JP2009127440A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly efficient and highly reliable low pressure chamber system scroll compressor. <P>SOLUTION: This scroll compressor 1 includes a fixed scroll 5, a turning scroll 6 forming a compression space together with the fixed scroll 5, a frame 9 forming a back pressure chamber 9b on a back face of the turning scroll 6, a sealed vessel 2 storing a compression element 3 and forming a low pressure chamber for making a refrigerant flow in from a cycle, and an oil separating part 13 separating lubricating oil of a working fluid compressed and delivered from the compression space. This scroll compressor 1 also includes a back pressure chamber oil feeding passage 5g supplying the lubricating oil 12 of the oil separating part to the back pressure chamber 9b, and a back pressure control valve 11 controlling pressure of the back pressure chamber 9b in predetermined intermediate pressure by draining the lubricating oil of the back pressure chamber 9b to the low pressure chamber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a scroll compressor, and is particularly suitable for a low-pressure chamber type scroll compressor used in a heat pump hot water supply device, a refrigeration air conditioner, and the like.

  As conventional scroll compressors, there are a high-pressure chamber type scroll compressor in which the inside of a sealed container has a discharge pressure, and a low-pressure chamber type scroll compressor in which the inside of the sealed container has a low-pressure chamber with suction pressure.

  In a high-pressure chamber type scroll compressor, a back pressure chamber is formed on the back of the orbiting scroll, and lubricating oil stored in a sealed container in which a refrigerant is melted is supplied to the back pressure chamber using a differential pressure. An advantage that leakage loss of the lap tooth tip can be easily reduced by setting the pressure chamber to an intermediate pressure that is a pressure between the suction pressure and the discharge pressure and pressing the orbiting scroll against the fixed scroll. Have

  On the other hand, the low-pressure chamber type scroll compressor has an advantage that the hermetic container can be thinned and the compressor can be reduced in weight.

  A conventional low-pressure chamber type scroll compressor is disclosed in Japanese Patent Laid-Open No. 6-17773 (Patent Document 1).

  The scroll compressor of Patent Document 1 includes a compression element including a first scroll and a second scroll on one side of a casing, and a motor having a drive shaft for driving the second scroll on the other side. A suction housing is opened in the motor side chamber, and a bearing housing that supports the compression element side of the drive shaft with respect to the motor is provided, and lubricating oil is provided in a sliding portion including a bearing portion of the bearing housing through an oil supply passage provided in the drive shaft. A lubrication pump for supplying oil is provided at the end of the drive shaft.

  In Patent Document 1, a housing through hole having one end communicating with the sliding portion of the drive shaft and the other end opening toward the bottom of the casing is formed in the bearing housing, and one end is formed at the other end of the housing through hole. An assembly having an assembly communication hole communicating with the assembly is attached to the bearing housing, and a pipe having one end communicating with the other end of the assembly communication hole and the other end communicating with the anti-compression element side of the motor side chamber is attached to the assembly. Thus, the oil recovery passage is configured by the housing through hole, the assembly communication hole, and the pipe. Further, in Patent Document 1, a discharge chamber having a discharge pipe opened on the side opposite to the motor of the compression element is provided, and an oil return pipe having one end opened in the discharge chamber and the other end opened in the collecting chamber communication hole is provided. Thus, the lubricating oil in the discharge chamber is guided to the oil recovery path.

  Another conventional low-pressure chamber type scroll compressor is disclosed in Japanese Patent Laid-Open No. 2005-180320 (Patent Document 2).

  In the scroll compressor of Patent Document 2, the lubricating oil stored in the discharge chamber is passed through the recess formed in the orbiting scroll from the oil supply passage formed in the fixed scroll once per rotation of the crankshaft. It flows into a recess formed in the fixed scroll. Lubricating oil that has flowed into the recess of the fixed scroll is supplied from the recess to the back pressure chamber, and is supplied from the back pressure chamber to the middle of the compression chamber through an intermediate hole. Thus, the Oldham ring is lubricated and the back pressure chamber is boosted to a pressure intermediate between the discharge pressure and the suction pressure by the refrigerant dissolved in the lubricating oil. The scroll compressor disclosed in Patent Document 2 can press the orbiting scroll against the fixed scroll and reduce leakage at the tip of the scroll wrap even in the low pressure chamber system. Further, in Patent Document 2, lubricating oil in the discharge chamber is caused to flow into another recess of the orbiting scroll once during one rotation of the crankshaft from another oil supply passage formed in the fixed scroll, and thus the orbiting scroll performs the orbiting motion. Accordingly, the lubricating oil is discharged into the sealed container through still another oil supply passage formed in the fixed scroll.

JP-A-6-17773 JP-A-2005-180320

  In the scroll compressor of Patent Document 1 described above, since the lubricating oil is returned through the oil return pipe from the discharge chamber serving as the discharge pressure to the assembly communication hole serving as the suction pressure, it is used for the refrigeration cycle apparatus in which the pressure condition varies. In this case, it is difficult to set the passage resistance of the oil return pipe, and depending on the conditions, the lubricating oil returns too much and the refrigerant blows out, which may cause a significant decrease in volumetric efficiency. In particular, when carbon dioxide, which has a large pressure difference between the discharge pressure and the suction pressure, is used as the refrigerant, the above problem appears remarkably. In addition, since the second scroll is not configured to be pressed against the first scroll, the gap between the wrap tooth tips must be managed with high accuracy on the order of several μm in order to reduce leakage of the scroll wrap tooth tips. In addition, when the gap between the wrap tooth tips is increased, there is a possibility of incurring a cost increase such as the need to use a tip seal.

  Further, in the scroll compressor of Patent Document 2 described above, since the pressure of the back pressure chamber is controlled by the intermediate hole that communicates the compression chamber and the back pressure chamber, the intermediate pressure of the back pressure chamber changes depending on the operating conditions. Mechanical loss can increase.

  An object of the present invention is to provide a low-pressure chamber type scroll compressor having high efficiency and high reliability. Other objects and advantages of the present invention will become apparent from the following description.

  In order to achieve the above-described object, the present invention provides a fixed scroll provided with a fixed scroll wrap, a revolving scroll wrap that meshes with the fixed scroll wrap, and a revolving scroll that forms a compression chamber together with the fixed scroll; A frame that forms a back pressure chamber on the back surface of the scroll; a compression container comprising the fixed scroll, the orbiting scroll, and the frame; a sealed container that forms a low pressure chamber into which a refrigerant flows from a cycle; and the compression chamber In the scroll compressor, comprising: an oil separation part that separates the lubricating oil of the working fluid that is compressed and discharged; and a back pressure chamber oil supply path that supplies the lubricating oil of the oil separation part to the back pressure chamber. There is provided a back pressure control valve for discharging the lubricating oil in the pressure chamber to the low pressure chamber and controlling the pressure in the back pressure chamber to a predetermined intermediate pressure.

A more preferable specific configuration example of the present invention is as follows.
(1) An electric element comprising a stator fixed to the hermetic container and a rotor rotatably provided in the stator, and disposed in the hermetic container so as to face the compression element; A crankshaft penetrating the frame and the rotor, supported by the frame via a main bearing, and driving the orbiting scroll via the orbiting bearing, and an end portion on the side opposite to the compression element of the crankshaft And an oil supply pump for supplying lubricating oil in the low pressure chamber located on the side opposite to the compression element from the electric element to the sliding portion of the crankshaft through an oil supply hole provided in the crankshaft.
(2) In (1), the back pressure control valve is provided in the frame, and the lubricating oil flowing out from the sliding portion of the crankshaft and the lubricating oil flowing out from the back pressure control valve are merged. Established a common discharge route for common discharge.
(3) In the above (2), the common discharge path is formed by a discharge pipe that penetrates the electric element from the frame and guides lubricating oil to the low pressure chamber on the side opposite to the compression element from the electric element.
(4) In (1), a discharge pipe is provided for guiding the lubricating oil flowing out from the back pressure control valve through the electric element to the low pressure chamber on the side opposite to the compression element from the electric element.
(5) In (1), the suction port of the fixed scroll for sucking the working fluid into the compression chamber and the back pressure control valve are shifted by 90 ° or more in the circumferential direction around the central axis of the sealed container. It was provided.
(6) In (1), a discharge space for discharging lubricating oil that lubricates the sliding portion of the crankshaft is formed in the frame, the back pressure control valve is provided in the frame, and the discharge space is discharged into the discharge space. And a common discharge path for discharging the lubricant and the lubricant discharged from the back pressure control valve in common.
(7) In the above (6), the common discharge path is formed by a discharge pipe that penetrates the electric element from the frame and guides lubricating oil to the low pressure chamber on the side opposite to the compression element from the electric element.
(8) In the above (7), the back pressure control includes a back pressure port that discharges lubricating oil including refrigerant from the back pressure chamber, a valve plate that closes the back pressure port, and a spring that presses the valve plate. A spring accommodating portion that constitutes a valve and accommodates the spring of the back pressure control valve is provided by sharing a part of the discharge space.
(9) An oil separation case that forms a discharge chamber in which the working fluid compressed in the compression chamber is discharged through a discharge port of the fixed scroll and an oil separation chamber in which the working fluid in the discharge chamber is discharged through a discharge passage. The oil separation unit is provided, and a cylindrical member is provided that causes the flow of the working fluid discharged from the discharge passage into the oil separation chamber to be swirled and then flows out of the compressor.
(10) In (1), a back pressure discharge space for discharging the lubricating oil through the back pressure control valve is formed by the frame and the frame cover, and the refrigerant foamed from the lubricating oil in the back pressure discharging space is formed. A vent hole for discharging is provided in the frame cover.
(11) In (1), a back pressure discharge passage for discharging lubricating oil from the back pressure control valve is formed so as to communicate with an outer peripheral groove formed on the outer periphery of the frame.
(12) Carbon dioxide is used as the working fluid.

  According to the present invention, a highly efficient and highly reliable low-pressure chamber type scroll compressor can be obtained.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent.

(First embodiment)
A scroll compressor according to a first embodiment of the present invention will be described with reference to FIGS.

  First, the overall configuration, operation, and function of the scroll compressor 1 of the present embodiment will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of a scroll compressor according to the first embodiment of the present invention.

  The scroll compressor 1 is configured by housing a compression element 3 and an electric element 4 including a rotor 4a and a stator 4b in a hermetic container 2. The sealed container 2 has a horizontally long cylindrical shape, and the compression element 3 and the electric element 4 are juxtaposed side by side in the scroll compressor 1.

  The compression element 3 includes a fixed scroll 5, a turning scroll 6, and an Oldham ring 7 that prevents the turning of the turning scroll 6. The fixed scroll 5 includes a spiral fixed scroll wrap 5a and a fixed scroll end plate 5b on which the wrap 5a stands upright. The orbiting scroll 6 has a spiral-shaped orbiting scroll wrap 6a and an orbiting scroll end plate 6b on which the wrap 6a stands upright. The fixed scroll 5 and the orbiting scroll 6 mesh with both wraps 5a and 6a to form a compression chamber. An orbiting bearing 6 c is provided in a boss portion 6 f that protrudes from the rear surface of the orbiting scroll 6.

  A discharge port 5 c for discharging the refrigerant gas compressed in the compression chamber is formed at a substantially central portion of the fixed scroll 5. The discharge port 5c is opened on the counter-electric element side. A suction port 5d is formed on the outer peripheral portion of the fixed scroll 5 to allow the refrigerant to flow into the compression chamber. The suction port 5d is configured to communicate the low pressure chamber in the sealed container 2 with the suction chamber 5f of the compression element 4.

  A suction pipe 16 penetrating the hermetic container 2 and communicating with the low pressure chamber is provided, and refrigerant gas flows from the cycle side through the suction pipe 16 into the low pressure chamber. The refrigerant gas flowing into the sealed container 2 from the suction pipe 16 is sucked into the compression element 3 and compressed, and discharged from the discharge port 5c to the discharge chamber 13a.

  The scroll compressor 1 having such a configuration is a low-pressure chamber system in which the sucked refrigerant flows into the sealed container 2, and has an advantage that the thickness of the sealed container 2 can be reduced and the compressor can be reduced in weight. This is particularly effective when carbon dioxide having a high operating pressure of 10 MPa or more is used as the refrigerant.

  The crankshaft 8 links the compression element 3 and the electric element 4, and the rotor 4 a of the electric element 4 is press-fitted. The crankshaft 8 is rotatably supported by two bearings, a main bearing 9a and a sub-bearing 22, arranged on both sides of the rotor 4a. One end of the crankshaft 8 is fitted in the orbiting bearing 6 c and is rotated with the rotation of the electric element 4 to drive the orbiting scroll 6. The main bearing 9 a is mounted in the central hole of the frame 9.

  The frame 9 forms a back pressure chamber 9 b on the back side of the end plate 6 b of the orbiting scroll 6. Further, a seal ring 10 is attached to the frame 9, and the seal ring 10 is sealed so that the refrigerant gas in the back pressure chamber 9b does not leak into the swing bearing 6c and the main bearing 9a. The pressure (back pressure) in the back pressure chamber 9b is controlled by the back pressure control valve 11 to an intermediate pressure between the discharge pressure and the suction pressure. The back pressure control valve 11 is provided in the frame 9.

  Lubricating oil 12 is stored in the bottom surface of the sealed container 2. In other words, the lubricating oil 12 is stored at the bottom of the low pressure chamber of the sealed container 2 into which the refrigerant gas flows from the refrigeration cycle.

  The oil separation case 13 is a member for constituting an oil separation part, and is constituted by a plurality of cases (two in the illustrated example). The oil separation case 13 is formed on the side of the stationary scroll 5 on the side opposite to the electric element, a discharge chamber 13a that houses a discharge valve 14 that opens and closes the discharge port 5c, and an oil separation chamber 13b that separates refrigerant and lubricating oil. ing. The discharge chamber 13a and the oil separation chamber 13b communicate with each other through a discharge passage 13c provided in the oil separation case 13.

  The refrigerant gas compressed in the compression chamber is discharged to the discharge chamber 13a through the discharge port 5c, and further flows out to the oil separation chamber 13b through the discharge passage 13c. In the oil separation chamber 13b, the lubricating oil 12 contained in the refrigerant gas is separated and stored at the bottom of the oil separation case 13. A discharge pipe 15 penetrating the sealed container 2 and opened into the oil separation chamber 13b is provided. The refrigerant gas from which the lubricating oil has been separated flows out from the oil separation chamber 13b through the discharge pipe 15 to the refrigeration cycle.

  A lubricating oil passage 8 a is formed inside the crankshaft 8, and a spiral groove 8 b is formed on the surface of the crankshaft 8. The lubricating oil passage 8a is formed through the center of the crankshaft 8 to the left and right, and its end on the compression element side is opened to face the bottom of the boss 6f, and its end on the side opposite to the compression element The part is opened in the tip surface. The spiral groove 8b communicates with the lubricating oil passage 8a through a lateral hole 8c formed in the crankshaft 8.

  Next, the supply and recovery of the lubricating oil 12 will be described with reference to FIGS. 2 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 3 is a cross-sectional view taken along the line BB in FIG. 2 for explaining oil supply to the compression chamber, and FIG. 4 is an explanatory view of an oil separation function in the oil separation chamber in FIG. FIG. 5 is an enlarged view of an oil supply mechanism from the discharge chamber to the back pressure chamber of FIG.

  An oil supply pump 17 such as a trochoid pump is installed at the end of the crankshaft 8 on the side opposite to the compression element. The suction side of the oil supply pump 17 communicates with the lubricating oil 2 stored in the low pressure chamber, and the discharge side of the oil supply pump 17 communicates with the lubricating oil passage 8a.

  The lubricating oil 12 stored in the lower part of the sealed container 2 is supplied to the lubricating oil passage 8 a by the oil supply pump 17. A part of the lubricating oil 12 supplied to the lubricating oil passage 8a is supplied to the spiral groove 8b through the lateral hole 8c and lubricates the main bearing portion 9a. The lubricating oil 12 that has not been discharged from the horizontal hole 8c is supplied to the anti-wrap surface of the orbiting scroll 6 through the lubricating oil passage 8a, and is then supplied to the spiral groove 8d to lubricate the orbiting bearing 6c. The lubricating oil 12 that lubricates the slewing bearing 6c and the main bearing 9a flows toward the thrust receiver 8d of the crankshaft 8, and is merged in the lubricating oil discharge space 9c. The lubricating oil discharge space 9 c is a space surrounded by the boss portion 6 f, the crankshaft 8 and the frame 9.

  The lubricating oil 12 merged in the lubricating oil discharge space 9c is returned to the lubricating oil 12 in the low pressure chamber on the oil supply pump side (low pressure chamber on the side opposite to the compression element from the electric element 4) through the discharge pipe 18. A lubricating oil discharge hole 9g is formed in the frame 9 such that an upper end portion on one side opens into the lubricating oil discharge space 9c and a lower end portion on the other side opens into the low pressure chamber. The discharge pipe 18 is connected to the lower end opening of the lubricating oil discharge hole 9g and communicates with the lubricating oil discharge space 9c via the lubricating oil discharge hole 9g.

  With such a configuration, the lubricating oil that has lubricated the bearings 6c and 9a that are the sliding portions of the crankshaft 8 is returned to the low pressure chamber on the oil supply pump side without being exposed to the space on the compression element side of the electric element 4. Therefore, it is not stirred by the electric element 4 or the like.

  As shown in FIGS. 2 and 3, the other lubricating oil 12 that is not used for lubricating the orbiting bearing 6c and the main bearing 9a is a first oil supply passage 6d formed in the orbiting scroll 6 from the bottom of the boss portion 6f. Is introduced to the outer peripheral groove 5e of the fixed scroll 5, supplied to the suction chamber 5f, and used as an internal seal of the compression chamber. Here, the first oil supply passage 6 d and the outer peripheral groove 5 e are intermittently communicated by the orbiting motion of the orbiting scroll 6. This communication section can be changed depending on the position of the first oil supply passage 6d, and by setting this communication section, it becomes possible to supply a necessary amount of lubricating oil for the internal seal of the compression chamber.

  As described above, the lubricating oil 12 supplied to the compression chamber is discharged from the discharge port 5c together with the refrigerant gas, enters the discharge chamber 13a, and flows out from there through the discharge passage 13c to the oil separation chamber 13b. As shown in FIG. 4, the refrigerant gas and the lubricating oil 12 that have flowed into the oil separation chamber 13c are swirled in the oil separation chamber 13b, and the high-density lubricating oil 12 and the low-density refrigerant are separated by centrifugal force. The lubricating oil 12 is stored in the lower part of the oil separation chamber 13b.

  As shown in FIG. 5, the lubricating oil 12 separated in the discharge chamber 13a swirls through a second oil supply passage (back pressure chamber oil supply route) 5g formed in the oil separation case 13 and the fixed scroll 5. The first recess 6e formed in the scroll 6 is entered. The first indentation 6 e communicates with the second indentation 5 h formed in the fixed scroll 5 by the orbiting motion of the orbiting scroll 5 once during one revolution of the crankshaft 8. During this communication, the lubricating oil 12 enters the second recess 5h from the first recess 6e. The lubricating oil 12 that has entered the first recess 6e is supplied to the back pressure chamber 9b when the first recess 6e communicates with the back pressure chamber 9b. The lubricating oil 12 supplied to the back pressure chamber 9b is used for lubrication of the Oldham ring 7, and the pressure in the back pressure chamber 9b is increased by foaming of the refrigerant dissolved in the lubricating oil 12. Accordingly, the Oldham ring 7 can be lubricated and the pressure in the back pressure chamber 9b can be increased with a simple configuration.

  Here, the volume of the second indentation 5h is set to the larger amount of oil supply, which is either the amount of oil required for lubricating the Oldham ring 7 or the amount of oil required for increasing the pressure in the back pressure chamber 9b, Both lubrication of the Oldham ring 7 and pressure increase in the back pressure chamber 9b can be achieved.

  Next, the back pressure control of the back pressure chamber 9b will be described with reference to FIGS. 6 is an enlarged view of the back pressure control valve portion of FIG.

  The back pressure in the back pressure chamber 9b is controlled by the back pressure control valve 11 to an intermediate pressure between the discharge pressure and the suction pressure. The back pressure control valve 11 includes a back pressure port 11a for discharging the refrigerant and the lubricating oil 12 from the back pressure chamber 9b, a valve plate 11b for closing the back pressure port 11a, a spring 11c for pressing the valve plate 11b, It consists of a press-fitting piece 11d to which a spring 11c is attached and press-fitted into the frame 9.

  A back pressure control valve chamber 11e having the same central axis as the back pressure port 11a and communicating with the back pressure port 11a is formed in the frame 9. The back pressure control valve chamber 11e is formed so as to intersect the lubricating oil discharge hole 9g from the surface of the frame 9 on the electric element side. In the back pressure control valve chamber 11e, a valve plate 11b, a spring 11c, and a press-fitting piece 11d are sequentially installed from the back pressure port 11a side.

  Since the atmosphere on the back pressure control valve chamber 11e side of the spring 11c is the suction pressure, if the refrigerant dissolved in the lubricating oil 12 supplied from the oil separation chamber 13b to the back pressure chamber 9b is foamed and the back pressure is increased, the back pressure is increased. And the suction pressure acts as an acting force on the valve plate 11b closing the back pressure port 11a. When this acting force becomes larger than the pressing force of the spring 11c, the spring 11c contracts, the discharge port 11a opens, and the lubricating oil 12 and refrigerant in the back pressure chamber 9b are discharged to the back pressure control valve chamber 11e. As a result, the back pressure is controlled by suction pressure + spring force / discharge port cross-sectional area.

  However, if the back pressure is set too high, the sliding loss between the orbiting scroll 6 and the fixed scroll 5 increases and the efficiency decreases, so it is necessary to adjust the back pressure to the optimum value for efficiency. Regarding the point, the back pressure can be adjusted to the optimum value in terms of efficiency by adjusting the spring force of the spring 11c and the cross-sectional area of the discharge port 11a. The back pressure control by the back pressure control valve 11 can maintain the back pressure at a predetermined pressure even if the operating conditions change.

  Further, the lubricating oil 12 discharged from the discharge port 11a merges with the lubricating oil 12 that has lubricated the bearing and entered the lubricating oil discharge space 9c, and returns to the oil pump 17 side through the discharge pipe 18. 4 is not stirred.

  As described above, in the present embodiment, in the low pressure chamber system in which the sealed container 2 is the suction pressure, the pressure in the back pressure chamber 9b is controlled to the optimum value for efficiency and the amount of oil necessary for lubrication of the Oldham ring 7 is increased. Since it can be supplied to the back pressure chamber 9b, a high-performance and highly reliable scroll compressor can be provided. In addition, since the lubricating oil 12 that lubricates the bearing and the lubricating oil 12 that is discharged from the back pressure chamber 9b can be reliably returned to the oil supply pump without being stirred by the electric element 4, a decrease in the oil level in the sealed container 2 is suppressed. can do. Further, since the mist-like lubricating oil 12 is not sucked, the oil discharge amount can be reduced as a result.

  In the present embodiment, the horizontal scroll compressor has been described in detail, but it can be easily applied to a vertical scroll compressor.

(Second Embodiment)
Next, the scroll compressor 1 of 2nd Embodiment of this invention is demonstrated using FIGS. 7-9. 7 is a cross-sectional view showing a main part of a scroll compressor according to the second embodiment of the present invention, FIG. 8 is a cross-sectional view taken along the line CC in FIG. 7, and FIG. 9 is a cross-sectional view taken along the line DD in FIG. The second embodiment is different from the first embodiment in the points described below, and the other points are basically the same as those in the first embodiment, and thus redundant description is omitted.

  In the second embodiment, as shown in FIG. 8, the back pressure control valve 11 is provided at a position away from the discharge pipe 18. That is, the back pressure control valve 11 is provided at a position shifted in the circumferential direction with respect to the central axis of the crankshaft 8.

  When the back pressure becomes greater than the suction pressure + spring force / discharge port cross-sectional area, the spring 11c contracts and the discharge port 11a opens, and the lubricating oil 12 and refrigerant in the back pressure chamber 9b are discharged to the back pressure control valve chamber 11e. The The lubricating oil 12 and the refrigerant are discharged from the back pressure control valve chamber 11e to the back pressure discharge space 19a through the back pressure discharge passage 9d. The back pressure discharge space 19 a is a space formed by the frame 9 and the frame cover 19. In this back pressure discharge space 19a, the low density refrigerant is discharged to the sealed container 2 through the gas vent hole 19b in the upper part of the frame cover 19 shown in FIG. 7, and the high density lubricant 12 passes through the lubricant discharge hole 9e. Then, it merges with the lubricating oil 12 that has lubricated the bearing, returns to the oil pump 17 side through the discharge pipe 18.

  As described above, according to the second embodiment, the refrigerant discharged from the back pressure port 11a is guided to the back pressure discharge space 19a and discharged from the gas vent hole 19b into the sealed container 2, so that the refrigerant is mixed into the bearing portion. Thus, a more reliable scroll compressor can be provided. This second embodiment is an invention suitable for a horizontal scroll compressor.

(Third embodiment)
Next, the scroll compressor 1 of 3rd Embodiment of this invention is demonstrated using FIGS. 10-12. 10 is a cross-sectional view showing a main part of a scroll compressor according to a third embodiment of the present invention, FIG. 11 is a cross-sectional view taken along line EE in FIG. 10, and FIG. 12 is a cross-sectional view taken along line FF in FIG. The third embodiment is different from the first embodiment in the points described below, and the other points are basically the same as those in the first embodiment, and thus redundant description is omitted.

  In the third embodiment, the lubricating oil 12 supplied to the spiral groove 8b and lubricated the main bearing portion 9a, and the lubricating oil 12 supplied to the spiral groove 8d and lubricated the swivel bearing 6c are lubricated. They merge in the space 9 c and flow into a back pressure discharge space 20 a formed by the frame 9 and the frame cover 20. The lubricating oil 12 that has flowed into the back pressure discharge space 20a passes through the discharge pipe 18 and returns to the oil pump 17 side.

  On the other hand, when the back pressure exceeds the suction pressure + spring force / discharge port cross-sectional area, the spring 11c contracts and the discharge port 11a opens to discharge the lubricant 12 and the refrigerant in the back pressure chamber 9b to the back pressure control valve chamber 11e. Then, it flows out into the outer peripheral groove 9f of the frame 9 through the back pressure discharge passage 9d. Here, the low-density refrigerant passes through the outer peripheral groove 9 f of the frame 9 and the outer peripheral groove 5 i of the fixed scroll 5 and is discharged to the sealed container 2, and the high-density lubricating oil 12 is formed by the frame 9 and the frame cover 20. It flows into the back pressure discharge space 20a. The lubricating oil 12 that has flowed into the back pressure discharge space 20a merges with the lubricating oil 12 that has lubricated the bearings, and returns to the oil pump 17 side through the discharge pipe 18.

  As described above, according to the third embodiment, the refrigerant discharged from the back pressure port 11a is discharged from the frame 9 and the outer peripheral grooves 5i and 9f of the fixed scroll 5 to the sealed container 2, so that the refrigerant is mixed into the bearing portion. Therefore, a more reliable scroll compressor can be provided. This embodiment is an invention suitable for a vertical scroll compressor.

(Fourth embodiment)
Next, the scroll compressor 1 of 4th Embodiment of this invention is demonstrated using FIGS. 13-15. 13 is a cross-sectional view showing a main part of a scroll compressor according to a fourth embodiment of the present invention, FIG. 14 is a cross-sectional view taken along line GG in FIG. 13, and FIG. 15 is a cross-sectional view taken along line HH in FIG. The fourth embodiment is different from the first embodiment in the following points, and the other points are basically the same as those in the first embodiment, and thus redundant description is omitted.

  In the fourth embodiment, the lubricating oil supplied to the spiral groove 8b and lubricating the main bearing portion 9a and the lubricating oil supplied to the spiral groove 8d and lubricated the swivel bearing 6c are the lubricating oil discharge space 9c. And then returns to the oil pump 17 side through the discharge pipe 18.

  On the other hand, when the back pressure exceeds the suction pressure + spring force / discharge port cross-sectional area, the spring 11c contracts and the discharge port 11a opens to discharge the lubricant 12 and the refrigerant in the back pressure chamber 9b to the back pressure control valve chamber 11e. Then, the oil returns to the oil pump 17 side from the back pressure discharge passage 9d through the back pressure discharge pipe 21.

  As described above, according to the fourth embodiment, since the refrigerant passage discharged from the back pressure port 11a and the passage of the lubricating oil 12 that lubricates the bearing are completely partitioned, the refrigerant is mixed into the bearing portion. Therefore, a more reliable scroll compressor can be provided. In the fourth embodiment, the horizontal scroll compressor has been described. However, the horizontal scroll compressor can be easily applied.

It is a longitudinal section of the scroll compressor concerning a 1st embodiment of the present invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is explanatory drawing of the oil separation function in the oil separation chamber of FIG. It is an oil supply mechanism enlarged view from the discharge chamber of FIG. 1 to a back pressure chamber. FIG. 2 is an enlarged view of the back pressure control valve of FIG. 1. It is sectional drawing which shows the principal part of the scroll compressor which concerns on 2nd Embodiment of this invention. It is CC sectional drawing of FIG. It is DD sectional drawing of FIG. It is sectional drawing which shows the principal part of the scroll compressor which concerns on 3rd Embodiment of this invention. It is EE sectional drawing of FIG. It is FF sectional drawing of FIG. It is sectional drawing which shows the principal part of the scroll compressor which concerns on 4th Embodiment of this invention. It is GG sectional drawing of FIG. It is HH sectional drawing of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Scroll compressor, 2 ... Sealed container, 3 ... Compression element, 4 ... Electric element, 4a ... Rotor, 4b ... Stator, 5 ... Fixed scroll, 5a ... Wrap, 5b ... End plate, 5c ... Discharge port, 5d ... suction port, 5e ... outer peripheral groove, 5f ... suction chamber, 5g ... second oil supply passage (back pressure chamber oil supply passage), 5h ... second recess, 5i ... outer peripheral groove, 6 ... turning scroll, 6a ... lap , 6b ... end plate, 6c ... slewing bearing, 6d ... first oil supply passage, 6e ... first recess, 6f ... boss part, 7 ... Oldham ring, 8 ... crankshaft, 8a ... lubricating oil passage, 8b ... spiral Groove, 8c ... Horizontal hole, 8d ... Thrust receiver, 9 ... Frame, 9a ... Main bearing, 9b ... Back pressure chamber, 9c ... Lubricating oil discharge space, 9d ... Back pressure discharging passage, 9e ... Lubricating oil discharge hole, 9f ... Peripheral groove, 9 g ... Lubricating oil discharge hole, 10 ... Seal ring, 11 ... Back pressure Control valve, 11a ... back pressure port, 11b ... valve plate, 11c ... spring, 11d ... press-fitting piece, 11e ... back pressure control valve chamber, 12 ... lubricating oil, 13 ... oil separation case (oil separation part), 13a ... discharge Chamber, 13b ... oil separation chamber, 13c ... discharge passage, 14 ... discharge valve, 15 ... discharge pipe, 16 ... suction pipe, 17 ... oil pump, 18 ... discharge pipe, 19 ... frame cover, 19a ... back pressure discharge space, 19b ... Gas vent hole, 20 ... Frame cover, 20a ... Back pressure discharge space, 21 ... Back pressure discharge pipe, 22 ... Sub bearing.

Claims (13)

A fixed scroll provided with a fixed scroll wrap;
A revolving scroll wrap that meshes with the fixed scroll wrap, and a revolving scroll that forms a compression chamber together with the fixed scroll;
A frame forming a back pressure chamber on the back of the orbiting scroll;
A sealed container that houses a compression element composed of the fixed scroll, the orbiting scroll, and the frame, and that forms a low-pressure chamber into which refrigerant flows from a cycle;
An oil separation part for separating the lubricating oil of the working fluid that is compressed and discharged from the compression chamber;
In a scroll compressor comprising a back pressure chamber oil supply path for supplying lubricating oil of the oil separation section to the back pressure chamber,
A scroll compressor comprising a back pressure control valve that discharges lubricating oil in the back pressure chamber to the low pressure chamber and controls the pressure in the back pressure chamber to a predetermined intermediate pressure. In claim 1,
A stator provided fixed to the sealed container and a rotor rotatably provided in the stator, and an electric element disposed in the sealed container facing the compression element;
A crankshaft provided through the frame and the rotor, supported by the frame via a main bearing, and driving the orbiting scroll via an orbiting bearing;
Provided at the end of the crankshaft on the side of the anti-compression element and supplying lubricating oil in the low-pressure chamber located on the side of the anti-compression element from the electric element to the sliding portion of the crankshaft through an oil supply hole provided in the crankshaft A scroll compressor characterized by comprising an oil supply pump. In claim 2,
The back pressure control valve is provided in the frame,
A scroll compressor characterized in that a common discharge passage is provided for joining the lubricating oil flowing out from the sliding portion of the crankshaft and the lubricating oil flowing out from the back pressure control valve together and discharging them. In claim 3,
The scroll compressor characterized in that the common discharge passage is formed by a discharge pipe that penetrates the electric element from the frame and guides lubricating oil to the low pressure chamber on the side opposite to the compression element from the electric element. In claim 2,
A scroll compressor characterized in that a discharge pipe is provided for guiding the lubricating oil flowing out from the back pressure control valve through the electric element to a low pressure chamber on the side opposite to the compression element from the electric element. In claim 2,
Scroll compression, wherein the suction port of the fixed scroll for sucking the working fluid into the compression chamber and the back pressure control valve are provided at positions shifted by 90 ° or more in the circumferential direction around the central axis of the hermetic container. Machine. In claim 2,
Forming a discharge space in the frame for discharging lubricating oil that has lubricated the sliding portion of the crankshaft;
The back pressure control valve is provided in the frame,
The scroll compressor characterized by having provided the common discharge path which joins the lubricating oil discharged to the said discharge space, and the lubricating oil discharged | emitted from the said back pressure control valve, and discharges in common. In claim 7,
The scroll compressor characterized in that the common discharge passage is formed by a discharge pipe that penetrates the electric element from the frame and guides lubricating oil to the low pressure chamber on the side opposite to the compression element from the electric element. In claim 8,
The back pressure control valve is configured to include a back pressure port that discharges lubricating oil including refrigerant from the back pressure chamber, a valve plate that closes the back pressure port, and a spring that presses the valve plate,
A scroll compressor characterized in that a spring accommodating portion for accommodating a spring of the back pressure control valve is provided in common with the discharge space. In claim 1,
An oil separation case that forms a discharge chamber through which the working fluid compressed in the compression chamber is discharged through a discharge port of the fixed scroll and an oil separation chamber in which the working fluid in the discharge chamber is discharged through a discharge passage; Configure the oil separator,
A scroll compressor characterized in that a cylindrical member is provided for making the flow of the working fluid discharged from the discharge passage into the oil separation chamber into a swirl flow and then flowing out of the compressor. In claim 2,
A back pressure discharge space for discharging lubricating oil through the back pressure control valve is formed by the frame and the frame cover,
A scroll compressor, wherein the frame cover is provided with a vent hole for discharging the refrigerant foamed from the lubricating oil in the back pressure discharge space. In claim 2,
A scroll compressor, wherein a back pressure discharge passage for discharging lubricating oil from the back pressure control valve is formed so as to communicate with an outer peripheral groove formed on an outer periphery of the frame. In claim 1,
A scroll compressor using carbon dioxide as the working fluid.

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