JP2003328972A - Hermetic two-cylinder rotary compressor and manufacturing method thereof - Google Patents

Abstract

(57) Abstract: In a hermetically sealed two-cylinder rotary compressor, it can be manufactured at low cost while ensuring the reliability of a crankshaft, and can increase an amount of pushing or a roller without increasing the overall size of the compressor. Increase the capacity or efficiency of the compressor by increasing the seal length at the end face. The two compression elements of a compression mechanism section are two eccentric sections having a phase difference of 180 degrees of a crankshaft.
Driving at 52A, the outer diameter of the sub-bearing insertion portion 56 inserted into the sub-bearing 11 is made smaller than the outer diameter of the main bearing insertion portion 51 inserted into the main bearing 7, and the two eccentric portions 52, 52A The outer peripheral surface on the eccentric shaft side is recessed from the outer peripheral surface of the main bearing insertion portion 51, and a connecting portion 53 connecting the two eccentric portions 52, 52 </ b> A is provided with a portion 54 having a smaller diameter than the outer diameter of the main bearing insertion portion 51. The axial length of the small diameter portion 54 is set to be equal to or greater than the height of the roller 52 on the main bearing side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic two-cylinder rotary compressor having two cylinders in a compression mechanism and a method for manufacturing the same, and in particular, a hermetic seal used in a refrigerator such as an air conditioner or a cold air application product. It is suitable for a type 2 cylinder rotary compressor and a manufacturing method thereof.

[0002]

2. Description of the Related Art A hermetic two-cylinder rotary compressor is widely adopted as a compact, highly efficient, low vibration compression system.

As a conventional hermetic two-cylinder rotary compressor, a compression mechanism portion is provided in a hermetically sealed container and connected to the electric motor portion by a crankshaft provided with an electric motor portion and two eccentric portions having a phase difference of 180 degrees. And the compression mechanism portion includes two compression elements, each of which constitutes two compression elements.
The individual cylinders are connected via a partition plate, and two compression chambers are formed by the cylinder, the partition plate, and a main bearing that supports the crankshaft and a sub-bearing that includes a closing portion that closes the cylinder. A roller fitted to the eccentric portion is eccentrically rotated in these two compression chambers to perform a compression action, and an outer diameter of a sub bearing fitting portion fitted to the sub bearing is fitted to the main bearing. The outer diameter of the eccentric part on the side of the sub-bearing is made smaller than the outer diameter of the eccentric part on the side of the sub-bearing to be the same as the outer diameter of the sub-bearing. The outer diameter of the main bearing is smaller than the outer diameter of the main bearing fitting portion, and the outer diameter of the eccentric portion on the main bearing side on the side opposite to the eccentric shaft is fitted into the main bearing. The same west to the outer diameter of the join the club, it is the axial length of connecting portion for connecting the two eccentric portions that smaller than the height of the two rollers.

In this prior art, after forming the crankshaft, the roller on the auxiliary bearing side is inserted from the auxiliary bearing side and fitted into the eccentric part on the auxiliary bearing side, and the roller on the main bearing side is inserted on the main bearing side. It is inserted from the bottom to fit into the eccentric part on the main bearing side.

In the related art, the outer diameter of the sub bearing fitting portion is made smaller than the outer diameter of the main bearing fitting portion, and the outer diameter of the eccentric portion on the side of the sub bearing on the side opposite to the eccentric shaft is outside the main bearing fitting portion. Since the diameter is smaller than the diameter, the compression element on the sub bearing side can make the eccentric amount of the eccentric portion larger than that on the main bearing side. As a result, if the seal length of the roller is not changed, the pushing amount of the compression element (in other words, the cylinder volume) can be increased, and the compression capacity (in other words, the refrigeration capacity) can be increased. . If the seal length of the roller (in other words, the seal length between the low pressure part and the high pressure part) is increased instead of increasing the pushing amount, the leakage of the working fluid from the high pressure side to the low pressure side will occur. And the efficiency of the compressor can be improved.

Documents related to this prior art include Japanese Patent Laid-Open Nos. 5-10279 and 2001-2717.
No. 73 publication is cited.

[0007]

However, in the above-mentioned prior art, the outer diameter of the eccentric portion on the main bearing side on the side opposite to the eccentric shaft is the same as the outer diameter of the main bearing fitting portion, and the two eccentric portions are connected. Since the axial length of the connecting portion is smaller than the height of the two rollers, the eccentric amount of the eccentric portion of the compression element on the main bearing side cannot be easily increased, and the compression element on the main bearing side cannot be increased. However, there is a problem that it is difficult to increase the compression capacity or improve the efficiency.

For example, in the related art, the pushing amount can be increased by a simple structure change in which the outer diameter of the eccentric part on the main bearing side on the side opposite to the eccentric shaft is smaller than the outer diameter of the main bearing fitting part. Although it is conceivable, there is a problem that even if this is done, the roller on the main bearing side cannot be inserted from either side of the main bearing side or the sub bearing side. That is, if the roller on the main bearing side is also inserted from the main bearing side, when the roller is moved from the main bearing fitting portion to the eccentric portion, the lower end surface of the roller comes into contact with the upper surface of the eccentric portion. However, if the roller is moved from the eccentric part on the sub bearing side to the eccentric part on the main bearing side, the upper end surface of the roller cannot be inserted. The eccentric portion comes into contact with the lower surface and cannot be inserted.

Therefore, in the prior art, it is conceivable to reduce the diameter of the entire crankshaft including the main bearing fitting portion. However, if such a change is made, the strength required for the crankshaft cannot be obtained and the reliability is lowered. There was a problem to do. Further, in the prior art, it is conceivable to enlarge the cylinder in the compression element on the main bearing side in order to increase the amount of pushing. However, by making such a change, the size of the entire compressor increases and A large number of parts (for example, other compression elements, electric motor parts, hermetically sealed containers, etc.) have to be changed in accordance with the change, which causes a problem of increasing cost.

It is an object of the present invention to secure the reliability of the crankshaft, to manufacture it at a low cost with a minimum change, and to increase the pushing amount or to increase the roller end surface without increasing the overall size of the compressor. The seal length can be increased,
It is an object of the present invention to provide a hermetically sealed two-cylinder rotary compressor capable of improving the capacity or efficiency of the compressor and a manufacturing method thereof.

[0011]

A hermetic two-cylinder rotary compressor of the present invention for achieving the above-mentioned object is provided with an electric motor part and two eccentric parts having a phase difference of 180 degrees in a hermetic container. And a compression mechanism portion connected to the electric motor portion by a crankshaft, the compression mechanism portion includes two compression elements, and two cylinders forming each compression element are connected via a partition plate, A main bearing and a sub bearing for supporting the crankshaft, which are provided with a cylinder, the partition plate, and a closing portion that closes the cylinder, form two compression chambers, and these two compression chambers are fitted to the eccentric portion. The roller is eccentrically rotated so as to perform a compressing action, and the outer peripheral surface of the two eccentric portions on the side opposite to the eccentric shaft is recessed from the outer peripheral surface of the main bearing fitting portion, so that the two eccentric portions can be positioned. The outer diameter on the side opposite to the eccentric shaft is made smaller than the outer diameter of the main bearing fitting portion, and the connecting portion connecting the two eccentric portions is provided with a portion having a smaller diameter than the outer diameter of the main bearing fitting portion, and the small diameter thereof. The length of the portion in the axial direction is set to be equal to or greater than the height of the roller on the main bearing side.

In the method for manufacturing a hermetic two-cylinder rotary compressor according to the present invention for achieving the above object, the crankshaft is fitted with the outer diameter of a sub-bearing fitting portion fitted into the sub-bearing into the main bearing. Is smaller than the outer diameter of the main bearing fitting portion, and the outer diameter of the two eccentric portions on the side opposite to the eccentric shaft is smaller than the outer diameter of the main bearing fitting portion fitted into the main bearing. A portion having a diameter smaller than the outer diameter of the main bearing fitting portion is provided in the connecting portion that connects the eccentric portion, and the axial length of the small diameter portion is formed to be equal to or greater than the height of the roller on the main bearing side. Insert the roller on the bearing side from the sub bearing side of the crankshaft, and further pass through the eccentric portion on the sub bearing side and the connecting portion in order to fit the eccentric portion on the main bearing side. Lies in the fact was.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A plurality of embodiments of a hermetic two-cylinder rotary compressor of the present invention will be described below with reference to the drawings.
The same reference numerals in the drawings of each embodiment indicate the same or equivalent components.

First, a hermetically sealed two-cylinder rotary compressor according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5.
1 is a vertical sectional view showing a hermetic two-cylinder rotary compressor of a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a hermetic two-cylinder rotary compressor of FIG. Assembly process diagram of the crankshaft and rotor used, FIG. 4 is BB of FIG.
FIG. 5 is a sectional view, and FIG. 5 is an assembly process diagram of the modified example of FIG.

The closed type two-cylinder rotary compressor 20 is
It is provided with a compressor body 30 and a gas-liquid separator 2. The hermetic two-cylinder rotary compressor 20 constitutes a part of a refrigeration cycle in a refrigerator such as an air conditioner or a cold air application product. As the refrigerant, an HFC-based refrigerant (for example, HFC-based) that is more environmentally friendly than an HCFC-based refrigerant is used.
410A refrigerant) and natural refrigerants are used.

The compressor body 30 is constructed by accommodating an electric motor section 21 and a compression mechanism section 22 in a closed container 1. The electric motor section 21 and the compression mechanism section 22 are connected via the crankshaft 5. The electric motor section 21 is configured to include the stator 3 and the rotor 4. The stator 3 is fixed to the container tubular member 1b by shrink fitting, and the rotor 4 is fixed to the crankshaft 7
It is fixed by press fitting etc. Balance weights 27 are attached to the upper and lower ends of the rotor 4.

The closed container 1 comprises a container lower member 1a, a container cylinder member 1b and a container upper member 1c. The container upper member 1c and the container lower member 1a are fitted to the container tubular member 1b, and the fitting portions are welded to seal the inside. The container cylinder member 1b is formed of an iron plate in a cylindrical shape having upper and lower openings.

The compression mechanism 22 includes a main bearing 7, a crankshaft 5, a sub bearing 11, two cylinders 8 and 8A, two rollers 9 and 9a, two vanes 17,
And one partition plate 10 as a main component. The compression mechanism 22 includes cylinders 8 and 8A, rollers 9 and 9a, and vanes 17 arranged on both sides of the partition plate 10, and the main bearing 7 and the sub-bearing 1 are provided outside them.
1 has two compression elements configured by being arranged. In this way, the partition plate 10 is shared by being sandwiched between the two compression elements.

The compression chamber of one compression element (compression element on the main bearing side) is constituted by the partition plate 10, the cylinder 8, the main bearing 7, and the roller 9, and the compression chamber of the other compression element (compression element on the sub bearing side). Partition plate 1 in the compression chamber
0, cylinder 8A, sub bearing 11, and roller 9A
It is composed by.

The main bearing 7 is the container cylinder member 1b.
The main bearing fitting portion 51 of the crankshaft 5 is rotatably fitted in the main bearing 7. The eccentric two eccentric parts having a phase difference of 180 degrees are formed on the crankshaft 7, and the rollers 9 and 9A are rotatably fitted to the two eccentric parts. The cylinder 8 and the partition plate 10 are fixed to the main bearing 7 with bolts 6, and the cylinder 8A and the partition plate 10 are fixed to the sub bearing 11 with bolts 6A. A sub bearing fitting portion 56 on the tip side of the crankshaft 7 is rotatably fitted in the sub bearing 11. In this way, the two compression elements are
Thus, it is fixed to the closed container 1.

The crankshaft 5 has an auxiliary bearing fitting portion 56.
The outer diameter D ₁ is smaller than the outer diameter D ₂ of the main bearing fitting portion 51. In other words, the main bearing fitting portion 51
The outer diameter D ₁ of the sub-bearing fitting portion 56 is larger than the outer diameter D ₁ . As a result, the required strength of the crankshaft 5 can be obtained and the reliability can be ensured.

The crankshaft 5 has two eccentric parts 5
The outer peripheral surface on the side opposite to the eccentric shaft in 2, 52A is recessed by a dimension δ (see FIG. 3) from the outer peripheral surface of the main bearing fitting portion 51. The connecting portion 53 that connects the two eccentric portions 52 and 52A is provided with a portion 54 having a diameter smaller than the outer diameter of the main bearing fitting portion 51, and the axial length L _{2 of the} small diameter portion 54 is closer to the main bearing side. The height of the roller 9 is set to be equal to or higher than L ₁ . The strength required on the side of the main bearing fitting portion 51 with respect to the sub bearing may be smaller than the strength required on the side of the main bearing fitting portion 51, and the strength of the sub bearing fitting portion 56, the eccentric portion 52A, the connecting portion 53, and the eccentric portion. Even if the outer diameter of 52 is reduced, its reliability can be ensured, and the eccentricity can be set larger by reducing the diameter of the sub bearing fitting portion side until the strength is allowed. You can increase your ability.

The roller 9 on the main bearing side is a crankshaft.
5 is inserted from the sub bearing fitting portion 56 side,
As shown in (a), through the sub bearing fitting portion 56
It is fitted to the eccentric part 52A on the sub bearing side, and
As shown in FIG. 3B, after passing through the small diameter portion 54,
As shown in (c), the axial length of the small diameter portion 54.
L _TwoIs the height L of the roller 9₁That is set above
Is used to move laterally within the small diameter portion 54,
In addition, as shown in FIG.
Assembled by fitting to the eccentric part 52 on the aligning side.
To be

Further, in the crankshaft 5, between the small-diameter portion 54 and the eccentric portions 52, 52A of the connecting portion 53, an arc-shaped large-diameter portion having a larger diameter than the small-diameter portion 54 and concentric with the main bearing fitting portion 51. 55 and 55A are integrally formed. By integrally forming the large-diameter portions 55 and 55A in this way, the thickness of the eccentric portions 52 and 52A is reduced to secure the strength of the crankshaft 5 in the compression element portion and the eccentric portions 52 and 52A. Friction with the inner surfaces of the rollers 9 and 9A can be reduced, and efficiency can be improved.

Here, a modified example of the crankshaft 5 shown in FIG. 5 will be described. The crankshaft 5 of this modification is shown in FIG.
Compared with the one shown in FIG. 5, the large diameter portion 55 is provided only between the small diameter portion 54 and the eccentric portion 52, and the small diameter portion 54 and the eccentric portion 52A are provided.
The large diameter portion 55A is not provided between
The difference is that the axial thickness of the large diameter portion 55 is increased by the amount that the large diameter portion 55A is not provided. The axial length of the small diameter portion 54 of the crankshaft 5 of this modified example is the same as the axial length of the small diameter portion 54 of FIG. The method of assembling the roller 9 to the crankshaft 5 in this modification is basically the same as that shown in FIGS. 3A to 3D, as shown in FIGS. The description is omitted.

The crankshaft 5 of this modified example has a small-diameter portion 5
4 and a large-diameter portion 5 only between the eccentric portion 52 on the main bearing side.
5, the small diameter portion 54 and the eccentric portion 52 on the auxiliary bearing side
Since the large diameter portion 55A is not provided between the large diameter portion 55A and A, the axial thickness of the large diameter portion 55 can be increased as much as the large diameter portion 55A is not provided. It is possible to increase the strength of the crankshaft 5 and improve the reliability thereof, while exerting various effects.

The vane 1 is placed in the vane groove of the cylinders 8 and 8A.
7 is slidably fitted (see FIG. 2). Vane 1
7 is pressed by a spring 18 to divide each compression chamber into a low pressure chamber 25 and a high pressure chamber 26. The pressing force of the spring 18 is set to a force that balances the inertial force caused by the reciprocating motion of the rollers 9 and 9A. A cylinder suction port 14 is provided in each low pressure chamber 25. In this embodiment, the rollers 9 and 9A and the vane 1 are
However, the present invention is also applicable to a swing piston type in which a roller and a vane are integrated.

Returning to FIG. 1 to FIG. 4, the partition plate 10 is formed with one suction passage 12 extending from the side opening to the center. Further, the partition plate 10 has a suction passage 12
A communication hole 13 is formed to branch to both sides to reach the cylinder suction port 14 of the suction chamber 25 of each compression element. Since this communication hole 13 is formed perpendicularly to the partition plate 10,
Its formation can be carried out very easily. The suction passage 12 and the communication hole 13 form a refrigerant flow path in the partition plate 10, and the flow paths are vertically symmetrical.

In order to increase the flow passage cross-sectional area of the suction passage 12, the partition plate 10 is formed to be thicker than at least the cylinder 8 and, in this embodiment, thicker than the cylinder 8A. Particularly, in this embodiment, the partition plate 10 is formed to have a thickness of 1.25 times or more the thickness of the cylinders 8 and 8A.

As described above, when the thickness of the partition plate 10 is increased, the whirling of the compression mechanism portion 22 becomes large. Therefore, the balance weight 27 having a size corresponding to this is attached to the upper and lower end portions of the rotor 4. There is.

The gas-liquid separator 2 is fixed to the side surface of the closed container 1 with a band or the like. The gas-liquid separator 2 has a gas-liquid separator suction port 15 on the upper side. The refrigerant pipe 2 a extending from the lower side of the gas-liquid separator 4 is connected to the suction passage 12 of the partition plate 10 via the connecting pipe 23. Connecting pipe 2
3 is constructed by welding the outer joint pipe and the inner joint pipe in an airtight manner. The outer connecting pipe is hermetically welded to the closed container 1, and the inner connecting pipe is welded to the refrigerant pipe 2a.

The operation of the hermetic compressor 20 described above will be described.

When the electric motor 21 is energized, the rotor 4 receives the rotational force from the stator 3 and is rotated, and the crankshaft 5 fixed to the rotor 4 is rotated. Due to the rotation of the two eccentric portions of the crankshaft 5, the two rollers 9 and 9A are eccentrically rotated in the compression chamber, and the vane 17 reciprocates in the vane groove. As a result, the refrigerant gas separated in the gas-liquid separator 2 is sucked into each of the low pressure chambers 25 of the two compression elements, transferred to the high pressure chamber 26 and compressed, and further discharged (not shown). From which a high-pressure refrigerant gas is discharged into the closed container 1. Explaining this suction flow of the refrigerant gas in detail, the refrigerant gas sucked from the suction pipe is the suction passage 1
2 is shunted to both sides by the communication hole 13 and is sucked into the low pressure chamber 25 through the cylinder suction port 14 of each compression element.

In this compression operation, HFC is used as a refrigerant.
Since the system refrigerant is used, the discharge pressure is generally 1.5 times higher than that using the HCFC refrigerant, so that the space in the closed container 1 is filled with the refrigerant gas having the pressure 1.5 times. It will be. The high-pressure refrigerant gas in the closed container 1 is discharged onto the container upper member 1c by welding or the like.
Is discharged to the external high-pressure pipe via.

In this embodiment described above, the sub bearing 11
The outer diameter of the sub bearing fitting portion 56 fitted into the main bearing 7 is made smaller than the outer diameter of the main bearing fitting portion 51 fitted into the main bearing 7, and the outer diameter of the two eccentric portions 52, 52A on the side opposite to the eccentric shaft A connecting portion 53 that is smaller than the outer diameter of the bearing fitting portion 51 and connects the two eccentric portions 52 and 52A.
Since a portion 54 having a diameter smaller than the outer diameter of the main bearing fitting portion 51 is provided on the shaft, and the axial length of the small diameter portion 54 is set to be equal to or greater than the height of the roller 52 on the main bearing side, the reliability of the crankshaft 5 is improved. It is possible to manufacture at a low cost with a minimum change while ensuring the above, and to increase the push-out amount or increase the seal length of the end surface of the roller 52 without increasing the overall size of the compressor. Capability or efficiency can be improved.

Further, the thickness of the partition plate 10 is made thicker than the thickness of the cylinder 8 which constitutes the compression element, and the suction passage 12 is formed.
Therefore, even in one suction passage 12, a large flow passage cross-sectional area can be secured, and the suction resistance of the refrigerant gas can be reduced to improve the compressor performance. In addition, since the single suction pipe line that penetrates the closed container 1 is formed, the suction pipe line can be halved, and the structure becomes simple, and the cost related to material cost, assembly process cost, etc. can be reduced. In addition to being able to achieve this, it is possible to eliminate stress concentration between the two suction pipe lines in the closed container 1, improve pressure resistance, and improve reliability. Further, the reliability can be sufficiently ensured even if an HFC-based refrigerant that is friendly to the global environment is used.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a vertical sectional view of a hermetically sealed two-cylinder rotary compressor according to a second embodiment of the present invention. The second embodiment is different from the first embodiment as described below,
The other points are basically the same as those of the first embodiment.

This second embodiment relates to a two-stage compression in which two compression elements are operated at different suction pressures and discharge pressures, and two compression elements are connected in series. Specifically, the compression element on the main bearing side is the first stage, and the compression element on the sub bearing side is the second stage.

When the crankshaft 5 is rotated, the refrigerant gas separated in the gas-liquid separator 2 from the gas-liquid separator 2 passes from the suction passage 12 of the cylinder 8 in the compression element on the main bearing side to the low-pressure chamber through the cylinder suction port 14. 25, the high pressure chamber 26 is moved to, and the first stage compression is performed. The refrigerant gas subjected to the first-stage compression is guided to the outside of the closed container 1 to be cooled, and after the contained lubricating oil is separated, from the suction passage 12A of the cylinder 8A in the compression element on the auxiliary bearing side. It is sucked into the low pressure chamber 25 through the cylinder suction port 14A, and is transferred to the high pressure chamber 26 to perform the second stage compression. The refrigerant gas compressed in the second stage becomes high-pressure refrigerant gas from a discharge hole (not shown), and the closed container 1
Is discharged inside.

According to the second embodiment, it is possible to obtain a higher pressure than that of the first embodiment under the condition that the overall shape of the compressor is the same, and the pressing amount of the compression element of each stage can be set arbitrarily. In addition, the compression element on the main bearing side can be provided in the first stage, and the degree of freedom in designing the compressor can be significantly improved. Of course, the basic effects of the present invention described in the first embodiment can also be obtained.

[0041]

As is apparent from the above description of each embodiment, according to the present invention, the reliability of the crankshaft can be ensured, the crankshaft can be manufactured at a minimum cost with a minimum change, and the entire compressor can be manufactured. (EN) A hermetic two-cylinder rotary compressor and a method for manufacturing the same, which can increase the amount of pushing or increase the seal length of the roller end face without increasing the size, thereby improving the performance or efficiency of the compressor. it can.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a hermetically sealed two-cylinder rotary compressor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

3 is an assembly process diagram of a crankshaft and a rotor used in the hermetic two-cylinder rotary compressor of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is an assembly process diagram of the modified example of FIG. 3;

FIG. 6 is a vertical sectional view showing a hermetically sealed two-cylinder rotary compressor according to a second embodiment of the present invention.

[Explanation of symbols]

1 ... Airtight container, 2 ... Gas-liquid separator, 2a ... Refrigerant piping, 3 ...
Stator, 4 ... Rotor, 5 ... Crank shaft, 6, 6A ... Bolt, 7 ... Main bearing, 8, 8A ... Cylinder, 9, 9A
... Roller, 10 ... Partition plate, 11 ... Sub bearing, 12
... Suction passage, 13 ... Communication hole, 14 ... Cylinder suction port, 1
5 ... Gas-liquid separator suction port, 16 ... Discharge pipe, 17 ... Vane, 18 ... Spring, 19 ... Refrigerant flow direction, 20 ... Closed type 2 cylinder rotary compressor, 21 ... Electric motor part, 22
... Compressor mechanism part, 23 ... Connection pipe, 25 ... Low pressure chamber, 2
6 ... High pressure chamber, 30 ... Compressor body.

Claims (6)

[Claims] 1. A hermetically sealed container is provided with an electric motor portion and a compression mechanism portion connected to the electric motor portion by a crankshaft provided with two eccentric portions having a phase difference of 180 degrees. Two cylinders each including one compression element, and two cylinders constituting each compression element are connected to each other through a partition plate, and a main body that supports the crankshaft by including the cylinder, the partition plate, and a closing portion that closes the cylinder. A hermetically sealed two-cylinder rotary compressor in which two compression chambers are constituted by a bearing and a sub-bearing, and a roller fitted to the eccentric portion is eccentrically rotated in the two compression chambers to perform a compression action. In, the outer diameter of the sub bearing fitting portion fitted into the sub bearing is smaller than the outer diameter of the main bearing fitting portion fitted into the main bearing, and the anti-eccentricity in the two eccentric portions is The outer peripheral surface on the shaft side is recessed from the outer peripheral surface of the main bearing fitting portion, and a portion having a diameter smaller than the outer diameter of the main bearing fitting portion is provided in the connecting portion that connects the two eccentric portions, and the small diameter portion A hermetically sealed two-cylinder rotary compressor having an axial length equal to or greater than the height of the roller on the main bearing side. 2. The hermetically sealed two-cylinder rotary compressor according to claim 1, wherein the partition plate has a thickness equal to or greater than the height of the roller on the main bearing side. 3. The circle according to claim 1 or 2, which has a larger diameter than the small outer diameter portion of the connecting portion and is concentric with the main bearing fitting portion between the small outer diameter portion of the connecting portion and the eccentric portion. A hermetically sealed two-cylinder rotary compressor characterized in that an arc-shaped large-diameter portion is integrally formed. 4. The arc-shaped large-diameter portion according to claim 3, wherein the arc-shaped large-diameter portion is provided only between the eccentric portion on the main bearing side and not on the eccentric portion on the sub-bearing side. Closed type 2 cylinder rotary compressor. 5. The compression element according to claim 1, wherein the two compression elements are connected in series, the compression element on the main bearing side is the first stage, and the compression element on the auxiliary bearing side is the second stage. A closed type two-cylinder rotary compressor characterized in that 6. A hermetically sealed container is provided with an electric motor section and a compression mechanism section connected to the electric motor section by a crankshaft provided with two eccentric sections having a phase difference of 180 degrees. Two cylinders each including one compression element, and two cylinders constituting each compression element are connected to each other through a partition plate, and a main body that supports the crankshaft by including the cylinder, the partition plate, and a closing portion that closes the cylinder. A hermetically sealed two-cylinder rotary compressor in which two compression chambers are constituted by a bearing and a sub-bearing, and a roller fitted to the eccentric portion is eccentrically rotated in the two compression chambers to perform a compression action. In the crankshaft, the outer diameter of the sub bearing fitting portion fitted in the sub bearing is smaller than the outer diameter of the main bearing fitting portion fitted in the main bearing, The outer diameter of the core portion on the side opposite to the eccentric shaft is made smaller than the outer diameter of the main bearing fitting portion fitted into the main bearing, and the connecting portion connecting the two eccentric portions has a diameter smaller than that of the main bearing fitting portion. With a small-diameter portion provided, the axial length of the small-diameter portion is formed to be equal to or higher than the height of the roller on the main bearing side, and then the roller on the main bearing side is inserted from the auxiliary bearing side of the crankshaft, Further, the method for manufacturing a hermetically sealed two-cylinder rotary compressor, characterized in that the eccentric portion on the side of the sub bearing and the connecting portion are passed through in order to be fitted to the eccentric portion on the side of the main bearing.