Rotary compressor and refrigeration device

Abstract

A first head (31) has a first discharge port (49). A first discharge valve (60) opens and closes the first discharge port (49). A first fastener (61) fixes a base end portion of the first discharge valve (60) to the first head (31). A cylinder (70) has a vane chamber (73) configured to house a vane (77), the vane chamber (73) having a first center line (L1). The first head (31) is divided into a first region on the side of the first center line (L1) corresponding to the suction space and a second region on the side of the first center line (L1) corresponding to the discharge space when viewed from a first direction. The first fastener (61) is disposed in the first region of the first head (31).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a rotary compressor and a refrigeration apparatus. 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 a compression chamber. There are various types of rotary compressors, such as a so-called rolling piston compressor in which a roller eccentrically rotates while a vane separate from the roller abuts on the roller, a so-called swing compressor in which a vane integrally formed with the roller oscillates with the eccentric rotation of the roller, and a so-called hinge vane compressor in which the roller eccentrically rotates with a tip of the vane rotatably fitted in a recess of an outer peripheral surface of the roller.BACKGROUND ART

[0002] Patent Document 1 discloses a compressor provided with a discharge valve that opens and closes a discharge port of a head (an end face member). A base end portion of the discharge valve is fixed to the head with a fastening member.CITATION LISTPATENT DOCUMENT

[0003] Patent Document 1: Japanese Unexamined Patent Publication No. 2009-047018SUMMARY OF THE INVENTIONTECHNICAL PROBLEM

[0004] According to the invention of Patent Document 1, the head is provided with a recess for housing the discharge valve and the fastening member, that is, part of the head where the fastening member is fixed has a reduced thickness. Thus, when the thickness of the head is reduced particularly on the discharge side where the refrigerant pressure is high, the head may be distorted.

[0005] It is an object of the present disclosure to reduce the distortion of the head by fixing the discharge valve at a suitable position.SOLUTION TO THE PROBLEM

[0006] A first aspect of the present disclosure is directed to a rotary compressor including: a shaft (25) extending in a first direction; a first head (31) configured to rotatably support the shaft (25) and having a first discharge port (49) through which a refrigerant is discharged; a cylinder (70) having a cylinder chamber (71) and disposed adjacent to the first head (31); a roller (76) fixed to the shaft (25) and configured to eccentrically rotate in the cylinder chamber (71); a vane (77) configured to partition the cylinder chamber (71) into a suction space and a discharge space; a second head (33) configured to rotatably support the shaft (25) and disposed on an opposite side of the cylinder (70) from the first head (31); a first discharge valve (60) configured to open and close the first discharge port (49); and a first fastener (61) configured to fix a base end portion of the first discharge valve (60) to the first head (31), the cylinder (70) having a vane chamber (73) configured to house the vane (77), the vane chamber (73) having a first center line (L1), the first head (31) being divided into a first region on a side of the first center line (L1) corresponding to the suction space and a second region on a side of the first center line (L1) corresponding to the discharge space when viewed from the first direction, the first fastener (61) being disposed in the first region of the first head (31).

[0007] According to the first aspect, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0008] A second aspect of the present disclosure is an embodiment of the rotary compressor of the first aspect. In the second aspect, the rotary compressor further includes: a fastening bolt (35) configured to fasten the first head (31), the cylinder (70), and the second head (33), wherein a first angle θ1 formed between the first center line (L1) and a straight line connecting a center of the first fastener (61) and a center (O) of the shaft (25) is larger than a second angle θ2 formed between the first center line (L1) and a straight line connecting a center of the fastening bolt (35) and the center (O) of the shaft (25).

[0009] According to the second aspect, the first fastener (61) is located at a position farther from the vane chamber (73) in the circumferential direction than the fastening bolt (35), allowing the first fastener (61) to be fixed at a position further away from the second region where the refrigerant pressure is high.

[0010] A third aspect of the present disclosure is an embodiment of the rotary compressor of the first or second aspect. In the third aspect, the first fastener (61) is located at a position that does not overlap with a suction passage (72) of the cylinder (70) when viewed in the first direction.

[0011] According to the third aspect, the first fastener (61) can be disposed so as not to penetrate the suction passage (72) of the cylinder (70).

[0012] A fourth aspect of the present disclosure is an embodiment of the rotary compressor of any one of the first to third aspects. In the fourth aspect, the cylinder (70) includes a first cylinder (40) having a first cylinder chamber (41) and a second cylinder (50) having a second cylinder chamber (51), the vane (77) includes a first vane (47) and a second vane (57), the first cylinder (40) includes a first vane chamber (43) configured to house the first vane (47) and having the first center line (L1), the second cylinder (50) includes a second vane chamber (53) configured to house the second vane (57) and having a second center line (L2), the second head (33) has a second discharge port (59) through which the refrigerant is discharged, and the rotary compressor further includes: a middle plate (32) disposed between the first cylinder (40) and the second cylinder (50); a second discharge valve (65) configured to open and close the second discharge port (59); and a second fastener (66) configured to fix a base end portion of the second discharge valve (65) to the second head (33).

[0013] According to the fourth aspect, the first fastener (61) and the second fastener (66) can be fixed at suitable positions in a multi-cylinder rotary compressor including the first cylinder (40) and the second cylinder (50).

[0014] A fifth aspect of the present disclosure is an embodiment of the rotary compressor of the fourth aspect. In the fifth aspect, the second head (33) is divided into a third region on a side of the second center line (L2) corresponding to the suction space and a fourth region on a side of the second center line (L2) corresponding to the discharge space when viewed from the first direction, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the fourth region of the second head (33).

[0015] According to the fifth aspect, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0016] A sixth aspect of the present disclosure is an embodiment of the rotary compressor of the fourth aspect. In the sixth aspect, the second head (33) is divided into a third region on a side of the second center line (L2) corresponding to the suction space and a fourth region on a side of the second center line (L2) corresponding to the discharge space when viewed from the first direction, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the third region of the second head (33).

[0017] According to the sixth aspect, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the third region of the second head (33). This can keep the first head (31) and the second head (33) sufficiently thick in the second region and the fourth region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31) and the second head (33).

[0018] A seventh aspect of the present disclosure is an embodiment of the rotary compressor of the sixth aspect. In the seventh aspect, a third angle θ3 formed between a straight line connecting a center (O) of the shaft (25) and a center of a tip end portion of the first discharge valve (60) and a straight line connecting the center (O) of the shaft (25) and a center of the first fastener (61) is different from a fourth angle θ4 formed between a straight line connecting the center (O) of the shaft (25) and a center of a tip end portion of the second discharge valve (65) and a straight line connecting the center (O) of the shaft (25) and a center of the second fastener (66).

[0019] According to the seventh aspect, the third angle θ3 and the fourth angle θ4 differ from each other, allowing more flexible arrangement of the first discharge valve (60) and the second discharge valve (65).

[0020] An eighth aspect of the present disclosure is an embodiment of the rotary compressor of any one of the first to seventh aspects. In the eighth aspect, the first head (31) or the second head (33) includes a radial passage (81) extending in a radial direction and an axial passage (82) communicating with the radial passage (81) and extending in an axial direction, and a suction passage (72) of the cylinder (70) communicates with the axial passage (82).

[0021] According to the eighth aspect, the radial passage (81) and the axial passage (82) are provided in the first head (31) or the second head (33); therefore, the suction passage (72) is not required to penetrate the cylinder (70) outward in the radial direction. This can keep part of the cylinder (70) on the suction passage (72) side sufficiently thick.

[0022] A ninth aspect of the present disclosure is an embodiment of the rotary compressor of any one of the first to eighth aspects. In the ninth aspect, the refrigerant is carbon dioxide.

[0023] According to the ninth aspect, the distortion of the first head (31) can be reduced even when carbon dioxide with a large pressure fluctuation is used as the refrigerant.

[0024] A tenth aspect of the present disclosure is directed to a refrigeration apparatus including the rotary compressor (10) of any one of the first to ninth aspects.

[0025] In the tenth aspect, a refrigeration apparatus including the rotary compressor (10) can be provided.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] [FIG. 1] FIG. 1 is a refrigerant circuit diagram illustrating a configuration of a refrigeration apparatus according to a first embodiment. [FIG. 2] FIG. 2 is a longitudinal sectional view illustrating a configuration of a rotary compressor. [FIG. 3] FIG. 3 is a plan sectional view illustrating a configuration of a first cylinder and a first roller. [FIG. 4] FIG. 4 is a plan sectional view illustrating a configuration of a second cylinder and a second roller. [FIG. 5] FIG. 5 is a plan view illustrating a configuration of a front head. [FIG. 6] FIG. 6 is a view of a rear head from below. [FIG. 7] FIG. 7 is a view of a rear head of a second embodiment from below. DESCRIPTION OF EMBODIMENTS

[0027] As illustrated in FIG. 1, a rotary compressor (10) is provided in a refrigeration apparatus (1). The refrigeration apparatus (1) includes a refrigerant circuit (1a) which is a fluid circuit filled with a refrigerant. In the present embodiment, carbon dioxide is used as the refrigerant.

[0028] The refrigerant circuit (1a) includes the rotary compressor (10), a radiator (3), a decompression mechanism (4), and an evaporator (5). The decompression mechanism (4) is, for example, an expansion valve. The refrigerant circuit (1a) performs a vapor compression refrigeration cycle.

[0029] The refrigeration apparatus (1) is an air conditioner. The air conditioner may be any of a cooling-only apparatus, a heating-only apparatus, or an air conditioner switchable between cooling and heating. In this case, the air conditioner has a switching mechanism (e.g., a four-way switching valve) configured to switch the direction of circulation of the refrigerant. The refrigeration apparatus (1) may be a water heater, a chiller unit, or a cooling apparatus configured to cool air in an internal space. The cooling apparatus cools the air in a refrigerator, a freezer, or a container, for example.

[0030] As illustrated in FIG. 2, the rotary compressor (10) includes a casing (11), a drive mechanism (20), and a compression mechanism (30). The drive mechanism (20) and the compression mechanism (30) are housed in the casing (11).

[0031] The casing (11) is configured as a vertically oriented, cylindrical closed container. A suction pipe (16) passes through, and is fixed to, a barrel of the casing (11). A discharge pipe (17) passes through, and is fixed to, an upper portion of the casing (11).

[0032] An accumulator (85) is connected to the suction pipe (16). The accumulator (85) temporarily stores the refrigerant to be sucked into the rotary compressor (10) and performs gas-liquid separation for the liquid refrigerant and oil contained in the gas refrigerant.

[0033] The casing (11) has an oil reservoir (18) at its bottom. The oil reservoir (18) stores oil for lubricating sliding portions of the compression mechanism (30) and a shaft (25).<Drive Mechanism>

[0034] The drive mechanism (20) includes a motor (21) and a shaft (25). The motor (21) is disposed above the compression mechanism (30). The motor (21) includes a stator (22) and a rotor (23).

[0035] The stator (22) is fixed to the inner peripheral surface of the casing (11). The rotor (23) extends in the up-and-down direction through the interior of the stator (22). The shaft (25) passes through the axis of the rotor (23) and is fixed to the rotor (23). The shaft (25) is driven to rotate together with the rotor (23) when the motor (21) is energized.

[0036] The shaft (25) is disposed on the axis of the casing (11). The shaft (25) extends in a first direction (the up-and-down direction in FIG. 2). An oil supply pump (25a) is provided at a lower end of the shaft (25). The oil supply pump (25a) conveys the oil collected in the oil reservoir (18). The conveyed oil is supplied to the sliding portions of the compression mechanism (30) and the shaft (25) through an oil passage (25b) in the shaft (25).

[0037] The shaft (25) includes a main shaft portion (26), a first eccentric portion (27), and a second eccentric portion (28). An upper portion of the main shaft portion (26) is fixed to the rotor (23) of the motor (21). The first eccentric portion (27) is disposed above the second eccentric portion (28). The axes of the first eccentric portion (27) and the second eccentric portion (28) are eccentric from the axis of the main shaft portion (26) by a predetermined amount.

[0038] Part of the main shaft portion (26) above the first eccentric portion (27) is rotatably supported by a front head (31) described later. Part of the main shaft portion (26) below the second eccentric portion (28) is rotatably supported by a rear head (33) described later.<Compression Mechanism>

[0039] In the example shown in FIG. 2, the compression mechanism (30) is a two-cylinder rotary fluid machine. The compression mechanism (30) is disposed below the motor (21).

[0040] The compression mechanism (30) includes a cylinder (70) having a cylinder chamber (71). The cylinder chamber (71) houses a roller (76). The cylinder (70) has a suction passage (72) through which the refrigerant is sucked and a vane chamber (73) that houses a vane (77).

[0041] The cylinder chamber (71) includes a first cylinder chamber (41) and a second cylinder chamber (51). The cylinder (70) includes a first cylinder (40) having the first cylinder chamber (41) and a second cylinder (50) having the second cylinder chamber (51). The suction passage (72) includes a first suction passage (42) through which the refrigerant is sucked into the first cylinder chamber (41), and a second suction passage (52) through which the refrigerant is sucked into the second cylinder chamber (51).

[0042] The roller (76) includes a first roller (46) housed in the first cylinder chamber (41) and a second roller (56) housed in the second cylinder chamber (51).

[0043] As illustrated in FIGS. 3 and 4, the vane chamber (73) includes a first vane chamber (43) provided in the first cylinder (40) and a second vane chamber (53) provided in the second cylinder (50). The vane (77) includes a first vane (47) housed in the first vane chamber (43) and a second vane (57) housed in the second vane chamber (53).

[0044] As illustrated in FIG. 2, the compression mechanism (30) includes a front head (31) as a first head, the first cylinder (40), a middle plate (32), the second cylinder (50), and the rear head (33) as a second head.

[0045] The front head (31), the first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33) are stacked in this order from top to bottom and fixed with a fastening bolt (35).

[0046] Specifically, the front head (31) is provided with a threaded hole (36). The first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33) are each provided with a through hole (37) located to correspond to the threaded hole (36).

[0047] The fastening bolt (35) is inserted into the holes from the rear head (33) side and fastens the front head (31), the first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33).

[0048] The front head (31) is fixed to the casing (11). The front head (31) is stacked on top of the first cylinder (40). The front head (31) is arranged to cover the first cylinder chamber (41) of the first cylinder (40) from above. The main shaft portion (26) of the shaft (25) is inserted in the front head (31) to pass through the center of the front head (31). The front head (31) rotatably supports the shaft (25). The front head (31) has a first discharge port (49) penetrating the front head (31) in the axial direction (see FIG. 3).

[0049] The first cylinder (40) is configured as a flat, substantially annular member. The first cylinder (40) is disposed adjacent to the front head (31). As illustrated in FIG. 3, the first cylinder (40) includes the first cylinder chamber (41), the first suction passage (42), the first vane chamber (43), and a first communication passage (44).

[0050] The first cylinder chamber (41) is provided in the center of the first cylinder (40). The first suction passage (42) extends in the axial direction from the lower surface of the first cylinder (40). The first suction passage (42) communicates with a head-side suction passage (80) described later. The first communication passage (44) communicates with the first suction passage (42) and the first cylinder chamber (41).

[0051] The first cylinder chamber (41) houses the first roller (46). The first roller (46) is formed in an annular shape. The first roller (46) is fixed to the first eccentric portion (27) of the shaft (25). Specifically, the first eccentric portion (27) of the shaft (25) is fitted into the first roller (46).

[0052] The first vane (47) extends radially outward from the first roller (46). The first vane (47) is supported by a pair of first bushes (48). The first vane (47) partitions the inside of the first cylinder chamber (41) into a suction space and a discharge space.

[0053] The first roller (46) rotates eccentrically in the first cylinder chamber (41) when the shaft (25) is driven to rotate. When the volume of the suction space gradually increases with the eccentric rotation of the first roller (46), the refrigerant flowing through the suction pipe (16) is sucked through the first suction passage (42) into the suction space in the radial direction.

[0054] When the suction space is isolated from the first suction passage (42), the isolated space constitutes the discharge space. The internal pressure of the discharge space increases as the volume of the discharge space gradually decreases. When the internal pressure of the discharge space exceeds a predetermined pressure, the refrigerant in the discharge space flows out of the compression mechanism (30) through the first discharge port (49). The high-pressure refrigerant flows upward through the internal space of the casing (11) and passes through a core cut (not shown) of the motor (21) or any other passage. The high-pressure refrigerant that has flowed upward of the motor (21) is transferred to the refrigerant circuit through the discharge pipe (17).

[0055] The first vane chamber (43) is located radially outward of the first cylinder chamber (41) and away from the first cylinder chamber (41). The first vane chamber (43) penetrates the first cylinder (40) in the thickness direction. The first vane chamber (43) houses a tip end portion of the first vane (47). The first vane (47) oscillates in the first vane chamber (43) with the eccentric rotation of the first roller (46).

[0056] As illustrated in FIG. 2, the middle plate (32) is sandwiched between the first cylinder (40) and the second cylinder (50). The middle plate (32) is disposed to cover the first cylinder chamber (41) of the first cylinder (40) from below. The middle plate (32) is disposed to cover the second cylinder chamber (51) of the second cylinder (50) from above.

[0057] A through hole (32a) is formed in the middle plate (32). The through hole (32a) communicates with the first suction passage (42) of the first cylinder (40) and the second suction passage (52), which will be described later, of the second cylinder (50).

[0058] As also illustrated in FIG. 4, the second cylinder (50) is configured as a flat, substantially annular member. The second cylinder (50) includes the second cylinder chamber (51), the second suction passage (52), the second vane chamber (53), and a second communication passage (54).

[0059] The second cylinder chamber (51) is provided in the center of the second cylinder (50). The second suction passage (52) extends to penetrate the second cylinder (50) in the axial direction. The second suction passage (52) communicates with a head-side suction passage (80) described later. The second communication passage (54) communicates with the second suction passage (52) and the second cylinder chamber (51).

[0060] The second cylinder chamber (51) houses the second roller (56). The second roller (56) is formed in an annular shape. The second roller (56) is fixed to the second eccentric portion (28) of the shaft (25). Specifically, the second eccentric portion (28) of the shaft (25) is fitted into the second roller (56).

[0061] The second vane (57) extends radially outward from the second roller (56). The second vane (57) is supported by a pair of second bushes (58). The second vane (57) partitions the inside of the second cylinder chamber (51) into a suction space and a discharge space.

[0062] The operation of the second roller (56) is substantially the same as the operation of the first roller (46), and will not be described below.

[0063] The second vane chamber (53) is located radially outward of the second cylinder chamber (51) and away from the second cylinder chamber (51). The second vane chamber (53) penetrates the second cylinder (50) in the thickness direction. The second vane chamber (53) houses a tip end portion of the second vane (57). The second vane (57) oscillates in the second vane chamber (53) with the eccentric rotation of the second roller (56).

[0064] As illustrated in FIG. 2, the rear head (33) is stacked on the bottom of the second cylinder (50). The rear head (33) is disposed to cover the second cylinder chamber (51) of the second cylinder (50) from below. The main shaft portion (26) of the shaft (25) is inserted in the rear head (33) to pass through the center of the rear head (33). The rear head (33) rotatably supports the shaft (25).

[0065] The rear head (33) is provided with the head-side suction passage (80). The head-side suction passage (80) includes a radial passage (81) and an axial passage (82). The radial passage (81) extends outward in the radial direction of the rear head (33). The radial passage (81) opens to the outer surface of the rear head (33). The suction pipe (16) is connected to an inlet end of the radial passage (81). The axial passage (82) is provided at an outlet end of the radial passage (81).

[0066] The axial passage (82) extends upward in the axial direction and opens to the upper surface of the rear head (33). An outlet end of the axial passage (82) communicates with the second suction passage (52) of the second cylinder (50).

[0067] The refrigerant sucked into the head-side suction passage (80) of the rear head (33) flows through the second suction passage (52) of the second cylinder (50), the through hole (32a) of the middle plate (32), and the first suction passage (42) of the first cylinder (40).

[0068] The refrigerant is sucked into the first cylinder chamber (41) through the first suction passage (42) and the first communication passage (44). The refrigerant is sucked into the second cylinder chamber (51) through the second suction passage (52) and the second communication passage (54).

[0069] The rear head (33) has a second discharge port (59) penetrating the rear head (33) in the axial direction (see FIG. 4). When the internal pressure of the discharge space in the second cylinder chamber (51) exceeds a predetermined pressure with the rotation of the second roller (56), the refrigerant in the discharge space flows out of the compression mechanism (30) through the second discharge port (59).<First Discharge Valve>

[0070] As illustrated in FIG. 5, a first discharge valve (60) is attached to the front head (31). A tip end portion of the first discharge valve (60) opens and closes the first discharge port (49). A base end portion of the first discharge valve (60) is fixed to the front head (31) with a first fastener (61). The first fastener (61) is, for example, a rivet. The first fastener (61) may be a fastening bolt.

[0071] The front head (31) has a first recess (62). The first discharge valve (60) and the first fastener (61) are housed in the first recess (62).<Second Discharge Valve>

[0072] As illustrated in FIG. 6, a second discharge valve (65) is attached to the rear head (33). A tip end portion of the second discharge valve (65) opens and closes the second discharge port (59). A base end portion of the second discharge valve (65) is fixed to the rear head (33) with a second fastener (66). The second fastener (66) is, for example, a rivet. The second fastener (66) may be a fastening bolt.

[0073] The rear head (33) has a second recess (67). The second discharge valve (65) and the second fastener (66) are housed in the second recess (67).<Fixing Position of First Fastener>

[0074] The front head (31) has the first recess (62) that houses the first discharge valve (60) and the first fastener (61), that is, a portion of the front head (31) where the first fastener (61) is fixed has a reduced thickness. Thus, when the thickness of the front head (31) is reduced particularly on the discharge side where the refrigerant pressure is high, the front head (31) may be distorted.

[0075] To address this, in the present embodiment, the first discharge valve (60) is fixed to a suitable position to reduce the distortion of the front head.

[0076] Specifically, as illustrated in FIG. 3, the first vane chamber (43) has a first center line (L1). The first center line (L1) is a straight line connecting the center (O) of the shaft (25) and the top dead center of the first roller (46) (the position in FIG. 3).

[0077] As illustrated in FIG. 5, the front head (31) is divided into a first region on the side of the first center line (L1) corresponding to the suction space and a second region on the side of the first center line (L1) corresponding to the discharge space when viewed in the axial direction, which is the first direction. The first fastener (61) is disposed in the first region of the front head (31). The first fastener (61) is located at a position that does not overlap with the first suction passage (42) of the first cylinder (40) when viewed in the axial direction.

[0078] As illustrated in FIG. 2, the front head (31), the first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33) are fastened together with the fastening bolt (35). The fastening bolt (35) is tightened to a threaded hole (36) of the front head (31).

[0079] Here, as illustrated in FIG. 5, an angle formed between the first center line (L1) and a straight line connecting the center of the first fastener (61) and the center (O) of the shaft (25) is referred to as a first angle θ1. An angle formed between the first center line (L1) and a straight line connecting the center of the fastening bolt (35) (illustrated as the center of the threaded hole (36) in FIG. 5) and the center (O) of the shaft (25) is referred to as a second angle θ2. The first angle θ1 is set larger than the second angle θ2.

[0080] As illustrated in FIG. 4, the second vane chamber (53) has a second center line (L2). The second center line (L2) is a straight line connecting the center (O) of the shaft (25) and the top dead center of the second roller (56).

[0081] As illustrated in FIG. 6, the rear head (33) is divided into a third region on the side of the second center line (L2) corresponding to the suction space and a fourth region on the side of the second center line (L2) corresponding to the discharge space when viewed in the axial direction, which is the first direction. The second fastener (66) is disposed in the third region of the rear head (33).

[0082] As illustrated in FIG. 5, an angle formed between a straight line connecting the center (O) of the shaft (25) and the center of the tip end portion of the first discharge valve (60) and a straight line connecting the center (O) of the shaft (25) and the center of the first fastener (61) is referred to as a third angle θ3. As illustrated in FIG. 6, an angle formed between a straight line connecting the center (O) of the shaft (25) and the center of the tip end portion of the second discharge valve (65) and a straight line connecting the center (O) of the shaft (25) and the center of the second fastener (66) is referred to as a fourth angle θ4. The third angle θ3 is set to be different from the fourth angle θ4. The third angle θ3 and the fourth angle θ4 may be the same angle.-Advantages of First Embodiment-

[0083] According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0084] According to the present embodiment, the first fastener (61) is located at a position farther from the vane chamber (73) in the circumferential direction than the fastening bolt (35), allowing the first fastener (61) to be fixed at a position further away from the second region where the refrigerant pressure is high.

[0085] According to the present embodiment, the first fastener (61) can be disposed so as not to penetrate the suction passage (72) of the cylinder (70).

[0086] According to the present embodiment, the first fastener (61) and the second fastener (66) can be fixed at suitable positions in a multi-cylinder rotary compressor including the first cylinder (40) and the second cylinder (50).

[0087] According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the third region of the second head (33). This can keep the first head (31) and the second head (33) sufficiently thick in the second region and the fourth region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31) and the second head (33).

[0088] According to the present embodiment, the third angle θ3 and the fourth angle θ4 differ from each other, allowing more flexible arrangement of the first discharge valve (60) and the second discharge valve (65).

[0089] According to the present embodiment, the radial passage (81) and the axial passage (82) are provided in the first head (31) or the second head (33); therefore, the suction passage (72) is not required to penetrate the cylinder (70) outward in the radial direction. This can keep part of the cylinder (70) on the suction passage (72) side sufficiently thick.

[0090] According to the present embodiment, the distortion of the first head (31) can be reduced even when carbon dioxide with a large pressure fluctuation is used as the refrigerant.

[0091] According to the present embodiment, a refrigeration apparatus including the rotary compressor (10) can be provided.«Second Embodiment»

[0092] In the following description, the same reference characters designate the same components as those of the first embodiment, and the description is focused only on the differences.

[0093] As illustrated in FIG. 7, the second vane chamber (53) has a second center line (L2). The second center line (L2) is a straight line connecting the center (O) of the shaft (25) and the top dead center of the second roller (56).

[0094] The rear head (33) is divided into a third region on the side of the second center line (L2) corresponding to the suction space and a fourth region on the side of the second center line (L2) corresponding to the discharge space when viewed in the axial direction, which is the first direction. The second fastener (66) is disposed in the fourth region of the rear head (33).

[0095] The front head (31) is configured in the same manner as that of the first embodiment, and will not be described below.-Advantages of Second Embodiment-

[0096] According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0097] The second fastener (66) is disposed in the fourth region on the side of the second center line (L2) corresponding to the discharge space in consideration of design flexibility.«Other Embodiments»

[0098] While the embodiments and variations have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims. The elements according to embodiments, the variations thereof, and the other embodiments may be combined and replaced with each other. In addition, the expressions of "first," "second," "third," . . . , in the specification and claims are used to distinguish the terms to which these expressions are given, and do not limit the number and order of the terms.INDUSTRIAL APPLICABILITY

[0099] As described above, the present disclosure is useful for a rotary compressor and a refrigeration apparatus.DESCRIPTION OF REFERENCE CHARACTERS

[0100] 1Refrigeration Apparatus 10Rotary Compressor 25Shaft 31Front Head (First Head) 32Middle Plate 33Rear Head (Second Head) 35Fastening Bolt 40First Cylinder 41First Cylinder Chamber 43First Vane Chamber 47First Vane 49First Discharge Port 50Second Cylinder 51Second Cylinder Chamber 53Second Vane Chamber 57Second Vane 59Second Discharge Port 60First Discharge Valve 61First Fastener 65Second Discharge Valve 66Second Fastener 70Cylinder 71Cylinder Chamber 72Suction Passage 73Vane Chamber 76Roller 77Vane 81Radial Passage 82Axial Passage L1First Center Line L2Second Center Line θ1First Angle θ2Second Angle θ3Third Angle θ4Fourth Angle

Examples

first embodiment

-Advantages of First Embodiment-

[0083]According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0084]According to the present embodiment, the first fastener (61) is located at a position farther from the vane chamber (73) in the circumferential direction than the fastening bolt (35), allowing the first fastener (61) to be fixed at a position further away from the second region where the refrigerant pressure is high.

[0085] According to the present embodiment, the first fastener (61) can be disposed so as not to penetrate the suction passage (72) of the cylinder (70).

[0086]According to the present embodiment, the first fastener (61) and the second fastener (66) can be fixed at suitable positions in a multi-cylinder rotary compressor including the first cyl...

« second embodiment »

«Second Embodiment»

[0092]In the following description, the same reference characters designate the same components as those of the first embodiment, and the description is focused only on the differences.

[0093]As illustrated in FIG. 7, the second vane chamber (53) has a second center line (L2). The second center line (L2) is a straight line connecting the center (O) of the shaft (25) and the top dead center of the second roller (56).

[0094]The rear head (33) is divided into a third region on the side of the second center line (L2) corresponding to the suction space and a fourth region on the side of the second center line (L2) corresponding to the discharge space when viewed in the axial direction, which is the first direction. The second fastener (66) is disposed in the fourth region of the rear head (33).

[0095]The front head (31) is configured in the same manner as that of the first embodiment, and will not be described below.

second embodiment

-Advantages of Second Embodiment-

[0096]According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0097]The second fastener (66) is disposed in the fourth region on the side of the second center line (L2) corresponding to the discharge space in consideration of design flexibility.

TECHNICAL FIELD

[0001] The present disclosure relates to a rotary compressor and a refrigeration apparatus. 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 a compression chamber. There are various types of rotary compressors, such as a so-called rolling piston compressor in which a roller eccentrically rotates while a vane separate from the roller abuts on the roller, a so-called swing compressor in which a vane integrally formed with the roller oscillates with the eccentric rotation of the roller, and a so-called hinge vane compressor in which the roller eccentrically rotates with a tip of the vane rotatably fitted in a recess of an outer peripheral surface of the roller.BACKGROUND ART

[0002] Patent Document 1 discloses a compressor provided with a discharge valve that opens and closes a discharge port of a head (an end face member). A base end portion of the discharge valve is fixed to the head with a fastening member.CITATION LISTPATENT DOCUMENT

[0003] Patent Document 1: Japanese Unexamined Patent Publication No. 2009-047018SUMMARY OF THE INVENTIONTECHNICAL PROBLEM

[0004] According to the invention of Patent Document 1, the head is provided with a recess for housing the discharge valve and the fastening member, that is, part of the head where the fastening member is fixed has a reduced thickness. Thus, when the thickness of the head is reduced particularly on the discharge side where the refrigerant pressure is high, the head may be distorted.

[0005] It is an object of the present disclosure to reduce the distortion of the head by fixing the discharge valve at a suitable position.SOLUTION TO THE PROBLEM

[0006] A first aspect of the present disclosure is directed to a rotary compressor including: a shaft (25) extending in a first direction; a first head (31) configured to rotatably support the shaft (25) and having a first discharge port (49) through which a refrigerant is discharged; a cylinder (70) having a cylinder chamber (71) and disposed adjacent to the first head (31); a roller (76) fixed to the shaft (25) and configured to eccentrically rotate in the cylinder chamber (71); a vane (77) configured to partition the cylinder chamber (71) into a suction space and a discharge space; a second head (33) configured to rotatably support the shaft (25) and disposed on an opposite side of the cylinder (70) from the first head (31); a first discharge valve (60) configured to open and close the first discharge port (49); and a first fastener (61) configured to fix a base end portion of the first discharge valve (60) to the first head (31), the cylinder (70) having a vane chamber (73) configured to house the vane (77), the vane chamber (73) having a first center line (L1), the first head (31) being divided into a first region on a side of the first center line (L1) corresponding to the suction space and a second region on a side of the first center line (L1) corresponding to the discharge space when viewed from the first direction, the first fastener (61) being disposed in the first region of the first head (31).

[0007] According to the first aspect, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0008] A second aspect of the present disclosure is an embodiment of the rotary compressor of the first aspect. In the second aspect, the rotary compressor further includes: a fastening bolt (35) configured to fasten the first head (31), the cylinder (70), and the second head (33), wherein a first angle θ1 formed between the first center line (L1) and a straight line connecting a center of the first fastener (61) and a center (O) of the shaft (25) is larger than a second angle θ2 formed between the first center line (L1) and a straight line connecting a center of the fastening bolt (35) and the center (O) of the shaft (25).

[0009] According to the second aspect, the first fastener (61) is located at a position farther from the vane chamber (73) in the circumferential direction than the fastening bolt (35), allowing the first fastener (61) to be fixed at a position further away from the second region where the refrigerant pressure is high.

[0010] A third aspect of the present disclosure is an embodiment of the rotary compressor of the first or second aspect. In the third aspect, the first fastener (61) is located at a position that does not overlap with a suction passage (72) of the cylinder (70) when viewed in the first direction.

[0011] According to the third aspect, the first fastener (61) can be disposed so as not to penetrate the suction passage (72) of the cylinder (70).

[0012] A fourth aspect of the present disclosure is an embodiment of the rotary compressor of any one of the first to third aspects. In the fourth aspect, the cylinder (70) includes a first cylinder (40) having a first cylinder chamber (41) and a second cylinder (50) having a second cylinder chamber (51), the vane (77) includes a first vane (47) and a second vane (57), the first cylinder (40) includes a first vane chamber (43) configured to house the first vane (47) and having the first center line (L1), the second cylinder (50) includes a second vane chamber (53) configured to house the second vane (57) and having a second center line (L2), the second head (33) has a second discharge port (59) through which the refrigerant is discharged, and the rotary compressor further includes: a middle plate (32) disposed between the first cylinder (40) and the second cylinder (50); a second discharge valve (65) configured to open and close the second discharge port (59); and a second fastener (66) configured to fix a base end portion of the second discharge valve (65) to the second head (33).

[0013] According to the fourth aspect, the first fastener (61) and the second fastener (66) can be fixed at suitable positions in a multi-cylinder rotary compressor including the first cylinder (40) and the second cylinder (50).

[0014] A fifth aspect of the present disclosure is an embodiment of the rotary compressor of the fourth aspect. In the fifth aspect, the second head (33) is divided into a third region on a side of the second center line (L2) corresponding to the suction space and a fourth region on a side of the second center line (L2) corresponding to the discharge space when viewed from the first direction, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the fourth region of the second head (33).

[0015] According to the fifth aspect, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0016] A sixth aspect of the present disclosure is an embodiment of the rotary compressor of the fourth aspect. In the sixth aspect, the second head (33) is divided into a third region on a side of the second center line (L2) corresponding to the suction space and a fourth region on a side of the second center line (L2) corresponding to the discharge space when viewed from the first direction, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the third region of the second head (33).

[0017] According to the sixth aspect, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the third region of the second head (33). This can keep the first head (31) and the second head (33) sufficiently thick in the second region and the fourth region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31) and the second head (33).

[0018] A seventh aspect of the present disclosure is an embodiment of the rotary compressor of the sixth aspect. In the seventh aspect, a third angle θ3 formed between a straight line connecting a center (O) of the shaft (25) and a center of a tip end portion of the first discharge valve (60) and a straight line connecting the center (O) of the shaft (25) and a center of the first fastener (61) is different from a fourth angle θ4 formed between a straight line connecting the center (O) of the shaft (25) and a center of a tip end portion of the second discharge valve (65) and a straight line connecting the center (O) of the shaft (25) and a center of the second fastener (66).

[0019] According to the seventh aspect, the third angle θ3 and the fourth angle θ4 differ from each other, allowing more flexible arrangement of the first discharge valve (60) and the second discharge valve (65).

[0020] An eighth aspect of the present disclosure is an embodiment of the rotary compressor of any one of the first to seventh aspects. In the eighth aspect, the first head (31) or the second head (33) includes a radial passage (81) extending in a radial direction and an axial passage (82) communicating with the radial passage (81) and extending in an axial direction, and a suction passage (72) of the cylinder (70) communicates with the axial passage (82).

[0021] According to the eighth aspect, the radial passage (81) and the axial passage (82) are provided in the first head (31) or the second head (33); therefore, the suction passage (72) is not required to penetrate the cylinder (70) outward in the radial direction. This can keep part of the cylinder (70) on the suction passage (72) side sufficiently thick.

[0022] A ninth aspect of the present disclosure is an embodiment of the rotary compressor of any one of the first to eighth aspects. In the ninth aspect, the refrigerant is carbon dioxide.

[0023] According to the ninth aspect, the distortion of the first head (31) can be reduced even when carbon dioxide with a large pressure fluctuation is used as the refrigerant.

[0024] A tenth aspect of the present disclosure is directed to a refrigeration apparatus including the rotary compressor (10) of any one of the first to ninth aspects.

[0025] In the tenth aspect, a refrigeration apparatus including the rotary compressor (10) can be provided.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] [FIG. 1] FIG. 1 is a refrigerant circuit diagram illustrating a configuration of a refrigeration apparatus according to a first embodiment. [FIG. 2] FIG. 2 is a longitudinal sectional view illustrating a configuration of a rotary compressor. [FIG. 3] FIG. 3 is a plan sectional view illustrating a configuration of a first cylinder and a first roller. [FIG. 4] FIG. 4 is a plan sectional view illustrating a configuration of a second cylinder and a second roller. [FIG. 5] FIG. 5 is a plan view illustrating a configuration of a front head. [FIG. 6] FIG. 6 is a view of a rear head from below. [FIG. 7] FIG. 7 is a view of a rear head of a second embodiment from below. DESCRIPTION OF EMBODIMENTS

[0027] As illustrated in FIG. 1, a rotary compressor (10) is provided in a refrigeration apparatus (1). The refrigeration apparatus (1) includes a refrigerant circuit (1a) which is a fluid circuit filled with a refrigerant. In the present embodiment, carbon dioxide is used as the refrigerant.

[0028] The refrigerant circuit (1a) includes the rotary compressor (10), a radiator (3), a decompression mechanism (4), and an evaporator (5). The decompression mechanism (4) is, for example, an expansion valve. The refrigerant circuit (1a) performs a vapor compression refrigeration cycle.

[0029] The refrigeration apparatus (1) is an air conditioner. The air conditioner may be any of a cooling-only apparatus, a heating-only apparatus, or an air conditioner switchable between cooling and heating. In this case, the air conditioner has a switching mechanism (e.g., a four-way switching valve) configured to switch the direction of circulation of the refrigerant. The refrigeration apparatus (1) may be a water heater, a chiller unit, or a cooling apparatus configured to cool air in an internal space. The cooling apparatus cools the air in a refrigerator, a freezer, or a container, for example.

[0030] As illustrated in FIG. 2, the rotary compressor (10) includes a casing (11), a drive mechanism (20), and a compression mechanism (30). The drive mechanism (20) and the compression mechanism (30) are housed in the casing (11).

[0031] The casing (11) is configured as a vertically oriented, cylindrical closed container. A suction pipe (16) passes through, and is fixed to, a barrel of the casing (11). A discharge pipe (17) passes through, and is fixed to, an upper portion of the casing (11).

[0032] An accumulator (85) is connected to the suction pipe (16). The accumulator (85) temporarily stores the refrigerant to be sucked into the rotary compressor (10) and performs gas-liquid separation for the liquid refrigerant and oil contained in the gas refrigerant.

[0033] The casing (11) has an oil reservoir (18) at its bottom. The oil reservoir (18) stores oil for lubricating sliding portions of the compression mechanism (30) and a shaft (25).<Drive Mechanism>

[0034] The drive mechanism (20) includes a motor (21) and a shaft (25). The motor (21) is disposed above the compression mechanism (30). The motor (21) includes a stator (22) and a rotor (23).

[0035] The stator (22) is fixed to the inner peripheral surface of the casing (11). The rotor (23) extends in the up-and-down direction through the interior of the stator (22). The shaft (25) passes through the axis of the rotor (23) and is fixed to the rotor (23). The shaft (25) is driven to rotate together with the rotor (23) when the motor (21) is energized.

[0036] The shaft (25) is disposed on the axis of the casing (11). The shaft (25) extends in a first direction (the up-and-down direction in FIG. 2). An oil supply pump (25a) is provided at a lower end of the shaft (25). The oil supply pump (25a) conveys the oil collected in the oil reservoir (18). The conveyed oil is supplied to the sliding portions of the compression mechanism (30) and the shaft (25) through an oil passage (25b) in the shaft (25).

[0037] The shaft (25) includes a main shaft portion (26), a first eccentric portion (27), and a second eccentric portion (28). An upper portion of the main shaft portion (26) is fixed to the rotor (23) of the motor (21). The first eccentric portion (27) is disposed above the second eccentric portion (28). The axes of the first eccentric portion (27) and the second eccentric portion (28) are eccentric from the axis of the main shaft portion (26) by a predetermined amount.

[0038] Part of the main shaft portion (26) above the first eccentric portion (27) is rotatably supported by a front head (31) described later. Part of the main shaft portion (26) below the second eccentric portion (28) is rotatably supported by a rear head (33) described later.<Compression Mechanism>

[0039] In the example shown in FIG. 2, the compression mechanism (30) is a two-cylinder rotary fluid machine. The compression mechanism (30) is disposed below the motor (21).

[0040] The compression mechanism (30) includes a cylinder (70) having a cylinder chamber (71). The cylinder chamber (71) houses a roller (76). The cylinder (70) has a suction passage (72) through which the refrigerant is sucked and a vane chamber (73) that houses a vane (77).

[0041] The cylinder chamber (71) includes a first cylinder chamber (41) and a second cylinder chamber (51). The cylinder (70) includes a first cylinder (40) having the first cylinder chamber (41) and a second cylinder (50) having the second cylinder chamber (51). The suction passage (72) includes a first suction passage (42) through which the refrigerant is sucked into the first cylinder chamber (41), and a second suction passage (52) through which the refrigerant is sucked into the second cylinder chamber (51).

[0042] The roller (76) includes a first roller (46) housed in the first cylinder chamber (41) and a second roller (56) housed in the second cylinder chamber (51).

[0043] As illustrated in FIGS. 3 and 4, the vane chamber (73) includes a first vane chamber (43) provided in the first cylinder (40) and a second vane chamber (53) provided in the second cylinder (50). The vane (77) includes a first vane (47) housed in the first vane chamber (43) and a second vane (57) housed in the second vane chamber (53).

[0044] As illustrated in FIG. 2, the compression mechanism (30) includes a front head (31) as a first head, the first cylinder (40), a middle plate (32), the second cylinder (50), and the rear head (33) as a second head.

[0045] The front head (31), the first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33) are stacked in this order from top to bottom and fixed with a fastening bolt (35).

[0046] Specifically, the front head (31) is provided with a threaded hole (36). The first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33) are each provided with a through hole (37) located to correspond to the threaded hole (36).

[0047] The fastening bolt (35) is inserted into the holes from the rear head (33) side and fastens the front head (31), the first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33).

[0048] The front head (31) is fixed to the casing (11). The front head (31) is stacked on top of the first cylinder (40). The front head (31) is arranged to cover the first cylinder chamber (41) of the first cylinder (40) from above. The main shaft portion (26) of the shaft (25) is inserted in the front head (31) to pass through the center of the front head (31). The front head (31) rotatably supports the shaft (25). The front head (31) has a first discharge port (49) penetrating the front head (31) in the axial direction (see FIG. 3).

[0049] The first cylinder (40) is configured as a flat, substantially annular member. The first cylinder (40) is disposed adjacent to the front head (31). As illustrated in FIG. 3, the first cylinder (40) includes the first cylinder chamber (41), the first suction passage (42), the first vane chamber (43), and a first communication passage (44).

[0050] The first cylinder chamber (41) is provided in the center of the first cylinder (40). The first suction passage (42) extends in the axial direction from the lower surface of the first cylinder (40). The first suction passage (42) communicates with a head-side suction passage (80) described later. The first communication passage (44) communicates with the first suction passage (42) and the first cylinder chamber (41).

[0051] The first cylinder chamber (41) houses the first roller (46). The first roller (46) is formed in an annular shape. The first roller (46) is fixed to the first eccentric portion (27) of the shaft (25). Specifically, the first eccentric portion (27) of the shaft (25) is fitted into the first roller (46).

[0052] The first vane (47) extends radially outward from the first roller (46). The first vane (47) is supported by a pair of first bushes (48). The first vane (47) partitions the inside of the first cylinder chamber (41) into a suction space and a discharge space.

[0053] The first roller (46) rotates eccentrically in the first cylinder chamber (41) when the shaft (25) is driven to rotate. When the volume of the suction space gradually increases with the eccentric rotation of the first roller (46), the refrigerant flowing through the suction pipe (16) is sucked through the first suction passage (42) into the suction space in the radial direction.

[0054] When the suction space is isolated from the first suction passage (42), the isolated space constitutes the discharge space. The internal pressure of the discharge space increases as the volume of the discharge space gradually decreases. When the internal pressure of the discharge space exceeds a predetermined pressure, the refrigerant in the discharge space flows out of the compression mechanism (30) through the first discharge port (49). The high-pressure refrigerant flows upward through the internal space of the casing (11) and passes through a core cut (not shown) of the motor (21) or any other passage. The high-pressure refrigerant that has flowed upward of the motor (21) is transferred to the refrigerant circuit through the discharge pipe (17).

[0055] The first vane chamber (43) is located radially outward of the first cylinder chamber (41) and away from the first cylinder chamber (41). The first vane chamber (43) penetrates the first cylinder (40) in the thickness direction. The first vane chamber (43) houses a tip end portion of the first vane (47). The first vane (47) oscillates in the first vane chamber (43) with the eccentric rotation of the first roller (46).

[0056] As illustrated in FIG. 2, the middle plate (32) is sandwiched between the first cylinder (40) and the second cylinder (50). The middle plate (32) is disposed to cover the first cylinder chamber (41) of the first cylinder (40) from below. The middle plate (32) is disposed to cover the second cylinder chamber (51) of the second cylinder (50) from above.

[0057] A through hole (32a) is formed in the middle plate (32). The through hole (32a) communicates with the first suction passage (42) of the first cylinder (40) and the second suction passage (52), which will be described later, of the second cylinder (50).

[0058] As also illustrated in FIG. 4, the second cylinder (50) is configured as a flat, substantially annular member. The second cylinder (50) includes the second cylinder chamber (51), the second suction passage (52), the second vane chamber (53), and a second communication passage (54).

[0059] The second cylinder chamber (51) is provided in the center of the second cylinder (50). The second suction passage (52) extends to penetrate the second cylinder (50) in the axial direction. The second suction passage (52) communicates with a head-side suction passage (80) described later. The second communication passage (54) communicates with the second suction passage (52) and the second cylinder chamber (51).

[0060] The second cylinder chamber (51) houses the second roller (56). The second roller (56) is formed in an annular shape. The second roller (56) is fixed to the second eccentric portion (28) of the shaft (25). Specifically, the second eccentric portion (28) of the shaft (25) is fitted into the second roller (56).

[0061] The second vane (57) extends radially outward from the second roller (56). The second vane (57) is supported by a pair of second bushes (58). The second vane (57) partitions the inside of the second cylinder chamber (51) into a suction space and a discharge space.

[0062] The operation of the second roller (56) is substantially the same as the operation of the first roller (46), and will not be described below.

[0063] The second vane chamber (53) is located radially outward of the second cylinder chamber (51) and away from the second cylinder chamber (51). The second vane chamber (53) penetrates the second cylinder (50) in the thickness direction. The second vane chamber (53) houses a tip end portion of the second vane (57). The second vane (57) oscillates in the second vane chamber (53) with the eccentric rotation of the second roller (56).

[0064] As illustrated in FIG. 2, the rear head (33) is stacked on the bottom of the second cylinder (50). The rear head (33) is disposed to cover the second cylinder chamber (51) of the second cylinder (50) from below. The main shaft portion (26) of the shaft (25) is inserted in the rear head (33) to pass through the center of the rear head (33). The rear head (33) rotatably supports the shaft (25).

[0065] The rear head (33) is provided with the head-side suction passage (80). The head-side suction passage (80) includes a radial passage (81) and an axial passage (82). The radial passage (81) extends outward in the radial direction of the rear head (33). The radial passage (81) opens to the outer surface of the rear head (33). The suction pipe (16) is connected to an inlet end of the radial passage (81). The axial passage (82) is provided at an outlet end of the radial passage (81).

[0066] The axial passage (82) extends upward in the axial direction and opens to the upper surface of the rear head (33). An outlet end of the axial passage (82) communicates with the second suction passage (52) of the second cylinder (50).

[0067] The refrigerant sucked into the head-side suction passage (80) of the rear head (33) flows through the second suction passage (52) of the second cylinder (50), the through hole (32a) of the middle plate (32), and the first suction passage (42) of the first cylinder (40).

[0068] The refrigerant is sucked into the first cylinder chamber (41) through the first suction passage (42) and the first communication passage (44). The refrigerant is sucked into the second cylinder chamber (51) through the second suction passage (52) and the second communication passage (54).

[0069] The rear head (33) has a second discharge port (59) penetrating the rear head (33) in the axial direction (see FIG. 4). When the internal pressure of the discharge space in the second cylinder chamber (51) exceeds a predetermined pressure with the rotation of the second roller (56), the refrigerant in the discharge space flows out of the compression mechanism (30) through the second discharge port (59).<First Discharge Valve>

[0070] As illustrated in FIG. 5, a first discharge valve (60) is attached to the front head (31). A tip end portion of the first discharge valve (60) opens and closes the first discharge port (49). A base end portion of the first discharge valve (60) is fixed to the front head (31) with a first fastener (61). The first fastener (61) is, for example, a rivet. The first fastener (61) may be a fastening bolt.

[0071] The front head (31) has a first recess (62). The first discharge valve (60) and the first fastener (61) are housed in the first recess (62).<Second Discharge Valve>

[0072] As illustrated in FIG. 6, a second discharge valve (65) is attached to the rear head (33). A tip end portion of the second discharge valve (65) opens and closes the second discharge port (59). A base end portion of the second discharge valve (65) is fixed to the rear head (33) with a second fastener (66). The second fastener (66) is, for example, a rivet. The second fastener (66) may be a fastening bolt.

[0073] The rear head (33) has a second recess (67). The second discharge valve (65) and the second fastener (66) are housed in the second recess (67).<Fixing Position of First Fastener>

[0074] The front head (31) has the first recess (62) that houses the first discharge valve (60) and the first fastener (61), that is, a portion of the front head (31) where the first fastener (61) is fixed has a reduced thickness. Thus, when the thickness of the front head (31) is reduced particularly on the discharge side where the refrigerant pressure is high, the front head (31) may be distorted.

[0075] To address this, in the present embodiment, the first discharge valve (60) is fixed to a suitable position to reduce the distortion of the front head.

[0076] Specifically, as illustrated in FIG. 3, the first vane chamber (43) has a first center line (L1). The first center line (L1) is a straight line connecting the center (O) of the shaft (25) and the top dead center of the first roller (46) (the position in FIG. 3).

[0077] As illustrated in FIG. 5, the front head (31) is divided into a first region on the side of the first center line (L1) corresponding to the suction space and a second region on the side of the first center line (L1) corresponding to the discharge space when viewed in the axial direction, which is the first direction. The first fastener (61) is disposed in the first region of the front head (31). The first fastener (61) is located at a position that does not overlap with the first suction passage (42) of the first cylinder (40) when viewed in the axial direction.

[0078] As illustrated in FIG. 2, the front head (31), the first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33) are fastened together with the fastening bolt (35). The fastening bolt (35) is tightened to a threaded hole (36) of the front head (31).

[0079] Here, as illustrated in FIG. 5, an angle formed between the first center line (L1) and a straight line connecting the center of the first fastener (61) and the center (O) of the shaft (25) is referred to as a first angle θ1. An angle formed between the first center line (L1) and a straight line connecting the center of the fastening bolt (35) (illustrated as the center of the threaded hole (36) in FIG. 5) and the center (O) of the shaft (25) is referred to as a second angle θ2. The first angle θ1 is set larger than the second angle θ2.

[0080] As illustrated in FIG. 4, the second vane chamber (53) has a second center line (L2). The second center line (L2) is a straight line connecting the center (O) of the shaft (25) and the top dead center of the second roller (56).

[0081] As illustrated in FIG. 6, the rear head (33) is divided into a third region on the side of the second center line (L2) corresponding to the suction space and a fourth region on the side of the second center line (L2) corresponding to the discharge space when viewed in the axial direction, which is the first direction. The second fastener (66) is disposed in the third region of the rear head (33).

[0082] As illustrated in FIG. 5, an angle formed between a straight line connecting the center (O) of the shaft (25) and the center of the tip end portion of the first discharge valve (60) and a straight line connecting the center (O) of the shaft (25) and the center of the first fastener (61) is referred to as a third angle θ3. As illustrated in FIG. 6, an angle formed between a straight line connecting the center (O) of the shaft (25) and the center of the tip end portion of the second discharge valve (65) and a straight line connecting the center (O) of the shaft (25) and the center of the second fastener (66) is referred to as a fourth angle θ4. The third angle θ3 is set to be different from the fourth angle θ4. The third angle θ3 and the fourth angle θ4 may be the same angle.-Advantages of First Embodiment-

[0083] According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0084] According to the present embodiment, the first fastener (61) is located at a position farther from the vane chamber (73) in the circumferential direction than the fastening bolt (35), allowing the first fastener (61) to be fixed at a position further away from the second region where the refrigerant pressure is high.

[0085] According to the present embodiment, the first fastener (61) can be disposed so as not to penetrate the suction passage (72) of the cylinder (70).

[0086] According to the present embodiment, the first fastener (61) and the second fastener (66) can be fixed at suitable positions in a multi-cylinder rotary compressor including the first cylinder (40) and the second cylinder (50).

[0087] According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the third region of the second head (33). This can keep the first head (31) and the second head (33) sufficiently thick in the second region and the fourth region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31) and the second head (33).

[0088] According to the present embodiment, the third angle θ3 and the fourth angle θ4 differ from each other, allowing more flexible arrangement of the first discharge valve (60) and the second discharge valve (65).

[0089] According to the present embodiment, the radial passage (81) and the axial passage (82) are provided in the first head (31) or the second head (33); therefore, the suction passage (72) is not required to penetrate the cylinder (70) outward in the radial direction. This can keep part of the cylinder (70) on the suction passage (72) side sufficiently thick.

[0090] According to the present embodiment, the distortion of the first head (31) can be reduced even when carbon dioxide with a large pressure fluctuation is used as the refrigerant.

[0091] According to the present embodiment, a refrigeration apparatus including the rotary compressor (10) can be provided.«Second Embodiment»

[0092] In the following description, the same reference characters designate the same components as those of the first embodiment, and the description is focused only on the differences.

[0093] As illustrated in FIG. 7, the second vane chamber (53) has a second center line (L2). The second center line (L2) is a straight line connecting the center (O) of the shaft (25) and the top dead center of the second roller (56).

[0094] The rear head (33) is divided into a third region on the side of the second center line (L2) corresponding to the suction space and a fourth region on the side of the second center line (L2) corresponding to the discharge space when viewed in the axial direction, which is the first direction. The second fastener (66) is disposed in the fourth region of the rear head (33).

[0095] The front head (31) is configured in the same manner as that of the first embodiment, and will not be described below.-Advantages of Second Embodiment-

[0096] According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0097] The second fastener (66) is disposed in the fourth region on the side of the second center line (L2) corresponding to the discharge space in consideration of design flexibility.«Other Embodiments»

[0098] While the embodiments and variations have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims. The elements according to embodiments, the variations thereof, and the other embodiments may be combined and replaced with each other. In addition, the expressions of "first," "second," "third," . . . , in the specification and claims are used to distinguish the terms to which these expressions are given, and do not limit the number and order of the terms.INDUSTRIAL APPLICABILITY

[0099] As described above, the present disclosure is useful for a rotary compressor and a refrigeration apparatus.DESCRIPTION OF REFERENCE CHARACTERS

[0100] 1Refrigeration Apparatus 10Rotary Compressor 25Shaft 31Front Head (First Head) 32Middle Plate 33Rear Head (Second Head) 35Fastening Bolt 40First Cylinder 41First Cylinder Chamber 43First Vane Chamber 47First Vane 49First Discharge Port 50Second Cylinder 51Second Cylinder Chamber 53Second Vane Chamber 57Second Vane 59Second Discharge Port 60First Discharge Valve 61First Fastener 65Second Discharge Valve 66Second Fastener 70Cylinder 71Cylinder Chamber 72Suction Passage 73Vane Chamber 76Roller 77Vane 81Radial Passage 82Axial Passage L1First Center Line L2Second Center Line θ1First Angle θ2Second Angle θ3Third Angle θ4Fourth Angle

Examples

first embodiment

-Advantages of First Embodiment-

[0083]According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0084]According to the present embodiment, the first fastener (61) is located at a position farther from the vane chamber (73) in the circumferential direction than the fastening bolt (35), allowing the first fastener (61) to be fixed at a position further away from the second region where the refrigerant pressure is high.

[0085] According to the present embodiment, the first fastener (61) can be disposed so as not to penetrate the suction passage (72) of the cylinder (70).

[0086]According to the present embodiment, the first fastener (61) and the second fastener (66) can be fixed at suitable positions in a multi-cylinder rotary compressor including the first cyl...

« second embodiment »

«Second Embodiment»

[0092]In the following description, the same reference characters designate the same components as those of the first embodiment, and the description is focused only on the differences.

[0093]As illustrated in FIG. 7, the second vane chamber (53) has a second center line (L2). The second center line (L2) is a straight line connecting the center (O) of the shaft (25) and the top dead center of the second roller (56).

[0094]The rear head (33) is divided into a third region on the side of the second center line (L2) corresponding to the suction space and a fourth region on the side of the second center line (L2) corresponding to the discharge space when viewed in the axial direction, which is the first direction. The second fastener (66) is disposed in the fourth region of the rear head (33).

[0095]The front head (31) is configured in the same manner as that of the first embodiment, and will not be described below.

second embodiment

-Advantages of Second Embodiment-

[0096]According to the present embodiment, the first fastener (61) is disposed in the first region of the first head (31) to maintain a sufficient thickness of the first head (31) in the second region where the refrigerant pressure is high, thereby reducing the distortion of the first head (31).

[0097]The second fastener (66) is disposed in the fourth region on the side of the second center line (L2) corresponding to the discharge space in consideration of design flexibility.

Claims

1. A rotary compressor, comprising: a shaft (25) extending in a first direction; a first head (31) configured to rotatably support the shaft (25) and having a first discharge port (49) through which a refrigerant is discharged; a cylinder (70) having a cylinder chamber (71) and disposed adjacent to the first head (31); a roller (76) fixed to the shaft (25) and configured to eccentrically rotate in the cylinder chamber (71); a vane (77) configured to partition the cylinder chamber (71) into a suction space and a discharge space; a second head (33) configured to rotatably support the shaft (25) and disposed on an opposite side of the cylinder (70) from the first head (31); a first discharge valve (60) configured to open and close the first discharge port (49); and a first fastener (61) configured to fix a base end portion of the first discharge valve (60) to the first head (31), the cylinder (70) having a vane chamber (73) configured to house the vane (77), the vane chamber (73) having a first center line (L1), the first head (31) being divided into a first region on a side of the first center line (L1) corresponding to the suction space and a second region on a side of the first center line (L1) corresponding to the discharge space when viewed from the first direction, the first fastener (61) being disposed in the first region of the first head (31).

2. The rotary compressor of claim 1, further comprising: a fastening bolt (35) configured to fasten the first head (31), the cylinder (70), and the second head (33), wherein a first angle θ1 formed between the first center line (L1) and a straight line connecting a center of the first fastener (61) and a center (O) of the shaft (25) is larger than a second angle θ2 formed between the first center line (L1) and a straight line connecting a center of the fastening bolt (35) and the center (O) of the shaft (25).

3. The rotary compressor of claim 1 or 2, wherein the first fastener (61) is located at a position that does not overlap with a suction passage (72) of the cylinder (70) when viewed in the first direction.

4. The rotary compressor of any one of claims 1 to 3, wherein the cylinder (70) includes a first cylinder (40) having a first cylinder chamber (41) and a second cylinder (50) having a second cylinder chamber (51), the vane (77) includes a first vane (47) and a second vane (57), the first cylinder (40) includes a first vane chamber (43) configured to house the first vane (47) and having the first center line (L1), the second cylinder (50) includes a second vane chamber (53) configured to house the second vane (57) and having a second center line (L2), the second head (33) has a second discharge port (59) through which the refrigerant is discharged, and the rotary compressor further includes: a middle plate (32) disposed between the first cylinder (40) and the second cylinder (50); a second discharge valve (65) configured to open and close the second discharge port (59); and a second fastener (66) configured to fix a base end portion of the second discharge valve (65) to the second head (33).

5. The rotary compressor of claim 4, wherein the second head (33) is divided into a third region on a side of the second center line (L2) corresponding to the suction space and a fourth region on a side of the second center line (L2) corresponding to the discharge space when viewed from the first direction, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the fourth region of the second head (33).

6. The rotary compressor of claim 4, wherein the second head (33) is divided into a third region on a side of the second center line (L2) corresponding to the suction space and a fourth region on a side of the second center line (L2) corresponding to the discharge space when viewed from the first direction, the first fastener (61) is disposed in the first region of the first head (31), and the second fastener (66) is disposed in the third region of the second head (33).

7. The rotary compressor of claim 6, wherein a third angle θ3 formed between a straight line connecting a center (O) of the shaft (25) and a center of a tip end portion of the first discharge valve (60) and a straight line connecting the center (O) of the shaft (25) and a center of the first fastener (61) is different from a fourth angle θ4 formed between a straight line connecting the center (O) of the shaft (25) and a center of a tip end portion of the second discharge valve (65) and a straight line connecting the center (O) of the shaft (25) and a center of the second fastener (66).

8. The rotary compressor of any one of claims 1 to 7, wherein the first head (31) or the second head (33) includes a radial passage (81) extending in a radial direction and an axial passage (82) communicating with the radial passage (81) and extending in an axial direction, and a suction passage (72) of the cylinder (70) communicates with the axial passage (82).

9. The rotary compressor of any one of claims 1 to 8, wherein the refrigerant is carbon dioxide.

10. A refrigeration apparatus comprising the rotary compressor (10) of any one of claims 1 to 9.

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