JP2003106276A - Two-stage compression type rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-stage compression type rotary compressor in which rotary compression elements are fixed to an inner surface of a sealed vessel without degrading the compression performance or the reliability. SOLUTION: In this two-stage compression type rotary compressor of a carbon dioxide refrigerant forming a two-stage compression mechanism with a discharge side of a low-stage compression element 32 connected in series to an intake side of a high-stage compression element 34, the fitting clearance of components in the low-stage compression element 32 is set to be smaller than that in the high-stage compression element 34.

Description

Detailed Description of the Invention

TECHNICAL FIELD The present invention relates to a two-stage compression rotary compressor.

2. Description of the Related Art Conventionally, various two-stage compression type rotary compressors have been proposed in which an electric element and two rotary compression elements driven by a crankshaft connected to the electric element are arranged and housed in a closed container. . Specifically, as shown in FIG. 4, the drive motor 100 is installed in the upper part of the closed container 1003.
5 is connected to the rotary shaft 1005c of the drive motor 1005 in the lower part, and is formed in two stages of upper and lower sides (the upper part is the low pressure compression mechanism 1007, the lower part is the high pressure compression mechanism 100).
9), an oil reservoir is arranged at the bottom, and a low pressure compression mechanism 1007,
Each cylinder 1007c (100
The back surface of the vane (not shown) that divides 9c) into the suction chamber and the compression chamber communicates with the internal space of the closed container 1003, and the back pressure biasing force to the vane is applied to the reaction force of the spring device and the closed container 1003. Formed with pressure. Then, the refrigerant gas discharged from the low-pressure compression mechanism 1007 is introduced into the high-pressure compression mechanism 1009 via the discharge pipe 1007e and the communication pipe 1009d. The discharge refrigerant gas recompressed by the high-pressure compression mechanism 1009 is discharged into the closed container 1003 via the discharge pipe 1009e, and after the inside pressure of the closed container 1003 is increased to high, the discharge pipe provided above the closed container 1003. 1009e '
To an external condenser (not shown) through the expansion valve, a gas-liquid separator, and an evaporator (not shown) in order,
It returns to the low pressure compression mechanism 1007 again through the suction pipe 1007d to realize the vapor compression refrigeration cycle. In the above-described conventional apparatus, the pressure inside the closed container becomes a high pressure substantially equal to the discharge pressure of the high pressure compression mechanism 1009, so that the high pressure gas inside the closed container 1003 leaks into the low pressure compression mechanism 1007 having a large pressure difference. Was there. Further, generally, the intake efficiency of the first-stage low-pressure compression mechanism 1007 has a great influence on the volumetric efficiency of the entire compressor, and therefore there is a risk that the volumetric efficiency and the compression efficiency will decrease due to the high-pressure gas leak to the low-pressure compression mechanism 1007 described above. there were.

As a countermeasure against this, when the internal high pressure is set in the closed container 1003, the fitting clearance between the components in the low pressure compression mechanism 1007 is
The low pressure compression mechanism 1007 is set to be smaller than the fitting clearance between the components of the high pressure compression mechanism 1009.
A configuration is conceivable in which the amount of gas leaking into the cylinder 1007c chamber is reduced. On the other hand, in the above-mentioned conventional apparatus, in order to fix the rotary compression mechanism to the inner surface of the closed container 1003, for example, the cylinder 1007c (1009c) is tack-welded to the closed container 1003. However, in general, the stress caused by such welding causes the welded cylinder 1007c (1
There was a possibility that the inner diameter of 009c) or the sliding groove on which the vane slides would be distorted. Therefore, as described above, the low pressure compression mechanism 10
The fitting clearance between the components in 07 is set to be smaller than the fitting clearance between the components in the high-pressure compression mechanism 1009, and the rotary compression mechanism is closed.
When the cylinder 1007c of the low-pressure compression mechanism 1007 having a small fitting clearance is tack-welded when it is fixed to No. 03, proper fitting clearances between the components are not formed, and in the worst case, the compressor is locked. There was a risk of doing it. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a two-stage compression rotary compressor in which a rotary compression element is fixed to the inner surface of a closed container without degrading compression performance and reliability. And

According to the present invention, an electric element and a rotary compression element driven by a drive shaft connected to the electric element are arranged inside a sealed container, and the rotary compression element is a roller. A lower stage compression element and a higher stage compression element in which cylinders containing a vane and a vane are respectively arranged via an intermediate partition plate, and an upper portion that closes the opening surface of each compression element and also serves as a bearing portion of the drive shaft. A support member and a lower support member,
A two-stage compression mechanism that forms a two-stage compression mechanism in which the discharge side of the low-stage compression element and the suction side of the high-stage compression element are connected in series and uses carbon dioxide as a refrigerant to compress the refrigerant to a supercritical pressure. In the rotary compressor, the fitting clearance between the components of the low-stage compression element is set to be smaller than the fitting clearance between the components of the high-stage compression element. By using this configuration, it is possible to reduce the leakage of high-pressure gas in the closed container into the low-stage compression element having a large pressure difference, and it is possible that the fitting clearance changes due to welding of the cylinder of the high-stage compression element or the like. However, the compressor never locks up. In addition, a drive shaft that revolves the roller in the cylinder may be provided, and the roller may be configured as a non-rotating type that does not rotate with the drive shaft. Specifically, while the vane is projected on the outer peripheral cylindrical surface of the roller,
The roller may be configured to be a non-rotating type by engaging the projecting tip side of the vane with an oscillating body that rotatably supports the outside of the cylinder chamber so as to freely move back and forth. By using this configuration, the same effect can be expected in an oscillating rotary compressor in which vanes and rollers are integrated. Further, the refrigerant compressed by the high-stage compression element may be discharged into the closed container so that the inside of the closed container has an internal high pressure.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings shown below. FIG. 1 is a longitudinal sectional view of a main part of an internal high pressure type two-stage compression rotary compressor which is an embodiment of the present invention. In FIG.
Two-stage compression rotary compressor 10 of the present embodiment
Is a cylindrical closed container 12 made of steel plate, and this closed container 1
Drive motor 14 as an electric element arranged in the upper space of 2 and a compression element driven by a crank shaft (drive shaft) 16 arranged in the lower space of electric motor 14 and connected to this electric motor 14. A rotary compression mechanism 18 is included. The closed container 12 has an oil reservoir at the bottom and is composed of two members, 12A for housing the electric motor 14 and the rotary compression mechanism 18, and a lid 12B for sealing the upper opening of the container body 12A. Is equipped with a terminal terminal (power supply wiring is omitted) 20 for supplying external electric power to the electric motor 14. The electric motor 14 includes a stator 22 mounted in an annular shape along the inner circumference of the upper space of the closed container 12.
And a rotor 24 disposed inside the stator 22 with a slight gap. The rotor 24 is integrally provided with a crankshaft 16 that extends vertically through the center of the rotor 24. The stator 22 has a laminated body 26 in which ring-shaped electromagnetic steel sheets are laminated, and a plurality of coils 28 wound around the laminated body 26. Further, the rotor 24 is also composed of a laminated body 30 of electromagnetic steel plates, like the stator 22. Although an AC motor is used as the electric motor 14 in the present embodiment, a permanent magnet may be embedded to form a DC motor. The rotary compression mechanism 18 includes the low-stage compression element 3
2 and high-stage compression element 34. That is, the intermediate partition plate 3
6, upper and lower cylinders 38 and 40 provided above and below the intermediate partition plate 36, and an upper and lower roller 46 that rotates by connecting the insides of the upper and lower cylinders 38 and 40 to the vertical eccentric portions 42 and 44 provided on the crankshaft 16. , 48 and the upper and lower rollers 4
The upper and lower vanes 50 and 52, which contact the upper and lower cylinders 38 and 40 by contacting the upper and lower cylinders 38 and 40, are divided into suction chambers (suction side) and compression chambers (discharge side), and the opening surfaces of the upper and lower cylinders 38 and 40 are closed. The crankshaft 16 is composed of an upper support member 54 and a lower support member 56 that also serve as the bearings of the crankshaft 16. Further, the upper support member 54 and the lower support member 56 are provided with discharge muffling chambers 58, 60 which are in proper communication with the upper and lower cylinders 38, 40 via a valve device (not shown), and these discharge muffling chambers, etc. The opening is closed by an upper plate 62 and a lower plate 64. Also, the upper and lower vanes 50, 52
Is slidably arranged in radial guide grooves 66, 68 formed in the cylinder walls of the upper and lower cylinders 38, 40, and is urged by springs 70, 72 so as to always contact the upper and lower rollers 46, 48. ing. Then, the lower cylinder 40 performs the first-stage (lower-stage side) compression action, and the upper cylinder 38 performs the second-stage (higher-stage side) compression action for further compressing the refrigerant gas compressed by the lower cylinder 40. Done.
The upper support member 54, the upper cylinder 38, the intermediate partition plate 36, the lower cylinder 40, and the lower support member 56 that constitute the rotary compression mechanism 18 are arranged in this order and together with the upper plate 62 and the lower plate 64, a plurality of them. It is connected and fixed using a mounting bolt 74. Further, a straight oil hole 76 is formed in the crankshaft 16 at the center of the shaft, and spiral oil supply grooves 82, 84 which are continuous with the hole 76 via lateral oil supply holes 78, 80 are formed on the outer peripheral surface of the crankshaft 16 to form bearings and respective bearings. Oil is supplied to the sliding parts. In this embodiment, R404A is used as the refrigerant, and the oil used as the lubricating oil is, for example, mineral oil (mineral oil), alkylbenzene oil, PAG oil (polyalkylene glycol-based oil), ether oil, ester oil, etc. Oil is used. The rotary compression mechanism 18 described above.
In the low-stage compression element 32, the suction side refrigerant pressure is 0.05M.
Pa and the discharge side refrigerant pressure is 0.18 MPa.
Then, in the high-stage compression element 34, the suction side refrigerant pressure is 0.
It is 18 MPa and the discharge side refrigerant pressure is 1.90 MPa. Further, the upper and lower cylinders 38, 40 are provided with upper and lower refrigerant suction passages (not shown) for introducing a refrigerant and a refrigerant discharge passage 86 for discharging the compressed refrigerant via the discharge muffling chambers 58, 60. ing. Then, in each of the refrigerant suction passages and the refrigerant discharge passages 86, refrigerant pipes 98, 10 are provided via connection pipes 90, 92, 94 fixed to the closed container 12.
0 and 102 are connected. A suction muffler 106 that acts as a gas-liquid separator is connected between the refrigerant pipes 100 and 102. Further, the upper plate 62 is provided with a discharge pipe 108 which establishes communication between the discharge muffling chamber 58 of the upper support member 54 and the internal space of the closed container 12, and the discharge pipe 108 of the second stage (high stage compression element 34) is provided. The compressed refrigerant gas is directly discharged into the closed container 12 to make the closed container 12 have a high internal pressure, and then an external condenser (via a connection pipe 96 and a refrigerant pipe 104 fixed to the lid 12B above the closed container 12 ( (Not shown), expansion valve, gas-liquid separator,
The vapor compression refrigeration cycle is realized by returning to the low-stage compression element 32 again through the refrigerant pipe 98, the connecting pipe 90, and the upper refrigerant suction passage of the upper cylinder 38 via an evaporator (not shown) in order. Further, the fitting clearance between the constituent parts of the low-stage compression element 32 is set smaller than the fitting clearance between the constituent parts of the high-stage compression element 34. Specifically, the fitting clearance between the components in the low-stage compression element 32 is set to 10 μm, and the fitting clearance between the components in the high-stage compression element 34 is set to 20 μm.
It is set to μm. As a result, the high-pressure gas in the closed container 12 can be prevented from leaking into the low-stage compression element 32 having a large pressure difference, and the volume efficiency and the compression efficiency can be improved. Further, the upper cylinder 38 of the high-stage compression element 34 is fixed to the inner surface of the closed container 12 by tack welding. Even if the fitting clearance is distorted by the welding of the upper cylinder 38, the fitting lock between the components of the high-stage compression element 34 is set to be relatively large as described above, so that the compressor is locked. There is no such thing. Next, an outline of the operation of the above-described two-stage compression rotary compressor 10 shown in FIG. 1 will be described.
First, when power is supplied to the coil 28 of the electric motor 14 through the terminal terminal 20 and the power supply wiring (not shown), the rotor 2
4 rotates and the crankshaft 16 fixed to it rotates. By this rotation, the upper and lower rollers 46 connected to the upper and lower eccentric parts 42 and 44 integrally provided with the crankshaft 16,
48 rotates eccentrically in the upper and lower cylinders 38, 40. As a result, the refrigerant gas sucked into the suction chamber 40a of the lower cylinder 40 from the suction port 118 through the refrigerant pipe 98 and the refrigerant suction passage (not shown) as shown in FIG. The operation of the vane 52 causes the first stage compression. The intermediate-pressure refrigerant gas discharged from the compression chamber 40b to the discharge muffling chamber 60 of the lower support member 56 via the discharge port 120 is delivered to the refrigerant pipe 100 through the refrigerant discharge passage 88 of the lower cylinder 40. . Next, the refrigerant gas from the refrigerant pipe 100 is sucked into the low pressure chamber 38a of the upper cylinder 38 from the suction port 114 shown in FIG. 2 via the suction muffler 106, the refrigerant pipe 102 and the refrigerant suction passage (not shown). The intermediate pressure refrigerant gas is
The second roller is compressed by the operation of the upper roller 46 and the upper vane 50. Then, the high-pressure refrigerant gas discharged from the compression chamber 38 b of the upper cylinder 38 into the discharge muffling chamber 58 of the upper support member 54 via the discharge port 116 is discharged to the discharge muffling chamber 5.
8 through the discharge pipe 108 and the refrigerant pipe 104 to be delivered to an external refrigerant circuit (not shown) that constitutes a vapor compression refrigeration cycle. After that, the suction, compression, and discharge of the refrigerant gas are performed by the same route. Further, due to the rotation of the crankshaft 16, the lubricating oil stored in the bottom portion of the closed container 12 has a vertical oil hole 7 formed in the axial center of the crankshaft 16.
6 is lifted up and horizontal oil supply holes 78 and 80 are provided in the middle thereof.
It flows out to the spiral oil supply grooves 82, 84 formed on the outer peripheral surface. As a result, the bearing of the crankshaft 16 and the upper and lower rollers 46, 48 and the sliding parts of the upper and lower eccentric parts 42, 44 are satisfactorily lubricated, and as a result, the crankshaft 16 and the upper and lower eccentric parts 42, 44 are made smooth. The rotation can be performed. The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. Further, it goes without saying that the configuration of each part of the present invention is not limited to the above-described embodiment, and various modifications can be made within the technical scope described in the claims. For example, in the above-described embodiment, the case where the vane is supported in the cylinder so as to be able to move forward and backward and a back pressure is applied to bring the tip of the vane into contact with the outer peripheral surface of the roller, and the vane and the roller are relatively moved has been described. However, the present invention is not limited to this configuration, and as shown in FIG.
Is integrally provided so as to project outward in the radial direction of the cylinder 303, and the suction port 304 and the discharge port 3 in the cylinder 303 are provided.
Circular holding hole 3 such as a cylinder or a sphere in the inner part of the middle of 05
No. 06 is provided, and the holding body 306 has a receiving groove 308a whose one end is opened to the cylinder chamber 307 side.
8 is rotatably held and the receiving groove 308 of the support 308 is held.
The tip end of the vane 301 on the protruding side is slidably inserted into a. Then, the roller 302 is configured as a non-rotating type that does not rotate with the crank shaft 309 that is a drive shaft,
The roller 302 is revolved in the cylinder 303 by driving the crankshaft 309. Here, when the vane 301 is provided on a part of the outer periphery of the roller 302, the roller 30
By forming a mounting groove into which the base end part of the vane 301 can be inserted on the 2 side, and inserting the base end part of the vane 301 into this mounting groove and bonding and integrating with an adhesive, or by brazing It is integrated. Further, in the above embodiment example,
Although the case where the high-stage compression element is fixed to the inner surface of the closed container by tack welding has been described, the present invention is not limited to this, and it may be fixed by another welding method such as arc spot welding or TIG welding. Further, it is not limited to welding and may be fixed by press fitting, shrink fitting, or the like. Further, in the above-described embodiment, the case where R404A is used as the refrigerant has been described, but other refrigerants may be used, for example, carbon dioxide may be used as the refrigerant and compressed to the supercritical pressure. In this case, there is little impact on the environment,
In addition, it is possible to realize a refrigeration cycle that is neither flammable nor toxic.

As described above, according to the present invention, it is possible to prevent the high-pressure gas in the closed container from leaking into the low-stage compression element having a large pressure difference, and to improve the volume efficiency and the compression efficiency. . Further, even if the fitting clearance between the components of the high-stage compression element changes due to welding or the like, the compressor will not be locked.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part of an internal high pressure type two-stage compression rotary compressor which is an embodiment of the present invention.

FIG. 2 is a schematic plan view showing a main configuration of each compression element in FIG.

FIG. 3 is a schematic plan view showing a configuration of a main part of each compression element of an internal high pressure type two-stage compression rotary compressor which is another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a main part of a conventional two-stage compression rotary compressor.

[Explanation of symbols]

10 Internal high pressure type two-stage compression rotary compressor 12 Cylindrical closed container 14 Drive motor (electric element) 16 crankshaft 18 Rotary compression mechanism (rotary compression element) 32 Low-stage compression element 34 High-stage compression element 36 Intermediate partition plate 38, 40 Vertical cylinder 42,44 Vertical eccentric part 46, 48 upper and lower rollers 50, 52 upper and lower vanes 54 Upper support member 56 Lower support member 82, 84 oil groove

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshiyuki Ehara             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Takashi Yamakawa, inventor             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. F-term (reference) 3H029 AA04 AA09 AA13 AB03 AB05                       AB08 BB16 BB33 BB43 BB44                       CC03 CC05

Claims (4)

[Claims] 1. An electric element and a rotary compression element driven by a drive shaft connected to the electric element are arranged inside a hermetic container, and the rotary compression element includes a cylinder containing rollers and vanes. A low-stage compression element and a high-stage compression element which are respectively arranged via an intermediate partition plate, and an upper support member and a lower support member which close the opening surfaces of the respective compression elements and also serve as the bearing portion of the drive shaft. A two-stage compression mechanism is provided in which the discharge side of the low-stage compression element and the suction side of the high-stage compression element are connected in series, and carbon dioxide is used as a refrigerant to compress the refrigerant to a supercritical pressure. In the stage compression rotary compressor, the fitting clearance between the components of the low-stage compression element is set to be smaller than the fitting clearance of the components in the high-stage compression element. 2
Stage compression rotary compressor. 2. A two-stage compression type rotary compressor according to claim 1, further comprising a drive shaft for revolving the roller in the cylinder, wherein the roller is a non-rotating type that does not rotate with the drive shaft. 3. A vane is provided on a cylindrical surface of an outer peripheral portion of the roller, and a protruding tip end side of the vane is engaged with an oscillating body for rotatably supporting an outside of a cylinder chamber so as to move back and forth. The two-stage compression rotary compressor according to claim 2, wherein the roller is configured to be non-rotating. 4. The refrigerant compressed by the high-stage compression element is discharged to the inside of the hermetically sealed container so that the inside of the hermetically sealed container has an internal high pressure. Two-stage compression rotary compressor.