Rotary compressor

Abstract

A rotary compressor (1) is provided with a drive shaft (31), a refrigerant compression mechanism (30), and a casing (10). The compression mechanism (30) has a bearing part (41) fixed to the casing (10) by a fixing member (44). The fixing member (44) has a first plate section (44a) above the bearing part (41). The fixing member (44) and the compression mechanism (30) have a fluid flow passage. The flow passage has: a fluid introduction port (44d) provided in the first plate section (44a); a wall surface (41k) below the fluid introduction port (44d); a first space (P1) between the fluid introduction port (44d) and the wall surface (41k); a second space (P2) that is radially and / or circumferentially offset from the first space (P1) and is below the fixing member (44) and through which a fluid that has collided with the wall surface (41k) flows; and a fluid discharge port (41j) below the second space (P2).

Description

Rotary compressor

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

[0002] The compressor described in Patent Document 1 has a casing having a cylindrical body plate and a compression mechanism housed inside the casing. A mounting plate is welded and fixed to the inner peripheral surface of the body plate. The compression mechanism is fastened to this mounting plate with bolts. The mounting plate also has an oil return passage for returning lubricating oil to the oil reservoir at the bottom of the casing.

[0003] Japanese Unexamined Patent Application Publication No. 2022-11909

[0004] In the above configuration, a refrigerant flow occurs in the casing that flows downward from above through the oil return passage of the mounting plate. This refrigerant flow disturbs the oil surface at the bottom of the casing and lifts the lubricating oil in a mist form. The mist-like lubricating oil tends to rise up to the motor together with the discharged refrigerant gas. As a result, lubricating oil flows out of the compressor, causing a failure of the compressor.

[0005] An object of the present disclosure is to suppress the outflow of lubricating oil in the compressor.

[0006] A first aspect of this disclosure is based on a rotary compressor (1) comprising a drive shaft (31) extending in the vertical direction, a compression mechanism (30) connected to the drive shaft (31) for compressing a refrigerant, and a casing (10) housing the drive shaft (31) and the compression mechanism (30) and having a cylindrical body (11). The compression mechanism (30) includes a bearing portion (41) that pivotally supports the drive shaft (31) and is fixed to the casing (10) via a fixing member (44), cylinders (34a, 34b) having a cylinder chamber and positioned below the bearing portion (41), and rollers (36a, 36b) that rotate eccentrically within the cylinder chamber by the drive of the drive shaft (31). The fixing member (44) has a first plate portion (44a) located above the bearing portion (41). A fluid passage is formed in the fixing 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) located below the fluid inlet (44d) and upon which the fluid that has passed through the fluid inlet (44d) collides, a first space (P1) between the fluid inlet (44d) and the wall surface (41k), a second space (P2) located at a position offset from the first space (P1) in at least one direction in the radial and circumferential directions and located below the fixing member (44), through which the fluid flows after colliding with the wall surface (41k), and a fluid outlet (41j) provided below the second space (P2).

[0007] In the first embodiment, since a wall surface (41k) is provided in the flow path against which the fluid collides, the liquid level of the lubricating oil stored in the lower part of the casing is less likely to be disturbed.

[0008] A second aspect of this disclosure is, in the first aspect, a portion of the second space (P2) is the space sandwiched between the lower surface of the fixing member (44) and the upper surface of the bearing portion (41).

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

[0010] A third aspect of the present disclosure is the bearing portion (41) having a through hole that extends vertically and connects to the fluid outlet (41j) in the first or second embodiment.

[0011] In the third embodiment, the through-holes can be used as part of the flow path for the granular material.

[0012] A fourth aspect of this disclosure is that, in any one of the first to third aspects, when viewed in the vertical direction, the area of ​​the wall surface (41k) that overlaps with the fluid inlet (44d) is 50% or more of the area of ​​the fluid inlet (44d).

[0013] In the fourth embodiment, the effect of the fluid colliding with the wall surface (41k) is easily realized.

[0014] A fifth aspect of this disclosure is that, in any one of the first to third aspects, when viewed in the vertical direction, the area of ​​the wall surface (41k) that overlaps with the fluid inlet (44d) is equal to the area of ​​the fluid inlet (44d).

[0015] In the fifth embodiment, the effect of the fluid colliding with the wall surface (41k) is more easily exhibited.

[0016] A sixth aspect of this disclosure is a configuration in any one of the first to fifth aspects in which the wall surface (41k) is planar and the angle it makes with respect to the upper surface of the fixing member (44) is 0° or more and 45° or less.

[0017] In the sixth embodiment, the effect of the fluid colliding with the wall surface (41k) is realized, while also achieving good fluid flow.

[0018] A seventh aspect of this disclosure is that, in any one of the first to fifth aspects, the wall surface (41k) is curved.

[0019] The seventh embodiment also achieves the effect of the fluid colliding with the wall (41k).

[0020] An eighth aspect of this disclosure is that, in any one of the first to seventh aspects, the wall surface (41k) is formed by a part of the bearing portion (41).

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

[0022] A ninth aspect of this disclosure is that, in any one of the first to eighth aspects, the refrigerant is carbon dioxide.

[0023] Since using carbon dioxide as a refrigerant tends to degrade oil absorption, a remarkable effect is achieved in the ninth embodiment.

[0024] A tenth aspect of this disclosure is a configuration in which the maximum rotational speed exceeds 100 revolutions per second in any one of the first to ninth aspects.

[0025] Since oil consumption tends to deteriorate at high rotational speeds, a remarkable effect is achieved in the tenth embodiment.

[0026] An eleventh aspect of the present disclosure is a refrigeration system (100) equipped with a rotary compressor (1) according to any one of the first to tenth aspects.

[0027] In the eleventh embodiment, it is useful in a rotary compressor equipped with a refrigeration device (100).

[0028] Figure 1 is a schematic diagram showing the configuration of a refrigeration system including a rotary compressor of the present disclosure. Figure 2 is a schematic cross-sectional view showing a rotary compressor of an embodiment of the present disclosure. Figure 3 is a plan view of the piston provided in the rotary compressor of the present disclosure. Figure 4 is a schematic plan view showing a mounting plate (fixing member) in the present disclosure. Figure 5 is a perspective view of the mounting plate shown in Figure 4. Figure 6 is a diagram showing the operation of the rotary compressor. Figure 7 is a cross-sectional view corresponding to the line A-A in Figure 4, and schematically shows a cross-section of a flow path through which a fluid including lubricating oil and refrigerant passes in the present disclosure. Figure 8 is a schematic diagram showing a cross-section of a flow path of a comparative example. Figure 9 is a cross-sectional view showing another example of a flow path in the present disclosure. Figure 10 is a cross-sectional view showing another example of a flow path in the present disclosure. Figure 11 is a cross-sectional view showing another example of a flow path in the present disclosure. Figure 12 is a cross-sectional view showing another example of a flow path in the present disclosure. Figure 13 is a cross-sectional view showing another example of a flow path in the present disclosure. Figure 14 is a cross-sectional view showing another example of a flow path in the present disclosure. Figure 15 is a cross-sectional view showing another example of a flow path in this disclosure. Figure 16 is a plan view showing another configuration of a flow path in this disclosure.

[0029] Embodiments of the present invention will be described in detail below with reference to the drawings. The following description of preferred embodiments is essentially illustrative and is not intended to limit the present invention, its applications, or its uses.

[0030] (Refrigeration System) As shown in Figure 1, the rotary compressor (1) in this example is applied to a refrigeration system (100). The refrigeration system (100) is, for example, an air conditioning system that provides air conditioning to a room. The refrigeration system (100) has an outdoor unit (7) located outside and an indoor unit (8) located inside. The outdoor unit (7) houses the rotary compressor (1), a four-way switching valve (3), an outdoor heat exchanger (4), and an expansion valve (5). The indoor unit (8) houses an indoor heat exchanger (6).

[0031] The refrigeration system (100) includes a refrigerant circuit (9). A rotary compressor (1), an accumulator (2), a four-way switching valve (3), an outdoor heat exchanger (4), an expansion valve (5), and an indoor heat exchanger (6) are connected to the refrigerant circuit (9). The refrigeration cycle is performed by the flow of refrigerant through the refrigerant circuit (9).

[0032] (Rotary Compressor) The compressor (1) in this embodiment is a rotary compressor. The compressor (1) is connected to a refrigerant circuit (9) in which the refrigerant circulates to perform a refrigeration cycle, and compresses the refrigerant. As shown in Figure 2, the compressor (1) has a casing (10), an electric motor (20), and a compression mechanism (30). The electric motor (20) and the compression mechanism (30) are housed inside the casing (10). The compressor (1) is configured as a so-called high-pressure dome type in which the refrigerant compressed in the compression mechanism (30) is discharged into the internal space (S) of the casing (10), and the internal space (S) becomes high pressure.

[0033] The casing (10) comprises a cylindrical body (11) extending vertically, an upper end plate (12) that closes the upper end of the body (11), and a lower end plate (13) that closes the lower end of the body (11). The upper end plate (12) and the lower end plate are formed to be relatively thick. An intake pipe (14) is provided at the lower part of the body (11). The upper end plate (12) is provided with a discharge pipe (15) and a terminal (16) for supplying power to the electric motor (20). An oil reservoir (17) is formed at the bottom of the casing (10). Lubricating oil for lubricating the sliding parts of the compression mechanism (30) is stored in the oil reservoir (17).

[0034] The electric motor (20) is positioned at the top of the body (11) within the casing (10). The placement of the electric motor (20) divides the internal space (S) 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) comprises a cylindrical stator (21) fixed along the inner circumferential surface of the body (11) and a rotor (22) positioned inside the stator (21). Multiple core cuts (23) are formed on the outer circumferential surface of the stator (21). The core cuts (23) connect the first internal space (S1) and the second internal space (S2). Specifically, multiple core cuts (23) are formed in a row in the circumferential direction of the stator (21). The core cuts (23) extend in the axial direction of the stator (21). In this configuration, the refrigerant gas discharged into the first internal space (S1) flows into the second internal space (S2) through the core cut (23).

[0035] The compression mechanism (30) is located below the electric motor (20) within the casing (10). The compression mechanism (30) is fastened to a mounting plate (44), which will be described later, by bolts (73). The compression mechanism (30) comprises 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 the first cylinder chamber. The middle plate (42), the second cylinder (34b), and the rear head (43) constitute the second cylinder chamber.

[0036] The drive shaft (31) is positioned to extend vertically within the casing (10). The upper part of the drive shaft (31) is connected to the rotor (22) of the electric motor (20). The lower part of the drive shaft (31) has, from top to bottom, an upper shaft portion (31a), a first eccentric portion (32a), a central 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 respect to the axis of the drive shaft (31) such that their rotational phase difference is 180°. The first eccentric portion (32a) and the second eccentric portion (32b) are formed to have a larger diameter than the upper shaft portion (31a), the central 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) draws lubricating oil from the oil reservoir (17). An oil supply passage (62) is formed inside the drive shaft (31). The oil supply passage (62) is a passage through which the lubricating oil drawn in by the oil pump (61) flows. The oil supply passage (62) has a main oil supply passage (62a) and a plurality of oil inlets (62b). The main oil supply passage (62a) extends vertically, and its lower end communicates with the oil pump (61). The plurality of oil inlets (62b) extend radially outward from the middle of the main oil supply passage (62a), and their outer ends open to the side of the drive shaft (31). With this configuration, the lubricating oil from the oil reservoir (17) is supplied to the sliding parts of the drive shaft (31) and pistons (35a, 35b).

[0038] Figure 3 is a plan view of the piston. As shown in Figure 3, the first cylinder (34a) and the second cylinder (34b) are both formed in a substantially cylindrical shape. The shafts of the first cylinder (34a) and the second cylinder (34b) are arranged to extend in the vertical direction. The second cylinder (34b) is positioned 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 against both the upper front head (41) and the 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 it. The first roller (36a) is configured to revolve along the inner circumferential surface of the first cylinder (34a) when the drive shaft (31) rotates. A first compression chamber (50a) is formed 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 circumferential surface of the first roller (36a). The first vane (37a) is sandwiched between a pair of first oscillating bushes (54a, 54b) provided in a first bush groove (53a) that extends radially outward from the inner circumferential surface of the first cylinder (34a). The first vane (37a) is configured to restrict the rotation of the first roller (36a) when the first roller (36a) is revolving. The first vane (37a) also divides the first compression chamber (50a) into a first low-pressure chamber (51a) and a first high-pressure chamber (52a).

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

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

[0044] (Mounting Plate) FIG. 4 is a plan view schematically showing the mounting plate (44), corresponding to a view seen from above in FIG. 2. In FIG. 2, in addition to the mounting plate (44), the front head (41) and the body portion (11) are shown. However, for the sake of clarity of the drawing, mainly the elements related to the following description are shown, and some of the elements provided in the front head (41) are omitted. FIG. 5 is a perspective view showing the mounting plate (44).

[0045] As shown in FIGS. 2 and 4, the mounting plate (44) is the fixing member (44) of the present disclosure. The mounting plate (44) is fixed to the body portion (11). The mounting plate (44) is arranged so as to cover from above the front head (41).

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

[0047] The through hole (44c) is a hole for inserting a bolt (73) that fastens the mounting plate (44) and the front head (41). The through hole (44c) is formed at a position corresponding to the fastening hole (41h) of the first disk portion (41b). The six bolts (73) are inserted from the upper side of the mounting plate (44), whereby the mounting plate (44) is fixed to the front head (41).

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

[0049] The longitudinal cross section of the first disk portion (41b) is formed in a convex shape. Specifically, the first disk portion (41b) has a stepped portion (41d) formed around the first boss portion (41c). The lower surface of the first disk portion (41b) is formed flat. The lower surface of the first disk portion (41b) closes the upper end of the first cylinder (34a).

[0050] The first disk portion (41b) is circular, and its outer periphery faces the inner peripheral surface of the peripheral edge portion (44b) of the mounting plate (44). In the vicinity of the outer periphery of the first disk portion (41b), a plurality (six in this example) of fastening holes (41h) and a plurality of fluid outlets (41j) are alternately arranged in the circumferential direction at substantially equal intervals. Also, a first discharge valve (41i) (see FIG. 2; omitted in FIG. 4) is provided near the first boss portion in the first disk portion (41b). The discharge valve is a valve provided at a discharge port (not shown) that communicates the first high-pressure chamber (52a) and a first muffler chamber (R1) described later. 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 more.

[0051] The front head (41) is inserted such that the outer circumferential surface of the stepped portion (41d) of the front head (41) faces the inner surface of the central opening (44e) of the mounting plate (44) (Figure 2). The lower surface of the annular portion (44a) is formed flat and is in contact with 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). A first boss portion (41c) is inserted through the front muffler (71). A first muffler chamber (R1) is formed between the front muffler (71) and the front head (41). The first muffler chamber (R1) is in communication with a first high-pressure chamber (52a) and a second high-pressure chamber (52b). A communication hole (75) is formed in the front muffler (71) that connects the first muffler chamber (R1) and the first internal space (S1).

[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), and closes the gap between the lower end of the first cylinder (34a) and the upper end of the second cylinder (34b). The central shaft portion (31b) of the drive shaft (31) is inserted into this middle plate (42).

[0054] As shown in Figure 2, the rear head (43) is composed of a second disc portion (43b), a second boss portion (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 portion (43a) is formed on the rear head (43). The lower bearing portion (43a) rotatably supports the lower shaft portion (31c) of the drive shaft (31). A second discharge valve (43d) is provided on the second disc portion (43b). The second discharge valve (43d) is a valve provided in a discharge port (not shown) that connects the second high-pressure chamber (52b) and the second muffler chamber (R2), which will be described later. The second discharge valve (43d) is configured to open when the refrigerant pressure in the second high-pressure chamber (52b) exceeds a predetermined value.

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

[0056] (Operation) As shown in Figure 6, in the rotary compressor (1), when the electric motor (20) is started and the rotor (22) is rotated, the drive shaft (31) rotates, and the two eccentric parts (32a, 32b) rotate eccentrically while maintaining a rotational phase difference of 180°. Then, along with the eccentric rotation of these eccentric parts (32a, 32b), the two pistons (35a, 35b) revolve along the inner surface of each cylinder (34a, 34b) while restricting their rotation on their own.

[0057] The suction stroke for drawing refrigerant into the first compression chamber (50a) will now be described. As shown in Figure 5, when the drive shaft (31) rotates slightly from a state of 0° rotation angle (state in Figure 5(A)), the contact point between the first piston (35a) and the first cylinder (34a) passes the inner end of the first suction port (55a). At this time, the suction of refrigerant into the first low-pressure chamber (51a) begins.

[0058] Refrigerant is drawn in through the first suction pipe (14a) and the first suction port (55a). As the rotation angle of the drive shaft (31) increases, the volume of the first low-pressure chamber (51a) gradually increases, and the amount of refrigerant drawn into the first low-pressure chamber (51a) increases (as shown in Figures 5(B) to (H)). This refrigerant suction stroke continues until the rotation angle of the drive shaft (31) reaches 360°, after which the process transitions to the discharge stroke. The refrigerant suction process in the second compression chamber (50b) is the same as the suction process in the first compression chamber (50a).

[0059] Next, the discharge stroke, in which the refrigerant is compressed and discharged in the first compression chamber (50a), will be described. When the drive shaft (31) rotates slightly from the state of 0° rotation angle (state in Figure 5(A)), the contact point between the first piston (35a) and the first cylinder (34a) passes the inner circumference end of the first intake port (55a) again. At this time, the containment of the refrigerant in the first low-pressure chamber (51a) is completed.

[0060] The first low-pressure chamber (51a), which was connected to the first intake port (55a), becomes the first high-pressure chamber (52a), which is connected only to the discharge port (not shown). From this state, compression of the refrigerant in the first high-pressure chamber (52a) begins. As the rotation angle of the drive shaft (31) increases, the volume 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) exceeds a predetermined pressure, the first discharge valve (41i) opens. At this time, the refrigerant in the first high-pressure chamber (52a) is discharged to the first muffler chamber (R1) via the discharge port. The same discharge process as in the first compression chamber (50a) is performed in the second compression chamber (50b). The refrigerant in the second high-pressure chamber (52b) is discharged to the second muffler chamber (R2) via the discharge port. The refrigerant discharged into the second muffler chamber (R2) passes through a connecting 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) through the communication hole (75) of the front muffler (71). This refrigerant flows into the second internal space (S2) through the core cut (23) and between the stator (21) and rotor (22). The gaseous refrigerant that has flowed into the second internal space (S2) is discharged to the outside of the compressor (1) via the discharge pipe (15). This refrigerant discharge stroke continues until the rotation angle of the drive shaft (31) reaches 360°, after which the suction stroke begins.

[0062] Thus, in the rotary compressor (1), the refrigerant is continuously compressed by the alternating suction and discharge strokes in each compression chamber (50a, 50b).

[0063] (Lubrication oil flow path) As described above, the refrigerant compressed in the compression mechanism (30a, 30b) is discharged from the first muffler chamber (R1) into the internal space (S1). Therefore, the pressure of the lubricating oil 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) into the internal space (S1) of the casing (10).

[0064] High-pressure lubricating oil from the oil reservoir (17) is supplied to the compression mechanism (30) through the oil supply passage (62) of the drive shaft (31). The high-pressure lubricating oil supplied to the compression mechanism (30) flows into the gaps between the upper shaft portion (31a) and 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 lubricating oil supplied to the compression mechanism (30) also flows into the gaps 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] Subsequently, a portion of the lubricating oil supplied to the compression mechanism (30) mixes with the refrigerant gas discharged into the first internal space (S1) and is drawn up into the first internal space (S1). A portion of the drawn-up lubricating oil further rises into the second internal space (S2) above the electric motor (20). A further portion of this lubricating oil flows out of the compressor through the discharge pipe (15) along with the refrigerant gas, while the rest passes through the core cut (23) on the outer surface of the stator (21) and falls back into the first internal space (S1). This lubricating oil, along with the lubricating oil that did not rise into the second internal space (S2), falls into the oil reservoir (17).

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

[0067] In relation to this, Figure 7 shows a schematic cross-section corresponding to the line A-A in Figure 4. As described above, the peripheral edge (44b) of the mounting plate (44) is fixed to the inner circumference of the body (11) of the casing (10), and the first disc portion (41b) of the front head (41) is fixed to the mounting plate (44). As shown in Figures 4 and 7, the annular portion (44a) has a fluid inlet (44d) as its opening surface, and a first space (P1) is provided below it. The first disc portion (41b) has a second space (P2), and the opening surface below it is the fluid outlet (41j).

[0068] When viewed in the vertical direction, the fluid inlet (44d) and the fluid outlet (41j) are offset from each other and do not overlap. However, the annular portion (44a) is thinner above the fluid outlet (41j), and the first space (P1) and the second space (P2) are connected. This creates a flow path through which the fluid passes from above the annular portion (44a) to below the first disc portion (41b). Also, when viewed in the vertical direction, the upper surface of the first disc portion (41b) protrudes into the fluid inlet (44d), forming a wall surface (41k) into which the passing fluid collides.

[0069] Because the flow path has this shape, the fluid flowing from the first internal space (S1) to the oil reservoir (17) causes the lubricating oil in the oil reservoir (17) to become mist, which can suppress the cause of oil being kicked up.

[0070] Figure 8 shows a comparative example in which the fluid inlet (44d) and fluid outlet (41j) coincide when viewed in the vertical direction, and there are no walls to which the fluid collides. In this case, the fluid passes through the flow path consisting of the first space (P1) and the second space (P2) without any obstacles and is sprayed onto the surface of the lubricating oil in the oil reservoir 17. As a result, the surface of the lubricating oil is disturbed, causing the lubricating oil to atomize and be stirred up into the first internal space (S1) along with the refrigerant.

[0071] In contrast, in the example shown in Figure 7, there is an obstacle wall (41k) within the flow path, and the fluid passes through the flow path while colliding with the wall (41k). As a result, the fluid does not directly spray onto the liquid surface, but flows into the oil reservoir (17) with reduced force. Therefore, turbulence of the liquid surface caused by the fluid is suppressed, and consequently, the splashing of lubricating oil can be suppressed.

[0072] (Other shapes of flow channels) The shape of the flow channel is not limited to the example in Figure 7. Figure 8 shows an example in which the wall surface (41k) is oblique to the upper surface of the annular portion (44a).

[0073] In other words, in the example of Figure 7, the wall surface (41k) is a plane and is configured parallel to the upper surface of the annular portion (44a). In contrast, in the example of Figure 9, the wall surface (41k) is configured as a plane that makes an angle θ with respect to the upper surface of the annular portion (44a). In this case as well, the fluid passes through the flow path while colliding with the wall surface (41k), and disturbance of the liquid surface in the oil reservoir (17) is suppressed. In addition, the slope makes it easier for the fluid to flow. The angle θ is preferably between 0° and 45°. For the wall surface (41k) to function as an obstacle in the flow path, the angle θ is preferably within this range.

[0074] Furthermore, as shown in Figure 10, the wall surface (41k) may be curved. For example, a curved surface can be effective in controlling the fluid flow. However, since the wall surface (41k) functions as an obstacle that causes the fluid to collide, it must be designed in conjunction with the effect of suppressing oil leakage. Also, although the entire wall surface (41k) is curved in Figure 10, it may be partially curved, such as by giving the corners a rounded shape as in Figure 7.

[0075] Furthermore, as shown in Figure 11, instead of having a portion to reduce the thickness of the plate of the annular portion (44a) above the fluid outlet (41j), a recess may be provided in the first disc portion (41b) below the fluid inlet (44d). This connects the first space (P1) and the second space (P2), which are offset in position when viewed in the vertical direction, thereby forming a flow path.

[0076] In this case as well, the effect of suppressing the splashing of lubricating oil is achieved, similar to the example in Figure 7. Furthermore, when the front head (41) including the first disc portion (41b) is manufactured as a casting, it is easy to achieve such a shape, and in some cases this is preferable to making the annular portion (44a) a complex shape. In addition, in the cases of Figures 9 and 10, it is also possible to configure the device without providing a portion on the fluid outlet (41j) where the thickness of the plate of the annular portion (44a) is reduced.

[0077] Furthermore, in the example shown in Figure 7, when viewed in the vertical direction, the fluid inlet (44d) and the fluid outlet (41j) are offset in position but are adjacent to each other. However, the offset in position can be even larger. This is illustrated in Figure 12. In the case of Figure 12, when viewed in the vertical direction, the fluid inlet (44d) and the fluid outlet (41j) are not adjacent to each other, and they are connected by the gap between the thinned part of the annular section (44a) and the first disc section (41b) (as in Figure 11, a recess may be provided on the side of the first disc section (41b) instead of the annular section (44a) to connect them). Such a shape is acceptable for controlling the state of the fluid flowing into the oil reservoir (17) and for the convenience of the arrangement of the fluid inlet (44d) and the fluid outlet (41j).

[0078] Furthermore, although the wall surface (41k) is formed by the first disc portion (41b) of the front head (41) in the above example, the wall surface (41k) may also be formed by the annular portion (44a), which is part of the mounting plate (44). An example of this is shown in Figure 13. In Figure 13, a portion of the annular portion (44a) is provided extending below the fluid inlet (44d), and its upper surface is used as the wall surface (41k).

[0079] Furthermore, the above describes a configuration in which the fluid inlet (44d) and the first space (P1) are located on the outer circumference side of the compressor (1) (the side closer to the body (11), the left side in Figure 7, etc.), and the fluid outlet (41j) and the second space (P2) are located inside thereof. When fluid flows from the second internal space (S2) above the electric motor (20) to the first internal space (S1) below the electric motor (20), it passes through the core cut (23). In order to move this fluid to the oil reservoir (17), it is preferable that the fluid inlet (44d), which is the entrance to the flow path, is located on the outer circumference side.

[0080] However, as shown in Figure 14, it is also possible to configure the fluid inlet (44d) to be positioned inside the fluid outlet (41j).

[0081] Furthermore, in the above configuration, the fluid inlet (44d) and the fluid outlet (41j) do not overlap when viewed in the vertical direction. In this case, when viewed in the vertical direction, the area of ​​the wall surface (41k) that overlaps with the fluid inlet (44d) is equal to the area of ​​the fluid inlet (44d). This is a desirable configuration from the viewpoint of causing the fluid passing through the flow path to collide with the wall surface (41k), but it is not essential.

[0082] In other words, as shown in Figure 15, when viewed in the vertical direction, the fluid inlet (44d) and the fluid outlet (41j) are offset so that they partially overlap, and the wall surface (41k) may only overlap a portion of the fluid inlet (44d). Even in this case, the effect of suppressing turbulence of the liquid surface in the oil reservoir 17 by causing the fluid to collide with the wall surface (41k) is demonstrated. Here, it is desirable that the area of ​​the wall surface (41k) that overlaps with the fluid inlet (44d) be large, for example, 50% or more.

[0083] Furthermore, in the above configuration, the fluid inlet (44d) and fluid outlet (41j) are offset radially when viewed in the vertical direction, but as shown in Figure 16, they may also be offset circumferentially. Moreover, they may be offset in both the circumferential and radial directions. In this case, the configuration of the first space (P1) and the second space (P2) may be the same as those shown in Figures 7 and 9 to 15.

[0084] Here, it is preferable that the second space (P2) is offset from the first space (P1) in the direction of rotation of the drive shaft (31). The fluid containing lubricating oil and refrigerant is expected to flow along the direction of rotation of the drive shaft (31). Therefore, by arranging the first space (P1) and the second space (P2) in the direction of this flow, the fluid can be made to collide with the wall surface (41k) while maintaining its velocity, and the effect of suppressing the splashing of lubricating oil is easily achieved. However, this does not preclude arranging them in the opposite direction.

[0085] Furthermore, the above describes an example in which the wall surface (41k) is formed by the first disc portion (41b) of the front head (41) or the annular portion (44a) of the mounting plate (44). The wall surface (41k) may also be formed by other members different from these. Other members may include, for example, components other than the first disc portion (41b) in the compression mechanism (30), such as the first cylinder (34a), or an oil separator plate separate from the compression mechanism (30).

[0086] Other Embodiments The compressor (1) of the present disclosure uses carbon dioxide (CO2). ２ ) may be used as a refrigerant. When carbon dioxide is used as a refrigerant, the amount of lubricating oil stirred up increases due to the compatibility and other properties of the refrigerant with the lubricating oil. Therefore, the configuration of this disclosure, which suppresses the stirring up of lubricating oil, is particularly useful.

[0087] Furthermore, the compressor (1) of this disclosure may have multiple cylinders. Since larger capacity compressors tend to produce more lubricating oil, the configuration of this disclosure is particularly useful in large-capacity, multi-cylinder compressors.

[0088] Similarly, the compressor (1) of this disclosure may be a rotary compressor with a maximum rotational speed greater than 100 revolutions per second. In a compressor, the higher the rotational speed, the greater the oil consumption and the more likely a drop in the oil level will occur. In particular, in the case of a compressor using carbon dioxide as a refrigerant, oil consumption increases especially when the rotational speed is greater than 100 revolutions per second, and a drop in the oil level is likely to occur. Therefore, the configuration of this disclosure is particularly useful in a compressor (1) with a maximum rotational speed greater than 100 revolutions per second.

[0089] Furthermore, although we have explained using a so-called swing-type compressor as an example, in which vanes formed integrally with the roller oscillate in accordance with the eccentric rotation of the roller, it is also possible to apply this to so-called rolling piston type compressors, in which vanes separate from the roller contact the roller while the roller rotates eccentrically, and so-called hinge vane type compressors, in which the tips of the vanes are rotatably fitted into recesses on the outer surface of the roller while the roller rotates eccentrically.

[0090] Although embodiments and modifications have been described above, it will be understood that various changes in form and details 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.

[0091] As described above, this disclosure is useful in rotary compressors.

[0092] 1 Rotary Compressor P1 First Space P2 Second Space 10 Casing 11 Body 30 Compression Mechanism 31 Drive Shaft 34a, 34b First Cylinder 36a, 36b First Roller 41 Front Head (Bearing Section) 41j Fluid Outlet 41k Wall Surface 44 Fixing Member (Mounting Plate) 44a Annular Section (First Plate Section) 44d Fluid Inlet 100 Refrigeration System

Claims

1. The device comprises a drive shaft (31) extending in the vertical direction, a compression mechanism (30) connected to the drive shaft (31) for compressing a refrigerant, and a casing (10) housing the drive shaft (31) and the compression mechanism (30) and having a cylindrical body (11), wherein the compression mechanism (30) includes a bearing portion (41) that pivotally supports the drive shaft (31) and is fixed to the casing (10) via a fixing member (44), cylinders (34a, 34b) having a cylinder chamber and positioned below the bearing portion (41), and rollers (36a, 36b) that rotate eccentrically within the cylinder chamber by the drive of the drive shaft (31), wherein the fixing member (44) has a first plate portion (44a) located above the bearing portion (41), and a fluid passage is formed in the fixing member (44) and the compression mechanism (30), and the fluid passage is A rotary compressor (1) comprising: a fluid inlet (44d) provided in the first plate portion (44a); a wall surface (41k) located below the fluid inlet (44d) and upon which the fluid that has passed through the fluid inlet (44d) collides; a first space (P1) between the fluid inlet (44d) and the wall surface (41k); a second space (P2) located at a position offset from the first space (P1) in at least one direction in the radial and circumferential directions and located below the fixing member (44), through which the fluid flows after colliding with the wall surface (41k); and a fluid outlet (41j) provided below the second space (P2).

2. The rotary compressor (1) according to claim 1, characterized in that a part of the second space (P2) is the space sandwiched between the lower surface of the fixing member (44) and the upper surface of the bearing portion (41).

3. The rotary compressor (1) according to claim 1 or 2, characterized in that the bearing portion (41) has a through hole that extends in the vertical direction and is connected to the fluid outlet (41j).

4. A rotary compressor (1) according to any one of claims 1 to 3, characterized in that, when viewed in the vertical direction, the area of ​​the wall surface (41k) in the portion that overlaps with the fluid inlet (44d) is 50% or more of the area of ​​the fluid inlet (44d).

5. A rotary compressor (1) according to any one of claims 1 to 3, characterized in that, when viewed in the vertical direction, the area of ​​the wall surface (41k) in the portion that overlaps with the fluid inlet (44d) is equal to the area of ​​the fluid inlet (44d).

6. A rotary compressor (1) according to any one of claims 1 to 5, characterized in that the wall surface (41k) is flat and the angle it makes with respect to the upper surface of the fixing member (44) is 0° or more and 45° or less.

7. A rotary compressor (1) according to any one of claims 1 to 5, characterized in that the wall surface (41k) is a curved surface.

8. A rotary compressor (1) according to any one of claims 1 to 7, characterized in that the wall surface (41k) is composed of a part of the bearing portion (41).

9. A rotary compressor (1) according to any one of claims 1 to 8, characterized in that the refrigerant is carbon dioxide.

10. A rotary compressor (1) according to any one of claims 1 to 9, characterized in that the maximum rotational speed exceeds 100 revolutions per second.

11. A refrigeration system (100) comprising a rotary compressor (1) according to any one of claims 1 to 10.

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