Rotary compressor and refrigeration apparatus

Abstract

In the present invention, a first oil supply passage (60) has: a first axial passage (61) that is disposed offset radially from the rotation center of a drive shaft (25) and extends axially from a storage space (36); and a first connection passage (62) that connects the first axial passage (61) and a sliding surface of a first sliding member (65). A second oil supply passage (70) has: a second axial passage (71) that is disposed offset radially from the rotation center of the drive shaft (25) and extends axially, from the storage space (36), at a position separated from the first axial passage (61); and a second connection passage (72) that connects the second axial passage (71) and a sliding surface of a second sliding member (75).

Description

Rotary compressor and refrigeration device

[0001] The present disclosure relates to a rotary compressor and a refrigeration device.

[0002] Patent Document 1 discloses a compressor including a compression mechanism disposed in a sealed container and a drive shaft (rotating shaft) that drives the compression mechanism. The drive shaft is provided with an oil supply passage extending in the axial direction. An oil supply pump is attached to the lower end of the drive shaft. Oil stored in the lower part of the sealed container is supplied by the oil supply pump through the oil supply passage of the drive shaft to each sliding part of the compression mechanism.

[0003] Japanese Patent Application Laid-Open No. 2022-072807

[0004] Here, there is a problem in that centrifugal force is applied to the drive shaft as the compression mechanism is rotated, which increases the axial deflection of the drive shaft.

[0005] Specifically, in order to pump oil by centrifugal pumping action, the centrifugal pump must be structurally provided with a small diameter portion on the inlet side and a large diameter portion on the outlet side with a larger hole diameter than the small diameter portion.

[0006] In the case of a conventional compressor, the small-diameter portion on the inlet side of the centrifugal pump corresponds to the suction port that opens in a tapered shape at the bottom end of the centrifugal pump, and the large-diameter portion on the outlet side corresponds to the circular axial passage that extends axially through the center of the drive shaft. Therefore, in the conventional compressor, a relatively large-diameter circular axial passage is provided in the center of the drive shaft, which may reduce the rigidity of the drive shaft.

[0007] An object of the present disclosure is to ensure the rigidity of the drive shaft and suppress axial deflection of the drive shaft.

[0008] A first aspect of the present disclosure is a rotary compressor including: a casing (11) having an oil reservoir (18) at its bottom; a compression mechanism (30) accommodated in the casing (11); a drive shaft (25) that rotationally drives the compression mechanism (30); and an oil pump (35) that sucks up oil from the oil reservoir (18) toward a storage space (36) provided below the drive shaft (25), wherein the rotary compressor includes: a first sliding member (65) that slides on an outer circumferential surface of the drive shaft (25); and a second sliding member (75) that is disposed at an interval in the axial direction from the first sliding member (65) and slides on an outer circumferential surface of the drive shaft (25). a first oil supply passage (60) having a first axial passage (61) disposed radially offset from the rotation center of the drive shaft (25) and extending in the axial direction from the storage space (36), and a first connecting passage (62) connecting the first axial passage (61) and the sliding surface of the first sliding member (65); and a second oil supply passage (70) having a second axial passage (71) disposed radially offset from the rotation center of the drive shaft (25) and extending in the axial direction from the storage space (36) at a position separated from the first axial passage (61), and a second connecting passage (72) connecting the second axial passage (71) and the sliding surface of the second sliding member (75).

[0009] In the first aspect, in each of the first oil supply passage (60) and the second oil supply passage (70), a distance from the center of rotation of the drive shaft (25) to the inner wall surface at the point farthest radially from the center of rotation of the drive shaft (25) is ensured, thereby achieving a centrifugal pump action, and the rigidity of the drive shaft (25) is improved, thereby reducing axial deflection.

[0010] Specifically, in a configuration in which the first oil supply passage (60) and the second oil supply passage (70) are radially offset from the rotation center of the drive shaft (25), the distance from the rotation center of the drive shaft (25) to the inner wall surface at the point farthest in the radial direction can be ensured to be equal to the radius of the axial passage in the case where one circular axial passage is provided, thereby achieving a centrifugal pump action. Furthermore, since a solid portion is present in the drive shaft (25) between the first oil supply passage (60) and the second oil supply passage (70), the rigidity of the drive shaft (25) can be improved and axial deflection can be reduced compared to a case in which a hollow portion is present in the center of the drive shaft (25).

[0011] In a second aspect of the present disclosure, in the rotary compressor of the first aspect, the oil pump (35) has an intake port (35a) that opens downward and draws in oil, and at least a portion of each opening of the first axial passage (61) and the second axial passage (71) on the side of the storage space (36) is positioned radially outward from the peripheral portion of the intake port (35a).

[0012] In the second aspect, by positioning at least a portion of the openings of the first axial passage (61) and the second axial passage (71) on the storage space (36) side radially outward from the peripheral portion of the suction port (35a), the oil sucked into the storage space (36) from the suction port (35a) of the oil pump (35) can be sucked up by centrifugal pump action.

[0013] A third aspect of the present disclosure is the rotary compressor of the first or second aspect, wherein the drive shaft (25) has a main shaft portion (26) and an eccentric portion (29) eccentric from the axis of the main shaft portion (26) by a predetermined amount, and further includes an upper bearing member (31) that slides on an upper bearing surface (26a) of the main shaft portion (26) above the eccentric portion (29), a lower bearing member (33) that slides on a lower bearing surface (26b) of the main shaft portion (26) below the eccentric portion (29), and a piston (38) that slides on an outer circumferential surface of the eccentric portion (29), and the first sliding member (65) is any one of the upper bearing member (31), the lower bearing member (33), or the piston (38). the second sliding member (75) is any one of the upper bearing member (31), the lower bearing member (33), and the piston (38) which is different from the first sliding member (65); the first oil supply passage (60) is in communication with at least one of the upper bearing surface (26a) of the main shaft portion (26), the lower bearing surface (26b) of the main shaft portion (26), and the outer peripheral surface of the eccentric portion (29); and the second oil supply passage (70) is in communication with at least one of the upper bearing surface (26a) of the main shaft portion (26), the lower bearing surface (26b) of the main shaft portion (26), and the outer peripheral surface of the eccentric portion (29), which is different from the surface to which the first oil supply passage (60) is in communication.

[0014] In the third aspect, oil can be supplied from the first oil supply passage (60) or the second oil supply passage (70) to the upper bearing surface (26a), the lower bearing surface (26b) of the main shaft portion (26), or the outer peripheral surface of the eccentric portion (29).

[0015] A fourth aspect of the present disclosure is the rotary compressor of the third aspect, wherein the first oil supply passage (60) or the second oil supply passage (70) is connected to the lower bearing surface (26b) of the main shaft portion (26) and an outer peripheral surface of the eccentric portion (29).

[0016] In the fourth aspect, by using a common oil supply passage to supply oil to the lower bearing surface (26b) of the main shaft portion (26) and the outer peripheral surface of the eccentric portion (29), the overall number of oil supply passages can be reduced and the rigidity of the drive shaft (25) can be improved.

[0017] A fifth aspect of the present disclosure is the rotary compressor of the third aspect, wherein the first oil supply passage (60) or the second oil supply passage (70) is connected to the upper bearing surface (26a) of the main shaft portion (26) and an outer peripheral surface of the eccentric portion (29).

[0018] In the fifth aspect, by using a common oil supply passage to supply oil to the upper bearing surface (26a) of the main shaft portion (26) and the outer peripheral surface of the eccentric portion (29), the number of oil supply passages can be reduced overall, and the rigidity of the drive shaft (25) can be improved.

[0019] A sixth aspect of the present disclosure is the rotary compressor of the third aspect, wherein the eccentric portion (29) includes a first eccentric portion (27) and a second eccentric portion (28) arranged axially spaced apart from the first eccentric portion (27), the piston (38) includes a first piston (45) sliding on an outer peripheral surface of the first eccentric portion (27) and a second piston (55) sliding on an outer peripheral surface of the second eccentric portion (28), the first oil supply passage (60) communicates with the outer peripheral surface of the first eccentric portion (27), and the second oil supply passage (70) communicates with the outer peripheral surface of the second eccentric portion (28).

[0020] In the sixth aspect, oil is supplied from the first oil supply passage (60) to the outer peripheral surface of the first eccentric portion (27), while oil is supplied from the second oil supply passage (70) to the outer peripheral surface of the second eccentric portion (28), thereby ensuring a sufficient amount of oil to be supplied to the outer peripheral surfaces of the first eccentric portion (27) and the second eccentric portion (28).

[0021] A seventh aspect of the present disclosure is the rotary compressor of any one of the first to sixth aspects, wherein the length of the first axial passage (61) and the length of the second axial passage (71) are different from each other.

[0022] In the seventh aspect, for example, when the first sliding member (65) is disposed above the second sliding member (75), the length of the second axial passage (71) is made shorter than the length of the first axial passage (61), thereby improving the rigidity of the drive shaft (25) compared to when the first axial passage (61) has the same length as the second axial passage (71).

[0023] An eighth aspect of the present disclosure is the rotary compressor of the third aspect, wherein the first oil supply passage (60) communicates with the upper bearing surface (26a) of the main shaft portion (26), the second oil supply passage (70) communicates with the lower bearing surface (26b) of the main shaft portion (26), and the length of the first axial passage (61) is longer than the length of the second axial passage (71).

[0024] In the eighth aspect, the length of the second axial passage (71) that supplies oil to the lower bearing surface (26b) of the main shaft portion (26) is made shorter than the length of the first axial passage (61) that supplies oil to the upper bearing surface (26a) of the main shaft portion (26). This improves the rigidity of the drive shaft (25) compared to when the first axial passage (61) is the same length as the second axial passage (71).

[0025] A ninth aspect of the present disclosure is a refrigeration system including a rotary compressor (10) according to any one of the first to eighth aspects and a refrigerant circuit (1a) through which a refrigerant compressed by the rotary compressor (10) flows.

[0026] In the ninth aspect, a refrigeration system can be provided, which includes a rotary compressor (10) and a refrigerant circuit (1a).

[0027] Fig. 1 is a refrigerant circuit diagram showing the configuration of a refrigeration system of this embodiment. Fig. 2 is a longitudinal cross-sectional view showing the configuration of a rotary compressor. Fig. 3 is a plan cross-sectional view showing the configuration of a first cylinder and a first piston. Fig. 4 is a plan cross-sectional view showing the configuration of a second cylinder and a second piston. Fig. 5 is a longitudinal cross-sectional view showing the configuration of a first oil supply passage and a second oil supply passage.

[0028] As shown in Fig. 1, the rotary compressor (10) is provided in a refrigeration system (1). The refrigeration system (1) has a refrigerant circuit (1a) filled with a refrigerant. The refrigerant circuit (1a) has a rotary compressor (10), a radiator (3), a pressure reduction mechanism (4), and an evaporator (5). The pressure reduction mechanism (4) is, for example, an expansion valve. The refrigerant circuit (1a) performs a vapor compression refrigeration cycle.

[0029] The refrigeration system (1) is an air conditioning system. The air conditioning system may be a cooling-only system, a heating-only system, or an air conditioning system that switches between cooling and heating. In this case, the air conditioning system has a switching mechanism (e.g., a four-way switching valve) that switches the refrigerant circulation direction. The refrigeration system (1) may be a water heater, a chiller unit, a cooling system that cools the air inside a storage unit, or the like. The cooling system cools the air inside a refrigerator, a freezer, a container, or the like.

[0030] 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 inside the casing (11).

[0031] The casing (11) is a vertically long, cylindrical, sealed container. A suction connection pipe (16) is fixed to and passes through the body of the casing (11). An outlet pipe (15) of an accumulator (not shown) is connected to the suction connection pipe (16). A discharge pipe (17) is fixed to and passes through the upper part of the casing (11).

[0032] An oil reservoir (18) is provided at the bottom of the casing (11). Oil is stored in the oil reservoir (18). The oil is used to lubricate the sliding parts of the compression mechanism (30) and the drive shaft (25).

[0033] <Drive Mechanism> The drive mechanism (20) is housed inside the casing (11). The drive mechanism (20) has a motor (21) and a drive shaft (25). The motor (21) is disposed above the compression mechanism (30). The motor (21) has a stator (22) and a rotor (23).

[0034] The stator (22) is fixed to the inner peripheral surface of the casing (11). The rotor (23) passes through the interior of the stator (22) in the vertical direction. A drive shaft (25) is fixed to the interior of the axial center of the rotor (23). When the motor (21) is energized, the drive shaft (25) is rotated together with the rotor (23).

[0035] The drive shaft (25) is disposed on the axis of the casing (11). A centrifugal oil pump (35) is provided at the lower part of the drive shaft (25). A suction port (35a) opens at the lower part of the oil pump (35). A storage space (36) is provided at the lower part of the drive shaft (25) above the oil pump (35).

[0036] A first oil supply passage (60) and a second oil supply passage (70) are formed inside the drive shaft (25). Openings of the first axial passage (61) and the second axial passage (71) on the storage space (36) side are located radially outward from the peripheral edge of the suction port (35a) and communicate with the storage space (36).

[0037] 2, the entire openings of the first axial passage (61) and the second axial passage (71) on the storage space (36) side are arranged radially outward from the peripheral edge of the suction opening (35a), but the present invention is not limited to this. For example, it is sufficient that at least a part of the openings of the first axial passage (61) and the second axial passage (71) on the storage space (36) side are arranged radially outward from the peripheral edge of the suction opening (35a).

[0038] As the drive shaft (25) rotates, the oil pump (35) sucks up oil stored in the oil reservoir (18) toward the storage space (36). The oil stored in the storage space (36) is supplied to the compression mechanism (30) and sliding parts of the drive shaft (25) through a first oil supply passage (60) and a second oil supply passage (70). The first oil supply passage (60) and the second oil supply passage (70) will be described in detail later.

[0039] The drive shaft (25) has a main shaft portion (26) and an eccentric portion (29). The eccentric portion (29) includes a first eccentric portion (27) and a second eccentric portion (28). The second eccentric portion (28) is disposed axially apart from the first eccentric portion (27).

[0040] 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.

[0041] The main shaft portion (26) above the first eccentric portion (27) is rotatably supported by a front head (31) described later. The main shaft portion (26) below the second eccentric portion (28) is rotatably supported by a rear head (33) described later.

[0042] <Compression Mechanism> 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). The compression mechanism (30) has a front head (31), a middle plate (32), a rear head (33), a cylinder (37), and a piston (38). The cylinder (37) includes a first cylinder (40) and a second cylinder (50). The piston (38) includes a first piston (45) and a second piston (55).

[0043] The front head (31), the first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33) are stacked in order from top to bottom and fixed by fastening bolts (34).

[0044] The front head (31) is fixed to the body of the casing (11). The front head (31) is stacked on top of the first cylinder (40). The front head (31) is arranged so as to cover the first cylinder chamber (41) of the first cylinder (40) from above. The main shaft portion (26) of the drive shaft (25) is inserted into the center of the front head (31). The front head (31) rotatably supports the drive shaft (25). A first discharge passage (49) (see FIG. 3) is formed in the front head (31) and passes through it in the axial direction.

[0045] The first cylinder (40) is formed of a flat, substantially annular member. As shown in Fig. 3, the first cylinder (40) has a first cylinder chamber (41), a first suction passage (42), and a first blade storage chamber (43).

[0046] The first cylinder chamber (41) is provided in the center of the first cylinder (40). The first suction passage (42) extends from the inner wall surface of the first cylinder chamber (41) toward the outside in the radial direction of the first cylinder (40). The first suction passage (42) opens to the outer surface of the first cylinder (40). The suction connection pipe (16) is connected to the inflow end of the first suction passage (42). The outflow end of the first suction passage (42) communicates with the first cylinder chamber (41).

[0047] The first cylinder chamber (41) accommodates a first piston (45). The first piston (45) has a first piston body (46) and a first blade (47). The first piston body (46) is formed in an annular shape. The first eccentric portion (27) of the drive shaft (25) is fitted inside the first piston body (46). The first blade (47) extends radially outward from the first piston body (46). The first blade (47) is supported by a pair of first bushings (48). The interior of the first cylinder chamber (41) is partitioned into a low-pressure chamber and a high-pressure chamber by the first blade (47).

[0048] The first piston (45) rotates eccentrically in the first cylinder chamber (41) as the drive shaft (25) is driven to rotate. As the volume of the low-pressure chamber increases gradually with the eccentric rotation of the first piston (45), the refrigerant flowing through the suction connection pipe (16) is sucked into the low-pressure chamber through the first suction passage (42).

[0049] Next, when the low-pressure chamber is isolated from the first suction passage (42), the isolated space forms a high-pressure chamber. As the volume of the high-pressure chamber gradually decreases, the internal pressure of the high-pressure chamber increases. When the internal pressure of the high-pressure chamber exceeds a predetermined pressure, the refrigerant in the high-pressure chamber flows out of the compression mechanism (30) through the first discharge passage (49). This 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), etc. The high-pressure refrigerant that has flowed out above the motor (21) is sent to the refrigerant circuit through the discharge pipe (17).

[0050] The first blade housing chamber (43) is provided at a position radially outwardly spaced from the first cylinder chamber (41). The first blade housing chamber (43) penetrates the first cylinder (40) in the thickness direction. The first blade housing chamber (43) houses the tip end of the first blade (47). The first blade (47) swings in the first blade housing chamber (43) in association with the eccentric rotation of the first piston body (46).

[0051] As shown in Fig. 2, the middle plate (32) is sandwiched between the first cylinder (40) and the second cylinder (50). The middle plate (32) is arranged so as to cover the first cylinder chamber (41) of the first cylinder (40) from below. The middle plate (32) is arranged so as to cover the second cylinder chamber (51) of the second cylinder (50) from above.

[0052] The second cylinder (50) is formed of a flat, substantially annular member. As shown in Figure 4, the second cylinder (50) has a second cylinder chamber (51), a second suction passage (52), and a second blade storage chamber (53).

[0053] The second cylinder chamber (51) is provided in the center of the second cylinder (50). The second suction passage (52) extends from the inner wall surface of the second cylinder chamber (51) toward the outside in the radial direction of the second cylinder (50). The second suction passage (52) opens to the outer surface of the second cylinder (50). The inflow end of the second suction passage (52) is connected to the suction connection pipe (16). The outflow end of the second suction passage (52) communicates with the second cylinder chamber (51).

[0054] The second cylinder chamber (51) accommodates a second piston (55). The second piston (55) has a second piston body (56) and a second blade (57). The second piston body (56) is formed in an annular shape. The second eccentric portion (28) of the drive shaft (25) is fitted inside the second piston body (56). The second blade (57) extends radially outward from the second piston body (56). The second blade (57) is supported by a pair of second bushings (58). The interior of the second cylinder chamber (51) is divided into a low-pressure chamber and a high-pressure chamber by the second blade (57).

[0055] The operation of the second piston (55) is substantially the same as the operation of the first piston (45), and therefore, a description thereof will be omitted.

[0056] The second blade accommodating chamber (53) is provided at a position radially outwardly spaced from the second cylinder chamber (51). The second blade accommodating chamber (53) penetrates the second cylinder (50) in the thickness direction. The tip of the second blade (57) is accommodated in the second blade accommodating chamber (53). The second blade (57) swings in the second blade accommodating chamber (53) in association with the eccentric rotation of the second piston body (56).

[0057] As shown in FIG. 2 , the rear head (33) is stacked below the second cylinder (50). The rear head (33) is arranged so as to cover the second cylinder chamber (51) of the second cylinder (50) from below. The main shaft portion (26) of the drive shaft (25) is inserted into the center of the rear head (33). The rear head (33) rotatably supports the drive shaft (25). A second discharge passage (59) (see FIG. 4 ) is formed in the rear head (33) and passes through it in the axial direction. When the internal pressure of the high-pressure chamber of the second cylinder chamber (51) exceeds a predetermined pressure, the refrigerant in the high-pressure chamber flows out of the compression mechanism (30) through the second discharge passage (59).

[0058] <Oil Supply Passage> Incidentally, a centrifugal force is applied to the drive shaft (25) as the compression mechanism (30) is rotated, which causes a problem of increased axial deflection of the drive shaft (25).

[0059] Therefore, the inventors of the present application have focused on the oil supply passage, which is a factor that reduces the rigidity of the drive shaft (25), and have investigated ways to increase the rigidity of the drive shaft (25) by devising the shape of the oil supply passage.

[0060] As shown in Figure 5, the main shaft portion (26) has an upper bearing surface (26a) and a lower bearing surface (26b). The upper bearing surface (26a) is provided above the first eccentric portion (27) of the main shaft portion (26). The lower bearing surface (26b) is provided below the second eccentric portion (28) of the main shaft portion (26).

[0061] The main shaft portion (26) is rotatably supported by a front head (31) serving as an upper bearing member and a rear head (33) serving as a lower bearing member. The front head (31) slides on an upper bearing surface (26a) of the main shaft portion (26). The rear head (33) slides on a lower bearing surface (26b) of the main shaft portion (26).

[0062] The first piston (45) slides on the outer peripheral surface of the first eccentric part (27), and the second piston (55) slides on the outer peripheral surface of the second eccentric part (28).

[0063] The drive shaft (25) is provided with a first oil supply passage (60) and a second oil supply passage (70). The first oil supply passage (60) has a first axial passage (61) and a first connecting passage (62). The second oil supply passage (70) has a second axial passage (71) and a second connecting passage (72).

[0064] The first axial passage (61) is disposed radially offset from the rotation center of the drive shaft (25) and extends axially from the storage space (36). The first connecting passage (62) connects the first axial passage (61) and the sliding surface of the first sliding member (65).

[0065] The first sliding member (65) slides on the outer peripheral surface of the drive shaft (25). The first sliding member (65) is any one of the front head (31), the rear head (33), the first piston (45), and the second piston (55). In the example shown in Fig. 5, the first sliding member (65) includes the front head (31) and the first piston (45).

[0066] The first oil supply passage (60) communicates with at least one of the upper bearing surface (26a) of the main shaft portion (26), the lower bearing surface (26b) of the main shaft portion (26), the outer peripheral surface of the first eccentric portion (27), and the second eccentric portion (28). In the example shown in Fig. 5, the first oil supply passage (60) has two first connection passages (62). The two first connection passages (62) communicate with the upper bearing surface (26a) of the main shaft portion (26) and the outer peripheral surface of the first eccentric portion (27), respectively.

[0067] The second sliding member (75) is disposed at an axial distance from the first sliding member (65). The second sliding member (75) slides on the outer peripheral surface of the drive shaft (25). The second sliding member (75) is any one of the front head (31), the rear head (33), the first piston (45), and the second piston (55), which is different from the first sliding member (65). In the example shown in FIG. 5 , the second sliding member (75) includes the second piston (55) and the rear head (33).

[0068] The second axial passage (71) is disposed radially offset from the rotation center of the drive shaft (25) and extends axially from the storage space (36) at a position spaced apart from the first axial passage (61). The second connecting passage (72) connects the second axial passage (71) and the sliding surface of the second sliding member (75).

[0069] The second oil supply passage (70) communicates with at least one of the upper bearing surface (26a) of the main shaft portion (26), the lower bearing surface (26b) of the main shaft portion (26), the outer peripheral surface of the first eccentric portion (27), and the outer peripheral surface of the second eccentric portion (28), which is different from the surface with which the first oil supply passage (60) communicates. In the example shown in Fig. 5, the second oil supply passage (70) has two second connection passages (72). The two second connection passages (72) communicate with the lower bearing surface (26b) of the main shaft portion (26) and the outer peripheral surface of the second eccentric portion (28), respectively.

[0070] It should be noted that the sliding surfaces connecting the first oil supply passage (60) and the second oil supply passage (70) are not limited to the configuration shown in Fig. 5. For example, the first oil supply passage (60) and the second oil supply passage (70) may be connected to sliding surfaces different from those shown in Fig. 5.

[0071] Here, the length of the first axial passage (61) is different from the length of the second axial passage (71). In the example shown in Fig. 5, the front head (31) and the first piston (45) serving as the first sliding member (65) are disposed above the second piston (55) and the rear head (33) serving as the second sliding member (75), and therefore the length of the first axial passage (61) is made longer than the length of the second axial passage (71).

[0072] -Effects of the embodiment- According to the present embodiment, in each of the first oil supply passage (60) and the second oil supply passage (70), a distance from the center of rotation of the drive shaft (25) to the inner wall surface at the point farthest radially is ensured, thereby achieving a centrifugal pump action, and the rigidity of the drive shaft (25) can be improved to reduce axial deflection.

[0073] Specifically, in a configuration in which the first oil supply passage (60) and the second oil supply passage (70) are radially offset from the rotation center of the drive shaft (25), the distance from the rotation center of the drive shaft (25) to the inner wall surface at the point farthest in the radial direction can be ensured to be equal to the radius of the axial passage in the case where one circular axial passage is provided, thereby achieving a centrifugal pump action. Furthermore, since a solid portion is present in the drive shaft (25) between the first oil supply passage (60) and the second oil supply passage (70), the rigidity of the drive shaft (25) can be improved and axial deflection can be reduced compared to a case in which a hollow portion is present in the center of the drive shaft (25).

[0074] According to this embodiment, by positioning at least a portion of the openings of the first axial passage (61) and the second axial passage (71) on the storage space (36) side radially outward from the peripheral edge of the suction port (35a), the oil sucked into the storage space (36) from the suction port (35a) of the oil pump (35) can be sucked up by centrifugal pump action.

[0075] According to this embodiment, oil can be supplied from the first oil supply passage (60) or the second oil supply passage (70) to the upper bearing surface (26a), the lower bearing surface (26b) of the main shaft portion (26), or the outer peripheral surface of the eccentric portion (29).

[0076] According to this embodiment, by using the oil supply passage to supply oil to both the lower bearing surface (26b) of the main shaft portion (26) and the outer peripheral surface of the eccentric portion (29), the overall number of oil supply passages can be reduced and the rigidity of the drive shaft (25) can be improved.

[0077] According to this embodiment, by using the oil supply passage to supply oil to both the upper bearing surface (26a) of the main shaft portion (26) and the outer peripheral surface of the eccentric portion (29), the number of oil supply passages can be reduced overall, and the rigidity of the drive shaft (25) can be improved.

[0078] According to this embodiment, oil is supplied from the first oil supply passage (60) to the outer peripheral surface of the first eccentric portion (27), while oil is supplied from the second oil supply passage (70) to the outer peripheral surface of the second eccentric portion (28), thereby ensuring a sufficient amount of oil to be supplied to the outer peripheral surfaces of the first eccentric portion (27) and the second eccentric portion (28).

[0079] According to the present embodiment, the length of the first axial passage (61) and the length of the second axial passage (71) are different from each other. For example, when the first sliding member (65) is disposed above the second sliding member (75), the length of the second axial passage (71) is made shorter than the length of the first axial passage (61). This improves the rigidity of the drive shaft (25) compared to when the first axial passage (61) has the same length as the second axial passage (71).

[0080] According to this embodiment, the length of the second axial passage (71) that supplies oil to the lower bearing surface (26b) of the main shaft portion (26) is made shorter than the length of the first axial passage (61) that supplies oil to the upper bearing surface (26a) of the main shaft portion (26). This improves the rigidity of the drive shaft (25) compared to when the first axial passage (61) is the same length as the second axial passage (71).

[0081] According to the present embodiment, a refrigeration system (1) is provided, which includes a rotary compressor (10) and a refrigerant circuit (1a) through which the refrigerant compressed by the rotary compressor (10) flows. This makes it possible to provide a refrigeration system (1) including the rotary compressor (10).

[0082] Other Embodiments The above-described embodiment may be configured as follows.

[0083] In the present embodiment, the drive shaft (25) has been described as having the first eccentric portion (27) and the second eccentric portion (28), but the present invention is not limited to this.

[0084] For example, the drive shaft (25) may have a main shaft portion (26) and one eccentric portion (29). In this case, for example, the first oil supply passage (60) may be connected to the outer peripheral surfaces of the upper bearing surface (26a) and the lower bearing surface (26b) of the main shaft portion (26), and the second oil supply passage (70) may be connected to the outer peripheral surface of the eccentric portion (29).

[0085] The drive shaft (25) may also be configured to have three eccentric portions (29). In this case, for example, a first oil supply passage (60), a second oil supply passage (70), and a third oil supply passage (not shown) may be provided on the drive shaft (25), with the first oil supply passage (60) communicating with the outer peripheral surface of the first eccentric portion (27), the second oil supply passage (70) communicating with the outer peripheral surface of the second eccentric portion (28), and the third oil supply passage communicating with the outer peripheral surface of the third eccentric portion (not shown).

[0086] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and detail are possible without departing from the spirit and scope of the claims. Furthermore, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate. Furthermore, the terms "first," "second," "third," etc. in the specification and claims are used to distinguish between terms to which these terms are attached, and do not limit the number or order of those terms.

[0087] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for rotary compressors and refrigeration devices.

[0088] REFRIGERATION SYSTEM 1a REFRIGERATOR CIRCUIT 10 ROTARY COMPRESSOR 11 CASING 18 OIL RESERVOIR 25 DRIVE SHAFT 26 MAIN SHAFT 26a UPPER BEARING SURFACE 26b LOWER BEARING SURFACE 27 FIRST ECCENTRIC PORTION 28 SECOND ECCENTRIC PORTION 29 ECCENTRIC PORTION 30 COMPRESSION MECHANISM 31 FRONT HEAD (UPPER BEARING MEMBER) 33 REAR HEAD (LOWER BEARING MEMBER) 35 OIL PUMP 35a SUCTION PORTION 36 STORAGE SPACE 38 PISTON 45 FIRST PISTON 55 SECOND PISTON 60 FIRST OIL SUPPLY PASSAGE 61 FIRST AXIAL PATH 62 FIRST CONNECTING PASSAGE 65 FIRST SLIDING MEMBER 70 SECOND OIL SUPPLY PASSAGE 71 SECOND AXIAL PATH 72 SECOND CONNECTING PASSAGE 75 SECOND SLIDING MEMBER

Claims

1. A rotary compressor comprising: a casing (11) having an oil reservoir (18) at its bottom; a compression mechanism (30) accommodated in the casing (11); a drive shaft (25) for rotatably driving the compression mechanism (30); and an oil pump (35) for drawing up oil from the oil reservoir (18) toward a storage space (36) provided at a lower portion of the drive shaft (25); wherein the rotary compressor comprises: a first sliding member (65) sliding against an outer circumferential surface of the drive shaft (25); and a second sliding member (75) disposed axially spaced from the first sliding member (65) and sliding against an outer circumferential surface of the drive shaft (25); and the drive shaft (25) is provided with: a first oil supply passage (60) having a first axial passage (61) arranged radially offset from the rotation center of the drive shaft (25) and extending in the axial direction from the storage space (36) and a first connecting passage (62) connecting the first axial passage (61) and a sliding surface of the first sliding member (65); and a second oil supply passage (70) having a second axial passage (71) arranged radially offset from the rotation center of the drive shaft (25) and extending in the axial direction from the storage space (36) at a position away from the first axial passage (61), and a second connecting passage (72) connecting the second axial passage (71) and a sliding surface of the second sliding member (75).

2. The rotary compressor according to claim 1, wherein the oil pump (35) has a suction port (35a) opening downward to suck in oil, and at least a portion of each of the openings of the first axial passage (61) and the second axial passage (71) on the side of the storage space (36) is positioned radially outward from a peripheral portion of the suction port (35a).

3. The rotary compressor according to claim 1 or 2, wherein the drive shaft (25) has a main shaft portion (26) and an eccentric portion (29) eccentric from the axis of the main shaft portion (26) by a predetermined amount, and further comprises: an upper bearing member (31) sliding against an upper bearing surface (26a) of the main shaft portion (26) above the eccentric portion (29); a lower bearing member (33) sliding against a lower bearing surface (26b) of the main shaft portion (26) below the eccentric portion (29); and a piston (38) sliding against an outer circumferential surface of the eccentric portion (29); and the first sliding member (65) is any one of the upper bearing member (31), the lower bearing member (33), or the piston (38), the second sliding member (75) is any one of the upper bearing member (31), the lower bearing member (33), or the piston (38), which is different from the first sliding member (65); the first oil supply passage (60) is in communication with at least one of the upper bearing surface (26a) of the main shaft portion (26), the lower bearing surface (26b) of the main shaft portion (26), and an outer circumferential surface of the eccentric portion (29); and the second oil supply passage (70) is in communication with at least one of the upper bearing surface (26a) of the main shaft portion (26), the lower bearing surface (26b) of the main shaft portion (26), and the outer circumferential surface of the eccentric portion (29), which is different from a surface with which the first oil supply passage (60) is in communication.

4. A rotary compressor according to claim 3, wherein the first oil supply passage (60) or the second oil supply passage (70) communicates with the lower bearing surface (26b) of the main shaft portion (26) and with the outer circumferential surface of the eccentric portion (29).

5. A rotary compressor according to claim 3, wherein the first oil supply passage (60) or the second oil supply passage (70) communicates with the upper bearing surface (26a) of the main shaft portion (26) and with the outer circumferential surface of the eccentric portion (29).

6. A rotary compressor according to claim 3, wherein the eccentric portion (29) includes a first eccentric portion (27) and a second eccentric portion (28) arranged axially spaced from the first eccentric portion (27), the piston (38) includes a first piston (45) sliding against the outer circumferential surface of the first eccentric portion (27) and a second piston (55) sliding against the outer circumferential surface of the second eccentric portion (28), the first oil supply passage (60) communicates with the outer circumferential surface of the first eccentric portion (27), and the second oil supply passage (70) communicates with the outer circumferential surface of the second eccentric portion (28).

7. The rotary compressor according to any one of claims 1 to 6, wherein the length of the first axial passage (61) and the length of the second axial passage (71) are different from each other.

8. The rotary compressor according to claim 3, wherein the first oil supply passage (60) communicates with the upper bearing surface (26a) of the main shaft portion (26), the second oil supply passage (70) communicates with the lower bearing surface (26b) of the main shaft portion (26), and the length of the first axial passage (61) is longer than the length of the second axial passage (71).

9. A refrigeration system comprising: a rotary compressor (10) according to any one of claims 1 to 8; and a refrigerant circuit (1a) through which a refrigerant compressed by the rotary compressor (10) flows.

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