WO2012042825A1

WO2012042825A1 - Rotary compressor

Info

Publication number: WO2012042825A1
Application number: PCT/JP2011/005395
Authority: WO
Inventors: 啓晶中井; 信吾大八木; 裕文吉田; 健苅野; 大輔船越; 竜一大野; 飯田　登
Original assignee: パナソニック株式会社
Priority date: 2010-09-27
Filing date: 2011-09-26
Publication date: 2012-04-05
Also published as: US20130189080A1; CN103154521A; JPWO2012042825A1

Abstract

As a result of using a refrigerant comprising at least a hydrofluoroolefin having carbon double bonds, a low ozone layer depletion factor and a low global warming potential, and providing a first compression chamber feed oil path which feeds refrigerating oil to a compression chamber (15) in which the refrigerant has been sealed, it is possible to limit the effect on the global environment and also to limit increases in the temperature of the refrigerant, which is the source of re-expansion and heating and also feeding of refrigerating oil at a high temperature, in other words it is possible to limit decomposition of the refrigerant.

Description

Rotary compressor

The present invention uses a refrigerant that does not contain chlorine atoms, has a low global warming potential, and contains at least a hydrofluoroolefin having a carbon double bond, such as a room air conditioner, a car air conditioner, a refrigerator, and other air conditioners. The present invention relates to a rotary compressor incorporated in a refrigeration cycle apparatus.

The refrigerant used in the refrigeration cycle apparatus has shifted to an HFC (hydrofluorocarbon) system (hereinafter referred to as “HFC-based refrigerant”) having a zero ozone depletion coefficient. However, this HFC-based refrigerant has a very high global warming potential. Therefore, development of a compressor using a refrigerant having a low ozone depletion coefficient and a global warming coefficient has been performed. However, a refrigerant with a low global warming potential is generally low in stability. For this reason, when used in a refrigeration cycle apparatus such as a room air conditioner, car air conditioner, refrigerator, or other air conditioner for a long period of time, it is necessary to ensure the stability and reliability of the refrigerant.

When using refrigerants mainly composed of hydrofluoroolefins that do not contain chlorine atoms, have a low global warming potential, and have carbon double bonds, there are the following problems. Since such a refrigerant has a characteristic of being easily decomposed at a high temperature, when it becomes a high temperature due to overcompression or re-expansion, it decomposes accordingly. Therefore, such a refrigerant has low stability. In particular, when used for a long time in room air conditioners, car air conditioners, refrigerators, other air conditioners, etc., decomposition of the refrigerant due to high temperatures takes place over a long period of time, so a measure against an increase in the temperature of the refrigerant is required.

In the refrigeration cycle, the refrigerant evaporated in the evaporator is sucked into the compressor and compressed to a specified pressure by the compressor. At that time, the state of the refrigerant largely changes from low pressure to high pressure and from low temperature to high temperature. Therefore, it is necessary to configure the compressor so as to ensure the stability and reliability of the refrigerant.

For example, Patent Document 1 discloses a compressor that uses a refrigerant having a low global warming potential, and supplies the refrigerant directly to the suction port in order to start compression of the refrigerant sucked into the compressor from as low a temperature as possible. A compressor having a direct suction path for the same is disclosed. With such a configuration, an increase in the temperature of the refrigerant before starting compression is suppressed as compared with a case where the refrigerant is temporarily stored in a storage space such as a crank chamber and then supplied to the compression chamber. The temperature of the refrigerant after being compressed to a specified pressure by the compressor is lower than the case where the refrigerant is not directly supplied to the suction port because the temperature rise is suppressed before the compression is started. As a result, the decomposition of the refrigerant is suppressed, and the failure of the compressor or the decrease in the service life due to the decomposition product (for example, sludge) of the refrigerant is suppressed. That is, the reliability and durability of the compressor are improved.

JP 2009-228473 A

However, even if the temperature rise of the refrigerant before the start of compression is suppressed, the temperature of the refrigerant after being compressed to a specified pressure by the compressor becomes higher than necessary, and as a result, the refrigerant may be decomposed. One of the causes is “re-expansion heating”. “Re-expansion heating” means that high-pressure refrigerant in the middle of compression leaks into a low-pressure space and re-expands in the low-pressure space to a high temperature, and as a result, heats the low-pressure refrigerant existing in the low-pressure space. To tell. By such re-expansion heating, the temperature of the refrigerant after being compressed to a specified pressure becomes higher than necessary. In addition, when re-expansion heating occurs, a part of the compression power (energy) spent to obtain the high-temperature / high-pressure refrigerant is used for heating the low-temperature / low-pressure refrigerant. descend.

As a method of suppressing such re-expansion heating caused by refrigerant leakage during compression, compression after confining the refrigerant by supplying refrigerating machine oil (oil) to the refrigerant before the start of compression (suction process) It is conceivable to improve the sealing performance of the chamber. However, there is a problem that the refrigerant before the start of compression (suction process) is heated by oil having a temperature higher than that of the refrigerant.

Therefore, in order to solve the above-mentioned problem, the present invention is a rotary compressor that uses a refrigerant having a low global warming potential, and uses refrigerating machine oil to improve the sealing performance of the compression chamber to re-expand. An object of the present invention is to provide a highly efficient rotary compressor excellent in reliability and durability, capable of suppressing heating and suppressing the heating of the refrigerant by the refrigerating machine oil.

In order to achieve the above object, the present invention is configured as follows.

In order to solve the conventional problem, according to one aspect of the present invention, a single refrigerant of hydrofluoroolefin having a carbon double bond or a mixed refrigerant containing the hydrofluoroolefin is used, and the refrigerant is compressed. There is provided a rotary compressor having a compression chamber and a first compression chamber oil supply passage for supplying refrigeration oil to the compression chamber after the refrigerant is confined.

By supplying refrigeration oil to the compression chamber after confining the refrigerant, the sealing performance of the compression chamber is improved, and re-expansion heating caused by leakage of the refrigerant in the middle of compression is suppressed. Heating is suppressed as compared with the case of supplying refrigeration oil in the suction process. As a result, the temperature of the refrigerant after being compressed to a specified pressure is reduced as compared with the case where the refrigerating machine oil is supplied in the suction process, thereby suppressing the decomposition of the refrigerant.

The reason why the temperature of the refrigerant after being compressed to the specified pressure is lower when the refrigerating machine oil is supplied to the compression chamber after confining the refrigerant than when the refrigerating machine oil is supplied in the suction process is as follows. It is.

The refrigerant that is being sucked into the compression chamber (during the intake stroke) has the lowest temperature. When high-temperature refrigeration oil is supplied to such a refrigerant, the refrigerant is strongly heated because the temperature difference between the refrigerant and the refrigeration oil is large (as a result, the decomposition of the refrigerant greatly proceeds). On the other hand, the refrigerant in the middle of compression has a small temperature difference from the supplied refrigerating machine oil because the temperature of the refrigerant itself increases with compression. Further, in the case of the refrigerant compressed to near the discharge pressure, the temperature of the refrigerant is higher than the temperature of the supplied refrigeration oil. Therefore, heating the refrigerant by the refrigerating machine oil can be suppressed by supplying the refrigerating machine oil to the compression chamber after confining the refrigerant (compression process). Thus, by supplying the refrigerating machine oil in the compression process while avoiding the refrigerating machine oil supply in the intake stroke, the refrigerating machine oil improves the sealing performance of the compression chamber after confining the refrigerant while suppressing the heating of the refrigerant. Can be made. It is desirable that the refrigerating machine oil is supplied at a timing where the temperature difference from the refrigerant is as small as possible.

According to the present invention, in the rotary compressor, it is possible to suppress an increase in the temperature of the refrigerant that causes the decomposition of the refrigerant while using the refrigerant having a low ozone layer depletion coefficient and a global warming coefficient. As a result, it is possible to provide a highly efficient rotary compressor that is excellent in reliability and durability while taking the global environment into consideration.

These aspects and features of the present invention will become apparent from the following description taken in conjunction with the preferred embodiments with reference to the accompanying drawings. In this drawing,
Sectional drawing of the scroll compressor which concerns on Embodiment 1 of this invention Partial expanded sectional view of the compression mechanism of the scroll compressor of Embodiment 1 The figure which shows the several state of the turning scroll of the scroll compressor of Embodiment 1 Partial expanded sectional view of the compression mechanism of the scroll compressor which concerns on Embodiment 2 of this invention. The figure which shows the several state of the turning scroll of the scroll compressor which concerns on Embodiment 2. FIG. Sectional drawing of the rotary compressor which concerns on Embodiment 3 of this invention. Enlarged sectional view of the compression mechanism of the rotary compressor of the third embodiment Assembly configuration diagram of compression mechanism of rotary compressor of embodiment 3 The figure which shows the several state of the compression mechanism of the rotary compressor of Embodiment 3.

A rotary compressor according to the present invention uses a single refrigerant of hydrofluoroolefin having a carbon double bond or a mixed refrigerant containing the hydrofluoroolefin, a compression chamber for compressing the refrigerant, and confining the refrigerant And a first compression chamber oil supply passage for supplying refrigeration oil to the compression chamber after the first compression chamber. By using a refrigerant with a low ozone layer depletion coefficient and a global warming coefficient, the influence on the global environment can be suppressed. In addition, in order to solve the problem that the single refrigerant (or mixed refrigerant) of hydrofluoroolefin having a carbon double bond is easily decomposed at a high temperature, refrigerating machine oil is supplied to the compression chamber after the refrigerant is confined. The As a result, the re-expansion heating caused by the leakage of the refrigerant in the middle of compression is suppressed by improving the sealing performance of the compression chamber, and the temperature rise of the refrigerant caused by the supply of the refrigerating machine oil is caused by the suction process (refrigerant Before the refrigerating machine oil is supplied). As a result, the temperature of the refrigerant after being compressed to the specified pressure is lower than that in the case where the refrigerating machine oil is supplied in the suction process, and the decomposition of the refrigerant is suppressed. In addition, it is possible to provide a highly efficient rotary compressor that is excellent in reliability and durability while considering the global environment.

The compressor may be configured to intermittently block the first compression chamber oil supply path. Refrigerating machine oil can be supplied to the compression chamber at an optimal timing and with an optimal amount capable of effectively realizing improvement in the sealing performance of the compression chamber and suppression of the temperature rise of the refrigerant caused by supply of the refrigerator oil. Thereby, the temperature rise of the refrigerant | coolant by supply of refrigerating machine oil and the re-expansion heating by the leak of a refrigerant | coolant can be suppressed more reliably.

When the compression chamber is formed between the fixed scroll and the orbiting scroll by meshing the fixed scroll and the orbiting scroll each having an end plate and a wrap which is a spiral wall formed on the end plate And providing at least one second compression chamber oil supply passage for supplying the refrigerator oil to the compression chamber from an oil storage section for storing the refrigerator oil, wherein at least one of the second compression chamber oil supply passages is the first compression chamber oil supply. It may be a route.

In general, in a rotary compressor that includes a plurality of compression chambers and compresses refrigerants in a plurality of compression chambers at the same time, when refrigerant in the middle of compression that has been compressed to a certain high pressure leaks into the compression chamber on the low-pressure side, the refrigerant is refrigerant. It is easy to leak into the compression chamber in the middle of the compression after one step rather than the compression chamber in the middle of sucking (so-called internal leakage occurs). In that case, the re-expansion of the leaked refrigerant not only heats the refrigerant in the leaked compression chamber, but also increases the pressure in the leaked compression chamber. Due to such internal leakage, the temperature of the refrigerant rises. As a countermeasure against this, by providing at least one second compression chamber oil supply path for supplying the refrigeration oil to the compression chamber, an internal leak that particularly contributes to an increase in the temperature of the refrigerant occurs using an optimal amount of the refrigeration oil. It becomes possible to improve the sealing performance of the compression chamber. Further, by using an optimal amount of refrigerating machine oil, it is possible to suppress heating of the refrigerant by an extra refrigerating machine oil that occurs when an excessive amount of refrigerating machine oil is supplied.

When the compression chamber includes a first compression chamber formed outside the orbiting scroll wrap and a second compression chamber formed inside the orbiting scroll wrap, the first compression chamber Of the second compression chamber, the supply amount of the refrigerating machine oil to the compression chamber having the longer leak length may be made larger than the supply amount to the other compression chamber. The amount of refrigeration oil supplied to improve the sealing performance corresponding to the length of the leak point in the compression chamber can be optimized, so extra refrigeration oil that occurs when an excessive amount of refrigeration oil is supplied. Heating of the refrigerant due to can also be suppressed.

When the compression chamber has a first compression chamber formed outside the wrap of the orbiting scroll and a second compression chamber formed inside the wrap of the orbiting scroll, the first compression chamber Of the second compression chambers, the amount of the refrigerating machine oil supplied to the compression chamber having the higher volume change rate may be increased compared to the amount of oil supplied to the other compression chamber. The optimum amount of refrigerating machine oil can improve the sealing performance of the compression chamber where refrigerant leakage is likely to occur because the pressure difference from the compression chamber on the low pressure side is large. The heating of the refrigerant by the extra refrigeration oil that occurs when an excessive amount of refrigeration oil is supplied can also be suppressed.

The first compression chamber oil supply path is provided on the back surface of the orbiting scroll and is introduced into the wrap of the orbiting scroll and communicated with the introduction path portion provided in the wrap of the orbiting scroll. You may comprise from the lap | oil top oil supply path part provided with an opening in a lap | lap top surface, and the recessed part provided in the end plate of the said fixed scroll, and communicating with the opening of the said lap oil supply path part intermittently. Thereby, it becomes possible to supply the refrigerating machine oil to the compression chamber after confining the refrigerant in a specific period, and to easily adjust the supply amount of the refrigerating machine oil. Further, it is possible to prevent the compressed refrigerant from flowing back into the first compression chamber oil supply path, and it is possible to realize a highly reliable scroll compressor.

The refrigerant includes at least one of tetrafluoropropene or trifluoropropene, which is a kind of hydrofluoroolefin, and may have a global warming potential of 5 or more and 750 or less, preferably 5 or more and 350 or less. . According to such a refrigerant, it is possible to effectively provide a rotary compressor having a low environmental load and high reliability and high efficiency.

The refrigerant is mainly composed of tetrafluoropropene or trifluoropropene, which is a kind of hydrofluoroolefin, and difluoromethane and pentafluoroethane preferably have a global warming potential of 5 or more and 750 or less, preferably 5 or more and 350 or less. What was mixed so that it may become may be sufficient. According to such a refrigerant, the environmental load is small, and the temperature can be lowered by suppressing the flow rate, so that a highly reliable and highly efficient rotary compressor can be effectively provided.

As refrigerating machine oils, (1) polyoxyalkylene glycols, (2) polyvinyl ethers, (3) poly (oxy) alkylene glycols or their monoether and polyvinyl ether copolymers, (4) polyol esters and polycarbonates A synthetic oil containing the oxygen-containing compound of (5), a synthetic oil mainly composed of alkylbenzenes, or (6) a synthetic oil mainly composed of α-olefins may be used. Such a refrigerating machine oil can effectively provide a highly reliable and highly efficient rotary compressor.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

In the compressors according to the three embodiments of the present invention described below, a single refrigerant of hydrofluoroolefin having a carbon double bond or a mixed refrigerant containing the hydrofluoroolefin is used.

(Embodiment 1)
1 is a longitudinal sectional view of a scroll compressor according to Embodiment 1 of the present invention, FIG. 2 is a partially enlarged sectional view of the compression mechanism shown in FIG. 1, and FIG. 3 shows a plurality of states of the orbiting scroll of the compression mechanism. FIG. Hereinafter, operation | movement and an effect | action are demonstrated about a scroll compressor.

As shown in FIG. 1, the scroll compressor according to the first embodiment has a sealed container 1. The scroll compressor also has a compression mechanism 2, a motor unit 3, and an oil storage unit 20 inside the sealed container 1. The compression mechanism 2 includes a main bearing member 11 fixed to the sealed container 1 by welding or shrink fitting, a shaft 4 supported by the main bearing member 11, and a fixing fixed on the main bearing member 11 by bolts or the like. The scroll 12 is configured between a main scroll member 11 and a fixed scroll 12, and a revolving scroll 13 that meshes with the fixed scroll 12.

The fixed scroll 12 includes an end plate 12a and a wrap 12b that is a spiral wall formed on the end plate 12a. The orbiting scroll 13 includes an end plate 13a and a wrap 13b that is a spiral wall formed on the end plate 13a. Is provided. Between the orbiting scroll 13 and the main bearing member 11, there is provided an Oldham ring or the like that prevents the orbiting scroll 13 from rotating and guides the orbiting scroll 13 driven by the shaft 4 to move in a circular orbit. A restraining mechanism 14 is provided. The eccentric shaft portion 4 a located at the upper end of the shaft 4 rotates the orbiting scroll 13 eccentrically, whereby the orbiting motion of the orbiting scroll 13 is realized.

With such a configuration, 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 center. Refrigerant (gas) is sucked into the compression chamber 15 through the suction pipe 16 communicating with the outside of the hermetic container 1 and the suction port 17 in the outer peripheral portion of the fixed scroll 12 (suction process). After the compression chamber 15 is closed by the revolving motion of the orbiting scroll 13 (after the refrigerant is confined in the compression chamber 15), the refrigerant is compressed (compression step). The refrigerant that has reached a specified pressure by compression pushes open the reed valve 19 provided in the discharge hole 18 in the center of the fixed scroll 12 and moves from the compression chamber 15 into the sealed container 1 through the discharge hole 18.

Also, a pump 25 is provided at the other end of the shaft 4. The pump 25 is arranged so that the suction port exists in the oil storage part 20 provided at the bottom of the sealed container 1. Since the pump 25 is driven in synchronization with the compression mechanism 2, the pump 25 can reliably suck up the refrigeration oil (oil) 6 stored in the oil storage unit 20 regardless of the pressure condition or the operation speed. And it can supply to the compression mechanism 2 stably. The oil 6 sucked up by the pump 25 is supplied to the compression mechanism 2 through an oil supply hole 26 penetrating the shaft 4. Note that foreign matter in the oil 6 is removed by an oil filter or the like before or after being sucked up by the pump 25, so that foreign matter can be prevented from entering the compression mechanism 2. As a result, the reliability of the compressor is further improved. Improvements can be made.

Since the pressure of the oil 6 introduced into the compression mechanism 2 is substantially the same as the discharge pressure of the scroll compressor, it becomes a back pressure source for the orbiting scroll 13. That is, the oil 6 functions to press the back surface of the orbiting scroll 13 (the surface facing the main bearing member 11) and press the orbiting scroll 13 against the fixed scroll 12. Thereby, the orbiting scroll 13 is maintained in a state in which it is in contact with the fixed scroll 12 without leaving the fixed scroll 12 and without being in partial contact with the fixed scroll 12. As a result, the compression mechanism 2 can stably exhibit a predetermined compression capacity. Further, a part of the oil 6 enters a fitting portion between the eccentric shaft portion 4a and the orbiting scroll 13 and a bearing portion 66 provided between the shaft 4 and the main bearing member 11 by supply pressure or its own weight, and Lubricate. The oil 6 after being lubricated falls and returns to the oil storage section 20 as indicated by arrows in FIG.

Further, by disposing the seal member 78 between the back surface of the orbiting scroll 13 and the main bearing member 11, the high pressure region 30 is defined inside the seal member 78, and the back pressure chamber 29 is disposed outside the seal member 78. Defined. Since the pressure in the high pressure region 30 and the pressure in the back pressure chamber 29 can be completely separated, the pressure on the back surface of the orbiting scroll 13 can be stably controlled.

A recess 12d is formed in a portion 12c of the end plate 12a between the wraps 12b of the fixed scroll 12. In addition, the orbiting scroll 13 is formed with an in-lap oil supply passage 55. The in-lap oil supply passage 55 communicates with the back pressure chamber 29 through one opening 55a. The back pressure chamber 29 communicates with the oil storage section 20 via an introduction path 54 provided on the back side of the orbiting scroll 13 and an oil supply hole 26 provided in the shaft 4. On the other hand, the other opening 55 b of the in-wrap oil supply passage 55 is formed on the top surface of the wrap 13 a that is in sliding contact with the end plate 12 a of the fixed scroll 12. As shown by a broken line in FIG. 3, the opening 55 b of the in-lap oil supply passage 55 moves relative to the fixed scroll 12 so as to draw a circular turning locus by a turning motion of the turning scroll 13.

FIG. 3 shows a plurality of states of the orbiting scroll 13 meshed with the fixed scroll 12, and specifically shows the states of the orbiting scroll 13 whose phases are different by 90 degrees. As shown in FIG. 3, as the compression chamber 15 formed by the fixed scroll 12 and the orbiting scroll 13, a first compression chamber 15a formed outside the wrap 13a of the orbiting scroll 13 and formed inside the wrap 13a. And a second compression chamber 15b. Each of the first compression chamber 15a and the second compression chamber 15b moves toward the center while reducing the volume by the orbiting motion of the orbiting scroll 13. When the refrigerant in the compression chamber 15 reaches the discharge pressure and the compression chamber 15 and the discharge hole 18 communicate with each other, the refrigerant in the compression chamber 15 moves into the discharge chamber 31 by opening the reed valve 19.

As shown in FIG. 3, the opening 55 b of the in-lap oil supply passage 55 and the recess 12 d formed in the portion 12 c of the end plate 12 a of the fixed scroll 12 communicate intermittently. Thereby, the in-lap oil supply passage 55 and the second compression chamber 15b are intermittently communicated with each other through the recess 12d.

Hereinafter, description will be made with attention paid to the second compression chamber 15b. As shown in FIG. 3A, the second compression chamber 15b formed on the outermost side of the orbiting scroll 13 and the suction port 17 communicate with each other, and introduction of the refrigerant into the second compression chamber 15b is started. (Start of inhalation process). And as shown in FIG.3 (c), the 2nd compression chamber 15b is closed by the turning motion of the turning scroll 13, and a refrigerant | coolant is confined in the 2nd compression chamber 15b (start of a compression process). Thereafter, as shown in FIG. 3 (d), the opening 55b of the in-lap oil supply passage 55 communicates with the second compression chamber 15b through the recess 12d by the orbiting motion of the orbiting scroll 13, and the in-lap oil supply passage 55 The oil 6 is supplied to the second compression chamber 15b after confining the refrigerant from the back pressure chamber 29 via On the other hand, as shown in FIGS. 3A to 3C, when the opening 55b and the recess 12d are not in communication, almost no oil is supplied from the back pressure chamber 29 to the second compression chamber 15b. In this way, the second compression chamber 15b is connected to the second compression chamber 15b through the in-lap oil supply passage 55 by intermittently communicating the opening 55b of the in-lap oil supply passage 55 and the second compression chamber 15b through the recess 12d of the fixed scroll 12. Oil 6 is intermittently supplied to the chamber 15b. The reason for supplying the oil 6 to the second compression chamber 15b will be described later.

As described above, according to Embodiment 1, by using a single hydrofluoroolefin refrigerant or a mixed refrigerant containing the hydrofluoroolefin having a low ozone depletion coefficient and a low global warming coefficient, The influence on can be suppressed. Further, by supplying the oil 6 to the second compression chamber 15b after the refrigerant is confined (compression process), the temperature of the refrigerant after being compressed to a predetermined pressure is communicated with the suction process (that is, the suction port 17). Compared to the case of supplying the oil 6 in the state).

Compared with the case where the oil 6 is supplied to the second compression chamber 15b in the suction process, the temperature of the refrigerant after being compressed to the specified pressure is higher when the oil 6 is supplied to the second compression chamber 15b in the suction process. The reason why is low is as follows.

The temperature of the refrigerant that is being sucked into the second compression chamber 15b (during the suction stroke) has the lowest temperature. When the high-temperature oil 6 is supplied to such a refrigerant, the refrigerant is strongly heated because the temperature difference between the refrigerant and the oil 6 is large (as a result, the refrigerant is greatly decomposed). On the other hand, the refrigerant in the middle of compression has a small temperature difference from the supplied oil 6 because the temperature of the refrigerant itself increases with compression. Furthermore, in the case of the refrigerant compressed to near the discharge pressure, the temperature of the refrigerant is higher than the temperature of the supplied oil 6. Therefore, heating the refrigerant by the oil 6 can be suppressed by supplying the oil 6 to the second compression chamber 15b after the refrigerant is confined (compression process). Thus, by supplying the oil 6 in the compression process while avoiding the supply of the oil 6 in the suction stroke, the sealing performance of the second compression chamber 15b after confining the refrigerant is suppressed while suppressing the heating of the refrigerant. It can be improved by the oil 6. The oil 6 is desirably supplied at a timing at which the temperature difference from the refrigerant is as small as possible.

Further, the oil 6 improves the sealing performance of the second compression chamber 15b (between the end plate 12a of the fixed scroll 12 and the wrap 13b of the orbiting scroll 13 and between the wrap 12b and the end plate 13a). That is, the leakage of the refrigerant from the second compression chamber 15b can be suppressed.

As a result, the temperature rise of the refrigerant is suppressed and the decomposition of the refrigerant is suppressed. In addition, it is possible to provide a highly efficient rotary compressor that is excellent in reliability and durability while considering the global environment.

Further, when the orbiting scroll 13 is in a specific phase (that is, when the shaft 4 is at a specific rotation angle), the oil 6 on the rear surface of the orbiting scroll 13 is secondly passed through the oil supply passage 55 in the lap and the recess 12d. Can be supplied to the compression chamber 15b. That is, the oil 6 is supplied to the second compression chamber 15b at an optimal timing and in an optimal amount capable of effectively realizing the improvement in the sealing performance of the second compression chamber 15b and the suppression of the temperature rise of the refrigerant due to the supply of the oil 6. Can be supplied to. Thereby, the temperature rise of the refrigerant caused by the supply of the oil 6 and the re-expansion heating caused by the leakage of the refrigerant can be more reliably suppressed.

From here, the reason why the oil 6 is supplied to the second compression chamber 15b via the in-lap oil supply passage 55 will be described. First, the shape of the wrap provided in the fixed scroll 12 and the turning scroll 13 will be described. In the present embodiment, the spiral shape of the fixed scroll and the orbiting scroll wrap is defined by an involute curve. The involute curve is expressed by the following function in the Cartesian coordinate system, where θ is the expansion angle and a is the base circle radius.

The curve represented by Equation 1 is used as the reference curve. Of the two envelopes drawn by the reference curve when turning at the turning radius ε, the outer envelope is expressed by the following function.

Similarly, the inner envelope is expressed by the following function.

By defining the outer surface of one of the fixed scroll 12 and the orbiting scroll 13 as a function of the above-mentioned reference curve and defining it as a function of the above-mentioned outer envelope of the inner surface of the other lap combined therewith, the fixed scroll The plurality of minimum radial gaps on the inner surface side of the wrap 13b of the orbiting scroll 13 or the plurality of minimum radial gaps on the outer surface side of the wrap 13b of the orbiting scroll 13 formed simultaneously by meshing the laps of the lap and the orbiting scroll lap. Will be equal. In the present embodiment, the volume of the compression chamber 15 is increased by forming the asymmetric compression chamber 15 by forming the wrap 12b of the fixed scroll 12 and the wrap 13b of the orbiting scroll 13 so that the number of turns is different. I am trying.

Since the asymmetric compression chamber is formed, the volume change rate of the second compression chamber 15b formed on the inner surface side of the wrap 13b of the orbiting scroll 13 is the first compression chamber formed on the outer surface side of the wrap 13b. Larger than the volume change rate of 15a. In the second compression chamber 15b having a large volume change rate, the pressure of the refrigerant rapidly increases as compared with the first compression chamber 15a, so that the pressure difference with the compression chamber 15 on the low pressure side becomes large. Therefore, the refrigerant is liable to leak from the second compression chamber 15b to the low-pressure side compression chamber 15 between the wrap and the end plate, and it is necessary to improve the sealing performance.

Therefore, in the first embodiment, the in-lap oil supply passage 55 and the recess 12d are appropriately provided so that more oil 6 is supplied to the second compression chamber 15b having a large volume change rate. As a result, leakage of the refrigerant from the second compression chamber 15b to the low-pressure side compression chamber 15 is suppressed, re-expansion heating to the refrigerant in the low-pressure side compression chamber 15 is suppressed, and internal leakage is caused. An increase in pressure can be suppressed. As a result, the temperature rise of the refrigerant used in the scroll compressor according to the first embodiment, which is easily decomposed at a high temperature, is suppressed.

In addition, another compression chamber oil supply path (second compression chamber oil supply path excluding the first compression chamber oil supply path) for supplying the oil 6 to the first compression chamber 15a is provided, and the second compression chamber 15b is provided. A small amount of oil 6 compared to the amount of oil 6 supplied intermittently may be supplied to the first compression chamber 15a via another compression chamber oil supply path. As such another compression chamber oil supply path, for example, a compression chamber oil supply path 57 shown in FIG. 2 is provided. The compression chamber oil supply path 57 is formed in the orbiting scroll 13. Further, one opening of the compression chamber oil supply passage 57 is formed on the top surface of the wrap 13b. The other opening communicates with the oil storage section 20 through an introduction path 54 provided on the back surface of the orbiting scroll 13, an oil supply hole 26 provided in the shaft 4, and the like. Thus, a small amount of oil 6 can be supplied from the gap between the end plate 12 a of the fixed scroll 12 and the top surface of the wrap 13 b of the orbiting scroll 13.

Also in this case, re-expansion heating with respect to the refrigerant is suppressed and an increase in pressure due to internal leakage can be suppressed. Further, since the supply amount of the oil 6 to the second compression chamber 15b having a high volume change rate is larger than the supply amount to the first compression chamber 15a, the pressure difference with the compression chamber 15 on the low pressure side is large. In addition, it is possible to improve the sealing performance of the compression chamber, in which refrigerant leakage is likely to occur, with an optimal amount of oil. Thereby, the heating of the refrigerant | coolant by the extra refrigerating machine oil which arises by supplying an excessive amount of refrigerating machine oil can also be suppressed.

Further, with respect to the amount of oil 6 supplied to the second compression chamber 15b, a small amount of oil compared to the amount of oil supplied after confining the refrigerant (after the second compression chamber 15b is closed), It may be supplied before the refrigerant is confined (before the second compression chamber 15b starts to close) or during the confinement of the refrigerant (from the time when the second compression chamber 15b starts to close until it completely closes). That is, if most of the necessary amount of oil 6 is supplied after confining the refrigerant, the temperature rise of the refrigerant, that is, the decomposition of the refrigerant can be suppressed.

(Embodiment 2)
FIG. 4 is a partially enlarged cross-sectional view of the compression mechanism of the scroll compressor according to Embodiment 2 of the present invention. FIG. 5 is a diagram showing a plurality of states of the orbiting scroll. Components other than the compression chamber oil supply path 56 are the same as those in the first embodiment. 4 and 5, the same reference numerals are used for the same components as those in FIGS. 2 and 3. Moreover, only the description regarding the compression chamber oil supply path | route 56 is performed, and description of another component is abbreviate | omitted.

As shown in FIG. 4, in the scroll compressor of the second embodiment, the compression chamber oil supply path 56 is formed in the end plate 13 a of the orbiting scroll 13. Further, the compression chamber oil supply path 56 communicates the back pressure chamber 29 and the first compression chamber 15 a formed on the outer surface side of the wrap 13 b of the orbiting scroll 13. However, the compression chamber oil supply passage 56 communicates with the first compression chamber 15a and supplies the oil 6 to the first compression chamber 15a when the orbiting scroll 13 is in the state shown in FIG. In the states shown in (a), 5 (c), and 5 (d), the oil 6 is not supplied to the first compression chamber 15a because it is blocked by the end plate 12a of the fixed scroll 12. As for the scroll compressor in which the volume of the compression chamber is reduced as it moves from the outer periphery toward the center, the compression chamber on the outer side has a larger volume than the compression chamber located on the center side. Therefore, the leakage length (in other words, the required seal length), which is the length of the location where the refrigerant leaks from the high-pressure side compression chamber with a small volume to the low-pressure side compression chamber with a large volume, is the wrap 13b of the orbiting scroll 13. The first compression chamber 15a formed outside is longer than the second compression chamber 15b formed inside. Therefore, a larger amount of oil 6 than the amount of oil 6 supplied to the second compression chamber 15b is supplied to the first compression chamber 15a having a long leakage length via the compression chamber oil supply passage 56. Thus, the first compression chamber 15a having a long leakage length is sufficiently sealed. Thereby, the temperature rise of the refrigerant | coolant which is easy to decompose | disassemble at high temperature is suppressed.

According to the second embodiment, the pressure increase due to re-expansion heating of the refrigerant and internal leakage can be suppressed, and the amount of oil 6 supplied to the first compression chamber 15a having a long leak length is reduced to the second compression chamber 15b. Since the amount of oil 6 for improving the sealing performance can be optimized in accordance with the length of the leaking portion of the compression chamber, an excessive amount of refrigerating machine oil is supplied. The heating of the refrigerant by the extra refrigeration oil which occurs by this can also be suppressed.

(Embodiment 3)
FIG. 6 is a longitudinal sectional view of a rotary compressor according to Embodiment 3 of the present invention. FIG. 7 is an enlarged cross-sectional view of a compression mechanism of the rotary compressor. FIG. 8 is an assembly configuration diagram of the compression mechanism of the rotary compressor. And FIG. 9 is a figure which shows the several state of the compression mechanism of a rotary compressor. As shown in FIGS. 6 and 7, in the rotary compressor, the electric motor 102 and the compression mechanism 103 are housed in the hermetic container 101 in a state of being connected via a crankshaft 131. The compression mechanism 103 includes a cylinder 130, a suction chamber 149 and a compression chamber 139 formed by the end plate 134 of the upper bearing 134a and the end plate 135 of the lower bearing 135a that block both end faces of the cylinder 130, And a vane 133 that contacts the outer peripheral surface of the piston 132 and divides the cylinder 130 into a suction chamber 149 and a compression chamber 139. The piston 132 is fitted into the eccentric portion 131a of the crankshaft 131 supported by the side bearing 134a and the lower bearing 135a, and is eccentrically rotated by the crankshaft 131. The vane 133 is configured to reciprocate toward the piston 132 in response to the eccentric rotation of the piston 132 in order to maintain contact with the outer peripheral surface of the piston 132 that rotates eccentrically.

The crankshaft 131 is formed with an oil hole 141 along the central axis that draws oil from the oil storage section 20. Oil supply holes 142 and 143 communicating with the oil hole 141 are provided in the portion of the crankshaft 131 that faces the upper bearing 134a and the lower bearing 135a. An oil supply hole 144 that communicates with the oil hole 141 and an oil groove 145 that communicates with the oil supply hole 14 are formed in the portion of the eccentric portion 131 a of the crankshaft 131 that faces the piston 132.

On the other hand, the cylinder 130 is formed with a suction port 140 for sucking gas refrigerant into the suction chamber 149. When the sliding contact portion of the piston 132 that is in sliding contact with the inner peripheral surface of the cylinder 130 passes through the suction port 140 and is separated from the suction port 140, the suction chamber 149 gradually expands, whereby the refrigerant flows from the suction port 140 to the suction chamber. 149 is inhaled. A discharge port 138 for discharging the refrigerant from the compression chamber 139 is opened in the upper bearing 134a. The discharge port 138 is formed as a hole having a circular cross section passing through the upper bearing 134a. On the upper surface of the discharge port 138, there are provided a discharge valve 136 that opens when a pressure equal to or higher than a predetermined pressure is received, and a cup muffler 137 that covers the discharge valve 136.

As the sliding portion of the piston 132 slidably contacting the inner peripheral surface of the cylinder 130 approaches the discharge port 138, the compression chamber 139 is gradually reduced. When the refrigerant in the compression chamber 139 is compressed to a predetermined pressure or higher, the discharge valve 136 is opened. When the discharge valve 136 is opened, the refrigerant flows out from the discharge port 138 and is discharged into the sealed container 101 by the cup muffler-137.

On the other hand, the eccentric portion 131a of the crankshaft 131, the end plate 134 of the upper bearing 134a, the space 146 surrounded by the inner peripheral surface of the piston 132, the eccentric portion 131a of the crankshaft 131, the end plate 135 of the lower bearing 135a, and A space 147 surrounded by the inner peripheral surface of the piston 132 is formed. Oil leaks into the

spaces

146 and 147 from the oil holes 141 through the oil supply holes 142 and 143. The pressures in the

spaces

146 and 147 are almost always higher than the pressure in the compression chamber 139 and are almost the same as the discharge pressure.

Also, the height of the cylinder 130 is set to be slightly larger than the height of the piston 132 so that the piston 132 can slide inside the cylinder 130. Therefore, there is a gap between the end surface of the piston 132 and the end plate 134 of the upper bearing 134a and the end plate 135 of the lower bearing 135a. Oil in the

spaces

146 and 147 leaks into the compression chamber 139 through this gap.

In the rotary compressor configured as described above, as shown in FIG. 8, the end plate 135 of the lower hour bearing 135a is provided with a concave compression chamber oil supply passage 155. FIG. 9 shows the positional relationship between the piston 132 and the oil supply passage 155 when viewed from the central axis direction of the crankshaft 131. As shown in the lower left of FIG. 9, the crankshaft 131 crankshaft in which the inlet 155a of the compression chamber oil supply passage 155 and the inside of the piston 132 communicate with each other and the outlet 155b of the compression chamber oil supply passage 155 and the compression chamber 139 communicate with each other. The compression chamber 139 is refueled in the angular section. By providing the compression chamber oil supply passage 155 so that the angle positions of the inlet 155a and the outlet 155b with respect to the crankshaft center are different, it is possible to determine a crank angle section in which oil flows into the inlet 155a. Thereby, the freedom degree of the position of the exit 155b increases. As a result, the outlet 155b of the compression chamber oil supply path 155 can be provided in the vicinity of the location where the refrigerant leaks.

Further, as shown in the lower left of FIG. 9, by providing an outlet 155b of the compression chamber 155 near the contact point between the piston 132 and the cylinder 130 in the compression chamber 139, a minimum amount of oil can be used between the piston 132 and the cylinder 130. It is possible to suppress leakage of the refrigerant. Thereby, the temperature rise of the refrigerant | coolant which is easy to decompose | disassemble at high temperature is suppressed.

According to the third embodiment, the influence on the global environment can be suppressed by using a refrigerant having a low ozone layer depletion coefficient and a global warming coefficient. In addition, by supplying oil to the compression chamber 139 after confining the refrigerant, re-expansion heating of the refrigerant is suppressed, and the refrigerant is heated by the refrigerating machine oil in the suction process (before the refrigerant is confined in the compression chamber). Is suppressed as compared with the case of supplying refrigeration oil. As a result, the decomposition of the refrigerant is suppressed.

The rotary compressor according to the first to third embodiments has been described above. In the rotary compressors of Embodiments 1 to 3, a single refrigerant of hydrofluoroolefin having a carbon double bond or a mixed refrigerant containing the hydrofluoroolefin is used. As this mixed refrigerant, a refrigerant obtained by mixing hydrofluoroolefin and hydrofluorocarbon having no carbon double bond may be used.

Further, a mixed refrigerant of tetrafluoropropene (HFO1234yf or HFO1234ze) or trifluoropropene (HFO1243zf), which is a kind of hydrofluoroolefin, and difluoromethane (HFC32), which is a kind of hydrofluorocarbon, may be used.

Furthermore, a mixed refrigerant of tetrafluoropropene (HFO1234yf or HFO1234ze) or trifluoropropene (HFO1243zf), which is a kind of hydrofluoroolefin, and pentafluoroethane (HFC125), which is a kind of hydrofluorocarbon, may be used.

Furthermore, tetrafluoropropene (HFO1234yf or HFO1234ze) or trifluoropropene (HFO1243zf), which is a kind of hydrofluoroolefin, and pentafluoroethane (HFC125) and difluoromethane (HFC32), which are kinds of hydrofluorocarbon, were mixed. A mixed refrigerant composed of three components may be used.

The above mixed refrigerant is preferably a mixture of two or three components mixed so that the global warming potential is 5 or more and 750 or less, preferably 5 or more and 350 or less.

The refrigerating machine oil used in the rotary compressor according to the present invention includes (1) polyoxyalkylene glycols, (2) polyvinyl ethers, (3) poly (oxy) alkylene glycols or monoethers thereof and polyvinyl ethers. (4) Synthetic oils containing oxygenated compounds of polyol esters and polycarbonates, (5) Synthetic oils based on alkylbenzenes, or (6) Synthetic oils based on α-olefins Is preferred.

Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.

The disclosures of the specification, drawings, and claims of Japanese Patent Application No. 2010-214877 filed on Sep. 27, 2010 are incorporated herein by reference in their entirety. .

As described above, according to the present invention, even when a single refrigerant of hydrofluoroolefin having a carbon double bond or a mixed refrigerant containing the hydrofluoroolefin is used, the rotary compressor has high reliability, High durability and high efficiency can be realized. Therefore, this invention is applicable also to uses, such as an air conditioner, a heat pump type water heater, a refrigerator-freezer, a dehumidifier, provided with a rotary compressor.

DESCRIPTION OF SYMBOLS 12 Fixed scroll 12a End plate 12b Wrap 12d Recess 13 Orbiting scroll 13a End plate 13b Wrap 14 Rotation restraint mechanism 15 Compression chamber 15a First compression chamber 15b Second compression chamber 17 Suction port 18 Discharge hole 19 Reed valve 20 Oil storage unit 29 Back pressure Chamber 30 High-pressure region 55 Oil supply path in lap 56 Compression chamber oil supply path 130 Cylinder 131 Crankshaft 133 Vane 134a Upper bearing 135a Lower bearing 139 Compression chamber 141 Oil hole 155 Compression chamber oil supply path

Claims

A single refrigerant of a hydrofluoroolefin having a carbon double bond or a mixed refrigerant containing the hydrofluoroolefin is used,
A compression chamber for compressing the refrigerant;
A rotary compressor having a first compression chamber oil supply path for supplying refrigeration oil to the compression chamber after confining the refrigerant.
The rotary compressor according to claim 1, wherein the rotary compressor is configured to intermittently block the first compression chamber oil supply path.
The compression chamber is formed between the fixed scroll and the orbiting scroll by meshing the fixed scroll and the orbiting scroll each having a mirror plate and a wrap that is a spiral wall formed on the mirror plate,
An oil storage section for storing refrigerating machine oil;
Having at least one second compression chamber oil supply path for supplying refrigeration oil from the oil storage section to the compression chamber;
The rotary compressor according to claim 1 or 2, wherein at least one of the second compression chamber oil supply paths is the first compression chamber oil supply path.
As the compression chamber, it has a first compression chamber formed outside the wrap of the orbiting scroll, and a second compression chamber formed inside the wrap of the orbiting scroll,
The supply amount of the refrigerating machine oil to the compression chamber having the longer leakage length of the first compression chamber and the second compression chamber is larger than the supply amount to the other compression chamber. The rotary compressor as described.
As the compression chamber, it has a first compression chamber formed outside the wrap of the orbiting scroll, and a second compression chamber formed inside the wrap of the orbiting scroll,
The supply amount of the refrigerating machine oil to the compression chamber having the higher volume change rate among the first compression chamber and the second compression chamber is larger than the supply amount to the other compression chamber. 4. The rotary compressor according to 4.
The first compression chamber oil supply path is provided on the back surface of the orbiting scroll and is provided with an introduction path portion through which refrigerating machine oil is introduced from the oil storage section, and is provided inside the wrap of the orbiting scroll and communicates with the introduction path section. The oil supply passage portion in the lap having an opening on the top surface of the lap, and a concave portion provided in the end plate of the fixed scroll and intermittently communicating with the opening of the oil supply passage portion in the lap. The rotary compressor according to any one of the above.
The refrigerant according to claim 1, wherein the refrigerant contains at least one of tetrafluoropropene or trifluoropropene which is a kind of hydrofluoroolefin, and has a global warming potential of 5 or more and 750 or less, preferably 5 or more and 350 or less. The rotary compressor according to any one of the above.
The refrigerant is mainly composed of tetrafluoropropene or trifluoropropene, which is a kind of hydrofluoroolefin,
The difluoromethane and pentafluoroethane are mixed with the refrigerant so that the global warming potential is 5 or more and 750 or less, preferably 5 or more and 350 or less. The rotary compressor described in 1.
The refrigerating machine oil comprises (1) polyoxyalkylene glycols, (2) polyvinyl ethers, (3) poly (oxy) alkylene glycol or a copolymer of its monoether and polyvinyl ether, (4) polyol esters and polycarbonate. A synthetic oil containing an oxygen-containing compound, (5) a synthetic oil mainly composed of alkylbenzenes, or (6) a synthetic oil mainly composed of α-olefins. The rotary compressor described in 1.