WO2020162394A1

WO2020162394A1 - Scroll compressor

Info

Publication number: WO2020162394A1
Application number: PCT/JP2020/003928
Authority: WO
Inventors: 啓晶中井; 裕文吉田; 淳作田
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2019-02-08
Filing date: 2020-02-03
Publication date: 2020-08-13
Also published as: CN112567136A; JPWO2020162394A1; JP7165901B2; CN112567136B

Abstract

This scroll compressor is provided with: a fixed scroll; a turning scroll; a compression chamber; and a back pressure chamber. The compression chamber has an outer compression chamber positioned outside a second spiral wrap of the turning scroll, and an inner compression chamber positioned inside the second spiral wrap. The back pressure chamber is connected with the outer compression chamber or the inner compression chamber through the course of compression. The ratio of a suction enclosure volume of one of the compression chambers with respect to the volume of said one compression chamber when connection between said one compression chamber and the back pressure chamber is ended, is defined as a back pressure chamber closed volume ratio. The ratio of the suction enclosure volume with respect to the volume of an operation fluid dischargeable through a discharge path when the inner pressure increases and becomes equal to or more than a discharge pressure, is defined as a dischargeable volume ratio for each of the outer compression chamber and the inner compression chamber. The back pressure chamber closed volume ratio is lower than the dischargeable volume ratio of one of the compression chambers.

Description

Scroll compressor

The present disclosure relates to a scroll compressor that compresses a refrigerant gas used in, for example, a refrigerating device such as a cooling and heating air conditioner and a refrigerator, or a heat pump hot water supply device.

In a conventional scroll compressor that constitutes a refrigeration system, a back pressure chamber that presses the back surface of an orbiting scroll or a fixed scroll is formed.

An intermediate pressure hole that connects the back pressure chamber and the compression chamber is provided in the orbiting scroll or the fixed scroll so that the pressure in the back pressure chamber becomes an intermediate pressure between the suction side pressure and the discharge side pressure.

　The scroll compressor has an oil supply mechanism that supplies oil to the back pressure chamber by the pressure difference between the discharge side pressure in the closed container and the intermediate pressure in the back pressure chamber.

The scroll compressor is provided with a relief hole that connects the compression chamber and the discharge side in the closed container, and a relief valve that opens and closes the relief hole due to the pressure difference between the compression chamber and the discharge side in the closed container. There is. The relief valve is provided at a position where the relief hole and the intermediate pressure hole communicate intermittently (Patent Document 1).

Further, in a scroll compressor that constitutes a conventional refrigeration system, a flow path including an opening that connects to any one of a pair of compression chambers and an opening that connects to a back pressure chamber is provided in an orbiting scroll or a fixed scroll. ing.

The volume ratio of the compression chamber on the side where the opening on the closed space side of the flow path is connected is smaller than the volume ratio of the compression chamber on the side where the opening is not connected (Patent Document 2).

In both configurations, the pressure in the back pressure chamber is an intermediate pressure between the suction pressure and the discharge pressure. By supplying oil from the back pressure chamber to the compression chamber, the pressure in the compression chamber easily rises.

Therefore, in Patent Document 1, the intermediate compression hole and the relief hole are made to communicate with each other to prevent an overcompressed state.

Also, in Patent Document 2, by adjusting the volume ratio of the compression chamber, the increase in required power due to overcompression is suppressed.

Japanese Patent No. 3584781 Japanese Patent No. 4693984

In conventional scroll compressors, the over-compression state is prevented during the high compression ratio operation, which is the operation at a relatively high compression ratio (ratio of discharge pressure to suction pressure).

Avoiding the over-compression state is effective in reducing the pressure in the compression chamber, but at the same time, the pressure in the back pressure chamber also decreases, which does not lead to stable compression operation. Furthermore, due to the energy saving of air conditioning, refrigeration and refueling equipment, and the technology of controlling the rotation speed of the compressor, the scroll compressor is required to operate at a slower compression ratio and lower compression ratio. There is.

However, in the conventional scroll compressor, the pressing force between the orbiting scroll and the fixed scroll is lower than the pushing-back force from the compression chamber during low compression ratio operation. Therefore, there is a problem that capsizing, which is a phenomenon in which the orbiting scroll and the fixed scroll are separated from each other, occurs.

The present disclosure has been made in view of the above problems, and provides a scroll compressor that performs stable compression operation by eliminating capsizing, which is a phenomenon in which an orbiting scroll and a fixed scroll separate from each other, during low compression ratio operation. is there.

The scroll compressor of the present disclosure includes a fixed scroll having a first end plate and a first spiral wrap, an orbiting scroll having a second end plate and a second spiral wrap, the fixed scroll and the orbit. A compression chamber configured by engaging a scroll with each other, and a back pressure chamber for holding a back pressure for pressing the orbiting scroll against the fixed scroll are provided.

The compression chamber has an outer compression chamber located outside the second spiral wrap of the orbiting scroll and an inner compression chamber located inside the second spiral wrap of the orbiting scroll. ing.

The back pressure chamber communicates only with the outer compression chamber or the inner compression chamber during compression.

Each of the outer compression chamber and the inner compression chamber has a suction confined volume when the confinement of the working fluid is completed.

During compression, one of the outer compression chamber and the inner compression chamber communicates with the back pressure chamber.

The ratio of the suction closed volume of the one compression chamber to the volume of the one compression chamber when the communication between the one compression chamber and the back pressure chamber ends is defined as the back pressure chamber closed volume ratio. To do.

Regarding each of the outer compression chamber and the inner compression chamber, the ratio of the suction confined volume to the volume of the working fluid that the internal pressure rises to the discharge pressure or more and can be discharged to the discharge path is the dischargeable volume ratio.

The volume ratio when the back pressure chamber is closed is smaller than the dischargeable volume ratio of the one compression chamber.

With such a configuration, during a low compression ratio operation in which the compression ratio becomes smaller than the volume ratio when the back pressure chamber is closed, overcompression occurs in one compression chamber on the side where the back pressure chamber communicates, and the back pressure chamber is linked Is also overcompressed.

After that, the communication between the back pressure chamber and the compression chamber is closed, and the compression chamber drops to the discharge pressure when the dischargeable volume ratio is reached. On the other hand, since the back pressure chamber is separated from the compression chamber, it maintains an overcompressed state.

Therefore, it is possible to prevent the orbiting scroll from being overturned by being pressed against the fixed scroll by the pressure of the back pressure chamber that is equal to or higher than the discharge pressure.

According to the present disclosure, it is possible to provide a scroll compressor that does not separate the orbiting scroll from the fixed scroll during a low compression ratio operation and performs a stable compression operation.

FIG. 1 is a cross-sectional view of a scroll compressor according to an embodiment of the present disclosure as viewed from the side. FIG. 2 is an enlarged sectional view of a main part of a compression mechanism of the scroll compressor. FIG. 3 is a sectional view taken along the line CC in FIG. FIG. 4 is a diagram showing an opening state of a communication path with a back pressure chamber and an injection port, which accompanies the orbiting motion of the scroll compressor. FIG. 5: is a figure explaining the positional relationship of the communicating path with a back pressure chamber, and a sealing member accompanying the turning motion of the same scroll compressor. FIG. 6 is a refrigeration cycle diagram using the scroll compressor according to the embodiment of the present disclosure. FIG. 7 is a sectional view taken along the line AA of FIG. FIG. 8 is a sectional view taken along the line BB of FIG.

The scroll compressor of the present disclosure includes a fixed scroll having a first end plate and a first spiral wrap, an orbiting scroll having a second end plate and a second spiral wrap, the fixed scroll and the orbit. A scroll compressor including: a compression chamber configured to mesh with a scroll; and a back pressure chamber that holds a back pressure that presses the orbiting scroll against the fixed scroll.

With this configuration, during low compression ratio operation in which the compression ratio is smaller than the volume ratio when the back pressure chamber is closed, overcompression occurs in one of the compression chambers on the side where the back pressure chamber communicates, and on the side where the back pressure chamber communicates. The back pressure chamber is also overcompressed in conjunction with one compression chamber. After that, the communication between the back pressure chamber and the one compression chamber is closed, and when the one compression chamber reaches the dischargeable volume ratio, the pressure is reduced to the discharge pressure. On the other hand, since the back pressure chamber is separated from the compression chamber, it maintains an overcompressed state. Therefore, it is possible to prevent the orbiting scroll from being pressed against the fixed scroll by the pressure of the back pressure chamber that is equal to or higher than the discharge pressure and causing overturning.

Further, the volume ratio when the back pressure chamber is closed may be larger than the dischargeable volume ratio of the other compression chamber, which is not in communication with the back pressure chamber, of the outer compression chamber and the inner compression chamber.

As a result, the other compression chamber that is not in communication with the back pressure chamber will not be in an over-compression state that is higher than the back pressure chamber, and pressing force will be generated by the high pressure from the back pressure chamber side, resulting in stable compression operation. realizable.

Further, the suction closed volume of the outer compression chamber may be larger than the suction closed volume of the inner compression chamber, and one compression chamber on the side where the back pressure chamber communicates may be the inner compression chamber. ..

As a result, in order to bring the back pressure chamber into an over-compressed state, one of the compression chambers that communicates with the back pressure chamber by increasing the dischargeable volume ratio is an inner compression chamber with a smaller volume and an outer compression chamber with a larger volume. The dischargeable volume ratio of the chamber can be kept small.

The pressing force on the orbiting scroll is determined by the product of the area of the compression chamber projected in the pressing direction and the pressure. Therefore, in the compression chamber that creates the over-compressed state, the smaller the volume is, the less the force for canceling the pressing force is generated, and the more stable compression operation can be realized.

A discharge chamber for discharging the working fluid that has reached the discharge pressure, a discharge port provided in the central portion of the fixed scroll, and the other compression chamber that is not in communication with the back pressure chamber, are provided with the discharge port. A discharge bypass port that connects the other compression chamber and the discharge chamber may be provided earlier. Further, the discharge bypass port makes the dischargeable volume ratio of the other compression chamber not communicating with the back pressure chamber smaller than the dischargeable volume ratio of the one compression chamber communicating with the back pressure chamber. It may be configured.

By this, one compression chamber on the side communicating with the back pressure chamber is communicated with the discharge port or the discharge bypass port after the communication with the back pressure chamber is closed, is released from the overcompression state, and drops to the discharge pressure. On the other hand, the pressure in the back pressure chamber is higher than the discharge pressure because there is no pressure release point and the overcompressed state is maintained. Therefore, a pressing force from the back pressure chamber side to the fixed scroll side acts on the orbiting scroll, and the compression operation can be continued while maintaining the airtightness of the compression chamber.

Further, by providing the discharge bypass port, regardless of the wrap shape of the orbiting scroll and the wrap shape of the fixed scroll, it is possible to arbitrarily adjust the dischargeable volume ratio of only one of the inner compression chamber and the outer compression chamber, The dischargeable volume ratio of each compression chamber that realizes the present disclosure can be configured with respect to the volume ratio when the back pressure chamber is closed.

Further, the back pressure chamber when the communication between the back pressure chamber and the one compression chamber is completed is a closed space partitioned from another space having a pressure difference from the back pressure chamber. Good.

Due to this, the pressing force from the back pressure chamber side to the fixed scroll side acts on the orbiting scroll, and the compression operation can be continued while maintaining the airtightness of the compression chamber.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to these embodiments.

(Embodiment)
FIG. 1 is a cross-sectional view of a scroll compressor according to an embodiment of the present disclosure viewed from a side, and FIG. 2 is an enlarged cross-sectional view of a main part of a compression mechanism of the scroll compressor.

The operation and action of the scroll compressor according to this embodiment will be described below.

As shown in FIG. 1, a scroll compressor 91 according to the present embodiment includes a closed container 1, a compression mechanism 2 located inside the closed container 1, a motor unit 3 that drives the compression mechanism 2, and a closed container. And an oil storage portion 20 provided at the bottom of the No. 1 unit.

As shown in FIG. 2, the compression mechanism 2 has a main bearing member 11 fixed in the closed container 1 by welding, shrink fitting, etc., and bolted onto the main bearing member 11 to form an end plate (first end plate). A fixed scroll 12 in which a spiral wrap (first spiral wrap) is upright, and an orbiting scroll 13 in which a spiral wrap (second spiral wrap) is upright on an end plate (second end plate). Equipped with. The compression mechanism 2 includes a compression chamber 15 formed by engaging the fixed scroll 12 and the orbiting scroll 13 with each other, and a back pressure chamber 29 that holds pressure for pressing the orbiting scroll 13 against the fixed scroll 12.

Between the orbiting scroll 13 and the main bearing member 11, a rotation restraint mechanism 14 including an Oldham ring or the like for preventing the orbiting scroll 13 from rotating and guiding it in a circular orbital motion is provided.

The shaft 4 is rotationally driven by the motor unit 3. The shaft 4 is axially supported by the main bearing member 11, and the orbiting scroll 13 is eccentrically driven by the eccentric shaft portion 4 a at the upper end of the shaft 4.

This causes the orbiting scroll 13 to move in a circular orbit. The compression chamber 15 formed between the fixed scroll 12 and the orbiting scroll 13 moves while reducing the volume from the outer peripheral side toward the central portion. Utilizing this, the working fluid is sucked from the suction pipe 16 (see FIG. 1) communicating with the outside of the closed container 1 and the suction port 17 at the outer peripheral portion of the fixed scroll 12, and after being confined in the compression chamber 15, Compressed.

The working fluid that has reached a predetermined pressure pushes open the discharge reed valve 19 from the discharge port 18 provided in the center of the fixed scroll 12. The working fluid that has reached the discharge pressure passes through the discharge chamber 31, is discharged into the closed container 1, and is discharged from the discharge pipe 22 (see FIG. 1) to the outside of the closed container 1.

As shown in FIG. 1, a pump 25 is provided on the lower end of the shaft 4. The pump 25 is arranged so that its suction port exists inside the oil storage section 20. The pump 25 is driven simultaneously with the orbiting scroll 13. As a result, the pump 25 can reliably suck up the oil 6 in the oil reservoir 20 regardless of the pressure condition and the operating speed. Therefore, the oil will not run out.

The oil 6 sucked up by the pump 25 is supplied to the compression mechanism 2 through the oil supply hole 26 that extends vertically through the shaft 4.

If foreign matter is removed from the oil 6 with an oil filter or the like before or after sucking the oil 6 by the pump 25, the foreign matter is prevented from being mixed into the compression mechanism 2 and the reliability can be further improved. it can.

The pressure of the oil 6 guided to the compression mechanism 2 is almost the same as the discharge pressure of the scroll compressor 91 and serves as a back pressure source for the orbiting scroll 13. Further, a part of the oil 6 seeks an escape area by the supply pressure and its own weight, so that a fitting portion between the eccentric shaft portion 4a and the orbiting scroll 13 and a bearing between the shaft 4 and the main bearing member 11 are formed. After entering the portion 66 and lubricating each portion, it falls and returns to the oil storage portion 20.

3 is a sectional view taken along the line CC in FIG.

The compression chamber 15 formed by the fixed scroll 12 and the orbiting scroll 13 includes an outer compression chamber 15a located outside the wrap of the orbiting scroll 13 and an inner compression chamber 15b located inside the wrap.

The scroll compressor 91 is an asymmetric scroll compressor in which the suction closed volume of the outer compression chamber 15a and the suction closed volume of the inner compression chamber 15b are different.

Here, the suction confined volume is the volume of the compression chamber immediately after the working fluid sucked from the suction port 17 is confined. Further, the scroll compressor 91 is an asymmetric scroll compressor in which the suction closed volume of the outer compression chamber 15a is larger than the suction closed volume of the inner compression chamber 15b.

▽Because it is an asymmetric scroll compressor, the suction confined volume of the compressor as a whole increases, so the space inside the compressor can be used efficiently.

Further, the working fluid sucked from the suction port 17 can be confined in the vicinity of the suction port 17 in the outer compression chamber 15a to enter the compression process. For this reason, the low-pressure low-temperature working fluid is heated by the compression mechanism 2, and the density decrease of the working fluid can be suppressed.

The difference in the suction closed volume between the outer compression chamber 15a and the inner compression chamber 15b affects the volume ratio. The volume ratio is the ratio of the suction closed volume to the volume of the compression chamber at a certain point in the compression process. The volume ratio can be defined for each of the outer compression chamber and the inner compression chamber.

Generally, the volumes of the compression chambers when the inner compression chamber and the outer compression chamber communicate with the discharge port 18 provided in the central portion of the fixed scroll 12 are substantially equal. When the discharge port 18 is the only discharge path for the working fluid in the compression chamber, the dischargeable volume ratio of each compression chamber is determined by the suction closed volume.

Here, the dischargeable volume ratio is the ratio of the suction closed volume to the volume of the compression chamber at the time when the compression chamber becomes dischargeable, that is, when the compression chamber and the discharge chamber 31 communicate with each other. The dischargeable volume ratio can be defined for each of the outer compression chamber and the inner compression chamber.

In the present embodiment, since the suction closed volume of the outer compression chamber 15a is larger than the suction closed volume of the inner compression chamber 15b, the compression process of the outer compression chamber 15a is longer than that of the inner compression chamber 15b, and the discharge The possible volume ratio increases.

During a low compression ratio operation, which is an operation at a relatively low compression ratio, the outer compression chamber 15a is more likely to be overcompressed than the inner compression chamber 15b. Here, the compression ratio is the ratio of the discharge pressure to the suction pressure. Further, the outer compression chamber 15a has a larger area than the inner compression chamber 15b when the compression chamber is pressed and projected in the direction view. Therefore, the overcompression of the outer compression chamber 15a easily increases the force for pushing the orbiting scroll 13 away from the fixed scroll 12.

Further, at the wrap tip 13c of the orbiting scroll 13 (see FIG. 2), based on the result of measuring the temperature distribution during operation, from the winding start portion, which is the central portion, to the winding end portion, which is the outer peripheral portion, gradually The slope shape is provided so that the lap height becomes high. This makes it possible to absorb dimensional changes due to thermal expansion and prevent local sliding.

As shown in FIG. 2, the scroll compressor 91 includes a connection path 55-1 and a supply path 55-2 as an oil supply path 55 that guides oil from the oil storage section 20 to the compression chamber 15.

Further, a passage 13a formed inside the orbiting scroll 13 and a recess 12a formed on the lap surface side end plate of the fixed scroll 12 are provided as an oil supply path to the compression chamber 15. The passage 13a includes a supply passage 55-2.

One open end 55-2b of the passage 13a is formed in the wrap tip 13c and periodically opens in the recess 12a in accordance with the turning motion. The other open end 55-2a of the passage 13a is always open to the back pressure chamber 29. Thereby, the back pressure chamber 29 is intermittently communicated only with the inner compression chamber 15b and is not communicated with the outer compression chamber 15a.

Further, by positively supplying oil to the inner compression chamber 15b having a high pressure rising speed, the oil is formed next from the inner compression chamber 15b-1 (see FIG. 3) formed immediately before in the compression step. Leakage into the inner compression chamber 15b-2 (see FIG. 3) can be suppressed.

As shown in FIG. 2, the back surface 13e of the orbiting scroll 13 is provided with a seal member 78, a high-pressure region 30 for holding a working fluid having a discharge pressure, and a working fluid having a pressure intermediate between the discharge pressure and the suction pressure. A back pressure chamber 29 for holding is provided. The seal member 78 divides the inside of the seal member 78 into the high-pressure region 30 and the outside of the seal member 78 into the back pressure chamber 29.

At least one of the refueling routes is configured to pass through the back pressure chamber 29. That is, the oil supply passage 55 is composed of a connection passage 55-1 from the high pressure region 30 to the back pressure chamber 29 and a supply passage 55-2 from the back pressure chamber 29 to the inner compression chamber 15b.

Thereby, the orbiting scroll 13 is stably pressed against the fixed scroll 12 by the back pressure from the back surface 13e, the leakage of the working fluid from the back pressure chamber 29 to the compression chamber 15 is reduced, and the stable operation is performed. You can

Further, by using the seal member 78, the pressure in the high pressure region 30 and the pressure in the back pressure chamber 29 (hereinafter, back pressure) are completely separated, and the pressure applied from the back surface of the orbiting scroll 13 can be stably applied. You can control.

In addition, by providing the connection path 55-1 from the high pressure region 30 to the back pressure chamber 29, the oil 6 is applied to the sliding portion of the rotation restraint mechanism 14 and the thrust sliding portion of the fixed scroll 12 and the orbiting scroll 13. Can be supplied.

Further, by providing the supply passage 55-2 from the back pressure chamber 29 to the inner compression chamber 15b, the amount of oil supplied to the inner compression chamber 15b can be positively increased, and the leakage loss in the inner compression chamber 15b can be suppressed. ..

Further, one opening end 55-1b of the connection path 55-1 is formed on the back surface 13e of the orbiting scroll 13, the sealing member 78 is moved in and out, and the other opening end 55-1a is always opened in the high pressure region 30. Let Thereby, intermittent refueling and adjustment of back pressure can be realized.

First, I will explain intermittent refueling.

FIG. 5 is a diagram illustrating the positional relationship between the communication passage with the back pressure chamber and the seal member, which accompanies the orbiting motion of the scroll compressor.

FIG. 5 shows the states of (I) 0° to 90°, (II) 90° to 180°, (III) 180° to 270°, and (IV) 270° to 360° by shifting the phase by 90°. Showing.

That is, (II) of FIG. 5 is a state in which the shaft 4 is rotated 90 degrees from (I) of FIG. 5, and (III) of FIG. 5 is a state of being further rotated 90 degrees from (II) of FIG. 5(IV) shows a state further rotated by 90 degrees from FIG. 5(III), and FIG. 5(I) shows a state further rotated by 90 degrees from FIG. 5(IV).

As shown in FIG. 5, one opening end 55-1b of the connection path 55-1 is located on the rear surface 13e of the orbiting scroll 13. The back surface 13e of the orbiting scroll 13 is partitioned by a seal member 78 into an inner high pressure region 30 and an outer back pressure chamber 29.

In the state of (II) of FIG. 5, one open end 55-1b is open to the back pressure chamber 29 outside the seal member 78. Therefore, the back pressure chamber 29 and the high pressure region 30 communicate with each other. As a result, the oil 6 is supplied from the high pressure region 30 to the back pressure chamber 29.

On the other hand, in the states (I), (III), and (IV) of FIG. 5, the opening end 55-1b opens inside the seal member 78. Therefore, the back pressure chamber 29 does not communicate with the high pressure region 30. Therefore, the oil 6 is not supplied from the high pressure region 30 to the back pressure chamber 29.

That is, one open end 55-1b of the connecting path 55-1 moves back and forth between the high pressure region 30 and the back pressure chamber 29, and the open ends 55-1a and 55-1b on both sides of the connecting path 55-1 are connected. The oil 6 is supplied to the back pressure chamber 29 only when there is a pressure difference therebetween. As a result, the amount of refueling is adjusted by the time rate at which the one open end 55-1b travels across the seal member 78. Therefore, the passage diameter of the connection passage 55-1 can be configured to be 10 times or more the size of the oil filter.

In addition, since there is no risk of foreign matter being caught in the passage to be blocked, a stable back pressure can be applied, and at the same time, good lubrication of the thrust sliding portion and the rotation restraint mechanism 14 can be maintained, resulting in high efficiency. High reliability can be realized.

In the above description, the case where the other open end 55-1a is always in the high pressure region 30 and the one open end 55-1b moves between the high pressure region 30 and the back pressure chamber 29 is described as an example. did. The present disclosure is not limited to this example. For example, the other open end 55-1a moves back and forth between the high pressure region 30 and the back pressure chamber 29, and one open end 55-1b is always in the back pressure chamber 29. Even in such a case, a pressure difference occurs between the open ends 55-1a and 55-1b, so that intermittent oil supply can be realized and the same effect can be obtained.

Next, I will explain the adjustment of back pressure.

FIG. 4 is a diagram showing a communication path with the back pressure chamber and an opening state of the injection port, which accompanies the orbiting motion of the scroll compressor.

FIG. 4 shows a state in which the fixed scroll 12 and the orbiting scroll 13 are meshed with each other and seen from the back surface 13e of the orbiting scroll 13, and the phases are shifted by 90 degrees. Similar to FIG. 5, FIG. 4 shows the states of (I) 0° to 90°, (II) 90° to 180°, (III) 180° to 270°, and (IV) 270° to 360°. There is.

That is, (II) of FIG. 4 shows the shaft 4 rotated 90 degrees from (I) of FIG. 4, (III) of FIG. 4 further rotates 90 degrees from (II) of FIG. (IV) of FIG. 4 shows a state further rotated by 90 degrees from (III) of FIG. 4, and (I) of FIG. 4 shows a state of further rotated by 90 degrees from (IV) of FIG.

The state shown in (I) of FIG. 4 is the position where the outer compression chamber 15a confines the working fluid, and the state shown in (III) of FIG. 4 is the position where the inner compression chamber 15b confines the working fluid.

In the state shown in FIG. 4(I), two outer compression chambers 15a are formed. The outer compression chamber 15a located on the outer peripheral side is in a low pressure state immediately after confining the working fluid, and the outer compression chamber 15a located on the inner peripheral side is in an intermediate pressure state.

In the state shown in (II) of FIG. 4, the outer compression chamber 15a formed on the inner peripheral side is in a high pressure state before discharge.

In the state shown in (III) of FIG. 4, two inner compression chambers 15b are formed, and the inner compression chamber 15b located on the outer peripheral side is in a low pressure state immediately after confining the working fluid and is on the inner peripheral side. The located inner compression chamber 15b is in an intermediate pressure state.

In the state shown in (IV) of FIG. 4, the inner compression chamber 15b formed on the inner peripheral side is in a high pressure state before discharge.

First, the case of high compression ratio operation will be explained.

In the state of (IV) of FIG. 4, one opening end 55-2b opens in the recess 12a. Therefore, the inner compression chamber 15b communicates with the back pressure chamber 29. During the high compression ratio operation, the oil 6 is supplied from the back pressure chamber 29 to the inner compression chamber 15b through the supply passage 55-2 and the passage 13a (see FIG. 2).

The recess 12a is provided at a position where one opening end 55-2b is opened immediately after the inner compression chamber 15b traps the sucked working fluid (also referred to as suction refrigerant) (see (IV) in FIG. 4). ). In other words, by one opening end 55-2b, the oil supply path is provided at a position that opens into the inner compression chamber 15b in the compression process after the suction refrigerant is closed. Therefore, the pressure of the back pressure chamber 29 while communicating with the inner compression chamber 15b becomes substantially equal to the pressure of the inner compression chamber 15b.

On the other hand, in the states of (I), (II), and (III) of FIG. 4, one opening end 55-2b does not open in the recess 12a. Therefore, the oil 6 is not supplied from the back pressure chamber 29 to the inner compression chamber 15b. Further, the pressure in the back pressure chamber 29 is not affected by the inner compression chamber 15b.

Further, as described above, in the state of (II) of FIG. 5 corresponding to (II) of FIG. 4, the back pressure chamber 29 and the high pressure region 30 communicate with each other. As a result, the pressure in the back pressure chamber 29 becomes equal to the pressure in the high pressure region 30, that is, the discharge pressure.

That is, during the high compression ratio operation, the back pressure chamber 29 can be adjusted to an intermediate pressure state between the suction pressure and the discharge pressure, and this pressure functions as the pressing force against the orbiting scroll during the low compression ratio operation.

Next, the case of low compression ratio operation will be explained.

During the low compression ratio operation, in the state of (IV) of FIG. 4, the pressure of the inner compression chamber 15b, which communicates with the back pressure chamber 29 and is located on the outer peripheral side, increases to the discharge pressure or more, and at the same time, the back pressure chamber 29 also The pressure exceeds the discharge pressure.

In the state of (IV) of FIG. 5, the back pressure chamber 29 is not in communication with the high pressure region 30, and the space formed by the inner compression chamber 15b and the back pressure chamber 29 is a closed space. Therefore, the back pressure chamber 29 is in a higher pressure state than the high pressure region 30 which is equal to the discharge pressure.

When the compression process further progresses, and the open end 55-2b communicating the back pressure chamber 29 and the inner compression chamber 15b comes out of the recess 12a, the back pressure chamber 29 becomes an independent closed space. Therefore, the pressure in the back pressure chamber 29 does not depend on the pressure in the inner compression chamber 15b and the pressure in the high pressure region 30. When the compression in the inner compression chamber 15b progresses to the dischargeable volume ratio or more, the working fluid in the compression chamber is discharged into the discharge chamber 31 and is reduced to the discharge pressure. On the other hand, the pressure in the back pressure chamber 29 continues until the back compression chamber 29 communicates with the inner compression chamber 15b or the high pressure region 30 again in the overcompressed state when separated from the inner compression chamber 15b.

That is, during the low compression ratio operation, only the back pressure chamber 29 maintains a pressure state higher than the discharge pressure in the states of (I) of FIG. 4 and (I) of FIG. 5, and this pressure is Functions as a pressing force against the orbiting scroll.

In addition to the discharge port 18, a discharge bypass port 21 (see FIG. 2) is provided in the scroll compressor 91 as a passage for guiding the working fluid compressed in the compression chamber 15 to the discharge chamber 31.

Like the discharge port 18, the discharge bypass port 21 is equipped with a reed valve. When the pressure in the compression chamber 15 reaches the pressure in the discharge chamber 31, the reed valve is pushed open and the working fluid is discharged to the discharge chamber 31. When the pressure in the compression chamber 15 is less than the pressure in the discharge chamber 31, the reed valve is closed and the backflow of the working fluid from the discharge chamber 31 to the compression chamber 15 is suppressed.

However, as a condition that the discharge bypass port 21 realizes the above-mentioned function, the discharge bypass port 21 needs to exist at a position communicating with the compression chamber 15. The discharge bypass port 21 is a fixed passage provided in the end plate of the fixed scroll 12.

With the compression operation, the compression chamber 15 moves toward the center while reducing its volume, and only when the compression chamber 15 reaches the position where it communicates with the discharge port 18 or the discharge bypass port 21, the working fluid of the compression chamber 15 is reached. Can be discharged to the discharge chamber 31.

The discharge bypass port 21 is provided so as to connect the compression chamber 15 and the discharge chamber 31 before being connected to the discharge chamber 31 by the discharge port 18 in the compression process.

As shown in FIG. 4, the scroll compressor 91 is provided with a discharge bypass port 21a communicating with the outer compression chamber 15a and a discharge bypass port 21b communicating with the inner compression chamber 15b, respectively. The timing to do is shifted.

The discharge bypass port 21a does not communicate with the outer compression chamber 15a in the state of (I) of FIG. 4, and does not communicate with the outer compression chamber 15a located on the outer peripheral side in the states of (II) to (IV) of FIG. It is provided at the position where it communicates.

The discharge bypass port 21b does not communicate with the inner compression chamber 15b in the state of (IV) of FIG. 4, and does not communicate with the inner compression chamber 15b located on the outer peripheral side in the states of (I) to (III) of FIG. It is provided at the position where it communicates.

The outer compression chamber 15a completes the suction process at the timing of (I) in FIG. 4, and the outer compression chamber 15a is confined. In (II) of FIG. 4 where the compression process has advanced 90°, the outer compression chamber 15a is already in communication with the discharge bypass port 21a. In this case, the dischargeable volume ratio of the outer compression chamber 15a is determined by the ratio of the suction closed volume of the outer compression chamber 15a to the compression chamber volume at the timing when the outer compression chamber 15a communicates with the discharge bypass port 21a, and is substantially determined. , Does not depend on the communication timing with the discharge port 18.

On the other hand, the inner compression chamber 15b completes the suction process at the timing of (III) in FIG. 4, and the inner compression chamber 15b is confined. In (IV) of FIG. 4 where the compression process has advanced 90°, the inner compression chamber 15b is not in communication with the discharge bypass port 21b. In (I) of FIG. 4 further advanced by 90°, the inner compression chamber 15b communicates with the discharge bypass port 21b. Further, at the timing of (IV) in FIG. 4, the inner compression chamber 15b communicates with the back pressure chamber 29 via the supply passage 55-2 and the passage 13a.

Also in this case, the dischargeable volume ratio of the inner compression chamber 15b is determined by the communication timing with the discharge bypass port 21b. The dischargeable volume ratio of the inner compression chamber 15b communicating with the back pressure chamber 29 is larger than the back pressure chamber closed volume ratio and the dischargeable volume ratio of the outer compression chamber 15a.

Here, the volume ratio when the back pressure chamber is closed means the compression chamber on the side where the back pressure chamber 29 communicates, that is, in the inner compression chamber 15b, the communication between the back pressure chamber 29 and the inner compression chamber 15b in the middle of compression is completed. This is the ratio of the intake confined volume to the volume of the inner compression chamber 15b on the outer peripheral side at the time of (that is, the timing immediately after (IV) in FIG. 4).

With such a configuration, during low compression ratio operation, even if the pressure of the compression chamber 15 reaches the discharge pressure at an early timing, the outer compression chamber 15a having a large projected area does not overcompress and operates to the discharge chamber 31. Fluid can be discharged.

On the other hand, over-compression occurs in the inner compression chamber 15b, and the pressure is transmitted to the back pressure chamber 29 to increase the pressing force of the orbiting scroll 13. After the communication between the inner compression chamber 15b and the back pressure chamber 29 is completed, the pressure of the back pressure chamber 29 in the over-compressed state is maintained.

On the other hand, overcompression of the inner compression chamber 15b is eliminated by communication with the discharge bypass port 21b. As a result, a strong pressing force is applied to the back surface 13e of the orbiting scroll while suppressing the force from the compression chamber 15 side that acts in the direction of separating the orbiting scroll 13 from the fixed scroll 12, and the orbiting scroll 13 is stabilized on the fixed scroll 12. The compression operation can be continued while pressing it.

Next, a refrigeration cycle device using the scroll compressor 91 will be described.

FIG. 6 is a refrigeration cycle diagram using the scroll compressor according to the embodiment of the present disclosure.

As shown in FIG. 6, the refrigeration cycle device includes a scroll compressor 91, a condenser 92, an evaporator 93, two pressure reducers 94, an injection pipe 95, and a gas-liquid separator 96. The scroll compressor 91, the condenser 92, the upstream pressure reducer 94a, the gas-liquid separator 96, and the downstream pressure reducer 94b are connected in an annular shape by pipes. The injection pipe 95 connects the gas-liquid separator 96 and the scroll compressor 91.

The working fluid (hereinafter, also referred to as a refrigerant) condensed in the condenser 92 is depressurized to an intermediate pressure by the depressurizer 94a on the upstream side and flows into the gas-liquid separator 96. The gas-liquid separator 96 separates the intermediate-pressure refrigerant into a gas phase component (gas refrigerant) and a liquid phase component (liquid refrigerant). The intermediate-pressure liquid refrigerant passes through the pressure reducer 94 on the further downstream side, becomes a low-pressure refrigerant, and flows into the evaporator 93.

The liquid refrigerant flowing into the evaporator 93 evaporates by heat exchange and is discharged as a gas refrigerant or a gas refrigerant partially mixed with the liquid refrigerant. The refrigerant discharged from the evaporator 93 flows into the compression chamber 15 of the scroll compressor 91.

On the other hand, the intermediate-pressure gas refrigerant separated by the gas-liquid separator 96 passes through the injection pipe 95 and is injected (injected) into the compression chamber 15 in the scroll compressor 91. The injection pipe 95 may be provided with means for adjusting and stopping the injection pressure, such as a closing valve or a pressure reducer 94.

In the compression process of compressing the low-pressure refrigerant flowing from the evaporator 93, the scroll compressor 91 injects the intermediate-pressure refrigerant of the gas-liquid separator 96 into the compression chamber 15 to compress the refrigerant and discharge the high-temperature high-pressure refrigerant into the discharge pipe. 22 (see FIG. 1) to the condenser 92.

The ratio of the gas phase component and the liquid phase component of the refrigerant separated by the gas liquid separator 96 will be described.

The gas phase component increases as the pressure difference between the inlet side pressure and the outlet side pressure of the upstream expansion valve (pressure reducer 94a) increases. Further, the smaller the degree of supercooling of the refrigerant at the outlet of the condenser 92 or the greater the degree of dryness, the more the gas phase component.

On the other hand, the amount of the refrigerant sucked by the scroll compressor 91 through the injection pipe 95 increases as the intermediate pressure increases. If more refrigerant than the gas phase component ratio of the refrigerant separated in the gas-liquid separator 96 is sucked in from the injection pipe 95, the gas refrigerant in the gas-liquid separator 96 will be depleted, and the liquid refrigerant will flow into the injection pipe 95. ..

In order to maximize the capacity of the scroll compressor 91, it is desirable that the gas refrigerant separated in the gas-liquid separator 96 is sucked into the scroll compressor 91 through the injection pipe 95 without exhaustion. If it goes out of the equilibrium state, the liquid refrigerant flows from the injection pipe 95 into the scroll compressor 91. Therefore, it is necessary to configure the scroll compressor 91 so as to maintain high reliability even when the liquid refrigerant flows in from the injection pipe 95.

FIG. 7 is a sectional view taken along the line AA of FIG. 8 is a sectional view taken along the line BB of FIG.

At the intermediate pressure flowing from the injection pipe 95, as shown in FIGS. 1, 2, 7, and 8, the refrigerant flows into the intermediate pressure chamber 41 and opens the check valve 42 provided in the injection port 43. It is injected into the compression chamber 15 after being closed. The injected refrigerant is discharged from the discharge port 18 into the closed container 1 together with the refrigerant sucked from the suction port 17.

The injection port 43 for injecting the intermediate pressure refrigerant is provided through the end plate of the fixed scroll 12. The injection port 43 sequentially opens to the outer compression chamber 15a and the inner compression chamber 15b. The injection port 43 is provided at a position that opens to each compression chamber during the compression process after closing in each of the outer compression chamber 15a and the inner compression chamber 15b.

As shown in FIGS. 1 and 2, the scroll compressor 91 is provided with an intermediate pressure chamber 41 that is fed from the injection pipe 95 and guides the intermediate pressure working fluid before being injected into the compression chamber 15.

The intermediate pressure chamber 41 is formed of the fixed scroll 12 that is a compression chamber partition member, an intermediate pressure plate 44, and an intermediate pressure cover 45 (see FIG. 2). The intermediate pressure chamber 41 and the compression chamber 15 face each other with the fixed scroll 12 in between.

The intermediate pressure chamber 41 is located at a position lower than the intermediate pressure chamber inlet 41a into which the intermediate pressure working fluid flows, the injection port inlet 43a of the injection port 43 that injects the intermediate pressure working fluid into the compression chamber 15, and the intermediate pressure chamber inlet 41a. It has the formed liquid storage part 41b.

The liquid reservoir 41b is formed on the upper surface of the end plate of the fixed scroll 12.

The intermediate pressure plate 44 is provided with a check valve 42 that prevents the reverse flow of the refrigerant from the compression chamber 15 to the intermediate pressure chamber 41. When the internal pressure of the compression chamber 15 is higher than the intermediate pressure of the injection port 43 in the section where the injection port 43 is open to the compression chamber 15, the refrigerant flows backward from the compression chamber 15 toward the intermediate pressure chamber 41. Thus, by providing the check valve 42, the reverse flow of the refrigerant can be prevented.

In the scroll compressor 91 according to the present embodiment, the check valve 42 is configured by a reed valve 42a that lifts to the compression chamber 15 side and connects the compression chamber 15 and the intermediate pressure chamber 41. Therefore, the intermediate pressure chamber 41 can be communicated with the compression chamber 15 only when the internal pressure of the compression chamber 15 is lower than the pressure of the intermediate pressure chamber 41.

By using the reed valve 42a, there are few sliding parts in the movable part, the sealability can be maintained for a long time, and the flow passage area can be easily expanded as necessary.

When the check valve 42 is not provided and when the check valve 42 is provided in the injection pipe 95, the refrigerant in the compression chamber 15 flows back to the injection pipe 95, consuming useless compression power. In the present embodiment, the check valve 42 is provided on the intermediate pressure plate 44 near the compression chamber 15 to suppress the backflow from the compression chamber 15.

The top surface of the end plate of the fixed scroll 12 is located lower than the intermediate pressure chamber inlet 41a. On the upper surface of the end plate of the fixed scroll 12, a liquid storage portion 41b in which the refrigerant of the liquid phase component is stored is provided.

The injection port inlet 43a is provided at a position higher than the height of the intermediate pressure chamber inlet 41a. Therefore, of the intermediate-pressure working fluid, the refrigerant of the gas phase component is guided to the injection port 43, and the refrigerant of the liquid phase component accumulated in the liquid reservoir 41b is vaporized on the surface of the fixed scroll 12 in the high temperature state. It is difficult for the refrigerant of the liquid phase component to flow into the compression chamber 15.

Further, the intermediate pressure chamber 41 and the discharge chamber 31 are provided at positions adjacent to each other via the intermediate pressure plate 44. As a result, vaporization when the working fluid of the liquid phase component flows into the intermediate pressure chamber 41 is promoted, and the temperature rise of the high pressure refrigerant in the discharge chamber 31 can be suppressed. Therefore, the operation can be performed up to that high discharge pressure condition.

The intermediate-pressure refrigerant guided to the injection port 43 pushes the reed valve 42a open due to the pressure difference between the injection port 43 and the compression chamber 15, and joins the low-pressure refrigerant sucked from the suction port 17 in the compression chamber 15.

The intermediate-pressure refrigerant remaining in the injection port 43 between the check valve 42 and the compression chamber 15 repeats re-expansion and re-compression, which causes a reduction in the efficiency of the scroll compressor 91. Therefore, the thickness of the valve stop 42b that regulates the maximum displacement amount of the reed valve 42a is changed according to the lift regulation portion of the reed valve 42a, so that the internal volume of the injection port 43 downstream of the reed valve 42a is made small.

The reed valve 42a and the valve stop 42b are fixed to the intermediate pressure plate 44 by bolts 48 that are fixing members. The fixing hole of the bolt 48 provided in the valve stop 42b is opened only on the insertion side of the bolt 48 without penetrating the valve stop 42b. Therefore, as a result, the fixing member 48 is configured to open only to the intermediate pressure chamber 41. As a result, the working fluid can be prevented from leaking between the intermediate pressure chamber 41 and the compression chamber 15 through the gap of the fixing member 48, and the injection rate can be improved.

The volume of the intermediate pressure chamber 41 is set to be equal to or larger than the suction volume of the compression chamber 15 so that the injection amount into the compression chamber 15 can be sufficiently supplied. Here, the suction volume is the volume of the compression chamber 15 at the time when the working fluid introduced from the suction port 17 is closed in the compression chamber 15, that is, at the time of completion of the suction process, and is the outer compression chamber 15a and the inner compression chamber 15b. And is the total volume.

In the scroll compressor 91 according to the present embodiment, the intermediate pressure chamber 41 is provided so as to spread on the plane of the end plate of the fixed scroll 12 to increase the volume.

However, when a part of the oil 6 enclosed in the scroll compressor 91 exits from the scroll compressor 91 together with the discharged refrigerant and returns from the gas-liquid separator 96 to the intermediate pressure chamber 41 through the injection pipe 95, If the amount of oil 6 remaining in the liquid reservoir 41b is too large, a problem may occur in which the amount of oil 6 in the oil reservoir 20 is insufficient. Therefore, it is not appropriate that the volume of the intermediate pressure chamber 41 is too large. From this, it is preferable that the volume of the intermediate pressure chamber 41 is equal to or larger than the suction volume of the compression chamber 15 and equal to or smaller than 1/2 of the oil volume of the oil 6 to be enclosed.

As shown in FIG. 4, the injection port 43 is provided in the first compression chamber (outer compression chamber 15a) and the second compression chamber (inner compression chamber 15b) at positions that are sequentially opened. Further, as shown in (II) and (III) of FIG. 4, the injection port 43 is located at a position where it is opened to the outer compression chamber 15a in the compression stroke after the suction refrigerant is closed, or (in FIG. As shown in I), the end plate of the fixed scroll 12 is provided through the end plate at a position where it is opened to the inner compression chamber 15b in the compression stroke after closing the suction refrigerant.

In the present embodiment, the oil supply path is used as the communication path between the compression chamber and the back pressure chamber, but the same effect can be obtained by providing an independent path separately from the oil supply path. Further, the back pressure chamber is not limited to the back side of the orbiting scroll, but may be provided on the back side of the fixed scroll so that the fixed scroll is pressed against the orbiting scroll. Further, although the present embodiment has been described by using the scroll compressor having the injection pipe, the scroll compressor without the injection pipe may be used.

The scroll compressor according to the present disclosure is useful for a refrigerating device such as an air conditioner and air conditioner and a refrigerator, or a heat pump type hot water supply device.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Compression mechanism 3 Motor part 4 Shaft 4a Eccentric shaft part 6 Oil 11 Main bearing member 12 Fixed scroll 12a Recessed part 13 Orbiting scroll 13a Passage

13c Wrap tip

13e Rear surface 14 Rotation restraint mechanism 15 Compression chamber 15a

Outside compression chamber

15b, 15b -1,15b-2 Inside compression chamber 16 Suction pipe 17 Suction port 18 Discharge port 19 Discharge reed valve 20

Oil reservoir

21, 21a, 21b Discharge bypass port 22 Discharge pipe 25 Pump 26 Oil supply hole 29 Back pressure chamber 30 High pressure region 31 Discharge chamber 41 Intermediate pressure chamber 41a Intermediate pressure chamber inlet 41b Liquid reservoir 42 Check valve 42a Reed valve 42b Valve stop 43 Injection port 43a Injection port inlet 44 Intermediate pressure plate (intermediate pressure chamber partition member)
45 Intermediate pressure cover (intermediate pressure chamber partition member)
48 bolts (fixing member)
55 Oil supply path 55-1 Connection path 55-1a Other open end (high pressure area side)
55-1b One open end (back pressure chamber side)
55-2 Supply path 55-2a Opening end of other side (back pressure chamber side)
55-2b One open end (compression chamber side)
66 Bearing part 78 Seal member 91 Scroll compressor 92 Condenser 93

Evaporator

94, 94a, 94b Pressure reducer 95 Injection pipe 96 Gas-liquid separator

Claims

A fixed scroll having a first end plate and a first spiral wrap;
An orbiting scroll having a second end plate and a second spiral wrap;
A compression chamber configured by meshing the fixed scroll and the orbiting scroll,
A back pressure chamber for holding a back pressure for pressing the orbiting scroll against the fixed scroll,
The compression chamber has an outer compression chamber located outside the second spiral wrap of the orbiting scroll and an inner compression chamber located inside the second spiral wrap of the orbiting scroll. ,
The back pressure chamber communicates only with the outer compression chamber or the inner compression chamber during compression,
Each of the outer compression chamber and the inner compression chamber has a suction confined volume when the confinement of the working fluid is completed,
During compression, one of the outer compression chamber and the inner compression chamber communicates with the back pressure chamber,
When the communication between the one compression chamber and the back pressure chamber ends, the ratio of the suction closed volume of the one compression chamber to the volume of the one compression chamber is defined as the back pressure chamber closed volume ratio. ,
When the internal pressure of each of the outer compression chamber and the inner compression chamber rises to the discharge pressure or more and the ratio of the suction closed volume to the volume of the working fluid that can be discharged to the discharge path is a dischargeable volume ratio,
A scroll compressor in which the volume ratio when the back pressure chamber is closed is smaller than the dischargeable volume ratio of the one compression chamber.
The scroll compression according to claim 1, wherein the volume ratio when the back pressure chamber is closed is larger than the dischargeable volume ratio of the other compression chamber that is not in communication with the back pressure chamber, of the outer compression chamber and the inner compression chamber. Machine.
The scroll compression according to claim 1 or 2, wherein the suction closed volume of the outer compression chamber is larger than the suction closed volume of the inner compression chamber, and the one compression chamber is the inner compression chamber. Machine.
A discharge chamber from which the working fluid that has reached the discharge pressure is discharged,
A discharge port provided at the center of the fixed scroll,
A discharge bypass port that is provided in the other compression chamber that does not communicate with the back pressure chamber, and that communicates the other compression chamber and the discharge chamber prior to the discharge port,
By the discharge bypass port, the dischargeable volume ratio of the other compression chamber that does not communicate with the back pressure chamber is smaller than the dischargeable volume ratio of the one compression chamber that communicates with the back pressure chamber. The scroll compressor according to any one of claims 1 to 3, which is configured.
The back pressure chamber when the back pressure chamber and the one compression chamber end communication with each other,
The scroll compressor according to any one of claims 1 to 4, which is a closed space partitioned from another space having a pressure difference from the back pressure chamber.