Scroll compressor

Abstract

The present invention provides a scroll compressor comprising a sealed container and a compression mechanism provided inside the sealed container, the compression mechanism including a compression chamber and a refrigerant suction chamber formed therein, the refrigerant suction chamber being provided upstream of the compression chamber in the direction of refrigerant flow. The compression mechanism comprises: a fixed scroll including a fixed base plate having a discharge opening formed therein, a refrigerant in the compression chamber flowing into the discharge opening, and a fixed scroll wrap provided on one surface of the fixed base plate; and an orbiting scroll having an orbiting base plate facing an edge of the fixed scroll wrap and an orbiting scroll wrap provided on one surface of the orbiting base plate so as to mesh with the fixed scroll wrap, thereby forming a first compression chamber and a second compression chamber in a gap to the fixed scroll wrap. A first lower surface portion is formed on the surface of the fixed base plate on the side on which the fixed scroll wrap is provided, a second lower surface portion is formed on the surface of the orbiting base plate on the side on which the orbiting scroll wrap is provided. The first lower surface portion is disposed outside with respect to the outward-facing surface of the orbiting scroll wrap at the time of completion of refrigerant intake and is formed to communicate with the first compression chamber during the refrigerant suction process. The second lower surface portion is disposed outside with respect to the outward-facing surface of the fixed scroll wrap at the time of completion of the refrigerant intake and is formed to communicate with the second compression chamber during the refrigerant suction process.

Description

Scroll Compressor

[0001] The present disclosure relates to a scroll compressor having an orbiting scroll and a fixed scroll.

[0002] A scroll compressor is disclosed that includes an orbiting scroll and a fixed scroll, each of which has a circular base plate and spiral-shaped teeth (hereinafter referred to as "volutes") (see, for example, Patent Document 1). In the scroll compressor of Patent Document 1, refrigerant is drawn into a shell from a suction pipe through a suction port formed in a frame and taken into a compression mechanism that includes an orbiting scroll and a fixed scroll. As the orbiting scroll orbits, refrigerant is drawn into the spaces between the orbiting scrolls through a suction passage at the end of each volute. The orbiting motion of the orbiting scroll then closes the suction passage, forming a compression chamber. The volume of the compression chamber is reduced, compressing the refrigerant.

[0003] In such scroll compressors, with the prospect of using low-density refrigerants such as R290, there is a demand for compressors with larger capacity and higher rotation speeds to achieve performance comparable to that of compressors using high-density refrigerants. Therefore, it is expected that the amount of refrigerant circulated in scroll compressors (i.e., the flow rate and flow velocity) will increase in the future.

[0004] Japanese Patent Application Publication No. 4-350383

[0005] However, in the scroll compressor described in Patent Document 1, the suction passage serving as the inlet to the compression chamber is limited to a suction passage with a rectangular cross section, surrounded by the scroll and base plate of the orbiting scroll at the end of the scroll and the scroll and base plate of the fixed scroll. Therefore, when an attempt is made to increase the refrigerant circulation rate, the cross-sectional area of ​​the suction passage is small relative to the refrigerant circulation rate, which increases flow resistance and increases suction pressure loss, resulting in performance degradation.

[0006] The present disclosure has been made against the background of the above-mentioned problems, and provides a scroll compressor with improved performance by reducing suction pressure loss by increasing the cross-sectional area of ​​the suction path to the compression chamber more than before.

[0007] The scroll compressor according to the present disclosure includes a compression mechanism provided within the sealed container, which includes a compression chamber and a refrigerant suction chamber provided upstream of the compression chamber in a refrigerant flow direction, the compression mechanism including a fixed scroll having a fixed base plate having a discharge port through which the refrigerant from the compression chamber flows and a fixed spiral provided on one surface of the fixed base plate, a swinging base plate facing the tip of the fixed spiral, and a swinging spiral provided on one surface of the swinging base plate so as to mesh with the fixed spiral and forming a first compression chamber and a second compression chamber between the fixed spiral and the swinging base plate. and an oscillating scroll having a first lower surface formed on the surface of the fixed base plate on which the fixed spiral is provided, and a second lower surface formed on the surface of the oscillating base plate on which the oscillating spiral is provided, the first lower surface being positioned outside the outward surface of the oscillating spiral when the refrigerant intake is completed and being formed to communicate with the first compression chamber during the refrigerant intake process, and the second lower surface being positioned outside the outward surface of the fixed spiral when the refrigerant intake is completed and being formed to communicate with the second compression chamber during the refrigerant intake process.

[0008] According to the present disclosure, the first and second low-surface portions increase the cross-sectional area of ​​the suction path to each compression chamber. Furthermore, because the first and second low-surface portions are positioned outward of the outward-facing surfaces of the opposing spirals when refrigerant intake is complete, the provision of the first and second low-surface portions does not widen the leakage flow path between the tip end surfaces of the spirals and the opposing base plate, thereby suppressing refrigerant leakage from the first and second low-surface portions after intake is complete. Therefore, by increasing the cross-sectional area of ​​the suction path to the compression chambers compared to conventional methods while keeping the refrigerant leakage flow path at a conventional size, suction pressure loss can be reduced, resulting in improved performance.

[0009] 1 is a longitudinal sectional view schematically showing the internal configuration of a scroll compressor 100 according to a first embodiment. FIG. 1 is a cross sectional view of the A-A section of the fixed scroll 1 and the orbiting scroll 2 of FIG. 1, viewed from below. FIG. 2 is a partial longitudinal sectional view schematically showing the peripheral portion of the compression mechanism in the scroll compressor 100 according to the first embodiment. FIG. 1 is a longitudinal sectional view showing the schematic configuration of the fixed scroll 1 of FIG. 1. FIG. 1 is a schematic view of the fixed scroll 1 of FIG. 1, viewed from below. FIG. 1 is a longitudinal sectional view showing the schematic configuration of the orbiting scroll 2 of FIG. 1. FIG. 1 is a schematic view of the orbiting scroll 2 of FIG. 1, viewed from above. FIG. 2 is a cross sectional view showing refrigerant suction paths 41, 42 to the compression chambers 30 in the fixed scroll 1 and the orbiting scroll 2 of FIG. 2. FIG. 8 is a longitudinal sectional view showing the B-B section of the fixed scroll 1 and the orbiting scroll 2 of FIG. 8. FIG. 9 is a longitudinal sectional view showing the C-C section of the fixed scroll 1 and the orbiting scroll 2 of FIG. 8. 13 is a diagram showing the positional relationship between the path expansion groove 1br and the end point 2af of the orbiting scroll 2a and the positional relationship between the path expansion notch 2br and the end point 1af of the fixed scroll 1a when the rotation phase of the orbiting scroll 2 in FIG. 8 is 0 [rad] (2π [rad]). 14 is a longitudinal sectional view showing the D-D section of the fixed scroll 1 and the orbiting scroll 2 in FIG. 11. 15 is a longitudinal sectional view showing the E-E section of the fixed scroll 1 and the orbiting scroll 2 in FIG. 11. 16 is a partial enlarged view of a portion Q1 in FIG. 12. 17 is a partial enlarged view of a portion Q2 in FIG. 13. 18 is an explanatory diagram illustrating the pressure difference between the two compression chambers in FIG. 11. 19 is a longitudinal sectional view showing a first modified example of the path expansion notch 2br in the orbiting scroll 2 in FIG. 6. 20 is a longitudinal sectional view showing a second modified example of the path expansion notch 2br in the orbiting scroll 2 in FIG. 6. 21 is a schematic view of the orbiting scroll 102 of the scroll compressor 100A according to a second embodiment, as viewed from above. FIG. 10 is a schematic view of a fixed scroll 101 of a scroll compressor 100A according to a second embodiment, viewed from below.

[0010] Embodiments of a scroll compressor according to the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to the following embodiments and may be modified in various ways without departing from the spirit and scope of the present disclosure. Furthermore, the present disclosure includes all possible combinations of the configurations shown in the following embodiments. In particular, the combinations of components are not limited to those in the respective embodiments; components described in one embodiment may be applied to another embodiment. The scroll compressors shown in the drawings are merely examples of devices to which the scroll compressors of the present disclosure can be applied, and the scroll compressors shown in the drawings do not limit the devices to which the present disclosure can be applied. In the following description, directional terms (e.g., "up," "down," "right," "left," "front," "rear," etc.) are used as appropriate to facilitate understanding. However, these terms are for illustrative purposes only and do not limit the present disclosure. In the drawings, components designated with the same reference numerals are identical or equivalent, and this applies throughout the entire specification. The relative dimensions or shapes of components in the drawings may differ from those in the actual devices.

[0011] Embodiment 1. FIG. 1 is a vertical cross-sectional view schematically illustrating the internal configuration of a scroll compressor 100 according to Embodiment 1. In FIG. 1, the flow of refrigerant is indicated by outline arrows. FIG. 2 is a horizontal cross-sectional view of the fixed scroll 1 and the orbiting scroll 2 of FIG. 1, taken along the line A-A, as viewed from below. For ease of explanation, FIG. 2 also illustrates the positions of two suction ports 26 formed in the frame 20. In addition, FIG. 2 indicates by dashed lines the oscillating base plate 2b and its path-extension notch 2br, which are located below the line A-A in FIG. 1. FIG. 3 is a partial vertical cross-sectional view schematically illustrating the compression mechanism and its peripheral portion in the scroll compressor 100 according to Embodiment 1. In FIG. 3, the thrust direction is indicated by outline arrows.

[0012] The configuration and operation of a scroll compressor 100 will be described with reference to Figures 1 to 3. The scroll compressor 100 is one of the components of a refrigeration cycle used in various industrial machines, such as refrigerators, freezers, vending machines, air conditioners, refrigeration systems, and water heaters.

[0013] 1, the scroll compressor 100 draws in refrigerant circulating through a refrigeration cycle, compresses it, and discharges it in a high-temperature, high-pressure state. The scroll compressor 100 has a compression mechanism that combines a fixed scroll 1 and an orbiting scroll 2 that orbits relative to the fixed scroll 1, mounted in a sealed container 22 that is composed of a center shell 22a, an upper shell 22b, and a lower shell (not shown). The scroll compressor 100 also has a rotary drive means, such as an electric rotating machine, mounted in the sealed container 22. The compression mechanism is located on the upper side of the sealed container 22, and the rotary drive means is located on the lower side.

[0014] The sealed container 22 is configured with an upper shell 22b above a center shell 22a and a lower shell (not shown) below the center shell 22a. The lower shell (not shown) serves as an oil reservoir for storing lubricating oil. The center shell 22a is connected to a suction pipe 15 for taking in refrigerant gas from the refrigerant circuit. The upper shell 22b is connected to the refrigerant circuit and is connected to a discharge pipe 17 for discharging refrigerant gas into the refrigerant circuit. As shown in FIGS. 1 and 3 , the interior of the center shell 22a forms a low-pressure chamber 18, and the interior of the upper shell 22b forms a high-pressure chamber 19.

[0015] As shown in FIG. 1 , the fixed scroll 1 is composed of a fixed base plate 1 b and a fixed spiral 1 a, which is a spiral protrusion formed on one surface of the fixed base plate 1 b. The orbiting scroll 2 is composed of a swing base plate 2 b and a swing spiral 2 a, which is a spiral protrusion formed on one surface of the swing base plate 2 b and has substantially the same shape as the fixed spiral 1 a and is formed to mesh with the fixed spiral 1 a. As shown in FIGS. 1 and 2 , the orbiting scroll 2 and the fixed scroll 1 are housed in a frame 20 having two suction ports 26. The other surface of the swing base plate 2 b (the surface (back surface) opposite to the surface on which the orbiting spiral 2 a is formed) serves as a thrust bearing surface 2 c. An Oldham groove 2 co is formed in the thrust bearing surface 2 c of the orbiting scroll 2. Details of the structures of the fixed scroll 1 and the orbiting scroll 2 will be described later.

[0016] 1 and 3, the orbiting scroll 2 is configured so that the thrust bearing load generated during operation of the scroll compressor 100 is supported by the frame 20 via the thrust bearing surface 2c. If the frame 20 does not have sufficient hardness to withstand the thrust bearing load, a thrust plate (not shown) made of a material having sufficient hardness to withstand the thrust bearing load may be inserted between the thrust bearing surface 2c and the frame 20.

[0017] As shown in Fig. 3, the orbiting scroll 2 and the fixed scroll 1 are mounted in a sealed container 22 with the orbiting spiral 2a and the fixed spiral 1a combined with each other. As shown in Fig. 2, when the orbiting scroll 2 and the fixed scroll 1 are combined, the winding directions of the fixed spiral 1a and the orbiting spiral 2a are opposite to each other. Between the orbiting spiral 2a and the fixed spiral 1a, compression chambers 30 (a fixed scroll inward surface side compression chamber 32 and a fixed scroll outward surface side compression chamber 31) are formed whose volumes change relative to each other as the orbiting scroll 2 moves (described later). Hereinafter, the fixed scroll outward surface side compression chamber 31 may be referred to as the first compression chamber, and the fixed scroll inward surface side compression chamber 32 may be referred to as the second compression chamber.

[0018] 1 and 2, the compression mechanism is formed with the above-mentioned compression chamber 30, which is connected to the discharge port 16 at the end of the compression stroke, and a refrigerant suction chamber 40, which is provided upstream of the compression chamber 30 in the refrigerant flow direction and is connected to the suction port 26 of the frame 20. The compression chamber 30 is formed between the fixed base plate 1b and the oscillating base plate 2b, and between the oscillating spiral 2a and the fixed spiral 1a, and the refrigerant suction chamber 40 is provided between the fixed base plate 1b and the oscillating base plate 2b, inside the frame 20 and outside the compression chamber 30.

[0019] 2 and 3, the fixed scroll outward surface compression chamber 31 is formed between the fixed base plate 1b and the oscillating base plate 2b, between the outward surface 1ao of the fixed spiral 1a and the inward surface 2ai of the oscillating spiral 2a. The fixed scroll inward surface compression chamber 32 is formed between the fixed base plate 1b and the oscillating base plate 2b, between the outward surface 2ao of the oscillating spiral 2a and the inward surface 1ai of the fixed spiral 1a.

[0020] As shown in FIG. 2, one of the two suction ports 26 in the frame 20 (see FIG. 1) is located outside the outward surface 1ao of the fixed spiral 1a of the fixed scroll 1 and approximately near the end point 1af of the fixed spiral 1a in the circumferential direction, while the other is located outside the outward surface 2ao of the orbiting spiral 2a of the orbiting scroll 2 and approximately near the end point 2af of the orbiting spiral 2a in the circumferential direction. Here, the end point 1af of the fixed spiral 1a refers to the end located at the outermost periphery of the fixed spiral 1a. Also, the end point 2af of the orbiting spiral 2a refers to the end located at the outermost periphery of the orbiting spiral 2a. In FIG. 2, the two suction ports 26 are located at positions 180° apart.

[0021] 2, arrows indicate the flow of refrigerant drawn from the refrigerant suction chamber 40 into the fixed scroll outboard surface compression chamber 31 and the fixed scroll inboard surface compression chamber 32. The suction passage 41, which serves as a refrigerant inlet for the fixed scroll outboard surface compression chamber 31, is provided near the end point 2af of the oscillating scroll 2a, and the suction passage 42, which serves as a refrigerant inlet for the fixed scroll inboard surface compression chamber 32, is provided near the end point 1af of the fixed scroll 1a. Details of the suction passages 41 and 42 will be described later.

[0022] As shown in Figure 3, tip seals 71 and 72 are embedded in the tip surfaces 1ae and 2ae of the fixed and oscillating spirals 1a and 2a, respectively. These tip seals 71 and 72 prevent refrigerant leakage from gaps G1 and G2 (see Figures 14 and 15) between the tip surfaces 1ae and 2ae of each spiral and the base plate facing these tip surfaces 1ae and 2ae. For example, multiple compression chambers are formed toward the center between the fixed and oscillating spirals 1a and 2a, and the compression chambers closer to the discharge port 16 contain refrigerant that has progressed through the compression process and is therefore higher pressure. The tip seals 71 and 72 provided on the tip surfaces 1ae and 2ae of each spiral prevent refrigerant leakage between radially adjacent compression chambers.

[0023] As shown in Fig. 1, the fixed scroll 1 is fixed to a frame 20 with bolts 7 or the like. A discharge port 16 is formed in the center of the fixed base plate 1b of the fixed scroll 1, through which compressed, high-pressure refrigerant gas is discharged. The compressed, high-pressure refrigerant gas is then discharged into a high-pressure chamber 19 provided in the upper part of the fixed scroll 1. The refrigerant gas discharged into the high-pressure chamber 19 is then discharged into the refrigeration cycle via a discharge pipe 17. The discharge port 16 is provided with a discharge valve 33 that prevents backflow of refrigerant from the high-pressure chamber 19 toward the discharge port 16.

[0024] The orbiting scroll 2 is configured to perform an orbital revolution (orbiting motion) without rotating relative to the fixed scroll 1 by an Oldham ring 14 that prevents rotation. A hollow cylindrical boss 2d is formed in the approximate center of the surface (back surface) of the orbiting scroll 2 opposite the surface on which the orbiting spiral 2a is formed. An eccentric shaft 8a provided at the upper end of the main shaft 8 is inserted into this boss 2d.

[0025] The Oldham ring 14 is interposed between the frame 20 and a thrust bearing surface 2c, which is the surface of the orbiting scroll 2 opposite to the surface on which the orbiting spiral 2a is formed. Protruding Oldham claws are formed on the upper and lower surfaces of the Oldham ring 14. The Oldham claws formed on the upper surface of the Oldham ring 14 are slidably received in Oldham grooves 2co formed in the thrust bearing surface 2c of the orbiting scroll 2, and the Oldham claws formed on the lower surface of the Oldham ring 14 are slidably received in Oldham keyways formed in the orbiting scroll insertion portion 20a of the frame 20. The Oldham ring 14 may also be installed on the surface of the orbiting base plate 2b on which the orbiting spiral 2a is formed.

[0026] The frame 20 has a central opening in its center, and a cylindrical main bearing 21 extending downward is provided in the central opening. The main bearing 21 supports the rotation of the rotary drive means (particularly the main shaft 8). The outer periphery of the frame 20 serves as a housing for accommodating the orbiting scroll 2. The housing has a cylindrical peripheral wall surrounding the meshed fixed and orbiting scrolls 1a and 2a, and a support wall supporting the thrust bearing surface 2c of the orbiting base plate 2b. The outer periphery of the peripheral wall of the frame 20 is fixed to the inside of the sealed container 22 (the upper inner surface of the center shell 22a) by, for example, shrink fitting or welding. The support wall of the frame 20 has an orbiting scroll insertion portion 20a communicating with the central opening and in which the boss portion 2d of the orbiting scroll is disposed. The outer periphery of the support wall of the frame 20 has a suction port 26 formed therein, communicating between the low-pressure chamber 18 below the support wall and the refrigerant suction chamber 40 above the support wall. An Oldham keyway is formed in the orbiting scroll insertion portion 20a.

[0027] The rotational drive means is composed of a rotor 11 fixed to the main shaft 8, a stator 10, and the main shaft 8, which is a rotating shaft. The rotor 11 is fixed to the main shaft 8 by shrink fitting, and is driven to rotate when current is applied to the stator 10, causing the main shaft 8 to rotate. In other words, the stator 10 and the rotor 11 constitute an electric rotating machine. The rotor 11 is disposed below a first balance weight 12 fixed to the main shaft 8 together with the stator 10, which is fixed to the inner surface of the middle part of the center shell 22a by shrink fitting. Electric power is supplied to the stator 10 via a power supply terminal 9 provided on the center shell 22a.

[0028] The main shaft 8 rotates in conjunction with the rotation of the rotor 11, causing the orbiting scroll 2 to orbit. An upper portion of the main shaft 8 (near the eccentric shaft portion 8a) is rotatably supported by a main bearing 21 provided in the center of a frame 20. On the other hand, a lower portion of the main shaft 8 is rotatably supported by an auxiliary bearing (not shown).

[0029] A first balance weight 12 is provided on the upper part of the main shaft 8 to offset imbalance with respect to the center of rotation of the main shaft 8, which occurs when the orbiting scroll 2 is attached to the eccentric shaft portion 8a and oscillates. A second balance weight (not shown) is provided on the lower part of the rotor 11 to offset imbalance with respect to the center of rotation of the main shaft 8, which occurs when the orbiting scroll 2 is attached to the eccentric shaft portion 8a and oscillates. The first balance weight 12 is fixed to the upper part of the main shaft 8 by shrink fitting, and the second balance weight (not shown) is fixed to the lower part of the rotor 11 integrally with the rotor 11.

[0030] [Operation of Scroll Compressor 100] The operation of the scroll compressor 100 will now be described. When current is applied to the power supply terminals 9 shown in Fig. 1, a current flows through the electric wires of the stator 10 of the rotary drive means, generating a magnetic field. This magnetic field acts to rotate the rotor 11. That is, torque is generated between the stator 10 and the rotor 11, causing the rotor 11 to rotate. When the rotor 11 rotates, the main shaft 8 is rotated accordingly. When the main shaft 8 is rotated, the orbiting scroll 2, whose rotation is suppressed by the Oldham ring 14, performs an orbiting motion.

[0031] When the rotor 11 rotates, a first balance weight 12 fixed to the upper part of the main shaft 8 and a second balance weight (not shown) fixed to the lower part of the rotor 11 maintain static and dynamic balance against the eccentric revolution of the orbiting scroll 2. As a result, the orbiting scroll 2, which is eccentrically supported on the upper part of the main shaft 8 and whose rotation is suppressed by the Oldham ring 14, is swung and performs orbital revolution.

[0032] As the rotary drive means is driven in this manner, refrigerant gas flows from the external refrigeration cycle through the suction pipe 15 into the low-pressure chamber 18 inside the center shell 22a. A portion of the refrigerant gas that flows into the low-pressure chamber 18 flows into the refrigerant suction chamber 40 through two suction ports 26 provided in the frame 20. The remaining portion of the refrigerant gas passes through notches (not shown) in the steel plate of the stator 10 to cool the electric rotating machine and the lubricating oil.

[0033] As shown in FIG. 2 , refrigerant flowing into the refrigerant suction chamber 40 is drawn into the compression chamber 30 through the suction passages 41 and 42 due to the relative swinging motion of the oscillating scroll 2a and the fixed scroll 1a of the compression mechanism, thereby starting the suction process (i.e., refrigerant intake into the compression chamber 30). During the suction process of the refrigerant into the compression chamber 30, the volume of the compression chamber 30 expands as the oscillating scroll 2 orbits. However, during the suction process, the compression chamber 30 remains in communication with the suction passages 41 and 42. When the suction passages contact each other at their end points, the compression chamber 30 closes, completing the suction process (i.e., refrigerant intake). After the refrigerant intake is complete, the oscillating motion of the oscillating scroll 2 causes the compression chamber 30 to move toward the center of the oscillating scroll 2, reducing its volume. During this process (i.e., the compression process), the refrigerant gas drawn into the compression chamber 30 is compressed. The compressed refrigerant passes through the discharge port 16 of the fixed scroll 1, pushes open the discharge valve 33, and flows into the high-pressure chamber 19. Then, the refrigerant is discharged from the sealed container 22 through the discharge pipe 17.

[0034] 2, the fixed scroll 1a and the oscillating scroll 2a are meshed at an angle of 180 degrees, and two suction paths (suction path 41 and suction path 42) are provided. Refrigerant is drawn into two compression chambers (the fixed scroll outward surface side compression chamber 31 and the fixed scroll inward surface side compression chamber) formed simultaneously via the suction paths 41 and 42. After the refrigerant is compressed in each compression chamber, the refrigerant compressed in the two compression chambers join together at the center of the oscillating scroll 2 and is discharged from the discharge port 16 to the high-pressure chamber 19.

[0035] The thrust bearing load generated by the pressure of the refrigerant gas in the compression chamber 30 is borne by the frame 20 supporting the thrust bearing surface 2c. Furthermore, the centrifugal force and refrigerant gas load generated on the first balance weight 12 and the second balance weight (not shown) as the main shaft 8 rotates are borne by the main bearing 21 and the auxiliary bearing (not shown). The low-pressure refrigerant gas in the low-pressure chamber 18 and the high-pressure refrigerant gas in the high-pressure chamber 19 are separated by the fixed scroll 1 and the frame 20, and are kept airtight. When the power supply to the stator 10 is stopped, the scroll compressor 100 stops operating.

[0036] FIG. 4 is a vertical cross-sectional view showing a schematic configuration of the fixed scroll 1 of FIG. 1. FIG. 4 shows the fixed scroll 1 shown in FIG. 1 upside down. FIG. 5 is a schematic view of the fixed scroll 1 of FIG. 1 as viewed from below. FIG. 6 is a vertical cross-sectional view showing a schematic configuration of the orbiting scroll 2 of FIG. 1. FIG. 7 is a schematic view of the orbiting scroll 2 of FIG. 1 as viewed from above. FIG. 8 is a horizontal cross-sectional view showing refrigerant suction paths 41, 42 to the compression chamber 30 in the fixed scroll 1 and orbiting scroll 2 of FIG. 2. FIG. 9 is a vertical cross-sectional view showing the B-B cross section of the fixed scroll 1 and orbiting scroll 2 of FIG. 8. FIG. 10 is a vertical cross-sectional view showing the C-C cross section of the fixed scroll 1 and orbiting scroll 2 of FIG. 8. FIG. 11 is a diagram showing the positional relationship between the path extension groove 1br and the end point 2af of the orbiting scroll 2a and the positional relationship between the path extension notch 2br and the end point 1af of the fixed scroll 1a when the rotation phase of the orbiting scroll 2 in FIG. 8 is 0 [rad] (i.e., when refrigerant intake is completed). In FIGS. 8 and 11, the orbiting base plate 2b and its path extension notch 2br, which are located below the A-A cross section in FIG. 1, are shown by dashed lines. FIG. 12 is a vertical cross-sectional view showing the D-D cross section of the fixed scroll 1 and the orbiting scroll 2 in FIG. 11. FIG. 13 is a vertical cross-sectional view showing the E-E cross section of the fixed scroll 1 and the orbiting scroll 2 in FIG. 11. The structures of the fixed scroll 1 and the orbiting scroll 2 will be described in detail with reference to FIGS. 4 to 13.

[0037] 4 and 6, seal grooves 1ar and 2ar having widths smaller than the tooth thicknesses T1 and T2 of the fixed and oscillating scrolls 1a and 2a are formed on the tip surfaces 1ae and 2ae of the respective teeth of the fixed and oscillating scrolls 1a and 2a. The above-mentioned tip seals 71 and 72 that suppress refrigerant leakage are attached to the seal grooves 1ar and 2ar.

[0038] As shown in FIG. 5 , a path expansion groove 1br is formed on the underside (volute-forming surface) of the fixed base plate 1b in a portion of the area where the end point 2af (see FIG. 11 ) of the oscillating volute 2a slides. Specifically, the path expansion groove 1br is formed on the volute-forming surface of the fixed base plate 1b, outside the position of the outward-facing surface 2ao of the oscillating volute 2a when the refrigerant intake is complete (see FIGS. 11 and 12 ). The path expansion groove 1br is formed on the volute-forming surface of the fixed base plate 1b so that at least a portion of the path expansion groove 1br (the portion of the path expansion groove 1br indicated by a checkered pattern in FIG. 8 ) is positioned inside the position of the inward-facing surface 2ai of the oscillating volute 2a during the refrigerant intake process (see FIG. 8 ). Hereinafter, the path expansion groove 1br may be referred to as a first lower surface portion.

[0039] As shown in Figures 4 and 5, the path expansion groove 1br is formed inward from the outer peripheral edge of the spiral-forming surface of the fixed base plate 1b, i.e., with a rim remaining. In Figure 4, the cross-sectional shape of the path expansion groove 1br is rectangular. Here, the fixed base plate 1b of the fixed scroll 1 serves to separate the low-pressure refrigerant suction chamber 40 provided on the spiral-forming surface side from the high-pressure chamber 19 (see Figure 3) provided on the back side. Therefore, as described above, in the fixed base plate 1b, the recess for expanding the suction path 41 is a groove with a rim remaining, thereby expanding the suction path 41 more than conventionally while maintaining the conventional function of sealing between high and low pressure.

[0040] As shown in FIG. 7 , a path expansion notch 2br is formed on the upper surface (volute-forming surface) of the oscillating plate 2b in a portion of the area where the end point 1af (see FIG. 11 ) of the fixed spiral 1a slides. Specifically, the path expansion notch 2br is formed on the volute-forming surface of the oscillating plate 2b, outward of the position of the outward-facing surface 1ao of the fixed spiral 1a when the refrigerant intake is complete (see FIGS. 11 and 13 ). The path expansion notch 2br is formed on the volute-forming surface of the oscillating plate 2b so that at least a portion of the path expansion notch 2br (the portion of the path expansion notch 2br indicated by a checkered pattern in FIG. 8 ) is positioned inward of the position of the inward-facing surface 1ai of the fixed spiral 1a during the refrigerant intake process (see FIG. 8 ). Hereinafter, the path expansion notch 2br may be referred to as a second lower surface portion.

[0041] As shown in Figures 6 and 7, the path expansion notch 2br is formed on the spiral-forming surface of the oscillating plate 2b without leaving any edges at its outer peripheral end, i.e., the outer peripheral end of the oscillating plate 2b is also removed. In Figure 6, the cross-sectional shape of the path expansion notch 2br is a curved surface, such as an R-shape. Here, the oscillating plate 2b of the oscillating scroll 2 serves to bear the gas load in the thrust direction (see Figure 3). Therefore, as described above, the recess for expanding the suction path 42 in the oscillating plate 2b is cut out only on the spiral-forming surface side, while the area of ​​the back surface of the oscillating plate 2b is secured as in the conventional case. This allows the suction path 42 to be expanded compared to the conventional case while maintaining the same thrust load resistance as in the conventional case.

[0042] In addition, in the present disclosure, the path expansion notch 2br is formed in the swing base plate 2b, so the weight of the swing scroll 2 is smaller than that of the conventional one. Therefore, the weight of the balancer (e.g., the first balance weight 12) can be lighter than that of the conventional one, and mechanical loss can be reduced.

[0043] As described above, in the present disclosure, recesses such as the path expansion groove 1br and the path expansion notch 2br are provided in the spiral-forming surfaces of the fixed base plate 1b and the oscillating base plate 2b. These recesses communicate with the compression chamber 30 (the fixed scroll outward-facing surface-side compression chamber 31 or the fixed scroll inward-facing surface-side compression chamber 32) during the refrigerant suction process shown in FIG. 8 and are separated from the compression chamber 30 when the refrigerant intake is completed as shown in FIG. 11. With this configuration, the suction paths 41, 42 of the present disclosure have a larger opening area to the compression chamber 30 than conventional main suction paths 41m, 42m (see FIGS. 9 and 10 ), for example, by the area of ​​the path expansion groove 1br and the path expansion notch 2br that opens to the compression chamber 30 during the refrigerant suction process (the area indicated by the checkered pattern in FIG. 8 ). This reduces suction pressure loss and improves performance. The refrigerant can flow radially into the compression chamber 30 via the path widening groove 1br and the path widening notch 2br.

[0044] 8, the path extension groove 1br has an arc shape extending circumferentially, with one end located near the end point 2af of the oscillating spiral 2a in the circumferential direction and extending approximately 90° from this end along the oscillating spiral 2a. For example, the one end of the path extension groove 1br is located upstream of the area where the end point 2af of the oscillating spiral 2a slides during the suction process of the refrigerant. This allows the refrigerant to flow into the expanded suction path 41e (see FIG. 9) from the circumferential direction during the suction process.

[0045] 8, the path expansion notch 2br has an arc shape extending in the circumferential direction and is provided over a range of approximately 120° in the circumferential direction, extending from the end point 1af of the fixed spiral 1a to the rear of the end point 1af of the fixed spiral 1a. That is, one end of the path expansion notch 2br is provided upstream of the area where the end point 1af of the fixed spiral 1a slides during the refrigerant suction process. This allows the refrigerant to flow into the expanded suction path 42e (see FIG. 10) from the circumferential direction during the refrigerant suction process.

[0046] FIG. 14 is a partial enlarged view of portion Q1 in FIG. 12 . FIG. 15 is a partial enlarged view of portion Q2 in FIG. 13 . Incidentally, if the path expansion groove 1br and the path expansion notch 2br are formed on the spiral-forming surface of the fixed base plate 1b or the oscillating base plate 2b outside the positions of the inward-facing surfaces 2ai and 1ai of the opposing spirals at the completion of refrigerant intake, they will be separated from the compression chamber 30 at the completion of refrigerant intake, even if they are inside the positions of the outward-facing surfaces 2ao and 1ao. In FIGS. 14 and 15 , the positions of the oscillating spiral 2a or the fixed spiral 1a in this case are indicated by dashed lines. However, to prevent refrigerant leakage radially outward from the compression chamber 30, it is preferable that the path expansion groove 1br and the path expansion notch 2br be positioned outside or at the same positions as the outward-facing surfaces 2ao and 1ao of the opposing spirals at the completion of refrigerant intake, as shown in FIGS. 11 to 15 . The reason for this is explained below.

[0047] 14 and 15, gaps G2 and G1 that serve as refrigerant leakage paths are formed between the volute forming surface of the fixed base plate 1b and the tip end surface 2ae of the oscillating volute 2a, and between the volute forming surface of the oscillating base plate 2b and the tip end surface 1ae of the fixed volute 1a, respectively. In the present disclosure, as described above, the fixed base plate 1b is formed with the path expansion groove 1br, and the oscillating base plate 2b is formed with the path expansion notch 2br and the path expansion notch 2br.

[0048] 14 and 15, if the path expansion groove 1br and the path expansion notch 2br are located inside the positions of the outward surfaces 2ao and 1ao of the opposing spirals when the refrigerant intake is complete, the gaps G2 and G1 that serve as leakage paths will be larger than in the conventional design due to the presence of the path expansion groove 1br or the path expansion notch 2br. Therefore, in this case, the refrigerant taken in during the suction process will leak into the refrigerant suction chamber 40 after the refrigerant intake is complete, making it difficult to fully achieve the performance improvement effect achieved by increasing the number of suction paths 41 and 42.

[0049] 16 is an explanatory diagram illustrating the pressure difference between the two compression chambers 30 in FIG. 11 (i.e., when intake is completed). The pressure difference between the fixed scroll outward surface side compression chamber 31 and the fixed scroll inward surface side compression chamber 32 will be described with reference to FIG.

[0050] As shown in Figure 16, in order to prevent a pressure difference from occurring between two compression chambers (the fixed scroll inward surface-side compression chamber 32 and the fixed scroll outward surface-side compression chamber 31) formed at symmetrical positions, it is preferable that the path extension groove 1br of the fixed scroll 1 and the path extension notch 2br of the orbiting scroll 2 be as symmetrical as possible. If a pressure difference occurs between the two compression chambers, wasted force, i.e., loss, will occur from one compression chamber (the one with the higher pressure) to the other compression chamber (the one with the lower pressure). However, if the path extension groove 1br and the path extension notch 2br are made approximately symmetrical, the expansion areas of the refrigerant suction paths 41, 42 to the two compression chambers can be made approximately the same, resulting in a smaller pressure difference between the two compression chambers and reduced loss.

[0051] The configurations of the path expansion groove 1br of the fixed scroll 1 and the path expansion notch 2br of the orbiting scroll 2 are not limited to the above configurations. For example, the range and number of the path expansion grooves 1br and the path expansion notches 2br in the circumferential direction do not have to be the range and number described above, and each of the path expansion groove 1br and the path expansion notch 2br may be divided into multiple parts. An embodiment in this case is shown in embodiment 2.

[0052] Furthermore, for example, the cross-sectional shapes of the path widening groove 1br and the path widening cutout 2br are not limited to the above-described cross-sectional shapes. Modified examples of the path widening cutout 2br shown in FIG.

[0053] Fig. 17 is a vertical cross-sectional view showing a first modified example of the path expansion notch 2br in the orbiting scroll 2 of Fig. 6. Fig. 18 is a vertical cross-sectional view showing a second modified example of the path expansion notch 2br in the orbiting scroll 2 of Fig. 6. The path expansion notch 2br shown in Fig. 17 has a rectangular cross-sectional shape. The path expansion notch 2br shown in Fig. 18 is chamfered and has a triangular cross-sectional shape.

[0054] The cross-sectional shape of the path expansion notch 2br is preferably a shape that ensures as large a cross-sectional area as possible, but any cross-sectional shape may be used as long as the refrigerant can be drawn radially from the outward surface 1ao of the fixed scroll 1a along the outward surface 1ao and the tip end surface 1ae into the space between the fixed scroll 1a and the oscillating scroll 2a (i.e., the compression chamber 30 during the suction process).

[0055] As described above, the scroll compressor 100 of the first embodiment includes a sealed container 22 and a compression mechanism provided in the sealed container 22, the compression mechanism including the compression chamber 30 and the refrigerant suction chamber 40 located upstream of the compression chamber 30 in the refrigerant flow direction. The compression mechanism includes a fixed scroll 1 having a fixed base plate 1b in which a discharge port 16 through which refrigerant from the compression chamber 30 flows and a fixed spiral 1a located on one surface of the fixed base plate 1b, a swinging base plate 2b facing the tooth tip (tip end surface 1ae) of the fixed spiral 1a, and an swinging scroll 2 having a swinging spiral 2a located on one surface of the swinging base plate 2b so as to mesh with the fixed spiral 1a and forming a first compression chamber and a second compression chamber between the fixed spiral 1a and the fixed spiral 1a. A first low surface portion (path expansion groove 1br) is formed on the surface of fixed base plate 1b on the side where fixed spiral 1a is provided, and a second low surface portion (path expansion notch 2br) is formed on the surface of oscillating base plate 2b on the side where oscillating spiral 2a is provided. The first low surface portion is located outside of the outward surface 2ao of oscillating spiral 2a when refrigerant intake is complete, and is formed to communicate with the first compression chamber (fixed scroll outward surface-side compression chamber 31) during the refrigerant intake process. The second low surface portion is located outside of the outward surface 1ao of fixed spiral 1a when refrigerant intake is complete, and is formed to communicate with the second compression chamber (fixed scroll inward surface-side compression chamber 32) during the refrigerant intake process.

[0056] In this way, the first and second low-surface portions increase the cross-sectional area of ​​the suction paths 41, 42 to each compression chamber. Furthermore, because the first and second low-surface portions are positioned outward of the outward surfaces 2ao, 1ao of the opposing spirals when refrigerant intake is complete, the provision of the first and second low-surface portions does not widen the leakage flow path between the tip surfaces 1ae, 1ae of the spirals and the opposing base plate, thereby suppressing refrigerant leakage from the first and second low-surface portions after intake is complete. Therefore, by increasing the cross-sectional area of ​​the suction paths 41, 42 to the compression chambers compared to conventional designs while keeping the refrigerant leakage flow path at a conventional size, suction pressure loss can be reduced, resulting in improved performance.

[0057] In addition, the first lower surface portion is a groove formed on one surface (vortex forming surface) of the fixed base plate 1b, and the second lower surface portion is a notch formed on the outer edge of the oscillating base plate 2b, cut out only on one surface (vortex forming surface) side of the oscillating base plate 2b.

[0058] As a result, the back surface of the fixed base plate 1b and the back surface of the oscillating base plate 2b each have the same area as before, so the function of separating high pressure and low pressure and the function of bearing thrust loads can be maintained as before.

[0059] Embodiment 2 Fig. 19 is a schematic view of the orbiting scroll 102 of a scroll compressor 100A according to Embodiment 2, viewed from above. Fig. 20 is a schematic view of the fixed scroll 101 of the scroll compressor 100 according to Embodiment 2, viewed from below. The scroll compressor 100 according to Embodiment 2 will be described with reference to Figs. 19 and 20. Note that the description of Embodiment 2 will focus on differences from Embodiment 1, and portions that are the same as or equivalent to those of Embodiment 1 will be given the same reference numerals and will not be described again. The scroll compressor according to Embodiment 2 will be referred to as scroll compressor 100A in order to distinguish it from the scroll compressor 100 according to Embodiment 1.

[0060] In the first embodiment described above, only one continuous path expansion groove 1br is provided on the fixed base plate 1b, and only one continuous path expansion notch 2br is provided on the oscillating base plate 2b (see FIGS. 5 and 7). As shown in FIG. 20 , in the second embodiment, the path expansion groove 101br is provided intermittently in the circumferential direction on the fixed base plate 101b and is composed of multiple groove portions (four groove portions R11, R12, R13, and R14 in FIG. 20 ). Hereinafter, the four groove portions R11, R12, R13, and R14 may be referred to simply as groove portion R1 without distinction. Also, as shown in FIG. 19 , the path expansion notch 102br is provided intermittently in the circumferential direction on the oscillating base plate 102b and is composed of multiple notch portions R2 (four notch portions R21, R22, R23, and R24 in FIG. 19 ). In the following, the four cutout portions R21, R22, R23, and R24 may not be distinguished from one another and may simply be referred to as the cutout portion R2. In addition, in the following, the path expansion groove 101br may be referred to as the first bottom portion, and the path expansion cutout 102br may be referred to as the second bottom portion.

[0061] 20 , the circumferential length of each groove portion R1 in the second embodiment is shorter than the circumferential length of the path expansion groove 1br in the first embodiment, and the four groove portions R11, R12, R13, and R14 in the second embodiment are configured by dividing the single path expansion groove 1br in the first embodiment into a plurality of grooves in the circumferential direction. In the second embodiment, the tooth tip surface 2ae of the oscillating spiral 2a is supported by the portion of the fixed base plate 101b between the groove portions R1, and therefore, the oscillating spiral 2a can be prevented from tipping over into the path expansion groove 101br.

[0062] 19, the circumferential length of each cutout portion R2 in the second embodiment is shorter than the circumferential length of the path expansion notch 2br in the first embodiment, and the four R21, R22, R23, and R24 in the second embodiment are configured by dividing the single path expansion notch 2br in the first embodiment into a plurality of portions in the circumferential direction. In the second embodiment, the tooth tip surface 1ae of the fixed spiral 1a is supported by the portion of the oscillating base plate 102b between the cutout portions R2, and therefore, the fixed spiral 1a can be prevented from tipping over into the path expansion notch 102br.

[0063] As described above, in the scroll compressor 100A of the second embodiment, as in the case of the first embodiment, the suction paths 41 and 42 can be expanded more than in the conventional scroll compressor, and the effect of improving performance can be obtained.

[0064] Furthermore, in the scroll compressor 100A of the second embodiment, the first bottom surface portion (path expansion groove 101br) and the second bottom surface portion (path expansion notch 102br) are each provided discontinuously in the circumferential direction, so that the tooth tip surface 2ae of the oscillating volute 2a is supported by the portion of the fixed base plate 101b between the groove portions R1, thereby preventing the oscillating volute 2a from tipping over into the path expansion groove 101br.

[0065] In the above-mentioned first and second embodiments, the fixed volute 1a and the oscillating volute 2a are described as being configured in a generally symmetrical shape, but they may be configured in an asymmetrical shape as long as the above-mentioned effects are obtained. Also, in the above-mentioned first and second embodiments, the first bottom surface portion formed on the fixed base plate 1b is a groove (path expansion groove 1br) formed in the volute-forming surface of the fixed base plate 1b, and the second bottom surface portion formed on the oscillating base plate 2b is a notch (path expansion notch 2br) formed by cutting out only the volute-forming surface of the oscillating base plate 2b, but the first bottom surface portion may be a notch and the second bottom surface portion may be a groove.

[0066] 1 Fixed scroll, 1a Fixed volute, 1ae Tip surface, 1af End point, 1ai Inward surface, 1ao Outward surface, 1ar Seal groove, 1b Fixed base plate, 1br Path expansion groove, 2 Swing scroll, 2a Swing volute, 2ae Tip surface, 2af End point, 2ai Inward surface, 2ao Outward surface, 2ar Seal groove, 2b Swing base plate, 2br Path expansion notch, 2c Swing scroll thrust bearing surface, 2co Oldham groove, 2d Boss portion, 7 Bolt, 8 Main shaft, 8a Eccentric shaft portion, 9 Power supply terminal, 10 Stator, 11 Rotor, 12 First balance weight, 14 Oldham ring, 15 Intake pipe, 16 Discharge port, 17 Discharge pipe, 18 Low pressure chamber, 19 High pressure chamber, 20 Frame, 20a 1. Orbiting scroll insertion portion, 21: main bearing, 22: sealed container, 22a: center shell, 22b: upper shell, 26: suction port, 30: compression chamber, 31: fixed scroll outward surface side compression chamber, 32: fixed scroll inward surface side compression chamber, 33: discharge valve, 40: refrigerant suction chamber, 41: suction path, 41e: expansion suction path, 41m: main suction path, 42: suction path, 42e: expansion suction path, 42m: main suction path, 71: tip seal, 72: tip seal, 100: scroll compressor, 100A: scroll compressor, 101: fixed scroll, 101b: fixed base plate, 101br: path expansion groove, 102: orbiting scroll, 102b: orbiting base plate, 102br: path expansion notch, G1: gap, G2: gap, R1: groove portion, R11: groove portion, R12: groove portion, R13 Groove portion, R2 notch portion, R21 notch portion, R22 notch portion, R23 notch portion, T1 tooth thickness, T2 tooth thickness.

Claims

1. A sealed container, a compression chamber and a refrigerant suction chamber provided upstream of the compression chamber in the refrigerant flow direction are formed, and a compression mechanism provided in the sealed container, The compression mechanism is, a fixed scroll having a fixed base plate formed with a discharge port into which the refrigerant in the compression chamber flows, and a fixed spiral provided on one surface of the fixed base plate, a swing base plate facing the tooth tips of the fixed spiral, and a swing scroll having a swing spiral provided on one surface of the swing base plate so as to mesh with the fixed spiral and forming a first compression chamber and a second compression chamber therebetween, On the surface of the fixed base plate on the side where the fixed spiral is provided, a first low portion is formed, On the surface of the swing base plate on the side where the swing spiral is provided, a second low portion is formed, The first low portion is disposed outside the outer surface of the swing spiral at the completion of refrigerant intake and is formed to communicate with the first compression chamber during the refrigerant intake process, The second low portion is disposed outside the outer surface of the fixed spiral at the completion of the refrigerant intake and is formed to communicate with the second compression chamber during the refrigerant intake process, The first low portion is a groove formed on the one surface of the fixed base plate, The second low portion is a notch formed at the outer edge of the swing base plate and notched only on the one surface side of the swing base plate Scroll compressor.

2. A sealed container, a compression chamber and a refrigerant suction chamber provided upstream of the compression chamber in the refrigerant flow direction are formed, and a compression mechanism provided in the sealed container, The compression mechanism is, a fixed scroll having a fixed base plate formed with a discharge port into which the refrigerant in the compression chamber flows, and a fixed spiral provided on one surface of the fixed base plate, a swing base plate facing the tooth tips of the fixed spiral, and a swing scroll having a swing spiral provided on one surface of the swing base plate so as to mesh with the fixed spiral and forming a first compression chamber and a second compression chamber therebetween, On the surface of the fixed base plate on the side where the fixed spiral is provided, a first low portion is formed, On the surface of the swing base plate on the side where the swing spiral is provided, a second low portion is formed, The first low portion is disposed outside the outer surface of the swing spiral at the completion of refrigerant intake and is formed to communicate with the first compression chamber during the refrigerant intake process, The second lower surface portion is disposed outside the outer surface of the stationary scroll at the time of completion of the intake of the refrigerant, and is formed to communicate with the second compression chamber during the intake process of the refrigerant. The first lower surface portion and the second lower surface portion are each intermittently provided in the circumferential direction. Scroll compressor.

3. Two suction ports connected to the refrigerant suction chamber are provided, and a frame in which the oscillating scroll and the stationary scroll are housed is provided. One of the two suction ports is outside the outer surface of the stationary scroll of the stationary scroll and is provided at the end point of the stationary scroll in the circumferential direction. The remaining one of the two suction ports is outside the outer surface of the oscillating scroll of the oscillating scroll and is provided at the end point of the oscillating scroll in the circumferential direction. The scroll compressor according to claim 1 or 2.

4. A frame in which the oscillating scroll and the stationary scroll are housed is provided. The refrigerant suction chamber is provided between the fixed base plate and the oscillating base plate, inside the frame and outside the compression chamber. The scroll compressor according to claim 1 or 2.