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Scroll compressor
US20240410367A1
United States
- Inventor
Masaya Okamoto Koji Masumoto Shuhei Koyama - Current Assignee
- Mitsubishi Electric Corp
Description
translated from
-
[0001] This application is a U.S. national stage application of PCT/JP2021/048198 filed on Dec. 24, 2021, the contents of which are incorporated herein by reference. -
[0002] The present disclosure relates to a scroll compressor. -
[0003] There has been known a scroll compressor serving as a compressor used for, for example, an air-conditioning apparatus or a refrigeration apparatus. For example, the scroll compressor disclosed inPatent Literature 1 includes: a shell; a main frame fixed to an inner wall surface of the shell; a fixed scroll fixed to the inner wall surface of the shell and including a fixed base plate provided with a first scroll body; and an orbiting scroll supported by the main frame so as to orbit around the fixed scroll and including an orbiting base plate provided with a second scroll body meshing with the first scroll body. In the scroll compressor, a compression chamber in which refrigerant is compressed is formed between the first scroll body and the second scroll body by meshing the first scroll body and the second scroll body. The main frame has a suction port for introducing refrigerant from a low-pressure space of the shell into the compression chamber. The suction port is a space formed axially along a crankshaft and allows the lower space below themain frame 2 and the upper space above the main frame to communicate with each other. The refrigerant flows into the shell through a suction pipe provided in a side portion of the shell and, while swirling around the axis of the crankshaft in the lower space below the main frame, flows into the compression chamber through the suction port provided in the main frame. -
- Patent Literature 1: Japanese Patent Application No. 2020-515425
-
[0005] In the scroll compressor disclosed inPatent Literature 1, the suction port formed in the main frame runs in the vertical direction relative to the direction in which the refrigerant swirls around the axis of the crankshaft. That is, the suction port is not formed along the flow of the refrigerant moving from the lower space below the main frame to the upper space above the main frame. Thus, in the scroll compressor, the refrigerant swirling in the lower space below the main frame is likely to receive resistance when flowing into the suction port, and pressure loss of the refrigerant may thereby be caused. In addition, if, with the increase in the rotational speed of the compressor, the circulation amount of the refrigerant is increased, and the flow rate of the refrigerant is increased, the pressure loss is further increased, thereby causing performance reduction. -
[0006] The present disclosure has been made to solve such an above-described problem, and an object thereof is to provide a scroll compressor enabling reduction of an increase in the pressure loss of refrigerant and enabling suppression of performance reduction, even if the circulation amount of the refrigerant is increased, and the flow rate of the refrigerant is increased. -
[0007] A scroll compressor according to an embodiment of the present disclosure includes: a shell forming a sealed space; a main frame fixed to an inner wall surface of the shell; a fixed scroll including a first base plate provided with a first scroll body; an orbiting scroll supported by the main frame so as to orbit around the fixed scroll, the orbiting scroll including a second base plate provided with a second scroll body meshing with the first scroll body, the orbiting scroll forming, with the fixed scroll, a compression chamber in which refrigerant is compressed; and a crankshaft transmitting rotational driving force to the orbiting scroll. The main frame has a suction port for supplying an inside of the compression chamber with refrigerant swirling around the crankshaft in a lower space below the main frame. The suction port is formed so as to be tilted relative to an axial direction of the crankshaft while running in a direction in which refrigerant flows from the lower space below the main frame to an upper space above the main frame. -
[0008] According to an embodiment of the present disclosure, because the suction port is formed so as to be tilted relative to the axial direction of the crankshaft while running in the direction in which the refrigerant flows, the resistance acting on the refrigerant can be reduced when the refrigerant swirling in the lower space below the main frame flows into the suction port. Thus, even if the circulation amount of the refrigerant is increased, and the flow rate of the refrigerant is increased, an increase in the pressure loss of the refrigerant can be reduced, and performance reduction can be suppressed. -
[0009] FIG. 1 is a vertical sectional view of the inner structure of a scroll compressor according to Embodiment. -
[0010] FIG. 2 is an exploded perspective view of a related part of the scroll compressor according to Embodiment. -
[0011] FIG. 3 is an enlarged view of part III inFIG. 1 . -
[0012] FIG. 4 illustrates the flows of refrigerant in the scroll compressor according to Embodiment. -
[0013] FIG. 5 schematically illustrates a suction port of a main frame of the scroll compressor according to Embodiment. -
[0014] FIG. 6 is a transverse sectional view of a compression mechanism unit of the scroll compressor according to Embodiment. -
[0015] FIG. 7 is a vertical sectional view of the inner structure of the scroll compressor according to Embodiment and an enlarged view of a related part in which the suction port is formed. -
[0016] FIG. 8 illustrates the main frame of the scroll compressor according to Embodiment when viewed from below. -
[0017] FIG. 9 illustrates the main frame of the scroll compressor according to Embodiment when viewed from below. -
[0018] FIG. 10 illustrates a modification of the scroll compressor according to Embodiment and is a transverse sectional view of the compression mechanism unit. -
[0019] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. Note that, in the drawings, the same or equivalent parts are denoted by the same references, and the description thereof will appropriately be omitted or simplified. In addition, for example, the shapes, the sizes, and the arrangement of the constituents illustrated in the drawings can appropriately be changed. -
[0020] FIG. 1 is a vertical sectional view of the inner structure of ascroll compressor 100 according to Embodiment.FIG. 2 is an exploded perspective view of a related part of thescroll compressor 100 according to Embodiment.FIG. 3 is an enlarged view of part III inFIG. 1 . Note that thescroll compressor 100, inFIG. 1 , according to Embodiment is a so-called vertical scroll compressor that is used with the central axis of acrankshaft 7 being substantially perpendicular to the ground. Thescroll compressor 100 is one of the constituting elements of a refrigeration cycle that is used for, for example, a refrigerator, a freezer, an air-conditioning apparatus, a refrigeration apparatus, or a water heater. -
[0021] Thescroll compressor 100 sucks the refrigerant circulating through the refrigeration cycle, compresses to bring the refrigerant into a high-temperature and high-pressure state, and discharges the refrigerant in such a state. AsFIGS. 1 and 2 illustrate, thescroll compressor 100 includes ashell 1 constituting an outer contour, amain frame 2 joined to an inner wall surface of theshell 1, acompression mechanism unit 3 that compresses refrigerant, adriving mechanism unit 6 that drives thecompression mechanism unit 3, and thecrankshaft 7 coupling thecompression mechanism unit 3 and thedriving mechanism unit 6 to each other. -
[0022] AsFIG. 1 illustrates, theshell 1 is constituted by a conductive part such as a metal. Theshell 1 has, thereinside, a sealed space formed by closing both ends of a tubular body. Themain frame 2, thecompression mechanism unit 3, thedriving mechanism unit 6, and thecrankshaft 7 are accommodated inside theshell 1. -
[0023] Theshell 1 includes amain shell 1 a having a cylindrical shape, anupper shell 1 b closing an upper-side opening of themain shell 1 a and having a substantially dome shape, and alower shell 1 c closing a lower-side opening of themain shell 1 a and having a substantially dome shape. A portion of a side wall of each of theupper shell 1 b and thelower shell 1 c is joined to themain shell 1 a by, for example, welding. Theshell 1 is supported by afixation base 1 d fixed to thelower shell 1 c. -
[0024] AsFIG. 2 illustrates, an inner wall surface of themain shell 1 a includes a firstinner wall surface 10 a formed in an upper end portion and having a large inside diameter, a secondinner wall surface 10 b formed below the firstinner wall surface 10 a and having an inside diameter smaller than the inside diameter of the firstinner wall surface 10 a, and a thirdinner wall surface 10 c formed below the secondinner wall surface 10 b and having an inside diameter smaller than the inside diameter of the secondinner wall surface 10 b. Afirst step part 11 a is formed by a lower end of the firstinner wall surface 10 a and an upper end of the secondinner wall surface 10 b and protrudes in the radial direction from the inner wall surface of theshell 1, and thefirst step part 11 a functions as a positioning part for afixed scroll 4. Asecond step part 11 b is formed by a lower end of the secondinner wall surface 10 b and an upper end of the thirdinner wall surface 10 c and protrudes in the radial direction from the inner wall surface of theshell 1, and thesecond step part 11 b functions as a positioning part for themain frame 2. -
[0025] AsFIG. 1 illustrates, themain shell 1 a is provided with asuction pipe 13 for introducing refrigerant into theshell 1 and apower supply unit 19 for supplying power to thescroll compressor 100. A portion of thesuction pipe 13 is inserted into a hole formed in a side wall of themain shell 1 a, and thesuction pipe 13 in such a state is connected to themain shell 1 a by, for example, welding. Thesuction pipe 13 communicates with the inner space of theshell 1. Thepower supply unit 19 includes acover 19 a, apower supply terminal 19 b, and awire 19 c. Thepower supply terminal 19 b is a metal part. One end thereof is disposed so as to be surrounded by thecover 19 a, and the other end thereof is disposed inside themain shell 1 a. One end of thewire 19 c is connected to thepower supply terminal 19 b, and the other end thereof is connected to thedriving mechanism unit 6. -
[0026] Adischarge pipe 14 for discharging the compressed refrigerant outside theshell 1 is connected to theupper shell 1 b. Thedischarge pipe 14 communicates with the inner space of theshell 1. A portion of thedischarge pipe 14 is inserted into a hole formed in an upper portion of theupper shell 1 b, and thedischarge pipe 14 in such a state is connected to theupper shell 1 b by, for example, welding. Anoil sump 18 for storing a lubricating oil is provided in an inner bottom portion of theshell 1. -
[0027] AsFIGS. 1 and 2 illustrate, themain frame 2 is a metal frame having a tubular shape tapered downward in a stepwise manner and supports anorbiting scroll 5 such that theorbiting scroll 5 orbits. With an outer peripheral wall of themain frame 2 being supported by thesecond step part 11 b of themain shell 1 a, the outer peripheral wall of themain frame 2 is fixed to the secondinner wall surface 10 b of themain shell 1 a by, for example, shrink fitting. Aflat surface 20 having an annular shape is formed in an upper surface of themain frame 2. Athrust plate 25 having a ring shape and made of a steel-plate material such as a valve steel is provided on theflat surface 20. Thethrust plate 25 functions as a thrust sliding surface of themain frame 2 and supports a thrust load of thecompression mechanism unit 3. -
[0028] In addition, asFIG. 2 illustrates, a tube inner part of themain frame 2 is constituted by anaccommodation part 21 and amain bearing part 22 supporting thecrankshaft 7. Theaccommodation part 21 is provided in an upper portion of themain frame 2. Themain bearing part 22 is provided in a lower portion of themain frame 2. -
[0029] AsFIG. 2 illustrates, theaccommodation part 21 is formed such that the inside diameter thereof decreases downward in a stepwise manner. In theaccommodation part 21, a step part positioned on theflat surface 20 side serves as anOldham accommodation part 21 a, and a step part positioned on themain bearing part 22 side serves as abush accommodation part 21 b. In addition, a pair offirst Oldham grooves 21 c is provided in portions of theOldham accommodation part 21 a and portions of theflat surface 20, and thefirst Oldham grooves 21 c are formed so as to face each other with a shaft hole interposed therebetween. Each of thefirst Oldham grooves 21 c is a key groove. A portion of thefirst Oldham groove 21 c overlaps thethrust plate 25 when themain frame 2 is viewed from above. -
[0030] In addition, themain frame 2 has asuction port 26 for supplying thecompression mechanism unit 3 with the refrigerant swirling around thecrankshaft 7 in the lower space below themain frame 2. Thesuction port 26 is formed in an outer edge portion of theflat surface 20 of themain frame 2 and passes through in an up-down direction such that the lower space below themain frame 2 and the upper space above themain frame 2 communicate with each other. Specifically, the outer peripheral wall of themain frame 2 has a recessedpart 27 allowing the lower space below themain frame 2 and the upper space above themain frame 2 to communicate with each other and formed circumferentially along themain frame 2. AsFIGS. 1 to 3 illustrate, thesuction port 26 is a space surrounded by the recessedpart 27 and the inner wall surface of theshell 1. In addition, thethrust plate 25 has, at a position corresponding to thesuction port 26 of themain frame 2, acutout part 25 a that is formed by cutting out a portion of the outer periphery of thethrust plate 25. Thecutout part 25 a has the same shape as thesuction port 26 or is formed larger than thesuction port 26 such that thesuction port 26 is not covered. -
[0031] In addition, asFIGS. 1 and 3 illustrate, in themain frame 2, anoil return pipe 24 is inserted into anoil return hole 23 passing through the inside of themain frame 2 to the outside of themain frame 2, and theoil return pipe 24 in such a state is fixed. Theoil return hole 23 communicates with thebush accommodation part 21 b. Theoil return pipe 24 is provided for returning the lubricating oil accumulated in theaccommodation part 21 to theoil sump 18 provided in thelower shell 1 c. Note that, regarding theoil return hole 23 and theoil return pipe 24, the number thereof is not limited to one and may be more than one. -
[0032] The above-describedmain frame 2 is made of an iron-based metal or an aluminum-based metal. Themain frame 2 is shaped by casting when formed by using an iron-based material. In addition, themain frame 2 is formed by machining when formed by using a carbon steel material for machine structures. Themain frame 2 is formed by casting or forging when an aluminum-based material is used. -
[0033] Thecompression mechanism unit 3 includes the fixedscroll 4 and theorbiting scroll 5. AsFIGS. 2 and 3 illustrate, the fixedscroll 4 includes afirst base plate 4 a having a disk shape and afirst scroll body 4 b provided on a lower surface of thefirst base plate 4 a. Theorbiting scroll 5 includes asecond base plate 5 a having a disk shape and asecond scroll body 5 b provided on an upper surface of thesecond base plate 5 a and meshing with thefirst scroll body 4 b. Theorbiting scroll 5 is mounted eccentrically to the fixedscroll 4. Thefirst scroll body 4 b of the fixedscroll 4 and thesecond scroll body 5 b of theorbiting scroll 5 are combined to form acompression chamber 30 in which refrigerant is compressed. -
[0034] The fixedscroll 4 is formed by a metal such as cast iron. The fixedscroll 4 is joined to the firstinner wall surface 10 a by, for example, shrink fitting, with an outer peripheral surface of thefirst base plate 4 a being supported by thefirst step part 11 a of themain shell 1 a. Note that the configuration in which the fixedscroll 4 is joined to the firstinner wall surface 10 a is not the only option, and the fixedscroll 4 may be, for example, screwed to themain frame 2. -
[0035] A center portion of thefirst base plate 4 a has adischarge port 40 through which the refrigerant that has been compressed into high-temperature and high-pressure refrigerant is discharged. Achamber 15 having adischarge hole 15 a communicating with thedischarge port 40 is provided on an upper surface of the fixedscroll 4. Adischarge valve 17 is screwed to thechamber 15, and thedischarge valve 17 opens and closes thedischarge hole 15 a according to the pressure of the refrigerant. Thedischarge valve 17 brings thedischarge hole 15 a into an open state when the pressure of the refrigerant in thecompression chamber 30, which communicates with thedischarge port 40, reaches a predetermined pressure. The compressed high-temperature and high-pressure refrigerant is sent out from thedischarge port 40 into a high-pressure space 16 positioned above the fixedscroll 4 and then passes through thedischarge pipe 14 to be discharged outside theshell 1. In addition, a distal end portion of thefirst scroll body 4 b has a groove, and atip seal 41 made of, for example, a hard plastic is provided for the groove. -
[0036] Theorbiting scroll 5 is formed by a metal such as aluminum. AsFIGS. 1 to 3 illustrate, with anOldham ring 54 for preventing theorbiting scroll 5 from rotating on its axis, theorbiting scroll 5 performs a revolving motion relative to the fixedscroll 4 without rotating on its axis. Note that a surface of thesecond base plate 5 a (a lower surface in the illustrated example) on the side where thesecond scroll body 5 b is not formed functions as an orbiting-scroll thrust bearing surface. In addition, aboss part 51 having a hollow cylindrical shape is provided at a center portion of the orbiting-scroll thrust bearing surface. An orbiting bearing for supporting aslider 80 of abush 8 such that theslider 80 rotates is provided in an inner peripheral surface of theboss part 51. The orbiting bearing is a so-called journal bearing. The orbiting bearing is provided such that the central axis thereof is parallel to the central axis of thecrankshaft 7. The rotation of aneccentric shaft part 71, of thecrankshaft 7, inserted into theboss part 51 causes theorbiting scroll 5 to perform a revolving motion on the thrust sliding surface of themain frame 2. -
[0037] In addition, a distal end portion of thesecond scroll body 5 b has a groove, and atip seal 52 made of, for example, a hard plastic is provided for the groove. In addition, the orbiting-scroll thrust bearing surface hassecond Oldham grooves 53 in a pair that are formed so as to face each other with theboss part 51 interposed therebetween. Each of thesecond Oldham grooves 53 is a key groove having an elliptical shape. The pairedsecond Oldham grooves 53 are disposed such that the line connecting thesecond Oldham grooves 53 to each other is orthogonal to the line connecting the pairedfirst Oldham grooves 21 c to each other. -
[0038] TheOldham ring 54 includes aring part 54 a, firstkey parts 54 b, and secondkey parts 54 c. Thering part 54 a has an annular shape and is accommodated in theOldham accommodation part 21 a of themain frame 2. The firstkey parts 54 b are provided on a lower surface of thering part 54 a. The firstkey parts 54 b are paired and accommodated in the respective pairedfirst Oldham grooves 21 c of themain frame 2. The secondkey parts 54 c are provided on an upper surface of thering part 54 a. The secondkey parts 54 c are paired and accommodated in the respective pairedsecond Oldham grooves 53 of theorbiting scroll 5. The position of thesecond scroll body 5 b of theorbiting scroll 5 in the rotation direction is determined by aligning thesecond Oldham grooves 53 of theorbiting scroll 5 with the secondkey parts 54 c of theOldham ring 54. That is, theorbiting scroll 5 is positioned, relative to themain frame 2, by theOldham ring 54, and the phase of thesecond scroll body 5 b relative to themain frame 2 is determined. When the rotation of thecrankshaft 7 causes theorbiting scroll 5 to revolve, the firstkey part 54 b slides in thefirst Oldham groove 21 c, and the secondkey part 54 c slides in thesecond Oldham groove 53; thus, theOldham ring 54 prevents theorbiting scroll 5 from rotating on its axis. -
[0039] Thecompression chamber 30 is formed by meshing thefirst scroll body 4 b of the fixedscroll 4 and thesecond scroll body 5 b of theorbiting scroll 5 with each other and by sealing with thetip seal 41, which is provided on the distal end of thefirst scroll body 4 b, and thesecond base plate 5 a and with thetip seal 52, which is provided on the distal end of thesecond scroll body 5 b, and thefirst base plate 4 a. Thecompression chamber 30 is constituted by plural compression chambers having volumes that are reduced from the outer side to the inner side in the radial direction of the scroll. -
[0040] The refrigerant is, for example, a halogenated hydrocarbon having double-bonded carbon in the composition, a halogenated hydrocarbon having no double-bonded carbon in the composition, a hydrocarbon, or a mixture including any one of these hydrocarbons. Examples of the halogenated hydrocarbon having double-bonded carbon include an HFC refrigerant having zero ozone depletion potential, and tetrafluoropropene such as HFO1234yf, HFO1234ze, or HFO1243zf that is a fluorocarbon-based refrigerant, with a low GWP, represented by a chemical formula C3H2F4. Examples of the halogenated hydrocarbon having no double-bonded carbon include a refrigerant mixed with, for example, R32 (difluoromethane) represented as CH2F2, or R41. Examples of the hydrocarbon include natural refrigerants such as propane and propylene. Examples of the mixture include mixed refrigerants of, for example, HFO1234yf, HFO1234ze, and HFO1243zf mixed with, for example, R32 or R41. -
[0041] AsFIG. 1 illustrates, thedriving mechanism unit 6 drives thecompression mechanism unit 3 coupled thereto by using thecrankshaft 7. Thedriving mechanism unit 6 is constituted by astator 6 a having an annular shape and supported by being joined to the inner wall surface of theshell 1 by, for example, shrink fitting and arotor 6 b attached so as to rotate while facing an inner surface of thestator 6 a. Thestator 6 a has a configuration in which, for example, an iron core formed by layering plural electromagnetic steel sheets is wound with a winding with an insulating layer interposed therebetween, and thestator 6 a has a ring shape in plan view. Therotor 6 b has a configuration in which a permanent magnet is provided inside an iron core formed by layering plural electromagnetic steel sheets, and therotor 6 b has, at the center, a through hole passing through in the up-down direction. Therotor 6 b is disposed with a predetermined gap being maintained between an outer peripheral surface of therotor 6 b and an inner peripheral surface of thestator 6 a. -
[0042] Thecrankshaft 7 is a rod-shaped metal part asFIG. 1 illustrates. Thecrankshaft 7 includes amain shaft part 70 and theeccentric shaft part 71. Themain shaft part 70 is a shaft constituting a main part of thecrankshaft 7 and is disposed such that the central axis thereof coincides with the central axis of themain shell 1 a. Themain shaft part 70 is fixed in the through hole positioned at the center of therotor 6 b by, for example, shrink fitting and is supported so as to rotate by themain bearing part 22 provided in a center portion of themain frame 2 and by asub-bearing part 90 provided in a center portion of asub-frame 9 joined to a lower portion of theshell 1 by, for example, welding or shrink fitting. -
[0043] AsFIGS. 1 to 3 illustrate, theeccentric shaft part 71 is provided on an upper end portion of themain shaft part 70 such that the central axis thereof is eccentric to the central axis of themain shaft part 70. Theeccentric shaft part 71 is connected to theorbiting scroll 5 with thebush 8 that is a part of a metal, such as iron, interposed therebetween, and theeccentric shaft part 71 is supported by theboss part 51 of theorbiting scroll 5 so as to rotate. Thecrankshaft 7 rotates with the rotation of therotor 6 b, and theeccentric shaft part 71 of thecrankshaft 7 causes theorbiting scroll 5 to revolve. In addition, inside each of themain shaft part 70 and theeccentric shaft part 71, anoil passage 72 is provided and vertically passes through in the axial direction. -
[0044] AsFIGS. 2 and 3 illustrate, thebush 8 includes theslider 80 and abalance weight 81. Theslider 80 is a tubular part on which a collar is formed and is inserted into theboss part 51 so as to rotate. Theeccentric shaft part 71 is inserted along a slide surface of theslider 80. That is, theslider 80 is interposed between the orbitingscroll 5 and theeccentric shaft part 71, and theslider 80 makes the radius of orbit of theorbiting scroll 5 variable and supports theorbiting scroll 5 such that theorbiting scroll 5 performs a revolving motion. -
[0045] Thebalance weight 81 is provided for cancelling the centrifugal force of theorbiting scroll 5 generated by an orbital motion. Thebalance weight 81 is provided eccentrically to the center of rotation. Thebalance weight 81 has a lower portion having an annular shape and an upper portion in which aweight part 81 a having a substantially C shape is provided on the side opposite to the direction of the centrifugal force exerted on theorbiting scroll 5. Thescroll compressor 100, with thebalance weight 81, can suppress thesecond scroll body 5 b from being pressed against thefirst scroll body 4 b. For example, thebalance weight 81 is fitted onto the collar of theslider 80 by, for example, shrink fitting. -
[0046] Thesub-frame 9 is a metal frame. AsFIG. 1 illustrates, thesub-frame 9 is provided with thesub-bearing part 90 and anoil pump 91. Thesub-bearing part 90 is a ball bearing provided at the center of thesub-frame 9. Theoil pump 91 is a pump for pumping up the lubricating oil stored in theoil sump 18 of theshell 1 and is provided below thesub-bearing part 90. Theoil pump 91 is disposed such that at least a portion thereof is immersed in the lubricating oil. -
[0047] The lubricating oil is stored in theoil sump 18. The lubricating oil is pumped up by theoil pump 91 and passes through theoil passage 72 of thecrankshaft 7, thereby reducing wear between, for example, parts of thecompression mechanism unit 3 that come into mechanical contact with each other, adjusting the temperature of a sliding part, and improving the sealing performance. For the lubricating oil, there is preferably used an oil that is good in lubricate characteristics, electrical insulation property, stability, refrigerant solubility, and fluidity at low temperature and has a moderate viscosity. For the lubricating oil, there may be used oils such as a naphthene-based oil and oils of polyolester (POE), polyvinyl ether (PVE), and polyalkylene glycol (PAG). -
[0048] Next, while referring toFIGS. 1 to 3 , the features of thesuction port 26 of themain frame 2 will be described with reference toFIGS. 4 to 9 .FIG. 4 illustrates the flows of the refrigerant in thescroll compressor 100 according to Embodiment.FIG. 5 schematically illustrates thesuction port 26 of themain frame 2 of thescroll compressor 100 according to Embodiment.FIG. 6 is a transverse sectional view of thecompression mechanism unit 3 of thescroll compressor 100 according to Embodiment.FIG. 7 is a vertical sectional view of the inner structure of thescroll compressor 100 according to Embodiment and an enlarged view of a related part in which thesuction port 26 is formed.FIG. 8 illustrates themain frame 2 of thescroll compressor 100 according to Embodiment when viewed from below.FIG. 9 illustrates themain frame 2 of thescroll compressor 100 according to Embodiment when viewed from below. Note that, inFIG. 4 , the black arrows indicate the directions where the refrigerant flows, and the hollow arrow indicates the rotation direction of thecrankshaft 7. In addition, inFIG. 5 , only the features of Embodiment are given, and other constituting elements are omitted. -
[0049] As the black arrows illustrated inFIG. 4 indicate, the refrigerant flows into theshell 1 through thesuction pipe 13 provided in a side portion of theshell 1 and, while swirling around thecrankshaft 7 in the lower space below themain frame 2, flows into thecompression chamber 30 through thesuction port 26 provided in themain frame 2. Note that the refrigerant that has flowed into theshell 1 through thesuction pipe 13 is sometimes divided into portions flowing clockwise and flowing counterclockwise around theboss part 51; however, after that, only the flow in a swirling direction, which is the same as the rotation direction of the crankshaft 7 (the hollow arrow inFIG. 4 ) remains, and the refrigerant swirls in one direction, that is, the rotation direction of the crankshaft 7 (the hollow arrow inFIG. 4 ). That is, even if thescroll compressor 100 is started over and over, the swirling direction of the refrigerant is determined according to the rotation direction of thecrankshaft 7. -
[0050] In the case of thescroll compressor 100 in which thesuction port 26 formed in themain frame 2 runs in the vertical direction relative to the direction in which the refrigerant swirls around the axis of thecrankshaft 7, when the refrigerant swirling in the lower space below themain frame 2 flows into thesuction port 26, the refrigerant is likely to receive resistance, and the pressure loss of the refrigerant is thus caused. In addition, if, with the increase in the speed of the rotation of thescroll compressor 100, the circulation amount of the refrigerant is increased, and the flow rate of the refrigerant is increased, the pressure loss is further increased, and performance reduction may thereby be caused. -
[0051] Thus, asFIG. 5 illustrates, thesuction port 26 of thescroll compressor 100 according to Embodiment is formed so as to be tilted relative to the axial direction of thecrankshaft 7 while running in the direction in which the refrigerant flows. That is, thesuction port 26 is formed so as to be tilted according to the rotation direction of thecrankshaft 7. Thus, the positions of aninlet 26 a and anoutlet 26 b of thesuction port 26 are displaced in the circumferential direction of themain frame 2. A greater tilt angle of thesuction port 26 is preferable because thesuction port 26 can be made more parallel to the direction in which the refrigerant flows; however, the tilt angle is limited due to the structure of themain frame 2, the shape of a hole of thesuction port 26, and the size and the installation position of thesuction port 26, for example. Thus, the tilt angle of thesuction port 26 is set in consideration of the above-described limitations. -
[0052] In addition, asFIG. 6 illustrates, twosuction ports 26 are provided so as to face each other in the radial direction of themain frame 2. Theoutlet 26 b of onesuction port 26 is formed at a position apart from anouter end portion 4 c of thefirst scroll body 4 b, with an intersection point O1 of a line X1 extended from theouter end portion 4 c of thefirst scroll body 4 b (a winding end portion) toward an outer peripheral edge of themain frame 2 and the outer peripheral edge of themain frame 2 as an origin. Theoutlet 26 b of theother suction port 26 is formed at a position apart from anouter end portion 5 c of thesecond scroll body 5 b, with an intersection point O2 of a line X2 extended from theouter end portion 5 c of thesecond scroll body 5 b (a winding end portion) toward the outer peripheral edge of themain frame 2 and the outer peripheral edge of themain frame 2 as an origin. -
[0053] The recessedpart 27 constituting thesuction port 26 is formed, as a twisted groove, in an outer wall surface of themain frame 2. Thus, the action of the centrifugal force causes the refrigerant that has been introduced into thesuction port 26 to flow along the inner wall surface of theshell 1. At this point, if theoutlet 26 b of thesuction port 26 is disposed close to theouter end portion 4 c of thefirst scroll body 4 b or theouter end portion 5 c of thesecond scroll body 5 b, the refrigerant that has flowed out from thesuction port 26 flows outside thefirst scroll body 4 b or thesecond scroll body 5 b, along the inner wall surface of theshell 1, and the refrigerant is not thereby successfully introduced into the vortex of thefirst scroll body 4 b or thesecond scroll body 5 b. -
[0054] Thus, as described above, theoutlet 26 b of thesuction port 26 is preferably positioned at a certain distance from theouter end portion 4 c of thefirst scroll body 4 b or theouter end portion 5 c of thesecond scroll body 5 b, by being disposed at the position illustrated inFIG. 6 . This arrangement can suppress the refrigerant that has flowed out from thesuction port 26 from flowing outside thefirst scroll body 4 b or thesecond scroll body 5 b, and the refrigerant can be introduced efficiently into the vortex of thefirst scroll body 4 b or thesecond scroll body 5 b. However, theoutlet 26 b of thesuction port 26 from which the refrigerant is introduced into theouter end portion 4 c of thefirst scroll body 4 b is provided at a position closer to theouter end portion 4 c of thefirst scroll body 4 b than to theouter end portion 5 c of thesecond scroll body 5 b. Similarly, theoutlet 26 b of thesuction port 26 from which the refrigerant is introduced into theouter end portion 5 c of thesecond scroll body 5 b is provided at a position closer to theouter end portion 5 c of thesecond scroll body 5 b than to theouter end portion 4 c of thefirst scroll body 4 b. -
[0055] Note that, theoutlet 26 b of thesuction port 26 is preferably provided at a position where, when thecrankshaft 7 makes one rotation to cause theorbiting scroll 5 to orbit, thesuction port 26 and thesecond scroll body 5 b do not overlap each other due to the orbital motion. If theoutlet 26 b of thesuction port 26 and thesecond scroll body 5 b overlap each other, at this moment, the pressure loss due to reduction of the opening area of theoutlet 26 b is caused. -
[0056] In addition, asFIG. 7 illustrates, theshell 1 has thesecond step part 11 b protruding from the inner wall surface in the radial direction and supporting the outer peripheral wall of themain frame 2. Thus, when a space surrounded by the recessedpart 27 formed in the outer peripheral wall of themain frame 2 and the inner wall surface of theshell 1 serves as thesuction port 26, the opening area of theinlet 26 a through which the refrigerant passes is smaller than the opening area of theoutlet 26 b by a dimension of thesecond step part 11 b. When the opening area of theinlet 26 a through which the refrigerant passes is smaller than the opening area of theoutlet 26 b, the speed of the refrigerant at a position close to theoutlet 26 b is slightly decreased, and the pressure loss at theinlet 26 a is increased relative to theoutlet 26 b. Thus, theinlet 26 a of thesuction port 26 is formed larger than theoutlet 26 b of thesuction port 26 in the radial direction by the dimension of thesecond step part 11 b protruding in the radial direction. At this point, an inner surface of the recessedpart 27 is tilted to the outside diameter side while running from theinlet 26 a toward theoutlet 26 b. Thus, the opening area of theinlet 26 a of thesuction port 26 and the opening area of theoutlet 26 b of thesuction port 26 can be made substantially equal, and the pressure loss at theinlet 26 a can thereby be suppressed. Note that the opening area of theinlet 26 a of thesuction port 26 and the opening area of theoutlet 26 b of thesuction port 26 may differ if there is no particular problem of, for example, pressure loss. -
[0057] In addition, asFIG. 8 illustrates, the twosuction ports 26 may be amain port 260 and a sub-port 261 having an opening area smaller than themain port 260. The opening areas of thesuction ports 26 differ because the amount of the opening area may be limited due to the arrangement relationship of a stiffeningrib 28 provided for themain frame 2, thesuction pipe 13 connected to theshell 1, and other parts. In this case, the sub-port 261 is preferably formed at a position closer to thesuction pipe 13 than themain port 260. Moreover, asFIG. 9 illustrates, themain port 260 is preferably formed at a position where themain port 260 faces thesuction pipe 13 with themain bearing part 22 interposed therebetween. The sub-port 261 is most suitably formed circumferentially along themain frame 2, at a position midway between themain port 260 and themain bearing part 22. As described above, due to positioning the sub-port 261 close to thesuction pipe 13, the refrigerant easily flows into and through the sub-port 261, and the refrigerant introduction amounts of thefirst scroll body 4 b and thesecond scroll body 5 b can be made similar to each other. -
[0058] That is, the hole shapes and the sizes of theinlet 26 a and theoutlet 26 b of thesuction port 26 may be the same or may differ. In addition, in consideration of the structure of the lower portion of themain frame 2, theinlet 26 a and theoutlet 26 b of thesuction port 26 may be displaced in the radial direction of themain frame 2 such that, for example, theinlet 26 a is positioned on the inside diameter side or the outside diameter side of themain frame 2, and theoutlet 26 b is positioned on the outside diameter side or the inside diameter side. -
[0059] In addition, the resistance generated when the refrigerant flows into thesuction port 26 is reduced by tilting thesuction port 26, and the flow rate of the refrigerant swirling in the lower space below themain frame 2 is thereby increased; thus, the amount of the refrigerating machine oil that is introduced into thecompression chamber 30 with the refrigerant may be increased. Thus, asFIG. 5 illustrates, aninner wall surface 26 c of thesuction port 26 has a fine uneven shape, and the surface roughness of theinner wall surface 26 c of thesuction port 26 is preferably made moderately great. The surface roughness of the inner wall of thesuction port 26 is greater than or equal to, for example, the surface roughness of an unprocessed casting surface in the case of casting or the surface roughness of a surface finished by medium-grade machining in the case of machining. By doing in the above-described ways, the refrigerating machine oil introduced into thecompression chamber 30, with the refrigerant, sticks to the fine uneven surface of the inner wall of thesuction port 26, and the amount of the introduced refrigerating machine oil can be suppressed from increasing. -
[0060] When injection refrigerant is injected into thecompression chamber 30, an inflow port for injection is provided, in thefirst base plate 4 a of the fixedscroll 4, at a position corresponding to a part A inFIG. 6 , and the injection refrigerant, with the refrigerant flowing in from thesuction port 26, can thereby be efficiently introduced into the vortex. -
[0061] Note thatFIG. 10 illustrates a modification of thescroll compressor 100 according to Embodiment and is a transverse sectional view of thecompression mechanism unit 3. Thesuction port 26 is not limited to the configurations illustrated inFIGS. 1 to 9 . AsFIG. 10 illustrates, thesuction port 26 may be formed, in an outer edge portion of theflat surface 20 of themain frame 2, as a through hole passing through in the up-down direction such that the lower space below themain frame 2 and the upper space above themain frame 2 communicate with each other. -
[0062] In this case, theoutlet 26 b of each of thesuction ports 26 is positioned so as to face an introduction position B of the refrigerant that is introduced into thecompression chamber 30. Two positions B where the refrigerant that has flowed into the upper space above themain frame 2 from theoutlet 26 b is introduced into thecompression chamber 30 are provided at theouter end portion 5 c (the winding end portion) of thesecond scroll body 5 b of theorbiting scroll 5 and at theouter end portion 4 c (the winding end portion) of thefirst scroll body 4 b of the fixedscroll 4. Theoutlet 26 b of thesuction port 26 is provided so as to face the introduction position A of the refrigerant that is introduced into thecompression chamber 30, and the refrigerant that has flowed out from thesuction port 26 is thereby introduced into thecompression chamber 30 at the shortest distance; thus, the resistance acting on the refrigerant can be suppressed from increasing. Note that thesuction port 26 of Embodiment has an elliptical shape in plan view in one example. The major axis direction of the ellipse may be the same as a tangential direction of the outer periphery of themain frame 2, and the extension line of the major axis may extend through the position A where the refrigerant is introduced into thecompression chamber 30. Moreover, theoutlet 26 b of thesuction port 26 may be provided at a position where, when one rotation of thecrankshaft 7 causes theorbiting scroll 5 to orbit, thesuction port 26 and thesecond scroll body 5 b do not overlap each other due to the orbital motion. This is because, when theoutlet 26 b of thesuction port 26 and thesecond scroll body 5 b overlap each other, at this moment, the pressure loss is generated by reducing the opening area. -
[0063] In addition, the hole shapes and the sizes of theinlet 26 a and theoutlet 26 b of thesuction port 26 illustrated inFIG. 10 may be the same or may differ. In addition, in consideration of the structure of the lower portion of themain frame 2, in thesuction port 26, theinlet 26 a and theoutlet 26 b may be displaced in the radial direction of themain frame 2 such that, for example, theinlet 26 a is positioned on the inside diameter side or the outside diameter side of themain frame 2, and theoutlet 26 b is positioned on the outside diameter side or the inside diameter side. In addition, asFIG. 5 illustrates, theinner wall surface 26 c of thesuction port 26 may have a fine uneven shape, and the surface roughness of theinner wall surface 26 c of thesuction port 26 may be made moderately great. -
[0064] As described above, thescroll compressor 100 according to Embodiment includes: theshell 1 forming a sealed space; themain frame 2 fixed to the inner wall surface of theshell 1; the fixedscroll 4 including thefirst base plate 4 a provided with thefirst scroll body 4 b; theorbiting scroll 5 supported by themain frame 2 so as to orbit around the fixed scroll, theorbiting scroll 5 including thesecond base plate 5 a provided with thesecond scroll body 5 b meshing with thefirst scroll body 4 b, theorbiting scroll 5 forming, between the orbitingscroll 5 and the fixedscroll 4, thecompression chamber 30 in which refrigerant is compressed; and thecrankshaft 7 transmitting rotational driving force to theorbiting scroll 5. Themain frame 2 has thesuction port 26 for supplying the inside of thecompression chamber 30 with the refrigerant swirling around thecrankshaft 7 in the lower space below themain frame 2. Thesuction port 26 is formed so as to be tilted relative to the axial direction of thecrankshaft 7 while running in the direction in which refrigerant flows from the lower space below themain frame 2 to the upper space above themain frame 2. -
[0065] Because, thesuction port 26 in thescroll compressor 100 according to Embodiment is formed so as to be tilted relative to the axial direction of thecrankshaft 7 while running in the direction in which the refrigerant flows, that is, the direction in which the refrigerant swirls around the axis of thecrankshaft 7, the resistance acting on the refrigerant can be reduced when the refrigerant swirling in the lower space below themain frame 2 flows into thesuction port 26. Thus, even if the circulation amount of the refrigerant is increased, and the flow rate of the refrigerant is increased, an increase in the pressure loss of the refrigerant can be reduced, and performance reduction can be suppressed. -
[0066] In addition, theoutlet 26 b of thesuction port 26 is formed at one or both of the position apart from theouter end portion 4 c of thefirst scroll body 4 b, with the intersection point O1 of the line X1 extended from theouter end portion 4 c of thefirst scroll body 4 b toward the outer peripheral edge of themain frame 2 and the outer peripheral edge of themain frame 2 as an origin, and the position apart from theouter end portion 5 c of thesecond scroll body 5 b, with the intersection point O2 of the line X2 extended from theouter end portion 5 c of thesecond scroll body 5 b toward the outer peripheral edge of themain frame 2 and the outer peripheral edge of themain frame 2 as an origin. Thus, theoutlet 26 b of thesuction port 26 can be positioned at a certain distance from theouter end portion 4 c of thefirst scroll body 4 b or theouter end portion 5 c of thesecond scroll body 5 b. Thus, in thescroll compressor 100, the refrigerant that has flowed out from thesuction port 26 can be suppressed from flowing outside thefirst scroll body 4 b or thesecond scroll body 5 b and can be introduced efficiently into the vortex of thefirst scroll body 4 b or thesecond scroll body 5 b. -
[0067] Thesuction ports 26 include themain port 260 and the sub-port 261 having an opening area smaller than themain port 260. Thus, it is possible to handle the case where the amount of the opening area of thesuction port 26 is limited due to the arrangement relationship of the stiffeningrib 28 provided for themain frame 2, thesuction pipe 13 connected to theshell 1, and other parts. -
[0068] Thescroll compressor 100 according to Embodiment further includes thesuction pipe 13 that is connected to theshell 1 and through which refrigerant is sucked inside from outside theshell 1. The sub-port 261 is formed at a position closer to thesuction pipe 13 than themain port 260. That is, due to positioning the sub-port 261 close to thesuction pipe 13, the refrigerant easily flows into and through the sub-port 261, and the refrigerant introduction amounts at thefirst scroll body 4 b and thesecond scroll body 5 b can be made similar to each other. -
[0069] In addition, themain frame 2 includes, in the center portion thereof, themain bearing part 22 supporting thecrankshaft 7. Themain port 260 is formed at a position where themain port 260 faces thesuction pipe 13 with themain bearing part 22 interposed therebetween. The sub-port 261 is formed circumferentially along themain frame 2, at a position midway between themain port 260 and themain bearing part 22. That is, due to positioning the sub-port 261 close to thesuction pipe 13, the refrigerant easily flows into and through the sub-port 261, and the refrigerant introduction amounts at thefirst scroll body 4 b and thesecond scroll body 5 b can be made similar to each other. -
[0070] Theshell 1 has thesecond step part 11 b protruding from the inner wall surface in the radial direction and supporting themain frame 2. Theinlet 26 a of thesuction port 26 is formed larger than theoutlet 26 b of thesuction port 26 in the radial direction by the dimension of thesecond step part 11 b protruding in the radial direction. Although thescroll compressor 100 according to Embodiment includes thesecond step part 11 b, the opening area of theinlet 26 a of thesuction port 26 and the opening area of theoutlet 26 b of thesuction port 26 can be made substantially equal, and the pressure loss at theinlet 26 a can thereby be suppressed from increasing. -
[0071] Theinner wall surface 26 c of thesuction port 26 has a fine uneven shape. Thus, the refrigerating machine oil introduced into thecompression chamber 30 with the refrigerant sticks to the fine uneven surface of the inner wall of thesuction port 26, and the amount of the introduced refrigerating machine oil can be suppressed from increasing. -
[0072] Although having so far been described above based on Embodiment, thescroll compressor 100 is not limited to the configurations of Embodiment described above. For example, the illustrated inner configuration of thescroll compressor 100 is not limited to the above-described content and may include another constituting element. In addition, thesuction ports 26 are not limited to the illustrated two suction ports, and onesuction port 26 or three ormore suction ports 26 may be provided. In short, thescroll compressor 100 encompasses a range of design changes and application variations usually made by those who skilled in the art without departing from the technical ideas of thescroll compressor 100.