JP3579323B2 - 2-cylinder 2-stage compression rotary compressor - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a two-cylinder two-stage compression rotary compressor, and more particularly to a two-cylinder two-stage compression rotary compressor capable of changing the displacement volume with a simple configuration, for example.
[0002]
[Prior art]
For example, in a two-cylinder rotary compressor in which a rotary compression mechanism is vertically arranged in a closed container, the amount of eccentricity of the rotating shaft in the vertical rotation compression mechanism is the same in the vertical direction. In the two-stage compression rotary compressor, the displacement is changed by changing the amount of eccentricity of an eccentric portion provided on the rotating shaft and the outer diameter of a roller fitted to the eccentric portion and eccentrically rotating in the cylinder. . In this case, the maximum value of the displacement volume is determined by the amount of eccentricity of the rotating shaft, the diameter of the eccentric portion of the rotating shaft, and the diameter of the bearing. In the prior art, even in a two-stage compression rotary compressor, the diameter of the eccentric portion of the rotating shaft and the diameter of the bearing are 1 unit. The stage (lower stage) and the second stage (higher stage) are the same.
[0003]
[Problems to be solved by the invention]
Therefore, when setting the exclusion volume in the two-stage compression rotary compressor, there is a problem that the degree of freedom of the setting is limited, the productivity is low, and the cost is high.
[0004]
SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a two-cylinder two-stage compression rotary compressor which can easily set an excluded volume with a simple configuration.
[0005]
[Means for Solving the Problems]
The present invention has an airtight container, an electric motor unit housed in the airtight container, and two cylinders driven by a rotating shaft of the electric motor unit, and is fitted in each cylinder to an eccentric part provided on the rotating shaft. A rotary compression mechanism that eccentrically rotates the rollers and separates the interior of each cylinder by vanes, sucks, compresses, and discharges the refrigerant gas.This rotary compression mechanism is a low-stage that sucks and compresses low-pressure refrigerant gas. A side compression section, a high-stage compression section that sucks and compresses the refrigerant gas that has been compressed by the low-stage compression section and raised to an intermediate pressure, and a hole that is interposed between the two compression sections and that has a rotary shaft inserted therethrough. In a two-cylinder two-stage compression rotary compressor including an intermediate partition plate, two eccentric portions provided on a rotating shaft have a phase difference of 180 degrees and a shaft diameter of a connecting portion connecting the two eccentric portions to each other. And through the eccentric Characterized in that the shaft diameter of the rotating shaft end portion continuous to the binding portion to both set smaller than the shaft diameter of the rotary shaft, a second cylinder type two-stage compression rotary compressor.
[0006]
[Action]
In a two-cylinder two-stage compression compressor, the eccentric part diameter and bearing diameter (shaft diameter) of two eccentric parts provided on a rotating shaft are changed between a low stage side (first stage) and a high stage side (second stage). This makes it possible to change the excluded volume. For example, this can be achieved by reducing the diameter of the first-stage low-stage bearing and increasing the size of the second-stage high-stage bearing.
[0007]
【The invention's effect】
According to the present invention, the degree of freedom in setting the exclusion volume is improved, and accordingly, it is possible to improve productivity and reduce costs.
[0008]
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.
[0009]
【Example】
As shown in FIG. 1, an internal low-pressure two-cylinder two-stage compression rotary compressor 10 according to an embodiment of the present invention includes a cylindrical hermetic container 12 made of a steel plate, and a motor portion 14 disposed and housed in the internal space of the container 12. And a rotary compression mechanism 18 arranged in a space below the electric motor section 14 and driven by a rotating shaft 16 connected to the electric motor section. The cylindrical airtight container 12 has an oil reservoir at the bottom, and is composed of two members: a container body 12A having an upper surface opening for accommodating the electric motor portion 14 and the rotary compression mechanism portion 16, and a lid 12B for closing the upper surface opening of the container body 12A. A terminal terminal 20 (wiring is omitted) for supplying electric power to the motor unit 14 is attached to the lid 12B.
[0010]
The electric motor unit 14 includes an annular stator 22 attached along the upper inner peripheral surface of the cylindrical airtight container 12, and a rotor 24 arranged with a slight gap inside the stator 22. The rotor 24 is provided with a rotating shaft 16 extending vertically through the center thereof.
[0011]
The stator 22 includes a laminated body 26 in which ring-shaped electromagnetic steel sheets are laminated, and a three-phase stator coil 28 mounted on the laminated body 26. Further, the rotor 24 is also formed of a laminated body 30 of electromagnetic steel sheets, like the stator 22, thereby forming an AC motor. Note that a DC motor in which a permanent magnet is embedded in a rotor can be used instead of the AC motor.
[0012]
The rotary compression mechanism 18 includes an intermediate partition plate 36 having a high-stage compression unit 32, a low-stage compression unit 34, and an insertion hole 36 a through which the rotary shaft 16 is inserted, and the high-stage compression unit 32 includes an intermediate partition plate 36. , And the low-stage-side compression section 34 is disposed below the intermediate partition plate 36.
[0013]
That is, the intermediate partition plate 36, upper and lower cylinders 38, 40 provided on the upper and lower sides of the intermediate partition plate 36, and upper and lower eccentric portions 42, 44 provided on the rotary shaft 16 in the upper and lower cylinders 38, 40 are fitted. The upper and lower rollers 46, 48 which are eccentrically rotated and contact with the upper and lower rollers 46, 48, and the upper and lower vanes 50, which partition the inside of the upper and lower cylinders 38, 40 into a low pressure chamber side 38a, 40a and a high pressure chamber side 38b, 40b, respectively. 52, an upper support frame 54 that also closes the opening surfaces of the upper and lower cylinders 38, 40 and also serves as a high-stage bearing 54a of the rotating shaft 16, and a lower support frame 56 that also serves as a low-stage bearing 56a. Is done.
[0014]
The inner diameter of the low-stage bearing 56a is smaller than the inner diameter of the high-stage bearing 54a. The reason will be described later in detail in relation to the amount of eccentricity of the rotating shaft 16, the upper and lower eccentric parts 42 and 44, and the diameter of each eccentric part.
[0015]
The upper support frame 54 and the lower support frame 56 are integrally formed with suction passages 58 and 60 and muffler chamber / discharge passages 62 and 64 which are communicated with the upper and lower cylinders 38 and 40 as appropriate. Is closed by an upper plate 66 and a lower plate 68. Further, the upper and lower vanes 50 and 52 are reciprocally housed in radial guide grooves 70 and 72 formed in the cylinder walls of the upper and lower cylinders 38 and 40, and always contact the upper and lower rollers 46 and 48 by springs 74 and 76. It is energized as follows.
[0016]
The lower cylinder 40 performs a first-stage (lower-stage) compression action, and the upper cylinder 38 further compresses the refrigerant gas that has been subjected to the first-stage compression by the lower cylinder 40 to a second-stage high pressure. (High stage side) compression action is performed.
[0017]
The elements constituting the rotary compression mechanism 18 are arranged in the order of an upper support frame 54, an upper cylinder 38, an intermediate partition plate 36, a lower cylinder 40 and a lower support frame 56, and an upper plate 66 and a lower plate 68 And are integrally connected using a plurality of mounting bolts 78.
[0018]
Further, a vertical oil hole 80 is formed in the rotation shaft 16 at the center of the shaft, and horizontal oil supply holes 82 and 84 and spiral oil supply grooves 86 and 88 communicating with the oil hole 80 are provided.
[0019]
In this embodiment, for example, carbon dioxide (CO2), which is a natural refrigerant, is used in consideration of the global environment, flammability, toxicity, and the like, and the lubricating oil is, for example, mineral oil (mineral oil). ), Existing oils such as alkylbenzene oil, ether oil and ester oil are used.
[0020]
The upper and lower support frames 54 and 56 are compressed by upper and lower cylinders 38 and 40 via upper and lower refrigerant introduction pipes 90 and 92 for introducing a refrigerant to the upper and lower cylinders 38 and 40 via suction passages 58 and 60. Upper and lower refrigerant discharge pipes 94 and 96 for discharging the discharged refrigerant via the muffler chamber and discharge passages 62 and 64 are connected respectively.
[0021]
Further, refrigerant pipes 98, 100, 102 and 104 are connected to the upper and lower refrigerant introduction pipes 90 and 92 and the upper and lower refrigerant discharge pipes 94 and 96, respectively, and an accumulator 106 is connected between the refrigerant pipes 98 and 104. ing. A mounting base 108 is fixed to the outer bottom of the cylindrical closed container 12 by welding or the like.
[0022]
Meanwhile, the rotating shaft 16 in FIG. 1 is, as shown in FIG. 3, a lower portion of the rotating shaft provided with the lower eccentric portion 44, that is, the upper and lower eccentric portions 42, of the upper and lower eccentric portions 42, 44 in which the upper and lower rollers 46, 48 are fitted. , 44 are connected to each other, the shaft diameter of the connecting portion 110 and the shaft diameter of the lower end portion 112 of the rotary shaft supported by the low-stage bearing 56 a provided on the lower support frame 56 are provided on the upper support frame 54. The diameter is set smaller than the shaft diameter of the rotating shaft 16 that is supported by the high-stage bearing 54a.
[0023]
Assuming that the amount of eccentricity of the lower eccentric portion 44 with respect to the axis of the conventional rotary shaft 16 shown in FIG. 5 is A, as shown in FIG. When the diameter of the upper and lower eccentric portions 42 and 44 is set to be the same diameter by setting the diameter to be smaller than the shaft diameter, the eccentric amount B of the lower eccentric portion 44 with respect to the axis of the rotating shaft 16 is larger than the eccentric amount A in the conventional example. (B> A) As a result, for example, the displacement volume in the lower cylinder 40 on the lower stage side (first stage) can be further increased.
[0024]
In another embodiment according to the present invention shown in FIG. 4, the connecting portion 110 connecting the upper and lower eccentric portions 42 and 44 provided on the rotating shaft 16 and the bearing 56a of the lower support frame 56 are supported by the shaft. The shaft diameter of the lower end portion 112 of the rotating shaft is set smaller than the shaft diameter of the rotating shaft 16 supported by the bearing 54 a of the upper support frame 54, and the diameter D of the lower eccentric portion 44 is smaller than the diameter C of the upper eccentric portion 42. By setting (D <C), the diameter of the insertion hole 36a formed in the intermediate partition plate 36 can be reduced, and as a result, the thickness (wall thickness) of the lower roller 48 fitted to the lower eccentric portion 44 is reduced. Since the size can be increased, the contact area of the seal portion between the lower roller 48 and the intermediate partition plate 36 can be increased, and gas leakage can be reduced. Therefore, compression efficiency and volume efficiency are improved.
[0025]
Here, an outline of the operation of the above-described embodiment will be described with reference to FIGS.
[0026]
First, when electricity is supplied to the stator coil 28 of the electric motor unit 14 via the terminal 20 and the wiring (not shown), the electric motor unit 14 starts and the rotating shaft 16 fixed to the rotor 24 rotates. By this rotation, the upper and lower rollers 46 and 48 fitted to the upper and lower eccentric portions 42 and 44 provided on the rotating shaft 16 eccentrically rotate inside the upper and lower cylinders 38 and 40.
[0027]
Thereby, the refrigerant is sucked from the suction port 118 into the low pressure chamber side 40a of the lower cylinder 40 through the refrigerant pipe 100, the lower refrigerant introduction pipe 92, and the suction passage 60 formed in the lower support frame 56 as shown in FIG. The low-pressure refrigerant gas is compressed in the first stage (lower stage side) by the operation of the lower roller 48 and the lower vane 52, and is discharged from the high pressure chamber side 40 b of the lower cylinder 40 to the discharge port 120 and the lower support frame 56. The air is sent to the accumulator 106 from the silencer chamber discharge passage 64, the lower refrigerant discharge pipe 96, and the refrigerant pipe 104.
[0028]
Next, from the accumulator 106 through the refrigerant pipe 98, the upper refrigerant introduction pipe 90, and the suction passage 58 formed in the upper support frame 54, from the suction port 114 to the low pressure chamber side 38a of the upper cylinder 38 as shown in FIG. The sucked intermediate-pressure refrigerant gas is compressed in the second stage (high-stage side) by the operation of the upper roller 46 and the upper vane 50 to become a high-pressure compressed refrigerant gas. The refrigerant is sent to an external refrigerant circuit (not shown) constituting a refrigeration cycle via the discharge port 116, the discharge passage 62 also serving as a muffling chamber formed in the upper support frame 54, the upper refrigerant discharge pipe 94, and the refrigerant pipe 102. You. Thereafter, the refrigerant gas circulates in the above-described path to exhibit a cooling effect.
[0029]
Further, the lubricating oil (not shown) stored at the bottom of the cylindrical hermetic container 12 due to the rotation of the rotating shaft 16 rises through a vertical oil hole 80 formed at the center of the rotating shaft 16. Are supplied to the bearings and the upper and lower eccentric portions 42 and 44 from the horizontal oil supply holes 82 and 84 and the spiral oil supply grooves 86 and 88, respectively, to maintain smooth rotation.
[0030]
The present invention is not limited to the above embodiment. For example, in each of the above-described embodiments, the two-cylinder two-stage compression rotary compressor 10 in which the rotary shaft 16 is vertically mounted has been described. But it goes without saying that it is good.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an essential part of an internal low-pressure two-cylinder two-stage compression rotary compressor showing an embodiment of the present invention.
FIG. 2 is an illustrative view schematically showing a configuration of each compression unit in FIG. 1;
FIG. 3 is a front view of a rotating shaft including a vertical eccentric portion in FIG. 1;
FIG. 4 is a front view of a rotating shaft showing another embodiment corresponding to FIG. 3;
FIG. 5 is a front view of a conventional rotating shaft corresponding to FIGS. 3 and 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Two cylinder type two stage compression rotary compressor 12 ... Cylindrical hermetic container 14 ... Electric motor part 16 ... Rotating shaft 18 ... Rotary compression mechanism part 32 ... High stage compression part 34 ... Low stage compression part 36 ... Intermediate partition plate 36a ... Insertion holes 42 and 44... Vertical eccentric portion 54a... High-stage bearing (second stage bearing)
56a… Low stage bearing (first stage bearing)
110 ... connecting part 112 ... lower end of rotating shaft

Claims (3)

It has an airtight container, an electric motor unit housed in the airtight container, and two cylinders driven by a rotation shaft of the electric motor unit, and is fitted to an eccentric part provided on the rotation shaft in each of the cylinders. A rotary compression mechanism that eccentrically rotates the rollers and partitions the inside of each cylinder by vanes, sucks, compresses, and discharges the refrigerant gas, wherein the rotary compression mechanism is a low stage that sucks and compresses the low-pressure refrigerant gas. A side compression section, a high-stage compression section that sucks and compresses the refrigerant gas that has been compressed by the low-stage compression section and raised to an intermediate pressure, and a hole that is interposed between the two compression sections and that passes through the rotary shaft. In a two-cylinder two-stage compression rotary compressor including the formed intermediate partition plate,
Two eccentric portions provided on the rotating shaft have a phase difference of 180 degrees, and a shaft diameter of a connecting portion connecting the two eccentric portions to each other, and a rotating shaft connected to the connecting portion via the eccentric portion. A two-cylinder two-stage compression rotary compressor, wherein both end shaft diameters are set smaller than the shaft diameter of the rotary shaft. 2. The two-cylinder two-stage compression rotary compressor according to claim 1, wherein the two eccentric portions have the same diameter. 2. The two-cylinder type according to claim 1, wherein, among the two eccentric portions, a diameter of an eccentric portion between the connecting portion and the end of the rotary shaft is set smaller than a diameter of another eccentric portion. Two-stage compression rotary compressor.

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