Scroll Fluid Machine

Abstract

To provide a scroll fluid machine which can minimizes the leakage of fluid from a chip clearance even when the scroll fluid machine has an inclined part.SOLUTION: A scroll fluid machine comprises: inner peripheral side wall-body flat parts 3b2, 5b2 arranged on innermost peripheral parts of wall bodies 3b, 5b; an inner peripheral side end-plate flat part 3a2 arranged on innermost peripheral parts of end plates 3a, 5a and corresponding to the inner peripheral side wall-body flat plates 3b2, 5b2; wall-body inclined parts 3b1, 5b1 with wall-body heights thereof continuously increasing; an end-plate inclined part 3a1 whose tooth bottom face opposite a tooth tip of the wall-body inclination part 5b1 is inclined according to inclination of the wall-body inclined part 5b1; a chip seal which makes contact with an opposite tooth bottom to seal fluid; and a discharge port 3c which is formed in a center of the end plates 3a, 5a and through which compressed high-pressure refrigerant circulates. The inner peripheral side wall-body flat parts 3b2, 5b2 and the inner peripheral side end-plate flat part 3a2 are arranged over a range of a first compression chamber 12 which is formed on the innermost periphery at a timing when they communicate with the discharge port 3c.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a scroll fluid machine. [Background technology]

[0002] 2. Description of the Related Art Generally, a scroll fluid machine is known in which a fixed scroll member having a spiral wall body on an end plate is engaged with an orbiting scroll member, and the two scroll members are caused to revolve around each other to compress or expand a fluid.

[0003] As such a scroll fluid machine, a so-called stepped scroll compressor as shown in Patent Document 1 is known. In this stepped scroll compressor, steps are provided at positions along the spiral direction of the tooth tip surface and tooth bottom surface of the spiral wall of the fixed scroll and the orbiting scroll, and the height of the outer periphery side of the wall at each step is made higher than the height of the inner periphery side. Since the stepped scroll compressor compresses not only the circumferential direction of the wall but also the height direction (three-dimensional compression), it is possible to increase the displacement and the compressor capacity compared to a general scroll compressor (two-dimensional compression) that does not have steps.

[0004] However, stepped scroll compressors may suffer from fluid leakage at the steps, resulting in reduced efficiency.

[0005] In response to this, as shown in Patent Document 2, it has been proposed to provide a continuous inclined portion instead of the step portions provided on the wall body and the end plate.

[0006] In Patent Document 2, in consideration of the problem that it is difficult to set the measurement point and improve the measurement accuracy when the tooth tip of the wall is inclined, flat parts are provided on the outermost and / or innermost parts of the wall and end plate to perform shape measurement with high accuracy. It is disclosed that the flat parts of the wall and the end plate are provided over an area of ​​180° or more around the center of the scroll member. However, if the range of the flat parts greatly exceeds 180°, the area of ​​the inclined parts is reduced and the inclination of the inclined parts becomes large, which may increase the fluid leakage. For this reason, it is described that it is preferable that the flat parts of the wall and the flat parts of the end plate are in an area of ​​180° (paragraph

[0018] of Patent Document 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2015-055173 A [Patent Document 2] JP 2018-028300 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, after extensive research by the present inventors, it was found that the compression chamber formed at the innermost circumference of the scroll member has the highest pressure, resulting in a large pressure difference and a large amount of fluid leakage from the tip gap, which is the gap between the tooth tip (wall) and the tooth bottom (end plate).Even if a flat wall portion and a flat end plate portion are provided at the innermost circumference, if an inclined portion exists in the region forming the compression chamber at the innermost circumference, the tip gap at the inclined portion changes depending on the orbital angle, so the tip gap becomes larger and fluid leakage increases further.

[0009] The present disclosure has been made in consideration of the above circumstances, and aims to provide a scroll fluid machine that can reduce fluid leakage from the tip gap as much as possible, even in a scroll fluid machine having an inclined portion. [Means for solving the problem]

[0010] In order to solve the above problems, the scroll fluid machine of the present disclosure includes a first scroll member having a first end plate on which a spiral-shaped first wall body is provided, a second scroll member having a second end plate arranged to face the first end plate and a spiral-shaped second wall body provided on the second end plate, the second wall body meshing with the first wall body to perform a relative orbital motion, and a first end plate and a second end plate arranged to face each other, the first end plate and the second end plate being configured to have a first end plate and a second end plate, the second ... second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second end plate being configured to have a second end plate and the second The inclined portion a wall inclined portion in which the height of the wall increases continuously, an end plate inclined portion in which a tooth bottom surface facing the tooth tip of the wall inclined portion is inclined from the end plate flat portion toward the outer periphery in accordance with the inclination of the wall inclined portion, a tip seal provided in a groove formed in the wall flat portion and the tooth tip of the wall inclined portion, contacting the facing tooth bottom to seal a fluid, and a high pressure port formed in the center of the first end plate or the second end plate and through which a compressed high pressure fluid or a high pressure fluid introduced from the outside flows, and in a region extending 360° or more (excluding 360°) around the center of the scroll member on which the wall flat portion and the end plate flat portion are provided. The outer circumferential position is set in a range from 90° on the inner circumferential side to 90° on the outer circumferential side in the spiral direction of the first wall body and the second wall body from the reference outer circumferential position, when the outer circumferential position that defines the range of the first compression chamber formed at the innermost circumference at the time of communication with the high pressure port is defined as a reference outer circumferential position. Effect of the Invention

[0011] It is possible to reduce fluid leakage from the chip gap as much as possible. [Brief description of the drawings]

[0012] [Figure 1]1 is a vertical cross-sectional view of a fixed scroll and an orbiting scroll of a scroll compressor according to an embodiment of the present disclosure. FIG. [Diagram 2] FIG. 2 is a perspective view showing the orbiting scroll of FIG. [Diagram 3] FIG. 2 is a plan view showing the fixed scroll of FIG. [Figure 4] 4 is a plan view showing a state in which an orbiting scroll is superimposed on a fixed scroll. FIG. [Diagram 5] FIG. 1 is a schematic diagram showing a wall body stretched in the spiral direction. [Figure 6] 5 is a partially enlarged view showing an area Z in FIG. 4. [Figure 7A] FIG. 7 is a side view showing the tip seal gap of the inclined portion shown in FIG. 6, illustrating a state in which the tip seal gap is relatively small. [Figure 7B] FIG. 7 is a side view showing the tip seal gap in the inclined portion shown in FIG. 6, illustrating a state in which the tip seal gap is relatively large. [Figure 8A] 7B is a vertical cross-sectional view of the tip seal and its surroundings, in which a state corresponding to FIG. 7A is shown by solid lines and a state corresponding to FIG. 7B is shown by dashed lines. [Figure 8B] FIG. 4 is a vertical cross-sectional view showing the tip seal and its surroundings in a flat portion. [Figure 9] 4 is a graph showing in-cylinder pressure versus turning angle. [Figure 10A] FIG. 11 is a vertical sectional view showing a modified example, in which a scroll having no step portion is combined with the modified example. [Figure 10B] FIG. 11 is a vertical sectional view showing a modified example in combination with a stepped scroll. [Figure 11A] 1 is a plan view showing the range of a flat portion provided on the innermost circumference, illustrating the state in which the orbiting scroll is superimposed on the fixed scroll. [Figure 11B] FIG. 11B is a plan view showing a modification of FIG. 11A. [Figure 11C] FIG. 11B is a plan view showing a modification of FIG. 11A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. 1 shows a fixed scroll (first scroll member) 3 and an orbiting scroll (second scroll member) 5 of a scroll compressor (scroll fluid machinery) 1. The scroll compressor 1 is used as a compressor that compresses a gas refrigerant (fluid) that performs a refrigeration cycle in, for example, an air conditioner or the like.

[0014] The fixed scroll 3 and the orbiting scroll 5 are a compression mechanism made of metal such as aluminum alloy or iron, and are housed in a housing (not shown). The fixed scroll 3 and the orbiting scroll 5 suck in the fluid introduced into the housing from the outer periphery, and discharge the compressed fluid from a discharge port (high pressure port) 3c in the center of the fixed scroll 3 to the outside.

[0015] The fixed scroll 3 is fixed to the housing and includes a substantially circular end plate (first end plate) 3a and a spiral wall body (first wall body) 3b standing on one side surface of the end plate 3a. The orbiting scroll 5 includes a substantially circular end plate (second end plate) 5a and a spiral wall body (second wall body) 5b standing on one side surface of the end plate 5a. The spiral shape of each of the wall bodies 3b, 5b is defined using, for example, an involute curve or an Archimedes curve.

[0016] The fixed scroll 3 and the orbiting scroll 5 are engaged with their centers separated by the orbital radius ρ, and the phases of the wall bodies 3b, 5b are shifted by 180°, and are assembled so that there is a slight clearance (tip clearance) in the height direction between the tooth tips and tooth bottoms of the wall bodies 3b, 5b of both scrolls at room temperature. As a result, a plurality of pairs of compression chambers are formed between the scrolls 3, 5, surrounded by the end plates 3a, 5a and the wall bodies 3b, 5b, symmetrically with respect to the scroll center. The orbiting scroll 5 revolves around the fixed scroll 3 by an anti-rotation mechanism such as an Oldham ring (not shown).

[0017] The distance L between the opposing surfaces of the two opposing end plates 3a, 5a is provided with an inclined portion that continuously decreases from the outer periphery side toward the inner periphery side of the spiral wall bodies 3b, 5b.

[0018] As shown in FIG. 2, the wall 5b of the orbiting scroll 5 is provided with a wall inclined portion 5b1 whose height continuously increases from the inner periphery side to the outer periphery side. The tooth tip of the wall inclined portion 5b1 faces the tooth bottom surface of the fixed scroll 3, and an end plate inclined portion 3a1 (see FIG. 1) is provided which inclines according to the inclination of the wall inclined portion 5b1. The wall inclined portion 5b1 and the end plate inclined portion 3a1 form a continuous inclined portion. Similarly, as shown in FIG. 1, the wall 3b of the fixed scroll 3 is also provided with a wall inclined portion 3b1 whose height continuously inclines from the inner periphery side to the outer periphery side, and the end plate inclined portion 5a1 facing the tooth tip of the wall inclined portion 3b1 is provided on the end plate 5a of the orbiting scroll 5.

[0019] In this embodiment, the meaning of "continuous" in the inclined portion is not limited to a smoothly connected inclination, but includes a case where small steps that are unavoidably generated during processing are connected in a step-like manner, and the inclined portion is continuously inclined as a whole. However, it does not include a large step portion such as a so-called stepped scroll.

[0020] As shown in FIG. 2, the wall 5b of the orbiting scroll 5 is provided on its innermost and outermost sides with an inner wall flat portion 5b2 and an outer wall flat portion 5b3, respectively, which have a constant height. The inner circumferential side wall flat portion 5b2 is provided over a range from the innermost peripheral position to the outer peripheral position on the center O2 (see FIG. 1) side of the orbiting scroll 5. More specifically, the inner circumferential side wall flat portion 5b2 is provided over a range that defines a first compression chamber 12 (see FIG. 4) that is formed at the innermost peripheral position at the timing of communication with the discharge port 3c. A reference outer peripheral position (wall inclined connection portion 5b4) that defines the outer peripheral position of the first compression chamber 12 is provided on a reference outer peripheral line L1 as shown in FIG. 11A. The reference outer peripheral line L1 indicates the angular position of the wall 5b in the spiral direction and coincides with the outer peripheral position of the first compression chamber 12.

[0021] 2, the outer peripheral side wall flat portion 5b3 is provided over an area of ​​180° from the outermost peripheral end 5b6 of the orbiting scroll 5 toward the inner peripheral side. However, it may be more than 180° or less than 180°. Also, the outer peripheral side wall flat portion 5b3 may be omitted and the wall inclined portion 5b1 may be formed up to the outermost peripheral end. At positions where the wall flat portions 5b2, 5b3 and the wall inclined portion 5b1 are connected, wall inclined connection portions 5b4, 5b5 that serve as bent portions are provided. The wall inclined connection portion 5b4 on the inner peripheral side is provided on the reference outer periphery line L1 as shown in FIG. 11A.

[0022] As shown in FIG. 2, the tooth bottom of the end plate 5a of the orbiting scroll 5 is also provided with an inner circumferential side end plate flat portion 5a2 and an outer circumferential side end plate flat portion 5a3 having a constant height. The inner circumferential side end plate flat portion 5a2 is provided over a range from the innermost peripheral position to the outer circumferential position on the center O2 (see FIG. 1) side of the orbiting scroll 5. More specifically, the inner circumferential side end plate flat portion 5a2 is provided over a range that defines the first compression chamber 12 (see FIG. 4) that is formed at the innermost circumference when communicating with the discharge port 3c. The reference outer circumferential position (end plate inclined connection portion 5a4) that defines the outer circumferential position of the first compression chamber 12 is provided on the reference outer circumferential line L2 as shown in FIG. 11A. The reference outer circumferential line L2 indicates an angular position in the spiral direction and coincides with the outer circumferential position of the first compression chamber 12.

[0023] As shown in FIG. 2, the outer peripheral end plate flat portion 5a3 is provided around the center of the orbiting scroll 5 over an area of ​​180°. At the positions where the end plate flat portions 5a2, 5a3 and the end plate inclined portion 5a1 are connected, end plate inclined connection portions 5a4, 5a5 are provided as bent portions. The end plate inclined connection portion 5a4 on the inner circumference side is provided on the reference outer periphery line L2 as shown in Fig. 11A. Note that the end plate inclined connection portion 5a4 is semicircular in plan view as shown in Fig. 11A, and both ends of the semicircle are provided to coincide with the reference outer periphery line L2.

[0024] As shown in FIG. 3, the fixed scroll 3 is provided with an inner circumferential side wall flat portion 3b2 and an outer circumferential side wall flat portion 3b3, similar to the orbiting scroll 5. The inner circumferential side wall flat portion 3b2 is provided over a range from the innermost peripheral position to the outer circumferential position on the center O1 (see FIG. 1) side of the fixed scroll 3. More specifically, the inner circumferential side wall flat portion 3b2 is provided over a range that defines the first compression chamber 12 (see FIG. 4) that is formed at the innermost peripheral position at the timing of communicating with the discharge port 3c. A wall inclined connection portion 3b4 that is a bent portion is provided at a position where the inner circumferential side wall flat portion 3b2 and the wall inclined portion 3b1 are connected. The wall inclined connection portion 3b4 that is the outer peripheral position of the inner circumferential side wall flat portion 3b2 is provided on a reference outer circumferential line L2 that passes through a reference outer circumferential position that defines the outer circumferential position of the first compression chamber 12, as shown in FIG. 11A.

[0025] As shown in FIG. 3, the tooth bottom of the end plate 3a of the fixed scroll 3 is also provided with an inner circumferential side end plate flat portion 3a2 and an outer circumferential side end plate flat portion 3a3 having a constant height. The inner circumferential side end plate flat portion 3a2 is provided over a range from the innermost peripheral position to the outer circumferential position on the center O1 (see FIG. 1) side of the fixed scroll 3. More specifically, the inner circumferential side end plate flat portion 3a2 is provided over a range that defines the first compression chamber 12 (see FIG. 4) that is formed at the innermost circumference at the timing of communicating with the discharge port 3c. An end plate inclined connection portion 3a4 that is a bent portion is provided at a position where the inner circumferential side end plate flat portion 3a2 and the end plate inclined portion 3a1 are connected. The end plate inclined connection portion 3a4 that is the outer peripheral position of the inner circumferential side end plate flat portion 3a2 is provided on a reference outer circumferential line L1 that passes through a reference outer circumferential position that defines the outer circumferential position of the first compression chamber 12, as shown in FIG. 11A. Incidentally, the end plate inclined connection portion 3a4 has a semicircular shape in plan view as shown in FIG. 11A, and both ends of the semicircle are provided so as to coincide with the reference outer periphery line L1.

[0026] As shown in Fig. 3, two injection ports 10 are provided on the end plate 3a of the fixed scroll 3. The injection ports 10 are through holes that penetrate the end plate 3a in the thickness direction, and the refrigerant that has passed through a condenser (not shown) is guided through the injection ports 10. The injection ports 10 are provided at positions directly opposite each other. The injection ports 10 are formed at positions that open into a second compression chamber located on the outer circumferential side of a first compression chamber that is formed at the timing of communicating with the discharge port 3c.

[0027] Fig. 4 shows a state in which the orbiting scroll 5 shown in Fig. 2 is overlapped and meshed with the fixed scroll 3 shown in Fig. 3. As can be seen from the figure, the first compression chamber 12 formed at the timing of communication with the discharge port 3c, more specifically, at the timing immediately before communication with the discharge port 3c, is defined by the inner circumferential end plate flat portion 3a2 and the inner circumferential side wall flat portion 3b2 of the fixed scroll 3 and the inner circumferential end plate flat portion 5a2 and the inner circumferential side wall flat portion 5b2 of the orbiting scroll 5. In other words, the first compression chamber 12 is defined in a sealed state only by the flat portions 3a2, 3b2, 5a2, and 5b2, and no inclined portion is formed within the first compression chamber 12. This can be understood from the fact that the end plate inclined connection portion 3a4 connecting the inner circumferential side end plate flat portion 3a2 and the end plate inclined portion 3a1 and the end plate inclined connection portion 5a4 connecting the inner circumferential side end plate flat portion 5a2 and the end plate inclined portion 5a1 are not provided in the first compression chamber 12. Two first compression chambers 12 (one pair) are provided symmetrically facing each other with the centers O1, O2 of the scrolls 3, 5 in between.

[0028] 4 shows that the injection port 10 opens into the second compression chamber 14 located on the outer circumferential side of the first compression chamber 12. Two second compression chambers 14 (a pair) are provided symmetrically facing each other with the centers O1, O2 of the scrolls 3, 5 in between.

[0029] FIG. 5 shows the walls 3b, 5b stretched in the spiral direction. As shown in the figure, the inner circumferential wall flat portion 3b2, 5b2 is provided over a distance D2, and the outer circumferential wall flat portion 3b3, 5b3 is provided over a distance D3. The distance D2 is a length corresponding to an area of ​​360° or more around the center O1, O2 of each scroll 3, 5. The distance D3 is a length corresponding to an area of ​​180° around the center O1, O2 of each scroll 3, 5. The wall inclined portion 3b1, 5b1 is provided over a distance D1 between the inner circumferential wall flat portion 3b2, 5b2 and the outer circumferential wall flat portion 3b3, 5b3. If the height difference between the inner circumferential wall flat portion 3b2, 5b2 and the outer circumferential wall flat portion 3b3, 5b3 is h, the inclination φ of the wall inclined portion 3b1, 5b1 is expressed by the following formula. φ=tan -1 (h / D1) (1) In this way, the inclination φ of the inclined portion is constant with respect to the circumferential direction in which the spiral wall bodies 3b and 5b extend. The distance D1 is longer than the distance D2 and is also longer than the distance D3. For example, in this embodiment, the specifications of the scrolls 3 and 5 are as follows: (1) Turning radius ρ [mm]: 2 to 15, preferably 3 to 10 (2) Number of turns of wall 3b and 5b: 1.5 or more and 4.5 or less, preferably 2.0 or more and 3.5 or less (3) Height difference h [mm]: 2 to 20, preferably 5 to 15 (4) h / Lout (height of outermost wall): 0.05 or more and 0.35 or less, preferably 0.1 or more and 0.25 or less (5) Angle range of the inclined part (angle range corresponding to distance D1) [°]: 180 to 1080, preferably 360 to 720 (6) Inclination of the inclined portion φ [°]: 0.2 to 4, preferably 0.5 to 2.5

[0030] FIG. 6 shows an enlarged view of the area indicated by the symbol Z in FIG. 4. As shown in FIG. 6, a tip seal 7 is provided on the tooth tip of the wall body 3b of the fixed scroll 3. The tip seal 7 is made of resin and contacts the tooth bottom of the end plate 5a of the opposing orbiting scroll 5 to seal the fluid. The tip seal 7 is accommodated in a tip seal groove 3d formed in the circumferential direction on the tooth tip of the wall body 3b. A compressed fluid enters this tip seal groove 3d and presses the tip seal 7 from the back side to push it toward the tooth bottom side, thereby contacting the opposing tooth bottom. A tip seal is also provided on the tooth tip of the wall body 5b of the orbiting scroll 5.

[0031] As shown in FIGS. 7A and 7B, the height Hc of the tip seal 7 in the height direction of the wall body 3b is constant in the circumferential direction. When the scrolls 3, 5 revolve relatively, the positions of the tooth tips and the tooth bottoms are shifted by the orbital diameter (orbital radius ρ×2). Due to this positional shift between the tooth tips and the tooth bottoms, the tip clearance between the tooth tips and the tooth bottoms changes in the inclined portion. The tip clearance change amount Δh [mm] is, for example, 0.05 to 1.0, preferably 0.1 to 0.6. For example, in FIG. 7A, the tip clearance T is small, for example, as shown by the solid line in FIG. 8A. On the other hand, when the orbit progresses to the state of FIG. 7B, the tip clearance T becomes large, for example, as shown by the dashed line in FIG. 8B. Even if the tip clearance T changes due to the orbital motion, the tip seal 7 is pressed against the tooth bottom side of the end plate 5a from the back side by the compressed fluid, as shown by the thick arrow in FIG. 8A, so that it can follow and seal.

[0032] On the other hand, since the first compression chamber 12 (see FIG. 4) does not have an inclined portion, the tip clearance does not change according to the orbiting angle as in FIG. 8A. Specifically, as shown in FIG. 8B, the orbiting scroll 5 orbits while maintaining the tip clearance constant. This makes it possible to minimize fluid leakage from the tip gap in the first compression chamber 12 compared to the other compression chambers.

[0033] The above-described scroll compressor 1 operates as follows. A driving source such as an electric motor (not shown) causes the orbiting scroll 5 to revolve around the fixed scroll 3. As a result, fluid is sucked from the outer periphery of each scroll 3, 5, and taken into a compression chamber surrounded by each wall body 3b, 5b and each end plate 3a, 5a. The fluid in the compression chamber is compressed successively as it moves from the outer periphery to the inner periphery, and the compressed fluid is finally discharged from the discharge port 3c formed in the fixed scroll 3. When the fluid is compressed, it is also compressed in the height direction of the wall bodies 3b, 5b at the inclined portions formed by the end plate inclined portions 3a1, 5a1 and the wall body inclined portions 3b1, 5b1, performing three-dimensional compression.

[0034] According to this embodiment, the following advantageous effects are obtained. After providing the chip seal 7, flat portions 3a2, 3b2, 5a2, 5b2 are provided on the innermost portions of the walls 3b, 5b and the end plates 3a, 5a, and the inner wall flat portions 3b2, 5b2 and the inner end plate flat portions 3a2, 5a2 are provided over the range of the first compression chamber 12 formed on the innermost portion at the timing when they are connected to the discharge port 3c. Unlike the inclined portions, the tip clearance T does not change depending on the turning angle between the inner circumferential wall flat portions 3b2, 5b2 and the inner circumferential end plate flat portions 3a2, 5a2, and leakage is less than that of the inclined portions. Therefore, leakage of high-pressure refrigerant from the innermost first compression chamber 12, i.e., the compression chamber with the highest pressure, which is formed at the timing of communication with the discharge port, through the tip gap to other compression chambers located on the outer circumferential side can be suppressed, and efficiency can be improved.

[0035] The above-mentioned effect is shown in Fig. 9. In the figure, the horizontal axis represents the orbiting angle of the orbiting scroll 5, and the vertical axis represents the internal pressure. The internal pressure means the pressure inside the closed compression chamber. In the figure, the dashed line indicates the compression process of Comparative Example 1, which is considered ideal in that no leakage occurs at the tip gap. The dashed line indicates Comparative Example 2, in which an inclined portion is provided up to the first compression chamber 12. The solid line indicates the case in which the first compression chamber 12 is formed only by the flat portions 3a2, 3b2, 5a2, and 5b2, as in this embodiment. As can be seen from the figure, in Comparative Example 2, the leakage in the first compression chamber 12 is relatively large, so the maximum in-cylinder pressure is reached after the swirl angle is more advanced than in Comparative Example 1 and this embodiment. In this embodiment, the maximum in-cylinder pressure is reached after the swirl angle is more advanced than in Comparative Example 1, which has no tip gap leakage, but the tip gap leakage in the first compression chamber 12 is less than in Comparative Example 2, so the maximum in-cylinder pressure can be reached at an earlier swirl angle than in Comparative Example 2.

[0036] The number of turns of the wall bodies 3b, 5b is determined so as to form a second compression chamber 14 located on the outer circumferential side of the innermost first compression chamber 12. Since the second compression chamber 14, which is a closed compression space, is formed on the outer circumferential side of the first compression chamber 12, even if fluid leaks from the first compression chamber 12 to the second compression chamber 14, it will not flow out to the outside (suction side) of the scroll compressor 1, thereby suppressing a decrease in efficiency.

[0037] Since the second compression chamber 14 is a closed space, the effect of injection can be effectively realized by supplying fluid from the injection port 10.

[0038] The regions in which the innermost flat portions 3a2, 3b2, 5a2, and 5b2 are formed can be modified as shown in FIG. 11B or FIG. 11C. As shown in Fig. 11B, the outer peripheral positions of the innermost flat parts 3a2, 3b2, 5a2, 5b2 may be provided on the inner peripheral side in the spiral direction from the reference outer peripheral positions on the reference outer peripheral lines L1, L2 shown in Fig. 11A. Specifically, the outer peripheral positions of the flat parts 3a2, 3b2, 5a2, 5b2 may be provided on the reference outer peripheral lines L1', L2' rotated 90° (-90°) around the center of the end plates 3a, 5a on the inner peripheral side in the spiral direction from the reference outer peripheral lines L1, L2. As a result, a part of the inclined parts 3a1, 3b1, 5a1, 5b1 is formed within the range of the first compression chamber 12, and the inclined parts 3a1, 3b1, 5a1, 5b1 present in the first compression chamber 12 may cause a fluid leakage. However, since the start positions on the inner circumference side of the inclined portions 3a1, 3b1, 5a1, 5b1 are set on the inner circumference side from the reference outer circumference position, when trying to obtain the same inclination height (corresponding to the height difference h in FIG. 5), the dimension in the spiral direction of the entire inclined portions 3a1, 3b1, 5a1, 5b1 can be increased. By increasing the dimension in the spiral direction of the inclined portions 3a1, 3b1, 5a1, 5b1, the inclination φ of the inclined portions 3a1, 3b1, 5a1, 5b1 can be reduced, so that leakage from the inclined portions 3a1, 3b1, 5a1, 5b1 can be suppressed. In this way, compared to FIG. 11A in which the outer circumference positions of the innermost flat portions 3a2, 3b2, 5a2, 5b2 are set at the reference outer circumference position, although the leakage from the inclined portions 3a1, 3b1, 5a1, 5b1 is increased, it is possible to reduce the leakage. Therefore, it is preferable to set the lower limit of the outer circumferential position of the flat portions 3a2, 3b2, 5a2, 5b2 to be at an angle of 90° to the inner circumferential side in the spiral direction from the reference outer circumferential position.

[0039] As shown in FIG. 11C, the outer peripheral positions of the innermost flat portions 3a2, 3b2, 5a2, 5b2 may be located on the outer periphery side in the spiral direction from the reference outer peripheral positions on the reference outer peripheral lines L1, L2 shown in FIG. 11A. Specifically, the outer peripheral positions of the flat portions 3a2, 3b2, 5a2, 5b2 may be located on reference outer peripheral lines L1", L2", which are rotated 90° (+90°) around the center of the end plates 3a, 5a, on the outer periphery side in the spiral direction from the reference outer peripheral lines L1, L2. As a result, since the inclined portions 3a1, 3b1, 5a1, 5b1 are not present within the range of the first compression chamber 12, leakage of fluid from the first compression chamber 12 can be suppressed. However, when the same inclination height (corresponding to the height difference h in FIG. 5) is obtained by setting the start position on the inner circumference side of the inclined portions 3a1, 3b1, 5a1, 5b1 on the outer circumference side from the reference outer circumference position, the dimension in the spiral direction of the entire inclined portions 3a1, 3b1, 5a1, 5b1 becomes small. When the dimension in the spiral direction of the inclined portions 3a1, 3b1, 5a1, 5b1 becomes small, the inclination φ of the inclined portions 3a1, 3b1, 5a1, 5b1 becomes large, so there is a risk of increasing the occurrence of fluid leakage from the inclined portions 3a1, 3b1, 5a1, 5b1. Thus, compared to FIG. 11B in which the outer circumference positions of the innermost flat portions 3a2, 3b2, 5a2, 5b2 are set on the inner circumference side from the reference outer circumference position, the leakage from the inclined portions 3a1, 3b1, 5a1, 5b1 increases, but the fluid leakage from the first compression chamber 12 can be reduced. Therefore, it is preferable to set the upper limit of the outer circumferential position of the flat portions 3a2, 3b2, 5a2, 5b2 to be at an angle of 90° to the outer circumferential side in the spiral direction from the reference outer circumferential position.

[0040] In addition, in this embodiment, the end plate inclined portions 3a1, 5a1 and the wall body inclined portions 3b1, 5b1 are provided on both scrolls 3, 5, but they may be provided on only one of them. Specifically, as shown in FIG. 10A, when a wall body inclined portion 5b1 is provided on one wall body (e.g., the orbiting scroll 5) and an end plate inclined portion 3a1 is provided on the other end plate 3a, the other wall body and the one end plate 5a may be flat. Also, as shown in FIG. 10B, a shape may be combined with a conventional stepped shape, that is, a shape in which an end plate inclined portion 3a1 is provided on the end plate 3a of the fixed scroll 3 while a step portion is provided on the end plate 5a of the orbiting scroll 5.

[0041] In this embodiment, a scroll compressor has been described, but the present disclosure can also be applied to a scroll expander used as an expander.

[0042] The scroll fluid machines according to the above-described embodiments can be understood, for example, as follows. A scroll fluid machine (1) according to one embodiment of the present disclosure includes a first scroll member (3) having a first end plate (3a) on which a spiral-shaped first wall body (3b) is provided, a second scroll member (5) having a second end plate (5a) arranged to face the first end plate and having a spiral-shaped second wall body (5b) on which the second wall body engages with the first wall body to perform a relative orbital motion, and a distance between the opposing surfaces of the first end plate and the second end plate that face each other is set to be equal to or larger than the outer periphery of the first wall body and the second wall body. The wall includes an inclined portion (3a1, 5a1) that decreases continuously from the circumferential side toward the inner circumferential side, a wall flat portion (3b2, 5b2) that is provided on the innermost circumferential portion of at least one of the first wall body and the second wall body and has a constant height, an end plate flat portion (3a2, 5a2) that is provided on the innermost circumferential portion of at least one of the first end plate and the second end plate and corresponds to the wall flat portion, and a wall flat portion (3a2, 5a2) that has a height that is continuous from the wall flat portion toward the outer circumferential side to form the inclined portion. a wall inclined portion (3b1, 5b1) which gradually increases in angle with respect to the inner circumference of the first end plate and the outer circumference of the second end plate, an end plate inclined portion (3a1, 5a1) in which a tooth bottom surface facing the tooth tip of the wall inclined portion is inclined in accordance with the inclination of the wall inclined portion from the end plate flat portion toward the outer circumference, a tip seal (7) which is provided in a groove formed in the wall flat portion and the tooth tip of the wall inclined portion and comes into contact with the facing tooth bottom to seal a fluid, and a high pressure port (3c) which is formed in the center of the first end plate or the second end plate and through which a compressed high pressure fluid or a high pressure fluid introduced from the outside flows, wherein the wall flat portion and the end plate flat portion are provided over a range from an innermost peripheral position to an outer peripheral position on the high pressure port side, and the outer peripheral position is provided in a range from 90° on the inner circumference side to 90° on the outer circumference side in the spiral direction of the first wall body and the second wall body, when an outer peripheral position which defines the range of a first compression chamber (12) formed on the innermost peripheral position at the timing of communication with the high pressure port is taken as a reference outer peripheral position.

[0043] Since an inclined portion is provided where the distance between the opposing faces of the first end plate and the second end plate decreases continuously from the outer periphery side to the inner periphery side of the wall, the fluid sucked in from the outer periphery side is not only compressed as the compression chamber decreases according to the spiral shape of the wall as it moves toward the inner periphery side, but is also further compressed as the distance between the opposing faces of the end plates decreases. This enables three-dimensional compression and makes it possible to achieve a compact size. The inclined portion is designed to decrease continuously, and thus it is possible to reduce fluid leakage compared to a conventional stepped scroll fluid machine in which steps are provided on the wall body and the tooth bottom.

[0044] A continuous inclined portion is not limited to a smoothly connected inclined portion, but also includes an inclined portion in which small steps are connected in a staircase-like manner, and which appears to be inclined continuously when viewed as a whole.

[0045] By providing a wall inclined portion in which the height of the wall increases from the inner circumference side to the outer circumference side, and an end plate inclined portion in which the bottom surface facing the tooth tip of this wall inclined portion inclines in accordance with the inclination of the wall inclined portion, it is possible to form an inclined portion in which the distance between the opposing surfaces of the end plates decreases from the outer circumference side to the inner circumference side.

[0046] The wall inclined portion and the end plate inclined portion may be provided on the first scroll and the second scroll, or on only one of them. When the wall inclined portion is provided on one wall and the end plate inclined portion is provided on the other end plate, the other wall and the one end plate may be flat or may be combined with a conventional stepped shape.

[0047] When the two scroll members revolve relative to each other, the positions of the tooth tips and tooth bottoms of the inclined portions are shifted by the orbital diameter (orbital radius x 2). This positional shift between the tooth tips and tooth bottoms causes a change in the gap between the tooth tips and tooth bottoms (tip clearance). To prevent fluid leakage due to the effect of this change in tip clearance, tip seals are provided at the tooth tips of each wall body corresponding to the inclined portions.

[0048] After providing the tip seal, a flat portion is provided on the innermost periphery of the wall body and the end plate in a range from the innermost periphery position on the high pressure port side to the outer periphery position. The outer periphery position of the flat portion is provided in a range from 90° on the inner periphery side to 90° on the outer periphery side in the spiral direction of the first wall body and the second wall body from the reference outer periphery position, when the outer periphery position that defines the range of the first compression chamber formed on the innermost periphery at the timing when the wall body flat portion and the end plate flat portion are communicated with the high pressure port is taken as the reference outer periphery position. In this disclosure, "a compression chamber is formed" means that a compression space closed by both scroll members is formed.

[0049] Unlike the inclined portion, the tip clearance between the flat portion of the wall and the flat portion of the end plate does not change depending on the turning angle, and leakage is less than with the inclined portion. Therefore, by matching the outer peripheral position of the flat portion with the reference outer peripheral position, it is possible to prevent high-pressure fluid from leaking from the innermost first compression chamber, which is the compression chamber with the highest pressure and is formed when the high-pressure port is connected, through the tip gap into other compression chambers located on the outer periphery, thereby improving efficiency.

[0050] If the outer peripheral position of the flat portion is located on the inner peripheral side in the spiral direction of the reference outer peripheral position, a part of the inclined portion will be formed within the range of the first compression chamber. Therefore, there is a risk of fluid leakage due to the inclined portion existing in the first compression chamber. However, by locating the start position on the inner peripheral side of the inclined portion on the inner peripheral side more inward than the reference outer peripheral position, the dimension of the entire inclined portion in the spiral direction can be increased when attempting to obtain the same inclination height. By increasing the dimension of the inclined portion in the spiral direction, the inclination of the inclined portion can be reduced, so leakage from the inclined portion can be suppressed. Therefore, the lower limit of the outer peripheral position of the flat portion is set to 90° on the inner peripheral side in the spiral direction of the reference outer peripheral position.

[0051] When the outer peripheral position of the flat portion is set within a range of 90° on the outer peripheral side of the reference outer peripheral position in the spiral direction, there is no inclined portion within the range of the first compression chamber, so fluid leakage from the first compression chamber can be suppressed. However, if the start position on the inner peripheral side of the inclined portion is set on the outer peripheral side of the reference outer peripheral position to obtain the same inclination height, the dimension of the inclined portion in the spiral direction as a whole becomes smaller. If the dimension of the inclined portion in the spiral direction becomes smaller, the inclination of the inclined portion becomes larger, so there is a risk of increasing the occurrence of fluid leakage from the inclined portion. Therefore, the upper limit of the outer peripheral position of the flat portion is set to 90° on the outer peripheral side of the reference outer peripheral position in the spiral direction.

[0052] In the scroll fluid machine according to one aspect of the present disclosure, a second compression chamber (14) is formed that is located on the outer circumferential side of the first compression chamber and is formed at the timing of communication with the high pressure port.

[0053] The number of turns of the first wall body and the second wall body is determined so as to form a second compression chamber located on the outer circumferential side of the innermost first compression chamber. Since the second compression chamber, which is a closed compression space, is formed on the outer circumferential side of the first compression chamber, even if fluid leaks from the first compression chamber to the second compression chamber, the fluid will not flow out to the outside of the scroll fluid machine, thereby suppressing a decrease in efficiency.

[0054] In addition, the scroll fluid machine according to one aspect of the present disclosure is provided with an injection port (10) that supplies fluid into the second compression chamber.

[0055] Since the second compression chamber is a closed space, the effect of injection can be effectively realized by supplying a fluid from the injection port. A scroll fluid machine provided with an injection port is suitably used as a compressor that compresses a refrigerant in a refrigeration cycle, and the refrigerant that has passed through a condenser is introduced into the scroll fluid machine. [Explanation of symbols]

[0056] 1. Scroll compressor (scroll fluid machine) 3 Fixed scroll (first scroll member) 3a End plate (1st end plate) 3a1 Slanted end plate 3a2 Inner end plate flat part 3a3 Flat part of outer end plate 3a4 End plate inclined connection 3b Wall (1st wall) 3b1 Wall slope 3b2 Inner peripheral side wall flat part 3b3 Flat part of outer wall 3b4 Wall inclination connection 3c Discharge port (high pressure port) 3d tip seal groove 5. Orbiting scroll (second scroll member) 5a End plate (2nd end plate) 5a1 Slanted end plate 5a2 Inner end plate flat part 5a3 Flat part of outer end plate 5a4 End plate inclined connection 5b Wall (2nd wall) 5b1 Wall slope 5b2 Inner peripheral side wall flat part 5b3 Flat part of outer wall 5b4 Wall inclination connection 5b6 Outermost edge 7 Tip seal 10 Injection port 12 First compression chamber L Distance between opposing surfaces L1, L2 Reference perimeter T Tip Clearance φ Tilt

Claims

1. a first scroll member having a first end plate and a first wall body formed on the first end plate; a second scroll member having a second wall body in a spiral shape provided on a second end plate disposed opposite the first end plate, the second wall body engaging with the first wall body to perform a relative orbital motion; an inclined portion in which a distance between opposing surfaces of the first end plate and the second end plate facing each other continuously decreases from an outer circumferential side to an inner circumferential side of the first wall body and the second wall body; a flat wall portion provided on an innermost periphery of at least one of the first wall portion and the second wall portion, the flat wall portion having a constant height; an end plate flat portion provided on an innermost periphery of at least one of the first end plate and the second end plate and corresponding to the wall flat portion; a wall inclined portion in which the height of the wall forming the inclined portion increases continuously from the wall flat portion toward the outer periphery to form the inclined portion; an end plate inclined portion in which a tooth bottom surface facing the tooth tip of the wall inclined portion is inclined from the end plate flat portion toward an outer periphery in accordance with an inclination of the wall inclined portion; a tip seal provided in a groove formed on the tooth tips of the wall flat portion and the wall inclined portion, the tip seal contacting the opposing tooth bottom to seal a fluid; a high pressure port formed at the center of the first end plate or the second end plate, through which a compressed high pressure fluid or a high pressure fluid introduced from the outside flows; Equipped with the wall flat portion and the end plate flat portion are provided over a range from an innermost peripheral position to an outer peripheral position on the high pressure port side, and in a region that is 360° or more (excluding 360°) around a center of the scroll member in which the wall flat portion and the end plate flat portion are provided, The scroll fluid machine has an outer circumferential position that is located in a range from 90° on the inner circumferential side to 90° on the outer circumferential side in the spiral direction of the first wall body and the second wall body from the reference outer circumferential position, when the outer circumferential position that defines the range of a first compression chamber formed at the innermost circumference at the time of communication with the high pressure port is taken as a reference outer circumferential position.

2. 2. The scroll fluid machine according to claim 1, further comprising a second compression chamber located on an outer circumferential side of the first compression chamber, the second compression chamber being formed at a timing when the first compression chamber communicates with the high pressure port.

3. 3. The scroll fluid machine according to claim 2, further comprising an injection port for supplying fluid into the second compression chamber.

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