lower portion of the closed container 1. ..

A positive displacement oil pump 5 is provided at the lower end of the rotary shaft 13. The oil pump 5 is arranged so that its suction port exists inside the oil storage section 4. The oil pump 5 is driven by the rotating shaft 13 and can surely suck up the lubricating oil in the oil reservoir 4 provided at the bottom of the closed container 1 regardless of the pressure condition and the operating speed, and there is no fear of running out of oil. Is eliminated.

The rotary shaft 13 is provided with a rotary shaft oil supply hole 13c extending from the lower end portion 13b of the rotary shaft 13 to the eccentric shaft 13a.

The lubricating oil sucked up by the oil pump 5 is supplied to the bearing of the auxiliary bearing 18, the bearing portion 31, and the boss portion 12c through the rotary shaft oil supply hole 13c formed in the rotary shaft 13.

The refrigerant sucked from the refrigerant suction pipe 2 is guided to the compression chamber 15 from the suction port 15a. The compression chamber 15 moves from the outer peripheral side toward the center while reducing its volume, and the refrigerant that has reached a predetermined pressure in the compression chamber 15 is discharged from the discharge port 14 provided in the center of the fixed scroll 11 to the discharge chamber 6. Is ejected. The discharge port 14 is provided with a discharge reed valve. The refrigerant which has reached a predetermined pressure in the compression chamber 15 is discharged into the discharge chamber 6 by pushing the discharge reed valve open. The refrigerant discharged into the discharge chamber 6 is led to the upper part inside the closed container 1 and discharged from the refrigerant discharge pipe 3.

In the scroll compressor according to the present embodiment, the boss accommodating portion 32 is a high pressure area A, and the outer peripheral portion of the orbiting scroll 12 in which the rotation restraining member 17 is arranged is an intermediate pressure area B. The orbiting scroll 12 is pressed against the fixed scroll 11 by applying the load in the pressure region B.

The eccentric shaft 13a is rotatably drivably inserted into the boss portion 12c via a swivel bearing 13d. An oil groove 13e is formed on the outer peripheral surface of the eccentric shaft 13a.

A ring-shaped seal member 33 is provided on the thrust surface of the main bearing 30 that receives the thrust force of the orbiting scroll end plate 12a. The seal member 33 is arranged on the outer periphery of the boss accommodating portion 32.

The closed container 1 is filled with the same high-pressure refrigerant as the refrigerant discharged into the discharge chamber 6, and the rotary shaft oil supply hole 13c is open at the upper end of the eccentric shaft 13a. The high-pressure area A is equivalent to

The lubricating oil introduced into the boss portion 12c through the rotary shaft oil supply hole 13c is supplied to the orbiting bearing 13d and the boss accommodating portion 32 by the oil groove 13e formed on the outer peripheral surface of the eccentric shaft 13a. Since the seal member 33 is provided on the outer periphery of the boss accommodating portion 32, the boss accommodating portion 32 becomes the high pressure area A.

In the orbiting scroll end plate 12a, a first oil introduction hole 51 formed in the boss portion 12c, a first oil lead-out hole 52 intermittently opened in the intermediate pressure region B, a first oil introduction hole 51, and a first oil lead-out hole. A first end plate oil communication passage 53 that communicates with the hole 52 is provided.

Further, in the orbiting scroll end plate 12a, a second oil introduction hole 61 which is intermittently opened in the intermediate pressure region B, a second oil lead-out hole 62 which is opened in the compression chamber 15, a second oil introduction hole 61 and a second oil introduction hole 61 are provided. A second end plate oil communication passage 63 that communicates with the oil lead-out hole 62 is provided. The second oil introduction hole 61 is formed on the upper surface of the orbiting scroll end plate 12a.

As described above, by forming the second oil lead-out hole 62 that intermittently connects the intermediate pressure region B and the compression chamber to the orbiting scroll 12, the intermediate pressure of the compression chamber 15 is guided to the intermediate pressure region B, and various pressures can be obtained. Even under operating conditions, the orbiting scroll 12 can be pressed against the fixed scroll 11 with a minimum required load. Therefore, the orbiting scroll 12 can be prevented from separating from the fixed scroll 11 while reducing the friction loss of the compressor, and the airtightness of the compression chamber 15 can be enhanced.

FIG. 3 is a diagram showing a change in volume of the compression chamber due to the orbiting motion of the scroll compressor, and is a state viewed from the back surface of the orbiting scroll 12 with the orbiting scroll 12 meshing with the fixed scroll 11. 3(b) is a state in which 90 degrees rotation is advanced from FIG. 3(a), FIG. 3(c) is a state in which 90 degrees rotation is further advanced from FIG. 3(b), and FIG. 3(d) is It shows a state in which the rotation further advances by 90 degrees from FIG. 3(c).

As the compression chamber 15 formed by the fixed scroll 11 and the orbiting scroll 12, a first compression chamber 15A is formed on the outer wall side of the orbiting spiral wrap 12b, and a second compression chamber 15B is formed on the inner wall side of the orbiting spiral wrap 12b. It is formed.

As shown in FIG. 3, in the state where the fixed scroll 11 and the orbiting scroll 12 are engaged with each other, by extending the outer peripheral end portion 11be of the fixed spiral wrap 11b to the same as the outer peripheral end portion 12be of the orbiting spiral wrap 12b, The position of confining the refrigerant in the compression chamber 15A and the position of confining the refrigerant in the second compression chamber 15B are shifted by about 180 degrees.

The state shown in FIG. 3A is the position where the refrigerant in the first compression chamber 15A is confined, and the state shown in FIG. 3C is the position where the refrigerant is confined in the second compression chamber 15B.

In the state shown in FIG. 3A, three first compression chambers 15A are formed, and the first compression chamber 15A1 located at the outermost periphery is in a low pressure state immediately after confining the refrigerant, and the first compression chamber 15A1. The first compression chamber 15A2 formed on the inner circumference side is in an intermediate pressure state, and the first compression chamber 15A3 formed further on the inner circumference side is in a high pressure state before discharge. The reference numeral of the second compression chamber 15B is omitted in FIG.

In the state shown in FIG. 3C, three second compression chambers 15B are formed, and the second compression chamber 15B1 located at the outermost periphery is in a low pressure state immediately after confining the refrigerant, and the second compression chamber 15B1. The second compression chamber 15B2 formed on the inner circumference side is in the intermediate pressure state, and the second compression chamber 15B3 formed on the further inner circumference side is in the discharge state and in the high pressure state.

The first compression chamber 15A1 shown in FIG. 3(a) is the closed volume of the first compression chamber 15A, and the second compression chamber 15B1 shown in FIG. 3(c) is the closed volume of the second compression chamber 15B. The suction volume of the first compression chamber 15A is made larger than the suction volume of the second compression chamber 15B by shifting the position of confining the refrigerant in the first compression chamber 15A and the position of confining the refrigerant in the second compression chamber 15B by 180 degrees. ing.

As a result, the suction volume can be maximized and the wrap height can be set low.

In the scroll compressor having the above-described configuration, the scroll compressor according to the present embodiment further includes the first compression chamber 15A with the closed volume V _1S and the first compression chamber 15A when the first compression chamber 15A can be discharged. When the volume ratio of the first compression chamber, which is the ratio of the volume V _1D of the chamber 15A, is set to V _1S /V _1D , the confined volume V _2S of the second compression chamber 15B and the second compression chamber 15B can be discharged. when the second volume ratio of the compression chamber is the ratio of the volume _{V 2D} of the second compression chamber 15B to the _V 2S _{/ V 2D,} it is constituted to satisfy the relationship of _{V 1S / V 1D ≦ V 2S} / V 2D.

That is, the volume ratio of the first compression chamber, which is the ratio of the closed volume of the first compression chamber 15A and the volume of the compression chamber in which the first compression chamber 15A can be discharged, is the same as the closed volume of the second compression chamber 15B. The second compression chamber 15B is configured to be equal to or smaller than the volume ratio of the second compression chamber, which is the ratio of the volumes of the compression chambers that can be discharged.

The term “dischargeable” here means that the compression chamber 15 communicates with the discharge port 14.

With this configuration, the pressure difference between the first compression chamber 15A and the second compression chamber 15B when separated can be reduced. Therefore, the pressure pulsation at the time of separation can be reduced, and the efficiency of the compressor can be improved. Further, in large-scale commercial air conditioners such as VRF, most of the annual operation time is occupied by operation at a low load factor. Therefore, in the conventional scroll compressor, during operation at a low load factor, overcompression occurs in the first compression chamber 15A having a large closed volume, resulting in loss.

However, according to the scroll compressor of the present embodiment, the volume ratio of the first compression chamber 15A is the same as or smaller than the volume ratio of the second compression chamber 15B as described above, so that overcompression of the first compression chamber 15A is reduced. Can maintain high efficiency throughout the year.

Further, the scroll compressor of the present embodiment is provided with a suction closed position in the first compression chamber 15A and a suction closed position in the second compression chamber 15B near the suction portion. As a result, the intake refrigerant passage can be minimized and the heat receiving loss can be reduced.

4A is an enlarged view of the central portion of the fixed spiral wrap of the present embodiment, and FIG. 4B is different from the present embodiment, in which the starting expansion angle of the inner wall curve of the fixed spiral wrap of the swirl spiral wrap is changed. It is an enlarged view of the central part of the fixed spiral wrap made smaller than the starting expansion angle of an inner wall curve.

In the scroll compressor of the present embodiment, the inner wall of the fixed spiral wrap is further formed up to near the end of the swirl spiral wrap of the orbiting scroll 12, and the volume of the first compression chamber 15A is larger than that of the second compression chamber 15B. At the same time, in order to make the volume ratio of the first compression chamber 15A smaller or equal to the volume ratio of the second compression chamber 15B, the start expansion angle of the inner wall curve of the fixed spiral wrap is set to the start expansion angle of the inner wall curve of the swirling spiral wrap. Bigger than that.

As described above, that is, by making the starting expansion angle of the inner wall curve of the fixed spiral wrap larger than the starting expansion angle of the inner wall curve of the swirling spiral wrap as shown in FIG. The wrap thickness of the wrapping start portion can be increased. Since the pressure difference between the wraps is the largest at the winding start portion of the spiral wrap and the wrap breakage is likely to occur, increasing the wrap thickness at the winding start portion as in the present embodiment reduces the strength. It greatly enhances reliability and improves reliability.

FIG. 5 is a refrigeration cycle device configured using the scroll compressor according to the first embodiment. As shown in FIG. 5, the refrigeration cycle device of this embodiment includes a compressor 91, a condenser 92, an evaporator 93, a pressure reducer 94, an injection pipe 95, and a gas-liquid separator 96.

In the gas-liquid separator 96, the refrigerant condensed in the condenser 92 is decompressed by the decompressor 94, and a part of the evaporated gas refrigerant and the liquid refrigerant are separated. The liquid refrigerant further passes through the pressure reducer 94, becomes a low pressure refrigerant, and is guided to the evaporator 93. On the other hand, the gas refrigerant separated by the gas-liquid separator 96 passes through the injection pipe 95 and is guided to the intermediate pressure chamber in the compressor 91. The injection pipe 95 may be provided with a closing valve or a pressure reducer for adjusting and stopping the injection pressure.

The refrigerant that has been further reduced in pressure to a low pressure by the pressure reducer 94 and sent to the evaporator 93 has the liquid refrigerant evaporated by heat exchange and is discharged as a gas refrigerant or a gas refrigerant mixed with a part of the liquid refrigerant. The refrigerant discharged from the evaporator 93 is guided to the refrigerant suction pipe 2 of the compressor 91 and taken into the compression mechanism portion inside the compressor.

Regarding the ratio of the refrigerant gas and the liquid refrigerant separated in the gas-liquid separator 96, the gas component increases as the pressure difference between the high pressure and the low pressure in the refrigeration cycle increases.

The scroll compressor of the present embodiment used in the refrigeration cycle apparatus that operates as described above has one injection port 54 for injecting the intermediate pressure refrigerant, one on the end plate of the fixed scroll 11, as shown in FIG. The above-mentioned injection ports 54 are provided at positions where the injection refrigerant is sent by sequentially opening to the first compression chamber 15A and the second compression chamber 15B, and at the start of opening of the injection port 54, any compression chamber is provided. It is provided at a position to be in the compression process after closing.

As a result, the refrigerant circulation amount can be increased, and the injection refrigerant is compressed without flowing backward to the suction pipe, so that highly efficient injection operation can be performed without lowering the efficiency.

Further, in the scroll compressor of the present embodiment, the amount of injection refrigerant into the first compression chamber 15A is made larger or equal to the amount of injection refrigerant into the second compression chamber 15B.

Specifically, the injection port 54 is provided at a position where the opening section to the first compression chamber 15A is longer than the opening section to the second compression chamber 15B.

Here, by injecting the intermediate pressure refrigerant into the compression chamber, the pressure in the compression chamber rises. However, in the scroll compressor of the present embodiment, as described above, the volume ratio of the first compression chamber 15A to the second compression is reduced. Since the volume ratio of the chamber 15B is smaller than or equal to the volume ratio, and the refrigerant injection amount supplied to the compression chamber is larger or equal to that of the second compression chamber 15B in the first compression chamber 15A, even during the refrigerant injection operation. The pressure pulsation can be reduced by reducing the pressure difference between the first compression chamber 15A and the second compression chamber 15B when separated.

The amount of injection into each compression chamber may be adjusted by providing an injection port 54 opening to each compression chamber and an injection port 54 opening only to the first compression chamber 15A.

Further, in the scroll compressor of the present embodiment, only the second compression chamber 15B is the compression chamber that intermittently communicates with the intermediate pressure region B. Thereby, a stable operating state can be maintained.

That is, the second compression chamber 15B has a smaller amount of refrigerant injection during the injection operation than the first compression chamber 15A, so that the load that presses the orbiting scroll 12 against the fixed scroll 11 varies greatly during the injection operation and the injection-free operation. However, as described above, if only the second compression chamber 15B is completely communicated with the intermediate pressure region B, the fluctuation in the load that presses the orbiting scroll 12 against the fixed scroll 11 is reduced, and stable operation can be realized.

The refrigerant of the present invention may be R32, carbon dioxide, or a refrigerant having a double bond between carbons.

INDUSTRIAL APPLICABILITY Since the scroll compressor of the present invention can reduce pressure pulsation and improve efficiency, it is useful for a refrigeration cycle device such as a hot water heating device, an air conditioner, a water heater, or a refrigerator.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Refrigerant suction pipe 3 Refrigerant discharge pipe 4 Oil storage part 5 Oil pump 6 Discharge chamber 10 Compression mechanism part 11 Fixed scroll 11b Fixed spiral wrap 12 Orbiting scroll 12b Swirl spiral wrap 13 Rotating shaft 13a Eccentric shaft 13b Lower end part 13c Rotating shaft Oil supply hole 13d Slewing bearing 13e Oil groove 14 Discharge port 15 Compression chamber 15A First compression chamber 15B Second compression chamber 17 Rotation restraint member 18 Sub-bearing 20 Electric mechanism part 21 Stator 22 Rotor 30 Main bearing 31 Bearing part 32 Boss accommodating part 51 First Oil Inlet Hole 52 First Oil Outlet Hole 53 First End Plate Oil Communication Path 54 Injection Port 61 Second Oil Inlet Hole 62 Second Oil Outlet Hole 63 Second End Plate Oil Communication Path 71 High Pressure Communication Path 72 High Pressure Opening 73 Balance valve 91 Compressor 92 Condenser 93 Evaporator 94 Pressure reducer 95 Injection pipe 96 Gas-liquid separator

Claims (4)

A compression mechanism part for compressing a refrigerant, an electric mechanism part for driving the compression mechanism part, and a closed container having an oil storage part for accommodating the compression mechanism part and the electric mechanism part and storing a lubricating oil at a bottom part. ,
The compression mechanism unit has a fixed scroll, an orbiting scroll, and a rotating shaft that orbitally drives the orbiting scroll,
The fixed scroll comprises a disk-shaped fixed scroll end plate, and a fixed spiral wrap standing on the fixed scroll end plate,
The orbiting scroll comprises a disc-shaped orbiting scroll end plate, and an orbiting spiral wrap standing on the wrap side end surface of the orbiting scroll end plate,
The fixed spiral wrap and the swirl spiral wrap are meshed with each other to form a plurality of compression chambers between the fixed spiral wrap and the swirl spiral wrap, and
The inner wall of the fixed spiral wrap is formed up to near the end of the swirl spiral wrap, and the confined volume of the first compression chamber formed by the inner wall of the fixed spiral wrap and the outer wall of the swirl spiral wrap is fixed. A scroll compressor having a volume larger than a closed volume of a second compression chamber formed by an outer wall of a spiral wrap and an inner wall of the swirl wrap,
The volume ratio of the first compression chamber, which is the ratio of the closed volume of the first compression chamber to the volume of the compression chamber in which the first compression chamber can be discharged, is defined by the closed volume of the second compression chamber and the volume ratio of the second compression chamber. A scroll compressor characterized by being equal to or smaller than the volume ratio of the second compression chamber, which is the ratio of the volumes of the compression chambers in which the second compression chamber can discharge. The scroll compressor according to claim 1, wherein the starting expansion angle of the inner wall curve of the fixed spiral wrap is made larger than the starting expansion angle of the inner wall curve of the swirl spiral wrap. One or more injection ports for injecting the medium pressure refrigerant are provided in the end plate of the fixed scroll, and when the opening of the injection port to the first compression chamber and the second compression chamber is started, all the compression chambers are closed. The scroll compression according to claim 1 or 2, wherein the scroll compression is provided at a position in a later compression step, and the amount of injection refrigerant into the first compression chamber is larger than the amount of injection refrigerant into the second compression chamber. Machine. The scroll compressor according to claim 3, wherein a high pressure region and a medium pressure region are formed on the back surface of the orbiting scroll, and the medium pressure region communicates only with the second compression chamber.

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