Rotary compressor

Abstract

The rotary compressor (1) includes a drive shaft (31), a compression mechanism (30) for a refrigerant, and a casing (10). The compression mechanism (30) has a bearing (41) fixed to the casing (10) by a fixture member (44). The fixture member (44) has a first plate portion (44a) above the bearing (41), and the fixture member (44) and the compression mechanism (30) have a flow path for a fluid. The flow path includes a fluid inlet (44d) including a first plate portion (44a), a wall surface (41k) below the fluid inlet (44d), a first space (P1) between the fluid inlet (44d) and the wall surface (41k), a second space (P2) which is positioned below the fixture member (44) and shifted from the first space (P1) in a radial direction and / or a circumferential direction and through which the fluid that has collided with the wall surface (41k) flows, and a fluid outlet (41j) below the second space (P2).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a rotary compressor. 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 swings with the eccentric rotation of the roller, and a so-called hinge vane type 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] The compressor of Patent Document 1 includes a casing having a cylindrical shell plate, and a compression mechanism housed inside the casing. A mounting plate is fixed to the inner peripheral surface of the shell plate by welding. The compression mechanism is fastened to the mounting plate with a bolt. The mounting plate has an oil return passage for returning the lubricant to an oil reservoir at the bottom of the casing.CITATION LISTPATENT DOCUMENT

[0003] Patent Document 1: Japanese Unexamined Patent Publication No. 2022-11909SUMMARY OF THE INVENTIONTECHNICAL PROBLEM

[0004] In the above configuration, the refrigerant flows in the casing from its upper portion to its lower portion through the oil return passage of the mounting plate. The flow of the refrigerant disturbs the oil surface at the bottom of the casing, and the lubricant is atomized into a mist and carried upward. The lubricant in mist form tends to rise to the electric motor together with the discharged refrigerant gas. As a result, the lubricant flows out from the compressor, which causes a failure of the compressor.

[0005] An object of the present disclosure is to reduce lubricant leakage from the compressor.SOLUTION TO THE PROBLEM

[0006] A first aspect of the present disclosure is directed to a rotary compressor (1) including: a drive shaft (31) extending in a top-to-bottom direction; a compression mechanism (30) connected to the drive shaft (31) and configured to compress a refrigerant; and a casing (10) housing the drive shaft (31) and the compression mechanism (30) and having a cylindrical barrel (11). The compression mechanism (30) includes: a bearing (41) that pivotally supports the drive shaft (31) and is fixed to the casing (10) via a fixture member (44); a cylinder (34a, 34b) having a cylinder chamber and disposed below the bearing (41); and a roller (36a, 36b) configured to rotate eccentrically in the cylinder chamber by driving the drive shaft (31). The fixture member (44) includes a first plate portion (44a) positioned above the bearing (41). A flow path through which a fluid passes is formed in the fixture member (44) and the compression mechanism (30). The flow path includes: a fluid inlet (44d) provided in the first plate portion (44a); a wall surface (41k) which is positioned below the fluid inlet (44d) and against which the fluid passing through the fluid inlet (44d) collides; a first space (P1) between the fluid inlet (44d) and the wall surface (41k); a second space (P2) which is positioned below the fixture member (44) and shifted from the first space (P1) in at least a radial direction or a circumferential direction, and through which the fluid that has collided with the wall surface (41k) flows; and a fluid outlet (41j) provided below the second space (P2).

[0007] In the first aspect, since the wall surface (41k) with which the fluid collides is provided in the flow path, the liquid surface of the lubricant stored in the lower portion of the casing is less likely to be disturbed.

[0008] A second aspect of the present disclosure is an embodiment of the first aspect. In the second aspect, a part of the second space (P2) is a space sandwiched between a lower surface of the fixture member (44) and an upper surface of the bearing (41).

[0009] In the second aspect, the fluid can pass through the space sandwiched between the lower surface of the fixture member (44) and the upper surface of the bearing (41).

[0010] A third aspect of the present disclosure is an embodiment of the first or second aspect. In the third aspect, the bearing (41) has a through hole extending in the top-to-bottom direction and communicating with the fluid outlet (41j).

[0011] In the third aspect, the through hole may be used as a part of the flow path for a fluid.

[0012] A fourth aspect of the present disclosure is an embodiment of any one of the first to third aspects. In the fourth aspect, when viewed in the top-to-bottom direction, an area of a portion of the wall surface (41k) overlapping with the fluid inlet (44d) is equal to or larger than 50% of an area of the fluid inlet (44d).

[0013] In the fourth aspect, the effect of the fluid colliding with the wall surface (41k) is likely to be exhibited.

[0014] A fifth aspect of the present disclosure is an embodiment of any one of the first to third aspects. In the fifth aspect, when viewed in the top-to-bottom direction, an area of a portion of the wall surface (41k) overlapping with the fluid inlet (44d) is equal to an area of the fluid inlet (44d).

[0015] In the fifth aspect, the effect of the fluid colliding with the wall surface (41k) is further likely to be exhibited.

[0016] A sixth aspect of the present disclosure is an embodiment of any one of the first to fifth aspects. In the sixth aspect, the wall surface (41k) is a flat surface, and an angle of the wall surface (41k) with respect to the upper surface of the fixture member (44) is 0° or more and 45° or less.

[0017] In the sixth aspect, the effect of the fluid colliding with the wall surface (41k) is realized, and a good fluid flow is realized.

[0018] A seventh aspect of the present disclosure is an embodiment of any one of the first to fifth aspects. In the seventh aspect, the wall surface (41k) is a curved surface.

[0019] Also in the seventh aspect, the effect of the fluid colliding with the wall surface (41k) is realized.

[0020] An eighth aspect of the present disclosure is an embodiment of any one of the first to seventh aspects. In the eighth aspect, the wall surface (41k) is formed of a part of the bearing (41).

[0021] The wall surface (41k) may be configured as in the eighth aspect.

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

[0023] When carbon dioxide is used as the refrigerant, the oil carryover tends to increase, whereby a remarkable effect is realized in the ninth aspect.

[0024] A tenth aspect of the present disclosure is an embodiment of any one of the first to ninth aspects. In the tenth aspect, a maximum number of revolutions exceeds 100 revolutions per second.

[0025] When the number of revolutions is high, the oil carryover tends to increase, whereby a remarkable effect is realized in the tenth aspect.

[0026] An eleventh aspect of the present disclosure is directed to a refrigeration apparatus (100) including the rotary compressor (1) of any one of the first to tenth aspects.

[0027] The eleventh aspect is useful for the rotary compressor including the refrigeration apparatus (100).BRIEF DESCRIPTION OF THE DRAWINGS

[0028] [FIG. 1] FIG. 1 is a schematic diagram illustrating a configuration of a refrigeration apparatus including a rotary compressor of the present disclosure. [FIG. 2] FIG. 2 is a schematic sectional view of a rotary compressor according to an embodiment of the present disclosure. [FIG. 3] FIG. 3 is a plan view of a piston in the rotary compressor of the present disclosure. [FIG. 4] FIG. 4 is a schematic plan view of a mounting plate (fixture member) in the present disclosure. [FIG. 5] FIG. 5 is a perspective view of the mounting plate illustrated in FIG. 4. [FIG. 6] FIG. 6 shows operation of the rotary compressor. [FIG. 7] FIG. 7 is a sectional view taken along line A-A in FIG. 4, which is a schematic sectional view of a flow path through which a fluid containing a lubricant and a refrigerant passes in the present disclosure. [FIG. 8] FIG. 8 is a diagram schematically illustrating a cross section of a flow path of a comparative example. [FIG. 9] FIG. 9 is a sectional view of another example of the flow path in the present disclosure. [FIG. 10] FIG. 10 is a sectional view of another example of the flow path in the present disclosure. [FIG. 11] FIG. 11 is a sectional view of another example of the flow path in the present disclosure. [FIG. 12] FIG. 12 is a sectional view of another example of the flow path in the present disclosure. [FIG. 13] FIG. 13 is a sectional view of another example of the flow path in the present disclosure. [FIG. 14] FIG. 14 is a sectional view of another example of the flow path in the present disclosure. [FIG. 15] FIG. 15 is a sectional view of another example of the flow path in the present disclosure. [FIG. 16] FIG. 16 is a plan view of another configuration of the flow path in the present disclosure. DESCRIPTION OF EMBODIMENTS

[0029] Embodiments of the present invention will now be described in detail with reference to the drawings. Note that the following description of embodiments is merely an example in nature, and is not intended to limit the scope, applications, or use of the present invention.(Refrigeration Apparatus)

[0030] As illustrated in FIG. 1, a rotary compressor (1) of this embodiment is applied to a refrigeration apparatus (100). The refrigeration apparatus (100) is an air conditioner for conditioning air in an indoor space, for example. The refrigeration apparatus (100) has an outdoor unit (7) disposed outdoors and an indoor unit (8) disposed indoors. The outdoor unit (7) includes a rotary compressor (1), a four-way switching valve (3), an outdoor heat exchanger (4), and an expansion valve (5). The indoor unit (8) includes an indoor heat exchanger (6).

[0031] The refrigeration apparatus (100) includes a refrigerant circuit (9). The rotary compressor (1), an accumulator (2), the four-way switching valve (3), the outdoor heat exchanger (4), the expansion valve (5), and the indoor heat exchanger (6) are connected to the refrigerant circuit (9). In the refrigerant circuit (9), refrigerant circulates to perform a refrigeration cycle.(Rotary Compressor)

[0032] The compressor (1) of the present embodiment is a rotary compressor. The compressor (1) is connected to a refrigerant circuit (9) that circulates a refrigerant to perform a refrigeration cycle, thereby compressing the refrigerant. As illustrated in FIG. 2, the compressor (1) includes a casing (10), an electric motor (20), and a compression mechanism (30). The electric motor (20) and the compression mechanism (30) are housed in the casing (10). The compressor (1) is configured as a so-called high-pressure dome-shaped compressor where the refrigerant compressed in the compression mechanism (30) is discharged into the internal space (S) of the casing (10) and the pressure inside the internal space (S) becomes high.

[0033] The casing (10) includes a cylindrical barrel (11) extending in the top-to-bottom direction, an upper end plate (12) closing an upper end of the barrel (11), a lower end plate (13) closing a lower end of the barrel (11). The upper end plate (12) and the lower end plate are formed to be relatively thick. The barrel (11) has, at its lower portion, a suction pipe (14). The upper end plate (12) is provided with a discharge pipe (15) and a terminal (16) for supplying electric power to the electric motor (20). The casing (10) has, at its bottom, an oil reservoir (17). The oil reservoir (17) stores lubricant for lubricating sliding portions inside the compression mechanism (30).

[0034] The electric motor (20) is arranged in an upper portion of the barrel (11) in the casing (10). With the electric motor (20) arranged, the internal space (S) is divided into a first internal space (S1) below the electric motor (20) and a second internal space (S2) above the electric motor (20). The electric motor (20) has a tubular stator (21) fixed along the inner peripheral surface of the barrel (11), and a rotor (22) disposed inside the stator (21). The outer peripheral surface of the stator (21) has a plurality of core cuts (23). The core cuts (23) provide communication between the first internal space (S1) and the second internal space (S2). Specifically, the core cuts (23) are formed to be arranged in the circumferential direction of the stator (21). The core cuts (23) extend in the axial direction of the stator (21). With such a configuration, a refrigerant gas discharged from the first internal space (S1) flows through the core cuts (23) into the second internal space (S2).

[0035] The compression mechanism (30) is disposed below the electric motor (20) in the casing (10). The compression mechanism (30) is fastened to a mounting plate (44) to be described later with a bolt (73). The compression mechanism (30) includes a drive shaft (31), a first cylinder (34a), a second cylinder (34b), a front head (41), a middle plate (42), a rear head (43), a first piston (35a), and a second piston (35b). The front head (41), the first cylinder (34a), and the middle plate (42) constitute a first cylinder chamber. The middle plate (42), the second cylinder (34b), and the rear head (43) constitute a second cylinder chamber.

[0036] The drive shaft (31) is disposed to extend in the top-to-bottom direction in the casing (10). An upper portion of the drive shaft (31) is connected to a rotor (22) of the electric motor (20). A lower portion of the drive shaft (31) includes, in order from top to bottom, an upper shaft portion (31a), a first eccentric portion (32a), an intermediate shaft portion (31b), a second eccentric portion (32b), and a lower shaft portion (31c). The first eccentric portion (32a) and the second eccentric portion (32b) are eccentric with the axis of the drive shaft (31) such that their rotational phases differ by 180°. The first eccentric portion (32a) and the second eccentric portion (32b) are provided to have larger diameters than the upper shaft portion (31a), the intermediate shaft portion (31b), and the lower shaft portion (31c).

[0037] An oil pump (61) is fixed to the lower end of the drive shaft (31). The oil pump (61) sucks lubricant in the oil reservoir (17). An oil supply passage (62) is provided inside the drive shaft (31). The oil supply passage (62) is a passage through which the lubricant sucked by the oil pump (61) flows. The oil supply passage (62) includes a main oil supply path (62a) and a plurality of oil supply openings (62b). The main oil supply path (62a) extends in the top-to-bottom direction, and the lower end of the main oil supply path (62a) communicates with the oil pump (61). The oil supply openings (62b) extend radially outward at an intermediate point of the main oil supply path (62a), and the outer peripheral ends of the oil supply openings (62b) are open to the side surface of the drive shaft (31). With such a configuration, the lubricant in the oil reservoir (17) is supplied to sliding portions of the drive shaft (31) and the pistons (35a, 35b).

[0038] FIG. 3 is a plan view of the piston. As illustrated in FIG. 3, the first cylinder (34a) and the second cylinder (34b) are each formed into a substantially cylindrical shape. The shaft of the first cylinder (34a) and the shaft of the second cylinder (34b) extend in the top-to-bottom direction. The second cylinder (34b) is disposed below the first cylinder (34a). The first eccentric portion (32a) of the drive shaft (31) is inserted into the first cylinder (34a), and the second eccentric portion (32b) of the drive shaft (31) is inserted into the second cylinder (34b).

[0039] The first piston (35a) is housed in the first cylinder (34a). The first piston (35a) is configured to slide to both an upper front head (41) and a lower middle plate (42). The first piston (35a) has a first roller (36a) and a first vane (37a).

[0040] The first roller (36a) is formed in an annular shape. Specifically, the first roller (36a) is formed in a slightly-thick cylindrical shape. The first eccentric portion (32a) of the drive shaft (31) is slidably inserted into the first roller (36a). The first roller (36a) is configured to revolve along the inner peripheral surface of the first cylinder (34a) when the drive shaft (31) rotates. A first compression chamber (50a) is provided between the first roller (36a) and the first cylinder (34a).

[0041] The first vane (37a) is formed integrally with the first roller (36a). The first vane (37a) protrudes radially outward from the outer peripheral surface of the first roller (36a). The first vane (37a) is sandwiched between a pair of first swing bushings (54a, 54b) provided in a first bushing groove (53a) extending radially outward from the inner peripheral surface of the first cylinder (34a). The first vane (37a) is configured to restrict rotation of the first roller (36a) when the first roller (36a) revolves. The first vane (37a) partitions the first compression chamber (50a) into a first low-pressure chamber (51a) and a first high-pressure chamber (52a).

[0042] The first cylinder (34a) has a first suction port (55a) penetrating in the radial direction. The inner peripheral end of the first suction port (55a) communicates with the first low-pressure chamber (51a), and the outer peripheral end of the first suction port (55a) is connected to a first suction pipe (14a).

[0043] The second piston (35b) is housed in the second cylinder (34b), and is configured to slide to both the upper middle plate (42) and the lower rear head (43). As illustrated in FIG. 2, the second piston (35b) has the same configuration as the first piston (35a), and the detailed description thereof will thus be omitted.(Mounting Plate)

[0044] FIG. 4 is a schematic plan view of a mounting plate (44), which corresponds to a view seen from above in FIG. 2. FIG. 2 shows a barrel (11) in addition to the mounting plate (44) and a front head (41). However, for the sake of clarity, elements related to the following description are mainly illustrated in the drawings, and some of the elements of the front head (41) are not shown. FIG. 5 is a perspective view of the mounting plate (44).

[0045] As illustrated in FIGS. 2 and 4, the mounting plate (44) is a fixture member (44) of the present disclosure. The mounting plate (44) is fixed to the barrel (11). The mounting plate (44) is disposed to cover the front head (41) from above.

[0046] The mounting plate (44) includes: a cylindrical peripheral portion (44b) fixed to the inner surface of the barrel (11) by welding or the like; and a plate-shaped annular portion (44a) continuously formed at one end of the peripheral portion (44b) and having a circular central opening (44e) at its center. In the annular portion (44a), a plurality of (six in this example) through holes (44c) for bolting and a plurality of (six in this example) fluid inlets (44d) are alternately arranged in the circumferential direction at substantially equal intervals.

[0047] The through holes (44c) are each a hole through which a bolt (73) fastening the mounting plate (44) and the front head (41) is inserted. The through holes (44c) are formed at the respective positions corresponding to fastening holes (41h) in a first disc portion (41b). Six bolts (73) are inserted through the mounting plate (44) from above to fix the mounting plate (44) to the front head (41).

[0048] The front head (41) is inserted to close the central opening (44e). With regard to this, as illustrated in FIG. 2, the front head (41) has a first disc portion (41b) and a first boss (41c) extending upward from the center of the first disc portion (41b). An upper bearing (41a) is formed in the front head (41). The upper bearing (41a) rotatably supports the upper shaft portion (31a) of the drive shaft (31).

[0049] The first disc portion (41b) has a protruding longitudinal cross section. To be specific, the first disc portion (41b) has a step portion (41d) formed around the first boss (41c). The lower surface of the first disc portion (41b) is flat. The lower surface of the first disc portion (41b) closes the upper end of the first cylinder (34a).

[0050] The first disc portion (41b) is circular, and its outer periphery faces the inner peripheral surface of the peripheral portion (44b) of the mounting plate (44). Around the outer periphery of the first disc portion (41b), a plurality of (six in this example) fastening holes (41h) and a plurality of fluid outlets (41j) are alternately arranged at substantially equal intervals in the circumferential direction. A first discharge valve (411) (see FIG. 2, not shown in FIG. 4) is provided near the first boss in the first disc portion (41b). The discharge valve is a valve provided at a discharge port (not shown) allowing the first high-pressure chamber (52a) and a first muffler chamber (R1) to be described later to communicate with each other. The first discharge valve is configured to open when the pressure of the refrigerant in the first high-pressure chamber (52a) reaches a predetermined value or higher.

[0051] The front head (41) is inserted such that the outer peripheral surface of the step portion (41d) of the front head (41) faces the inner surface of the central opening (44e) in the mounting plate (44) (FIG. 2). The lower surface of the annular portion (44a) is flat, and contacts the upper surface of the first disc portion (41b) of the front head (41).

[0052] A front muffler (71) is fixed to the front head (41). The front muffler (71) is fixed to the upper surface of the front head (41) so as to cover the first discharge valve (41i). The first boss (41c) is inserted into the front muffler (71). The first muffler chamber (R1) is provided between the front muffler (71) and the front head (41). The first muffler chamber (R1) communicates with the first high-pressure chamber (52a) and a second high-pressure chamber (52b). The front muffler (71) has a communication hole (75) allowing the first muffler chamber (R1) and the first internal space (S1) to communicate with each other.

[0053] The middle plate (42) is fixed to the lower end of the first cylinder (34a) and the upper end of the second cylinder (34b) to close the lower end of the first cylinder (34a) and the upper end of the second cylinder (34b). The intermediate shaft portion (31b) of the drive shaft (31) is inserted into the middle plate (42).

[0054] As illustrated in FIG. 2, the rear head (43) includes a second disc portion (43b), a second boss (43c) extending downward from the center of the second disc portion (43b), and a cylindrical portion (43e) extending downward from the outer edge of the second disc portion (43b). The upper surface of the second disc portion (43b) of the rear head (43) closes the lower end of the second cylinder (34b). A lower bearing (43a) is formed in the rear head (43). The lower bearing (43a) rotatably supports the lower shaft portion (31c) of the drive shaft (31). The second disc portion (43b) is provided with a second discharge valve (43d). The second discharge valve (43d) is a valve provided at a discharge port (not shown) allowing the second high-pressure chamber (52b) and a second muffler chamber (R2) to be described later to communicate with each other. The second discharge valve (43d) is configured to open when the pressure of the refrigerant in the second high-pressure chamber (52b) reaches a predetermined value or higher.

[0055] A rear muffler (72) is fixed to the rear head (43). The rear muffler (72) is formed in a flat plate. The rear muffler (72) is provided to cover the second discharge valve (43d). Specifically, the rear muffler (72) is connected to the lower end of the second boss (43c) and the lower end of the cylindrical portion (43e). With such a configuration, the second muffler chamber (R2) is provided between the rear head (43) and the rear muffler (72). The second muffler chamber (R2) communicates with the first muffler chamber (R1) via a communication passage (not shown).(Operation)

[0056] As shown in FIG. 6, in the rotary compressor (1), when the electric motor (20) is activated to rotate the rotor (22), the drive shaft (31) rotates, and two eccentric portions (32a, 32b) rotate eccentrically while maintaining a rotational phase difference of 180°. With the eccentric rotation of the eccentric portions (32a, 32b), two pistons (35a, 35b) revolve along the inner peripheral surfaces of cylinders (34a, 34b) while restricting the rotation of two pistons (35a, 35b).

[0057] A suction phase of sucking the refrigerant into the first compression chamber (50a) will now be described below. As illustrated in FIG. 6, when the drive shaft (31) slightly rotates from the state (the state of (A) in FIG. 6) of the rotational angle of 0°, a contact portion between the first piston (35a) and the first cylinder (34a) passes by the inner peripheral end of the first suction port (55a). At this time, suction of the refrigerant into the first low-pressure chamber (51a) is started.

[0058] The refrigerant is sucked from the first suction pipe (14a) through the first suction port (55a). With the increase in the rotational angle of the drive shaft (31), the capacity of the first low-pressure chamber (51a) increases, thereby increasing the amount of the refrigerant sucked into the first low-pressure chamber (51a) (the states shown in (B) to (H) of FIG. 6). This suction phase of sucking the refrigerant continues until the rotational angle of the drive shaft (31) reaches 360°, and then shifts to a discharge phase. The suction phase for the refrigerant in the second compression chamber (50b) is the same as the suction phase in the first compression chamber (50a).

[0059] Next, the discharge phase of compressing the refrigerant in the first compression chamber (50a) and discharging the compressed refrigerant will be described below. When the drive shaft (31) slightly rotates from the state (the state of (A) in FIG. 6) of the rotational angle of 0°, a contact portion between the first piston (35a) and the first cylinder (34a) again passes by the inner peripheral end of the first suction port (55a). At this time, confinement of the refrigerant in the first low-pressure chamber (51a) is completed.

[0060] The first low-pressure chamber (51a) which has communicated with the first suction port (55a) serves as the first high-pressure chamber (52a) communicating with only the discharge port (not shown). From this state, the compression of the refrigerant in the first high-pressure chamber (52a) is started. With the increase in the rotational angle of the drive shaft (31), the capacity of the first high-pressure chamber (52a) decreases, and the pressure in the first high-pressure chamber (52a) increases. When the pressure in the first high-pressure chamber (52a) reaches a predetermined pressure or more, the first discharge valve (41i) is open. At this time, the refrigerant in the first high-pressure chamber (52a) is discharged into the first muffler chamber (R1) via the discharge port. Also in the second compression chamber (50b), the same discharge phase as in the first compression chamber (50a) is conducted. The refrigerant in the second high-pressure chamber (52b) is discharged into the second muffler chamber (R2) via the discharge port. The refrigerant discharged into the second muffler chamber (R2) passes through a communication passage (not shown), and merges with the refrigerant in the first muffler chamber (R1).

[0061] The refrigerant in the first muffler chamber (R1) is discharged into the first internal space (S1) via the communication hole (75) in the front muffler (71). The refrigerant passes through the core cuts (23) and a gap between the stator (21) and the rotor (22), and flows into the second internal space (S2). The gas refrigerant that has flowed into the second internal space (S2) is discharged outside of the compressor (1) via the discharge pipe (15). The discharge phase for the refrigerant continues until the rotational angle of the drive shaft (31) reaches 360°, and then shifts to the suction phase.

[0062] As described above, in the rotary compressor (1), in each compression chamber (50a, 50b), the suction phase and the discharge phase are alternately performed, whereby the operation of compressing the refrigerant is continuously performed.(Flow Path for Lubricant)

[0063] As described above, the refrigerant that has been compressed in the compression mechanism (30a, 30b) is discharged from the first muffler chamber (R1) to the internal space (S1). Thus, the pressure of the lubricant stored in the oil reservoir (17) of the casing (10) is substantially equal to the pressure of the high-pressure refrigerant discharged from the compression mechanism (30) to the internal space (S1) of the casing (10).

[0064] The high-pressure lubricant in the oil reservoir (17) passes through the oil supply passage (62) of the drive shaft (31) and is supplied to the compression mechanism (30). The high-pressure lubricant that has been supplied to the compression mechanism (30) flows into the gap between the upper shaft portion (31a) and the drive shaft (31), the gap between the lower shaft portion (31c) and the drive shaft (31), the gap between the first eccentric portion (32a) and the first piston (35a), and the gap between the second eccentric portion (32b) and the second piston (35b). The high-pressure lubricant that has been supplied to the compression mechanism (30) also flows into the gap between the upper end surface of the first piston (35a) and the front head (41) and the gap between the lower end surface of the second piston (35b) and the rear head (43).

[0065] After that, part of the lubricant that has been supplied to the compression mechanism (30) is mixed with the refrigerant gas that has been discharged into the first internal space (S1), and is then carried upward into the first internal space (S1). Part of the lubricant that has been carried upward is further carried upward into the second internal space (S2) above the electric motor (20). Thus, part of the lubricant tends to flow out of the compressor through the discharge pipe (15) together with the refrigerant gas, while the other part of the lubricant passes through the core cuts (23) in the outer peripheral surface of the stator (21) and falls into the first internal space (S1). Such lubricant and the lubricant that has not been carried upward into the second internal space (S2) fall into the oil reservoir (17).

[0066] At this time, the fluid containing the lubricant and the refrigerant gas passes through a flow path formed between the fluid inlet (44d) provided in the annular portion (44a) of the mounting plate (44) and the fluid outlet (41j) provided in the front head (41).

[0067] With regard to this, the schematic cross section taken along line A-A in FIG. 4 is shown in FIG. 7. As mentioned above, the peripheral portion (44b) of the mounting plate (44) is fixed to the inner periphery of the barrel (11) of the casing (10), and the first disc portion (41b) of the front head (41) is fixed to the mounting plate (44). As illustrated in FIGS. 4 and 7 and the like, the annular portion (44a) has fluid inlets (44d) as opening surfaces, and first spaces (P1) are provided below the opening surfaces. Second spaces (P2) are provided in the first disc portion (41b), and the opening surfaces below the second spaces (P2) are fluid outlets (41j).

[0068] When viewed in the top-to-bottom direction, the fluid inlets (44d) are displaced from the fluid outlets (41j) and do not overlap each other. However, the annular portion (44a) is thinner above the fluid outlets (41j), and the first spaces (P1) and second spaces (P2) are connected to each other. Accordingly, flow paths through which a fluid passes from the annular portion (44a) to the first disc portion (41b) are formed. When viewed in the top-to-bottom direction, the upper surface of the first disc portion (41b) protrudes into the fluid inlets (44d), and the protrusions serve as wall surfaces (41k) against which the passing fluid collides.

[0069] With such a configuration of the flow paths, the lubricant in the oil reservoir (17) can be substantially prevented from being atomized into a mist by the fluid flowing from the first internal space (S1) into the oil reservoir (17), which would otherwise causes oil carryover.

[0070] FIG. 8 shows a comparative example in which the fluid inlet (44d) and the fluid outlet (41j) coincide with each other when viewed in the top-to-bottom direction so that there is no wall surface against which the fluid collides. In such a case, the fluid passes through the flow path formed by the first space (P1) and the second space (P2) without any obstruction, and is directed onto the liquid surface of the lubricant in the oil reservoir (17). As a result, the liquid surface of the lubricant is disturbed, and the lubricant is atomized into a mist, which causes the lubricant to be carried upward into the first internal space (S1) together with the refrigerant.

[0071] In contrast, in the example of FIG. 7, the wall surface (41k) that becomes an obstacle is present in the flow path, and the fluid passes through the flow path while colliding with the wall surface (41k). As a result, the fluid is not directly directed to the liquid surface, but flows into the oil reservoir (17) with its momentum reduced. Therefore, the disturbance of the liquid surface due to the fluid is suppressed, and the lubricant is substantially prevented from being carried upward.(Other Shape of Flow Path)

[0072] The shape of the flow path is not limited to the example of FIG. 7. FIG. 9 shows an example in which the wall surface (41k) is inclined with respect to the upper surface of the annular portion (44a).

[0073] That is, in the example of FIG. 7, the wall surface (41k) is a flat surface and is configured to be parallel to the upper surface of the annular portion (44a). In contrast, in the example of FIG. 9, the wall surface (41k) is configured as a flat surface that forms an angle of θ with respect to the upper surface of the annular portion (44a). Also in this case, the fluid passes through the flow path while colliding with the wall surface (41k), and the liquid surface in the oil reservoir (17) is substantially prevented from being disturbed. In addition, the fluid easily flows due to the inclined surface. The angle θ is preferably 0° or more and 45° or less. In order for the wall surface (41k) to exhibit the function as an obstacle in the flow path, the angle θ is preferably in such a range.

[0074] As illustrated in FIG. 10, the wall surface (41k) may be a curved surface. For example, in order to control the flow of the fluid, the curved surface may be effective. However, since the wall surface (41k) functions as an obstacle that causes the fluid to collide with it, it must be designed with the effect of reducing oil carryover. In FIG. 10, the entire wall surface (41k) is a curved surface, but the wall surface (41k) may be partially curved, such as in a shape in which a corner portion is rounded in FIG. 7.

[0075] Further, as illustrated in FIG. 11, a portion of the annular portion (44a) above the fluid outlet (41j) which has a reduced plate thickness may not be provided, and instead, a recess may be provided in the first disc portion (41b) below the fluid inlet (44d). Thus, a flow path connecting the first space (P1) and the second space (P2) displaced from each other when viewed in the top-to-bottom direction is formed.

[0076] Also in this case, the effect of preventing the lubricant from being carried upward is also exhibited as in the example of FIG. 7. Further, when the front head (41) including the first disc portion (41b) is manufactured as a cast, such a shape can be easily realized, and therefore it may be preferable to form the annular portion (44a) in this manner rather than making it of a more complex shape. Also in the case of FIGS. 9 and 10, it is possible to employ a configuration in which a portion of the annular portion (44a) above the fluid outlet (41j) which has a reduced plate thickness is not provided.

[0077] In the example of FIG. 7, when viewed in the top-to-bottom direction, the fluid inlet (44d) and the fluid outlet (41j) are displaced from each other, but are disposed adjacent to each other. The displacement may be larger. Such a configuration is shown in FIG. 12. In the case of FIG. 12, the fluid inlet (44d) and the fluid outlet (41j) are not adjacent to each other when viewed in the top-to-bottom direction, and instead communicate with each other through a gap between a portion of the annular portion (44a) which has a reduced thickness and the first disc portion (41b) (as shown in FIG. 11, this communication may be provided by forming a recess on the side of the first disc portion (41b) instead of the annular portion (44a)). Such a shape may be employed for control of the state of the fluid flowing into the oil reservoir (17) and for convenience of the arrangement of the fluid inlet (44d) and the fluid outlet (41j).

[0078] In the above description, the first disc portion (41b) of the front head (41) constitutes the wall surface (41k), but the annular portion (44a), which is a part of the mounting plate (44), may constitute the wall surface (41k). An example of this is shown in FIG. 13. In FIG. 13, a portion of the annular portion (44a) extending below the fluid inlet (44d) is provided, and thus, the upper surface thereof is used as the wall surface (41k).

[0079] The above description shows a configuration in which the fluid inlet (44d) and the first space (P1) are located on the outer peripheral side of the compressor (1) (near the barrel (11), the left side in FIG. 7 and the like), and the fluid outlet (41j) and the second space (P2) are arranged inside. When the fluid flows from the second internal space (S2) above the electric motor (20) into the first internal space (S1) below the electric motor (20), the fluid passes through the core cuts (23). In order to move the fluid into the oil reservoir (17), the fluid inlet (44d), which serves as an inlet of the flow path, is preferably located on the outer peripheral side.

[0080] However, as illustrated in FIG. 14, a configuration in which the fluid inlet (44d) is disposed inward of the fluid outlet (41j) may also be employed.

[0081] When viewed in the top-to-bottom direction, the fluid inlet (44d) and the fluid outlet (41j) do not overlap with each other. In such a case, when viewed in the top-to-bottom direction, an area of a portion of the wall surface (41k) overlapping with the fluid inlet (44d) is equal to an area of the fluid inlet (44d). This is a desirable configuration in view of causing the fluid passing through the flow path to collide with the wall surface (41k), but is not essential.

[0082] That is, as illustrated in FIG. 15, when viewed in the top-to-bottom direction, the fluid inlet (44d) and the fluid outlet (41j) may be displaced from each other so as to partially overlap with each other, and the wall surface (41k) may overlap only with a portion of the fluid inlet (44d). Also in such a case, the fluid is caused to collide with the wall surface (41k), so that the effect of reducing the turbulence of the liquid surface in the oil reservoir (17) is exhibited. The area of the wall surface (41k) overlapping with the fluid inlet (44d) is desirably large, and is desirably, for example, 50% or more.

[0083] In the above, the fluid inlet (44d) and the fluid outlet (41j) are displaced from each other in the radial direction when viewed in the top-to-bottom direction, but may be displaced from each other in the circumferential direction as illustrated in FIG. 16. Further, the fluid inlet (44d) and the fluid outlet (41j) may be displaced from each other in both the circumferential direction and the radial direction. The configurations of the first space (P1) and the second space (P2) in this case may be the same as those shown in FIGS. 7 and 9 to 15.

[0084] Here, the second space (P2) is preferably displaced from the first space (P1) in the rotational direction of the drive shaft (31). It is assumed that the fluid containing a lubricant and a refrigerant flows along the rotational direction of the drive shaft (31). Therefore, when the first space (P1) and the second space (P2) are arranged in this flow direction, the fluid can collide with the wall surface (41k) while maintaining the speed of the fluid, and the effect of preventing the lubricant from being carried upward is likely to be exhibited. However, this does not exclude the reverse arrangement.

[0085] In the above, the example in which the first disc portion (41b) of the front head (41) or the annular portion (44a) of the mounting plate (44) forms the wall surface (41k) has been described. The wall surface (41k) may be formed of other members different from these members. The other members may be components other than the first disc portion (41b) in the compression mechanism (30), such as the first cylinder (34a), or may be an oil separation plate or the like different from the compression mechanism (30).<<Other Embodiments>>

[0086] The compressor (1) of the present disclosure may use carbon dioxide (CO 2 ) as a refrigerant. When carbon dioxide is used as the refrigerant, the amount of lubricant carried upward increases due to properties of carbon dioxide such as its miscibility with the lubricant. Thus, the configuration of the present disclosure, which substantially prevents the lubricant from being carried upward, is particularly useful.

[0087] The compressor (1) of the present disclosure may be a multi-cylinder compressor. Since the amount of lubricant carried upward increases as the capacity of the compressor increases, the configuration of the present disclosure is particularly useful in the multi-cylinder compressor having a large capacity.

[0088] The compressor (1) of the present disclosure may be a rotary compressor having a maximum number of revolutions of more than 100 revolutions per second. In the compressor, the higher the number of revolutions, the larger the oil carryover, and the more likely the oil level is to drop. In particular, in the case of a compressor using carbon dioxide as a refrigerant, the oil carryover particularly increases when the number of revolutions is higher than 100 revolutions per second, and the oil level tends to drop. Thus, the configuration of the present disclosure is particularly useful in the compressor (1) having a maximum number of revolutions of larger than 100 revolutions per second.

[0089] Although a so-called swing-type compressor in which a vane formed integrally with a roller swings with the eccentric rotation of the roller has been described as an example, the present disclosure can also be applied to a so-called rolling piston compressor in which a roller eccentrically rotates while a vane separate from the roller abuts on the roller, and a so-called hinge vane type 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.

[0090] While the embodiments and the variations thereof have been described above, it will be understood that various changes in form and details may be made without departing from the spirit and scope of the claims. The elements according to the embodiments, the variations thereof, and the other embodiments may be combined and replaced with each other.INDUSTRIAL APPLICABILITY

[0091] As described above, the present disclosure is useful for a rotary compressor.DESCRIPTION OF REFERENCE CHARACTERS

[0092] 1Rotary Compressor P1First Space P2Second Space 10Casing 11Barrel 30Compression Mechanism 31Drive Shaft 34a, 34bFirst Cylinder 36a, 36bFirst Roller 41Front Head (Bearing) 41jFluid Outlet 41kWall Surface 44Fixture Member (Mounting Plate) 44aAnnular Portion (First Plate Portion) 44dFluid Inlet 100Refrigeration Apparatus

Claims

1. A rotary compressor (1), comprising: a drive shaft (31) extending in a top-to-bottom direction; a compression mechanism (30) connected to the drive shaft (31) and configured to compress a refrigerant; and a casing (10) housing the drive shaft (31) and the compression mechanism (30) and having a cylindrical barrel (11), wherein the compression mechanism (30) includes: a bearing (41) that pivotally supports the drive shaft (31) and is fixed to the casing (10) via a fixture member (44); a cylinder (34a, 34b) having a cylinder chamber and disposed below the bearing (41); and a roller (36a, 36b) configured to rotate eccentrically in the cylinder chamber by driving the drive shaft (31), the fixture member (44) includes a first plate portion (44a) positioned above the bearing (41), a flow path through which a fluid passes is formed in the fixture member (44) and the compression mechanism (30), and the flow path includes: a fluid inlet (44d) provided in the first plate portion (44a); a wall surface (41k) which is positioned below the fluid inlet (44d) and against which the fluid passing through the fluid inlet (44d) collides; a first space (P1) between the fluid inlet (44d) and the wall surface (41k); a second space (P2) which is positioned below the fixture member (44) and shifted from the first space (P1) in at least a radial direction or a circumferential direction, and through which the fluid that has collided with the wall surface (41k) flows; and a fluid outlet (41j) provided below the second space (P2).

2. The rotary compressor (1) of claim 1, wherein part of the second space (P2) is a space sandwiched between a lower surface of the fixture member (44) and an upper surface of the bearing (41).

3. The rotary compressor (1) of claim 1 or 2, wherein the bearing (41) has a through hole extending in the top-to-bottom direction and communicating with the fluid outlet (41j).

4. The rotary compressor (1) of any one of claims 1 to 3, wherein when viewed in the top-to-bottom direction, an area of a portion of the wall surface (41k) overlapping the fluid inlet (44d) is equal to or larger than 50% of an area of the fluid inlet (44d).

5. The rotary compressor (1) of any one of claims 1 to 3, wherein when viewed in the top-to-bottom direction, an area of a portion of the wall surface (41k) overlapping the fluid inlet (44d) is equal to an area of the fluid inlet (44d).

6. The rotary compressor (1) of any one of claims 1 to 5, wherein the wall surface (41k) is a flat surface, and an angle of the wall surface (41k) with respect to the upper surface of the fixture member (44) is 0° or more and 45° or less.

7. The rotary compressor (1) of any one of claims 1 to 5, wherein the wall surface (41k) is a curved surface.

8. The rotary compressor (1) of any one of claims 1 to 7, wherein the wall surface (41k) is formed of part of the bearing (41).

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

10. The rotary compressor (1) of any one of claims 1 to 9, wherein a maximum number of revolutions exceeds 100 revolutions per second.

11. A refrigeration apparatus (100) comprising the rotary compressor (1) of any one of claims 1 to 10.

Images