Rotary compressor and refrigeration device comprising same

Abstract

In a rotary compressor (10), an electric motor (21) is disposed above a compression mechanism (30) and is connected to the compression mechanism via a drive shaft (25). The compression mechanism has a first cylinder (40) located on the upper side, a second cylinder (50) located on the lower side, a first eccentric portion (44) housed in the first cylinder, and a second eccentric portion (54) housed in the second cylinder. A first balance weight (71) is provided at the lower end of the rotor (23), and a second balance weight (72) is provided at the upper end of the rotor (23). The value of the product of the mass of the second balance weight and the eccentric distance is smaller than the value of the product of the mass of the first balance weight and the eccentric distance.

Description

Technical Field

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

[0002] Conventional rotary compressors include twin-cylinder rotary compressors. Twin-cylinder rotary compressors are vertical compressors that house an electric motor, drive shaft, and compression mechanism within a housing. The motor is positioned above the compression mechanism, and the drive shaft connects the motor's rotor to the compression mechanism.

[0003] The compression mechanism has two cylinders arranged one above the other and an eccentric portion housed in each cylinder. The two eccentric portions are eccentric with a 180-degree phase difference in the circumferential direction relative to the axis of the drive shaft. The interior of each cylinder is divided into a high-pressure chamber and a low-pressure chamber by blades extending radially outward from the piston. Each eccentric portion rotates eccentrically within the cylinder as the drive shaft rotates. Through this action, the compression mechanism draws fluid into the low-pressure chamber, transforming it into a high-pressure chamber, where the fluid is compressed.

[0004] In a twin-cylinder rotary compressor, a balancer is installed on the rotor that constitutes the electric motor. This balancer is used to compensate for the imbalance caused by eccentric rotation in the compression mechanism. The balancer is composed of two balancing weights placed on the upper and lower surfaces of the rotor. An example of such a rotary compressor with a balancer is disclosed in Patent Document 1.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-180203 Summary of the Invention

[0008] -Technical problem to be solved by the invention-

[0009] In a rotary compressor with a balancer as described above, a structure is generally adopted for achieving balance when stationary. Specifically, a structure is adopted in which the lower balancing weight is eccentric in the same direction as the upper eccentric portion, and the upper balancing weight is eccentric in the same direction as the lower eccentric portion. The structure is designed so that the product of the mass of the upper eccentric portion and the eccentric amount is equal to the product of the mass of the lower eccentric portion and the eccentric amount, and the product of the mass of the upper balancing weight and the eccentric distance is equal to the product of the mass of the lower eccentric weight and the eccentric distance.

[0010] However, when the rotary compressor is operating, the pressure of the compressed fluid inside the cylinder acts on the eccentric parts. The resulting compression load is applied to the drive shaft, causing it to deflect slightly. When the drive shaft deflects, the rotor deviates from the pre-set center of rotation. This causes the centrifugal force of the rotor to act together with the inertial force acting on the upper balance weight, exacerbating the deflection of the drive shaft. As a result, during high-speed operation, the static balance between the compression mechanism (two eccentric parts) and the balancer (two balance weights) becomes significantly unbalanced, causing increased vibration.

[0011] The present disclosure aims to reduce vibration of a rotary compressor during high-speed operation.

[0012] -Technical solutions for solving technical problems-

[0013] The first aspect of the present disclosure is directed to a rotary compressor 10. The rotary compressor 10 involved in the first aspect includes a compression mechanism 30, a drive shaft 25, an electric motor 21, and a balancer 70. The compression mechanism 30 sucks in and compresses a fluid, the drive shaft 25 drives the compression mechanism 30, the electric motor 21 has a rotor 23 connected to the drive shaft 25, and the balancer 70 is arranged on the rotor 23. The compression mechanism 30 includes a first cylinder 40 and a second cylinder 50, a first eccentric portion 44, and a second eccentric portion 54. The first cylinder 40 and the second cylinder 50 are arranged in sequence from the rotor 23 side in an axial direction along the axis AC of the drive shaft 25. The first eccentric portion 44 is accommodated inside the first cylinder 40, and the second eccentric portion 54 is accommodated inside the second cylinder 50. The balancer 70 includes a first balancing weight 71 and a second balancing weight 72. The first balancing weight 71 is arranged at one end of the rotor 23 in the axial direction, which is located on the compression mechanism 30 side, and the second balancing weight 72 is arranged at the other end of the rotor 23 in the axial direction. The first eccentric portion 44 and the first balancing weight 71 are eccentric to one side relative to the axis AC of the drive shaft 25, and the second eccentric portion 54 and the second balancing weight 72 are eccentric to the other side relative to the axis AC of the drive shaft 25. In this rotary compressor 10, the first eccentric portion 44 rotates eccentrically inside the first cylinder 40, and the second eccentric portion 54 rotates eccentrically inside the second cylinder 50, in a manner linked to the rotation of the drive shaft 25. Furthermore, when the mass of the first balancing weight 71 is set to m1, the eccentric distance between the center of gravity GC1 of the first balancing weight 71 and the axis AC of the drive shaft 25 is set to r1, the mass of the second balancing weight 72 is set to m2, and the eccentric distance between the center of gravity GC2 of the second balancing weight 72 and the axis AC of the drive shaft 25 is set to r2, the following relationship is satisfied: m1×r1>m2×r2.

[0014] In the first aspect, the product of the mass of the second balancing weight 72 and the eccentric distance (m2 × r2) is smaller than the product of the mass of the first balancing weight 71 and the eccentric distance (m1 × r1). Consequently, when the drive shaft 25 deflects during operation of the rotary compressor 10, the inertial force of the second balancing weight 72, which acts in conjunction with the centrifugal force of the rotor 23 deviating from the predetermined rotation center, can be reduced, thereby suppressing further deflection of the drive shaft 25. This can reduce vibration during high-speed operation of the rotary compressor 10.

[0015] According to a second aspect of the present disclosure, in the rotary compressor ( 10 ) according to the first aspect, the maximum rotational speed of the drive shaft ( 25 ) is greater than or equal to 120 rps.

[0016] In the second aspect, the maximum rotational speed of the drive shaft 25 is relatively high, exceeding 120 rps. In the rotary compressor 10, there is a tendency that as the rotational speed of the drive shaft 25 increases, the static balance between the first and second eccentric portions 44 and 54 and the first and second balance weights 71 and 72 is significantly unbalanced due to deflection of the drive shaft 25, thereby increasing vibration of the rotary compressor 10. Therefore, the disclosed technology is very effective in rotary compressors 10 that operate at relatively high rotational speeds.

[0017] The third aspect of the present disclosure is that, on the basis of the rotary compressor 10 of the first aspect or the second aspect, when the mass of the first eccentric portion 44 is set to m3, the eccentric distance between the center of gravity GC3 of the first eccentric portion 44 and the axis AC of the drive shaft 25 is set to r3, the mass of the second eccentric portion 54 is set to m4, the eccentric distance between the center of gravity GC4 of the second eccentric portion 54 and the axis AC of the drive shaft 25 is set to r4, and the maximum speed of the drive shaft 25 is set to Nmax [rps], the following relationship is satisfied: 1.2-0.002×Nmax≤(m2×r2+m4×r4) / (m1×r1+m3×r3)≤0.98.

[0018] In the third aspect, the static balance relationship value is greater than or equal to 1.2-0.002×Nmax (maximum speed) and less than or equal to 0.98. The static balance relationship value is obtained by dividing the sum of the product of the mass and eccentric distance of the second balancing weight 72 and the product of the mass and eccentric distance of the second eccentric portion 54 (m2×r2+m4×r4) by the sum of the product of the mass and eccentric distance of the first balancing weight 71 and the product of the mass and eccentric distance of the first eccentric portion 44 (m1×r1+m3×r3). This reduces vibration during high-speed operation of the rotary compressor 10, depending on the maximum speed of the drive shaft 25.

[0019] A fourth aspect of the present disclosure is the rotary compressor 10 according to the third aspect, wherein the following relationship is satisfied: 0.88≦(m2×r2+m4×r4) / (m1×r1+m3×r3).

[0020] In the fourth aspect, the static balance relationship value is 0.88 or greater. When the static balance relationship value is less than 0.88, the effect of reducing the vibration of the rotary compressor 10 during high-speed operation can be expected only within a rotational speed range relatively close to the maximum rotational speed of the drive shaft 25. In contrast, when the static balance relationship value is 0.88 or greater, the vibration of the rotary compressor 10 can be reduced within a relatively wide rotational speed range starting from the maximum rotational speed of the drive shaft 25.

[0021] A fifth aspect of the present disclosure is a rotary compressor according to any one of the first to fourth aspects, wherein the sum of the volume of the first compression chamber 41s formed between the inner circumferential surface of the first cylinder 40 and the first eccentric portion 44 and the volume of the second compression chamber 51s formed between the inner circumferential surface of the second cylinder 50 and the second eccentric portion 54 is set to Vcc [cc], and the diameter of the main shaft portion 26 of the drive shaft 25 connected to the rotor 23 is set to Φ [mm], and the following relationship is satisfied: Vcc / Φ 4 ≥3×10 －4 .

[0022] In the fifth aspect, the index value representing the easiness of bending of the main shaft portion 26 is 3×10 －4 The index value described above is obtained by dividing the sum Vcc of the volumes of the first compression chamber 41s and the second compression chamber 51s by the fourth power of the diameter Φ of the main shaft portion 26 of the drive shaft 25. Thus, during operation of the rotary compressor 10, the main shaft portion 26 can be appropriately flexed to achieve static balance between the first and second eccentric portions 44, 54 and the first and second balance weights 71, 72.

[0023] A sixth aspect of the present disclosure is the rotary compressor 10 according to any one of the first to fifth aspects, wherein the diameter of the main shaft portion 26 of the drive shaft 25 connected to the rotor 23 is 16 mm or less. Furthermore, when the mass of the first eccentric portion 44 is m3 [g], the eccentric distance between the center of gravity GC3 of the first eccentric portion 44 and the axis AC of the drive shaft 25 is r3 [mm], the mass of the second eccentric portion 54 is m4 [g], and the eccentric distance between the center of gravity GC4 of the second eccentric portion 54 and the axis AC of the drive shaft 25 is r4 [mm], the following relationship is satisfied: (m3×r3+m4×r4) / 2≥600.

[0024] In the sixth aspect, the diameter of the main shaft portion 26 of the drive shaft 25 is relatively small, being 16 mm or less, and the average value of the product of the mass and the eccentric distance of the first eccentric portion 44 and the second eccentric portion 54 is relatively large, being 600 or greater.

[0025] As a method of suppressing the vibration of the rotary compressor 10 during high-speed operation caused by the deflection of the drive shaft 25, one can consider increasing the diameter of the main shaft portion 26 to improve the rigidity of the drive shaft 25, or reducing the mass and eccentric distance of the first eccentric portion 44 and the second eccentric portion 54, and reducing the size of the rotor 23. However, if the former method is adopted, mechanical losses such as bearing loss will increase, reducing the efficiency of the rotary compressor 10. In addition, if the latter method is adopted, the capacity of the rotary compressor 10 will be limited.

[0026] In contrast, if the diameter of the main shaft portion 26 of the drive shaft 25 is 16 mm or less, mechanical losses such as bearing loss can be reduced, thereby improving the efficiency of the rotary compressor 10. Furthermore, if the average value of the product of the mass of the first eccentric portion 44 and the second eccentric portion 54 and the eccentric distance is 600 or greater, the capacity of the rotary compressor 10 can be relatively large. Consequently, a rotary compressor 10 with low vibration, high efficiency, and high capacity can be realized during high-speed operation.

[0027] The seventh aspect of the present disclosure is directed to a refrigeration device 1. The refrigeration device 1 according to the seventh aspect includes a refrigerant circuit 1a that performs a refrigeration cycle. The refrigerant circuit 1a includes the rotary compressor 10 according to any one of the first to sixth aspects.

[0028] In a seventh aspect, the rotary compressor 10 according to the technology disclosed herein is used in a refrigerant circuit 1a. In the rotary compressor 10, vibration during high-speed operation is reduced. Using the rotary compressor 10 in the refrigerant circuit 1a contributes to a low-vibration and low-noise refrigeration cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a refrigerant circuit diagram showing the structure of a refrigeration device according to an embodiment;

[0030] Figure 2 is a longitudinal sectional view showing the structure of a rotary compressor according to an embodiment;

[0031] Figure 3 is a longitudinal sectional view showing the structure of a compression mechanism according to an embodiment;

[0032] Figure 4 is a transverse cross-sectional view showing the structure of the first cylinder and the first eccentric portion of the embodiment;

[0033] Figure 5 is a transverse cross-sectional view showing the structure of the second cylinder and the second eccentric portion of the embodiment;

[0034] Figure 6 is a longitudinal sectional view showing a main portion (rotary system) of a rotary compressor according to an embodiment;

[0035] Figure 7 is a perspective view showing the structure of a rotor and a balancer according to an embodiment;

[0036] Figure 8 is an exploded perspective view showing the structure of a rotor and a balancer according to an embodiment;

[0037] Figure 9 is a plan view showing a main portion (rotation system) of a rotary compressor according to an embodiment;

[0038] Figure 10 1 is a table showing parameters related to static balance of the rotary systems of the rotary compressors of the comparative example and Examples 1 to 16 and their relationship values ​​to static balance;

[0039] Figure 11 is a graph showing the results of simulations of vibration accelerations generated in the rotary compressors of the comparative example and Examples 1 to 11;

[0040] Figure 12 TABLE 1 is a table showing the results of simulations of vibration accelerations generated in the rotary compressors of the comparative example and Examples 1 to 16 at high-speed rotation speeds.

[0041] Figure 13 It is a transverse cross-sectional view showing the structure of the first cylinder and the first eccentric portion according to another embodiment. DETAILED DESCRIPTION

[0042] Below, exemplary embodiments are described in detail with reference to the accompanying drawings. In the following embodiments, the rotary compressor involved in the technology of the present disclosure is used in a refrigeration device as an example. It should be noted that the accompanying drawings are used to conceptually illustrate the technology of the present disclosure. Therefore, in the accompanying drawings, dimensions, proportions, or quantities may sometimes be exaggerated or simplified to facilitate understanding of the technology of the present disclosure.

[0043] In the following embodiments, the direction along the axis of the drive shaft of the rotary compressor is referred to as the "axial direction," the direction perpendicular to the axial direction is referred to as the "radial direction," and the direction along the circumference of the drive shaft is referred to as the "circumferential direction." Furthermore, the terms "first," "second," etc. are used solely to distinguish between sentences containing the terms and are not intended to limit the number or order of the sentences.

[0044] (Implementation Method)

[0045] like Figure 1 As shown, the rotary compressor 10 of this embodiment is provided in the refrigeration device 1 .

[0046] Refrigeration equipment

[0047] Refrigeration device 1 includes a refrigerant circuit 1a. Refrigerant is filled in refrigerant circuit 1a. Refrigerant is an example of a fluid compressed by a rotary compressor 10. Refrigerant circuit 1a includes rotary compressor 10, radiator 3, pressure reducing mechanism 4, and evaporator 5. Pressure reducing mechanism 4 is, for example, an expansion valve. Refrigerant circuit 1a performs a vapor compression refrigeration cycle.

[0048] In the refrigeration cycle, the gaseous refrigerant compressed by the rotary compressor 10 releases heat to the air in the radiator 3. At this point, the refrigerant liquefies and becomes liquid refrigerant. The liquid refrigerant, having released heat, is decompressed by the decompression mechanism 4. The decompressed liquid refrigerant evaporates in the evaporator 5. At this point, the refrigerant vaporizes and becomes gaseous refrigerant. The evaporated gaseous refrigerant is drawn into the rotary compressor 10. The rotary compressor 10 compresses the drawn gaseous refrigerant.

[0049] The refrigeration device 1 is, for example, an air conditioner. The air conditioner can also be a dual-purpose air conditioner that switches between cooling and heating. In this case, the air conditioner includes a switching mechanism for switching the refrigerant's circulation direction. For example, the switching mechanism is a four-way reversing valve. The air conditioner can also be a dedicated cooling unit or a dedicated heating unit.

[0050] The refrigeration device 1 may also be a water heater, a cooling unit, a cooling device for cooling the air in a storage, etc. The cooling device is a device for cooling the air inside a water heater, a refrigerator, a freezer, a container, etc.

[0051] - Rotary compressor -

[0052] like Figure 2 As shown, rotary compressor 10 is a two-cylinder rotary compressor. The maximum speed of rotary compressor 10 is above 120 rps. The maximum speed referred to here is the speed of drive shaft 25 driven by motor 21 and refers to the highest possible speed within the operating range of the product. Increasing the maximum speed of rotary compressor 10 helps increase the refrigerant circulation volume in refrigerant circuit 1a, thereby ensuring the maximum refrigerant circulation volume.

[0053] The rotary compressor 10 includes a housing 11 , a drive mechanism 20 , a compression mechanism 30 , and a balancer 70 . The drive mechanism 20 , the compression mechanism 30 , and the balancer 70 are accommodated in the housing 11 .

[0054] <case>

[0055] The shell 11 is composed of a cylindrical, sealed container with a long longitudinal length and closed at both ends. The shell 11 is arranged in an upright position. The shell 11 includes a trunk 12, a lower end plate 13, and an upper end plate 14. The trunk 12 is formed into a cylindrical shape extending vertically. The lower end plate 13 is fixed to the lower end of the trunk 12 and closes the lower end opening of the trunk 12. The upper end plate 14 is fixed to the upper end of the trunk 12 and closes the upper end opening of the trunk 12.

[0056] A suction pipe 15 is attached to the lower portion of the trunk 12. The suction pipe 15 passes through the trunk 12 and is connected to the compression mechanism 30. A discharge pipe 16 is attached to the upper end plate 14. The discharge pipe 16 passes through the upper end plate 14 and opens into the upper space inside the housing 11.

[0057] An oil reservoir 18 is formed at the bottom of the housing 11. The oil reservoir 18 is formed by the lower portion of the trunk 12 and the inner walls of the lower end plate 13. Oil is stored in the oil reservoir 18. The oil is used to lubricate the sliding parts of the compression mechanism 30 and the drive shaft 25.

[0058] Drive mechanism

[0059] The drive mechanism (20) includes a motor (21) and a drive shaft (25). The motor (21) is positioned above the compression mechanism (30). The motor (21) includes a stator (22) and a rotor (23). The stator (22) and rotor (23) are each cylindrical. The stator (22) is fixed to the body (12) of the housing (11). The rotor (23) is positioned within the hollow portion of the stator (22).

[0060] End plates 24, each with a hole and a circular plate shape, are provided at each axial end of the rotor 23. A drive shaft 25 is inserted into the hollow portion of the rotor 23. The rotor 23 is fixed to the drive shaft 25. When the motor 21 is energized, the drive shaft 25 rotates integrally with the rotor 23. The drive shaft 25 is the shaft that drives the compression mechanism 30 and extends vertically within the casing 11.

[0061] The drive shaft 25 includes a main shaft portion 26, a first eccentric shaft portion 27, and a second eccentric shaft portion 28. The upper portion of the main shaft portion 26 is connected to the rotor 23. The first eccentric shaft portion 27 and the second eccentric shaft portion 28 are provided near the lower end of the main shaft portion 26. The first eccentric shaft portion 27 is arranged above the second eccentric shaft portion 28. The first eccentric shaft portion 27 and the second eccentric shaft portion 28 are formed so that their diameters are larger than the diameter of the main shaft portion 26.

[0062] The first eccentric shaft portion 27 and the second eccentric shaft portion 28 are eccentrically positioned a predetermined distance from the axis AC of the drive shaft 25 (main shaft portion 26). The first eccentric shaft portion 27 and the second eccentric shaft portion 28 are eccentrically positioned on opposite sides of the axis AC of the drive shaft 25. The portion of the main shaft portion 26 above the first eccentric shaft portion 27 is rotatably supported by the front cylinder head 31. The portion of the main shaft portion 26 below the second eccentric shaft portion 28 is rotatably supported by the rear cylinder head 33.

[0063] A first oil passage 25b is formed within the drive shaft 25. The first oil passage 25b extends to the sliding portion between the compression mechanism 30 and the drive shaft 25. An oil supply pump 25a is provided at the lower end of the drive shaft 25. The oil supply pump 25a is immersed in the oil in the oil reservoir 18. The oil supply pump 25a delivers oil as the drive shaft 25 rotates. The delivered oil is supplied to the sliding portion between the compression mechanism 30 and the drive shaft 25 through the first oil passage 25b.

[0064] Compression mechanism

[0065] The compression mechanism 30 is a mechanism that draws in and compresses the refrigerant and is arranged below the motor 21. The compression mechanism 30 includes a front cylinder head 31, a first cylinder 40, a center plate 32, a second cylinder 50, and a rear cylinder head 33. The front cylinder head 31, the first cylinder 40, the center plate 32, the second cylinder 50, and the rear cylinder head 33 are secured by fastening bolts 35 in an overlapping manner from top to bottom.

[0066] The front cylinder head 31 is fixed to the trunk 12 of the housing 11. The front cylinder head 31 is stacked on top of the first cylinder 40. The front cylinder head 31 is arranged to cover the hollow portion (first cylinder bore 41) of the first cylinder 40 from above. The main shaft portion 26 of the drive shaft 25 is inserted into the center of the front cylinder head 31. The front cylinder head 31 rotatably supports the drive shaft 25.

[0067] The center plate 32 is sandwiched between the first cylinder 40 and the second cylinder 50. The center plate 32 is arranged to cover the hollow portion (first cylinder hole 41) of the first cylinder 40 from below. The center plate 32 is arranged to cover the hollow portion (second cylinder hole 51) of the second cylinder 50 from above.

[0068] The rear cylinder head 33 is stacked on the lower portion of the second cylinder 50. The rear cylinder head 33 is arranged to cover the hollow portion (second cylinder bore 51) of the second cylinder 50 from below. The main shaft portion 26 of the drive shaft 25 is inserted into the center portion of the rear cylinder head 33. The rear cylinder head 33 rotatably supports the drive shaft 25.

[0069] The first cylinder 40 is a thick, generally annular member. A first cylinder bore 41 is formed in the center of the first cylinder 40. The first cylinder bore 41 is a circular hole that penetrates the first cylinder 40 in the thickness direction. The first cylinder bore 41 is formed as a closed space by the front cylinder head 31 and the center plate 32. The first cylinder 40 is fixed to the body 12 of the housing 11 with the centerline of the first cylinder bore 41 oriented in the axial direction (vertical direction).

[0070] like Figure 4 As shown, a first bushing hole 43a and a first vane hole 43b are formed in the first cylinder 40. The first bushing hole 43a and the first vane hole 43b extend through the first cylinder 40 in the axial direction (thickness direction). The first bushing hole 43a and the first vane hole 43b are each formed in a substantially circular shape. The first bushing hole 43a opens toward the first cylinder hole 41. The first vane hole 43b is located radially outside the first bushing hole 43a in the first cylinder 40 and communicates with the first bushing hole 43a.

[0071] A pair of first bushings 48 are embedded in the first bushing hole 43a. Each first bushing 48 is a semi-cylindrical member. The flat surfaces of the pair of first bushings 48 face each other with a gap therebetween. The pair of first bushings 48 are capable of swinging about the centerline of the first bushing hole 43a. The pair of first bushings 48 restrict the rotation of the first piston 45 by clamping the first vane 47, described later.

[0072] A first piston 45 is housed in the first cylinder bore 41. The first piston 45 includes a first roller portion 46 and a first vane 47. The first roller portion 46 is a cylindrical member. The first eccentric shaft portion 27 of the drive shaft 25 is embedded within the first roller portion 46. The outer circumferential surface of the first roller portion 46 is in sliding contact with the inner circumferential surface of the first cylinder 40.

[0073] A space for compressing the refrigerant is formed between the outer circumferential surface of the first roller portion 46 and the inner circumferential surface of the first cylinder 40. This space is a first compression chamber 41s formed by a portion of the first cylinder bore 41. The first roller portion 46 rotates integrally with the first eccentric shaft portion 27. The first roller portion 46 and the first eccentric shaft portion 27 constitute the first eccentric portion 44. In this way, the compression mechanism 30 includes the first eccentric portion 44 housed inside the first cylinder 40. Furthermore, a first compression chamber 41s is formed between the inner circumferential surface of the first cylinder 40 and the first eccentric portion 44.

[0074] The first vane 47 is provided on the outer circumferential surface of the first roller portion 46 and extends radially outward from the first roller portion 46. The first vane 47 is freely movable between the pair of first bushings 48. The tip of the first vane 47 is received in the first vane hole 43b. The space between the outer circumferential surface of the first roller portion 46 and the inner circumferential surface of the first cylinder 40 is divided into a first low-pressure chamber and a first high-pressure chamber by the first vane 47.

[0075] A first suction port 42 is formed on the first cylinder 40. The first suction port 42 penetrates the first cylinder 40 in the radial direction. One end of the first suction port 42 opens on the inner peripheral surface of the first cylinder 40 and is located adjacent to the first bushing 48 ( Figure 4 The first low-pressure chamber is connected to the first suction port 42 at a position adjacent to the right side of the first bushing 48. The other end of the first suction port 42 opens on the outer peripheral surface of the first cylinder 40. The other end of the first suction port 42 is connected to the suction pipe 15.

[0076] A first discharge port 49 is formed in the front cylinder head 31. The first discharge port 49 penetrates the front cylinder head 31 in the axial direction. One end of the first discharge port 49 opens on the lower surface of the front cylinder head 31 and is located at a position ( Figure 4 The first discharge port 49 is connected to the first high-pressure chamber at a position adjacent to the left side of the first bushing 48. The other end of the first discharge port 49 opens on the upper surface of the front cylinder head 31.

[0077] A first discharge valve 60 is provided on the upper surface of the front cylinder head 31. The first discharge valve 60 opens and closes the first discharge port 49. The first discharge valve 60 is, for example, a reed valve. When the air pressure within the first high-pressure chamber is lower than the air pressure within the housing 11 (the pressure within the dome), the first discharge valve 60 is in the closed state, closing the first discharge port 49. When the air pressure within the first high-pressure chamber exceeds the pressure within the dome, the first discharge valve 60 is in the open state, opening the first discharge port 49.

[0078] The second cylinder 50 is a thick, generally annular member. A second cylinder bore 51 is formed in the center of the second cylinder 50. The second cylinder bore 51 is a circular hole that penetrates the second cylinder 50 in the thickness direction. The second cylinder bore 51 is formed as a closed space by the center plate 32 and the rear cylinder head 33. The second cylinder 50 is positioned so that the centerline of the second cylinder bore 51 is oriented in the axial direction (vertical direction).

[0079] like Figure 5 As shown, the second cylinder 50 is formed with a second bushing hole 53a and a second vane hole 53b. The second bushing hole 53a and the second vane hole 53b extend through the second cylinder 50 in the axial direction (thickness direction). The second bushing hole 53a and the second vane hole 53b are each formed in a substantially circular shape. The second bushing hole 53a opens toward the second cylinder hole 51. The second vane hole 53b is located radially outside the second bushing hole 53a in the second cylinder 50 and communicates with the second bushing hole 53a.

[0080] A pair of second bushings 58 are embedded in the second bushing hole 53a. Each second bushing 58 is a semi-cylindrical member. The flat surfaces of the pair of second bushings 58 face each other with a gap therebetween. The pair of second bushings 58 are capable of swinging about the centerline of the second bushing hole 53a. The pair of second bushings 58 restrict the rotation of the second piston 55 by clamping the second vane 57, described later.

[0081] The second cylinder bore 51 houses a second piston 55. The second piston 55 includes a second roller portion 56 and a second vane 57. The second roller portion 56 is a cylindrical member. The second eccentric shaft portion 28 of the drive shaft 25 is embedded within the second roller portion 56. The outer circumferential surface of the second roller portion 56 is in sliding contact with the inner circumferential surface of the second cylinder 50.

[0082] A space for compressing the refrigerant is formed between the outer circumferential surface of the second roller portion 56 and the inner circumferential surface of the second cylinder 50. This space is a second compression chamber 51s formed by a portion of the second cylinder bore 51. The second roller portion 56 rotates integrally with the second eccentric shaft portion 28. The second roller portion 56 and the second eccentric shaft portion 28 constitute the second eccentric portion 54. In this manner, the compression mechanism 30 includes the second eccentric portion 54 housed inside the second cylinder 50. Furthermore, a second compression chamber 51s is formed between the inner circumferential surface of the second cylinder 50 and the second eccentric portion 54.

[0083] The second vane 57 is provided on the outer circumferential surface of the second roller portion 56 and extends radially outward from the second roller portion 56. The second vane 57 is freely movable between the pair of second bushings 58. The tip of the second vane 57 is received in the second vane hole 53b. The space between the outer circumferential surface of the second roller portion 56 and the inner circumferential surface of the second cylinder 50 is divided into a second low-pressure chamber and a second high-pressure chamber by the second vane 57.

[0084] A second suction port 52 is formed on the second cylinder 50. The second suction port 52 penetrates the second cylinder 50 in the radial direction. One end of the second suction port 52 opens on the inner peripheral surface of the second cylinder 50 and is located adjacent to the second bushing 58 ( Figure 5 The second low-pressure chamber is connected to the second suction port 52 at a position adjacent to the right side of the second bushing 58. The other end of the second suction port 52 opens on the outer peripheral surface of the second cylinder 50. The other end of the second suction port 52 is connected to the suction pipe 15.

[0085] A second discharge port 59 is formed in the rear cylinder head 33. The second discharge port 59 penetrates the rear cylinder head 33 in the axial direction. One end of the second discharge port 59 opens on the upper surface of the rear cylinder head 33 and is located at a position ( Figure 5The second discharge port 59 is connected to the second high-pressure chamber at a position on the left side of the second bushing 58. The other end of the second discharge port 59 opens on the lower surface of the rear cylinder head 33.

[0086] A second discharge valve 61 is provided on the lower surface of the rear cylinder head 33. The second discharge valve 61 opens and closes the second discharge port 59. The second discharge valve 61 is, for example, a reed valve. When the air pressure within the second high-pressure chamber is lower than the pressure within the dome, the second discharge valve 61 is in the closed state, closing the second discharge port 59. When the air pressure within the second high-pressure chamber exceeds the pressure within the dome, the second discharge valve 61 is in the open state, opening the second discharge port 59.

[0087] In the compression mechanism (30), the first eccentric portion (44) rotates eccentrically within the first cylinder (40) in conjunction with the rotation of the drive shaft (25). As the volume of the first low-pressure chamber (11) gradually increases with the eccentric rotation of the first eccentric portion (44), refrigerant flowing in the suction pipe (15) is drawn into the first low-pressure chamber (11) through the first suction port (42). When the first eccentric portion (44) continues to rotate eccentrically, disconnecting the first low-pressure chamber from the first suction port (42), the resulting space forms the first high-pressure chamber (11).

[0088] The first eccentric portion (44) further rotates eccentrically, gradually reducing the volume of the first high-pressure chamber, which in turn increases the pressure within the first high-pressure chamber. Furthermore, when the pressure within the first high-pressure chamber exceeds the pressure within the dome, the first discharge valve (60) opens, allowing the refrigerant in the first high-pressure chamber to flow out of the compression mechanism (30) through the first discharge port (49).

[0089] Furthermore, while the first eccentric portion 44 rotates eccentrically, the second eccentric portion 54 rotates eccentrically within the second cylinder 50 in conjunction with the rotation of the drive shaft 25. As the volume of the second low-pressure chamber gradually increases with the eccentric rotation of the second eccentric portion 54, refrigerant flowing in the suction pipe 15 is drawn into the second low-pressure chamber through the second suction port 52. When the second eccentric portion 54 continues to rotate eccentrically, disconnecting the second low-pressure chamber from the second suction port 52, the resulting space forms the second high-pressure chamber.

[0090] The second eccentric portion (54) further rotates eccentrically, gradually reducing the volume of the second high-pressure chamber, which in turn increases the pressure within the second high-pressure chamber. Furthermore, when the pressure within the second high-pressure chamber exceeds the pressure within the dome, the second discharge valve (61) opens, allowing the refrigerant in the second high-pressure chamber to flow out of the compression mechanism (30) through the second discharge port (59).

[0091] The high-pressure refrigerant flowing out of the compression mechanism 30 flows upward in the interior space of the housing 11 and passes through the core cutouts (not shown) of the electric motor 21. The high-pressure refrigerant flowing above the electric motor 21 is then delivered to the refrigerant circuit 1a through the discharge pipe 16.

[0092] like Figure 2 As shown, a siphon oil supply pipe 36 is connected to the rear cylinder head 33. The upper end of the siphon oil supply pipe 36 is connected to the second oil passage 37. The second oil passage 37 is continuously provided through the rear cylinder head 33, the second cylinder 50, the center plate 32, and the first cylinder 40. The lower end of the siphon oil supply pipe 36 is immersed in the oil in the oil reservoir 18. The siphon oil supply pipe 36 draws oil from the oil reservoir 18 and supplies it to the first vane hole 43b and the second vane hole 53b through the second oil passage 37.

[0093] Liquid reservoir

[0094] An accumulator 80 is connected upstream of the rotary compressor 10. The accumulator 80 temporarily stores refrigerant before it is drawn into the rotary compressor 10 and separates the liquid refrigerant and oil contained in the gaseous refrigerant. The accumulator 80 includes a sealed container 81, an inlet pipe 82, and an outlet pipe 83.

[0095] The sealed container 81 is composed of a cylindrical member having a long longitudinal length. The inlet pipe 82 is a pipe body that allows the refrigerant to flow into the sealed container 81. The inlet pipe 82 is connected to the upper portion of the sealed container 81. The lower end of the inlet pipe 82 opens near the upper portion of the internal space of the sealed container 81. The upper end of the inlet pipe 82 is connected to the refrigerant circuit 1a.

[0096] The outlet pipe 83 is a tube that allows the refrigerant to flow out of the sealed container 81. Two outlet pipes 83 are connected to the lower portion of the sealed container 81. The upper end of each outlet pipe 83 extends vertically within the sealed container 81 and opens near the upper portion of the internal space of the sealed container 81. The lower end of each outlet pipe 83 bends after extending downward from the lower end of the sealed container 81 and is connected to the suction pipe 15 of the rotary compressor 10.

[0097] Balancer

[0098] Same as Figures 6 to 8 As shown, the balancer 70 is used to compensate for imbalance caused by eccentric rotation in the compression mechanism 30 and is provided on the rotor 23. The balancer 70 includes a first balancing weight 71 and a second balancing weight 72.

[0099] The first balance weight 71 is a circular plate-shaped component. It is located at one end of the rotor 23, located on the compression mechanism 30 side in the axial direction, i.e., the lower end. The first balance weight 71 is attached to the lower surface of the end plate 24 so that its arc shape extends circumferentially and its two ends are fixed to the lower end plate 24 using two rivets 75.

[0100] The second balance weight 72 is a cylindrical component. It is located at the other end of the rotor 23, located opposite the compression mechanism 30, in the axial direction, i.e., the upper end. The second balance weight 72 is mounted on the upper surface of the end plate 24 with a rivet 75, such that its center portion is fixed to the upper end plate 24, at a position corresponding to the first balance weight 71 across the axis AC of the drive shaft 25 when viewed from above.

[0101] Same as Figure 9 As shown, the first and second balance weights 71, 72 are eccentrically positioned on opposite sides of the axis AC of the drive shaft 25, and are arranged with a 180° phase difference in the circumferential direction. The first balance weight 71 is eccentric in the same direction as the first eccentric portion 44. The first balance weight 71 and the first eccentric portion 44 are in phase with each other. The second balance weight 72 is eccentric in the same direction as the second eccentric portion 54. The second balance weight 72 and the second eccentric portion 54 are in phase with each other.

[0102] In this manner, the first balance weight 71 and the first eccentric portion 44 are eccentric to one side relative to the axis AC of the drive shaft 25, while the second balance weight 72 and the second eccentric portion 54 are eccentric to the other side relative to the axis AC of the drive shaft 25. The first balance weight 71 and the second balance weight 72 balance the forces that tend to translate the drive shaft 25 due to the inertial forces acting on the first eccentric portion 44 and the second eccentric portion 54, thereby maintaining static balance (balance of translational forces).

[0103] <Structure related to static balance during high-speed operation>

[0104] During operation of the rotary compressor 10, the drive shaft 25 deflects slightly under the compressive load from the compression mechanism 30, causing the rotor 23 to deviate from its predetermined center of rotation. Furthermore, the centrifugal force of the rotor 23 and the inertial force acting on the second balance weight 72 act together to exacerbate the deflection of the drive shaft 25. As a result, during high-speed operation, the static balance between the compression mechanism 30 (the first and second eccentric portions 44 and 54) and the balancer 70 (the first and second balance weights 71 and 72) becomes significantly unbalanced, causing increased vibration.

[0105] Therefore, in the rotary compressor 10 of this example, taking into account the fact that when the drive shaft 25 is bent, the centrifugal force of the rotor 23 will act together with the inertial force acting on the second balancing weight 72, the centrifugal force acting on the second balancing weight 72 is made smaller than the centrifugal force acting on the first balancing weight 71, thereby achieving static balance during high-speed operation.

[0106] Specifically, when the mass of the first balancing weight 71 is set to m1 [g], the eccentric distance between the center of gravity GC1 of the first balancing weight 71 and the axis AC of the drive shaft 25 is set to r1 [mm], the mass of the second balancing weight 72 is set to m2 [g], and the eccentric distance between the center of gravity GC2 of the second balancing weight 72 and the axis AC of the drive shaft 25 is set to r2 [mm], the respective masses and eccentric distances of the first balancing weight 71 and the second balancing weight 72 satisfy the relationship shown in the following formula (1).

[0107] m1×r1>m2×r2 ·····(1)

[0108] In addition, in order to achieve static balance of the entire rotating system including the drive mechanism 20, the compression mechanism 30 and the balancer 70, the static balance relationship value corresponding to the ratio of the total centrifugal force acting on the first eccentric portion 44 and the first balancing weight 71 to the total centrifugal force acting on the second eccentric portion 54 and the second balancing weight 72 is adjusted according to the maximum speed of the rotary compressor 10.

[0109] Specifically, when the mass of the first eccentric portion 44 is set to m3 [g], the eccentric distance between the center of gravity GC3 of the first eccentric portion 44 and the axis AC of the drive shaft 25 is set to r3 [mm], the mass of the second eccentric portion 54 is set to m4 [g], the eccentric distance between the center of gravity GC4 of the second eccentric portion 54 and the axis AC of the drive shaft 25 is set to r4 [mm], and the maximum speed of the compression mechanism 30 is set to Nmax [rps], the respective masses and eccentric distances of the first eccentric portion 44, the second eccentric portion 54, the first balance weight 71 and the second balance weight 72 satisfy the relationship shown in the following formula (2).

[0110] 1.2-0.002×Nmax≤(m2×r2+m4×r4) / (m1×r1+m3×r3)≤0.98·····(2)

[0111] The mass of the first eccentric portion 44 is calculated by adding the mass of the first eccentric shaft portion 27 and the mass of the first piston 45. The mass of the second eccentric portion 54 is calculated by adding the mass of the second eccentric shaft portion 28 and the mass of the second piston 55. From the perspective of ensuring a relatively wide rotational speed range in which the vibration of the rotary compressor 10 can be reduced, it is preferred that the respective masses and eccentric distances of the first eccentric portion 44, the second eccentric portion 54, the first balance weight 71, and the second balance weight 72 also satisfy the relationship shown in the following formula (3).

[0112] 0.88≤(m2×r2+m4×r4) / (m1×r1+m3×r3) ·····(3)

[0113] In the rotary compressor 10 of this embodiment, the mass of the first eccentric portion 44 is designed to be equal to the mass of the second eccentric portion 54, and the eccentric distance of the first eccentric portion 44 is equal to the eccentric distance of the second eccentric portion 54. In contrast, the mass of the first balancing weight 71 is smaller than the mass of the second balancing weight 72, and the eccentric distance of the first balancing weight 71 is greater than the eccentric distance of the second balancing weight 72.

[0114] In the rotary compressor 10 of this embodiment, since static balance is achieved in a state where the drive shaft 25 is bent, the diameter of the main shaft portion 26 of the drive shaft 25 is designed to be relatively small to allow for the bending. Figure 3 As shown in FIG, when the diameter of the main shaft portion 26 of the drive shaft 25 is φ [mm], the area moment of inertia Is of the main shaft portion 26 is expressed by the following equation (4). This area moment of inertia is related to the deflection of the main shaft portion 26. The deflection of the main shaft portion 26 is inversely proportional to the fourth power of its diameter φ.

[0115] Is=π×Φ 4 / 64 ·····(4)

[0116] Furthermore, in the rotary compressor 10, there is a tendency that the greater the sum of the volumes of the first compression chamber 41s and the second compression chamber 51s, the greater the sum of the masses of the first eccentric portion 44 and the second eccentric portion 54. Furthermore, the greater the sum of the masses of the first eccentric portion 44 and the second eccentric portion 54, the greater the centrifugal force acting on the main shaft portion 26 of the drive shaft 25 from the compression mechanism 30. Consequently, the deflection of the main shaft portion 26 increases.

[0117] Based on the above, when the sum of the volume of the first compression chamber 41s and the volume of the second compression chamber 51s is defined as Vcc [cc], it is preferable to satisfy the relationship shown in the following formula (5). 4 The value is 3×10 －4In the above case, since the main shaft portion 26 is relatively thin relative to the total volume of the first compression chamber 41s and the second compression chamber 51s, the main shaft portion 26 is easily bent by the centrifugal force generated by the operation of the compression mechanism 30 during the operation of the rotary compressor 10. As described above, when the main shaft portion 26 is relatively thin, the above-mentioned problem of increased vibration during high-speed operation is significantly caused in conventional rotary compressors.

[0118] Vcc / Φ 4 ≥3×10 －4 ·····(5)

[0119] When the inner diameter area of ​​the first cylinder 40 is Sc1, the length of the first cylinder bore 41 is H1, the outer diameter area of ​​the first roller portion 46 is Sr1, and the thickness of the first roller portion 46 is T1, the volume V1 of the first compression chamber 41s is expressed by the following equation (6). Furthermore, when the inner diameter area of ​​the second cylinder 50 is Sc2, the length of the second cylinder bore 51 is H2, the outer diameter area of ​​the second roller portion 56 is Sr2, and the thickness of the second roller portion 56 is T2, the volume V2 of the second compression chamber 51s is expressed by the following equation (7). Furthermore, the sum Vcc of the volumes of the first compression chamber 41s and the second compression chamber 51s is expressed by the following equation (8).

[0120] V1=(Sc1×H1)-(Sr1×T1)·····(6)

[0121] V2=(Sc2×H2)-(Sr2×T2)·····(7)

[0122] Vcc=V1+V2·····(8)

[0123] For example, the diameter of the main shaft portion 26 is less than 16 mm. Furthermore, the sum of the volume of the first compression chamber 41s and the volume of the second compression chamber 51s is, for example, greater than 20 cc. In addition, from the perspective of ensuring the capacity of the rotary compressor 10, the first eccentric portion 44 and the second eccentric portion 54 are designed so that the centrifugal force acting on the first eccentric portion 44 and the second eccentric portion 54 is relatively large. Specifically, the mass and eccentric distance of each of the first eccentric portion 44 and the second eccentric portion 54 satisfy the relationship shown in the following formula (9).

[0124] (m3×r3+m4×r4) / 2≥600 ·····(9)

[0125] Based on the above, a specific example is shown. The mass of the first eccentric portion 44 and the mass of the second eccentric portion 54 are both 187.4g. The eccentric distances of the first eccentric portion 44 and the second eccentric portion 54 are both 4.95mm. In addition, the mass of the first balancing weight 71 is 10.46g. The mass of the second balancing weight 72 is 5.4g. The eccentric distance of the first balancing weight 71 is 18.63mm. The eccentric distance of the second balancing weight 72 is 23.5mm. The static balance relationship value ((m2×r2+m4×r4) / (m1×r1+m3×r3)) in this example is 0.939.

[0126] - Evaluation of vibration suppression effects -

[0127] For the comparison example in which the static balance relationship value ((m2×r2+m4×r4) / (m1×r1+m3×r3)) is 1.0, and embodiments 1 to 16 in which the static balance relationship value takes different values ​​at intervals of 0.01 within the range of 0.84 to 0.99, the vibration acceleration generated during the operation of the rotary compressor 10 was obtained through simulation.

[0128] like Figure 10 As shown, in the rotary compressor 10 of the comparative example and embodiments 1 to 16, the value of the product of the mass of the first balancing weight 71 and the eccentric distance (m1×r1), the value of the product of the mass of the first eccentric portion 44 and the eccentric distance (m3×r3), and the value of the product of the mass of the second eccentric portion 54 and the eccentric distance (m4×r4) are the same, and only the value of the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is different.

[0129] In the rotary compressor 10 of the comparative example and embodiments 1 to 16, the value of the product of the mass of the first balancing weight 71 and the eccentric distance (m1×r1) is 194.9 g·mm, the value of the product of the mass of the first eccentric portion 44 and the eccentric distance (m3×r3), and the value of the product of the mass of the second eccentric portion 54 and the eccentric distance (m4×r4) are the same, which are 927.5 g·mm respectively.

[0130] In the rotary compressor 10 of the comparative example, the value of the product of the mass of the second balance weight 72 and the eccentric distance (m 2 × r 2 ) is 195.1 g·mm, and the static balance relationship value is 1.0.

[0131] In the rotary compressor 10 of Example 1, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 183.8 g·mm, and the static balance relationship value is 0.99. In the rotary compressor 10 of Example 2, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 172.5 g·mm, and the static balance relationship value is 0.98.

[0132] In the rotary compressor 10 of Example 3, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 161.2 g·mm, and the static balance relationship value is 0.97. In the rotary compressor 10 of Example 4, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 149.9 g·mm, and the static balance relationship value is 0.96.

[0133] In the rotary compressor 10 of Example 5, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 138.7 g·mm, and the static balance relationship value is 0.95. In the rotary compressor 10 of Example 6, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 127.6 g·mm, and the static balance relationship value is 0.94.

[0134] In the rotary compressor 10 of Example 7, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 116.3 g·mm, and the static balance relationship value is 0.93. In the rotary compressor 10 of Example 8, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 105.0 g·mm, and the static balance relationship value is 0.92.

[0135] In the rotary compressor 10 of Example 9, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 94.0 g·mm, and the static balance relationship value is 0.91. In the rotary compressor 10 of Example 10, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 82.7 g·mm, and the static balance relationship value is 0.90.

[0136] In the rotary compressor 10 of Example 11, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 71.4 g·mm, and the static balance relationship value is 0.89. In the rotary compressor 10 of Example 12, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 60.2 g·mm, and the static balance relationship value is 0.88.

[0137] In the rotary compressor 10 of Example 13, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 49.0 g·mm, and the static balance relationship value is 0.87. In the rotary compressor 10 of Example 14, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 37.8 g·mm, and the static balance relationship value is 0.86.

[0138] In the rotary compressor 10 of Example 15, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 26.5 g·mm, and the static balance relationship value is 0.85. In the rotary compressor 10 of Example 16, the product of the mass of the second balancing weight 72 and the eccentric distance (m2×r2) is 15.3 g·mm, and the static balance relationship value is 0.84.

[0139] The simulation results for the rotary compressors 10 of the comparative example and embodiments 1 to 11 are plotted as graphs. Figure 11 In. Figure 11 For the sake of convenience, the simulation results of the rotary compressors 10 of Examples 12 to 14 are omitted. Figure 11 As shown, no matter which rotary compressor 10, there is a tendency that as the rotation speed increases, the vibration acceleration first increases and then decreases and reaches a minimum value, and starting from the minimum value, when the rotation speed is further increased, the vibration acceleration will continue to increase.

[0140] Furthermore, the following tendency can be seen: the smaller the static balance relationship value is, the more the minimum value of the vibration acceleration moves toward the high speed side. That is, in the order of the rotary compressor 10 of the comparative example, the rotary compressor 10 of Example 1, the rotary compressor 10 of Example 2, the rotary compressor 10 of Example 3, the rotary compressor 10 of Example 4, the rotary compressor 10 of Example 5, the rotary compressor 10 of Example 6, the rotary compressor 10 of Example 7, the rotary compressor 10 of Example 8, the rotary compressor 10 of Example 9, the rotary compressor 10 of Example 10, and the rotary compressor 10 of Example 11, the speed at which the vibration acceleration takes the minimum value becomes larger.

[0141] Furthermore, the numerical values ​​of vibration acceleration [m / s] of the simulation results of the rotary compressors 10 of the comparative example and Examples 1 to 16 are shown in FIG. 2 ]The speeds of 120rps, 130rps, 140rps, 150rps, 160rps, 170rps and 180rps are shown in Figure 12 In. Figure 12 As shown, in each of the rotary compressors 10 of Examples 1 to 16, the vibration acceleration is smaller than that of the rotary compressor 10 of the comparative example, and the vibration suppression effect during high-speed operation can be confirmed. Figure 12 The values ​​indicating the vibration suppression effect are underlined. This simulation shows that as the static balance relationship value decreases, the vibration suppression effect is achieved only at high speeds, while as the static balance relationship value increases (i.e., closer to 1.0), the vibration suppression effect is achieved over a wide speed range.

[0142] - Features of the first embodiment -

[0143] In the rotary compressor 10 of the first embodiment, the product of the mass of the second balancing weight 72 and the eccentric distance (m2 × r2) is smaller than the product of the mass of the first balancing weight 71 and the eccentric distance (m1 × r1). Consequently, when the drive shaft 25 deflects during operation of the rotary compressor 10, the inertial force of the second balancing weight 72, acting in conjunction with the centrifugal force of the rotor 23 deviating from the predetermined rotation center, is reduced, thereby suppressing further deflection of the drive shaft 25. This reduces vibration during high-speed operation of the rotary compressor 10.

[0144] In the rotary compressor 10 of the first embodiment, the maximum rotational speed is 120 rps or higher, which is relatively high. In the rotary compressor 10, there is a tendency that as the rotational speed of the rotary compressor 10 increases, the static balance between the first and second eccentric portions 44 and 54 and the first and second balancing weights 71 and 72 is significantly unbalanced due to deflection of the drive shaft 25, resulting in increased vibration during operation of the rotary compressor 10. Therefore, the technology disclosed herein is very effective in rotary compressors 10 operating at relatively high rotational speeds.

[0145] In the rotary compressor 10 of the first embodiment, the static balance relationship value is greater than or equal to 1.2-0.002×Nmax (maximum speed) and less than or equal to 0.98. This static balance relationship value is obtained by dividing the sum of the product of the mass and eccentric distance of the second balancing weight 72 and the product of the mass and eccentric distance of the second eccentric portion 54 (m2×r2+m4×r4) by the sum of the product of the mass and eccentric distance of the first balancing weight 71 and the product of the mass and eccentric distance of the first eccentric portion 44 (m1×r1+m3×r3). This reduces vibration during high-speed operation according to the maximum speed of the rotary compressor 10.

[0146] In the rotary compressor 10 of the first embodiment, the static balance relationship value is 0.88 or greater. When the static balance relationship value is less than 0.88, the effect of reducing the vibration of the rotary compressor 10 during high-speed operation can be expected only within a rotational speed range relatively close to the maximum rotational speed of the compression mechanism 30. In contrast, when the static balance relationship value is 0.88 or greater, the vibration of the rotary compressor 10 can be reduced within a relatively wide rotational speed range starting from the maximum rotational speed of the compression mechanism 30.

[0147] In the rotary compressor 10 of the first embodiment, the index value indicating the easiness of bending of the main shaft portion 26 is 3×10 －4The index value described above is obtained by dividing the sum Vcc of the volumes of the first compression chamber 41s and the second compression chamber 51s by the fourth power of the diameter Φ of the main shaft portion 26 of the drive shaft 25. Thus, during operation of the rotary compressor 10, the main shaft portion 26 can be appropriately flexed to achieve static balance between the first and second eccentric portions 44, 54 and the first and second balance weights 71, 72.

[0148] In the rotary compressor 10 of the first embodiment, the diameter of the main shaft portion 26 of the drive shaft 25 is less than 16 mm, which is relatively small, and the average value of the product of the mass of the first eccentric portion 44 and the second eccentric portion 54 and the eccentric distance is greater than 600, which is relatively large.

[0149] To suppress the vibration of the rotary compressor 10 during high-speed operation caused by the deflection of the drive shaft 25, one approach is to increase the diameter of the main shaft 26 to improve the rigidity of the drive shaft 25, or to reduce the mass and eccentric distance of the first and second eccentric portions 44, 54, and / or reduce the size of the rotor. However, the former approach increases mechanical losses, such as bearing loss, and reduces the efficiency of the rotary compressor 10. Furthermore, the latter approach limits the capacity of the rotary compressor 10.

[0150] In contrast, if the diameter of the main shaft portion 26 of the drive shaft 25 is 16 mm or less, mechanical losses such as bearing loss can be reduced, thereby improving the efficiency of the rotary compressor 10. Furthermore, if the average value of the product of the mass of the first eccentric portion 44 and the second eccentric portion 54 and the eccentric distance is 600 or greater, the capacity of the rotary compressor 10 can be relatively large. Consequently, a rotary compressor 10 with low vibration, high efficiency, and high capacity can be realized during high-speed operation.

[0151] In the refrigeration device 1 of the first embodiment, a rotary compressor 10 is used in the refrigerant circuit 1a. The rotary compressor 10 reduces vibration during high-speed operation. Using the rotary compressor 10 in the refrigerant circuit 1a contributes to a low-vibration and low-noise refrigeration cycle.

[0152] (Other Implementation Methods)

[0153] like Figure 13As shown, the compression mechanism 30 of the rotary compressor 10 of the above embodiment can also be constructed as a rolling piston type in which the first blade 47 of the first piston 45 and the first roller portion 46 are formed separately. In this compression mechanism 30, the flat first blade 47 is embedded in the first blade groove 90 extending along the radial direction of the first cylinder 40 in a freely movable manner, and the first bushing 48 is omitted. The first blade 47 is pushed against the outer peripheral surface of the first roller portion 46 by the spring 91. The top end of the first blade 47 is in sliding contact with the outer peripheral surface of the first roller portion 46. These can also be the same in the second piston 55.

[0154] In the rotary compressor 10 of the above embodiment, the mass of the first balancing weight 71 and the mass of the second balancing weight 72 may be the same, or the eccentric distance of the first balancing weight 71 and the eccentric distance of the second balancing weight 72 may be the same. Furthermore, the shape of the first balancing weight 71 and the shape of the second balancing weight 72 may be the same, and any shape may be employed. In short, the product of the mass and eccentric distance of the second balancing weight 72 (m2 × r2) is smaller than the product of the mass and eccentric distance of the first balancing weight 71 (m1 × r1).

[0155] In the rotary compressor 10 of the above embodiment, the mass of the first eccentric portion 44 and the mass of the second eccentric portion 54 may be different from each other, and the eccentric distance of the first eccentric portion 44 and the eccentric distance of the second eccentric portion 54 may be different from each other. In short, as long as the static balance of the entire rotating system including the drive mechanism 20, the compression mechanism 30 and the balancer 70 is achieved during the operation of the rotary compressor 10, it will be sufficient.

[0156] While the embodiments and modifications are described above, it should be understood that various changes may be made to the embodiments and specific circumstances without departing from the spirit and scope of the claims. In addition, the embodiments and modifications may be appropriately combined and replaced as long as they do not affect the functions of the objects disclosed herein.

[0157] Industrial Applicability

[0158] In summary, the present disclosure is useful for a rotary compressor and a refrigeration device including the rotary compressor.

[0159] - Explanation of symbols -

[0160] AC axis

[0161] GC1 Center of gravity of the first balancing weight

[0162] GC2 Center of gravity of the second balance weight

[0163] GC3 Center of gravity of the first eccentric

[0164] GC4 Second eccentric center of gravity

[0165] 1 Refrigeration unit

[0166] 1a Refrigerant circuit

[0167] 10 Rotary compressor

[0168] 21 Electric Motor

[0169] 23 rotor

[0170] 25 drive shaft

[0171] 30 Compression mechanism

[0172] 40 First Cylinder

[0173] 41s First Compression Chamber

[0174] 44 first eccentric part

[0175] 50 Second cylinder

[0176] 51s Second compression chamber

[0177] 54 first eccentric part

[0178] 70 Balancer

[0179] 71 First balance weight

[0180] 72 Second balance weight

Claims

1. A rotary compressor, comprising a compression mechanism (30), a drive shaft (25), an electric motor (21), and a balancer (70), wherein the compression mechanism (30) sucks in and compresses a fluid, the drive shaft (25) drives the compression mechanism (30), the electric motor (21) has a rotor (23) connected to the drive shaft (25), the balancer (70) is arranged on the rotor (23), the compression mechanism (30) has a first cylinder (40) and a second cylinder (50), a first eccentric portion (44), and a second eccentric portion (54), the first cylinder (40) and the second cylinder (50) are arranged in sequence from the rotor (23) side in an axial direction along the axis (AC) of the drive shaft (25), the first eccentric portion (44) is accommodated inside the first cylinder (40), and the second eccentric portion (54) is accommodated inside the second cylinder (54). The balancer (70) is provided inside the cylinder (50), wherein the balancer (70) has a first balancing weight (71) and a second balancing weight (72), wherein the first balancing weight (71) is arranged at one end portion of the rotor (23) on the compression mechanism (30) side in the axial direction, and the second balancing weight (72) is arranged at the other end portion of the rotor (23) in the axial direction, wherein the first eccentric portion (44) and the first balancing weight (71) are eccentric to one side relative to the axis (AC) of the drive shaft (25), and the second eccentric portion (54) and the second balancing weight (72) are eccentric to the other side relative to the axis (AC) of the drive shaft (25), and wherein the first eccentric portion (44) rotates eccentrically inside the first cylinder (40) and the second eccentric portion (54) rotates eccentrically inside the second cylinder (50) in a manner linked to the rotation of the drive shaft (25), and wherein: When the mass of the first balancing weight (71) is set to m1, the eccentric distance between the center of gravity (GC1) of the first balancing weight (71) and the axis (AC) of the drive shaft (25) is set to r1, the mass of the second balancing weight (72) is set to m2, and the eccentric distance between the center of gravity (GC2) of the second balancing weight (72) and the axis (AC) of the drive shaft (25) is set to r2, the following relationship is satisfied: m1×r1>m2×r2.

2. The rotary compressor according to claim 1, wherein: The maximum rotation speed of the drive shaft (25) is above 120 rps.

3. The rotary compressor according to claim 1 or 2, characterized in that: When the mass of the first eccentric portion (44) is set to m3, the eccentric distance between the center of gravity (GC3) of the first eccentric portion (44) and the axis (AC) of the drive shaft (25) is set to r3, the mass of the second eccentric portion (54) is set to m4, the eccentric distance between the center of gravity (GC4) of the second eccentric portion (54) and the axis (AC) of the drive shaft (25) is set to r4, and the maximum rotational speed of the drive shaft (25) is set to Nmax [rps], the following relationship is satisfied: 1.2-0.002×Nmax≤(m2×r2+m4×r4) / (m1×r1+m3×r3)≤0.

98.

4. The rotary compressor according to claim 3, wherein: The following relationship is satisfied: 0.88≤(m2×r2+m4×r4) / (m1×r1+m3×r3).

5. The rotary compressor according to any one of claims 1 to 4, characterized in that: When the sum of the volume of the first compression chamber (41s) formed between the inner circumferential surface of the first cylinder (40) and the first eccentric portion (44) and the volume of the second compression chamber (51s) formed between the inner circumferential surface of the second cylinder (50) and the second eccentric portion (54) is set to Vcc [cc], and the diameter of the main shaft portion (26) of the drive shaft (25) connected to the rotor (23) is set to Φ [mm], the following relationship is satisfied: Vcc / Φ 4 ≥3×10 －4 。 6. The rotary compressor according to any one of claims 1 to 5, characterized in that: The diameter of the main shaft portion (26) of the drive shaft (25) connected to the rotor (23) is 16 mm or less. When the mass of the first eccentric portion (44) is set to m3 [g], the eccentric distance between the center of gravity (GC3) of the first eccentric portion (44) and the axis (AC) of the drive shaft (25) is set to r3 [mm], the mass of the second eccentric portion (54) is set to m4 [g], and the eccentric distance between the center of gravity (GC4) of the second eccentric portion (54) and the axis (AC) of the drive shaft (25) is set to r4 [mm], the following relationship is satisfied: (m3×r3+m4×r4) / 2≥600.

7. A refrigeration device, comprising a refrigerant circuit (1a) for performing a refrigeration cycle, characterized in that: The refrigerant circuit (1a) includes the rotary compressor (10) according to any one of claims 1 to 6.

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