Rotary compressor and refrigeration apparatus

Abstract

To suppress resistance of oil when a blade enters a back space to allow smooth eccentric rotation of a piston.SOLUTION: A first back space (44) includes a first space (71) on the side where a first blade (47) enters during eccentric rotation of a first piston (45), and a second space (72) on the side to which the first blade (47) retreats. A distance X1 from a virtual center line (L1) to a first position farthest from the virtual center line in the first space (71) and a distance X2 from the virtual center line (L1) to a second position farthest from the virtual center line in the second space (72) satisfy the condition X1>X2.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a swing piston compressor that includes a cylinder, a piston integrally formed with blades (vanes), and a bush (sliding member) that swingably supports the blades.

[0003] In the invention of Patent Document 1, the cylinder is provided with a bush hole (sliding hole) into which a bush is inserted, and a back space (pump hole) that is provided radially outside the bush hole and allows the blade to move back and forth. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-371973 Summary of the Invention [Problem to be solved by the invention]

[0005] However, oil used to lubricate the piston is stored in the back space, so when the blades enter the back space, the resistance of the oil stored in the back space makes it difficult for the piston to rotate eccentrically smoothly, which may result in a decrease in compressor performance.

[0006] An object of the present disclosure is to reduce oil resistance when the blade enters the back space and to allow the piston to rotate eccentrically smoothly. [Means for solving the problem]

[0007] A first aspect of the present disclosure is a rotary compressor including: a cylinder (40) having a cylinder chamber (41) therein; a piston (45) integrally formed with a blade (47) extending in a radial direction and accommodated in the cylinder chamber (41); and a bush (48) inserted into a bush hole (43) provided in the cylinder (40) and supporting the blade (47) so that the blade (47) can swing; wherein the piston (45) rotates eccentrically in the cylinder chamber (41) while the blade (47) swings; and a back wall (41) in the cylinder (40) radially outward of the bush hole (43) in the cylinder (40) where oil is stored and where a tip of the blade (47) can advance and retreat. A rear space (44) is provided, and when viewed in the axial direction of the cylinder (40), a line passing through the center (C1) of the cylinder chamber (41) and the center (C2) of the bush hole (43) is defined as a virtual center line (L1). The rear space (44) includes a first space (71) on the side where the blade (47) advances during eccentric rotation of the piston (45), and a second space (72) on the side where the blade (47) retreats. A distance X1 from the virtual center line (L1) to a first position farthest from the first space (71) and a distance X2 from the virtual center line (L1) to a second position farthest from the second space (72) satisfy the condition X1>X2.

[0008] In the first aspect, by making the first space (71) larger than the second space (72), oil resistance when the blade (47) enters the first space (71) of the back space (44) can be reduced, and the piston (45) can be smoothly rotated eccentrically.

[0009] In a second aspect of the present disclosure, in the rotary compressor of the first aspect, the cylinder (40) is provided with a suction passage (42) that draws refrigerant into the cylinder chamber (41), and the first space (71) is provided on the suction passage (42) side of the imaginary center line (L1).

[0010] In the second aspect, by providing the first space (71) closer to the suction passage (42) than the imaginary center line (L1), it is possible to increase the space in the back space (44) on the side into which the blade (47) enters during the eccentric rotation of the piston (45).

[0011] In a third aspect of the present disclosure, in the rotary compressor of the first or second aspect, a straight line that passes through a radial intermediate position in the back space (44) and is perpendicular to the imaginary center line (L1) when viewed from the axial direction of the cylinder (40) is defined as a virtual orthogonal line (L2), and the first position is located radially outward of the virtual orthogonal line (L2).

[0012] In the third aspect, by locating the first position radially outward from the virtual orthogonal line (L2), the distance between the blade (47) entering the first space (71) and the first position becomes large, thereby reducing oil resistance.

[0013] A fourth aspect of the present disclosure is a refrigeration system including the rotary compressor (10) of any one of the first to third aspects and a refrigerant circuit (1a) through which a refrigerant compressed by the rotary compressor (10) flows.

[0014] In a fourth aspect, a refrigeration system including a rotary compressor (10) and a refrigerant circuit (1a) can be provided. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a refrigerant circuit diagram showing the configuration of the refrigeration device of the first embodiment. [Figure 2] FIG. 2 is a vertical cross-sectional view showing the configuration of the rotary compressor. [Figure 3] FIG. 3 is a cross-sectional plan view showing the configuration of the first cylinder and the first piston. [Figure 4] FIG. 4 is a cross-sectional plan view showing the configuration of the second cylinder and the second piston. [Figure 5] FIG. 5 is a cross-sectional plan view showing a state in which the first blade has entered the first space. [Figure 6]FIG. 6 is a cross-sectional plan view showing a state in which the first blade is retracted from the second space. [Figure 7] FIG. 7 is a cross-sectional plan view showing the configuration of the first cylinder and the first piston according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] First Embodiment As shown in Fig. 1, the rotary compressor (10) is provided in a refrigeration system (1). The refrigeration system (1) has a refrigerant circuit (1a) filled with a refrigerant. The refrigerant circuit (1a) has the rotary compressor (10), a radiator (3), a pressure reduction mechanism (4), and an evaporator (5). The pressure reduction mechanism (4) is, for example, an expansion valve. The refrigerant circuit (1a) performs a vapor compression refrigeration cycle.

[0017] The refrigeration system (1) is an air conditioner. The air conditioner may be a cooling-only unit, a heating-only unit, or an air conditioner that switches between cooling and heating. In this case, the air conditioner has a switching mechanism (e.g., a four-way switching valve) that switches the refrigerant circulation direction. The refrigeration system (1) may be a water heater, a chiller unit, a cooling device that cools the air inside a storage unit, or the like. A cooling device cools the air inside a refrigerator, a freezer, a container, or the like.

[0018] 2, the rotary compressor (10) includes a casing (11), a drive mechanism (20), and a compression mechanism (30). The drive mechanism (20) and the compression mechanism (30) are housed inside the casing (11).

[0019] The casing (11) is a vertically elongated cylindrical sealed container. The casing (11) has a body (12), a lower head (13), and an upper head (14). The body (12) is formed in a cylindrical shape that extends vertically and is open at both ends in the axial direction. The lower head (13) is fixed to the lower end of the body (12). The upper head (14) is fixed to the upper end of the body (12).

[0020] A suction pipe (15) is fixed to and passes through the body (12), and a discharge pipe (16) is fixed to and passes through the upper head (14).

[0021] An oil reservoir (18) is provided at the bottom of the casing (11). The oil reservoir (18) is formed by the lower head (13) and the inner wall of the lower part of the body (12). Oil for lubricating sliding parts of the compression mechanism (30) and the drive shaft (25) is stored in the oil reservoir (18).

[0022] <Drive mechanism> The drive mechanism (20) includes a motor (21) and a drive shaft (25). The motor (21) is disposed above the compression mechanism (30). The motor (21) includes a stator (22) and a rotor (23).

[0023] The stator (22) is fixed to the inner circumferential surface of the body (12) of the casing (11). The rotor (23) extends vertically through the interior of the stator (22). A drive shaft (25) is fixed to the axial center of the rotor (23). When the motor (21) is energized, the drive shaft (25) rotates together with the rotor (23).

[0024] The drive shaft (25) is disposed on the axis of the body (12) of the casing (11). An oil supply pump (25a) is provided at the lower end of the drive shaft (25). The oil supply pump (25a) delivers oil stored in the oil reservoir (18). The delivered oil is supplied to the compression mechanism (30) and the sliding parts of the drive shaft (25) through an oil passage (25b) inside the drive shaft (25).

[0025] The drive shaft (25) has a main shaft portion (26), a first eccentric portion (27), and a second eccentric portion (28). An upper portion of the main shaft portion (26) is fixed to the rotor (23) of the motor (21). The first eccentric portion (27) is disposed above the second eccentric portion (28). The axes of the first eccentric portion (27) and the second eccentric portion (28) are eccentric from the axis of the main shaft portion (26) by a predetermined amount.

[0026] The main shaft portion (26) above the first eccentric portion (27) is rotatably supported by a front head (31) described later. The main shaft portion (26) below the second eccentric portion (28) is rotatably supported by a rear head (33) described later.

[0027] <Compression mechanism> 2, the compression mechanism (30) is a two-cylinder rotary fluid machine. The compression mechanism (30) is disposed below the motor (21). The compression mechanism (30) includes a front head (31), a first cylinder (40), a middle plate (32), a second cylinder (50), and a rear head (33).

[0028] The front head (31), the first cylinder (40), the middle plate (32), the second cylinder (50), and the rear head (33) are stacked in order from top to bottom and fixed by fastening bolts (35).

[0029] The front head (31) is fixed to the body portion (12) of the casing (11). The front head (31) is stacked on top of the first cylinder (40). The front head (31) is arranged so as to cover the first cylinder chamber (41) of the first cylinder (40) from above. The main shaft portion (26) of the drive shaft (25) is inserted through the center of the front head (31). The front head (31) rotatably supports the drive shaft (25). A first discharge passage (49) (see FIG. 3) is formed in the front head (31) and passes through it in the axial direction.

[0030] The first cylinder (40) is formed of a flat, substantially annular member. As shown in Fig. 3, the first cylinder (40) has a first cylinder chamber (41), a first suction passage (42), a first bush hole (43), and a first back space (44).

[0031] The first cylinder chamber (41) is provided in the center of the first cylinder (40). The first suction passage (42) extends from the inner wall surface of the first cylinder chamber (41) toward the outside in the radial direction of the first cylinder (40). The first suction passage (42) opens to the outer surface of the first cylinder (40). The suction pipe (15) is connected to the inflow end of the first suction passage (42). The outflow end of the first suction passage (42) communicates with the first cylinder chamber (41).

[0032] The first cylinder chamber (41) accommodates a first piston (45). The first piston (45) has a first piston body (46) and a first blade (47). The first piston body (46) is formed in an annular shape. The first eccentric portion (27) of the drive shaft (25) is fitted inside the first piston body (46). The first blade (47) is formed integrally with the first piston body (46). The first blade (47) extends radially outward from the first piston body (46).

[0033] The first blade (47) is swingably supported by a pair of first bushes (48). The first bushes (48) are inserted into the first bush holes (43). The inside of the first cylinder chamber (41) is divided into a low-pressure chamber and a high-pressure chamber by the first blades (47).

[0034] As the drive shaft (25) is driven to rotate, the first piston (45) rotates eccentrically in the first cylinder chamber (41) while the blade (47) swings. As the volume of the low-pressure chamber increases gradually with the eccentric rotation of the first piston (45), the refrigerant flowing through the suction pipe (15) is sucked into the low-pressure chamber through the first suction passage (42).

[0035] Next, when the low-pressure chamber is isolated from the first suction passage (42), the isolated space forms a high-pressure chamber. As the volume of the high-pressure chamber gradually decreases, the internal pressure of the high-pressure chamber increases. When the internal pressure of the high-pressure chamber exceeds a predetermined pressure, the refrigerant in the high-pressure chamber flows out of the compression mechanism (30) through the first discharge passage (49). This high-pressure refrigerant flows upward through the internal space of the casing (11) and passes through a core cut (not shown) of the motor (21), etc. The high-pressure refrigerant that has flowed out above the motor (21) is sent to the refrigerant circuit (1a) through the discharge pipe (16).

[0036] The first back space (44) is provided at a position radially outwardly spaced from the first cylinder chamber (41). Specifically, the first back space (44) is provided radially outwardly of the first bushing hole (43). The first back space (44) penetrates the first cylinder (40) in the thickness direction. The first back space (44) accommodates the tip of the first blade (47) so that the tip of the first blade (47) can advance and retreat. The first blade (47) swings in the first back space (44) in association with the eccentric rotation of the first piston body (46). The first back space (44) communicates with an oil supply passage (37) described below. Oil is stored in the first back space (44).

[0037] 2, the middle plate (32) is sandwiched between the first cylinder (40) and the second cylinder (50). The middle plate (32) is arranged so as to cover the first cylinder chamber (41) of the first cylinder (40) from below. The middle plate (32) is arranged so as to cover the second cylinder chamber (51) of the second cylinder (50) from above.

[0038] 4, the second cylinder (50) is formed of a flat, substantially annular member and has a second cylinder chamber (51), a second suction passage (52), a second bushing hole (53), and a second back space (54).

[0039] The second cylinder chamber (51) is provided in the center of the second cylinder (50). The second suction passage (52) extends from the inner wall surface of the second cylinder chamber (51) toward the outside in the radial direction of the second cylinder (50). The second suction passage (52) opens to the outer surface of the second cylinder (50). The suction pipe (15) is connected to the inflow end of the second suction passage (52). The outflow end of the second suction passage (52) communicates with the second cylinder chamber (51).

[0040] The second cylinder chamber (51) accommodates a second piston (55). The second piston (55) has a second piston body (56) and a second blade (57). The second piston body (56) is formed in an annular shape. The second eccentric portion (28) of the drive shaft (25) is fitted inside the second piston body (56). The second blade (57) is formed integrally with the second piston body (56). The second blade (57) extends radially outward from the second piston body (56).

[0041] The second blade (57) is swingably supported by a pair of second bushes (58). The second bushes (58) are inserted into the second bush holes (53). The interior of the second cylinder chamber (51) is divided into a low-pressure chamber and a high-pressure chamber by the second blades (57).

[0042] The operation of the second piston (55) is substantially the same as the operation of the first piston (45), and therefore, a description thereof will be omitted.

[0043] The second back space (54) is provided at a position radially outwardly spaced from the second cylinder chamber (51). Specifically, the second back space (54) is provided radially outwardly of the second bushing hole (53). The second back space (54) penetrates the second cylinder (50) in the thickness direction. The tip of the second blade (57) is accommodated in the second back space (54) so ​​as to be able to advance and retreat. The second blade (57) swings in the second back space (54) in association with the eccentric rotation of the second piston body (56). The second back space (54) communicates with an oil supply passage (37) described below. Oil is stored in the second back space (54).

[0044] As shown in FIG. 2, the rear head (33) is stacked below the second cylinder (50). The rear head (33) is arranged to cover the second cylinder chamber (51) of the second cylinder (50) from below. The main shaft portion (26) of the drive shaft (25) is inserted through the center of the rear head (33). The rear head (33) rotatably supports the drive shaft (25). A second discharge passage (59) (see FIG. 4) is formed in the rear head (33) to pass through in the axial direction. When the internal pressure of the high-pressure chamber of the second cylinder chamber (51) exceeds a predetermined pressure, the refrigerant in the high-pressure chamber flows out of the compression mechanism (30) through the second discharge passage (59).

[0045] A siphon oil supply pipe (36) is connected to the rear head (33). An upper end of the siphon oil supply pipe (36) is connected to an oil supply passage (37). The oil supply passage (37) is provided continuously so as to penetrate the rear head (33), the second cylinder (50), the middle plate (32), and the first cylinder (40). The oil supply passage (37) includes a first back space (44) of the first cylinder (40) and a second back space (54) of the second cylinder (50).

[0046] The lower end of the siphon oil supply pipe (36) opens toward the oil reservoir (18). The siphon oil supply pipe (36) sucks up oil from the oil reservoir (18) and supplies the oil to the first back space (44) and the second back space (54) through the oil supply passage (37).

[0047] <Configuration of accumulator> An accumulator (60) is connected upstream of the rotary compressor (10). The accumulator (60) temporarily stores the refrigerant before it is sucked into the rotary compressor (10), and separates the liquid refrigerant and oil contained in the gas refrigerant into gas and liquid.

[0048] The accumulator (60) includes a sealed container (61), an inlet pipe (62), and an outlet pipe (63). The inlet pipe (62) allows the refrigerant to flow into the sealed container (61). The outlet pipe (63) allows the refrigerant to flow out of the sealed container (61).

[0049] The sealed container (61) is made of a vertically long cylindrical member. An inlet pipe (62) is connected to the top of the sealed container (61). The lower end of the inlet pipe (62) opens at a position near the top of the internal space of the sealed container (61).

[0050] Two outlet pipes (63) are connected to the lower part of the sealed container (61). The upper ends of the outlet pipes (63) extend upward inside the sealed container (61) and open at positions near the top of the internal space of the sealed container (61).

[0051] The lower end of the outlet pipe (63) extends downward from the lower end of the sealed container (61), and then bends toward the suction pipe (15) of the rotary compressor (10) and is connected to the suction pipe (15).

[0052] <Oil resistance in the back space> In the following, only the configuration of the first back space (44) will be described, but the second back space (54) has the same configuration, so the description of the second back space (54) will be omitted.

[0053] Incidentally, oil used to lubricate the first piston (45) is stored in the first back space (44). Therefore, when the first blade (47) enters the first back space (44), the resistance of the oil stored in the first back space (44) makes it difficult for the first piston (45) to rotate eccentrically smoothly, which may result in a decrease in compressor performance.

[0054] Therefore, in this embodiment, the oil resistance when the first blade (47) enters the first back space (44) is reduced, and the first piston (45) can be smoothly rotated eccentrically.

[0055] As shown in FIG. 3, when viewed in the axial direction of the first cylinder (40), a line passing through the center (C1) of the first cylinder chamber (41) and the center (C2) of the first bush hole (43) is defined as a virtual center line (L1).

[0056] The first back space (44) is formed in a substantially rectangular shape. The first back space (44) includes a first space (71) and a second space (72). The first space (71) is the space into which the first blade (47) enters during the eccentric rotation of the first piston (45) (see FIG. 5).

[0057] In the example shown in Figure 3, the first piston (45) rotates clockwise in Figure 3. Therefore, the first space (71) is located to the right of the imaginary center line (L1) of the first back space (44) in Figure 3, that is, on the side of the first suction passage (42).

[0058] The second space (72) is a space to which the first blade (47) retreats during the eccentric rotation of the first piston (45) (see FIG. 6). The second space (72) is a space on the left side of the imaginary center line (L1) of the first back space (44) in FIG. 3.

[0059] The distance from the virtual center line (L1) in the first space (71) to the farthest first position is defined as X1, and the distance from the virtual center line (L1) in the second space (72) to the farthest second position is defined as X2. In this case, the distances X1 and X2 are set to satisfy the condition X1>X2.

[0060] A straight line that passes through a radially intermediate position in the first back space (44) and is perpendicular to the imaginary center line (L1) when viewed from the axial direction of the first cylinder (40) is defined as an imaginary orthogonal line (L2). The first position is located radially outward of the imaginary orthogonal line (L2).

[0061] -Effects of the first embodiment- According to the feature of this embodiment, by making the first space (71) larger than the second space (72), oil resistance when the blade (47) enters the first space (71) of the back space (44) is reduced, and the piston (45) can be smoothly rotated eccentrically.

[0062] According to the feature of this embodiment, by providing the first space (71) closer to the suction passage (42) than the imaginary center line (L1), it is possible to increase the space on the side of the back space (44) into which the blade (47) enters during the eccentric rotation of the piston (45).

[0063] According to the feature of this embodiment, by locating the first position radially outward from the virtual orthogonal line (L2), the distance between the blade (47) entering the first space (71) and the first position becomes large, thereby reducing oil resistance.

[0064] According to a feature of the present embodiment, a refrigeration system including a rotary compressor (10) and a refrigerant circuit (1a) through which the refrigerant compressed by the rotary compressor (10) flows can be provided.

[0065] Second Embodiment Hereinafter, the same parts as those in the first embodiment will be denoted by the same reference numerals, and only the differences will be described.

[0066] As shown in Fig. 7, the first back space (44) is formed in a substantially trapezoidal shape, with the length of the upper side of the first back space (44) in Fig. 7 being greater than the length of the lower side of the first back space (44).

[0067] The first rear space (44) includes a first space (71) and a second space (72). The first space (71) is the space into which the first blade (47) advances during the eccentric rotation of the first piston (45). The second space (72) is the space into which the first blade (47) retreats during the eccentric rotation of the first piston (45).

[0068] The distance from the virtual center line (L1) in the first space (71) to the farthest first position is defined as X1, and the distance from the virtual center line (L1) in the second space (72) to the farthest second position is defined as X2. In this case, the distances X1 and X2 are set to satisfy the condition X1>X2.

[0069] A straight line that passes through a radially intermediate position of the first back space (44) and is perpendicular to the imaginary center line (L1) when viewed from the axial direction of the first cylinder (40) is defined as an imaginary orthogonal line (L2). Since the first back space (44) is formed in a trapezoidal shape with the upper side longer than the lower side in Fig. 7, the first position is located radially outward of the imaginary orthogonal line (L2).

[0070] -Effects of the second embodiment- According to the feature of this embodiment, by locating the first position radially outward from the virtual orthogonal line (L2), the distance between the blade (47) entering the first space (71) and the first position becomes large, thereby reducing oil resistance.

[0071] In addition, by increasing the space on the side of the first space (71) where the first blade (47) enters and reducing the opening area of ​​the first back space (44) compared to when the first back space (44) is formed in a substantially rectangular shape, the rigidity of the first cylinder (40) can be ensured.

[0072] Other Embodiments In the above embodiment, a two-cylinder rotary compressor (10) having a first cylinder (40) and a second cylinder (50) has been described, but this is not limited to this form and may be, for example, a one-cylinder rotary compressor (10) having one cylinder.

[0073] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and detail are possible without departing from the spirit and scope of the claims. Furthermore, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate. Furthermore, the terms "first," "second," "third," etc. in the specification and claims are used to distinguish between terms to which these terms are attached, and do not limit the number or order of those terms. [Industrial Applicability]

[0074] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for rotary compressors and refrigeration devices. [Explanation of symbols]

[0075] 1 Refrigeration equipment 1a Refrigerant circuit 10 Rotary Compressor 40 cylinders (first cylinder) 41 Cylinder chamber (first cylinder chamber) 42 Suction passage (1st suction passage) 43 Bush hole (first bush hole) 44 Back space (first back space) 45 Piston (1st piston) 47 Blade (1st Blade) 48 Bush (1st Bush) 71 1st space 72 Second space C1 center C2 center L1 Virtual center line L2 Virtual orthogonal line

Claims

1. A rotary compressor comprising: a cylinder (40) having a cylinder chamber (41) therein; a piston (45) integrally formed with a radially extending blade (47) and housed in the cylinder chamber (41); and a bush (48) inserted into a bush hole (43) formed in the cylinder (40) and supporting the blade (47) so that the blade (47) can swing; wherein the piston (45) rotates eccentrically in the cylinder chamber (41) while the blade (47) swings, a back space (44) for storing oil and allowing the tip of the blade (47) to move back and forth is provided radially outward of the bush hole (43) in the cylinder (40); When viewed from the axial direction of the cylinder (40), a line passing through the center (C1) of the cylinder chamber (41) and the center (C2) of the bush hole (43) is defined as a virtual center line (L1); the rear space (44) includes a first space (71) on the side into which the blade (47) advances during eccentric rotation of the piston (45) and a second space (72) on the side into which the blade (47) retreats, A distance X1 from the virtual center line (L1) to a first position farthest from the first space (71) and a distance X2 from the virtual center line (L1) to a second position farthest from the second space (72) satisfy the condition X1>X2. Rotary compressor.

2. 2. The rotary compressor of claim 1, The cylinder (40) is provided with a suction passage (42) through which refrigerant is drawn into the cylinder chamber (41), The first space (71) is provided on the suction passage (42) side of the imaginary center line (L1). Rotary compressor.

3. The rotary compressor according to claim 1 or 2, a straight line that passes through a radial intermediate position in the back space (44) and is perpendicular to the imaginary center line (L1) as viewed in the axial direction of the cylinder (40) is defined as an imaginary orthogonal line (L2); The first position is provided radially outward of the virtual orthogonal line (L2). Rotary compressor.

4. A rotary compressor (10) according to claim 1 or 2; a refrigerant circuit (1a) through which the refrigerant compressed by the rotary compressor (10) flows. Refrigeration equipment.

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