Rotary compressor and refrigeration circuit device

Abstract

The displacement volume of a compression mechanism (40) is defined as Vc (cc), the density of a refrigerant at 1.9 Mpa and 75°C is defined as Dg (g / cm3), the number of revolutions of a rotary shaft (30) is defined as N (rps), the volume of a primary space (S1) is defined as V1 (cc), the volume of a secondary space (S2) is defined as V2 (cc), the height of the primary space (S1) is defined as H1 (cm), the height of the secondary space (S2) is defined as H2 (cm), the density of the refrigerating machine oil at 15°C is defined as Do (g / cm3), and the dissolution viscosity of the refrigerating machine oil present at or below the height position of a suction port (71a) is defined as η (mPa·s). A rotary compressor of the present invention satisfies the following relational expressions: N ≥ 100 (rps) and ((8.19 x 10-8 × Vc × Dg + 0.000327) × Vc3.657 × N3.126) / (V1× V2 × H11.867 × H21.556 × Do × η) ≤ 1.0.

Description

Rotary compressor and refrigeration cycle system

[0001] This disclosure relates to rotary compressors and refrigeration cycle devices. A rotary compressor is a compressor that compresses gas in a compression chamber formed in a cylinder by eccentrically rotating a roller within the cylinder. Rotary compressors generally have vanes for partitioning the compression chamber. Rotary compressors include so-called swing type, in which vanes formed integrally with the rollers oscillate with the eccentric rotation of the rollers; so-called rolling piston type, in which vanes separate from the rollers abut the rollers while the rollers rotate eccentrically; and so-called hinge vane type, in which the tips of the vanes are rotatably fitted into recesses on the outer surface of the rollers while the rollers rotate eccentrically.

[0002] Patent Document 1 discloses a refrigeration cycle device. The refrigeration cycle device has a refrigerant circuit. The refrigerant circuit has a rotary compressor, a heat sink, an expansion valve, and an evaporator. When the rotary compressor is operated, the refrigerant in the refrigerant circuit circulates, and the refrigeration cycle is performed.

[0003] In a rotary compressor, the refrigerant compressed by the compression mechanism flows out through the space inside the casing to the refrigerant circuit via the discharge pipe. In this way, the inside of the casing is filled with high-pressure refrigerant.

[0004] An oil reservoir is formed at the bottom of the casing to hold refrigeration oil. The refrigeration oil is used to lubricate the sliding parts of the rotary compressor. The refrigeration oil in the reservoir is drawn in through the intake port of the oil supply pump and supplied to the sliding parts of the compression mechanism and other components through the oil supply passage in the rotating shaft.

[0005] Japanese Patent Publication No. 2023-162986

[0006] Hydrocarbon refrigerants, such as propane, are used as refrigerants in the refrigerant circuits of refrigeration cycle systems. Hydrocarbon refrigerants are natural refrigerants and have an extremely low global warming potential. On the other hand, hydrocarbon refrigerants generally have a molecular structure similar to that of refrigerant oil and have the characteristic of being easily soluble in refrigerant oil. When the refrigerant dissolves in the refrigerant oil, the soluble viscosity of the refrigerant oil decreases, and the viscous resistance of the refrigerant oil decreases. As a result, the refrigerant oil in the casing is more likely to leak out of the discharge pipe into the refrigerant circuit along with the refrigerant, which can increase the oil rise rate (the proportion of refrigerant oil contained in the fluid leaking out of the discharge pipe).

[0007] The purpose of this disclosure is to reduce the rate of oil consumption.

[0008] The first embodiment relates to a rotary compressor. The rotary compressor comprises an electric motor (25), a rotating shaft (30) connected to the electric motor (25), a compression mechanism (40) positioned below the electric motor (25) and driven by the rotating shaft (30) to compress the refrigerant, a casing (21) housing the electric motor (25), the rotating shaft (30), and the compression mechanism (40) and filled with high-pressure refrigerant discharged from the compression mechanism (40), and a lubrication mechanism (70) having a suction port (71a) for drawing in refrigerant oil accumulated at the bottom of the casing (21) and supplying the refrigerant oil to the sliding parts. The compression mechanism (40) includes annular cylinders (51A, 51B), annular rollers (52A, 52B) that rotate eccentrically within the cylinders (51A, 51B), and vanes (53A, 53B) for forming a compression chamber within the cylinders (51A, 51B). The internal space (S) of the casing (21) includes a primary space (S1) between the compression mechanism (40) and the electric motor (25), and a secondary space (S2) above the electric motor (25). A discharge pipe (24) communicating with the secondary space (S2) is connected to the casing (21). The refrigerant is a single refrigerant consisting of a hydrocarbon refrigerant, or a mixed refrigerant containing a hydrocarbon refrigerant. The displacement volume of the compression mechanism (40) is Vc [cc], and the density of the refrigerant at 1.9 MPa and 75°C is Dg [g / cm³]. 3], the rotational speed of the rotating shaft (30) is N [rps], the volume of the primary space (S1) is V1 [cc], the volume of the secondary space (S2) is V2 [cc], the height of the primary space (S1) is H1 [cm], the height of the secondary space (S2) is H2 [cm], and the density of the refrigerant oil at 15°C is Do [g / cm³]. 3 The soluble viscosity of the refrigerant oil present below the height of the suction port (71a) is defined as η [mPa·S]. The rotary compressor has N ≥ 100 [rps] and ((8.19 × 10 -8 ×Vc × Dg + 0.000327) × Vc 3.657 ×N 3.126 ) / (V1×V2×H1 1.867 ×H2 1.556 The relationship ×Do ​​× η) ≤ 1.0 is satisfied.

[0009] Verification results confirmed that even during operation at a rotational speed N of 100 [rps] or higher, the oil consumption rate α can be reduced to 1.0% or less by satisfying the above relationship. Therefore, in the first embodiment, the oil consumption rate α can be reduced to 1.0% or less during operation at a rotational speed N of 100 or higher of the rotating shaft (30).

[0010] In the second aspect, if the total height of the casing (21) is defined as Hc in the first aspect, then H2 / Hc ≤ 0.25.

[0011] In the second embodiment, by setting H2 / Hc ≤ 0.25, the volume of the secondary space (S2) becomes relatively small, and the amount of refrigerant retained in the secondary space (S2) can be reduced. Therefore, the amount of refrigerant used in the refrigeration cycle of the refrigerant circuit (10) can be secured.

[0012] In the third aspect, in the first or second aspect, if the total height of the casing (21) is defined as H, then 0.2 ≤ H² / Hc.

[0013] In the third embodiment, it is possible to suppress the height H2 of the secondary space (S2) from becoming excessively small. As a result, oil can be separated from the refrigerant in the secondary space (S2), thus reducing the oil leakage rate.

[0014] The fourth aspect is that, in any one of the first to third aspects, the refrigeration oil contains any one of polyalkylene glycol, polyvinyl ether, or polyol ester.

[0015] In the fourth aspect, the refrigeration oil contains polyalkylene glycol, polyvinyl ether, or polyol ester. These refrigeration oils have relatively low solubility for hydrocarbon refrigerants. Therefore, it is possible to suppress an increase in the oil separation rate due to the dissolution of the hydrocarbon refrigerant into the refrigeration oil.

[0016] The fifth aspect is that, in any one of the first to fourth aspects, the density Do [g / cm 3 of the refrigerant is 37 [g / cm 3 or more and 44 [g / cm 3 or less.

[0017] In the fifth aspect, since the density Do of the refrigerant is relatively small, the refrigerant circulation amount in the refrigeration cycle becomes small. As a result, the oil separation rate can be reduced.

[0018] The sixth aspect is that, in any one of the first to fifth aspects, the refrigeration oil contains at least one of a extreme pressure additive of phosphoric esters, an antioxidant, and an acid scavenger.

[0019] The seventh aspect is that, in any one of the first to sixth aspects, the refrigeration oil contains an antioxidant or an acid scavenger in an amount of 0.1% by weight or more and 0.5% by weight or less.

[0020] In the seventh aspect, since the antioxidant or the acid scavenger is 0.5% by weight or less based on the weight of the refrigeration oil, it is possible to suppress the dissolution viscosity of the refrigeration oil from becoming excessively low due to an increase in the content of the antioxidant or the acid scavenger. As a result, the oil separation rate can be reduced.

[0021] The eighth aspect is that, in any one of the first to seventh aspects, the refrigeration oil contains a extreme pressure additive in an amount of 1.0% by weight or more and 5.0% by weight or less.

[0022] In the eighth embodiment, the extreme pressure additive is set to 5.0% by weight or less relative to the weight of the refrigeration oil, thereby suppressing the excessive decrease in the solubility viscosity of the refrigeration oil caused by a high content of the extreme pressure additive. As a result, the oil consumption rate can be reduced.

[0023] The ninth aspect is one of the first to eighth aspects, in which the molecular weight of the refrigeration oil is 1000 or more and 1800 or less.

[0024] In the ninth embodiment, by setting the molecular weight of the refrigerant oil to 1000 or more and 1800 or less, the dissolution of hydrocarbon refrigerants into the refrigerant oil can be suppressed. As a result, the rate of oil leakage can be reduced.

[0025] The tenth embodiment relates to a refrigeration cycle device. The refrigeration cycle device has one of the first to ninth compressors (20) and a refrigerant circuit (10) through which a hydrocarbon refrigerant circulates to perform a refrigeration cycle.

[0026] Figure 1 is a piping diagram of the refrigeration cycle system. Figure 2 is a longitudinal cross-sectional view of the compressor. Figure 3 is an enlarged longitudinal cross-sectional view of the main part of the compressor. Figure 4 is a transverse cross-sectional view of the first compression element. Figure 5 is a transverse cross-sectional view of the second compression element. Figure 6 is an enlarged longitudinal cross-sectional view of a part of the compressor to illustrate the primary and secondary spaces.

[0027] Embodiments of this disclosure will be described in detail below with reference to the drawings. This disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of ​​this disclosure. Since the drawings are for conceptual illustration of this disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for ease of understanding.

[0028] (1) Overall Configuration of the Refrigeration Cycle System The refrigeration cycle system of this disclosure is applicable to a stationary air conditioning system (1). As shown in Figure 1, the air conditioning system (1) is a paired system having one outdoor unit (OU) installed outside and one indoor unit (IU) installed inside. The outdoor unit (OU) and the indoor unit (IU) are connected to each other via two connecting pipes.

[0029] The air conditioning system (1) has a refrigerant circuit (10). The refrigerant circuit (10) is filled with refrigerant. The refrigerant circuit (10) performs a refrigeration cycle by circulating the refrigerant. The refrigerant circuit (10) has a compressor (20), an outdoor heat exchanger (11), an expansion valve (12), and an indoor heat exchanger (13). The refrigerant circuit (10) further has a four-way switching valve (14) for switching between a cooling cycle and a heating cycle. The compressor (20), the outdoor heat exchanger (11), and the expansion valve (12) are installed in an outdoor unit (OU), and the indoor heat exchanger (13) is installed in an indoor unit (IU). The expansion valve (12) may also be installed in an indoor unit (IU).

[0030] The compressor (20) draws in the low-pressure refrigerant from the refrigerant circuit (10) and compresses it. The compressor (20) discharges the compressed refrigerant as high-pressure refrigerant back into the refrigerant circuit (10). The outdoor heat exchanger (11) is a fin-and-tube type heat exchanger. The outdoor heat exchanger exchanges heat between the refrigerant in the refrigerant circuit (10) and the outdoor air transported by the outdoor fan (15). The expansion valve (12) is an example of a pressure reduction mechanism for reducing the pressure of the refrigerant. The expansion valve (12) is an electronically controlled expansion valve with an adjustable opening. The indoor heat exchanger (13) is a fin-and-tube type heat exchanger. The indoor heat exchanger exchanges heat between the refrigerant in the refrigerant circuit (10) and the outdoor air transported by the indoor fan (16).

[0031] The four-way switching valve (14) has a first port (P1), a second port (P2), a third port (P3), and a fourth port (P4). The four-way switching valve (14) switches between a first state shown by the solid line in FIG. 1 and a second state shown by the dashed line in FIG. 1. The four-way switching valve (14) in the first state communicates the first port (P1) with the second port (P2) and at the same time communicates the third port (P3) with the fourth port (P4). When the compressor (20) is operated while the four-way switching valve (14) is in the first state, a refrigeration cycle is performed in which the outdoor heat exchanger (11) functions as a radiator (condenser) and the indoor heat exchanger (13) functions as an evaporator. The four-way switching valve (14) in the second state communicates the first port (P1) with the third port (P3) and at the same time communicates the second port (P2) with the fourth port (P4). When the compressor (20) is operated while the four-way switching valve (14) is in the second state, a heating cycle is performed in which the indoor heat exchanger (13) functions as a radiator (condenser) and the outdoor heat exchanger (11) functions as an evaporator.

[0032] (2) Compressor The configuration of the compressor (20) will be described with reference to FIGS. 2 to 6. In the following description, the terms "up" and "down" are based on the direction indicated by the arrow in FIG. 2. Also, in the following description, the "axial direction" means the direction in which the axis (A) of the rotating shaft (30) shown in FIG. 2 extends, the "radial direction" means the direction passing through the axis (A) of the rotating shaft (30) and perpendicular to the axis (A), and the "circumferential direction" means the rotational direction of the rotating shaft (30).

[0033] The compressor (20) is a rotary compressor. The rotary compressor of the present embodiment is a so-called swing type in which vanes (53A, 53B) integrally formed with rollers (52A, 52B) swing as the rollers (52A, 52B) rotate eccentrically.

[0034] The compressor (20) has a casing (21) and a plurality of component parts housed in the casing (21). The plurality of component parts includes an electric motor (25), a rotating shaft (30), a compression mechanism (40), and an oil supply mechanism (70). The electric motor (25) is a drive source for the compression mechanism (40). The rotating shaft (30) is connected to the electric motor (25). Bearings (44, 45) rotatably support the rotating shaft (30). The compression mechanism (40) compresses the refrigerant by being rotationally driven by the rotating shaft (30). The oil supply mechanism (70) supplies refrigeration machine oil, which is lubricating oil, to a plurality of sliding parts.

[0035] (2-1) Casing The casing (21) is a hollow sealed container. An internal space (S) is formed inside the casing (21). The casing (21) is formed in a vertically long shape that extends in the axial direction, strictly speaking, the vertical direction. The casing (21) has a cylindrical body part (21a) that extends in the vertical direction, an upper lid part (21b) that closes the upper end of the body part (21a), and a lower lid part (21c) that closes the lower end of the body part (21a). The lower lid part (21c) constitutes the bottom of the casing (21).

[0036] The internal space (S) of the casing (21) is filled with the discharged refrigerant discharged from the compression mechanism (40). That is, the compressor (20) is a so-called high-pressure dome type. The internal space (S) of the casing (21) includes a primary space (S1) between the compression mechanism (40) and the electric motor (25) and a secondary space (S2) above the electric motor (25).

[0037] An oil reservoir (35) for storing refrigeration machine oil is formed at the bottom of the casing (21). In the oil reservoir (35), the oil level height of the refrigeration machine oil changes according to the operating conditions of the compressor (20) and the air conditioner (1).

[0038] (2-2) The first suction pipe (23A), the second suction pipe (23B), and the discharge pipe (24) are connected to the first suction pipe, the second suction pipe, and the discharge pipe casing (21). The first suction pipe (23A) and the second suction pipe (23B) pass radially through the body (21a). The first suction pipe (23A) and the second suction pipe (23B) are connected to the low-pressure line of the refrigerant circuit (10). The discharge pipe (24) passes axially through the upper cover (21b). The discharge pipe (24) is connected to the high-pressure line of the refrigerant circuit (10).

[0039] (2-3) The electric motor (25) is located in the upper part of the internal space (S). The electric motor (25) has a stator (26) and a rotor (27). The stator (26) is fixed to the inner circumferential surface of the body (21a). The stator (26) is formed in a cylindrical shape when viewed in a cross section perpendicular to the axial direction (horizontal cross section). The rotor (27) is positioned radially inward of the stator (26). The rotor (27) is fixed to the outer circumferential surface of the rotating shaft (30). The electric motor (25) is configured so that its rotational speed can be adjusted by an inverter device. In other words, the electric motor (25) is an inverter-type electric motor in which its operating frequency is variable.

[0040] (2-4) Rotating shaft The rotating shaft (30) is located at the radial center of the internal space (S). The rotating shaft (30) extends vertically. The rotating shaft (30) has a shaft body (31) and a first eccentric portion (32A) and a second eccentric portion (32B) which are radially eccentric from the axis (A) of the shaft body (31). The rotor (27) of the electric motor (25) is connected to the upper part of the shaft body (31). The first eccentric portion (32A) and the second eccentric portion (32B) are formed at the lower part of the shaft body (31). The first eccentric portion (32A) is located above the second eccentric portion (32B). The direction in which the first eccentric portion (32A) is eccentric from the axis (A) and the direction in which the second eccentric portion (32B) is eccentric from the axis are offset by 180° from each other in the circumferential direction.

[0041] (2-5) Overall configuration of the compression mechanism The compression mechanism (40) is located below the electric motor (25). The compression mechanism (40) has, in order from top to bottom, a front head (41), a first cylinder (51A), a middle plate (42), a second cylinder (51B), and a rear head (43). These members are fastened to each other by bolts that extend in the axial direction.

[0042] The compression mechanism (40) of this embodiment comprises a first compression element (C1) and a second compression element (C2). The first compression element (C1) has a first roller (52A) and a first vane (53A). The second compression element (C2) has a second roller (52B) and a second vane (53B). In the compression mechanism (40) of this embodiment, the rollers (52A, 52B) and vanes (53A, 53B) are integrally configured, and the vanes (53A, 53B) oscillate in accordance with the eccentric rotation of the rollers (52A, 52B).

[0043] A first cylinder chamber (54A) is formed inside the first cylinder (51A). The first cylinder chamber (54A) penetrates the first cylinder (51A) in the axial direction. A second cylinder chamber (54B) is formed inside the second cylinder (51B). The second cylinder chamber (54B) penetrates the second cylinder (51B) in the axial direction.

[0044] (2-5-1) The closure members, front head (41), middle plate (42), and rear head (43), are examples of closure members that axially close the cylinder chambers (54A, 54B). The front head (41) has a first closure portion (41a) which is a flat plate with a slightly thick wall in the axial direction, and an upper bearing portion (41b) which extends upward from the radial center of the first closure portion (41a).

[0045] The lower surface of the first closure portion (41a) closes the upper opening surface of the first cylinder chamber (54A). As shown in Figure 4, the first closure portion (41a) has a first discharge port (55A) that communicates with the high-pressure chamber (compression chamber) of the first cylinder chamber (54A). The first discharge port (55A) is opened and closed by a first discharge valve (not shown).

[0046] The upper bearing portion (41b) is formed in a cylindrical shape that extends axially along the rotating shaft (30). The rotating shaft (30) passes through the interior of the upper bearing portion (41b). A first bearing (44) is formed on the inner circumferential surface of the upper bearing portion (41b). The first bearing (44) rotatably supports the main shaft portion of the rotating shaft (30). The first bearing (44) is composed of a sliding bearing, more precisely a journal bearing.

[0047] The middle plate (42) is positioned between the first cylinder (51A) and the second cylinder (51B). The middle plate (42) is formed in an annular shape. The rotating shaft (30) passes through the interior of the middle plate (42). The upper surface of the middle plate (42) closes the lower opening of the first cylinder chamber (54A). The lower surface of the middle plate (42) closes the upper opening of the second cylinder chamber (54B).

[0048] The rear head (43) has a second closure portion (43a) which is a flat plate with a slightly thicker wall in the axial direction, and a lower bearing portion (43b) which extends downward from the radial center of the second closure portion (43a). The upper surface of the second closure portion (43a) closes the lower opening surface of the second cylinder chamber (54B). As shown in Figure 5, the second closure portion (43a) has a second discharge port (55B) which communicates with the high-pressure chamber (compression chamber) of the second cylinder chamber (54B). The second discharge port (55B) is opened and closed by a second discharge valve (not shown).

[0049] The lower bearing portion (43b) is formed in a cylindrical shape that extends axially along the rotating shaft (30). The rotating shaft (30) passes through the interior of the lower bearing portion (43b). A second bearing (45) is formed on the inner circumferential surface of the lower bearing portion (43b). The second bearing (45) rotatably supports the sub-shaft portion of the rotating shaft (30). The second bearing (45) is composed of a sliding bearing, more precisely a journal bearing.

[0050] (2-5-2) Details of the first compression element The first compression element (C1) shown in Figure 4 has a first eccentric portion (32A), a first cylinder (51A), a first roller (52A), a first vane (53A), and a pair of first bushes (56A).

[0051] The first cylinder (51A) is an annular member that is slightly thicker in the axial direction. Inside the first cylinder (51A), a first cylinder chamber (54A) is formed. The first cylinder chamber (54A) is formed in a circular shape when viewed in the axial direction. The first cylinder (51A) has a first intake passage (57A) and a first bush groove (58A) formed therein. The first intake passage (57A) penetrates the first cylinder (51A) radially. The first intake passage (57A) communicates with the first intake pipe (23A).

[0052] The first roller (52A) is positioned in the first cylinder chamber (54A). The first roller (52A) is formed in an annular shape when viewed in the axial direction. The first eccentric part (32A) is fitted inside the first roller (52A). The inner circumferential surface of the first roller (52A) and the outer circumferential surface of the first eccentric part (32A) slide relative to each other. The first eccentric part (32A) causes the first roller (52A) to rotate eccentrically. The first roller (52A) rotates eccentrically along the inner circumferential surface of the first cylinder chamber (54A), forming a seal between itself and the inner circumferential surface of the first cylinder chamber (54A).

[0053] The first bush groove (58A) is formed on the top dead center side (upper side in Figure 3) of the first cylinder (51A). The first bush groove (58A) is formed in a circular shape when viewed in the axial direction. A pair of first bushes (56A) fit into the first bush groove (58A). Each pair of first bushes (56A) has an arc-shaped portion that follows the inner surface of the first bush groove (58A) and flat portions that are continuous with both ends of the arc-shaped portion. The pair of first bushes (56A) are arranged in the first bush groove (58A) so that their respective flat portions face each other. The flat portions of the pair of first bushes (56A) hold the first vane (53A). The pair of first bushes (56A) are configured to swing along the inner surface of the first bush groove (58A). The first vane (53A) is configured to reciprocate radially between the pair of first bushes (56A).

[0054] The first vane (53A) constitutes a partition member that divides the first cylinder chamber (54A) into a low-pressure chamber (L) and a high-pressure chamber (H). The radially inner portion of the first vane (53A) is continuous with the outer surface of the first roller (52A). The low-pressure chamber (L) of the first cylinder chamber (54A) communicates with the first suction passage (57A) and constitutes a suction chamber into which low-pressure refrigerant flows. The high-pressure chamber (H) of the first cylinder chamber (54A) is isolated from the first suction passage (57A) and constitutes a compression chamber for compressing the refrigerant.

[0055] (2-5-3) Details of the second compression element The second compression element (C2) shown in Figure 5 has a second eccentric portion (32B), a second cylinder (51B), a second roller (52B), a second vane (53B), and a pair of second bushes (56B). The basic structure of the second eccentric portion (32B), the second cylinder (51B), the second roller (52B), the second vane (53B), and the pair of second bushes (56B) is the same as that of the first eccentric portion (32A), the first cylinder (51A), the first roller (52A), the first vane (53A), and the pair of first bushes (56A), respectively, so a detailed explanation is omitted. The second cylinder (51B) has a second cylinder chamber (54B), a second intake passage (57B), and a second bush groove (58B). The basic structure of the second cylinder chamber (54B), the second intake passage (57B), and the second bush groove (58B) is the same as that of the first cylinder chamber (54A), the first intake passage (57A), and the first bush groove (58A), respectively, so a detailed explanation is omitted. The second intake passage (57B) is connected to the second intake pipe (23B). The first roller (52A) and the second roller (52B) are 180° out of phase with respect to each other during eccentric rotation.

[0056] (2-6) The oil supply mechanism (70) shown in Figure 3 supplies refrigerant oil from the oil reservoir (35) to multiple sliding parts. The oil supply mechanism (70) is located at the bottom of the rotating shaft (30). The oil supply mechanism (70) includes an oil supply pump (71) and an oil supply passage (72).

[0057] The oil supply pump (71) is located at the lower end of the rotating shaft (30). The oil supply pump (71) is positioned lower than the oil level in the oil reservoir (35). The oil supply pump (71) transports the refrigerant oil from the oil reservoir (35). The oil supply pump (71) has a suction port (71a) for drawing in the refrigerant oil from the oil reservoir (35). The suction port (71a) opens downward toward the bottom of the casing (21). The oil supply pump (71) is a differential pressure type, centrifugal type, or positive displacement type pump.

[0058] The oil supply passage (72) is formed inside the rotating shaft (30). The oil supply passage (72) communicates with the discharge side of the oil supply pump (71). The oil supply passage (72) has a main passage (73) that extends vertically through the axis of the rotating shaft (30) and a plurality of branch passages that extend radially from the main passage (73). The plurality of branch passages include, in order from top to bottom, a first branch passage (74a), a second branch passage (74b), a third branch passage (74c), and a fourth branch passage (74d).

[0059] The first branch channel (74a) is located at the same height as the upper bearing (41b). The outlet of the first branch channel (74a) opens toward the first bearing (44). In other words, the first branch channel (74a) opens toward the sliding part between the first bearing (44) and the rotating shaft (30). The second branch channel (74b) is formed in the first eccentric part (32A). The outlet of the second branch channel (74b) opens toward the inner circumferential surface of the first roller (52A). In other words, the second branch channel (74b) opens toward the sliding part between the first roller (52A) and the first eccentric part (32A). The third branch channel (74c) is formed in the second eccentric part (32B). The outlet of the third branch channel (74c) opens toward the inner circumferential surface of the first roller (52A). In other words, the third branch channel (74c) opens toward the sliding part between the second roller (52B) and the second eccentric part (32B). The fourth branch channel (74d) is at the same height as the lower bearing (43b). The outlet of the fourth branch channel (74d) opens toward the second bearing (45). In other words, the fourth branch channel (74d) opens toward the sliding part between the second bearing (45) and the rotating shaft (30).

[0060] (2-7) When the rotating shaft (30) is rotated by the operating motor (25), the first eccentric part (32A) and the second eccentric part (32B) rotate eccentrically. In the first compression element (C1), as the first roller (52A) rotates eccentrically, low-pressure refrigerant is drawn from the first suction pipe (23A) into the low-pressure chamber (L) of the first cylinder chamber (54A). At the same time, the refrigerant is compressed in the high-pressure chamber (H) of the first cylinder chamber (54A). In the second compression element (C2), as the second roller (52B) rotates eccentrically, low-pressure refrigerant is drawn from the second suction pipe (23B) into the second low-pressure chamber (L) of the first cylinder chamber (54A). At the same time, the refrigerant is compressed in the high-pressure chamber (54B) of the second cylinder chamber (54B).

[0061] When the internal pressure in the compression chamber of the first compression element (C1) rises and the first reed valve opens, high-pressure refrigerant is discharged into the internal space (S) through the first discharge port (55A). When the internal pressure in the compression chamber of the second compression element (C2) rises and the second reed valve opens, high-pressure refrigerant is discharged into the internal space (S) through the second discharge port (55B). The high-pressure refrigerant surrounding the compression mechanism (40) passes above the electric motor (25) and is discharged into the refrigerant circuit (10) via the discharge pipe (24).

[0062] As the rotating shaft (30) rotates, the oil supply pump (71) rotates along with the rotating shaft (30). As a result, the refrigerant oil in the oil reservoir (35) is drawn into the suction port (71a). The oil supply pump (71) sends the refrigerant oil drawn in from the suction port (71a) to each branch channel (74a, 74b, 74c, 74d) via the main channel (73). The refrigerant oil in the first branch channel (74a) is used to lubricate the sliding part of the first bearing (44), the refrigerant oil in the second branch channel (74b) is used to lubricate the sliding part of the first eccentric part (32A), the refrigerant oil in the third branch channel (74c) is used to lubricate the sliding part of the second eccentric part (32B), and the refrigerant oil in the fourth branch channel (74d) is used to lubricate the sliding part of the second bearing (45).

[0063] (3) Refrigerant The refrigerant in this embodiment is a hydrocarbon refrigerant. The hydrocarbon refrigerant in this embodiment is a single refrigerant consisting of propane (R290). Propane has an extremely low global warming potential and is environmentally friendly. On the other hand, hydrocarbon refrigerants such as propane have a molecular structure similar to that of refrigeration oil, and therefore have the characteristic of being easily soluble in refrigeration oil.

[0064] The hydrocarbon refrigerant may be a single refrigerant consisting of isobutane. The refrigerant in the refrigerant circuit (10) may be a mixed refrigerant containing a hydrocarbon refrigerant and at least one other refrigerant. Other refrigerants include, for example, HFC (hydrofluorocarbon) refrigerant, HFO (hydrofluoroolefin) refrigerant, CF ３ Trifluoroiodomethane (I) is used, among other things.

[0065] (4) Refrigerant oil Next, the refrigerant oil used in the refrigerant circuit (10) will be explained. The term "refrigerant oil" as used here refers to a fluid that contains additives such as extreme pressure additives, antioxidants, and acid scavengers in addition to the components used to lubricate sliding parts (lubricating oil).

[0066] The refrigerant oil used in the refrigerant circuit (10) of this embodiment contains either PAG (polyalkylene glycol), PVE (polyvinyl ether), or POE (polyol ester). The refrigerant oil is mainly composed of PAG, PVE, or POE.

[0067] Hydrocarbon refrigerants such as propane have a molecular structure similar to that of refrigeration oil, and therefore dissolve easily in refrigeration oil. In contrast, PAG, PVE, or POE have relatively low compatibility with hydrocarbon refrigerants. For this reason, using PAG, PVE, or POE as the refrigeration oil can suppress the dissolution of the refrigerant into the oil. The refrigeration oil may also be alkylbenzene or mineral oil.

[0068] The refrigerant oil has the characteristic of separating into two layers when the refrigerant pressure is 1.9 [MPa] and the temperature of the refrigerant oil is 75°C. Therefore, the refrigerant oil in the oil reservoir (35) separates into two layers when the refrigerant pressure in the casing (21) is 1.9 [MPa] and the temperature of the refrigerant oil is 75 [°C].

[0069] Generally, refrigerant oil dissolves uniformly with refrigerant. However, by using refrigerant oil with low solubility with refrigerant, a concentration gradient between the refrigerant oil and refrigerant is created in the oil reservoir (35), resulting in a so-called two-layer separation of the refrigerant oil. The refrigerant oil near the surface of the oil reservoir (35) has a lower density of refrigerant, thus forming a layer with high refrigerant solubility. The refrigerant oil near the bottom of the oil reservoir (35) has a higher density of refrigerant, thus forming a layer with low refrigerant solubility. The dissolution viscosity of the refrigerant oil changes depending on the refrigerant solubility. Therefore, the dissolution viscosity of the refrigerant oil can be ensured by suppressing the refrigerant solubility. When refrigerant and refrigerant oil are mixed, the state in which the refrigerant and refrigerant oil do not dissolve and separate into two layers, or an emulsion state, is called a two-layer separation state.

[0070] The molecular weight of the refrigeration oil is preferably between 1000 and 1800.

[0071] The refrigeration oil contains at least one additive, which is an extreme pressure additive of phosphate esters, an antioxidant, and an acid scavenger.

[0072] As extreme pressure additives of phosphate esters, those containing phosphate esters, phosphite esters, acidic phosphate esters, acidic phosphite esters, and amine salts of acidic phosphite esters can be used.

[0073] As acid scavengers, epoxy compounds such as phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxide, and epoxidized soybean oil can be used.

[0074] For antioxidants, phenol-based antioxidants or amine-based antioxidants can be used.

[0075] The refrigeration oil contains 1.0% to 5.0% by weight of extreme pressure additives. The refrigeration oil also contains 0.1% to 0.5% by weight of antioxidants or acid scavengers.

[0076] The refrigerant oil of this embodiment has a surface tension of 0.25 [N / m] or more and 0.40 [N / m] or less at 20°C. The surface tension of the refrigerant oil is measured by a method in accordance with JIS K2241.

[0077] (5) Regarding the parameters of the compressor (5-1) Problem Hydrocarbon refrigerants such as propane have a molecular structure similar to that of refrigeration oil, and therefore have the characteristic of being easily soluble in refrigeration oil. When the refrigerant dissolves in the refrigeration oil, the solubility viscosity of the refrigeration oil decreases, and the viscous resistance of the refrigeration oil decreases. As a result, the refrigeration oil in the casing (21) is more likely to flow out of the discharge pipe (24) into the refrigerant circuit (10) together with the refrigerant, which may increase the rate of oil leakage.

[0078] In addition, because hydrocarbon refrigerants are highly flammable, the amount of refrigerant charged into the refrigerant circuit (10) may be limited to account for the risk of refrigerant leakage. However, since hydrocarbon refrigerants dissolve easily in refrigerant oil, a large amount of refrigerant is retained in the internal space (S) of the compressor (20) together with the refrigerant oil. This leads to a problem where the amount of refrigerant used in the refrigeration cycle of the refrigerant circuit (10) tends to be insufficient. This problem of insufficient refrigerant is particularly pronounced in separate-type air conditioning systems (1) where the indoor unit (IU) and the outdoor unit (OU) are separated, as the refrigerant piping length is relatively long.

[0079] (5-2) Overview of the relational expression Therefore, in order to solve these problems, the compressor (20) of this embodiment is configured to satisfy the following relationship between parameters.

[0080] The displacement volume of the compression mechanism (40) is Vc [cc], and the density of the refrigerant at 1.9 MPa and 75°C is Dg [g / cm³]. 3 ], the rotational speed of the rotating shaft (30) is N [rps], the volume of the primary space (S1) is V1 [cc], the volume of the secondary space (S2) is V2 [cc], the height of the primary space (S1) is H1 [cm], the height of the secondary space (S2) is H2 [cm], the total height of the casing (21) is Hc [cm], and the density of the refrigerant oil at 15°C is Do [g / cm³]. 3 The soluble viscosity of the refrigerant oil present at or below the height position h1 of the suction port (71a) is defined as η [mPa・S], and the oil consumption rate of the rotary compressor is defined as α (weight %).

[0081] The compressor (20) of this embodiment satisfies the following equations (1), (2), (3), and (4).

[0082] N≧100...Equation (1) ((8.19×10 -8 ×Vc × Dg + 0.000327) × Vc 3.657 ×N 3.126 ) / (V1×V2×H1 1.867 ×H2 1.556 ×Do × η) ≤ α, (α = 1.0) ... Equation (2) H2 / Hc ≤ 0.25 ... Equation (3) 0.2 ≤ H2 / Hc ... Equation (4) (5-3) Explanation of each parameter The oil rise rate α is the ratio of the weight Wo of refrigeration oil to the total weight Wt of the fluid flowing out of the discharge pipe (24) as a percentage (α = Wo / Wt × 100).

[0083] As the rotational speed N of the rotating shaft (30) increases, the amount of refrigerant circulating in the refrigerant circuit (10) increases, making it easier for refrigerant oil to leak out of the casing (21) along with the refrigerant. Therefore, as the rotational speed N increases, the oil leakage rate α also increases. In this embodiment, the rotational speed N is 100 [rps] or higher, which is relatively high, so the oil leakage rate tends to increase.

[0084] The displacement volume Vc is the volume of the high-pressure chamber (compression chamber) when the low-pressure chamber (L) is completely closed within the cylinder (51A, 51B) and the high-pressure chamber (compression chamber) is formed, and corresponds to the maximum volume of the compression chamber. The compression mechanism (40) of this embodiment is a two-cylinder type. In this case, the Vc defined here is the sum of the displacement volume Vc-1 of the first cylinder (51A) and the displacement volume Vc-2 of the second cylinder (51B). If the number of cylinders is n, and the displacement volumes of each cylinder are Vc-n, Vc-n+1, ​​..., then the displacement volume Vc is the sum of these displacement volumes Vc-n, Vc-n+1, ​​...

[0085] As the displacement volume Vc increases, the refrigerant circulation rate in the refrigerant circuit (10) increases, making it easier for refrigerant oil to leak out of the casing (21) along with the refrigerant. Therefore, as the displacement volume Vc increases, the oil leakage rate α also increases.

[0086] As the rotational speed N of the rotating shaft (30) increases, the amount of refrigerant circulating in the refrigerant circuit (10) increases, making it easier for refrigerant oil to leak out of the casing (21) along with the refrigerant. Therefore, as the rotational speed N increases, the oil leakage rate α increases. The rotational speed N is preferably 120 [rps] or higher, and more preferably 150 [rps] or higher. The rotational speed N may also be greater than or equal to the maximum rotational speed Nmax of the compressor (20). Here, the maximum rotational speed Nmax is a predetermined value of 100 [rps] or higher, preferably a predetermined value of 120 [rps] or higher, and more preferably a predetermined value of 150 [rps] or higher.

[0087] As shown in Figure 6, the primary space (S1) is the space between the compression mechanism (40) and the electric motor (25). More precisely, the primary space (S1) is the space between the upper end surface of the first closure portion (41a) of the front head (41) and the lower ends of the stator (26) and rotor (27) of the electric motor (25). The upper end surface of the first closure portion (40a) is a flat surface located above the recess where the first reed valve is positioned. The volume V1 of the primary space (S1) corresponds to the volume of this space. However, as shown by the dashed frame of L1 in Figure 6, the volume V1 of the primary space (S1) is calculated ignoring the presence of the upper bearing portion (41b) and the rotating shaft (30). When the volume V1 is large, the refrigerant and oil separate more easily in the primary space (S1), so the oil rise rate α becomes smaller.

[0088] H1 is the height of the primary space (S1). More precisely, as shown in Figure 6, H1 is the maximum height between the upper end surface of the first closing portion (41a) of the front head (41) and the lower ends of the stator (26) and rotor (27). When the height H1 of the primary space (S1) increases, the refrigerant and oil separate more easily in the primary space (S1), so the oil rise rate α decreases.

[0089] As shown in Figure 6, the secondary space (S2) is the space above the electric motor (25). More precisely, the secondary space (S2) is the space between the upper ends of the stator (26) and rotor (27) of the electric motor (25) and the top of the casing (21) (upper cover portion (21b)). The volume V2 of the secondary space (S2) corresponds to the volume of this space. However, as shown by the dashed frame of L2 in Figure 6, the volume V2 of the secondary space (S2) is calculated ignoring the presence of the rotating shaft (30) and the discharge pipe (24). When the volume V2 is large, the refrigerant and oil separate more easily in the secondary space (S2), so the oil rise rate α becomes smaller.

[0090] H2 is the height of the secondary space (S2). More precisely, as shown in Figure 6, H2 is the maximum height between the upper ends of the stator (26) and rotor (27) of the electric motor (25) and the top (upper cover (21b)). When the height H2 of the secondary space (S2) is large, the refrigerant and oil separate more easily in the secondary space (S2), so the oil rise rate α decreases.

[0091] As shown in Figure 2, height Hc is the total height of the casing (21). In other words, height Hc is the maximum height from the bottom end to the top end of the casing (21).

[0092] When the density Dg of the refrigerant increases, the amount of refrigerant circulating in the refrigerant circuit (10) increases, making it easier for the refrigerant oil to leak out of the casing (21) along with the refrigerant. Therefore, when the density Dg of the refrigerant decreases, the oil leakage rate α decreases.

[0093] In this embodiment, the density Dg of the refrigerant is 37 g / cm³. 3 ] or more, 44[g / cm 3 The following applies: The density Dg of the refrigerant is smaller than, for example, the density of an HFC refrigerant. By reducing the density Dg of the refrigerant in this way, the oil leakage rate α can be reduced.

[0094] The density Do of the refrigerant oil is the density of the refrigerant oil. When the density of the refrigerant oil increases, it becomes more difficult for the refrigerant oil to leak out of the casing (21), and the oil leakage rate α decreases.

[0095] The dissolved viscosity η of the refrigerant oil is the dissolved viscosity of the refrigerant oil (hereinafter also referred to as the first refrigerant oil) present in the oil reservoir (35) at a height position h1 or below the suction port (71a) of the oil supply pump (71). The height position h1 of the suction port (71a) refers to the absolute height of the horizontal plane passing through the suction port (71a), as shown in Figure 3. "Dissolved viscosity" refers to the viscosity of the fluid in which the refrigerant is dissolved in the refrigerant oil. The viscosity of this fluid is measured by a method in accordance with JIS K2283. The dissolved viscosity of the refrigerant oil changes depending on the content of the extreme pressure additives, antioxidants, or oxygen scavengers mentioned above.

[0096] When the dissolution viscosity η decreases, the viscous resistance of the refrigeration oil decreases, making it easier for the refrigeration oil to leak out of the casing (21). Therefore, increasing the dissolution viscosity η reduces the oil leakage rate α.

[0097] The dissolution viscosity η is preferably 5.0 or higher. This is because if the dissolution viscosity η is less than 5.0, the amount of wear at the sliding parts of the bearings (44, 45) and the sliding parts of the eccentric parts (32A, 32B) increases sharply. In addition, by increasing the dissolution viscosity η in this way, the oil consumption rate α can be reduced.

[0098] The dissolution viscosity η is preferably 1.2 or less. If the dissolution viscosity η becomes too high, the sliding loss in the eccentric parts (32A, 32B) increases, and the efficiency of the compressor (20) decreases. If the dissolution viscosity is 1.2 or less, the decrease in the efficiency of the compressor (20) can be suppressed.

[0099] As described above, each of the parameters mentioned above affects the oil consumption rate α. The inventors of this application have confirmed through verification that the oil consumption rate α can be expressed by equation (2). Therefore, by satisfying equations (1) and (2) (α = 1.0), the oil consumption rate α can be kept below 1.0 even when the compressor (20) is operated at a rotational speed N of 100 [rps] or higher.

[0100] In this embodiment, as shown in equation (3), H2 / Hc ≤ 0.25. If the height of the secondary space (S2) becomes excessively large relative to the total length of the casing (21), the volume of the secondary space (S2) increases. As described above, hydrocarbon refrigerants are easily soluble in refrigeration oil, so the amount of refrigerant held in the secondary space (S2) tends to increase particularly as the volume of the secondary space (S2) increases. In contrast, by setting H2 / Hc ≤ 0.25, the volume of the secondary space (S2) decreases. As a result, the amount of refrigerant held in the secondary space (S2) can be reduced. Therefore, even if the amount of refrigerant circuit (10) is limited, the amount of refrigerant used in the refrigeration cycle can be secured. In other words, a normal refrigeration cycle can be performed, and the amount of refrigerant circuit (10) can be reduced.

[0101] In this embodiment, as shown in equation (4), 0.2 ≤ H2 / Hc. If the height H2 of the secondary space (S2) is too low, the oil separation rate in the secondary space (S2) decreases, and the oil rise rate α increases. In contrast, by setting 0.2 ≤ H2 / Hc, the function of separating the refrigerant oil in the secondary space (S2) can be ensured, and the oil rise rate α can be reduced.

[0102] (6) Effects of the embodiment (6-1) The refrigerant in this embodiment is a hydrocarbon refrigerant. The rotary compressor has N ≥ 100 [rps] and ((8.19 × 10 -8 ×Vc × Dg + 0.000327) × Vc 3.657 ×N 3.126 ) / (V1×V2×H1 1.867 ×H2 1.556 The relationship ×Do×η)≦α (α=1.0) is satisfied.

[0103] This configuration allows the oil separation rate α to be kept below 1.0 when the compressor (20) is operated at a rotational speed N of 100 [rps] or higher. As a result, shortages of refrigerant oil supplied to the bearings (44, 45) and eccentric parts (32A, 32B) can be suppressed, improving the reliability of the compressor (20).

[0104] (6-2) The compressor (20) of this embodiment satisfies the relationship H2 / Hc ≤ 0.25. This reduces the amount of refrigerant held in the secondary space (S2). Therefore, it is possible to limit the amount of refrigerant charged into the refrigerant circuit (10) while suppressing a shortage of refrigerant used in the refrigeration cycle.

[0105] (6-3) The compressor (20) of this embodiment satisfies the relationship 0.2 ≤ H2 / Hc. This ensures the function of oil separation in the secondary space (S2), thereby reducing the oil rise rate.

[0106] (6-4) The refrigeration oil contains one of the following: polyalkylene glycol, polyvinyl ether, or polyol ester.

[0107] By using these refrigeration oils, hydrocarbon refrigerants are less likely to dissolve into the refrigeration oil. This suppresses a decrease in the viscous resistance of the refrigeration oil, thus reducing the rate of oil consumption. In addition, since the dissolution viscosity of the first refrigeration oil does not become excessively low, wear on sliding parts can be suppressed. In particular, by setting the molecular weight of the refrigeration oil to between 1000 and 1800, the dissolution of hydrocarbon refrigerants into the refrigeration oil can be effectively suppressed.

[0108] In addition, by suppressing the dissolution of hydrocarbon refrigerant into the refrigeration oil in this manner, the amount of refrigerant held within the casing (21) is reduced. Therefore, it is possible to limit the amount of refrigerant charged into the refrigeration circuit (10) while preventing a shortage of refrigerant used in the refrigeration cycle.

[0109] (6-5) The refrigeration oil contains at least one of the following: an extreme pressure additive of phosphate esters, an antioxidant, and an acid scavenger.

[0110] When refrigerant oil contains antioxidants, it contains 0.1% by weight or more and 0.5% by weight or less of antioxidants. Hydrocarbon refrigerants have a chemically stable structure and are less prone to decomposition during the refrigeration cycle compared to HFC and HFO refrigerants. Therefore, even if the amount of antioxidant is 0.5% by weight or less, the refrigerant can be used stably over the long term. Furthermore, by limiting the amount of antioxidant to 0.5% by weight or less, the decrease in viscosity of the refrigerant oil can be suppressed. As a result, the viscous resistance of the refrigerant oil increases, which reduces the oil consumption rate α. In addition, wear on sliding parts can be suppressed.

[0111] When refrigerant oil contains an acid scavenger, it contains 0.1% to 0.5% by weight of the acid scavenger. As mentioned above, hydrocarbon refrigerants have a chemically stable structure and are less prone to decomposition during the refrigeration cycle compared to HFC and HFO refrigerants. Therefore, even if the amount of acid scavenger is 0.5% by weight or less, the refrigerant can be used stably over a long period of time. Furthermore, by limiting the amount of antioxidant to 0.5% by weight or less, the decrease in viscosity of the refrigerant oil can be suppressed. As a result, the viscous resistance of the refrigerant oil increases, which reduces the oil consumption rate α. In addition, wear on sliding parts can be suppressed.

[0112] When refrigeration oil contains extreme pressure additives, it contains 1.0% to 5.0% by weight of extreme pressure additives. By limiting the amount of extreme pressure additives to 5.0% by weight or less, the decrease in viscosity of the refrigeration oil can be suppressed. As a result, the viscous resistance of the refrigeration oil increases, which reduces the oil consumption rate α. In addition, wear on sliding parts can be suppressed.

[0113] (7) Other embodiments: The rotary compressor may be of the so-called rolling piston type, in which vanes separate from the rollers are in contact with the rollers while the rollers rotate eccentrically. The rotary compressor may also be of the so-called hinge vane type, in which the rollers rotate eccentrically with the tips of the vanes rotatably fitted into recesses on the outer surface of the rollers.

[0114] The compression mechanism (40) may have only one cylinder or may have three or more cylinders. In other words, the compression mechanism (40) may have only one compression section or may have three or more compression sections.

[0115] The air conditioning system (1) may be a multi-unit indoor system having multiple indoor units. The air conditioning system (1) may be a movable system that adjusts the temperature of the air in a target space such as a vehicle. The refrigeration cycle system may be a hot water supply system for generating hot water, or a cooling system for generating chilled water. The refrigeration cycle system may be an internal cooling system for cooling the air inside the storage area. The internal cooling system may be a stationary system for warehouses, or a movable system for the interior of transport containers or trailers.

[0116] The rotary compressor (20) may satisfy only equations (1) and (2) above, but it is preferable that it also satisfies equation (3) or (4).

[0117] The first refrigerant oil is the refrigerant oil in the oil reservoir (35) that is below the height of the suction port (71a). However, it is preferable that the first refrigerant oil is the refrigerant oil that is located below the suction port (71a), near the suction port (71a), or inside the suction port (71a).

[0118] While embodiments and modifications have been described above, it will be understood that a variety of changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, the embodiments, modifications, and other embodiments described above may be combined or substituted as appropriate, as long as they do not impair the functions covered by this disclosure.

[0119] The designations "first," "second," "third," etc., mentioned above are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of those terms.

[0120] As described above, this disclosure is useful for rotary compressors and refrigeration cycle systems.

[0121] 1 Air conditioning system (refrigeration cycle system) 10 Refrigerant circuit 20 Compressor 21 Casing 24 Discharge pipe 25 Electric motor 30 Rotating shaft 40 Compression mechanism 51A, 51B Cylinder 52A, 52B Roller 53A, 53B Vane 70 Lubrication mechanism 71a Inlet S Internal space S1 Primary space S2 Secondary space

Claims

1. The apparatus comprises an electric motor (25), a rotating shaft (30) connected to the electric motor (25), a compression mechanism (40) positioned below the electric motor (25) and driven by the rotating shaft (30) to compress the refrigerant, a casing (21) housing the electric motor (25), the rotating shaft (30), and the compression mechanism (40), and filled inside with high-pressure refrigerant discharged from the compression mechanism (40), and a lubrication mechanism (70) having a suction port (71a) for drawing in refrigerant oil accumulated at the bottom of the casing (21) and supplying the refrigerant oil to the sliding parts. The compression mechanism (40) includes an annular cylinder (51A, 51B), annular rollers (52A, 52B) that rotate eccentrically within the cylinder (51A, 51B), and vanes (53A, 53B) for forming a compression chamber within the cylinder (51A, 51B). The internal space (S) of the casing (21) includes a primary space (S1) between the compression mechanism (40) and the electric motor (25), and a secondary space (S2) above the electric motor (25). A discharge pipe (24) communicating with the secondary space (S2) is connected to the casing (21). The refrigerant is a single refrigerant consisting of a hydrocarbon refrigerant, or a mixed refrigerant containing the hydrocarbon refrigerant. The displacement volume of the compression mechanism (40) is Vc [cc], and the density of the refrigerant at 1.9 MPa and 75°C is Dg [g / cm³]. 3 ], the rotational speed of the rotating shaft (30) is N [rps], the volume of the primary space (S1) is V1 [cc], the volume of the secondary space (S2) is V2 [cc], the height of the primary space (S1) is H1 [cm], the height of the secondary space (S2) is H2 [cm], and the density of the refrigerant oil at 15°C is Do [g / cm³]. 3 ], if we define the soluble viscosity of the refrigerant oil present below the height of the suction port (71a) as η [mPa・S], then N ≥ 100 [rps] and ((8.19 × 10 -8 ×Vc × Dg + 0.000327) × Vc 3.657 ×N 3.126 ) / (V1×V2×H1 1.867 ×H2 1.556 A rotary compressor that satisfies the relationship ×Do ​​× η) ≤ 1.

0.

2. The rotary compressor according to claim 1, wherein the total height of the casing (21) is defined as Hc [cm], and H2 / Hc ≤ 0.

25.

3. The rotary compressor according to claim 1 or 2, wherein the total height of the casing (21) is defined as Hc [cm], and 0.2 ≤ H2 / Hc.

4. The rotary compressor according to any one of claims 1 to 3, wherein the refrigeration oil comprises any one of polyalkylene glycol, polyvinyl ether, or polyol ester.

5. The density Do [g / cm 3 of the refrigerant is 37 [g / cm 3 or more and 44 [g / cm 3 or less. The rotary compressor according to any one of claims 1 to 4.

6. The rotary compressor according to any one of claims 1 to 5, wherein the refrigeration oil contains at least one of a phosphate ester extreme pressure additive, an antioxidant, and an acid scavenger.

7. The rotary compressor according to any one of claims 1 to 6, wherein the refrigeration oil contains 0.1% by weight or more and 0.5% by weight or less of an antioxidant or acid scavenger.

8. The rotary compressor according to any one of claims 1 to 7, wherein the refrigeration oil contains 1.0% by weight or more and 5.0% by weight or less of extreme pressure additives.

9. The rotary compressor according to any one of claims 1 to 8, wherein the molecular weight of the refrigeration oil is 1000 or more and 1800 or less.

10. A refrigeration cycle device comprising a rotary compressor (20) according to any one of claims 1 to 9, and a refrigerant circuit (10) that performs a refrigeration cycle using a hydrocarbon refrigerant.

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