Rotary compressors and refrigeration systems

Abstract

To improve the compression efficiency of rotary compressors. [Solution] In the rotary compressor, the cylinders (31, 41, 231, 241, 331) and the closing members (50, 55, 56, 250, 255, 256, 350, 356) are fixed together by a plurality of bolts (B) extending in the axial direction of the rotating shaft (90). The plurality of bolts (B) include, in an axial view, a first bolt (B1) positioned between the intake pipes (14, 214a, 214b, 314) and the housing section (33, 43) that houses the blades (38, 48), and a second bolt (B2) positioned between the housing section (33, 43) and a virtual line (IL) symmetrical to the center line (AL) of the intake pipes (14, 214a, 214b, 314) with respect to the housing section (33, 43).

Description

Technical Field

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

Background Art

[0002] In a rotary compressor, a structure in which a cylinder having a cylinder chamber inside and a closing member for closing the cylinder chamber are fixed by bolts is known.

[0003] In the hermetic compressor described in Patent Document 1, a cylinder chamber in which a piston eccentrically rotates is defined by having a cylinder, a front head (closing member) disposed on one surface side of the cylinder, and a rear head (closing agent) disposed on the other surface side of the cylinder. In the hermetic compressor described in Patent Document 1, the front head and the rear head are each fixed to the cylinder using bolts so that the strain due to thermal expansion based on the temperature distribution difference of the cylinder becomes substantially the same over the entire circumference of the cylinder surrounding the cylinder chamber.

[0004] In the hermetic compressor described in Patent Document 1, bolts are disposed only on the discharge side in the vicinity of the accommodation hole for accommodating the blade.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] As in the rotary compressor described in Patent Document 1, if bolts are positioned on only one side near the housing hole, the balance of the bolts against axial force becomes uneven. As a result, the gap between the closure member and the blades and piston becomes narrower in areas where the axial force is strong, while it becomes wider in areas where the axial force is weaker, potentially resulting in a gap that is not of an appropriate size. The gap between the closure member and the blades and piston affects the compression efficiency. Therefore, from the standpoint of improving compression efficiency, conventional rotary compressors have room for improvement.

[0007] The purpose of this disclosure is to improve the compression efficiency of rotary compressors. [Means for solving the problem]

[0008] A first aspect of the technology disclosed herein relates to a rotary compressor. The rotary compressor comprises cylinders (31, 41, 231, 241, 331) having cylinder chambers (S1, S2) inside, pistons (35, 45) that revolve along the inner surface of the cylinder chambers (S1, S2), a rotating shaft (90) that rotates the pistons (35, 45), blades (38, 48) that divide the cylinder chambers (S1, S2) into intake spaces (71, 75) and discharge spaces (72, 76), closing members (50, 55, 56, 250, 255, 256, 350, 356) that close the axial ends of the rotating shaft (90) in the cylinder chambers (S1, S2), and intake pipes (14, 214a, 214b, 314) that supply refrigerant to the intake spaces (71, 75), and The cylinders (31, 41, 231, 241, 331) and the closing members (50, 55, 56, 250, 255, 256, 350, 356) are fixed by a plurality of bolts (B) extending in the axial direction of the rotating shaft (90). The plurality of bolts (B) include, in an axial view, a first bolt (B1) positioned between the suction pipes (14, 214a, 214b, 314) and the housing section (33, 43) that houses the blades (38, 48), and a second bolt (B2) positioned between the housing section (33, 43) and a virtual line (IL) symmetrical with respect to the center line (AL) of the suction pipes (14, 214a, 214b, 314) with respect to the housing section (33, 43).

[0009] In the first embodiment, the first bolt (B1) and the second bolt (B2) are positioned on opposite sides of the housing (33, 34) in the vicinity of the housing (33, 43), so that the axial force of the bolt (B) in the vicinity of the housing (33, 43) can be balanced, and the compression efficiency can be improved.

[0010] A second aspect of the technology disclosed herein is that, in the first aspect, the plurality of bolts (B) include a third bolt (B3) located in an axial view on the side of the intake pipes (14, 214a, 214b, 314) that is closer to the intake pipes (14, 214a, 214b, 314) than the housing (33, 43), and positioned to sandwich the first bolt (B1) and the intake pipes (14, 214a, 214b, 314).

[0011] In the second embodiment, the distance between the first bolt (B1) and the second bolt (B2) can be made approximately the same as the distance between the first bolt (B1) and the third bolt (B3). This allows the rotary compressor to balance the axial force of the bolts (B) near the blades (38, 48), thereby improving compression efficiency.

[0012] A third aspect of the technology disclosed herein is, in the first or second aspect, in an axial view, the first distance (D1) from the center (X) of the rotation axis (90) to the position of the housing (33,43) furthest from the center (X) of the rotation axis (90) is greater than the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1), and in an axial view, the first distance (D1) is greater than the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2).

[0013] In the third embodiment, the first bolt (B1) and the second bolt (B2) can be positioned closer to the cylinder chambers (S1, S2). This allows the rotary compressor to have an appropriate gap between the closing members (50, 55, 56, 250, 255, 256, 350, 356) in the cylinder chambers (S1, S2) and the blades (38, 48) and pistons (35, 45), thereby improving compression efficiency.

[0014] A fourth aspect of the technology disclosed herein is that, in any one of the first to third aspects, the first bolt (B1) and the second bolt (B2) are arranged symmetrically in an axial view, with respect to a line of symmetry extending in the direction in which the blade (38, 48) extends when the piston (35, 45) is at top dead center.

[0015] In the fourth embodiment, the distance from the first bolt (B1) to the blade (38, 48) is equal to the distance from the second bolt (B2) to the blade (38, 48), making it easier to balance the axial force of the bolt (B) near the blade (38, 48). As a result, the rotary compressor can make the gap between the closing members (50, 55, 56, 250, 255, 256, 350, 356) in the cylinder chambers (S1, S2) and the blades (38, 48) and pistons (35, 45) to an appropriate size, thereby improving compression efficiency.

[0016] A fifth aspect of the technology disclosed herein is that, in any one of the first to third aspects, in an axial view, the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1) is longer than the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2).

[0017] In the fifth embodiment, the first bolt (B1) can be separated from the cylinder chambers (S1, S2), thereby reducing the amount of deformation due to the axial force of the bolt in the intake side portion of the cylinders (31, 41, 231, 241, 331). As a result, the rotary compressor can maintain an appropriate gap between the closing members (50, 55, 56, 250, 255, 256, 350, 356) and the pistons (35, 45) and the pistons (35, 45), thereby suppressing seizure.

[0018] A sixth aspect of the technology disclosed herein is that, in any one of the first to third aspects, in an axial view, the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2) is longer than the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1).

[0019] In the sixth embodiment, the second bolt (B2) can be separated from the cylinder chambers (S1, S2), thereby reducing the amount of deformation due to the axial force of the bolt in the discharge-side portion of the cylinders (31, 41, 231, 241, 331). As a result, the rotary compressor can maintain an appropriate gap between the closing members (50, 55, 56, 250, 255, 256, 350, 356) and the pistons (35, 45) and suppress seizure.

[0020] A seventh aspect of the technology disclosed herein is, in any one of the first to sixth aspects, the suction tube (14, 214a, 214b, 314) is positioned in the occluding member (50, 55, 56, 250, 255, 256, 350, 356), and the cylinder (31, 41, 231, 241, 331) has suction ports (17, 18) that supply refrigerant supplied from the suction tube (14, 214a, 214b, 314) to the suction space (71, 75), and in an axial view, the suction ports (17, 18) extend closer to the housing (33, 43) than the suction tube (14, 214a, 214b, 314) and inclined with respect to the insertion direction of the suction tube (14, 214a, 214b, 314).

[0021] In the seventh embodiment, the rotary compressor can achieve high compression efficiency because the refrigerant supply position is close to top dead center.

[0022] An eighth aspect of the technology disclosed herein is that, in any one of the first to seventh aspects, the refrigerant is carbon dioxide.

[0023] In the eighth embodiment, since carbon dioxide, which has a relatively low density, is used as the refrigerant, the discharge space (72, 76) tends to become high pressure. The rotary compressor allows for an appropriate size of gap between the occluding members (50, 55, 56, 250, 255, 256, 350, 356) and the blades (38, 48) and pistons (35, 45), thus improving compression efficiency even when using carbon dioxide as the refrigerant.

[0024] The ninth aspect of the technology disclosed herein targets a refrigeration device. The refrigeration device includes the rotary compressor (1) described in any one of the first to eighth aspects.

Brief Description of the Drawings

[0025] [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 longitudinal sectional view of the rotary compressor. [Figure 3] FIG. 3 is a cross-sectional view of the first cylinder. [Figure 4] FIG. 4 is a cross-sectional view of the second cylinder. [Figure 5] FIG. 5 is a cross-sectional view taken along line IV-IV of FIG. 3. [Figure 6] FIG. 6 is a view of the rear head seen from the axial internal space side. [Figure 7] FIG. 7 is a view showing the operation of the compression mechanism. [Figure 8] FIG. 8 is a view showing the positional relationship of the bolts. [Figure 9] FIG. 9 is a view showing the distance relationship of the bolts. [Figure 10] FIG. 10 is a view showing the positional relationship of the bolts of the rotary compressor according to Modification 1. [Figure 11] FIG. 11 is a view showing the positional relationship of the bolts of the rotary compressor according to Modification 2. [[ID=,40]] [Figure 12] FIG. 12 is a longitudinal sectional view of a rotary compressor having two suction pipes. [Figure 13] FIG. 13 is a longitudinal sectional view of a rotary compressor having a single-cylinder compression mechanism.

Embodiments for Carrying Out the Invention

[0026] 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 rotation axis extends, "radial direction" refers to the direction radiating from the rotation axis, and "circumferential direction" refers to the circumferential direction centered on the rotation axis. 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.

[0027] (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 air-conditions 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 expansion valve (5), and an economizer heat exchanger (4b). 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).

[0028] The compressor (1) in this embodiment is of the type in which blades (38, 48) rotate eccentrically while connected to specific positions on the outer circumference of pistons (35, 45), and is a so-called swing type in which the blades (38, 48) and pistons (35, 45) are integrally formed. 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).

[0029] 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.

[0030] 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).

[0031] 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).

[0032] 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).

[0033] 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 piping (9c). 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 piping (9c) as refrigerant at an intermediate pressure.

[0034] 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).

[0035] 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.

[0036] (2) Rotary compressor As shown in Figure 2, the compressor (1) comprises a sealed container (10), an electric motor (20), and a compression mechanism (30). The electric motor (20) and the compression mechanism (30) are housed within the sealed container (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 sealed container (10), and the internal space (R) becomes high-pressure.

[0037] (2-1) Rotary Compressor The sealed container (10) is formed in an elongated shape. Specifically, the sealed container (10) comprises a cylindrical body (11) extending vertically, 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).

[0038] (2-2) Electric motor The electric motor (20) is housed in a sealed container (10). The electric motor (20) drives the compression mechanism (30). Within the electric motor (20), it 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).

[0039] (2-3) Rotation axis The rotating shaft (90) is positioned to extend vertically within the sealed container (10). The rotating shaft (90) is driven by an electric motor (20). The upper part of the rotating shaft (90) is connected to the rotor (22) of the electric motor (20).

[0040] The lower part of the rotating shaft (90) has, in order 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.

[0041] The first eccentric portion (91) and the second eccentric portion (92) are eccentric with respect to the axis of the rotation 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 rotation center axis of the rotation shaft (90) is 180° different from the eccentric direction of the second eccentric portion (92) with respect to the rotation center axis of the rotation shaft (90).

[0042] 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).

[0043] (2-4) Compression mechanism As shown in Figure 2, the compression mechanism (30) is housed within a sealed container (10). The compression mechanism (30) compresses the inhaled refrigerant and discharges it into the internal space (R) of the sealed container (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 positioned on the lower surface of the mounting plate (54). The compression mechanism (30) has two cylinders. The compression mechanism (30) comprises a rotating shaft (90), a front head (50), a first cylinder (31), a first piston (35), a first blade (38), a middle plate (55), a second cylinder (41), a second piston (45), a second blade (48), and a rear head (56). The front head (50), first cylinder (31), middle plate (55), second cylinder (41), and rear head (56) are fixed together by a number of bolts, from the first bolt (B1) to the seventh bolt (B7), so as not to move relative to one another. In the following description, when the first bolt (B1) to the seventh bolt (B7) are not distinguished, they will simply be referred to as bolt (B).

[0044] (2-4-1) Cylinder As shown in Figures 2 to 4, the first cylinder (31) and the second cylinder (41) are thick-walled disc-shaped members. The first cylinder (31) and the second cylinder (41) have a cylinder bore (32, 42), a blade housing hole (33, 43), an intake port (17, 18), and an injection passage (6 It has 1, 62), injection ports (63, 64), and multiple insertion holes (81, 82).

[0045] The cylinder bores (32, 42) are circular holes that penetrate the cylinders (31, 41) in the thickness direction. The cylinder bores (32, 42) are formed in the central part of the cylinders (31, 41). The first cylinder bore (32) of the first cylinder (31) houses the first piston (35). The second cylinder bore (42) of the second cylinder (41) houses the second piston (45).

[0046] In the first cylinder (31), a first cylinder chamber (S1) is formed between the wall surface of the first cylinder bore (32) and the first piston (35). In the second cylinder (41), a second cylinder chamber (S2) is formed between the wall surface of the second cylinder bore (42) and the second piston (45).

[0047] The blade housing holes (33, 43) are holes that extend radially outward from the inner circumferential surface of the cylinder (31, 41) (i.e., the outer edge of the cylinder bore (32, 42)). These blade housing holes (33, 43) penetrate the cylinder (31, 41) in the thickness direction. The first blade (38) is housed in the first blade housing hole (33) of the first cylinder (31). The second blade (48) is housed in the second blade housing hole (43) of the second cylinder (41). The blade housing holes (33, 43) are an example of a housing section.

[0048] 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 first blade housing hole (33) in Figure 3. The second cylinder (41) has a second passage (16b) which is part of the intake passage (16). The second passage (16b) penetrates through the thickness direction of the second cylinder (41). The second passage (16b) is located to the right of the second blade housing hole (43) in Figure 4.

[0049] The intake ports (17,18) 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). The second intake port (18) of the second cylinder (41) extends from the second passage (16b) toward the second cylinder chamber (S2). In an axial view, the intake ports (17,18) extend toward the cylinder chambers (S1,S2) such that they are closer to the blade housing holes (33,43) than to the intake passage (16). The intake ports (17,18) extend so as to be inclined with respect to the insertion direction of the intake tube (14).

[0050] The injection passages (61, 62) are passages that supply refrigerant to the cylinder chambers (S1, S2) separately from the intake passage (16). The first injection passage (61) of the first cylinder (31) is located to the left of the first blade housing hole (33) in Figure 3. In other words, the first injection passage (61) of the first cylinder (31) is located on the opposite side of the first blade housing hole (33) from the first passage (16a). The second injection passage (62) of the second cylinder (41) is located to the left of the second blade housing hole (43) in Figure 4. In other words, the second injection passage (62) of the second cylinder (41) is located on the opposite side of the second blade housing hole (43) from the second passage (16b).

[0051] The injection ports (63, 64) extend from the injection passages (61, 62) toward the cylinder chambers (S1, S2). In an axial view, the injection ports (63, 64) extend toward the cylinder chambers (S1, S2) so as to be closer to the blade housing holes (33, 43) than to the injection passages (61, 62).

[0052] The through holes (81, 82) are holes through which the bolt (B) is inserted. There are seven through holes (81, 82). The circumferential arrangement of the second through holes (82) located in the second cylinder (41) corresponds to the circumferential arrangement of the first through holes (81) located in the first cylinder (31). The first through holes (81) and the second through holes (82) overlap in an axial view. The through holes (81, 82) may or may not have screw threads. The detailed arrangement of the through holes (81, 82) will be described later along with the arrangement of the bolt (B).

[0053] In an axial view, the external shape of the cylinder (31,41) is symmetrical with respect to a specific straight line (SL). The specific straight line (SL) will be described later.

[0054] (2-4-2) Piston The first piston (35) is housed within the first cylinder (31). The first piston (35) revolves inside the first cylinder chamber (S1). The first piston (35) is configured to slide against both the front head (50) and the middle plate (55).

[0055] The first piston (35) is formed in an annular shape. The first piston (35) is formed in a slightly thick-walled cylindrical shape. The first eccentric portion (91) of the rotating shaft (90) is inserted through the first piston (35). As the first eccentric portion (91) rotates, the first piston (35) pivots along the inner circumferential surface of the first cylinder chamber (S1) of the first cylinder (31).

[0056] The second piston (45) is identical to the first piston (35) in shape, dimensions, and material. The first piston (35) and the second piston (45) are positioned inverted relative to each other in the vertical direction.

[0057] The second piston (45) is housed within the second cylinder (41). The second piston (45) revolves within the second cylinder chamber (S2). The second piston (45) is configured to slide against both the rear head (56) and the middle plate (55).

[0058] The second piston (45) is formed in an annular shape. The second piston (45) is formed in a slightly thick-walled cylindrical shape. The second eccentric portion (92) of the rotating shaft (90) is inserted through the second piston (45). As the second eccentric portion (92) rotates, the second piston (45) pivots along the inner circumferential surface of the second cylinder chamber (S2) of the second cylinder (41).

[0059] (2-4-3) Blade As shown in Figures 3 and 4, the first blade (38) and the second blade (48) are slightly thick rectangular flat members. The first blade (38) is integrally formed with the first piston (35). The second blade (48) is integrally formed with the second piston (45). The blades (38, 48) extend radially outward from the outer circumferential surface of the pistons (35, 45).

[0060] The first blade (38) fits into the first blade housing hole (33). The first blade (38) is sandwiched from both sides by a pair of first bushes (70) provided on the first cylinder (31). The first blade (38), which is integrated with the first piston (35), is supported by the first cylinder (31) via the first bushes (70) so that it can swing freely and move forward and backward.

[0061] The first blade (38) divides the first cylinder chamber (S1) into a first intake space (71) and a first discharge space (72). The first blade (38) restricts the rotation of the first piston (35) itself when the first piston (35) is rotating. As a result, the first piston (35) rotates along the inner surface of the first cylinder chamber (S1) without rotating.

[0062] The second blade (48) fits into the second blade housing hole (43). The second blade (48) is sandwiched from both sides by a pair of second bushes (74) provided on the second cylinder (41). The second blade (48), which is integrated with the second piston (45), is supported by the second cylinder (41) via these second bushes (74) so ​​that it can swing freely and move forward and backward.

[0063] The second blade (48) divides the second cylinder chamber (S2) into a second intake space (75) and a second discharge space (76). The second blade (48) restricts the rotation of the second piston (45) itself when the second piston (45) is swirling. As a result, the second piston (45) swirls along the inner surface of the second cylinder chamber (S2) without rotating.

[0064] (2-4-4) Front Head As shown in Figure 2, 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.

[0065] 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 2). 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 rotating shaft (90).

[0066] As shown in Figure 5, 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).

[0067] A first discharge valve (53) 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) 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) 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).

[0068] The first main body (50a) has a plurality of fastening holes (83). The fastening holes (83) are holes through which bolts (B) are fastened. The fastening holes (83) are bottomed holes that extend in the axial direction and do not penetrate the first main body (50a). The circumferential arrangement of the fastening holes (83) corresponds to the circumferential arrangement of the insertion holes (81, 82) of the cylinders (31, 41).

[0069] (2-4-5) Middle Plate As shown in Figure 2, the middle plate (55) is sandwiched axially between the first cylinder (31) and the second cylinder (41). The middle plate (55) closes the axial ends of the first cylinder (31) and 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). The middle plate (55) is an example of a closing member of this disclosure.

[0070] A central hole is formed in the middle of the middle plate (55), passing through it axially. The intermediate shaft portion (90b) of the rotating shaft (90) is inserted through the central hole.

[0071] 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).

[0072] Although detailed illustrations are omitted, the middle plate (55) has a passage that connects the first injection passage (61) and the second injection passage (62).

[0073] The middle plate (55) has a plurality of intermediate insertion holes (84). The intermediate insertion holes (84) are holes through which bolts (B) are inserted. The intermediate insertion holes (84) penetrate the middle plate (55) in the thickness direction. The circumferential arrangement of the intermediate insertion holes (84) corresponds to the circumferential arrangement of the insertion holes (81, 82) of the cylinders (31, 41). The intermediate insertion holes (84) may or may not have screw threads.

[0074] (2-4-6) Rear Head As shown in Figure 2, 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. The rear head (56) comprises a second main body (56a), a lower bearing portion (56b), and an expansion portion (56c). The second main body (56a) and the lower bearing portion (56b) are a single component.

[0075] As shown in Figure 6, the second main body (56a) is formed in a generally circular, thick plate shape. The lower surface of the second main body (56a) is in close contact with the lower end surface of the second cylinder (41). The lower bearing portion (56b) is formed in a cylindrical shape extending from the second main body (56a) to the opposite side of the second cylinder (41) (the lower side in Figure 2). The lower bearing portion (56b) is located in the center of the second main body (56a). The lower bearing portion (56b) rotatably supports the lower shaft portion (90c) of the rotating shaft (90).

[0076] The expansion portion (56c) extends radially outward from the second main body portion (56a). The expansion portion (56c) has a first insertion hole (19) into which the suction tube (14) is inserted, and a second insertion hole (60) into which an injection tube (not shown) is inserted. The first insertion hole (19) and the second insertion hole (60) each extend radially.

[0077] 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).

[0078] A lower injection passage (65) extends from the second insertion hole (60). The lower injection passage (65) extends upward along the axial direction from the tip of the second insertion hole (60). The upper end of the lower injection passage (65) communicates with the second injection passage (62).

[0079] As shown in Figures 5 and 6, the second main body (56a) has a second discharge port (57). The second discharge port (57) penetrates the second main body (56a) in the thickness direction. The second discharge port (57) connects the internal space (R) and the second discharge space (76).

[0080] 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 refrigerant pressure in the second discharge space (76) 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 (76) 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).

[0081] The rear head (56) has a plurality of lower through holes (85). The lower through holes (85) are holes through which bolts (B) are inserted. The lower through holes (85) penetrate the rear head (56) in the axial direction. The circumferential arrangement of the lower through holes (85) corresponds to the circumferential arrangement of the through holes (81, 82) of the cylinders (31, 41). The lower through holes (85) may or may not have screw threads.

[0082] (3) Operating Next, the operation of the compressor (1) will be explained with reference to Figure 7. The refrigerant compression operation by the first cylinder (31) and the first piston (35) and the refrigerant compression operation by the second cylinder (41) and the second piston (45) 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 (35) will be described in detail, while the refrigerant compression operation by the second cylinder (41) and the first piston (35) will not be explained.

[0083] In the compressor (1), when the electric motor (20) is started and the rotor (22) is rotated, the rotating shaft (90) rotates and the first eccentric part (91) rotates eccentrically. As the first eccentric part (91) rotates eccentrically, the first piston (35) rotates along the inner surface of the first cylinder (31) while restricting its rotation.

[0084] The suction stroke for drawing refrigerant into the first cylinder chamber (S1) will now be described. When the rotation angle of the rotating shaft (90) rotates slightly from the state of 0° (state in Figure 7(A)), the contact point between the first piston (35) and the first cylinder (31) passes the inner circumference end of the first suction port (17). At this time, the suction of refrigerant into the first suction space (71) begins.

[0085] 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 rotating 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 7(B) to (H)). This refrigerant suction stroke continues until the rotation angle of the rotating shaft (90) reaches 360°, after which the process transitions to the discharge stroke.

[0086] The discharge stroke, in which the refrigerant is compressed and discharged in the first cylinder chamber (S1), will now be described. When the rotation angle of the rotating shaft (90) rotates slightly from the state of 0° (state in Figure 7(A)), the contact point between the first piston (35) 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.

[0087] 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 rotating 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.

[0088] 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 sealed container (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 rotating shaft (90) reaches 360°, after which the process transitions to the suction stroke.

[0089] In this manner, the intake stroke and discharge stroke are repeated in the first cylinder chamber (S1). In the second cylinder chamber (S2), the intake stroke and discharge stroke are repeated with a 180° phase difference relative to the first cylinder chamber (S1). As a result, the compressor (1) continuously compresses the refrigerant.

[0090] (4) Bolt placement Near bolt (B), the axial force of bolt (B) acts strongly. Near bolt (B), the axial gaps between the front head (50) and the first piston (35) and the first blade (38), the middle plate (55) and the first piston (35) and the first blade (38), the middle plate (55) and the second piston (45) and the second blade (48), and the rear head (56) and the second piston (45) and the second blade (48) (hereinafter collectively referred to as the axial gap) tend to be narrow. On the other hand, at positions far from bolt (B), the axial force of bolt (B) does not act as strongly, and these axial gaps tend to be larger.

[0091] Axial clearance affects compression efficiency. In particular, the axial clearance between the blades (38, 48) that separate the intake space (71, 75) and the discharge space (72, 76), and the front head (50), middle plate (55), and rear head (56) is likely to affect compression efficiency.

[0092] In this embodiment, the compressor (1) has multiple bolts (B) arranged near the blades (38, 48) taking into consideration the balance of the axial force of the bolts (B). The arrangement of the bolts (B) will be described in detail below with reference to Figures 8 and 9. Since the arrangement of the bolts (B) is the same for the first cylinder (31) and the second cylinder (41), the following description will be based on the first cylinder (31).

[0093] As shown in Figure 8, the group of bolts (B) includes seven bolts, from the first bolt (B1) to the seventh bolt (B7). Each of the group of bolts (B) has the same configuration, with the same diameter and shaft length.

[0094] Around the first blade housing hole (33), a first bolt (B1) is positioned on the circumferential side of the intake port (17), and a second bolt (B2) is positioned on the circumferential side of the discharge port (51). Specifically, the first bolt (B1) is positioned between the intake pipe (14) and the first blade housing hole (33) in an axial view. The second bolt (B2) is positioned between the first blade housing hole (33) and a virtual line (IL) that is symmetrical with respect to the center line (AL) of the intake pipe (14) with respect to the first blade housing hole (33) in an axial view. In this embodiment, in an axial view, the center line (AL) and the virtual line (IL) are symmetric with respect to a specific line (SL) connecting the furthest point (33a) of the first blade housing hole (33) that is furthest from the center (X) of the rotation axis (90) and the center (X) of the rotation axis (90). The direction in which the specific straight line (SL) extends coincides with the direction in which the first blade (38) extends when the first piston (35) is at top dead center. The specific straight line (SL) corresponds to the straight line extending in the direction in which the first blade (38) extends when the first piston (35) is at top dead center. The specific straight line (SL) is also the line of symmetry in the external shape of the first cylinder (31).

[0095] In an axial view, the first bolt (B1) and the second bolt (B2) are positioned symmetrically with respect to a line extending in the direction in which the first blade (38) extends when the first piston (35) is at top dead center. In other words, in an axial view, the first bolt (B1) and the second bolt (B2) are positioned symmetrically with respect to a specific line (SL) passing through the center (X) of the axis of rotation (90). When the first piston (35) is at top dead center, the shortest distance from the center (BC1) of the first bolt (B1) to the first blade (38) is the same as the shortest distance from the center (BC2) of the second bolt (B2) to the first blade (38). The shortest distance from the center (BC1) of the first bolt (B1) to the first cylinder chamber (S1) is the same as the shortest distance from the center (BC2) of the second bolt (B2) to the first cylinder chamber (S1).

[0096] As shown in Figure 9, in an axial view, the first distance (D1) from the center (X) of the rotation axis (90) to the furthest point (33a) of the first blade housing hole (33) is greater than the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1). Also in an axial view, the first distance (D1) is greater than the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2). In this embodiment, the second distance (D2) and the third distance (D3) are the same.

[0097] The third bolt (B3) to the seventh bolt (B7) are arranged in the order of third bolt (B3), fourth bolt (B4), fifth bolt (B5), sixth bolt (B6), and seventh bolt (B7) when viewed from the axial upper side, starting from the first bolt (B1). As shown in Figure 8, the third bolt (B3) is located on the suction pipe (14) side of the first blade housing hole (33) in an axial view, and is positioned so as to sandwich the first bolt (B1) and the suction pipe (14). The seventh bolt (B7) is located further from the first blade housing hole (33) than the dashed line (IL).

[0098] The first bolt (B1) to the seventh bolt (B7) are arranged at relatively equal intervals, while avoiding the suction pipe (14), injection pipe, and discharge valves (53, 59). As shown in Figure 9, the distance between the center of the first bolt (B1) (BC1) and the center of the second bolt (B2) (BC2) is defined as the first interval (W1), the distance between the center of the second bolt (B2) (BC2) and the center of the third bolt (B3) (BC3) is defined as the second interval (W2), the distance between the center of the third bolt (B3) (BC3) and the center of the fourth bolt (B4) (BC4) is defined as the third interval (W3), and the distance between the center of the fourth bolt (B4) (BC4) and the fifth bolt The distance between the center of bolt (B5) and the center of bolt (BC5) is defined as the fourth interval (W4), the distance between the center of bolt (B5) and the center of bolt (BC6) of bolt (B6) is defined as the fifth interval (W5), the distance between the center of bolt (B6) and the center of bolt (BC7) of bolt (B7) is defined as the sixth interval (W6), and the distance between the center of bolt (B7) and the center of bolt (BC2) of bolt (B2) is defined as the seventh interval (W7). The fifth interval (W5) is the narrowest interval, and the seventh interval (W7) is the widest interval. The ratio of the other intervals (W2, W3, W4, W5, W6, W7) to the first interval (W1) is in the range of 0.85 to 1.50. Specifically, the ratio of the second interval (W2) to the first interval (W1) is 0.96. The ratio of the third interval (W3) to the first interval (W1) is 0.97. The ratio of the fourth interval (W4) to the first interval (W1) is 1.00. The ratio of the fifth interval (W5) to the first interval (W1) is 0.89. The ratio of the sixth interval (W6) to the first interval (W1) is 1.14. The ratio of the seventh interval (W7) to the first interval (W1) is 1.43. The ratio of the widest interval, the seventh interval (W7), to the narrowest interval, the fifth interval (W5), is less than 2.00, specifically 1.61.

[0099] (5) Effects of the embodiment In the rotary compressor (1) according to this embodiment, the cylinders (31, 41), the front head (50), the middle plate (55), and the rear head (56) are fixed together by a plurality of bolts (B) extending in the axial direction of the rotating shaft (90). The plurality of bolts (B) include, in an axial view, a first bolt (B1) positioned between the suction pipe (14) and the blade housing holes (33, 43) that house the blades (38, 48), and a second bolt (B2) positioned between a virtual line (IL) symmetrical with respect to the center line (AL) of the suction pipe (14) with respect to the blade housing holes (33, 43) and the blade housing holes (33, 43). In the vicinity of the blade housing holes (33, 43), the first bolt (B1) and the second bolt (B2) are positioned on opposite sides of the blade housing holes (33, 43), thus balancing the axial force of the bolts (B) in the vicinity of the blade housing holes (33, 43). As a result, the rotary compressor (1) according to this embodiment can have an appropriate axial clearance between the front head (50), middle plate (55), and rear head (56) and the blades (38, 48) and pistons (35, 45), thereby improving compression efficiency.

[0100] In the rotary compressor (1) according to this embodiment, in an axial view, the first distance (D1) from the center (X) of the rotation axis (90) to the position of the blade housing hole (33, 43) furthest from the center (X) of the rotation axis (90) is greater than the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1), and in an axial view, the first distance (D1) is greater than the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2). The first bolt (B1) and the second bolt (B2) can be positioned closer to the cylinder chambers (S1, S2). As a result, the rotary compressor (1) according to this embodiment can have an appropriate axial clearance between the front head (50), middle plate (55), and rear head (56) in the cylinder chambers (S1, S2) and the blades (38, 48) and pistons (35, 45), thereby improving compression efficiency.

[0101] In the rotary compressor (1) according to this embodiment, the first bolt (B1) and the second bolt (B2) are arranged symmetrically with respect to a specific straight line (SL) extending in the direction in which the blades (38, 48) extend when the pistons (35, 45) are at top dead center. When the first piston (35) is at top dead center, the shortest distance from the center (BC1) of the first bolt (B1) to the blades (38, 48) is the same as the shortest distance from the center (BC2) of the second bolt (B2) to the blades (38, 48). As a result, the rotary compressor (1) according to this embodiment can easily balance the axial force of the bolts (B) in the vicinity of the blades (38, 48), thereby improving compression efficiency.

[0102] In the rotary compressor (1) according to this embodiment, the specific straight line (SL) is a straight line passing through the center (X) of the rotation axis (90). As a result, the second distance (D2) and the third distance (D3) are of the same magnitude, so the shortest distance from the center (BC1) of the first bolt (B1) to the cylinder chamber (S1, S2) is the same as the shortest distance from the center (BC2) of the second bolt (B2) to the cylinder chamber (S1, S2). As a result, the influence of the axial force of the first bolt (B1) on the cylinder chamber (S1, S2) and the influence of the axial force of the second bolt (B2) are equal. In the rotary compressor (1) according to this embodiment, it is possible to easily balance the axial force of the bolts (B) near the blades (38, 48) in the cylinder chamber (S1, S2), and the compression efficiency can be improved.

[0103] In the rotary compressor (1) according to this embodiment, the plurality of bolts (B) include a third bolt (B3) that is located on the suction pipe (14) side of the blade housing holes (33, 43) in an axial view and is positioned to sandwich the first bolt (B1) and the suction pipe (14). The second bolt (B2) is positioned with respect to the first bolt (B1) with respect to the blade housing holes (33, 43), and the third bolt (B3) is positioned with respect to the first bolt (B1) with respect to the suction pipe (14). This makes it possible to make the first distance (W1) between the center (BC1) of the first bolt (B1) and the center (BC2) of the second bolt (B2) and the second distance (W2) between the center (BC1) of the first bolt (B1) and the center (BC3) of the third bolt (B3) approximately the same. The rotary compressor (1) according to this embodiment can balance the axial force of the bolt (B) in the vicinity of the blades (38, 48), thereby improving compression efficiency.

[0104] In the rotary compressor (1) according to this embodiment, the ratio of the distance between the centers of adjacent bolts (B) in the circumferential direction to the first distance (W1) between the center (BC1) of the first bolt (B1) and the center (BC2) of the second bolt (B2) is within the range of 0.85 to 1.50. Since the distance between the centers of adjacent bolts (B) in the circumferential direction can be made to be approximately the same, the amount of deformation due to the axial force of the bolts (B) can be reduced for the entire cylinder (31, 41). As a result, the rotary compressor (1) according to this embodiment can have an appropriate axial clearance between the front head (50), middle plate (55), and rear head (56) and the blades (38, 48) and pistons (35, 45), thereby improving compression efficiency.

[0105] In the rotary compressor (1) according to this embodiment, the suction ports (17, 18) extend closer to the blade housing holes (33, 43) than the suction pipe (14) and are inclined with respect to the insertion direction of the suction pipe (14). As a result, the refrigerant supply position in the rotary compressor (1) according to this embodiment is closer to top dead center, thereby increasing the compression efficiency.

[0106] (6) Variant The above embodiment may also be modified as follows. In the following description, we will primarily explain the differences from the above embodiment.

[0107] (6-1) Torture 1 In the rotary compressor (1) of Modification 1, the positional relationship between the first bolt (B1) and the second bolt (B2) differs from that of the previously described embodiment. Specifically, as shown in Figure 10, in the rotary compressor (1) of Modification 1, the first bolt (B1) is positioned radially outward from the second bolt (B2). As with the previously described embodiment, the arrangement of bolts (B) is the same for the first cylinder (31) and the second cylinder (41), so the following description will be based on the first cylinder (31).

[0108] Because the first bolt (B1) is positioned as described above, the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1) is different from the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2). Specifically, the second distance (D2) is longer than the third distance (D3). Therefore, the shortest distance from the first bolt (B1) to the first cylinder chamber (S1) is longer than the shortest distance from the second bolt (B2) to the first cylinder chamber (S1).

[0109] The shortest distance (SD1) from the center (BC1) of the first bolt (B1) to a specific line (SL) is the same as the shortest distance (SD2) from the center (BC2) of the second bolt (B2) to the specific line (SL). Therefore, when the first piston (35) is at top dead center, the shortest distance from the center (BC1) of the first bolt (B1) to the first blade (38) is the same as the shortest distance from the center (BC2) of the second bolt (B2) to the first blade (38).

[0110] In the rotary compressor (1) according to Modification 1, the parts of the cylinders (31, 41) around the intake ports (17, 18) are cooled by the refrigerant and undergo thermal contraction. When the cylinders (31, 41) undergo thermal contraction, the gaps between the rear head (50), middle plate (55), and rear head (56) and the pistons (35, 45) and blades (38, 48) become smaller, which may cause seizure. In the rotary compressor (1) according to Modification 1, the first bolt (B1) can be separated from the cylinder chambers (S1, S2), and the amount of deformation due to the axial force of the bolt in the intake side part of the cylinders (31, 41, 231, 241, 331) can be reduced. As a result, the rotary compressor (1) according to Modification 1 can have an appropriate gap between the front head (50), middle plate (55), and rear head (56) in the cylinder chambers (S1, S2) and the pistons (35, 45) and blades (38, 48), thereby suppressing seizure.

[0111] In the rotary compressor (1) according to Modification 1, the shortest distance from the center (BC1) of the first bolt (B1) to the blade (38, 48) and the shortest distance from the center (BC2) of the second bolt (B2) to the blade (38, 48) are the same when the pistons (35, 45) are at top dead center. As a result, the rotary compressor (1) according to this embodiment can easily balance the axial force of the bolts (B) near the blades (38, 48), thereby improving compression efficiency.

[0112] (6-2) Modification 2 In the rotary compressor (1) of Modification 2, the positional relationship between the first bolt (B1) and the second bolt (B2) differs from that of the previously described embodiment. Specifically, as shown in Figure 11, in the rotary compressor (1) of Modification 2, the second bolt (B2) is positioned radially outward from the first bolt (B1). As with the previous embodiment, the arrangement of bolts (B) is the same for the first cylinder (31) and the second cylinder (41), so the following description will be based on the first cylinder (31).

[0113] Because the second bolt (B2) is positioned as described above, the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1) is different from the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2). Specifically, the third distance (D3) is longer than the second distance (D2). Therefore, the shortest distance from the second bolt (B2) to the first cylinder chamber (S1) is longer than the shortest distance from the first bolt (B1) to the first cylinder chamber (S1).

[0114] The shortest distance (SD1) from the center (BC1) of the first bolt (B1) to a specific line (SL) is the same as the shortest distance (SD2) from the center (BC2) of the second bolt (B2) to the specific line (SL). Therefore, when the first piston (35) is at top dead center, the shortest distance from the center (BC1) of the first bolt (B1) to the first blade (38) is the same as the shortest distance from the center (BC2) of the second bolt (B2) to the first blade (38).

[0115] In the rotary compressor (1) according to Modification 2, the front head (50), middle plate (55), and rear head (56) undergo thermal expansion around the discharge ports (51, 56) of the cylinders (31, 41) due to the compressed, high-temperature refrigerant. When these expand, the gap between the front head (50), middle plate (55), and rear head (56) and the pistons (35, 45) and blades (38, 48) becomes smaller, which may cause seizure. In the rotary compressor (1) according to Modification 2, the second bolt (B2) can be moved away from the cylinder chambers (S1, S2), and the amount of deformation due to the axial force of the bolt in the discharge-side portion of the cylinders (31, 41, 231, 241, 331) can be reduced. As a result, the rotary compressor (1) according to Modification 1 can have an appropriate gap between the front head (50), middle plate (55), and rear head (56) in the cylinder chambers (S1, S2) and the pistons (35, 45) and blades (38, 48), thereby suppressing seizure.

[0116] In the rotary compressor (1) according to Modification 2, the shortest distance from the center (BC1) of the first bolt (B1) to the blade (38, 48) and the shortest distance from the center (BC2) of the second bolt (B2) to the blade (38, 48) are the same when the pistons (35, 45) are at top dead center. As a result, the rotary compressor (1) according to this embodiment can easily balance the axial force of the bolts (B) near the blades (38, 48), thereby improving compression efficiency.

[0117] <Other Embodiments> The suction tube (14) may be located in any of the front head (50), middle plate (55), first cylinder (31), or second cylinder (41).

[0118] As shown in Figure 12, the compression mechanism (230) of the rotary compressor (201) may have two suction pipes, a first suction pipe (214a) and a second suction pipe (214b). In Figure 12, the first suction pipe (214a) is connected to the first suction port (217) of the first cylinder (231). The second suction pipe (214b) is connected to the second suction port (218) of the second cylinder (241). In the example shown in Figure 12, there is no suction passage as in the above embodiment, and the suction ports (217, 218) are directly connected to the suction pipes (214a, 214b). The first suction pipe (214a) may be located in the front head (250), and the second suction pipe (214b) may be located in the rear head (256). One or both of the first inhalation tube (214a) and the second inhalation tube (214b) may be located in the middle plate (255). In these cases, an inhalation passage must be provided.

[0119] As shown in Figure 13, the compression mechanism (330) of the rotary compressor (301) may be a single-cylinder compressor having one piston (35) and one eccentric section (91). In the example shown in Figure 13, the intake pipe (314) is inserted into the insertion hole (319) of the rear head (356). The intake pipe (314) is connected to the intake port (317) via an intake passage (316) formed in the rear head (356) and the cylinder (331). The intake pipe (314) may be located in either the front head (350) or the cylinder (331).

[0120] The rotary compressor (1) may be of the so-called rolling piston type, in which a separate blade contacts the piston while the piston rotates eccentrically, or it may be of the so-called hinge vane type, in which the tip of the blade is rotatably fitted into a recess on the outer surface of the piston while the piston rotates eccentrically.

[0121] 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.

[0122] 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]

[0123] As described above, this disclosure is useful for rotary compressors. [Explanation of Symbols]

[0124] 1. Rotary Compressor 31. First cylinder 35 First Piston 38 First Blade 41 Second Cylinder 45. Second piston 48. Second Blade 50 Front head (closing member) 55 Middle plate (closing member) 56 Rear head (closing member) 201 Rotary Compressor 231 First Cylinder 241 Second Cylinder 250 Front head (closing member) 255 Middle plate (closure member) 256 Rear head (closing member) 301 Rotary Compressor 331 Cylinder 350 Front head (closing member) 356 Rear head (closing member) B1 1st bolt BC1 Center of the first bolt B2 2nd bolt BC2 Center of the second bolt B3 Third bolt AL inhalation tube centerline IL virtual line X: Center of the rotation axis

Claims

1. Cylinders (31, 41, 231, 241, 331) having internal cylinder chambers (S1, S2), A piston (35, 45) that rotates along the inner surface of the cylinder chamber (S1, S2), The rotating shaft (90) that rotates the pistons (35, 45), Blades (38, 48) that divide the cylinder chambers (S1, S2) into intake spaces (71, 75) and discharge spaces (72, 76), A closing member (50, 55, 56, 250, 255, 256, 350, 356) that closes the axial end of the rotating shaft (90) in the cylinder chamber (S1, S2), The system includes suction pipes (14, 214a, 214b, 314) that supply refrigerant to the aforementioned suction spaces (71, 75), The cylinders (31, 41, 231, 241, 331) and the closing members (50, 55, 56, 250, 255, 256, 350, 356) are fixed together by a plurality of bolts (B) extending in the axial direction of the rotating shaft (90). The multiple bolts (B) are, In an axial view, a first bolt (B1) is positioned between the suction pipe (14, 214a, 214b, 314) and the housing section (33, 43) that houses the blade (38, 48), In an axial view, a virtual line (IL) symmetrical to the center line (AL) of the suction pipe (14, 214a, 214b, 314) with respect to the housing portion (33, 43), and a second bolt (B2) positioned between the housing portion (33, 43), A rotary compressor, including [a specific component].

2. In the rotary compressor according to claim 1, A rotary compressor in which a plurality of bolts (B) include a third bolt (B3) that is located on the suction pipe (14) side of the housing portion (33, 43) in an axial view and is positioned to sandwich the first bolt (B1) and the suction pipe (14, 214a, 214b, 314).

3. In the rotary compressor according to claim 1, In an axial view, the first distance (D1) from the center (X) of the rotation axis (90) to the position of the housing portion (33,43) furthest from the center (X) of the rotation axis (90) is greater than the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1). A rotary compressor in which, in an axial view, the first distance (D1) is greater than the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2).

4. In the rotary compressor according to claim 1, In an axial view, the first bolt (B1) and the second bolt (B2) are arranged symmetrically with respect to a straight line extending in the direction in which the blades (38, 48) extend when the pistons (35, 45) are at top dead center, in a rotary compressor.

5. In the rotary compressor according to any one of claims 1 to 3, A rotary compressor in which, in an axial view, the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1) is longer than the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2).

6. In the rotary compressor according to any one of claims 1 to 3, A rotary compressor in which, in an axial view, the third distance (D3) from the center (X) of the rotation axis (90) to the center (BC2) of the second bolt (B2) is longer than the second distance (D2) from the center (X) of the rotation axis (90) to the center (BC1) of the first bolt (B1).

7. In the rotary compressor according to any one of claims 1 to 4, The suction tubes (14, 214a, 214b, 314) are arranged in the occluding members (50, 55, 56, 250, 255, 256, 350, 356), The cylinders (31, 41, 231, 241, 331) have suction ports (17, 18) that supply refrigerant supplied from the suction pipes (14, 214a, 214b, 314) to the suction space (71, 75), A rotary compressor in which, in an axial view, the intake ports (17, 18) extend closer to the housing (33, 43) than the intake pipes (14, 214a, 214b, 314) and are inclined with respect to the insertion direction of the intake pipes (14, 214a, 214b, 314).

8. In the rotary compressor according to any one of claims 1 to 4, The rotary compressor uses carbon dioxide as the refrigerant.

9. A refrigeration system comprising a rotary compressor (1) according to any one of claims 1 to 4.

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