Rotary compressor and refrigeration system equipped therewith

Abstract

Lower the height of the rotary compressor. [Solution] An injection channel (61) communicating with an injection pipe (9c) is formed in the first cylinder (31, 41), the middle plate (55), and the second cylinder (31, 41). The injection channel (61) is provided with a first channel (61a) connected to the injection pipe (9c), a second channel (61b, 61c) branching off from the first channel (61a) and communicating with the first cylinder chambers (S1, S2), and a third channel (61b, 61c) branching off from the first channel (61a) and communicating with the second cylinder chambers (S1, S2).

Description

Technical Field

[0001] The present disclosure relates to a rotary compressor and a refrigeration device including the same. The rotary compressor is a compressor that compresses gas in a compression chamber formed in a cylinder by eccentrically rotating a roller in the cylinder. The rotary compressor generally has a vane for partitioning the compression chamber. The rotary compressor includes a so-called rolling piston type in which a vane separate from the roller abuts against the roller while the roller rotates eccentrically, a so-called swing type in which a vane integrally formed with the roller swings as the roller rotates eccentrically, and a so-called hinge vane type in which the tip of the vane is rotatably fitted into a recess on the outer peripheral surface of the roller while the roller rotates eccentrically, etc.

Background Art

[0002] Patent Document 1 discloses a rotary compressor including a first cylinder having a first cylinder chamber and a second cylinder having a second cylinder chamber. In this rotary compressor, a first flow path communicating with the first cylinder chamber is provided in the first cylinder, and a second flow path communicating with the second cylinder chamber is provided in the second cylinder. A first injection pipe for discharging refrigerant from a gas-liquid separator is connected to the first flow path, and a second injection pipe for discharging refrigerant from the gas-liquid separator is connected to the second flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, there is a general demand to reduce the height of rotary compressors for purposes such as reducing refrigerant leakage. However, in the above-mentioned Patent Document 1, injection pipes are directly connected to both the first flow path provided in the first cylinder and the second flow path provided in the second cylinder. Therefore, both the first and second cylinders need to be thick enough to allow direct connection of the injection pipes, and thus the height of the rotary compressor cannot be reduced significantly.

[0005] The purpose of this disclosure is to reduce the height of the rotary compressor. [Means for solving the problem]

[0006] A first aspect of the technology disclosed herein is a rotary compressor to which an injection tube (9c) is connected, comprising: a casing (10); first cylinders (31, 41) disposed inside the casing (10) and having first cylinder chambers (S1, S2); first pistons (34, 44) that rotate eccentrically in the first cylinder chambers (S1, S2); second cylinders (31, 41) disposed inside the casing (10) and having second cylinder chambers (S1, S2); second pistons (34, 44) that rotate eccentrically in the second cylinder chambers (S1, S2); a shaft (90) connected to the first pistons (34, 44) and the second pistons (34, 44); a middle plate (55) disposed between the first cylinders (31, 41) and the second cylinders (31, 41); and the anti-millimeter of the first cylinders (31, 41). The device includes a first bearing (50, 56) positioned on the dollar plate (55) side and supporting the shaft (90), and a second bearing (50, 56) positioned on the opposite side of the second cylinder (31, 41) from the middle plate (55) side and supporting the shaft (90). The first cylinder (31, 41), the middle plate (55), and the second cylinder (31, 41) have injection passages (61) that communicate with the injection pipe (9c). The injection passages (61) include a first passage (61a) connected to the injection pipe (9c), a second passage (61b, 61c) branching off from the first passage (61a) and communicating with the first cylinder chambers (S1, S2), and a third passage (61b, 61c) branching off from the first passage (61a) and communicating with the second cylinder chambers (S1, S2).

[0007] In the first embodiment, the first flow path (61a), which is directly connected to the injection pipe (9c), is branched into a second flow path (61b, 61c) and a third flow path (61b, 61c), so it is not necessary to directly connect the injection pipe (9c) to each of the multiple cylinders (31, 41). Therefore, the height of the rotary compressor (1) can be reduced compared to the case where the injection pipe (9c) is directly connected to each of the multiple cylinders (31, 41).

[0008] A second aspect of the technology disclosed herein is, in the first aspect, the second passage (61b, 61c) is provided with a first reed valve (62, 66) such that one end thereof moves up and down in the axial direction of the shaft (90), and the third passage (61b, 61c) is provided with a second reed valve (62, 66) such that one end thereof moves up and down in the axial direction.

[0009] In the second embodiment, the refrigerant can be introduced into the first cylinder chamber (S1, S2) by the first reed valve (62, 66). In addition, the refrigerant can be introduced into the second cylinder chamber (S1, S2) by the second reed valve (62, 66).

[0010] A third aspect of the technology disclosed herein is that, in the first or second aspect, the second flow path (61b, 61c) or the third flow path (61b, 61c) has a fourth flow path (61d) that extends axially along the shaft (90) and penetrates the middle plate (55), wherein the average flow path diameter of the fourth flow path (61d) is greater than or equal to the average flow path diameter of the first flow path (61a).

[0011] In the third embodiment, the pressure loss of the refrigerant supplied from the injection pipe (9c) to the first cylinder chambers (S1, S2) and the second cylinder chambers (S1, S2) can be reduced compared to the case where the average flow diameter of the fourth flow path (61d) is less than the average flow diameter of the first flow path (61a).

[0012] A fourth aspect of the technology disclosed herein is that, in any one of the first to third aspects, the sum of the flow area of ​​the second flow channel (61b, 61c) and the flow area of ​​the third flow channel (61b, 61c) is equal to or greater than the flow area of ​​the first flow channel (61a).

[0013] In the fourth embodiment, the pressure loss of the refrigerant supplied from the injection pipe (9c) to the first cylinder chambers (S1, S2) and the second cylinder chambers (S1, S2) can be reduced compared to the case where the sum of the flow area of ​​the second flow path (61b, 61c) and the flow area of ​​the third flow path (61b, 61c) is less than the flow area of ​​the first flow path (61a).

[0014] A fifth aspect of the technology disclosed herein further comprises, in any one of the first to fourth aspects, an injection muffler (80) connected to the injection tube (9c), wherein the axial direction of the shaft (90) is vertical, the first bearing (56) is a lower bearing, the second bearing (50) is an upper bearing, a portion of the first flow path (61a) is formed in the first bearing (56), and the lower end of the injection muffler (80) is located below the lower end of the second bearing (50).

[0015] In the fifth embodiment, a portion of the first flow path (61a) is formed into the lower bearing (56), and the lower end of the injection muffler (80) is positioned below the lower end of the second bearing (50), thereby lowering the center of gravity of the rotary compressor (1).

[0016] A sixth aspect of the technology disclosed herein is that, in any one of the first to fifth aspects, the first cylinder (31, 41) has an injection opening (31a, 41a) that opens in one axial direction and a bolt insertion hole (31c, 41c) that penetrates in the axial direction, the first reed valve (62, 66) is attached to the first cylinder (31, 41) by bolts (65, 67) so as to be able to open and close the injection opening (31a, 41a), and fastening holes (62a, 66a) are formed on the surface of the first reed valve (62, 66) facing the first cylinder (31, 41), and the bolts (65, 67) are inserted through the bolt insertion holes (31c, 41c) and fastened to the fastening holes (62a, 66a).

[0017] In the sixth embodiment, bolt insertion holes (31c, 41c) are formed in the first cylinder (31, 41) to accommodate the heads of the bolts (65, 67) and other parts of the bolts (65, 67) other than the tips. Therefore, compared to the case where the bolt insertion holes (31c, 41c) are formed in the first reed valve (62, 66), the first reed valve (62, 66) can be made thinner, and the volume (dead volume) of the space connected to the first cylinder chamber (S1, S2) can be reduced.

[0018] A seventh aspect of the technology disclosed herein is that, in any one of the first to sixth aspects, the first cylinder (31, 41) has vane housing holes (33, 43) formed therein, which house the vanes (36, 46) of the first piston (34, 44), and the end of the second flow path (61b, 61c) on the first cylinder chamber (S1, S2) side is inclined toward the vane housing holes (33, 43) toward the radially inward side of the first cylinder (31, 41).

[0019] In the seventh embodiment, the end of the second flow path (61b, 61c) on the first cylinder chamber (S1, S2) side is inclined toward the vane housing hole (33, 43) radially inward toward the first cylinder (31, 41). This allows the end of the second flow path (61b, 61c) on the first cylinder chamber (S1, S2) side of the second flow path (61b, 61c) and the suction port (17, 18) for refrigerant intake to be spaced apart in the circumferential direction of the suction space (71, 75) when the second flow path (61b, 61c) on the first cylinder chamber (S1, S2) side and the suction port (17, 18) are arranged on both sides of the straight line connecting the vane housing hole (33, 43) and the center of the first cylinder (31, 41). Therefore, it is easier to suppress backflow of refrigerant into the second flow path (61b, 61c).

[0020] An eighth aspect of the technology disclosed herein is, in the seventh aspect, the first cylinder (31, 41) has vane housing holes (33, 43) for housing the vanes (36, 46) of the first piston (34, 44), and one axial end face of the first cylinder (31, 41) has a recess (31a, 41a) that extends radially inward toward the vane housing holes (33, 43), and the bottom surface of the recess (31a, 41a) is, Injection openings (31b, 41b) are formed, and the second flow path (61b, 61c) includes radially extending transverse flow paths (31e, 41e) and connecting passages (31f, 41f) that axially connect the transverse flow paths (31e, 41e) and the injection openings (31b, 41b). The recesses (31a, 41a) house first reed valves (62, 66), and the directions in which the transverse flow paths (31e, 41e) and the recesses (31a, 41a) extend are offset from each other by 5 degrees or more.

[0021] In the eighth aspect, the recesses (31a, 41a) are inclined toward the vane accommodation holes (33, 43) on the radially inner side of the first cylinders (31, 41). Thereby, when the injection openings (31b, 41b) and the suction ports (17, 18) for sucking refrigerant are arranged on both sides of the straight line connecting the vane accommodation holes (33, 43) and the centers of the first cylinders (31, 41), the injection openings (31b, 41b) and the suction ports (17, 18) can be separated from each other in the circumferential direction of the suction spaces (71, 75). Therefore, it is easy to suppress the backflow of the refrigerant into the second flow paths (61b, 61c).

[0022] A ninth aspect of the technology disclosed herein is that, in any one of the first to eighth aspects, discharge ports (51, 57) for discharging refrigerant from the first cylinder chambers (S1, S2) are formed in the first bearings (50, 56), and on the inner peripheral surface of the first cylinders (31, 41), discharge cutouts (37, 47) recessed toward the outer peripheral side are formed such that the inner space of the discharge cutouts (37, 47) overlaps with the discharge ports (51, 57) and the shaft (90) in the axial direction, and the second flow paths (61b, 61c) communicate with the inner space of the discharge cutouts (37, 47).

[0023] In the ninth aspect, since the discharge cutouts (37, 47) are formed, a sudden change in the cross-sectional area of the discharge flow path is suppressed. Therefore, the flow path resistance of the discharge flow path can be reduced.

[0024] A tenth aspect of the technology disclosed herein is that, in any one of the first to ninth aspects, the refrigerant supplied from the injection pipe (9c) to the first cylinder chamber (S1) and the second cylinder chamber (S2) is CO2.

[0025] In the tenth aspect, although refrigerant leakage is likely to occur by using CO2 having a relatively large pressure difference as the refrigerant, refrigerant leakage can be suppressed by reducing the height of the compressor (1).

[0026] The eleventh aspect of the technology disclosed herein targets a refrigeration device (100). The refrigeration device (100) includes the rotary compressor (1) described in any one of the first to tenth aspects.

Brief Description of the Drawings

[0027] [Figure 1] FIG. 1 is a piping system diagram of a refrigeration device including a rotary compressor according to an embodiment. [Figure 2] FIG. 2 is a plan view of the rotary compressor. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 7. [Figure 5] FIG. 5 is a cross-sectional view taken along line V-V of FIG. 7. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 2. [Figure 7] FIG. 7 is an enlarged view of part VII of FIG. 6. [Figure 8] FIG. 8 is a partial cross-sectional view taken along line VIII-VIII of FIG. 2. [Figure 9] FIG. 9 is a diagram showing the operation of the compression mechanism.

Modes for Carrying Out the Invention

[0028] Embodiments of this disclosure will be described in detail below with reference to the drawings. This disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of ​​this disclosure. Since the drawings are for conceptual explanation of this disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for ease of understanding. In the following description, unless otherwise specified, "axial direction" refers to the direction in which the shaft extends, "radial direction" refers to the direction radiating from the shaft, and "circumferential direction" refers to the circumferential direction centered on the shaft. Also, "up" and "down" indicate the direction when the rotary compressor (1) is viewed from the front. Furthermore, hatching may be omitted in the drawings to facilitate understanding of the explanation.

[0029] (1) Refrigeration equipment Figure 1 shows a refrigeration system (100) equipped with a rotary compressor (1) according to this first embodiment. Hereinafter, the rotary compressor (1) may be simply referred to as the compressor (1). The refrigeration system (100) is, for example, an air conditioning system that provides air conditioning for a room. The refrigeration system (100) has an outdoor unit (7) located outside and an indoor unit (8) located inside. The outdoor unit (7) is equipped with a compressor (1), an accumulator (2), a four-way switching valve (3), an outdoor heat exchanger (4a), an economizer heat exchanger (4b), and an expansion valve (5). The indoor unit (8) is equipped with an indoor heat exchanger (6). The outdoor unit (7) and the indoor unit (8) are connected via a connecting pipe (9a) to form a refrigerant circuit (9).

[0030] The compressor (1) compresses low-pressure gaseous refrigerant into high-pressure gaseous refrigerant. The compressor (1) is driven by a compressor motor. A portion of the intermediate-pressure refrigerant flowing from the outdoor heat exchanger (4a) toward the expansion valve (5) is supplied to the compressor (1), and intermediate injection is performed. The intermediate pressure is a predetermined pressure between the pressure of the gaseous refrigerant drawn into the compressor (1) (low pressure) and the pressure of the gaseous refrigerant discharged from the compressor (1) (high pressure). The refrigerant is not particularly limited, but for example, carbon dioxide (CO2).

[0031] The four-way directional valve (3) switches the connection state of the internal piping of the outdoor unit (7). When the refrigeration unit (100) is operating in cooling mode, the four-way directional valve (3) is in the connection state shown by the dashed line in Figure 1. When the refrigeration unit (100) is operating in heating mode, the four-way directional valve (3) is in the connection state shown by the solid line in Figure 1.

[0032] The outdoor heat exchanger (4a) exchanges heat between the refrigerant circulating in the refrigerant circuit (9) and the outdoor air. The outdoor heat exchanger (4a) has a refrigerant flow path through which the refrigerant flows and heat transfer fins that come into contact with the outdoor air. During cooling operation, the outdoor heat exchanger (4a) functions as a refrigerant radiator (condenser), and during heating operation, it functions as a refrigerant absorber (evaporator).

[0033] The expansion valve (5) is an electrically operated valve or solenoid valve with adjustable opening. The expansion valve (5) reduces the pressure of the refrigerant flowing through the internal piping of the outdoor unit (7). The expansion valve (5) controls the flow rate of the refrigerant flowing through the internal piping of the outdoor unit (7).

[0034] The accumulator (2) is located in the piping on the suction side of the compressor (1). The accumulator (2) separates the gas-liquid mixed refrigerant flowing through the refrigerant circuit into gaseous refrigerant and liquid refrigerant, and stores the liquid refrigerant. The gaseous refrigerant separated by the accumulator (2) is sent to the suction port of the compressor (1).

[0035] The economizer heat exchanger (4b) is positioned between the outdoor heat exchanger (4a) and the expansion valve (5). The economizer heat exchanger (4b) performs heat exchange between the refrigerant flowing from the outdoor heat exchanger (4a) toward the expansion valve (5) and the refrigerant flowing through the economizer piping (9b). The economizer piping (9b) is a pipe that branches off from the refrigerant circuit (9) between the economizer heat exchanger (4b) and the expansion valve (5) and is connected to the injection pipe (9c) (described later). An economizer valve (9d) is attached to the economizer piping (9b). The refrigerant flowing through the economizer piping (9b) is depressurized by the economizer valve (9d) and then exchanges heat with the refrigerant flowing from the outdoor heat exchanger (4a) toward the expansion valve (5) in the economizer heat exchanger (4b). The refrigerant flowing from the outdoor heat exchanger (4a) toward the expansion valve (5) and the refrigerant that has undergone heat exchange in the economizer heat exchanger (4b) are supplied to the injection pipe (9c) as refrigerant at an intermediate pressure.

[0036] The refrigeration system (100) includes a refrigerant circuit (9). A compressor (1), a four-way switching valve (3), an outdoor heat exchanger (4a), an expansion valve (5), an indoor heat exchanger (6), and an economizer heat exchanger (4b) are connected to the refrigerant circuit (9). The refrigeration cycle is performed by the flow of refrigerant through the refrigerant circuit (9).

[0037] The refrigeration system (100) performs heating and cooling operations by switching the four-way switching valve (3). In cooling operation, the first refrigeration cycle is performed. Specifically, in the connection state shown by the dashed line in Figure 1, the indoor heat exchanger (6) functions as an evaporator and the outdoor heat exchanger (4a) functions as a radiator. In heating operation, the second refrigeration cycle is performed. Specifically, in the connection state shown by the solid line in Figure 1, the indoor heat exchanger (6) functions as a radiator and the outdoor heat exchanger (4a) functions as an evaporator.

[0038] (2) Rotary compressor Figures 2 to 8 show the compressor (1). In particular, as shown in Figures 3 and 6, the compressor (1) comprises a casing (10), an electric motor (20), and a compression mechanism (30). The electric motor (20) and the compression mechanism (30) are housed within the casing (10). The compressor (1) is configured as a so-called high-pressure dome type, in which the refrigerant compressed in the compression mechanism (30) is discharged into the internal space (R) of the casing (10), and the internal space (R) becomes high-pressure.

[0039] (2-1) Rotary Compressor The casing (10) is formed in an elongated shape. Specifically, the casing (10) comprises a cylindrical body (11) extending in the vertical direction, an upper lid (12) that closes the upper end of the body (11), and a lower lid (13) that closes the lower end of the body (11). A discharge pipe (15) is inserted through the upper part of the body (11). A suction pipe (14) is located at the lower part of the body (11).

[0040] (2-2) Electric motor The electric motor (20) is housed in the casing (10). The electric motor (20) drives the compression mechanism (30). The electric motor (20) is positioned above the mounting plate (54). The electric motor (20) has a cylindrical stator (21) along the inner circumferential surface of the body (11) and a rotor (22) positioned inside the stator (21).

[0041] (2-3) Shaft The shaft (90) is positioned to extend vertically within the casing (10). In other words, the axial direction of the shaft (90) is vertical. The shaft (90) is driven by the electric motor (20). The upper part of the shaft (90) is connected to the rotor (22) of the electric motor (20).

[0042] The lower part of the shaft (90) has, from top to bottom, an upper shaft portion (90a), a first eccentric portion (91), an intermediate shaft portion (90b), a second eccentric portion (92), and a lower shaft portion (90c). The upper shaft portion (90a), the first eccentric portion (91), the intermediate shaft portion (90b), the second eccentric portion (92), and the lower shaft portion (90c) are integrally formed with respect to each other.

[0043] The first eccentric portion (91) and the second eccentric portion (92) are eccentric with respect to the axis of the shaft (90). The first eccentric portion (91) and the second eccentric portion (92) are formed with a larger diameter than the upper shaft portion (90a), the intermediate shaft portion (90b), and the lower shaft portion (90c). The eccentric direction of the first eccentric portion (91) with respect to the rotational axis of the shaft (90) is 180° different from the eccentric direction of the second eccentric portion (92) with respect to the rotational axis of the shaft (90).

[0044] The intermediate shaft portion (90b) is positioned between the first eccentric portion (91) and the second eccentric portion (92). The intermediate shaft portion (90b) connects the first eccentric portion (91) and the second eccentric portion (92).

[0045] (2-4) Compression mechanism The compression mechanism (30) is located inside the casing (10). The compression mechanism (30) compresses the inhaled refrigerant and discharges it into the internal space (R) of the casing (10). The compression mechanism (30) is fixed to a mounting plate (54) which is fixed to the inner circumferential surface of the body (11). Specifically, the compression mechanism (30) is located on the lower surface of the mounting plate (54). The compression mechanism (30) has two cylinders. The compression mechanism (30) comprises a shaft (90), a front head (50) as an upper bearing (second bearing), a first cylinder (31), a first piston (34), a middle plate (55), a second cylinder (41), a second piston (44), and a rear head (56) as a lower bearing (first bearing).

[0046] As shown in Figures 6 and 7, injection passages (61) are formed in the first cylinder (31), middle plate (55), second cylinder (41), and rear head (56). The injection passages (61) communicate with the injection pipe (9c). An injection muffler (80) is connected to the injection pipe (9c), as shown in Figure 6. The lower end of the injection muffler (80) is located below the lower end of the front head (50).

[0047] As shown in an enlarged view in Figure 7, the injection passage (61) has a first passage (61a) connected to the injection tube (9c), a second passage (61b) branching off from the first passage (61a) and communicating with the first cylinder chamber (S1) (described later), and a third passage (61c) branching off from the first passage (61a) and communicating with the second cylinder chamber (S2) (described later). The injection tube (9c) is connected to the first passage (61a) by being inserted from the radially outer side. The sum of the passage area of ​​the second passage (61b) and the passage area of ​​the third passage (61c) is greater than or equal to the passage area of ​​the first passage (61a). The second passage (61b) has a fourth passage (61d) that extends in the axial direction of the shaft (90) and penetrates the middle plate (55). The average channel diameter of the fourth channel (61d) is greater than or equal to the average channel diameter of the first channel (61a).

[0048] (2-4-1) Cylinder The first cylinder (31) and the second cylinder (41) are thick-walled disc-shaped members. Both cylinders (31, 41) have cylinder bores (32, 42) formed in them, particularly as shown in Figures 4 and 5. The cylinder bores (32, 42) are circular holes that penetrate in the thickness direction. The cylinder bores (32, 42) are formed in the central part of the cylinders (31, 41). The first piston (34) is housed in the cylinder bore (32) of the first cylinder (31). The second piston (44) is housed in the cylinder bore (42) of the second cylinder (41).

[0049] In the first cylinder (31), a first cylinder chamber (S1) is formed between the wall surface of the cylinder bore (32) and the first piston (34). In the second cylinder (41), a second cylinder chamber (S2) is formed between the wall surface of the cylinder bore (42) and the second piston (44).

[0050] Each cylinder (31, 41) has a vane housing hole (33, 43) formed therein, which extends radially outward from the inner circumferential surface of the cylinder (31, 41) (i.e., the outer edge of the cylinder bore (32, 42)). This vane housing hole (33, 43) penetrates the cylinder (31, 41) in the thickness direction.

[0051] The first cylinder (31) has a first passage (16a) which is part of the intake passage (16). The first passage (16a) is a bottomed hole extending in the thickness direction of the first cylinder (31). The first passage (16a) is located to the right of the vane housing hole (33) in Figure 4. The second cylinder (41) has a second passage (16b) which is part of the intake passage (16). The second passage (16b) penetrates the second cylinder (41) in the thickness direction. The second passage (16b) is located to the right of the vane housing hole (43) in Figure 5.

[0052] The cylinders (31, 41) have intake ports (17, 18) that extend from the intake passage (16) toward the cylinder chambers (S1, S2). The first intake port (17) of the first cylinder (31) extends from the first passage (16a) toward the first cylinder chamber (S1). As shown in Figure 4, the first intake port (17) of the first cylinder (31) extends from above at a position where it is 30 degrees or less in a clockwise direction away from the vane housing hole (33) when viewed from above. The second intake port (18) of the second cylinder (41) extends from the second passage (16b) toward the second cylinder chamber (S2). As shown in Figure 5, the second intake port (18) of the second cylinder (41) extends from above at a position where it is 30 degrees or less in a clockwise direction away from the vane housing hole (43) when viewed from above. The intake ports (17, 18) extend toward the cylinder chambers (S1, S2) such that, when viewed from the axial direction, they are closer to the vane housing holes (33, 43) than to the intake passage (16).

[0053] A first recess (31a) is formed on the lower end surface (one end surface in the axial direction) of the first cylinder (31), and is elongated in plan view, extending radially inward toward the vane housing hole (33) of the first cylinder (31). A first injection opening (31b) is formed at the radially inward end of the bottom surface of this first recess (31a), opening in one axial direction. A first bolt insertion hole (31c) is formed at the radially outward end of the bottom surface of this first recess (31a), penetrating in the axial direction.

[0054] Between the first recess (31a) and the first cylinder chamber (S1) on the lower end face (one axial end face) of the first cylinder (31), a first communication groove (31d) is formed, which is narrower than the first recess (31a), and extends in the longitudinal direction of the first recess (31a). This first communication groove (31d) corresponds to the first cylinder chamber (S1) side end of the second flow path (61b). Therefore, this first communication groove (31d), that is, the first cylinder chamber (S1) side end of the second flow path (61b), is also inclined toward the vane housing hole (33) towards the radially inward side of the first cylinder (31).

[0055] On the inner circumferential surface of the first cylinder (31), as shown only in Figure 4, a first discharge notch (37) is formed around the end of the second flow path (61b) on the first cylinder chamber (S1) side, recessed outward in an arc shape when viewed from above. The first communication groove (31d), i.e., the second flow path (61b), is in communication with the inner space of the first discharge notch (37).

[0056] As shown in Figure 7, the first cylinder (31) has an upper end portion of the fourth passage (61d), a first transverse passage (31e) extending radially inward from the upper end of the fourth passage (61d), and a first connecting passage (31f) extending downward from the radially inward end of the first transverse passage (31e) and axially connecting the first transverse passage (31e) and the first injection opening (31b). These first transverse passage (31e) and first connecting passage (31f) are part of the second passage (61b). As shown in Figure 4, the first transverse passage (31e) extends from the vane housing hole (33) at an angle of 30 degrees or less in a counterclockwise direction (opposite direction to the first intake port (17)) when viewed from above. The directions in which the first transverse passage (31e) and the first recess (31a) extend are offset by approximately 30 degrees from each other. In other words, the angle α between the first transverse channel (31e) and the first recess (31a) is approximately 30 degrees. By offsetting the directions in which the first transverse channel (31e) and the first recess (31a) extend by 5 degrees or more, that is, by making the angle α 5 degrees or more, the first bolt insertion hole (31c) can be made less likely to interfere with the first transverse channel (31e).

[0057] A first reed valve (62) with an elongated shape is housed in the first recess (31a) of the first cylinder (31), with its longitudinal direction aligned with the longitudinal direction of the first recess (31a). A retaining hole (62a) is formed at one end of the longitudinal direction of the surface of the first reed valve (62) facing the bottom surface of the first recess (31a) of the first cylinder (31).

[0058] As shown in Figure 8, the first reed valve (62) comprises a valve body (63) and a valve retainer (64) facing the valve body (63) from the side opposite the first injection opening (31b). The valve body (63) is an elongated, flat, thin plate-shaped member. The valve body (63) is made of a metal such as spring steel or iron. The valve body (63) is flexible.

[0059] The valve retainer (64) is formed in an elongated plate shape corresponding to the shape of the valve body (63). The radially inner end of the surface of the valve retainer (64) on the valve body (63) side is inclined so that it moves further away from the bottom surface of the first recess (31a) as it moves radially inward.

[0060] The retaining hole (62a) is formed to penetrate both the valve body (63) and the valve retainer (64).

[0061] The first reed valve (62) is attached to the first cylinder (31) by inserting a bolt (65) through the first bolt insertion hole (31c) of the first cylinder (31) and fastening the tip of the bolt (65) to the retaining hole (62a) of the valve retainer (64). The head of the bolt (65) and other parts of the bolt (65) other than the tip are housed in the first bolt insertion hole (31c) of the first cylinder (31). In this state, the first reed valve (62) can open and close the first injection opening (31b) by raising and lowering one end of its (the end opposite the retaining hole (62a)) in the axial direction of the shaft (90). In this way, the first reed valve (62) is provided in the second flow path (61b).

[0062] A second recess (41a) is formed on the upper end surface (one end surface in the axial direction) of the second cylinder (41), and is elongated in plan view, extending radially inward toward the vane housing hole (43) of the second cylinder (41). A second injection opening (41b) is formed at the radially inward end of the bottom surface of this second recess (41a), opening in one axial direction. A second bolt insertion hole (41c) is formed at the radially outward end of the bottom surface of this second recess (41a), penetrating in the axial direction.

[0063] Between the second recess (41a) and the second cylinder chamber (S2) on the lower end surface (one axial end surface) of the second cylinder (41), a second communication groove (41d) is formed, which is narrower than the second recess (41a), and extends in the longitudinal direction of the second recess (41a). This second communication groove (41d) constitutes the second cylinder chamber (S2) side end of the third flow path (61c). Therefore, this second communication groove (41d), that is, the second cylinder chamber (S2) side end of the third flow path (61c), is also inclined toward the vane housing hole (43) towards the radially inward side of the second cylinder (41).

[0064] On the inner circumferential surface of the second cylinder (41), a second discharge notch (47) is formed around the end of the third flow path (61c) on the second cylinder chamber (S2) side, recessed toward the outer circumference in an arc shape when viewed from above. The second communication groove (41d), i.e., the third flow path (61c), is in communication with the inner space of the second discharge notch (47).

[0065] As shown in Figure 7, the second cylinder (41) has a lower end portion of the fourth passage (61d), a second transverse passage (41e) extending radially inward from the lower end of the fourth passage (61d), and a second connecting passage (41f) extending upward from the radially inward end of the second transverse passage (41e) and axially connecting the second transverse passage (41e) and the second injection opening (41b). These second transverse passage (41e) and second connecting passage (41f) are part of the third passage (61c). As shown in Figure 5, the second transverse passage (41e) extends from the vane housing hole (43) at an angle of 30 degrees or less in a counterclockwise direction (opposite direction to the second intake port (18)) when viewed from above. The directions in which the second transverse passage (41e) and the second recess (41a) extend are offset by approximately 30 degrees from each other. In other words, the angle β between the second transverse channel (41e) and the second recess (41a) is approximately 30 degrees. By offsetting the directions in which the second transverse channel (41e) and the second recess (41a) extend by 5 degrees or more, that is, by making the angle β 5 degrees or more, the second bolt insertion hole (41c) can be made less likely to interfere with the second transverse channel (41e).

[0066] A second reed valve (66), having the same configuration as the first reed valve (62), is housed in the second recess (41a) of the second cylinder (41). A retaining hole (66a) is also formed in the second reed valve (66).

[0067] As shown in Figure 8, the second reed valve (66) is attached to the second cylinder (41) in the same manner as the first reed valve (62) by inserting a bolt (67) through the second bolt insertion hole (41c) of the second cylinder (41) and fastening the tip of the bolt (67) to the retaining hole (66a) of the second reed valve (66). The head of the bolt (67) and other parts of the bolt (67) other than the tip are housed in the second bolt insertion hole (41c) of the second cylinder (41). In this state, the second reed valve (66) can open and close the second injection opening (41b) by raising and lowering one end of its (the end opposite the retaining hole (66a)) in the axial direction of the shaft (90). Thus, the second reed valve (66) is provided in the third flow path (61c).

[0068] (2-4-2) Piston The first piston (34) is housed in the first cylinder (31). The first piston (34) rotates eccentrically within the first cylinder chamber (S1). The first piston (34) is configured to slide against both the front head (50) and the middle plate (55).

[0069] As shown in Figure 4, the first piston (34) has a first piston body (roller) (35) and a first vane (36). The first piston body (35) is formed in an annular shape. The first piston body (35) is formed in a slightly thick-walled cylindrical shape. The first eccentric portion (91) of the shaft (90) is inserted through and connected to the first piston body (35). The first piston body (35) pivots along the inner circumferential surface of the first cylinder chamber (S1) of the first cylinder (31) as the first eccentric portion (91) rotates.

[0070] The first vane (36) is integrally projected from the outer circumferential surface of the first piston body (35). The first vane (36) is housed in the vane housing hole (33) of the first cylinder (31). The first vane (36) is sandwiched from both sides by bushings (70) fitted into the vane housing hole (33). The first vane (36) is supported by the first cylinder (31) via these bushings (70) so as to be able to swing and move back and forth. The first vane (36) divides the first cylinder chamber (S1) into a first intake space (71) and a first discharge space (72). When the first piston (34) rotates, the first vane (36) restricts the rotation of the first piston (34) itself. As a result, the first piston (34) rotates along the inner surface of the first cylinder chamber (S1) without rotating.

[0071] The second piston (44) is identical to the first piston (34) in shape, dimensions, and material. The first piston (34) and the second piston (44) are positioned inverted relative to each other in the vertical direction.

[0072] The second piston (44) is housed in the second cylinder (41). The second piston (44) rotates eccentrically in the second cylinder chamber (S2). The second piston (44) is configured to slide against both the rear head (56) and the middle plate (55).

[0073] As shown in Figure 5, the second piston (44) has a second piston body (roller) (45) and a second vane (46). The second piston body (45) is formed in an annular shape. The second piston body (45) is formed in a slightly thick-walled cylindrical shape. The second piston body (45) is connected to the shaft (90) by having the second eccentric portion (92) of the shaft inserted through it. The second piston body (45) pivots along the inner circumferential surface of the second cylinder chamber (S2) of the second cylinder (41) as the second eccentric portion (92) rotates.

[0074] The second vane (46) is integrally projected from the outer circumferential surface of the second piston body (45). The second vane (46) is housed in the vane housing hole (43) of the second cylinder (41). The second vane (46) is sandwiched from both sides by a bush (70) fitted into the vane housing hole (43). The second vane (46) is supported by the second cylinder (41) via this bush (70) so as to be able to swing and move back and forth. The second vane (46) divides the second cylinder chamber (S2) into a second intake space (75) and a second discharge space (not shown). When the second piston (44) is swirling, the second vane (46) restricts the rotation of the second piston (44) itself. As a result, the second piston (44) swivels along the inner surface of the second cylinder chamber (S2) without rotating.

[0075] (2-4-3) Front Head The front head (50) is positioned on the side of the first cylinder (31) opposite the middle plate (55). The front head (50) closes the axial end of the first cylinder (31). Specifically, the front head (50) closes the upper end surface (the surface on the motor (20) side) of the first cylinder (31). The front head (50) is an example of a closing member of this disclosure. The front head (50) comprises a first main body portion (50a) and an upper bearing portion (50b). The first main body portion (50a) and the upper bearing portion (50b) are integrally formed.

[0076] The first main body (50a) is formed in a generally circular, thick plate shape. The lower surface of the first main body (50a) is in close contact with the upper end surface of the first cylinder (31). The upper bearing portion (50b) is formed in a cylindrical shape that extends from the first main body (50a) toward the electric motor (20) side (upper side in Figure 3). The upper bearing portion (50b) is positioned in the center of the first main body (50a). The upper bearing portion (50b) rotatably supports the upper shaft portion (90a) of the shaft (90).

[0077] As shown in Figure 8, the first main body (50a) has a first discharge port (51). The first discharge port (51) penetrates the first main body (50a) in the thickness direction. The first discharge port (51) connects the internal space (R) and the first discharge space (72). Also, as shown in Figure 4, the arc-shaped edge of the first discharge notch (37) overlaps the outer periphery of the first discharge port (51). Furthermore, the inner space of the first discharge notch (37) overlaps the first discharge port (51) in the axial direction of the shaft (90).

[0078] The portion of the first main body (50a) surrounding the first discharge port (51) is a first thin-walled portion (52) which has a thinner axial thickness than other parts.

[0079] A first discharge valve (53), which is a reed valve, is provided at the first discharge port (51). The first discharge valve (53) is positioned to cover the first discharge port (51). The first discharge valve (53) moves away from the first discharge port (51) when the pressure of the refrigerant in the first discharge space (72) of the first cylinder chamber (S1) exceeds a predetermined value. When the first discharge valve (53) moves away from the first discharge port (51), the refrigerant is discharged through the first discharge port (51) from the first discharge space (72) of the first cylinder chamber (S1) into the internal space (R). After the refrigerant has been discharged into the internal space (R), the first discharge valve (53) again covers the first discharge port (51).

[0080] (2-4-4) Middle Plate The middle plate (55) is positioned between the first cylinder (31) and the second cylinder (41). The middle plate (55) closes the axial end of the first cylinder (31) and the axial end of the second cylinder (41). Specifically, the middle plate (55) closes the lower end surface of the first cylinder (31) and the upper end surface of the second cylinder (41).

[0081] A central hole is formed in the middle of the middle plate (55), passing through it axially. The intermediate shaft portion (90b) of the shaft (90) is inserted through the central hole.

[0082] As shown in Figure 3, the middle plate (55) has an intermediate passage (16c) which is part of the intake passage (16). The intermediate passage (16c) penetrates the middle plate (55) in the axial direction. The intermediate passage (16c) connects the first passage (16a) and the second passage (16b).

[0083] The middle plate (55) is penetrated by the fourth channel (61d), which extends axially from the second channel (61b) of the injection channel (61).

[0084] (2-4-5) Rear Head The rear head (56) is positioned on the side of the second cylinder (41) opposite the middle plate (55). The rear head (56) closes the axial end of the second cylinder (41). Specifically, the rear head (56) closes the lower end surface of the second cylinder (41) (the surface opposite to the electric motor (20)). The rear head (56) is an example of a closing member of this disclosure.

[0085] The upper surface of the rear head (56) is in close contact with the lower end surface of the second cylinder (41). The rear head (56) rotatably supports the lower shaft portion (90c) of the shaft (90).

[0086] The rear head (56) has a first insertion hole (19) into which the intake pipe (14) is inserted, and a second insertion hole (60) into which the injection pipe (9c) is inserted. The first insertion hole (19) and the second insertion hole (60) each extend radially.

[0087] A lower passage (16d), which is part of the suction passage (16), extends from the first insertion hole (19). The lower passage (16d) extends upward along the axial direction from the tip of the first insertion hole (19). The upper end of the lower passage (16d) communicates with the second passage (16b).

[0088] An injection channel (61) extends from the second insertion hole (60). A portion of the first channel (61a) of the injection channel (61) is formed in the rear head (56).

[0089] As shown in Figures 7 and 8, the rear head (56) has a second discharge port (57). The second discharge port (57) penetrates the rear head (56) in the thickness direction. The second discharge port (57) communicates the internal space (R) with the second discharge space (not shown). Also, as shown in Figure 5, the arc-shaped edge of the second discharge notch (47) overlaps the outer periphery of the second discharge port (57). Furthermore, the inner space of the second discharge notch (47) overlaps the second discharge port (57) in the axial direction of the shaft (90).

[0090] The area around the second discharge port (57) in the rear head (56) is a second thin-walled section (58) that is thinner in the axial direction than other parts.

[0091] A second discharge valve (59) is provided at the second discharge port (57). The second discharge valve (59) is positioned to cover the second discharge port (57). The second discharge valve (59) moves away from the second discharge port (57) when the pressure of the refrigerant in the second discharge space (not shown) exceeds a predetermined value. When the second discharge valve (59) moves away from the second discharge port (57), the refrigerant is discharged through the second discharge port (57) from the second discharge space (not shown) into the internal space (R). After the refrigerant has been discharged into the internal space (R), the second discharge valve (59) again covers the second discharge port (57).

[0092] (3) Operating Next, the operation of the compressor (1) will be explained with reference to Figure 9. The refrigerant compression operation by the first cylinder (31) and the first piston (34) and the refrigerant compression operation by the second cylinder (41) and the second piston (44) are basically the same, differing only by a 180° phase difference. In the following explanation, the refrigerant compression operation by the first cylinder (31) and the first piston (34) will be described in detail, while the refrigerant compression operation by the second cylinder (41) and the second piston (44) will not be explained.

[0093] In the compressor (1), when the electric motor (20) is started and the rotor (22) is rotated, the shaft (90) rotates and the first eccentric part (91) rotates eccentrically. As the first eccentric part (91) rotates eccentrically, the first piston (34) rotates along the inner surface of the first cylinder (31) while restricting its rotation.

[0094] The suction stroke for drawing refrigerant into the first cylinder chamber (S1) will now be described. When the shaft (90) rotates slightly from a state where its rotation angle is 0° (state shown in Figure 9(A)), the contact point between the first piston (34) and the first cylinder (31) passes the inner end of the first suction port (17). At this time, the suction of refrigerant into the first suction space (71) begins.

[0095] Refrigerant is drawn in from the suction pipe (14) through the suction passage (16) and the first suction port (17). As the rotation angle of the shaft (90) increases, the volume of the first suction space (71) gradually increases, and the amount of refrigerant drawn into the first suction space (71) increases (as shown in Figures 9(B) to (H)). This refrigerant suction stroke continues until the rotation angle of the shaft (90) reaches 360°, after which the process transitions to the discharge stroke.

[0096] The discharge stroke, in which the refrigerant is compressed and discharged in the first cylinder chamber (S1), will now be described. When the shaft (90) rotates slightly from a state where its rotation angle is 0° (state shown in Figure 9(A)), the contact point between the first piston (34) and the first cylinder (31) passes the inner circumference end of the first intake port (17) again. At this time, the containment of the refrigerant in the first intake space (71) is completed.

[0097] The first intake space (71), which was connected to the first intake port (17), becomes the first discharge space (72), which is connected only to the first discharge port (51). From this state, compression of the refrigerant in the first discharge space (72) begins. As the rotation angle of the shaft (90) increases, the volume of the first discharge space (72) decreases and the pressure in the first discharge space (72) increases. When the pressure in the first discharge space (72) exceeds a predetermined pressure, the first discharge valve (53) opens.

[0098] When the first discharge valve (53) opens, the refrigerant in the first discharge space (72) is discharged from the first discharge port (51), flows into the internal space (R) within the casing (10), and is then discharged to the outside of the compressor (1) via the discharge pipe (15). This refrigerant discharge stroke continues until the rotation angle of the shaft (90) reaches 360°, after which the process transitions to the suction stroke.

[0099] In this manner, the intake stroke and discharge stroke alternate in the first cylinder chamber (S1). In the second cylinder chamber (S2), the intake stroke and discharge stroke alternate with a 180° phase difference relative to the first cylinder chamber (S1). As a result, the compressor (1) continuously compresses the refrigerant.

[0100] Here, intermediate-pressure refrigerant, i.e., carbon dioxide (CO2), is injected into the first cylinder chamber (S1) and the second cylinder chamber (S2) from the injection passage (61) while compression is in progress. Specifically, if the pressure in the injection passage (61) is higher than that in the first cylinder chamber (S1), intermediate-pressure refrigerant is injected into the first cylinder chamber (S1) from the injection passage (61). On the other hand, if the pressure in the first cylinder chamber (S1) increases and the pressure in the first cylinder chamber (S1) becomes higher than that in the injection passage (61), the end of the first reed valve (62) provided in the injection passage (61) on the side of the retaining hole (62a) is pressed against the periphery of the first injection opening (31b), blocking the injection passage (61) and stopping the supply of intermediate-pressure refrigerant.

[0101] Similarly, if the pressure in the injection passage (61) is higher than that in the second cylinder chamber (S2), intermediate-pressure refrigerant is injected from the injection passage (61) into the second cylinder chamber (S2). On the other hand, if the pressure in the second cylinder chamber (S2) increases and becomes higher than that in the injection passage (61), the end of the second reed valve (66) provided in the injection passage (61) on the side of the retaining hole (66a) is pressed against the periphery of the second injection opening (41b), blocking the injection passage (61) and stopping the supply of intermediate-pressure refrigerant. In this way, the rotary compressor (1) improves compression efficiency by injecting intermediate-pressure refrigerant.

[0102] (6) Effects of the Embodiment In the rotary compressor (1) according to this embodiment, the first flow path (61a), which is directly connected to the injection pipe (9c), is branched into a second flow path (61b) and a third flow path (61c), so the injection pipe (9c) does not need to be directly connected to each of the two cylinders (31, 41). Therefore, the height of the compressor (1) can be reduced compared to the case where the injection pipe (9c) is directly connected to each of the two cylinders (31, 41). In this embodiment, CO2, which has a relatively large pressure difference, is used as the refrigerant, so refrigerant leakage is likely to occur, but by reducing the height of the compressor (1) in this way, refrigerant leakage can be suppressed.

[0103] Furthermore, since a first reed valve (62) is provided in the second flow path (61b), the refrigerant can be introduced into the first cylinder chamber (S1) by the first reed valve (62). Also, since a second reed valve (66) is provided in the third flow path (61c), the refrigerant can be introduced into the second cylinder chamber (S2) by the second reed valve (66).

[0104] Furthermore, by making the average flow diameter of the fourth flow path (61d) greater than or equal to the average flow diameter of the first flow path (61a), the pressure loss of the refrigerant supplied from the injection pipe (9c) to the first cylinder chamber (S1) and the second cylinder chamber (S2) can be reduced compared to the case where it is less than the average flow diameter.

[0105] Furthermore, the sum of the flow area of ​​the second flow path (61b) and the flow area of ​​the third flow path (61c) was made greater than or equal to the flow area of ​​the first flow path (61a). This reduces the pressure loss of the refrigerant supplied from the injection pipe (9c) to the first cylinder chamber (S1) and the second cylinder chamber (S2) compared to the case where the sum is less than the flow area of ​​the first flow path (61a).

[0106] Furthermore, by forming a portion of the first flow path (61a) connected to the injection pipe (9c) in the rear head (56), and positioning the lower end of the injection muffler (80) below the lower end of the front head (50), the center of gravity of the compressor (1) can be lowered.

[0107] Furthermore, the first bolt insertion hole (31c) is formed in the first cylinder (31), and the head of the bolt (65) and other parts of the bolt (65) other than the tip are housed in the first bolt insertion hole (31c). Therefore, compared to the case where the first bolt insertion hole (31c) is formed in the first reed valve (62), the first reed valve (62) can be made thinner, and the volume of the space connected to the first cylinder chamber (S1) can be made smaller. Also, the second bolt insertion hole (41c) is formed in the second cylinder (41), and the head of the bolt (67) and other parts of the bolt (67) other than the tip are housed in the second bolt insertion hole (41c). Therefore, compared to the case where the second bolt insertion hole (41c) is formed in the second reed valve (66), the second reed valve (66) can be made thinner, and the volume of the space connected to the second cylinder chamber (S2) can be made smaller.

[0108] Furthermore, the second flow path (61b) and the first intake port (17) are arranged on both sides of the straight line connecting the vane housing hole (33) and the center of the first cylinder (31). The end of the second flow path (61b) on the first cylinder chamber (S1) side is inclined toward the vane housing hole (33) towards the radially inward side of the first cylinder (31). Therefore, the end of the second flow path (61b) on the first cylinder chamber (S1) side and the first intake port (17) are spaced apart in the circumferential direction of the first intake space (71), making it easier to suppress backflow of refrigerant into the second flow path (61b).

[0109] Similarly, the third flow path (61c) and the second suction port (18) are arranged on both sides of the straight line connecting the vane housing hole (43) and the center of the second cylinder (41). The end of the third flow path (61c) on the second cylinder chamber (S2) side is inclined toward the vane housing hole (43) towards the radially inward side of the second cylinder (41). Therefore, the end of the third flow path (61c) on the second cylinder chamber (S2) side and the second suction port (18) are spaced apart in the circumferential direction of the second suction space (75), making it easier to suppress backflow of refrigerant into the third flow path (61c).

[0110] Furthermore, the first recess (31a) in which the first injection opening (31b) is formed is inclined toward the vane housing hole (33) toward the radially inward side of the first cylinder (31). Therefore, the first injection opening (31b) and the first intake port (17) are spaced apart in the circumferential direction of the first intake space (71), making it easier to suppress the backflow of refrigerant into the second flow path (61b).

[0111] Similarly, the second recess (41a) in which the second injection opening (41b) is formed is inclined toward the vane housing hole (43) toward the radially inward side of the second cylinder (41). Therefore, the second injection opening (41b) and the second intake port (18) are spaced apart in the circumferential direction of the second intake space (75), making it easier to suppress the backflow of refrigerant into the third flow path (61c).

[0112] Furthermore, since the first discharge notch (37) and the second discharge notch (47) are formed, abrupt changes in the cross-sectional area of ​​the discharge channel are suppressed. Therefore, the flow resistance of the discharge channel can be reduced.

[0113] <Other Embodiments> Furthermore, the piston (34,44) and the vane (36,46) do not necessarily have to be integrally formed. The piston (34,44) and the vane (36,46) may also be connected by a hinge.

[0114] Furthermore, in the above embodiment, both the end of the second flow path (61b) on the first cylinder chamber (S1) side and the end of the third flow path (61c) on the second cylinder chamber (S2) side are inclined toward the vane housing holes (33, 43) toward the radially inward side of the first cylinder (31) and the second cylinder (41). However, only one of the end of the second flow path (61b) on the first cylinder chamber (S1) side and the end of the third flow path (61c) on the second cylinder chamber (S2) side may be inclined toward the vane housing holes (33, 43) toward the radially inward side of the first cylinder (31) and the second cylinder (41).

[0115] Furthermore, in the above embodiment, both the first recess (31a) of the first cylinder (31) and the second recess (41a) of the second cylinder (41) are inclined toward the vane housing holes (33, 43) toward the radially inward direction of the first cylinder (31) and the second cylinder (41). However, only one of the first recess (31a) and the second recess (41a) may be inclined toward the vane housing holes (33, 43) toward the radially inward direction of the first cylinder (31) and the second cylinder (41).

[0116] Furthermore, in the above embodiment, a second insertion hole (60) into which an injection pipe (9c) is inserted is provided in the rear head (56), and a part of the first flow path (61a) of the injection flow path (61) is formed in the rear head (56). However, it is not necessary to form the injection flow path (61) in the rear head (56). Alternatively, an insertion hole into which an injection pipe (9c) is inserted, the entirety of the first flow path (61a), and the entirety of the second flow path (61b) may be formed in either the first cylinder (31) or the second cylinder (41). Or, the insertion hole (60) into which the injection pipe (9c) is inserted, the entirety of the first flow path (61a), and the branching portion to the second flow path (61b) and the third flow path (61c) may be formed in the middle plate (55).

[0117] While embodiments and modifications have been described above, it will be understood that a variety of changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, the embodiments, modifications, and other embodiments described above may be combined or substituted as appropriate, as long as they do not impair the functions covered by this disclosure.

[0118] The designations "1st," "2nd," "3rd," etc., mentioned above are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of those terms. [Industrial applicability]

[0119] As described above, this disclosure is useful for rotary compressors and refrigeration systems equipped therewith. [Explanation of symbols]

[0120] 1. Rotary Compressor S1 First Cylinder Chamber S2 Second Cylinder Chamber 9c injection tube 10 Casing 31. First cylinder 31a 1st recess 31b First injection opening 31c First bolt insertion hole 31e 1st horizontal flow path 31f 1st connecting road 33 vane housing holes 34. First piston 36 First Bane 41 Second Cylinder 41a Second recess 41b Second injection opening 41c Second bolt insertion hole 41e 2nd horizontal flow path 41f 2nd connecting road 43 vane housing holes 44. Second piston 46. ​​Second Bane 50 Front head (2nd bearing) 51 1st outlet 55 Middle Plate 56 Rear head (first bearing, lower bearing) 57 2nd discharge port 61 Injection channel 61a First channel 61b Second channel 61c Third channel 61d Fourth channel 62 First reed valve 62a Fastening hole 65 volts 66. Second reed valve 66a Fastening hole 67 volts 80 Injection Muffler 90 shaft 100 Refrigeration equipment

Claims

1. A rotary compressor to which an injection tube (9c) is connected, Casing (10) and The casing (10) is disposed inside the first cylinder (31, 41) which has first cylinder chambers (S1, S2), In the first cylinder chambers (S1, S2), the first pistons (34, 44) rotate eccentrically, The casing (10) is disposed inside the second cylinder (31, 41) which has second cylinder chambers (S1, S2), In the second cylinder chambers (S1, S2), there are second pistons (34, 44) that rotate eccentrically, A shaft (90) connected to the first piston (34, 44) and the second piston (34, 44), A middle plate (55) is positioned between the first cylinder (31, 41) and the second cylinder (31, 41), The first bearing (50, 56) is positioned on the side opposite the middle plate (55) of the first cylinder (31, 41) and pivotally supports the shaft (90), The second cylinder (31, 41) is positioned on the side opposite the middle plate (55) and comprises a second bearing (50, 56) that pivotally supports the shaft (90), The first cylinder (31, 41), the middle plate (55), and the second cylinder (31, 41) are formed with an injection channel (61) that communicates with the injection tube (9c). The injection channel (61) is The first flow path (61a) connected to the injection tube (9c), A second flow path (61b, 61c) branches off from the first flow path (61a) and communicates with the first cylinder chambers (S1, S2), It has a third flow path (61b, 61c) that branches off from the first flow path (61a) and communicates with the second cylinder chambers (S1, S2), A recess (31a, 41a) is formed on one axial end face of the first cylinder (31, 41), and an injection opening (31b, 41b) is formed on the bottom surface of the recess (31a, 41a). The second flow path (61b, 61c) includes a radially extending transverse flow path (31e, 41e) and a connecting passage (31f, 41f) that axially connects the transverse flow path (31e, 41e) and the injection opening (31b, 41b). The first reed valves (62, 66) are housed in the recesses (31a, 41a). The first cylinder (31, 41) has vane housing holes (33, 43) formed therein, in which the vanes (36, 46) of the first piston (34, 44) are housed. The recesses (31a, 41a) extend radially inward toward the vane housing holes (33, 43) of the first cylinder (31, 41), A rotary compressor in which the directions in which the lateral passages (31e, 41e) and the recesses (31a, 41a) extend are offset from each other by 5 degrees or more.

2. A rotary compressor to which an injection tube (9c) is connected, Casing (10) and The casing (10) is disposed inside the first cylinder (31, 41) which has first cylinder chambers (S1, S2), In the first cylinder chambers (S1, S2), the first pistons (34, 44) rotate eccentrically, The casing (10) is disposed inside the second cylinder (31, 41) which has second cylinder chambers (S1, S2), In the second cylinder chambers (S1, S2), there are second pistons (34, 44) that rotate eccentrically, A shaft (90) connected to the first piston (34, 44) and the second piston (34, 44), A middle plate (55) is positioned between the first cylinder (31, 41) and the second cylinder (31, 41), The first bearing (50, 56) is positioned on the side opposite the middle plate (55) of the first cylinder (31, 41) and pivotally supports the shaft (90), The second cylinder (31, 41) is positioned on the side opposite the middle plate (55) and comprises a second bearing (50, 56) that pivotally supports the shaft (90), The first cylinder (31, 41), the middle plate (55), and the second cylinder (31, 41) are formed with an injection channel (61) that communicates with the injection tube (9c). The injection channel (61) is The first flow path (61a) connected to the injection tube (9c), A second flow path (61b, 61c) branches off from the first flow path (61a) and communicates with the first cylinder chambers (S1, S2), It has a third flow path (61b, 61c) that branches off from the first flow path (61a) and communicates with the second cylinder chambers (S1, S2), The first bearings (50, 56) are formed with discharge ports (51, 57) for discharging refrigerant from the first cylinder chambers (S1, S2). On the inner circumferential surface of the first cylinder (31, 41), discharge notches (37, 47) are formed that are recessed toward the outer circumferential side, such that the inner space of the discharge notches (37, 47) overlaps the discharge port (51, 57) and the shaft (90) in the axial direction. The second flow path (61b, 61c) is a rotary compressor that communicates with the inner space of the discharge notches (37, 47).

3. In the rotary compressor according to claim 1 or 2, The second flow path (61b, 61c) or the third flow path (61b, 61c) has a fourth flow path (61d) that extends in the axial direction of the shaft (90) and penetrates the middle plate (55), A rotary compressor in which the average diameter of the fourth flow path (61d) is equal to or greater than the average diameter of the first flow path (61a).

4. In the rotary compressor according to claim 1 or 2, A rotary compressor in which the sum of the flow area of ​​the second flow path (61b, 61c) and the flow area of ​​the third flow path (61b, 61c) is equal to or greater than the flow area of ​​the first flow path (61a).

5. In the rotary compressor according to claim 1 or 2, The injection pipe (9c) is further connected to an injection muffler (80), The axial direction of the shaft (90) is vertical. The first bearing (56) is a lower bearing, The second bearing (50) is an upper bearing, A portion of the first flow path (61a) is formed in the first bearing (56), A rotary compressor in which the lower end of the injection muffler (80) is located below the lower end of the second bearing (50).

6. In the rotary compressor according to claim 1 or 2, The first cylinder (31, 41) has an injection opening (31b, 41b) that opens in one axial direction, and also has bolt insertion holes (31c, 41c) that penetrate in the axial direction. The first cylinder (31, 41) is fitted with a first reed valve (62, 66) by bolts (65, 67) so as to be able to open and close the injection opening (31b, 41b), Retaining holes (62a, 66a) are formed on the surfaces of the first reed valve (62, 66) facing the first cylinder (31, 41). The aforementioned bolts (65, 67) are inserted through the bolt insertion holes (31c, 41c) and their ends are fastened to the fastening holes (62a, 66a) in the rotary compressor.

7. In the rotary compressor according to claim 1 or 2, The first cylinder (31, 41) has vane housing holes (33, 43) formed therein, in which the vanes (36, 46) of the first piston (34, 44) are housed. A rotary compressor in which the end of the second flow path (61b, 61c) on the first cylinder chamber (S1, S2) side is inclined toward the vane housing hole (33, 43) toward the radially inward side of the first cylinder (31, 41).

8. In the rotary compressor according to claim 1 or 2, A rotary compressor in which the refrigerant supplied from the injection pipe (9c) to the first cylinder chamber (S1) and the second cylinder chamber (S2) is CO2.

9. A refrigeration apparatus comprising a rotary compressor according to claim 1 or 2.

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