Multistage compression type rotary compressor

The present invention relates to a multi-stage compression type rotary compressor in which an intermediate pressure refrigerant gas compressed by a first rotational compression element and discharged into a closed container is sucked into a second rotational compression element, compressed and discharged. is there.

Conventionally, in this type of multi-stage compression type rotary compressor, especially in the internal intermediate pressure type multi-stage compression type rotary compressor, the refrigerant gas is sucked into the low pressure chamber of the cylinder from the suction port of the first rotational compression element and compressed by the operation of the rollers and vanes. The pressure becomes intermediate and is discharged from the high pressure chamber of the cylinder through the discharge port and the discharge muffling chamber into the closed container. Then, the intermediate pressure refrigerant in this closed container is sucked into the low pressure chamber of the cylinder from the suction port of the second rotational compression element, and the second stage compression is performed by the operation of the rollers and vanes to perform the high temperature and high pressure refrigerant gas. It is configured to be discharged from the high pressure chamber through the discharge port and the discharge muffling chamber.

Each of the vanes is movably inserted into a guide groove provided in the radial direction of the cylinder, and a back pressure chamber is formed on the rear side of each vane. The intermediate pressure in the closed container is applied to the back pressure chamber of the first rotational compression element, and the high pressure, which is the pressure on the refrigerant discharge side of the second rotational compression element, is applied to the back pressure chamber of the second rotational compression element. Has been applied. Then, the vane of the first rotational compression element is urged toward the roller side by the spring provided in the back pressure chamber on the rear side of the vane and the intermediate pressure applied to the back pressure chamber, and the second rotation The vane of the compression element was urged toward the roller side by a spring provided in the back pressure chamber on the rear side of the vane and a high pressure applied to the back pressure chamber (see, for example, Patent Document 1).<patcit num="1"><text>Japanese Unexamined Patent Publication No. 2003-172280</text></patcit>

<p> By the way, in such a multi-stage compression type rotary compressor, there is a problem that a so-called pressure reversal phenomenon occurs in which the discharge pressure (intermediate pressure) of the first rotary compression element and the discharge pressure (high pressure) of the second rotary compression element are reversed. Was occurring. The pressure reversal phenomenon may occur in a situation where the refrigerant can be sufficiently compressed only by the compression work in the first rotational compression element when the rotary compressor is lightly loaded. In this case, since the second rotational compression element does not substantially perform the compression work, the flow resistance in the process until the refrigerant discharged from the first rotational compression element flows to the discharge side of the second rotational compression element. Since the pressure drops due to such factors, the discharge side pressure of the second rotational compression element becomes lower than the discharge side pressure of the first rotational compression element.</p><p> Further, when the evaporation temperature of the refrigerant rises at a high outside air temperature, the suction pressure of the first rotational compression element rises, so that the discharge pressure of the first rotary compression element also rises. On the other hand, the discharge pressure (high pressure) of the second rotational compression element is regulated so as not to rise above a preset pressure due to the rotation speed or the like, and thus is the discharge pressure of the first rotational compression element. When the intermediate pressure rises, pressure reversal may occur in which the pressure between the intermediate pressure and the high pressure is reversed.</p><p> In this way, when the discharge pressure of the first rotational compression element and the discharge pressure of the second rotational compression element are reversed, the pressure in the cylinder of the second rotational compression element (the refrigerant sucked into the second rotational compression element). Pressure (intermediate pressure)) rises above the discharge pressure (high pressure) of the second rotational compression element applied as the back pressure of the vane. There was a problem that vane skipping of the second rotational compression element occurred, causing noise and unstable operation of the second rotational compression element.</p><p> Further, even when there is no pressure reversal phenomenon as described above, when the discharge pressure of the first rotational compression element and the discharge pressure of the second rotational compression element are substantially the same, the vane is urged toward the roller side. Since the urging force is reduced, vane skipping may occur depending on the operating conditions (transitional time, etc.).</p><p> The present invention has been made to solve the problems of the prior art, and eliminates the pressure reversal of the discharge pressure of the first rotational compression element and the discharge pressure of the second rotational compression element to ensure stable operation. It is an object of the present invention to provide a multi-stage compression type rotary compressor that can be realized.</p>

<p> The multi-stage compression type rotary compressor of the present invention includes a driving element and first and second rotational compression elements driven by the driving element in a closed container.<u style="single">1st and</u>The second rotational compression element is a roller that is fitted to an eccentric portion formed on the rotating shaft of the cylinder and the driving element and rotates eccentrically in the cylinder, and a low-pressure chamber and a high-pressure chamber in the cylinder that come into contact with the roller. With vanes<u style="single">, From the support member that closes the opening surface of each cylinder and also serves as the bearing of the rotating shaft.</u>The pressure on the refrigerant discharge side of the second rotational compression element is configured.<u style="single">Of the second rotational compression element</u>It is applied as the back pressure of the vane, compressed by the first rotational compression element, and the intermediate pressure refrigerant gas discharged into the closed container is sucked into the second rotational compression element, compressed and discharged. There,<u style="single">A valve storage chamber formed in the cylinder of the first rotational compression element and opened in the closed container and a valve storage chamber that is movably stored in the valve storage chamber, and the pressure of the space in the closed container is applied to one surface. A valve device, a first communication hole formed through the cylinder of the first rotational compression element corresponding to the valve storage chamber, and a support member of the first rotational compression element corresponding to the first communication hole. The communication groove that communicates the suction passage of the first rotational compression element and the communication hole, and the vane back pressure chamber and the valve storage chamber of the second rotational compression element are communicated with each other, and the other side of the valve device. The valve device is provided with a second communication hole for applying the back pressure of the vane on one surface of the valve storage chamber when the pressure of the space in the closed container applied to one surface reaches a predetermined upper limit value. , The suction passage of the first rotational compression element and the inside of the closed container are communicated through the first communication hole and the communication groove, and the back pressure chamber, the valve storage chamber and the suction passage are arranged in the direction of the rotation axis. Is located in</u>It is characterized by that.</p>

<p> According to the present invention, a driving element and first and second rotational compression elements driven by the driving element are provided in a closed container.<u style="single">1st and</u>The second rotational compression element is a roller that is fitted to an eccentric portion formed on the rotating shaft of the cylinder and the driving element and rotates eccentrically in the cylinder, and a low-pressure chamber and a high-pressure chamber in the cylinder that come into contact with the roller. With vanes<u style="single">, From the support member that closes the opening surface of each cylinder and also serves as the bearing of the rotating shaft.</u>The pressure on the refrigerant discharge side of the second rotational compression element is configured.<u style="single">Of the second rotational compression element</u>Multi-stage compression that is applied as the back pressure of the vane, compressed by the first rotational compression element, and the intermediate pressure refrigerant gas discharged into the closed container is sucked into the second rotational compression element, compressed and discharged. In the type rotary compressor<u style="single">A valve storage chamber formed in the cylinder of the first rotational compression element and opened in the closed container, and the valve storage chamber are movably stored in the valve storage chamber, and the pressure in the space inside the closed container is applied to one surface. A valve device, a first communication hole formed through the cylinder of the first rotational compression element corresponding to the valve storage chamber, and a support member of the first rotational compression element corresponding to the first communication hole. The communication groove that communicates the suction passage of the first rotational compression element and the communication hole, and the vane back pressure chamber and the valve storage chamber of the second rotational compression element are communicated with each other, and the other side of the valve device. The valve device is provided with a second communication hole for applying the back pressure of the vane on one surface of the valve storage chamber when the pressure of the space in the closed container applied to one surface reaches a predetermined upper limit value. Communicates between the suction passage of the first rotational compression element and the inside of the closed container through the first communication hole and the communication groove.</u>Therefore, for example, the pressure on the refrigerant discharge side of the second rotational compression element, which is the vane back pressure, is set as the upper limit value, and the pressure in the airtight container applied to one surface of the valve device is equal to or higher than this upper limit value. When the pressure, that is, the pressure on the refrigerant discharge side of the first rotational compression element rises, or when the pressure before reaching the vane back pressure rises to this upper limit value as the upper limit value,<u style="single">Communicates the suction passage of the first rotational compression element with the inside of the closed container</u>If so, the refrigerant gas in the closed container can be released to the refrigerant suction side of the first rotational compression element.</p><p> As a result, the pressure of the refrigerant gas in the closed container, that is, the pressure on the refrigerant discharge side of the first rotational compression element is always equal to or lower than the pressure on the refrigerant discharge side of the second rotational compression element, or lower than the pressure. Therefore, it is possible to eliminate the pressure reversal between the refrigerant gas compressed by the first rotational compression element and the refrigerant gas compressed by the second rotational compression element. Therefore, it is possible to eliminate the vane skipping of the second rotational compression element and the unstable operating condition at an early stage, or to avoid it in advance.</p><p> Therefore, it is possible to eliminate the inconvenience that the second rotational compression element falls into an unstable operating condition, realize stable operation of the multi-stage compression type rotary compressor, and also realize noise reduction. become able to. In particular, since the valve device is operated by the vane back pressure and the pressure inside the closed container, which cause vane skipping,<u style="single">Communication control between the suction passage of the first rotational compression element and the inside of the closed container</u>Will be able to be performed more accurately.<u style="single">In this case, the back pressure chamber, the valve storage chamber, and the suction passage are arranged so as to be arranged in the direction of the rotation axis, so that the back pressure chamber and the valve storage chamber, and the valve storage chamber and the suction passage are communicated with each other at the shortest distance. You will be able to</u>It is also possible to simplify the structure.</p>

The present invention is a multi-stage compression type rotary compressor in which an intermediate pressure refrigerant gas compressed by a first rotational compression element and discharged into a closed container is sucked into a second rotational compression element, compressed and discharged. This is done to eliminate the inconvenience that the second rotational compression element causes vane jumping due to the pressure reversal of the intermediate pressure and causes noise, or the second rotational compression element falls into an unstable operating condition. Is. For the purpose of eliminating vane jumping in the second rotational compression element and unstable operating conditions, a communication passage that connects the space inside the closed container and the refrigerant suction side of the first rotational compression element, and this A valve device for opening and closing the communication passage is provided, and when the intermediate pressure in the closed container reaches a predetermined upper limit value, the communication passage is opened by the valve device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal side view and a view of an internal intermediate pressure type multi-stage (two-stage) compression type rotary compressor 10 provided with first and second rotational compression elements 32 and 34 as an example of the multi-stage compression type rotary compressor of the present invention. 2 and FIG. 3 are enlarged longitudinal side views of the upper vane 50 portion of the second rotational compression element 34 of the rotary compressor 10 of FIG.

In each figure, the rotary compressor 10 of the embodiment is compressed by the first rotational compression element 32, and the intermediate pressure refrigerant gas discharged into the closed container 12 is sucked into the second rotational compression element 34 and compressed. It is an internal intermediate pressure type multi-stage compression type rotary compressor that discharges. The rotary compressor 10 is a rotational compression mechanism unit including an electric element 14 as a driving element in a closed container 12, a first rotational compression element 32 and a second rotational compression element 34 driven by the electric element 14. It is composed of 18.

The closed container 12 has a container body 12A that houses the electric element 14 and the rotational compression mechanism 18 with the bottom as an oil reservoir, and a substantially bowl-shaped end cap (lid) 12B that closes the upper opening of the container body 12A. A circular mounting hole 12D is formed on the upper surface of the end cap 12B, and a terminal (wiring omitted) 20 for supplying power to the electric element 14 is mounted on the mounting hole 12D. ing.

The electric element 14 is composed of a stator 22 which is welded and fixed in an annular shape along the inner peripheral surface of the closed container 12 and a rotor 24 which is inserted and installed inside the stator 22 at a slight interval. , The rotor 24 is fixed to a rotating shaft 16 that passes through the center and extends in the vertical direction.

The stator 22 has a laminated body 26 in which donut-shaped electromagnetic steel plates are laminated, and a stator coil 28 wound around the teeth of the laminated body 26 by a series winding (concentrated winding) method. Further, the rotor 24 is also formed of a laminated body 30 of electromagnetic steel plates like the stator 22.

Further, the rotational compression mechanism unit 18 is composed of a first rotational compression element 32 and a second rotational compression element 34, and an intermediate partition plate 36 sandwiched between both rotational compression elements 32 and 34. .. In this embodiment, the first rotational compression element 32 is arranged on the lower side of the intermediate partition plate 36, and the second rotational compression element 34 is arranged on the upper side of the intermediate partition plate 36. The first rotational compression element 32 is fitted into the lower cylinder 40 arranged on the lower surface of the intermediate partition plate 36 and the eccentric portion 44 formed on the rotating shaft 16 of the electric element 14, and is eccentric in the lower cylinder 40. The rotating lower roller 48, the lower vane (not shown) that abuts on the lower roller 48 and divides the inside of the lower cylinder 40 into a low pressure chamber and a high pressure chamber, and the opening surface on the lower side of the lower cylinder 40 are closed. It is composed of a lower support member 56 that also serves as a bearing for the rotating shaft 16. Here, the low-pressure chamber in the lower cylinder 40 is a space surrounded by the lower vane, the lower roller 48, and the lower cylinder 40, and is an area where the suction port 161 exists, and the high-pressure chamber is the lower vane and the lower. This is the area where the discharge port (not shown) exists in the space surrounded by the roller 48 and the lower cylinder 40.

The second rotational compression element 34 is arranged on the upper surface of the intermediate partition plate 36, and is formed on the upper cylinder 38 as a cylinder for forming the second rotational compression element 34 and the rotary shaft 16 of the electric element 14. As an upper roller 46 as a roller that is fitted to the eccentric portion 42 and rotates eccentrically in the upper cylinder 38, and as a vane that contacts the upper roller 46 and divides the inside of the upper cylinder 38 into a low pressure chamber and a high pressure chamber. It is composed of an upper vane 50 and an upper support member 54 that closes the upper opening surface of the upper cylinder 38 and also serves as a bearing for the rotating shaft 16. Further, the eccentric portion 44 of the first rotational compression element 32 and the eccentric portion 42 of the second rotational compression element 34 are provided in the cylinders 38 and 49 with a phase difference of 180 degrees. The low-pressure chamber of the upper cylinder 38 is a space surrounded by the upper vane 50, the upper roller 46, and the upper cylinder 38, and is an area where a suction port (not shown) exists. This is the area where the discharge port (not shown) exists in the space surrounded by the vane 50, the upper roller 46, and the upper cylinder 38.

A guide groove 70 (only the guide groove of the upper vane 50 is shown) for accommodating the upper vane 50 and the lower vane is formed in the upper and lower cylinders 38 and 40, respectively, and the outside of the guide groove 70, that is, the back surface of the upper vane 50. the side, an accommodating portion for accommodating a spring 74 as a spring member back pressure chamber 70A of and is formed. This spring 74 abuts on the rear end of the vane 50 and constantly urges the vane 50 toward the roller 46. The back pressure chamber 70A is open to the guide groove 70 side and the closed container 12 (container body 12A) side, and a plug 75 is provided on the closed container 12 side of the spring 74 housed in the back pressure chamber 70A. It acts as a retainer for the spring 74 (same for the lower vane so far). An O-ring (not shown) is attached to the peripheral surface of the plug 75 of the spring 74 to seal between the plug 75 and the inner surface of the back pressure chamber 70A, and the pressure inside the closed container 12 is the back pressure chamber 70A. It is configured so that it does not flow inside.

Further, the back pressure chamber 70A is communicated with a discharge muffling chamber 62, which will be described later, via a pressure passage 100 formed in the upper support member 54, and the back pressure chamber 70A has a second rotational compression element 34. High-pressure PH (the pressure on the discharge side of the second rotational compression element 34 compressed by the second rotational compression element 34 and discharged to the discharge muffling chamber 62), which is the discharge pressure, is supplied. That is, a high pressure, which is the discharge side pressure of the second rotational compression element 34, is applied to the upper vane 50 of the second rotational compression element 34 as a back pressure.

The peripheral surface of the spring plug of the lower vane is not sealed, so that the back pressure chamber of the lower vane is sealed with the intermediate pressure PM (compressed by the first rotational compression element 32) in the airtight container 12. The pressure discharged into the container 12) is supplied. That is, an intermediate pressure, which is the discharge side pressure of the first rotational compression element 32, is applied as a back pressure to the lower vane of the first rotational compression element 32.

The upper support member 54 and the lower support member 56 have suction passages 162 (for the lower support member 56 and the lower cylinder 40) that communicate with the insides of the upper and lower cylinders 38 and 40 by suction ports 161 formed in the upper and lower cylinders 38 and 40, respectively. Only shown) is provided. Further, the upper support member 54 has a part of a surface (upper surface) opposite to the surface that comes into contact with the upper cylinder 38, and is formed by closing the recessed portion with the upper cover 66 as described above. A discharge muffling chamber 62 is provided.

On the lower surface of the discharge muffling chamber 62, a discharge valve 127 (described later) that closes the upper cylinder 38 discharge port so as to be openable and closable.<u style="single">Reference example</u>(Shown in Fig. 4) explained in. Then, the refrigerant gas compressed in the upper cylinder 38 and reaching a predetermined pressure pushes up the discharge valve 127 that closes the discharge port from the lower part of FIG. 1, opens the discharge port, and discharges it to the discharge muffling chamber 62. When it is time to finish discharging the refrigerant gas, the discharge valve 127 closes the discharge port.

On the other hand, in the lower support member 56, a part of the surface (lower surface) opposite to the surface in contact with the lower cylinder 40 is recessed, and the discharge sound deadening formed by closing the recessed portion with the lower cover 68. Room 64 is provided. The same discharge valve as in the case of the discharge muffling chamber 62 is also provided on the upper surface of the discharge muffling chamber 64, and the discharge port of the lower cylinder 40 is closed so as to be openable and closable. Then, the refrigerant gas compressed in the lower cylinder 40 and reaching a predetermined pressure pushes down the discharge valve closing the discharge port from above in FIG. 1 to open the discharge port and discharges it to the discharge muffling chamber 64. When it is time to finish discharging the refrigerant gas, the discharge valve closes the discharge port.

The discharge muffling chamber 64 of the first rotational compression element 32 and the inside of the closed container 12 are illustrated so as to penetrate the lower support member 56, the lower cylinder 40, the intermediate partition plate 36, the upper cylinder 38, the upper support member 54, and the upper cover 66. The intermediate pressure refrigerant gas compressed by the first rotational compression element 32 and discharged to the discharge muffling chamber 64 is communicated through the holes that do not exist, and the space inside the closed container 12 (electric element 14 and rotational compression mechanism). It is discharged to the space inside the closed container 12 other than the part 18.

Further, on the side surface of the container body 12A of the closed container 12, the upper support member 54, the suction passage 162 of the lower support member 54 (only the lower support member is shown), the side opposite to the suction passage of the upper support member 54, and the rotor 24. Sleeves 141, 142, 143 and 144 are welded and fixed at positions corresponding to the lower side (directly below the electric element 14), respectively. The sleeves 141 and 142 are slightly offset from each other to the left and right and are adjacent to each other at the top and bottom, and the sleeve 143 is substantially diagonal to the sleeve 141.

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

Further, one end of the refrigerant introduction pipe 94 for introducing the refrigerant gas into the lower cylinder 40 is inserted and connected into the sleeve 142, and one end of the refrigerant introduction pipe 94 communicates with the suction passage 162 of the lower cylinder 40. The path from the refrigerant introduction pipe 94 to the suction port 161 via the suction passage 162 is the refrigerant suction side of the first rotational compression element 32. Further, a refrigerant discharge pipe 96 is inserted and connected in the sleeve 143, and one end of the refrigerant introduction pipe 96 communicates with the discharge muffling chamber 62.

Next, the communication passage 101 and the valve device 102 of the present invention will be described with reference to FIG. A valve storage chamber 103 is formed in the lower cylinder 40 at a position corresponding to the lower side of the back pressure chamber 70A of the upper cylinder 38, and the inner end of the valve storage chamber 103 is closed in front of the suction port 161 and is outside. The end is open in the closed container 12. And this<u style="single">Valve storage room 103</u>The valve device 102 is movably housed inside (movable in the radial direction of the lower cylinder 40), and one surface (outer surface) of the valve device 102 facing the inside of the closed container 12 and the closed container 12 A spring member 104 (weak spring) is interposed between the container body 12A. The spring member 104 is always urged by a relatively weak force so that the valve device 102 moves toward the back of the valve storage chamber 103 (inward direction of the lower cylinder 40). The intermediate pressure in the closed container 12 and the urging force of the spring member 104 are applied to the surface of the valve.

A first communication hole 106 that penetrates to the lower surface of the lower cylinder 40 is formed on the bottom surface of the valve storage chamber 103, and a communication groove 107 is formed on the upper surface of the lower support member 56 at a position corresponding to the communication hole 106. It is formed. The communication groove 107 communicates the lower end opening of the communication hole 106 with the suction passage 162 (the refrigerant suction side of the first rotational compression element 32). Further, the upper end opening of the communication hole 106 is configured to be opened and closed by the valve device 102 by moving the valve device 102. Then, the communication passage 101 is formed by the valve storage chamber 103, the communication hole 106, and the communication groove 107.

On the other hand, a second communication hole 108 is formed through the intermediate partition plate 36 at a position corresponding to the back pressure chamber 70A of the upper cylinder 38, and further, a lower cylinder at a position corresponding to the lower end opening of the communication hole 108. A third communication hole 109 is formed in 40, and reaches the inner end portion in the valve storage chamber 103. Through these communication holes 108 and 109, the inside of the back pressure chamber 70A is communicated with the inner end of the valve storage chamber 103, and the high pressure which is the discharge side pressure of the second rotational compression element 34 applied to the back pressure chamber 70A is the valve. It will be applied to the other surface (inner surface) of the device 102.

Then, when the intermediate pressure in the closed container 12 (the discharge pressure of the first rotary compression element 32) reaches a predetermined upper limit value, the valve device 102 is, for example, the discharge pressure of the second rotary compression element 34. It is configured to open the communication passage 100 when the pressure becomes higher than the high pressure or when the pressure becomes a predetermined pressure before reaching the high pressure. Specifically, in the valve device 102 of this embodiment, the pressure in the closed container 12 (intermediate pressure PM which is the discharge pressure of the first rotational compression element 32) applied to one surface (spring member 104 side) is determined. The pressure (high pressure PH) in the discharge muffling chamber 62 of the second rotational compression element 34, which is the pressure in the back pressure chamber 70A (back pressure of the upper vane 50) applied to the other surface (back surface). If becomes, the communication passage 101 shall be opened.

That is, when the intermediate pressure PM in the closed container 12 applied to one surface (spring member 104 side) becomes equal to or higher than the high pressure PH in the back pressure chamber 70A applied to the other surface (back side), the sealing is performed. The pressure inside the container 12 pushes the valve device 102 inward (inward), and the outer end of the valve device 102 moves to the inner side of the valve storage chamber 103 from the upper end opening of the communication hole 106 (FIG. 3). .. As a result, the space inside the closed container 12 and the suction passage 162 are communicated with each other through the communication passage 101 (valve storage chamber 103, communication hole 106, communication groove 107), and the intermediate pressure refrigerant gas in the closed container 12 is released. It will flow into the suction passage 162 (refrigerant suction side) of the rotational compression element 32 of 1.

In this way, the intermediate pressure PM (discharge pressure of the first rotational compression element 32) in the closed container 12 applied to one surface (spring member 104 side) is applied to the other surface (back side). When the pressure becomes higher than the high pressure PH in the back pressure chamber 70A (the pressure in the discharge muffling chamber 62 of the second rotational compression element 34), it is compressed by the first rotational compression element 32 by opening the communication passage 101. , The intermediate pressure refrigerant gas discharged into the closed container 12 can be released from the suction passage 162 of the lower cylinder 40 of the first rotary compression element 32 to the suction port 161.

Here, the upper vane 50 and the lower vane (not shown) of the upper and lower cylinders 38 and 40 are arranged so that the upper vane 50 is shifted to the left side and the lower vane is shifted to the right side when viewed from above. Further, the discharge port and the suction port are formed adjacent to each side of these vanes, but in the present invention, the suction port is formed on the right side of the vane 50 and the discharge port is formed on the left side of the upper cylinder 38 when viewed from above. In the lower cylinder 40, a suction port 161 is formed on the left side of the lower vane and a discharge port is formed on the right side when viewed from above.

The back pressure chamber 70A of the upper cylinder 38, the valve storage chamber 103 of the lower cylinder 40, and the suction passage 162 of the lower support member 56 are arranged so as to be arranged vertically (in the axial direction of the rotating shaft 16) (FIG. 2). Then, since the valve storage chamber 103 is communicated with the suction passage 162 by the communication hole 106 and the communication groove 107 as the refrigerant suction side of the first rotational compression element 32, the communication holes 108, 109, 106 and the communication groove 107 are formed. The back pressure chamber 70A and the valve storage chamber 103, and the valve storage chamber 103 and the suction passage 162 can be communicated with each other in the shortest distance. Further, since the communication passage 101 is formed by opening the outer end of the valve storage chamber 103 into the closed container 12, the communication passage 101 in the rotation compression mechanism portion 18 and the back pressure chamber 70A are formed by these. The structure for communicating with the valve storage chamber 103 is extremely simplified. Therefore, the production cost for adopting a structure in which the pressure (intermediate pressure) on the first rotational compression element 32 refrigerant discharge side is released to the refrigerant suction side (low pressure) can be minimized.

Next, the operation of the rotary compressor 10 will be described with the above configuration. When the stator coil 28 of the electric element 14 is energized via the terminal 20 and wiring (not shown), the electric element 14 is activated and the rotor 24 is rotated. By this rotation, the vertical rollers 46, 48 are fitted into the vertical eccentric portions 42, 44 provided integrally with the rotating shaft 16, and the vertical rollers 46, 48 rotate eccentrically in the vertical cylinders 38, 40.

As a result, the low-pressure refrigerant sucked into the low-pressure chamber of the lower cylinder 40 from the suction port 161 via the refrigerant introduction pipe 94 and the suction passage 162 is compressed by the operation of the lower roller 48 and the lower vane, and reaches the intermediate pressure. Then, the discharge valve that closes the discharge port is pushed to open the discharge port, and the refrigerant gas having this intermediate pressure is discharged into the discharge muffling chamber 64.

The intermediate-pressure refrigerant gas discharged into the discharge muffling chamber 64 is discharged from the discharge muffling chamber 64 into the closed container 12 through a hole (not shown). As a result, the inside of the closed container 12 becomes the intermediate pressure (PM) which is the refrigerant discharge side pressure of the first rotational compression element 32. At this time, if the intermediate pressure PM of the closed container 12 is lower than the high-pressure PH that is compressed by the second rotational compression element 34 and supplied to the back pressure chamber 70A via the discharge muffling chamber 62, it is shown in FIG. As described above, the valve device 102 is pushed by the high pressure of the refrigerant in the back pressure chamber 70A and is located on the communication hole 106. Therefore, since the upper end opening of the communication hole 106 is closed by the valve device 102 and the communication passage 101 is closed, the refrigerant gas in the closed container 12 does not flow into the suction passage 162.

The intermediate-pressure refrigerant gas discharged into the closed container 12 exits from the sleeve 144 and passes from the suction port to the low-pressure chamber of the upper cylinder 38 via a suction passage (not shown) formed in the refrigerant introduction pipe 92 and the cylinder 38. Inhaled. The sucked intermediate pressure refrigerant gas is compressed in the second stage by the operation of the upper roller 46 and the upper vane 50 to become a high temperature and high pressure refrigerant gas. As a result, the discharge valve 127 provided in the discharge muffling chamber 62 is opened, and the discharge muffling chamber 62 and the discharge port communicate with each other. Therefore, the high pressure chamber of the upper cylinder 38 passes through the discharge port and is formed on the upper support member 54. Discharge to the muffling chamber 62. The high-pressure refrigerant gas discharged to the discharge muffling chamber 62 is discharged to the outside of the rotary compressor 10 via the refrigerant discharge pipe 96.

On the other hand, when the pressure of the refrigerant discharged into the closed container 12 (intermediate pressure PM) becomes higher than the high-pressure PH supplied into the storage chamber 70A via the discharge muffling chamber 62 after being compressed by the second rotational compression element 34. As shown in FIG. 3, the valve device 102 is pushed in by the pressure in the closed container 12 applied to one surface, and its outer end moves from the communication hole 106 to the inside (back side) of the valve storage chamber 103. .. As a result, the upper end opening of the communication hole 106 is opened, so that the communication passage 101 is opened, and the inside of the closed container 12 and the suction passage 162 are communicated with each other. As a result, the refrigerant gas in the closed container 12 flows into the suction passage 162 (refrigerant suction side) of the lower cylinder 40 through the valve storage chamber 103, the communication hole 106, and the communication groove 107. That is, a part of the intermediate pressure refrigerant gas compressed by the first rotary compression element 32 and discharged into the closed container 12 is sucked into the lower cylinder 40 through the suction passage 162 of the first rotary compression element 32. Can escape to the area of.

As a result, the intermediate-pressure refrigerant gas that is compressed by the first rotational compression element 32 and sucked into the second rotational compression element 34 is discharged to the discharge muffling chamber 62 of the second rotational compression element 34 and back pressure. It becomes less than or equal to the pressure of the refrigerant gas supplied to the chamber 70A as the back pressure of the upper vane 50. Therefore, the pressure reversal between the inner end (inside the upper cylinder 38) and the outer end (back pressure) of the upper vane 50 is eliminated. When the pressure of the intermediate pressure refrigerant gas in the closed container 12 becomes lower than the pressure of the refrigerant gas in the back pressure chamber 70A, the valve device 102 moves outward as shown in FIG. 2, and the upper end opening of the communication hole 106 is opened. Therefore, the communication passage 101 is blocked.

As described above, when the pressure of the refrigerant discharged into the closed container 12 becomes higher than the high pressure supplied to the back pressure chamber 70A via the discharge muffling chamber 62 after being compressed by the second rotational compression element 34, as described above. Since the communication passage 101 is opened and the refrigerant gas in the closed container 12 can be released to the suction passage 162 of the first rotary compression element 32, the pressure on the refrigerant discharge side of the first rotary compression element 32 (intermediate). Pressure PM) is lower than the pressure on the refrigerant discharge side of the second rotational compression element 34 (high pressure PH), and the pressure of the refrigerant gas compressed by the first rotational compression element 32 (pressure at the inner end of the upper vane 50). And the reversal of the pressure of the refrigerant gas compressed by the second rotational compression element 34 (the back pressure of the upper vane 50) can be eliminated.

As a result, the vane skipping and unstable operating conditions of the upper vane 50 of the second rotational compression element 34 can be eliminated at an early stage. In addition, since the complexity of the structure of the rotational compression mechanism portion 18 can be minimized, soaring production costs can be kept low. That is, the pressure reversal prevention structure can be simplified and the production cost can be reduced.

As described above, the inconvenience that the second rotary compression element 34 falls into an unstable operating condition can be eliminated, and stable operation of the multi-stage compression type rotary compressor 10 can be realized.

When the rotary compressor 10 is stopped, the valve device 102 is promptly pushed into the back side of the valve accommodating portion 103 by the spring member 104 as shown in FIG. 3, so that the communication passage 101 is opened. As a result, the pressure reversal of the entire refrigerant circuit is immediately restored after the rotary compressor 10 is stopped. Therefore, since the pressure reversal does not occur at the next start-up, it becomes possible to avoid the jump of the upper vane 50 from the beginning of the start-up.

Further, in the above-described embodiment, the spring member 104 of the valve device 102 is formed of a weak spring, and the pressure in the closed container 12 applied to one surface (spring member 104 side) is applied to the other surface (valve storage chamber). When the pressure in the back pressure chamber 70A (the pressure in the discharge muffling chamber 62 of the second rotational compression element 34) applied to (the back side of 103) is exceeded, the communication passage 101 is opened. Not limited to this, when the spring member 104 is composed of a normal spring and the pressure in the closed container 12 applied to one surface reaches a predetermined upper limit value, for example, it is applied to the other surface. When the pressure in the back pressure chamber 70A reaches a predetermined upper limit value set in advance (for example, the pressure immediately before reaching the high pressure PH), the communication passage 101 may be communicated.

In that case, the pressure of the refrigerant gas in the closed container 12 can always be lower than the pressure of the refrigerant gas supplied to the back pressure chamber 70A via the discharge muffling chamber 64 of the second rotational compression element 34. Therefore, the back pressure of the upper vane 52 of the second rotational compression element 34 can be secured, that is, the pressure in the upper cylinder 38 can always be equal to or less than the pressure of the back pressure chamber 70A of the upper vane 52. The high pressure PH, which is the discharge side pressure of the second rotational compression element 34 applied to the pressure chamber 70A, and the urging force of the spring 74 avoid the inconvenience of vane jumping of the upper vane 52, and the second rotation. A stable operating condition of the compression element 34 can be ensured.<u style="single">。</u>

Then refer to FIGS. 4-9.<u style="single">Reference example</u>Will be explained. In each figure, those shown by the same reference numerals as those in FIGS. 1 to 3 have the same functions, and the parts not shown in each figure are the same as those shown in FIGS. 1 to 3. FIG. 4 is a plan view of the rotary compression mechanism portion 18 in this case, FIG. 5 is an enlarged view of the valve storage chamber 103 portion of the rotary compression mechanism portion 18 of FIG. 4, and FIG. 6 is an enlarged vertical section of the valve storage chamber 103 portion of FIG. A side view, FIG. 7 is a sectional view taken along line AA in FIG. 4, FIG. 8 is a sectional view taken along line BB in FIG. 4, and FIG. 9 is a perspective view of the rotational compression mechanism portion 18 in FIG.

In each figure, 111 is a suction passage of a second rotational compression element 34 formed in the upper support member 54, which is<u style="single">Reference example</u>The upper and lower vanes are provided so as to correspond to the upper and lower vanes, and the suction port and the suction passages 111 and 162 are arranged side by side in the axial direction of the rotation shaft 16 on the right side when viewed from above.

In this case, the valve storage chamber 103 is formed in the upper support member 54 adjacent to the suction passage 111 side of the pressure passage 100, and the inner corner thereof communicates with the communication portion between the pressure passage 100 and the back pressure chamber 70A. doing. Similarly, the valve device 102 is movably housed in the valve storage chamber 103 (movable in the radial direction of the upper support member 54). Similarly, the outer end of the valve storage chamber 103 opens into the space inside the closed container 12, and the valve seat 112 is attached to the inside of the outer end opening. Further, the spring member 104 is interposed between the valve seat 112 and one surface of the valve device 102 (the surface on the valve seat 112 side). The spring member 104 always urges the valve device 102 to the rear side, that is, away from the valve seat 112.

With such a configuration, the pressure in the closed container 12 (intermediate pressure PM) is applied to one surface of the valve device 102, and the pressure in the back pressure chamber 70A is applied to the other surface (the surface on the pressure passage 100 side). (High pressure PH) will be applied.

Further, communication holes 113 are formed vertically in the upper support member 54, and the upper end of the communication holes 113 opens in the valve storage chamber 103 near the valve seat 112. Further, the upper cylinder 38, the intermediate partition plate 36, and the lower cylinder 40 are each formed with communication holes 114, 116, and 117 penetrating vertically, and the upper end of the communication hole 114 corresponds to the lower end of the communication hole 113. The upper end of the communication hole 116 communicates with the lower end of the communication hole 114, and the upper end of the communication hole 117 communicates with the lower end of the communication hole 116. A communication hole 118 is also formed in the vicinity of the suction passage 162 (lower vane side) of the lower support member 56, the lower end thereof communicates with the suction passage 162, and the upper end communicates with the lower end of the communication hole 117. There is. The valve storage chamber 103 and the communication holes 113, 114, 116, 117, 118 constitute the communication passage 101 in this case.

With the above configuration, when the intermediate pressure PM of the closed container 12 is lower than the high pressure PH supplied to the back pressure chamber 70A via the discharge muffling chamber 62 and the pressure passage 100 after being compressed by the second rotational compression element 34. As shown in FIGS. 6 and 7, the valve device 102 is pushed by the high pressure of the refrigerant in the back pressure chamber 70A and pressed against the valve seat 112 to close the upper end opening of the communication passage 113. Therefore, since the communication passage 101 is in a closed state, the refrigerant gas in the closed container 12 does not flow into the suction passage 162.

On the other hand, the pressure of the refrigerant discharged into the closed container 12 (intermediate pressure PM) is compressed by the second rotational compression element 34, and is supplied into the storage chamber 70A via the discharge muffling chamber 62 and the pressure passage 100. When the pH is equal to or higher than PH, the valve device 102 is separated from the valve seat 112 by the pressure in the closed container 12 applied to one surface and pushed into the inner side (pressure passage 100 side), and the outer end thereof is the communication hole 113. Move to the inside (back side) of the valve storage chamber 103 from the upper end opening. As a result, the upper end opening of the communication hole 113 is opened, so that the communication passage 101 is opened, and the inside of the closed container 12 and the suction passage 162 are communicated with each other. As a result, the refrigerant gas in the closed container 12 flows into the suction passage 162 (refrigerant suction side) of the lower cylinder 40 through the valve storage chamber 103 and the communication holes 113, 114, 116, 117, 118. That is, a part of the intermediate pressure refrigerant gas compressed by the first rotary compression element 32 and discharged into the closed container 12 passes through the suction passage 162 of the first rotary compression element 32 and is sucked into the lower cylinder 40. Will escape to the realm of.

As a result, the pressure reversal phenomenon can be eliminated and the occurrence of jumping of the upper vane 50 can be avoided as in the above-described embodiment. In particular, in this case, the valve device 102 is not housed in the cylinder, but is housed in the upper support member 54, so that restrictions on machining accuracy are relaxed. Further, since the pressure can be applied to both sides of the valve device 102 at a position extremely close to both the back pressure chamber 70A and the inside of the closed container 12, there is an effect that the accuracy of the opening / closing control of the communication passage 101 is improved.

still,<u style="single">The above embodiment</u>Although the rotary compressor 10 has been described by using a two-stage compression type rotary compressor, the present invention may be applied to a rotary compressor having three or more stages of rotational compression elements.

<figref num="1">It is a longitudinal side view of the multistage compression type rotary compressor of one Example to which this invention was applied (Example 1).</figref><figref num="2">It is an enlarged longitudinal side view of the upper vane part of the 2nd rotary compression element of the multistage compression type rotary compressor of FIG.</figref><figref num="3">Similarly, it is an enlarged longitudinal side view of the upper vane portion of the second rotary compression element of the multi-stage compression type rotary compressor of FIG.</figref><figref num="4">It is a top view of the rotary compression mechanism part of the multistage compression type rotary compressor of another Example to which this invention was applied (<u style="single">Reference example</u>)。</figref><figref num="5">It is an enlarged view of the valve storage chamber part of the rotary compression mechanism part of FIG.</figref><figref num="6">It is an enlarged vertical side view of the valve storage chamber part of FIG.</figref><figref num="7">It is the AA line sectional view of FIG.</figref><figref num="8">It is the BB line sectional view of FIG.</figref><figref num="9">It is a perspective view of the rotation compression mechanism part of FIG.</figref>

10 Multi-stage compression type rotary compressor 12 Closed container 14 Electric element 16 axis of rotation 18 Rotational compression mechanism 32 First rotational compression element 34 Second rotational compression element 38 Upper cylinder 40 Lower cylinder 42, 44 eccentric part 46 Upper roller 48 Lower roller 50 upper vanes 62, 64 Discharge muffling chamber 70A back pressure chamber 100 pressure passage 101 consecutive passages 102 Valve gear 104 Spring member 106, 108, 109, 113, 114, 116, 117, 118 communication holes 107 Communication groove 162 Suction passage