JP2006291970A - Multistage compression rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the startability of a compressor when using an inflammable refrigerant for an internal intermediate pressure type multistage compression rotary compressor. <P>SOLUTION: This multistage compression rotary compressor using the inflammable refrigerant as a refrigerant, discharges the refrigerant compressed by a first rotary compression element 32, into a sealed container 12 and compresses the discharged intermediate pressure refrigerant by a second rotary compression element 34, wherein a pressure equalizing valve 101 is provided for allowing the refrigerant discharge side of the second rotary compression element 34 and the inside of the sealed container 12 to communicate with each other when the pressure on the refrigerant discharge side of the second rotary compression element 34 becomes lower than the pressure in the sealed container 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes an electric element in a hermetic container and first and second rotary compression elements driven by a rotation shaft of the electric element, and the refrigerant compressed by the first rotary compression element is supplied to the second container. The present invention relates to a multistage compression rotary compressor that compresses with a rotary compression element.

  Conventionally, in this type of rotary compressor, as shown in Patent Document 1, refrigerant gas is sucked into the low pressure chamber side of the cylinder from the suction port of the rotary compression element, and is compressed by the operation of the roller and vane to be discharged on the high pressure chamber side of the cylinder. It is configured such that it is once discharged into the sealed container and discharged from the sealed container to the outside. The vane is movably mounted in a groove provided in the radial direction of the cylinder. Such a vane is pressed against a roller to divide the cylinder into a low pressure chamber side and a high pressure chamber side. A spring for urging the vane toward the roller is provided on the rear side of the vane, and a back pressure chamber communicating with the inside of the sealed container for urging the vane toward the roller is provided in the groove. And the high pressure in the airtight container is applied to the back pressure chamber to urge the vane toward the roller.

  On the other hand, in recent years, the use of flammable refrigerants such as HC refrigerants other than Freon, such as propane (R290), has also been studied in this type of rotary compressor due to the problem of ozone layer destruction by CFC refrigerants.

  By the way, it is necessary to reduce the amount of flammable refrigerant such as propane as much as possible because of safety problems. In general, when propane is used as a refrigerant, the safety limit is about 150 g. In practice, it is necessary to limit the amount to 100 g (50 g for a refrigerator) with a margin.

On the other hand, since the compressed refrigerant is discharged into the hermetic container in the rotary compressor, the amount of refrigerant to be sealed increases by about 30 g to 50 g as compared with a reciprocating type compressor having the same capacity. For this reason, the practical application of a rotary compressor using a flammable refrigerant has been very strict.
Japanese Patent No. 25007047

  Therefore, it has been studied to use a combustible refrigerant in a multistage compression rotary compressor in which the inside of the sealed container has an intermediate pressure. In this case, the pressure in the sealed container is lower than when high-pressure refrigerant is discharged into the sealed container. In other words, the lower the pressure, the lower the density of the refrigerant, so that the amount of refrigerant present in the sealed container is reduced, and the amount of refrigerant sealed in the sealed container can be reduced. In particular, when the ratio of the displacement volume of the second rotary compression element to the displacement volume of the first rotation compression element is increased, the intermediate pressure is less likely to increase, so that the amount of refrigerant sealed in the sealed container can be further increased. Can be reduced.

  However, in the case of the internal intermediate pressure type, since it takes time to reach the equilibrium pressure in the compressor after the rotary compressor is stopped, there is also a problem that startability deteriorates at the time of restart.

  The present invention was made to solve the problems of the related art, and aims to improve the startability of a compressor when a combustible refrigerant is used for an internal intermediate pressure type multistage compression rotary compressor. To do.

  That is, in the multistage compression rotary compressor according to claim 1 of the present invention, the combustible refrigerant is used as the refrigerant, the refrigerant compressed by the first rotary compression element is discharged into the sealed container, and the discharged intermediate pressure is reduced. When the refrigerant is compressed by the second rotary compression element and the pressure on the refrigerant discharge side of the second rotary compression element becomes lower than the pressure in the sealed container, the refrigerant discharge side of the second rotary compression element Since the pressure equalizing valve that communicates with the inside of the sealed container is provided, the pressure equalization in the sealed container can be accelerated after the compressor is stopped.

  According to the second aspect of the present invention, a cylinder constituting the second rotary compression element, a support member for closing the opening surface of the cylinder, and a refrigerant constituted in the support member and compressed in the cylinder are discharged. A discharge silencing chamber, a cover that partitions the discharge silencing chamber and the sealed container, and a pressure equalizing passage formed in the cover are provided. A pressure equalizing valve is provided in the discharge silencing chamber to open and close the pressure equalizing passage. Thus, the structure can be simplified and the space efficiency can be improved.

  According to the first aspect of the present invention, the combustible refrigerant is used as the refrigerant, the refrigerant compressed by the first rotary compression element is discharged into the sealed container, and the discharged intermediate pressure refrigerant is discharged to the second rotation. When the pressure is compressed by the compression element and the pressure on the refrigerant discharge side of the second rotary compression element becomes lower than the pressure in the sealed container, the refrigerant discharge side of the second rotary compression element communicates with the inside of the sealed container. Since the pressure equalizing valve is provided, after the compressor is stopped, the balance of the pressure in the first rotary compression element, the second rotary compression element, and the sealed container can be accelerated.

  As a result, the high-low pressure difference in the rotary compressor can be eliminated in a short time, and the startability of the rotary compressor can be remarkably improved.

  According to a second aspect of the present invention, a cylinder constituting the second rotary compression element, a support member that closes the opening surface of the cylinder, and a refrigerant that is configured in the support member and compressed in the cylinder are discharged. A discharge silencing chamber, a cover that partitions the discharge silencing chamber and the sealed container, and a pressure equalizing passage formed in the cover, and the pressure equalizing valve is provided in the discharge silencing chamber and is a pressure equalizing passage. As the door is opened and closed, productivity and space efficiency can be improved.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a longitudinal sectional view of an internal intermediate pressure type multi-stage (two-stage) compression rotary compressor 10 having first and second rotary compression elements 32 and 34 as an embodiment of the multi-stage compression rotary compressor of the present invention. ing.

  In FIG. 1, a rotary compressor 10 of the embodiment is an internal intermediate pressure type multi-stage compression rotary compressor that uses propane (R290) as a refrigerant. The multi-stage compression rotary compressor 10 includes a cylindrical sealed container 12A made of a steel plate, and The sealed container 12 as a case formed by a substantially bowl-shaped end cap (lid body) 12B that closes the upper opening of the sealed container 12A, and disposed and stored above the internal space of the container body 12A of the sealed container 12 And a rotary compression mechanism unit including a first rotary compression element 32 and a second rotary compression element 34 which are arranged below the electric element 14 and are driven by the rotary shaft 16 of the electric element 14. 18.

  The closed container 12 has an oil reservoir at the bottom. Further, a terminal (wiring is omitted) 20 for supplying electric power to the electric element 14 is attached to the side surface of the container body 12A.

  The electric element 14 includes a stator 22 that is annularly attached along the inner surface of the upper space of the hermetic container 12, and a rotor 24 that is inserted and installed with a slight gap inside the stator 22. A rotating shaft 16 extending in the vertical direction is fixed to the rotor 24.

  The stator 22 has a laminated body 26 in which donut-shaped electromagnetic steel plates are laminated, and a stator coil 28 wound by a distributed winding method. Similarly to the stator 22, the rotor 24 is also formed of a laminated body 30 of electromagnetic steel plates.

  An intermediate partition plate 36 is sandwiched between the first rotary compression element 32 and the second rotary compression element 34. That is, the first rotary compression element 32 and the second rotary compression element 34 include an intermediate partition plate 36, an upper cylinder (second cylinder) 38, a lower cylinder (first cylinder) 38 disposed above and below the intermediate partition plate 36. 1 cylinder) 40 and an upper roller (which is eccentrically rotated by being fitted to eccentric parts 42 and 44 provided on the rotary shaft 16 so as to rotate in the upper and lower cylinders 38 and 40 with a phase difference of 180 degrees. Second vane (second roller) 46, lower roller (first roller) 48, and vanes (second second) in contact with the upper and lower rollers 46, 48 to divide the upper and lower cylinders 38, 40 into a low pressure chamber side and a high pressure chamber side, respectively. As a support member that also serves as a bearing for the rotary shaft 16 by closing the upper opening surface of the upper cylinder 38 and the lower opening surface of the lower cylinder 40. Upper support member 54 and lower support part Constructed at 56.

  As shown in FIG. 2, guide grooves 70 and 72 for accommodating the vanes 50 and 52 are formed in the upper and lower cylinders 38 and 40 constituting the first and second rotary compression elements 32 and 34, respectively. On the outside of the guide grooves 70 and 72, that is, on the back side of the vanes 50 and 52, storage portions 70A and 72A for storing springs 74 and 76 as spring members are formed. The springs 74 and 76 are in contact with the rear end portions of the vanes 50 and 52, and always bias the vanes 50 and 52 toward the rollers 46 and 48. The storage portions 70A and 72A are open to the guide grooves 70 and 72 side and the closed container 12 (container body 12A) side, and the springs 74 and 76 stored in the storage portions 70A and 72A are connected to the closed container 12 side. Is provided with a plug (not shown) and serves to prevent the springs 74 and 76 from coming off. Further, an O-ring (not shown) is attached to the peripheral surface of the plug in order to seal between each plug and the inner surfaces of the accommodating portions 70A and 72A.

  Further, between the guide groove 70 and the accommodating portion 70A, the vane 50 is always urged to the roller 46 side together with the spring 74. Therefore, the second back which applies the refrigerant discharge pressure of the second rotary compression element 34 to the vane 50 is provided. A pressure chamber 80 is provided. The upper surface of the second back pressure chamber 80 communicates with a communication passage 90 described later. Further, the lower surface of the second back pressure chamber 80 communicates with a first back pressure chamber 82 described later through a communication hole 110 formed in the intermediate partition plate 36.

  In this way, by connecting the discharge silencer chamber 62 and the second back pressure chamber 80 through the communication passage 90, the high pressure pressure compressed by the second rotary compression element 34 and discharged into the discharge silencer chamber 62 is obtained. The refrigerant is added from the communication passage 90 to the second back pressure chamber 80. As a result, the vane 50 is sufficiently urged toward the roller 46, so that unstable operation behavior of the second rotary compression element 34 such as vane jumping can be avoided.

  Between the guide groove 72 for accommodating the vane 52 of the lower cylinder 40 and the accommodating portion 72A, the first back pressure chamber 82 described above for urging the vane 52 to the roller 48 side together with the spring 76 is provided. ing. The upper surface of the first back pressure chamber 82 communicates with the second back pressure chamber 80 through the communication hole 110 described above.

  In this way, the second back pressure chamber 80 and the first back pressure chamber 82 are communicated with each other through the communication hole 110, thereby allowing the discharge silencer chamber to be applied to the second back pressure chamber 80 through the communication path 90. The high pressure in 62 can be introduced into the first back pressure chamber 82. As a result, the vane 52 is sufficiently biased toward the roller 48, so that the pressure rise in the first back pressure chamber 82 is quick at the time of start-up, and the first rotary compression element 32 such as vane jumping is performed. Unstable driving behavior can be avoided.

  In particular, in the present invention, the inside of the sealed container 12 is set to an intermediate pressure, and the second rotary compression element 34 with respect to the excluded volume of the first rotary compression element 32 is set so that the intermediate pressure in the closed container 12 is lowered as will be described later. Since the ratio of the excluded volume is set to be large, it is difficult to increase the pressure in the hermetic container 12 when the rotary compressor 10 is started, so that it is possible to avoid the disadvantage that sufficient back pressure is not applied to the vane 52. It becomes like this. As a result, the reliability of the rotary compressor 10 can be improved.

  In addition, by simply forming the communication path 90 in the upper support member 54 and forming the communication hole 110 in the intermediate partition plate 36, sufficient back pressure can be applied to the vanes 50 and 52 without using a special mechanism. Therefore, the highly reliable rotary compressor 10 can be produced while reducing the processing cost.

  The upper and lower cylinders 38 and 40 are provided with suction passages 58 and 60 that communicate with the inside of the upper and lower cylinders 38 and 40, respectively, through a suction port (not shown). Further, the upper support member 54 is provided with a discharge silencer chamber 62 formed by blocking the refrigerant compressed in the upper cylinder 38 from the discharge port 39 with a cover serving as a wall from the upper support member 54. ing. That is, the discharge silencer chamber 62 is closed by the upper cover 66 as a wall that defines the discharge silencer chamber 62.

  The communication path 90 described above is formed in the upper support member 54. The communication passage 90 is a passage that connects the discharge silencing chamber 62 that communicates with the discharge port 39 of the upper cylinder 38 of the second rotary compression element 34 and the second back pressure chamber 80.

  Further, as shown in FIG. 3, the upper cover 66 is formed with a pressure equalizing passage 100 that allows the inside of the sealed container 12 and the inside of the discharge silencer chamber 62 to communicate with each other. The pressure equalizing passage 100 is a hole penetrating the upper cover 66 in the vertical direction, and the lower surface of the pressure equalizing passage 100 is closed by a pressure equalizing valve 101 mounted in the discharge silencer chamber 62 so as to be opened and closed.

  The pressure equalizing valve 101 is formed of an elastic member made of a vertically long, substantially rectangular metal plate. A backer valve 102 serving as a pressure equalizing valve restraining plate is disposed below the pressure equalizing valve 101, and the lower surface of the upper cover 66. Is attached. One side of the pressure equalizing valve 101 is in contact with the pressure equalizing passage 100 to be sealed, and the other side is fixed to the mounting hole 103 of the upper cover 66 provided with a predetermined distance from the pressure equalizing passage 100 by a caulking pin 104. Has been.

  When the pressure in the discharge silencer chamber 62 becomes lower than the pressure in the sealed container 12 after the rotary compressor 10 is stopped, the pressure in the sealed container 12 pushes the pressure equalizing valve 101 that closes the pressure equalizing passage 100 from above in FIG. The pressure equalizing passage 100 is opened and discharged to the discharge silencer chamber 62. At this time, since the pressure equalizing valve 101 is fixed to the upper cover 66 on the other side, one side contacting the pressure equalizing passage 100 warps and contacts the backer valve 102 that regulates the opening amount of the pressure equalizing valve. When the pressure in the discharge silencing chamber 62 becomes equal to or higher than the pressure in the sealed container 12, the pressure equalizing valve 101 moves away from the backer valve 102 and closes the pressure equalizing passage 100.

  As described above, when the pressure in the discharge muffler chamber 62 becomes lower than the pressure in the sealed container 12, the pressure equalizing passage 100 is opened and discharged to the discharge muffler chamber 62. The inconvenience that the intermediate pressure is difficult to decrease can be avoided. Thereby, the pressure equalization in the discharge silencing chamber 62 and the sealed container 12 can be accelerated.

  Furthermore, since the pressure equalizing valve 101 is provided in the discharge silencing chamber 62, interference does not occur even if the upper electric element 14 is brought close to the upper cover 66. Accordingly, space efficiency is improved and the rotary compressor 10 can be reduced in size. Further, since the pressure equalizing valve 101 is attached to the lower surface of the upper cover 66, the attaching operation can be easily performed.

  A discharge valve 127 that closes the discharge port 39 so as to be openable and closable is provided on the lower surface of the discharge silencer chamber 62 (not shown in FIGS. 1 and 2). The discharge valve 127 is composed of an elastic member made of a vertically long, substantially rectangular metal plate. A backer valve 128 serving as a discharge valve restraining plate is disposed above the discharge valve 127 and is attached to the upper support member 54. It has been. One side of the discharge valve 127 abuts on the discharge port 39 to be sealed, and the other side is fixed to the mounting hole 129 of the upper support member 54 provided at a predetermined distance from the discharge port 39 by the caulking pin 130. ing.

  Then, the refrigerant gas that has been compressed in the upper cylinder 38 and has reached a predetermined pressure pushes up the discharge valve 127 that closes the discharge port 39 from below in the drawing to open the discharge port 39 and discharge it to the discharge silencing chamber 62. . At this time, since the other side of the discharge valve 127 is fixed to the upper support member 54, one side in contact with the discharge port 39 is warped, and the discharge valve 127 contacts a backer valve (not shown) that regulates the opening amount of the discharge valve 127. Touch. When it is time to finish the discharge of the refrigerant gas, the discharge valve 127 is separated from the backer valve, and the discharge port 39 is closed.

  On the other hand, the refrigerant gas compressed in the lower cylinder 40 is discharged from a discharge port (not shown) into a discharge silencer chamber 64 formed on the side opposite to the electric element 14 of the lower support member 56 (the bottom side of the sealed container 12). . The discharge silencing chamber 64 has a hole through which the lower shaft 56 and the lower support member 56 that also serves as a bearing of the rotary shaft 16 penetrate, and the lower support member 56 is opposite to the electric element 14. It is comprised by the cup 65 to cover.

  In this case, a bearing 54 </ b> A is formed upright at the center of the upper support member 54. A bearing 56A is formed through the center of the lower support member 56, and the rotary shaft 16 is held by a bearing 54A of the upper support member 54 and a bearing 56A of the lower support member 56.

  The discharge silencer chamber 64 of the first rotary compression element 32 and the inside of the sealed container 12 are communicated with each other through a communication path. The communication path includes a lower support member 56, an upper support member 54, an upper cover 66, and upper and lower cylinders. 38 and 40 are holes (not shown) penetrating the intermediate partition plate 36. In this case, an intermediate discharge pipe 121 is erected at the upper end of the communication path, and an intermediate pressure refrigerant is discharged from the intermediate discharge pipe 121 into the sealed container 12.

  As described above, since the intermediate pressure refrigerant gas compressed by the first rotary compression element 32 is discharged into the sealed container 12, compared with the case where high-pressure refrigerant is discharged into the sealed container 12, The amount of refrigerant discharged is reduced. That is, the lower the pressure, the lower the density of the refrigerant, so that the medium pressure refrigerant discharged into the sealed container 12 has a lower refrigerant gas density than the high pressure refrigerant discharged into the sealed container 12, The amount of refrigerant present in the sealed container 12 is reduced.

  This will be described with reference to FIGS. 4 and 5. FIG. FIG. 4 shows the suction pressure (low pressure) of the first rotary compression element 32 of the internal intermediate pressure type multistage compression rotary compressor 10 of the present invention with respect to the refrigerant evaporation temperature, the intermediate pressure (case internal pressure) in the sealed container 12, 2 shows the high pressure (discharge pressure) discharged by the rotary compression element 34, and FIG. 5 shows the suction pressure and the high pressure (case internal pressure) with respect to the evaporation temperature when the same high pressure is discharged into the sealed container in the case of a single cylinder rotary compressor. ). As is apparent from both figures, in the internal intermediate pressure type multi-stage compression rotary compressor 10 of the present invention, the pressure in the hermetic container is significantly lower than that in the case of a single cylinder rotary compressor. For this reason, the amount of refrigerant sealed in the sealed container 12 can be reduced.

  Furthermore, in the embodiment, the ratio of the displacement volume of the second rotary compression element 34 to the displacement volume of the first rotation compression element 32 is increased, for example, the second rotation compression with respect to the displacement volume of the first rotation compression element 32. The ratio of the excluded volume of the element 34 is set to 60% or more and 90% or less. FIG. 5B shows the intermediate pressure at 60%, and A shows the intermediate pressure at 90%.

  In the conventional multi-stage compression type rotary compressor, the ratio of the displacement volume of the second rotary compression element 34 to the displacement volume of the first rotation compression element 32 is about 57%. As a result, the density of the refrigerant discharged into the hermetic container 12 also increases, so the amount of refrigerant enclosed in the rotary compressor 10 must be increased. However, as in the embodiment, the first rotary compression element If the ratio of the excluded volume of the second rotary compression element 34 to the excluded volume of 32 is 60% or more, the amount of refrigerant in the sealed container 12 is reduced.

  Further, when the ratio of the excluded volume of the second rotary compression element 34 to the first rotary compression element 32 is larger than 90%, the refrigerant sucked into the first rotary compression element as is apparent from FIG. Pressure (suction pressure) and the intermediate pressure in the sealed container 12 are almost the same pressure, so that the first rotary compression element 32 is not sufficiently compressed, or the biasing force of the vanes of the first rotary compression element 32 There is a shortage of vanes. Further, there arises a problem that the behavior of the rotary compressor 10 becomes unstable, such as the fact that the differential pressure oil supply of the oil from the oil reservoir provided at the inner bottom portion of the sealed container 12 cannot be sufficiently performed.

  Accordingly, by setting the ratio of the excluded volume of the second rotary compression element 34 to the first rotary compression element 32 to be 60% or more and 90% or less as in the embodiment, vane jumping of the second rotary compression element 34 and the like. While avoiding unstable driving behavior, the first-stage differential pressure (the suction pressure (suction pressure) of the first rotary compression element 32 and the discharge pressure (intermediate pressure) of the first rotary compression element 32) is reduced. Thus, the density of the refrigerant gas discharged into the sealed container 12 can be lowered.

  In other words, since the density of the gas discharged into the sealed container 12 is reduced, the amount of refrigerant gas in the sealed container 12 can be further reduced. The amount can be reduced.

  The upper cover 66 defines a discharge silencing chamber 62 that communicates with the inside of the upper cylinder 38 of the second rotary compression element 34 at the discharge port 39. The electric element 14 is provided. The upper cover 66 is formed of a substantially donut-shaped circular steel plate in which a hole through which the bearing 54A of the upper support member 54 passes is formed.

  In this case, propane (R290), which is a combustible refrigerant, is used as the refrigerant in this case. As other combustible refrigerants applicable to the present invention, methane (R50) and ethane (R170), which are refrigerants classified as high combustibility (Level 3) based on isobutane (R600a) and ASHRAE Std 34 Safety group. ), Propane (R290), butane (R600), propylene (R1270) and the like.

  Further, the side surface of the container body 12A of the sealed container 12 corresponds to the suction passages 58 and 60 of the cylinders 38 and 40, the opposite side of the suction passage 58 of the cylinder 38, and the lower side of the rotor 24 (just below the electric element 14). The sleeves 141, 142, 143, and 144 are fixed by welding at the positions where they are placed. The sleeves 141 and 142 are adjacent to each other vertically, and the sleeve 143 is substantially diagonal to the sleeve 141. The sleeve 144 is located above the sleeve 141.

  One end of a refrigerant introduction pipe 92 for introducing refrigerant gas into the upper cylinder 38 is inserted into and connected to the sleeve 141, and one end of the refrigerant introduction pipe 92 communicates with the suction passage 58 of the upper cylinder 38. The refrigerant introduction pipe 92 passes through the outside of the sealed container 12 to reach the sleeve 144, and the other end is inserted and connected into the sleeve 144 to communicate with the sealed container 12.

  In addition, one end of a refrigerant introduction pipe 94 for introducing refrigerant gas into the lower cylinder 40 is inserted and connected in the sleeve 142, and one end of the refrigerant introduction pipe 94 communicates with the suction passage 60 of the lower cylinder 40. In addition, a refrigerant discharge pipe 96 is inserted and connected into the sleeve 143, and one end of the refrigerant introduction pipe 96 communicates with the discharge silencer chamber 62.

  Next, the operation of the above configuration will be described. When commercial power is supplied to the stator coil 28 of the electric element 14 via the terminal 20 and a wiring (not shown), the electric element 14 is activated and the rotor 24 rotates. By this rotation, the upper and lower rollers 46 and 48 are eccentrically rotated in the upper and lower cylinders 38 and 40 by being fitted to the upper and lower eccentric portions 42 and 44 provided integrally with the rotary shaft 16.

  As a result, the low pressure (the suction pressure of the first rotary rotation compression element 32) sucked from the suction port (not shown) to the low pressure chamber side of the lower cylinder 40 via the refrigerant introduction pipe 94 and the suction passage 60 formed in the cylinder 40. : 380 KPa) refrigerant is compressed by the operation of the roller 48 and the vane 52 to become an intermediate pressure, and from the high pressure chamber side of the lower cylinder 40, the discharge port (not shown) and the discharge silencer chamber 64 formed in the lower support member 56 are not shown. The liquid is discharged from the intermediate discharge pipe 121 into the sealed container 12 through the passage. As a result, the inside of the sealed container 12 has an intermediate pressure (the discharge pressure of the first rotary compression element 32: the excluded volume ratio of the second rotary compression element 34 to the excluded volume of the first rotary compression element 32 is 60%. Is 710 KPa, and 450 KPa) when the ratio of the displacement volume of the second rotary compression element 34 to the displacement volume of the first rotation compression element 32 is 90%.

  Then, the intermediate-pressure refrigerant gas in the sealed container 12 exits from the sleeve 144 and passes through a refrigerant introduction pipe 92 and a suction passage 58 formed in the cylinder 38 from a suction port (not shown) to the low pressure chamber side of the upper cylinder 38. Inhaled. The sucked intermediate-pressure refrigerant gas is compressed in the second stage by the operation of the roller 46 and the vane 50 to become a high-temperature and high-pressure refrigerant gas (discharge pressure (high pressure) of the second rotary compression element 34: 1890 KPa). ). As a result, the discharge valve 127 provided in the discharge silencer chamber 62 is opened, and the discharge silencer chamber 62 and the discharge port 39 communicate with each other. Therefore, the upper support member passes through the discharge port 39 from the high pressure chamber side of the upper cylinder 38. The ink is discharged into a discharge silencer chamber 62 formed in 54.

  A part of the high-pressure refrigerant gas discharged to the discharge silencer chamber 62 flows into the second back pressure chamber 80 from the communication passage 90 described above, and biases the vane 50 toward the roller 46 side. Further, the air flows into the first back pressure chamber 82 through the communication hole 110 formed in the intermediate partition plate 36 and urges the vane 52 toward the roller 48 side. On the other hand, the other refrigerant gas discharged into the discharge silencer chamber 62 is discharged to the outside through the refrigerant discharge pipe 96.

  Here, when the operation of the rotary compressor 10 is stopped, the discharge silencing chamber 62 and the second back pressure chamber 80 of the second rotary compression element 34 are communicated with each other through the communication passage 90, and the first rotary compression element 32 Since the first back pressure chamber 82 and the second back pressure chamber 80 of the second rotary compression element 34 are communicated with each other through the communication hole 110, the vanes 50 and 52 are guided from these back pressure chambers 80 and 82. The high-pressure refrigerant gas in the cylinder 38 is bypassed to the cylinder 40 through the grooves 70 and 72 and the gaps between the springs 74 and 76 and the storage portions 70A and 72A. Thereby, the high-pressure refrigerant gas in the cylinder 38 reaches the equilibrium pressure in a short time.

  Further, after the rotary compressor 10 is stopped, when the pressure in the discharge silencing chamber 62 decreases and becomes lower than the pressure in the sealed container 12, the pressure equalizing valve 101 is pushed downward by the pressure in the sealed container 12 as described above and is used for pressure equalization. The passage 100 is opened. As a result, the intermediate-pressure refrigerant gas in the sealed container 12 flows into the discharge silencing chamber 62.

  When the pressure in the discharge silencing chamber 62 rises due to the introduction of such pressure, and the pressure in the discharge silencing chamber 62 becomes the same as the pressure in the sealed container 12, the pressure equalizing valve 101 closes the pressure equalizing passage 100 as described above. On the other hand, the discharge silencing chamber 62 and the back pressure chambers 80 and 82 communicate with each other through the communication passage 90 and the communication hole 110, so that the inside of the sealed container 12, the discharge silencing chamber 62, and the back pressure chambers 80 and 82 are communicated. The pressure in each cylinder 40, 38 will quickly equilibrate. Therefore, the startability at the next restart is improved.

  In this way, the combustible refrigerant is used as the refrigerant, the refrigerant compressed by the first rotary compression element 32 is discharged into the sealed container 12, and the discharged intermediate pressure refrigerant is discharged by the second rotary compression element 34. While compressing, the discharge silencing chamber 62 of the second rotary compression element 34 and the second back pressure chamber 80 are communicated with each other through the communication passage 90, and further, the second back pressure chamber 80 and the first back pressure chamber 82 are communicated. Are communicated with each other through the communication hole 110 formed in the intermediate partition plate 36, the high-pressure refrigerant gas in the discharge silencing chamber 62 is added to the first and second back pressure chambers 80 and 82.

  As a result, even when the internal intermediate pressure type rotary compressor 10 is used, the vanes 50 and 52 are sufficiently biased toward the rollers 46 and 48, so that the first and second rotary compression elements such as vane jumps are obtained. The unstable driving behaviors 32 and 34 can be avoided.

  In particular, in the present invention, the inside of the sealed container 12 is set to an intermediate pressure, and the second rotary compression element 34 with respect to the excluded volume of the first rotary compression element 32 is set so that the intermediate pressure in the closed container 12 is lowered as will be described later. Since the ratio of the excluded volume is set to be large, the pressure in the hermetic container 12 increases when the rotary compressor 10 is started, but is discharged from the second rotary compression element 34 into the back pressure chambers 80 and 82. Therefore, a sufficient back pressure is applied to the vane 52 from the start, and the reliability of the rotary compressor 10 can be improved.

  In addition, after the operation of the rotary compressor 10 is stopped, the discharge silencing chamber 62 and the second back pressure chamber 80 communicate with each other through the communication passage 90 as described above, and the second back pressure chamber 80 and the first back pressure chamber 80 communicate with each other. The back pressure chamber 82 is communicated with the communication hole 110, and the inside of the sealed container 12 and the discharge silencing chamber 62 are communicated with each other through the pressure equalizing passage 100, so that the inside of the rotary compressor 10 reaches an equilibrium pressure. Can be accelerated.

  Thereby, the differential pressure in the rotary compressor 10 can be eliminated in a short time, and the startability of the rotary compressor 10 can be remarkably improved.

  In the embodiment, the multi-stage compression rotary compressor 10 with the rotary shaft 16 as a vertical type has been described. However, it goes without saying that the present invention can also be applied to a multi-stage compression rotary compressor with a rotary shaft as a horizontal type.

  Further, the multi-stage compression rotary compressor has been described with the two-stage compression rotary compressor including the first and second rotary compression elements. However, the rotary compression element is not limited to this, and the rotary compression element has three, four or more rotary compressions. The present invention can be applied to a multi-stage compression rotary compressor having elements.

It is a longitudinal cross-sectional view of the internal intermediate pressure type multistage compression type rotary compressor of the Example of this invention. It is an expansion longitudinal cross-sectional view of the 1st and 2nd rotary compression mechanism part of the internal intermediate pressure type multistage compression type rotary compressor of this invention. It is an expansion longitudinal cross-sectional view of the discharge silencing chamber of the 2nd rotation compression element of this invention. It is a figure which shows the relationship between the suction pressure with respect to the evaporation temperature, the intermediate pressure, and the high pressure in the internal intermediate pressure type multistage compression rotary compressor of the present invention. It is a figure which shows the relationship between the suction pressure with respect to the evaporation temperature in a single cylinder rotary compressor, and a high pressure | voltage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Multistage compression rotary compressor 12 Airtight container 14 Electric element 16 Rotating shaft 18 Rotation compression mechanism part 22 Stator 24 Rotor 26 Laminated body 28 Stator coil 30 Laminated body 32 1st rotation compression element 34 2nd rotation compression element 38,40 Cylinder 54 Upper support member 56 Lower support member 62, 64 Discharge silencer chamber 65 Cup 66 Upper cover 80 Second back pressure chamber 82 First back pressure chamber 90 Communication passage 100 Pressure equalizing passage 101 Pressure equalizing valve 110 Communication hole

Claims (2)

An electric element and first and second rotary compression elements driven by a rotary shaft of the electric element are provided in the sealed container, and the refrigerant compressed by the first rotary compression element is supplied to the second rotary compression element. In a multistage compression rotary compressor that compresses with elements,
A combustible refrigerant is used as the refrigerant, the refrigerant compressed by the first rotary compression element is discharged into the sealed container, and the discharged intermediate pressure refrigerant is compressed by the second rotary compression element. A pressure equalizing valve for communicating between the refrigerant discharge side of the second rotary compression element and the inside of the sealed container when the pressure on the refrigerant discharge side of the second rotary compression element becomes lower than the pressure in the closed container. A multi-stage compression rotary compressor characterized by comprising: A cylinder constituting the second rotary compression element;
A support member for closing the opening surface of the cylinder;
A discharge silencer chamber configured in the support member, in which refrigerant compressed in the cylinder is discharged;
A cover that partitions the discharge silencer chamber and the sealed container;
A pressure equalizing passage formed in the cover,
2. The multistage compression rotary compressor according to claim 1, wherein the pressure equalizing valve is provided in the discharge silencing chamber to open and close the pressure equalizing passage.

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