Rotary compressor

Abstract

To suppress vane skip to improve operation efficiency of a rotary compressor by installing a pressure chamber that secures delivery of oil for lubrication to a vane slot and presses a vane on a roller side with a high pressure by sealing a vane back-side space.SOLUTION: A rotary compressor includes vane back pressure-side pressure chambers 54, 56 that are capable of forming vane back pressure that is higher than pressure of an internal space 3 of a closed vessel 2 and provided in vane back-side spaces 53, 55 of vanes 17, 23 of vane slots 39, 40 provided in cylinders 15, 21 of rotation pressure elements 4, 5.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a rotary compressor having an electric element and a rotary compression element in a sealed container.

Background Art

[0002] Conventionally, a rotary compressor used for applications such as connecting to a refrigeration cycle and circulating refrigerant in the refrigeration cycle is configured by housing an electric element and a rotary compression element in a sealed container. In particular, in the case of a vertical type, the electric element and the rotary compression element are arranged vertically inside a vertically long sealed container, and in the case of a horizontal type, the electric element and the rotary compression element are arranged side by side horizontally inside a horizontally long sealed container.

[0003] The electric element includes, for example, a stator (stator) annularly attached along the inner peripheral surface of the body of the sealed container as shown in Patent Document 1, and a rotor (rotor) fixed to a rotary shaft provided inside the stator so as to be rotatable by a magnetic field generated by the stator and having an eccentric portion (crankshaft) for driving the rotary compression element.

[0004] The rotary compression element includes a cylinder, a roller fitted to the eccentric portion of the rotary shaft and eccentrically rotating inside the cylinder, and a vane in sliding contact with the peripheral surface of the roller and partitioning the inside of the cylinder into a low-pressure chamber side and a high-pressure chamber side.

[0005] The bottom side in the sealed container is a region where oil accumulates, and the accumulated oil is mainly sent to the sliding contact portion using a rotary shaft or the like and provided for lubrication.

[0006] In the electric element, when the winding of the stator of the electric element is energized to generate a rotating magnetic field, the rotor provided inside the rotating magnetic field rotates. Due to the rotation of this rotor, the roller fitted to the eccentric portion of the rotary shaft eccentrically rotates inside the cylinder.

[0007] In the cylinder of the rotary compression element, a vane abuts against a roller, and the inside of the cylinder is partitioned into a low-pressure chamber and a high-pressure chamber. Due to the eccentric rotation of the roller, low-pressure refrigerant is inhaled from the refrigeration circuit side into the low-pressure chamber side inside the cylinder. After being compressed by the operation of the roller and the vane, the refrigerant is discharged into the high-pressure space.

[0008] In the rotary compressor, when sending out high-pressure refrigerant from inside the cylinder into the sealed container, it is passed through a discharge muffler. The refrigerant compressed to a high pressure inside the cylinder is discharged into the inside of the discharge muffler from the high-pressure chamber side through a discharge port.

[0009] The refrigerant discharged into the inside of the discharge muffler is discharged into the space inside the sealed container. And it is configured to be discharged from the refrigerant pipe to the outside, that is, to the refrigeration circuit.

[0010] In the rotary compression element of the rotary compressor with the above configuration, as described above, inside the cylinder, a vane that can move along the direction facing the rotation center of the roller abuts against the circumferential surface of the roller, and the inside of the cylinder is partitioned into a low-pressure chamber side and a high-pressure chamber side by this vane.

[0011] A vane slot for accommodating the vane is formed in the cylinder, and the vane slot accommodates the vane movably. And there is a part where a spring is arranged inside the vane slot. The differential pressure applied to this spring and the vane (the difference between the pressure inside the cylinder and the pressure of the internal space of the sealed container) always presses the vane toward the roller rotation center direction and makes it contact slidably with the circumferential surface of the eccentrically rotating roller.

[0012] As described above, the differential pressure applied to this spring and the vane (the difference between the pressure inside the cylinder and the pressure of the internal space of the sealed container) presses against the roller side to partition the inside of the cylinder into a low-pressure chamber side and a high-pressure chamber side. However, when the differential pressure applied to the vane is small and the inertial force when the vane moves to the top dead center side is large, a phenomenon occurs where the vane separates from the roller, which is a phenomenon called vane jump.

Prior Art Documents

Patent Document

[0013]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0014] In the above rotary compressor, as described above, the pressing force of the vane toward the roller side is mainly determined by the pressure difference applied to the vane (the difference between the high pressure behind the vane (vane back pressure) and the refrigerant pressure on the low-pressure space side in the cylinder and the refrigerant pressure on the high-pressure side space in the cylinder), the pressing force of the spring, the inertial force acting on the vane, and the like.

[0015] In a rotary compressor, when high-speed operation is performed when the pressure difference is low (at low differential pressure), the inertial force acting on the vane exceeds the resultant force of the pressure of the refrigerant pressing the vane from behind the vane toward the roller side and the pressing force of the spring, and a phenomenon of vane jumping occurs where the vane cannot be pressed against the roller. Also, when the reaction force against the moving direction of the vane, which is caused by the distortion of the vane slot and the roughness of the surface where the vane and the vane slot rub against each other, is high, the same phenomenon of vane jumping occurs.

[0016] If the pressing force of the vane is simply strengthened as a countermeasure against vane jumping, a method of increasing the pressing force of the spring can be considered. However, in this method, it is necessary to increase the wire diameter of the spring or change the material of the spring. Therefore, there may be cases where the spring cannot be housed inside the vane slot dimensionally. Furthermore, since the spring may be subject to fatigue failure due to excessive stress, it is assumed that the long-term reliability of the rotary compressor may be impaired, or the pressing force during operation may increase more than necessary, increasing the sliding resistance of the vane and reducing the operating efficiency of the rotary compressor. Therefore, simply increasing the pressing force of the spring is not necessarily appropriate as a method of preventing vane jumping.

[0017] An object of the present invention is to provide a rotary compressor that can suppress vane flutter and prevent deterioration of the operating efficiency of the rotary compressor.

Means for Solving the Problems

[0018] The present invention includes an electric element and a rotary compression element driven by a rotary shaft of the electric element in a sealed container. The rotary compression element includes a cylinder, a roller disposed on an eccentric portion formed on the rotary shaft and eccentrically rotating inside the cylinder, a vane that moves from the top dead center to the dead center and abuts against the circumferential surface of the roller to partition the inside of the cylinder into a high-pressure chamber and a low-pressure chamber, a vane slot formed in the cylinder and accommodating the vane movably, and a spring provided in the vane slot and biasing the vane toward the bottom dead center. A vane back pressure side pressure chamber capable of forming a vane back pressure higher than the pressure of the space in the sealed container is provided in a vane back space on the side of the vane slot opposite to the roller. A passage hole communicating with the space in the sealed container is opened on a sliding contact surface with the vane in the vane back pressure side pressure chamber. The rotary compressor is characterized in that at least a part of the passage hole is closed by the vane pushed up by the roller.

[0019] Further, in the present invention, the vane moves in the vane slot within a range from the top dead center to the bottom dead center as the roller eccentrically rotates. The passage hole is provided at a position where it is in an open state when the vane is near the bottom dead center.

[0020] Further, in the present invention, when the passage hole is opened, it communicates with the space in the sealed container, and the vane back pressure in the vane back pressure side pressure chamber is the same as the pressure of the space in the sealed container.

[0021] Further, in the present invention, two rotary compression elements are provided side by side in the sealed container with the plate middle therebetween. The plate middle is provided with communication passages that connect from the portion on the rotating shaft side to the vane back pressure side pressure chambers of the two rotary compression elements respectively. The communication passages are characterized in that the portion on the space side in the sealed container is open, and the pass holes are provided at positions corresponding to the vane back pressure side pressure chambers in the two rotary compression elements respectively.

Advantages of the Invention

[0022] According to the present invention, a vane back pressure side pressure chamber capable of forming a vane back pressure higher than the pressure of the space in the sealed container is provided in the vane back space on the side opposite to the roller of the vane in the vane slot. Since the vane back pressure in the vane back pressure side pressure chamber is higher than the pressure of the high-pressure refrigerant in the space in the sealed container, the vane can be properly pressed against the roller by the combined force of the pressing force of the spring and the vane back pressure. Thereby, vane flutter can be suppressed, and it is possible to prevent an excessive pressing force from acting on the vane and impairing the operating efficiency of the rotary compressor.

[0023] Also, a pass hole communicating with the space in the sealed container opens on the sliding contact surface with the vane in the vane back pressure side pressure chamber, and at least a part of the pass hole is closed by the vane pushed up by the roller, so that the vane back pressure side pressure chamber can be substantially sealed, and the volume of the vane back pressure side pressure chamber can be reduced by the vane pushed up.

[0024] Therefore, the vane back pressure by the refrigerant confined in the vane back pressure side pressure chamber can be increased by a simple mechanism. And the pass hole can also be used for feeding lubricating oil in the sealed container.

[0025] Also, according to the present invention, as the roller eccentrically rotates, the vane moves within the vane slot in the range from the top dead center to the bottom dead center, and the passage hole is provided at a position where it is in an open state when the vane is near the bottom dead center. Therefore, when the vane is near the bottom dead center, the pressure in the pressure chamber on the back pressure side of the vane can be made the same as the pressure in the space within the sealed container.

[0026] Also, according to the present invention, when the passage hole is open, by making the vane back pressure in the vane back pressure side pressure chamber the same as the pressure in the space within the sealed container, it is possible to prevent the load pressing the vane against the roller from becoming excessive, which would otherwise increase the sliding resistance and reduce the operating efficiency of the rotary compressor.

[0027] Also, according to the present invention, two rotary compression elements are provided side by side within the sealed container with the plate middle in between. And the plate middle is provided with a communication passage that connects the vane back pressure side pressure chambers of the two rotary compression elements respectively with the space within the sealed container to allow refrigerant to pass through to the vane back pressure side pressure chambers.

[0028] The communication passage has a portion on the space side within the sealed container that is open, and the passage hole is provided at a position corresponding to the vane back pressure side pressure chamber in each of the two rotary compression elements.

[0029] Since the plate middle is positioned between the two rotary compression elements arranged in this way, and the communication passage provided in the plate middle is provided with passage holes corresponding to the vane back pressure side pressure chambers respectively, it is possible to easily form vane back pressure side pressure chambers in each of the two rotary compression elements.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

DETAILED DESCRIPTION OF THE INVENTION

[0031] Next, the present invention will be described in detail based on the illustrated embodiments. Reference numeral 1 indicates a rotary compressor of the present invention, and a rotary compression mechanism portion 6 in which a first rotary compression element 4 and a second rotary compression element 5 are vertically overlapped is accommodated in the lower part of the internal space 3 of a sealed container 2. Also, it is a two-cylinder sealed rotary compressor that accommodates an electric element 7 above the rotary compression mechanism portion 6.

[0032] (Sealed Container) The sealed container 2 is composed of a container body 8 that arranges the electric element 7 and the first and second rotary compression elements 4 and 5 inside, a bowl-shaped end cap 9 that closes the upper opening which is one opening portion of the container body 8, and a bowl-shaped bottom 10 that closes the lower opening of the container body 8.

[0033] On the upper surface of the end cap 9 at the upper part of the sealed container 2, a circular mounting hole is formed, and a terminal 11 for supplying power to the electric element 7 located above in the sealed container 2 is attached to this mounting hole. Further, a refrigerant discharge pipe 12 is attached near the center of the end cap 9.

[0034] The bottom side of the internal space 3 of the sealed container 2 is an oil reservoir area, and oil (not shown) for lubricating the sliding contact parts such as the first rotary compression element 4 and the second rotary compression element 5 is stored. An attachment base 13 is provided outside the bottom 10.

[0035] The rotary compression mechanism part 6 is composed of a first rotary compression element 4, a second rotary compression element 5, and a plate middle 14 sandwiched between the first and second rotary compression elements 4 and 5. And in the rotary compression mechanism part 6, the first rotary compression element 4 is arranged on the upper side (end cap 9 side) of the plate middle 14, and the second rotary compression element 5 is arranged on the lower side (bottom 10 side).

[0036] (First rotary compression element) The first rotary compression element 4 includes a cylinder 15 arranged on the plate middle 14, a roller 16 arranged in the cylinder 15 and eccentrically rotating inside the cylinder 15, a vane 17 that slidably contacts the outer peripheral surface of the roller 16 and partitions the inside of the cylinder 15 into a low-pressure chamber side and a high-pressure chamber side, and an upper support member 20 that closes the upper opening surface of the cylinder 15 and has a main bearing portion 19 for bearing the rotary shaft 18 extending from the electric element 7 side.

[0037] (Second rotary compression element) Also, the second rotary compression element 5 includes a cylinder 21 arranged under the plate middle 14, a roller 22 arranged in the cylinder 21 and eccentrically rotating inside the cylinder 21, a vane 23 that slidably contacts the outer peripheral surface of the roller 22 and partitions the inside of the cylinder 21 into a low-pressure chamber side and a high-pressure chamber side, and a lower support member 25 that closes the lower opening surface of the cylinder 21 and has a sub-bearing portion 24 of the rotary shaft 18 from the electric element 7 side.

[0038] The roller 16 disposed in the cylinder 15 of the first rotary compression element 4 and the roller 22 disposed in the cylinder 21 of the second rotary compression element 5 are disposed on the eccentric portions 26, 27 provided on the rotary shaft 18. The roller 16 and the roller 22 rotate eccentrically with a phase difference of 180 degrees.

[0039] FIG. 2 shows a state of the rotary compression mechanism portion 6 as viewed from above. As shown in FIG. 2, suction passages 28, 29 communicating with the inside of the cylinders 15, 21 are formed in the cylinder 15 of the first rotary compression element 4 and the cylinder 21 of the second rotary compression element 5. The suction passages 28, 29 are passages through which the refrigerant enters the cylinders 15, 21 from the refrigeration cycle side in which the rotary compressor 1 is incorporated.

[0040] (Discharge muffler) As shown in FIG. 1, in the rotary compression mechanism portion 6, discharge mufflers 30, 31 are provided on the side of the electric element 7 of the upper support member 20 and the side of the bottom 10 of the lower support member 25, respectively.

[0041] Then, the refrigerant compressed by the second rotary compression element 5 is sent into the discharge muffler 31 and finally sent into the internal space 3 in the sealed container 2. The refrigerant compressed by the first rotary compression element 4 is sent into the discharge muffler 30 and discharged into the internal space 3 of the sealed container 2.

[0042] (Electric element) The electric element 7 is located in the internal space 3 of the region surrounded by the portion of the container body 8 of the sealed container 2, and includes a stator 32 welded and fixed annularly along the inner peripheral surface of the container body 8, and a rotor 33 rotatably inserted inside the stator 32 by the magnetic field of the stator 32.

[0043] The stator 32 is composed of, for example, a stator iron core 34 formed by laminating annular iron plates for the stator, and a stator coil 35 wound around the stator iron core 34. Further, on the outer surface of the stator iron core 34, a plurality of longitudinal grooves 36 are formed in the axial direction along the inner peripheral surface of the container body 8.

[0044] The rotor 33 is composed of a rotor iron core 37 made of an electromagnetic steel sheet with permanent magnets embedded therein, and a rotating shaft 18 inserted and fixed in the central hole of the rotor iron core 37. The rotating shaft 18 extends so as to pass through the rotary compression mechanism portion 6 as described above, and the eccentric portions 26, 27 formed corresponding to the portion of the rotary compression mechanism portion 6 rotate to drive the first rotary compression element 4 and the second rotary compression element 5.

[0045] The lower end of the rotating shaft 18 is located in the oil sump below the rotary compression mechanism portion 6 and is immersed in the oil stored in the oil sump. And, an oil supply mechanism (not shown) is incorporated at the lower end of the rotating shaft 18, and oil is provided to be fed to the sliding contact portions such as the eccentric portions 26, 27 and the rollers 16, 22 as the rotating shaft 18 rotates.

[0046] Also, the oil from the lower end of the rotating shaft 18 is also fed to the portion of the central opening through which the rotating shaft 18 passes in the plate middle 14. The plate middle 14 is provided with a communication passage 38 as shown in FIG. 1. The communication passage 38 is formed as a through portion that communicates from the side of the central opening corresponding to the rotating shaft 18 to the internal space 3 of the sealed container 2 on the outer peripheral side of the rotary compression mechanism portion 6.

[0047] The communication passage 38 is arranged at a position corresponding to the vane slot 39 provided in the first rotary compression element 4 and the vane slot 40 provided in the second rotary compression element 5. Further, in the communication passage 38, a passage hole 41 that opens facing the vane slot 39 side and a passage hole 42 that also opens facing the vane slot 40 side are formed.

[0048] In the present embodiment, a device is provided for increasing the vane back pressure, which will be described later, by utilizing the passage holes 41 and 42 that open into the communication passage 38.

[0049] (Accumulator) On the side surface of the container body 8 of the sealed container 2, sleeves are welded and fixed at positions corresponding to the suction passages 28 of the cylinder 15 and the suction passage 29 of the cylinder 21, respectively. A refrigerant introduction pipe 43 for introducing refrigerant into the cylinder 15 is attached to one of the sleeves on the end cap 9 side and communicates with the suction passage 28. The other end of the refrigerant introduction pipe 43 opens at the upper part inside the accumulator 44.

[0050] A refrigerant introduction pipe 45 for introducing refrigerant into the cylinder 21 is attached to the other sleeve located on the bottom 10 side and communicates with the suction passage 29. Similar to the case of the refrigerant introduction pipe 43, the other end of the refrigerant introduction pipe 45 opens at the upper part inside the accumulator 44.

[0051] In FIG. 1, in order to make the explanation of the cross-sectional portions of the vane slots 39 of the first rotary compression element 4 and the vane slots 40 of the second rotary compression element 5 easier to understand, an elevation view is shown in which the cross-sectional portions of the vane slots 39 and 40 and the refrigerant introduction pipes 43 and 45 are arranged side by side.

[0052] The accumulator 44 is a part for performing gas-liquid separation of the suction refrigerant. It is attached to the side of the container body 8 of the sealed container 2. One end of a refrigerant pipe 46 is connected to the upper end of the accumulator 44.

[0053] (Vane) In FIG. 2, the rotary compression mechanism part 6 is viewed from above, and the first rotary compression element 4, the plate middle 14, and the second rotary compression element 5 are shown in a state where they overlap. In FIG. 2, the portions indicated by reference numerals 47 and 48 show notches for sending the refrigerant at high pressure from the cylinders 15 and 21 to the discharge passage.

[0054] The vane 17 of the upper first rotary compression element 4 is slidably abutted against the circumferential surface of the roller 16 that eccentrically rotates as described above, and divides the inside of the cylinder 15 into a low-pressure chamber side and a high-pressure chamber side. And the vane 17 is movably accommodated in the vane slot 39 formed in the cylinder 15.

[0055] The vane 23 of the second rotary compression element 5 located on the lower side also slidably abuts against the circumferential surface of the roller 22 that eccentrically rotates as described above, and divides the inside of the cylinder 21 into a low-pressure chamber side and a high-pressure chamber side. And the vane 23 is movably accommodated in the vane slot 40 formed in the cylinder 21.

[0056] In FIG. 2 when looking at the rotary compression mechanism portion 6 from above, the first rotary compression element 4 is shown in the front position in the drawing, and the second rotary compression element 5 on the bottom 10 side is represented as the rear position in the drawing. The rotational position of the roller 16 when pushing the vane 17 of the first rotary compression element 4 to the top dead center is set to 0 degrees with the crank angle. The state of the first rotary compression element 4 in FIG. 2 indicates that the roller 16 is at the position of 180 degrees with the crank angle and the vane 17 is at the bottom dead center.

[0057] Also, the roller 22 of the second rotary compression element 5 eccentrically rotates with a 180-degree phase difference from the roller 16 of the first rotary compression element 4. And the state shown in FIG. 2 indicates that the vane 23 pushed up by the roller 22 is at the top dead center position.

[0058] Here, the position where the vanes 17 and 23 protrude the most from the vane slots 39 and 40 is called the bottom dead center, and the position where they are most accommodated in the vane slots 39 and 40 is called the top dead center. The vanes 17 and 23 move from the top dead center to the bottom dead center. At this time, the movement of the vanes 17 and 23 is in the direction along the direction facing the rotational centers of the rollers 116 and 22.

[0059] FIG. 3 shows a half-section of the rotary compression mechanism section 6, representing one side thereof, and shows the vanes 17, 23 and the vane back-pressure side compression chambers 54, 56 of the first rotary compression element 4 and the second rotary compression element 5 respectively. Springs 49, 50 are inserted into the vane slots 39, 40 that movably house the vanes 17, 23 from the side opposite to the protruding ends of the vanes 17, 23 as shown in FIG. 3, and plugs 51, 52 are fitted as sealing members from the outer side to seal the portions of the base slots 39, 40 on the container body 8 side. In the present embodiment, the plugs 51, 52 are lid-shaped members, but they may be formed with plug holes which are through holes for discharging oil or the like.

[0060] The vanes 17, 23 are biased toward the rollers 16, 22 by the springs 49, 50 on the back side of the vanes opposite to the vane protruding ends and abut against the rollers 16, 22. Further, in the present embodiment, a measure is taken to prevent the vanes from jumping.

[0061] (Vane back-pressure side pressure chamber) As shown in FIG. 3, vane back-pressure side pressure chambers 54, 56 are provided in the vane back spaces 53, 55 on the side opposite to the roller 16, 22 side of the vanes 17, 23 in the vane slots 39 of the first rotary compression element 4 and the vane slots 40 of the second rotary compression element 5 respectively.

[0062] The refrigerant in the internal space of the sealed container 2 is the refrigerant discharged from the first and second rotary compression elements 4, 5, so the pressure in the internal space of the sealed container 2 is high pressure. The vane back-pressure side pressure chambers 54, 56 are portions that can form a vane back-pressure higher than the pressure of the refrigerant in the internal space 3 of the sealed container 2, and at a predetermined timing, a vane back-pressure higher than the pressure of the refrigerant in the internal space 3 is applied to the vanes 17, 23 to suppress vane jumping.

[0063] As shown in Fig. 3, a plate middle 14 is disposed between vane back-pressure side pressure chambers 54 and 56, and a passage hole 41 corresponding to a vane slot 39 and a passage hole 42 corresponding to a vane slot 40 are opened in a communication passage 38 that penetrates the plate middle 14 from the side of the rotating shaft 18 toward the container body 8. Further, oil for lubricating the sliding contact portions in the vane slots 39 and 40 can be fed into the vane slots 39 and 40 through the passage holes 41 and 42 via the communication passage 38 from the side of the rotating shaft 18.

[0064] Furthermore, the passage holes 41 and 42 are formed at positions that are sliding contact surfaces with the vanes 17 and 23 in the vane back-pressure side pressure chambers 54 and 56, and can be opened and closed by the movement of the vanes 17 and 23. Therefore, when the passage holes 41 and 42 are closed by the vanes 17 and 23 pushed up by the rollers 16 and 22, the vane back-pressure side pressure chambers 54 and 56 are sealed.

[0065] Then, with the passage holes 41 and 42 remaining closed, the volume of the vane back-pressure side pressure chambers 54 and 56 becomes smaller because the portions on the back side (the upper side in Fig. 3) of the vanes 17 and 23 are located on the side of the plugs 51 and 52 (the container body 8 side of the sealed container 2).

[0066] When the passage holes 41 and 42 are open, the high-pressure refrigerant in the internal space 3 of the sealed container 2 fills the vane back-pressure side pressure chambers 54 and 56 through the communication passage 38 and the passage holes 41 and 42, and the pressure in the internal space 3 of the sealed container 2 is in the same state.

[0067] However, as described above, since the vane back-pressure side pressure chambers 54 and 56 are sealed and the volume becomes smaller, the vane back-pressure in the vane back-pressure side pressure chambers 54 and 56 rises above the pressure in the internal space 3 of the sealed container 2.

[0068] When the passage holes 41 and 42 are open, the vane back-pressure chambers 54 and 56 apply a vane back-pressure equal to the pressure in the internal space 3 of the sealed container 2 to the vanes 17 and 23, acting in a direction to press the vanes 17 and 23 against the rollers 16 and 22. When the passage holes 41 and 42 are closed, a vane back-pressure higher than the pressure in the internal space 3 of the sealed container 2 as described above is applied to the vanes 17 and 23, acting to press the vanes 17 and 23 more strongly against the rollers 16 and 22.

[0069] Of course, the force pressing the vanes 17 and 23 is a combination of the pressing forces of the springs 49 and 50 and the vane back-pressure, whether the passage holes 41 and 42 are open or closed.

[0070] FIG. 4 is a graph schematically showing the change in the vane back-pressure in the vane back-pressure chamber 54 of the first rotary compression element 4 on the end cap 9 side. FIG. 4 shows, in a graph, the change in the vane back-pressure in the vane back-pressure chamber 54 when there is a communication passage 38 communicating with the internal space 3 of the sealed container 2. Note that FIG. 4 shows the change in the vane back-pressure when the rotary compressor 1 is continuously operating, not at the start-up time.

[0071] In FIG. 4, the horizontal axis represents the crank angle (deg), which is the position of the roller 16 of the first rotary compression element 4. The starting point of the horizontal axis is when the crank angle is 0 degrees and the vane 17 is arranged at the top dead center position by the roller 16.

[0072] Although not shown in the graph of FIG. 4, since the roller 22 of the second rotary compression element 5 eccentrically rotates with a phase difference of 180 degrees with respect to the roller 16, the change in the vane back-pressure in the vane back-pressure compression chamber 56 of the second rotary compression element 5 is shifted by 180 degrees of the crank angle.

[0073] As shown in FIG. 4, in the vane back-pressure side compression chamber 54, until the vane 17 moves toward the roller rotation center side (downward in FIG. 3) from the state of the crank angle being 0 degrees and the passage hole 41 is opened, the vane back space 54 expands, so although the vane back pressure gradually decreases, the vane back pressure is in a state of being boosted from the pressure of the refrigerant in the internal space 3 of the sealed container 2, and a state is shown in which the vane 17 is pressed against the roller 16 side.

[0074] Next, when the roller 16 is rotating at the position of the crank angle that opens the passage hole 41, as described above, refrigerant enters the vane back space 54 through the open portion on the sealed container 2 side of the communication passage 38 and the passage hole 41, and the vane back pressure becomes the same as the pressure of the refrigerant in the internal space 3 of the sealed container 2.

[0075] Next, when the roller 16 advances to the position of the crank angle that pushes up the vane 17 and the vane 17 closes the passage hole 41, the vane back-pressure side compression chamber 54 is sealed. And in FIG. 4, as the position of the roller 16 advances toward 360 degrees at the crank angle, the volume of the vane back space 54 of the vane 17 becomes smaller, so the vane back pressure is boosted from the pressure of the refrigerant in the internal space 3 of the sealed container 2, and a state is shown in which the vane 17 receives a vane back pressure higher than the pressure of the refrigerant in the internal space 3 and is pressed against the roller 16 side.

[0076] FIG. 5 shows, in a graph, the change in the vane back pressure in the vane back-pressure side compression chamber 54 in the first rotary compression element 4 when both ends of the communication passage 38 are hypothetically closed.

[0077] That is, even when the passage holes 41 and 42 are in an open state, a change is shown assuming a case where the vane back-pressure side compression chamber 54 of the first rotary compression element 4 and the vane back-pressure side pressure chamber 56 of the second rotary compression element 5 do not communicate with the internal space 3 of the sealed container 2.

[0078] It is shown that as the position of the roller 16 in the first rotary compression element 4 advances from the crank angle of 0 degrees, the vane back pressure in the vane back-pressure side compression chamber 54 decreases from the state where it is the same as the pressure in the internal space 3 of the sealed container 2.

[0079] Then, when the roller 16 advances to a position where the path hole 41 is opened by the movement of the vane 17 toward the roller rotation center side, the vane back pressure side pressure chamber 56 of the second rotary compression element 5 communicates with the vane rear space 55, and the vane back pressure drops.

[0080] Next, as the vane rear space 55 of the vane back pressure side pressure chamber 56 in the second rotary compression element 5 becomes smaller, the vane back pressure in the vane back pressure side pressure chamber 54 of the first rotary compression element 4 temporarily increases under the influence.

[0081] Then, as the position of the roller 16 in the first rotary compression element 4 (from around the crank angle of 120 degrees to around 240 degrees in FIG. 5) advances, it is shown that the vane back pressure changes in a state where the vane back pressure is lower than the pressure in the internal space 3 of the sealed container 2.

[0082] Furthermore, when the position of the roller 16 further advances, the path hole 42 on the second rotary compression element 5 side is opened again, the vane rear space 55 of the vane back pressure side pressure chamber 56 communicates with the vane back pressure side pressure chamber 54, and the vane back pressure drops again.

[0083] And it is shown that the vane back pressure in the vane back pressure side compression chamber 54 increases when the path hole 41 is closed. Since the vane back pressure side compression chamber 54 does not communicate with the internal space 3 of the sealed container 2, it is shown that it does not become higher than the pressure of the refrigerant in the internal space 3 of the sealed container 2. This point is the same as that of the vane back pressure side compression chamber 56.

[0084] As described above, the case where the container body 8 side of the sealed container 2 of the communication path 38 is opened (FIG. 4) and the case where it is not opened and the vane back pressure side compression chambers 54 and 56 do not communicate with the internal space 3 of the sealed container 2 (FIG. 5) are shown. By opening the container body 8 side of the sealed container 2 of the communication path 38 in this way so that the vane back pressure side compression chambers 54 and 56 can communicate with the internal space 3 of the sealed container 2, the vane back pressure can be made higher than the pressure in the internal space 3 of the sealed container 2.

[0085] Also, since the vane back-pressure side compression chambers 54 and 56 communicate with the internal space 3 of the sealed container 2 through the communication passage 38, when the refrigerant pressurized in the vane back-pressure side pressure chambers 54 and 56 passes through the pass holes 41 and 42, it can flow smoothly toward the internal space 3 of the sealed container 2 through the communication passage 38. Further, even if excessive oil comes as lubricating oil from the portion on the rotation shaft 18 side of the plate middle 14 toward the pass holes 41 and 42 side, it can still be guided to flow smoothly toward the internal space 3 of the sealed container 2, and it can be prevented from being excessively confined in the vane back-pressure side compression chambers 54 and 56.

[0086] In the rotary compressor mechanism portion 6 of the rotary compressor 1 of the embodiment, as described above, the first rotary compression element 4 located on the end cap 9 side and the second rotary compression element 5 located on the bottom 10 side are stacked vertically with the plate middle 14 sandwiched therebetween.

[0087] And since the roller 16 of the first rotary compression element 4 and the roller 22 of the second rotary compression element 5 eccentrically rotate with a phase difference of 180 degrees in the crank angle, the vane 17 of the first rotary compression element 4 and the vane 23 of the second rotary compression element 5 operate shifted by a phase difference of 180 degrees.

[0088] Therefore, the change in which the vane rear space 53 of the first rotary compression element 4 expands and contracts and the change in which the vane rear space 55 of the second rotary compression element 5 expands and contracts are shifted by a phase difference of 180 degrees.

[0089] FIG. 6 shows the rotary compressor mechanism portion 6 cut in half and representing one half thereof for each crank angle. And in FIG. 6, the movements of the vanes 17 and 23 of the first rotary compression element 4 and the second rotary compression element 5, respectively, and the changes in which the vane rear spaces 53 and 55 expand and contract are shown.

[0090] In addition, in FIG. 6, for the sake of easy understanding of the explanation, the time when the crank angle (the crank angle of the roller 16 of the first rotary compression element 4) is 180 degrees is shown as the figure in the upper left corner of the figure, and it is described in an arrangement that progresses to the right in order and then turns back to the figure on the lower left side of the lower row.

[0091] (Crank angles of 180 degrees, 210 degrees, and 240 degrees) In the present embodiment, as shown in FIG. 6, at the crank angles of 180 degrees, 210 degrees, and 240 degrees, the passage hole 41 of the first rotary compression element 4 is open, and the vane back-pressure side compression chamber 54 communicates with the internal space 3 of the sealed container 2. The vane back pressure is the same as the pressure of the refrigerant in the internal space 3 of the sealed container 2.

[0092] The passage hole 42 of the second rotary compression element 5 is closed, and the vane back-pressure side compression chamber 56 does not communicate with the internal space 3 of the sealed container 2. The vane back pressure is higher than the pressure of the refrigerant in the internal space 3 of the sealed container 2.

[0093] (Crank angle of 270 degrees) Next, at the time when the crank angle is 270 degrees, both the passage hole 41 of the first rotary compression element 4 and the passage hole 42 of the second rotary compression element 5 are open. And both the vane back-pressure side compression chamber 54 and the vane back-pressure side pressure chamber 56 communicate with the internal space 3 of the sealed container 2. Therefore, the vane back pressure becomes the same as the pressure of the refrigerant in the internal space 3 of the sealed container 2.

[0094] (Crank angles of 300 degrees, 330 degrees, 0 degrees, 30 degrees, and 60 degrees) At the crank angles of 300 degrees, 330 degrees, 0 degrees, 30 degrees, and 60 degrees, the passage hole 41 of the first rotary compression element 4 is closed, and the vane back-pressure side compression chamber 54 does not communicate with the internal space 3 of the sealed container 2. The vane back pressure is higher than the pressure of the refrigerant in the internal space 3 of the sealed container 2.

[0095] The passage hole 42 in the second rotary compression element 5 is open, and the vane back-pressure side compression chamber 56 communicates with the internal space 3 of the sealed container 2. The vane back pressure becomes the same as the pressure of the refrigerant in the internal space 3 of the sealed container 2.

[0096] (Crank angle 90 degrees) Next, at the crank angle, when it is 90 degrees, both the passage hole 41 of the first rotary compression element 4 and the passage hole 42 of the second rotary compression element 5 are open. And both the vane back-pressure side compression chamber 54 and the vane back-pressure side pressure chamber 56 communicate with the internal space 3 of the sealed container 2. The vane back-pressure becomes the same as the pressure of the refrigerant in the internal space 3 of the sealed container 2.

[0097] (Crank angles 120 degrees, 150 degrees) Next, at the crank angle, when it is 120 degrees and 150 degrees, the passage hole 41 of the first rotary compression element 4 is open, and the vane back-pressure side compression chamber 54 communicates with the internal space 3 of the sealed container 2. The vane back-pressure is the same as the pressure of the refrigerant in the internal space 3 of the sealed container 2.

[0098] The passage hole 42 in the second rotary compression element 5 is closed, and the vane back-pressure side compression chamber 56 does not communicate with the internal space 3 of the sealed container 2. The vane back-pressure is higher than the pressure of the refrigerant in the internal space 3 of the sealed container 2.

[0099] (Example of change of passage hole) In the above embodiment, the communication passage 38 communicating with the internal space 3 of the sealed container 2 is provided in the plate middle 14. And in the communication passage 38, the passage hole 41 is opened at a position corresponding to the vane back-pressure side compression chamber 54 of the first rotary compression element 4, and the passage hole 42 is opened at a position corresponding to the vane back-pressure side compression chamber 56 of the second rotary compression element 5, but the present invention is not limited to this embodiment.

[0100] FIG. 7 shows an example of the change. In this example of the change, in the lower support member 25 stacked on the cylinder 21 of the second rotary compression element 5, the communication passage 38 is passed along the direction along the rotation axis direction, and a part of the communication passage 38 is opened as a passage hole 42 facing the vane back-pressure side pressure chamber 56 of the second rotary compression element 5. Also, a through hole is formed in the lower support member 25 to form a communication passage 38A.

[0101] Also, extend the communication passage 38 to the plate middle 14 overlapping the vane back pressure side pressure chamber 54 of the first rotary compression element 4, and form the communication passage 38 extended to the plate middle 14 so as to face the vane back pressure side pressure chamber 54 of the first rotary compression element 4, and open the pass holes 41.

[0102] (Position of the pass hole) An example in which the pass holes 41 and 42 are opened in the communication passage 38 of the plate middle 14 so that the vane back pressure side pressure chamber 54 of the first rotary compression element 4 and the vane back pressure side pressure chamber 56 of the second rotary compression element 5 can communicate with the internal space 3 of the sealed container 2. Also, in an example in which the communication passage 38A is extended from the lower support member 25 side toward the vane back pressure side pressure chamber 56 of the first and second rotary compression elements 5 and the vane back pressure side pressure chamber 54 of the first rotary compression element 4 and the pass holes 41 and 42 are made to correspond, it is recommended that the pass holes 41 and 42 be in the following positions.

[0103] That is, the positions of the pass holes 41 and 42 in the vane back pressure side pressure chambers 54 and 56 are such that the refrigerant in the internal space 3 of the sealed container 2 enters the vane back pressure side pressure chambers 54 and 56, the pass holes 41 and 42 are closed, and the vane back pressure increased in the vane back pressure side pressure chambers 54 and 56 can be applied to the vanes 17 and 23. Thereby, the resultant force of the pressing force of the springs 49 and 50 and the vane back pressure can be applied to the vanes 17 and 23, and vane flutter can be suppressed.

[0104] Also, it is preferable that the position be such that oil as lubricating oil can be fed from the side of the rotary shaft 18 through the portion of the communication hole 38 and the pass holes 41 and 42 into the vane rear spaces 53 and 55.

[0105] Specifically, when the pass holes 41 and 42 are closed, the vane back pressure in the vane back pressure side pressure chambers 54 and 56 is higher than the pressure in the internal space 3 of the sealed container 2, and the position where vane flutter can be suppressed by the resultant force of the pressing force of the springs 49 and 50 and the vane back pressure is preferable.

[0106] Then, in terms of the crank angle, when the roller 16 of the first rotary compression element 4 reaches a position set within the range of 50 degrees to 130 degrees of the crank angle, the passage hole 41 is opened (in terms of the crank angle of the roller 22 in the second rotary compression element 5, when the roller 22 reaches a set position within the range of 230 degrees to 310 degrees, the passage hole 42 is opened), so that the back pressure of the vane back pressure side pressure chambers 54 and 56 becomes the same as the pressure in the internal space 3 of the sealed container 2.

[0107] By adopting such a configuration, it is possible to prevent an excessive pressing force from being applied to the vanes 17 and 23, increasing the sliding resistance of the vanes 17 and 23 and causing deterioration of the operating efficiency of the rotary compressor 1, and at the same time, good oil feeding can be realized.

[0108] In the present embodiment, the first rotary compression element 4 and the second rotary compression element 5 are the same except that the eccentrically rotating rollers 16 and 2 are operated with a phase difference of 180 degrees in the crank angle, and the positions of the passage holes 41 and 42 are the same and are in opposite positions.

[0109] Also, in the present embodiment, plugs 51 and 52 are arranged on the container body 8 side of the sealed container 2 in the vane back pressure side pressure chambers 54 and 56. The plugs 51 and 52 seal the vane back pressure side back pressure chambers 54 and 56, and discharge holes for discharging a liquid such as oil are formed in the space in the vane back pressure side back pressure chambers 54 and 56 when an excessive pressure rise occurs due to liquid sealing or the like. Further, the plugs 51 and 52 are provided so as to discharge a liquid such as oil into the internal space 3 of the sealed container 2 even when it is about to become an oil seal.

[0110] Also, in the present embodiment, the rollers 16 and 22 that eccentrically rotate in the first and second rotary compression elements 4 and 5 have been described as having a phase difference set to 180 degrees. However, the present invention is not limited to a phase difference of 180 degrees, and the positions of the passage holes 41 and 42 may be adjusted according to the set phase difference.

[0111] Also, in the present embodiment, the rotary compression mechanism unit 6 has been described as having a two-cylinder configuration, but the present invention is not limited to two cylinders and may be a single cylinder.

Explanation of Reference Numerals

[0112] 1…Rotary compressor 2…Sealed container 3…Internal space 4…First rotary compression element 5…Second rotary compression element 7…Electric element 8…Container body 14…Plate middle 15, 21…Cylinder 16, 22…Roller 17, 23…Vane 18…Rotating shaft 39, 40…Vane slot 41, 42…Passage hole 49, 50…Spring 53, 55…Vane rear space 54, 56…Vane back pressure side pressure chamber

Claims

1. A hermetic container includes an electric element and a rotary compression element driven by a rotary shaft of the electric element, wherein the rotary compression element includes a cylinder, a roller disposed on an eccentric portion formed on the rotary shaft and eccentrically rotating inside the cylinder, a vane moving from the top dead center to the bottom dead center and contacting the circumferential surface of the roller to partition the inside of the cylinder into a high-pressure chamber and a low-pressure chamber, a vane slot formed in the cylinder and accommodating the vane movably, and a spring provided in the vane slot and biasing the vane toward the bottom dead center. A vane back pressure side pressure chamber capable of forming a vane back pressure higher than the pressure of the space inside the hermetic container is provided in a vane back space on the side of the vane slot opposite to the roller. A passage hole communicating with the space inside the hermetic container is opened on a sliding contact surface of the vane back pressure side pressure chamber with the vane. A rotary compressor, characterized in that at least a part of the passage hole is closed by the vane pushed up by the roller.

2. The vane moves in the vane slot from the top dead center to the bottom dead center range along with the eccentric rotation of the roller. The rotary compressor according to claim 1, wherein the passage hole is provided at a position where it is in an open state when the vane is near the bottom dead center.

3. The rotary compressor according to claim 1, wherein the vane back pressure side pressure chamber communicates with the space inside the sealed container when the passage hole is open, and the vane back pressure in the vane back pressure side pressure chamber is the same as the pressure of the space inside the hermetic container.

4. Two rotary compression elements are provided side by side in the hermetic container with a plate middle therebetween. The plate middle includes a communication passage connecting from a portion on the rotary shaft side to the vane back pressure side pressure chambers of the two rotary compression elements respectively. The rotary compressor according to claim 1, wherein a portion of the communication passage on the space side inside the sealed container is open, and the passage hole is provided at a position corresponding to the vane back pressure side pressure chamber in each of the two rotary compression elements.

Images