JPH045485A - rotary compressor - Google Patents

Abstract

PURPOSE:To increase the heat insulation ability of a suction pipe fixed on the outer side of a case, and prevent suction refrigerant gas from being heated by forming a gap between the suction pipe and a seal pipe to be a thermal insulation space. CONSTITUTION:A gap is formed between a seal pipe 14 gas-tightly fixed to a rotation compression element 1 and a suction pipe 13 disposed on the inner side of it to be a thermal insulation space. A structure where the compression element 1 and the suction pipe 13 do not come in contact with each other directly is achieved, so a heat conductive way for heating suction refrigerant gas by heat conduction from the high temperature compression element 1 is disconnected, so the thermal insulation ability of the suction pipe 13 is increased largely. The refrigerant gas in the suction pipe 13 can thus be prevented from being heated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a rotary compressor incorporated in a refrigeration cycle of a refrigerator or the like, and particularly relates to a structure for preventing heating of intake gas due to heat generated due to gas compression.

[Conventional technology]

In a rolling piston type rotary compressor for a refrigeration cycle, a compression element and a motor serving as a drive mechanism are generally housed in the same sealed case, and a suction pipe is directly connected to the compression element. Since the inside of the sealed case is filled with compressed high-temperature, high-pressure refrigerant gas, the closed case and the compression chamber are heated by the high-temperature, high-pressure refrigerant gas, and their temperature increases. Therefore, the low-temperature, low-pressure refrigerant gas passing through the suction pipe is heated by the suction pipe to rise in temperature and flows into the compression element, so that the specific volume of the refrigerant increases and the refrigerating capacity decreases. For example, Japanese Patent Application Laid-open No. 63-68791 can be cited as an example of a method that improves this point.

[Problem to be solved by the invention]

In the above conventional technology, the suction pipe is made into a double pipe, and the gap between the cover pipe of the outer pipe and the suction pipe of the inner pipe is vacuumed and insulated, so the suction refrigerant is transferred by heat transfer from the high temperature discharge gas around the suction pipe. Although the rate at which the gas is heated can be reduced, the compression element becomes hot enough to account for most of the heat received by the suction refrigerant gas.

Heat is transferred from the sealed case to the suction pipe by conduction,
No consideration is given to the insulation of the heat transfer path from which the heat is transferred to the suction refrigerant gas. Therefore, an increase in the temperature of the suction refrigerant gas is unavoidable, and the specific volume of the refrigerant increases, reducing the volumetric efficiency of the compressor.

Further, the prior art does not consider reducing the temperature of the compression element, which is the basis for reducing the heating of the refrigerant gas sucked in, and preventing the influence of heat on the refrigerant gas discharged.

An object of the present invention is to provide a rotary compressor that improves the heat insulation of a suction pipe, prevents heating of suction refrigerant gas in the suction pipe, and has high volumetric efficiency.

[Means to solve the problem]

In order to achieve the above object, the rotary compressor of the present invention has a double suction pipe, a gap is formed between the seal pipe of the outer pipe and the insert pipe of the inner pipe, and the compression element and the insert pipe are The structure was designed so that there was no direct contact.

[Function] In the present invention, the suction pipe is made into a double pipe, and a gap is formed between the seal pipe of the outer pipe and the insert pipe of the inner pipe, so the gap acts as a gas layer and acts as a heat insulator. Since the insert pipe in the inner tube is structured so that it does not come into direct contact, the heat transfer path that heats the suction refrigerant gas through heat conduction from the high-temperature compression element is blocked, greatly improving the insulation properties of the suction pipe. , the heating of the refrigerant gas in the suction pipe can be prevented, so the volumetric efficiency of the compressor can be significantly improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal cross-sectional view of a rotary compressor showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a main part of FIG. Compression element 1 is connected to cylinder 2. A roller 3 that rotates eccentrically within the cylinder 2. Franch 4 that gives rolling rotation to the roller 3. A rotating shaft 59 integrally formed with the crunch 4. A main bearing 6 that supports the rotating shaft 5 and also serves as an end plate forming a compression chamber. A sub bearing shaft 7, a vane (not shown) that partitions the inside of the cylinder 2 into a suction chamber and a compression chamber and reciprocates inside the cylinder 2 while contacting the roller 3, a discharge valve provided in the sub bearing 7 (not shown) , discharge cover8. It is composed of a discharge silencer 9. This compression element 1 is housed in a case 10, and a portion thereof is immersed in lubricating oil 11 stored at the bottom. case 10
A motor 12 is housed in the other one, and the motor 12 includes a stator 12a fixed in the case 10 by shrink fitting or the like, and a rotor 12b fixed to the rotating shaft 5. One end of the seal pipe 13 is hermetically connected to the auxiliary bearing 7, and is welded and fixed to a connecting pipe 15 welded to the case 1o on the outside of the case 10. The suction pipe 14 is
Seal pipe 13 so that a gas layer 21 is formed around it.
It opens near a substantially arc-shaped suction notch 2a provided in the cylinder 2 that communicates with the suction chamber, and is welded and fixed to the seal pipe 13 on the outside of the case 10. The discharge pipe 16 is located in the case 1 above the suction pipe 14.
0 and is fixed to the case 10 by welding.

The operation of the rotary compressor configured in this way will be explained. The low-temperature, low-pressure refrigerant gas returned from the refrigeration cycle (not shown) connected to the suction pipe 14 and the discharge pipe 16 passes through the suction pipe 14 as shown by the arrow and enters the suction notch 2a of the cylinder 2. Flows into the suction chamber from the rotating shaft 5
The refrigerant gas, which has become high temperature and high pressure in the compression chamber due to the rotation of the , passes through a discharge valve (not shown), flows into the discharge silencer 9, and is discharged into the case 10. 16, it is circulated to the refrigeration cycle as shown by the arrow. Here, the outside of the suction pipe 13 is the gas layer 2.
1 and is surrounded by the seal pipe 14, the gas layer 21 becomes a heat insulating layer, and it is possible to reduce the rate at which the suction refrigerant gas in the suction pipe 13 is heated by heat transfer from the discharge refrigerant gas in the case 10. can. In addition, suction pipe 1
3 and the auxiliary bearing 7 constituting the compression element 1 are structured so that they do not come into direct contact with each other, so that the suction refrigerant gas in the suction pipe 13 is heated by heat conduction from the compression element 1, which has become high in temperature due to the heat of gas compression. The heat transfer path is cut off, and the thermal influence of gas compression heat can be suppressed. Therefore, dense refrigerant gas with a small specific volume is sucked into the cylinder 2, and the volumetric efficiency of the rotary compressor can be improved. Further, when the rotary compressor of the present invention is incorporated into a refrigeration cycle, the refrigeration capacity is increased and the energy efficiency of the refrigeration cycle can be improved.

FIG. 3 is a sectional view of a main part of a rotary compressor which is a second embodiment of the present invention. In the figure, a suction pipe 13 and a separate insert pipe 17 are inserted inside a seal pipe 14 fixed to a sub-bearing 7 to form a double pipe. A layer 21 is formed. Other configurations are shown in Figures 1 and 2.
It is similar to the embodiment shown in the figure and performs the same operation.

In this embodiment, the insert pipe 1 is inserted into the seal pipe 14.
7 is assembled with one end fixed,
The suction pipe 13 can be easily assembled, the double pipe portion can be configured with high precision, and the same effects as the embodiments shown in FIGS. 1 and 2 can be achieved.

FIG. 4 shows a method of manufacturing a double pipe by assembling the seal pipe 14 and insert pipe 17 shown in FIG. 3. In the figure, 18 is an assembly jig for setting the outer seal pipe 14 and the inner insert pipe 17 concentrically, and 19 and 20 are pipe crimping jigs. A groove is plastically worked on the outer periphery of the seal pipe 14 by a caulking jig 19, an insert pipe 17 is inserted inside, and the assembly jig 18 and the caulking jig 2 are inserted so that they are concentric.
It is set between 0 (Figure (a)). Next, as shown in the figure (b), the caulking jig 20 is inserted into the insert pipe 17, and the seal pipe 14 is expanded at the groove part.
An insert pipe 17 is fixed inside the seal pipe 14. Each jig is removed to create a double pipe pipe. (Figure (C)).

FIG. 5 is a sectional view of a main part of a rotary compressor showing another embodiment of the present invention, and FIG. 6 is a sectional view taken along the line vr--■ in FIG.

The rotary compressor of the present invention is an improvement of the second embodiment of the present invention shown in FIG. In order to maintain the gap, a plurality of protrusions 17a formed on the surface of the insert pipe 17 are used to maintain the gap, as shown in FIG. Normally, piping for a refrigeration cycle such as a refrigerator is subject to internal pressure, so copper pipes or the like with a thickness of about 0.8 mm are used. In this embodiment, since no pressure is applied to the insert pipe 17 constituting the double pipe pipe, the wall thickness can be significantly reduced (0.5 mm or less). Therefore, the inner diameter of the insert pipe 17 through which the suction refrigerant gas flows is kept large, the pressure loss in the piping can be reduced, and the volumetric efficiency of the rotary compressor can be improved. The insert pipe 17 can be made of a material with a low thermal conductivity, such as stainless steel, instead of a normal copper pipe, to further improve the heat insulation properties of the double-walled pipe. Moreover, the insert pipe 17 can be made into a multilayer structure using metal foil to improve the heat insulation properties.

FIG. 7 is a longitudinal sectional view of a rotary compressor showing an embodiment in which the present invention is applied to a vertically installed rotary compressor, and FIG.
FIG. 7 is a sectional view of the main part of FIG. 7; In this vertical rotary compressor, a motor 12 is located at the top of a case 10, a compression element 1 is disposed below the motor 12, and is immersed in lubricating oil 11 stored at the bottom of the case 10. The suction refrigerant gas directly flows into the suction chamber in the cylinder 2, which is fixed to the case 10 by welding. By fixing it to , the same effect as the second embodiment of the present invention shown in FIG. 3 can be achieved. In this embodiment, a rolling piston type rotary compressor has been described, but the present invention can also be applied to a multi-blade type rotary compressor.

FIG. 9 is a cross-sectional view of a horizontal rotary compressor according to another embodiment of the present invention, and corresponds to the cross-sectional view taken along the line IX-IX in FIG. FIG. 10 is a perspective view of the cylinder 2 shown in FIG. 9. In the figure, 2b is a discharge notch formed by partially cutting out the inner periphery of the cylinder 2, and 2c is a reinforcing rib. A suction chamber 2 is provided inside the cylinder 2 by a vane 22.
3 and the compression chamber 24, 625 is a bolt for assembling the compression element 1, and 26 is a bolt hole thereof. In this embodiment, the outer surface area of the cylinder 2 constituting the compression element 1 is
From the second half of the compression stroke where the temperature rises due to the gas compression action, to the discharge stroke, that is, the rotation $l1 based on the position of the vane 21.
The axis rotation angle θ taken in the rotation direction of 15 is approximately π≦θ≦2π
(rad). In other words, by reducing the wall thickness of the cylinder 2 in the above-mentioned range except for the bolt holes 26, and by providing reinforcing ribs 2c that also serve as radiation fins, the compression stroke can be achieved without changing the external dimensions of the cylinder 2. The outer surface area of the cylinder 2, which enters the discharge stroke from the latter half, is approximately doubled. Therefore, heat dissipation from the cylinder 2 is promoted and the temperature of the compression element 1 can be reduced, reducing the rate at which the suction refrigerant gas is heated by heat conduction from the compression element 1, improving the volumetric efficiency of the compressor. Since the heat dissipation of the operating refrigerant gas itself during the compression stroke is promoted, the temperature of the discharged refrigerant gas can also be reduced, and the temperature rise deteriorates the lubricating oil and generates carbon sludge, which can cause damage to the discharge valve. Carbonization of the adhering discharge valve is also prevented, and the reliability of the compressor can be improved. In addition, in order to expand the cylinder outer surface area from the second half of the compression stroke to the discharge stroke, fins or the like may be simply formed on the outer surface of the cylinder 1.

FIG. 11 is a longitudinal sectional view of a horizontal rotary compressor according to an embodiment of the present invention, and is an explanatory diagram of the flow of discharged refrigerant gas. FIG. 12 is a plan view of the sub bearing in FIG. 11, and FIG. This figure is a plan view of a discharge chamber consisting of a discharge cover and a discharge silencer in FIG. 11. In the figure, 27 is a discharge port formed in the secondary bearing 7, 28 is a discharge valve, and 29 is a retainer. When the gas in the compression chamber 24 becomes higher than the pressure in the case 10, the discharge valve 28 is deflected, and the gas is Discharge port 2
It is discharged from 7. The retainer 29 is the discharge valve 2 at that time.
It plays the role of a stopper of 8. The discharged refrigerant gas discharged from the discharge port 27 is as shown by the arrow in FIG.
From the discharge valve chamber 30 of the sub-bearing 7, it passes through the /IX hole 31 provided in the discharge cover 8, enters the first silencer small chamber 32, passes through the throttle part 33, enters the second silencer small chamber 34, and then enters the small silencer chamber 34. 35 into the third silencer chamber 36 of the sub-bearing 7, and is discharged into the case 10 through the discharge groove 37. In this way, the silencer into which high-temperature discharge refrigerant gas flows has a double structure, and the outer first silencer chamber 32 is composed of the discharge cover 8 and the silencer 9 into which the discharge gas is discharged.
．． It is configured to radiate heat to the surroundings through the second silencer chamber 34, and as is clear from FIG. Approximately π≦θ≦2π(ra
d), and is configured away from the suction side of the cylinder 2 into which low-temperature, low-pressure refrigerant gas flows, reducing the rate at which heat is transferred from the discharged refrigerant gas and heats the suction chamber 23 in the cylinder 2. be done. Therefore, high-density refrigerant gas is sucked into the suction chamber 23 of the cylinder 2, and the volumetric efficiency of the rotary compressor can be improved. Furthermore, when the rotary compressor of the present invention is incorporated into a refrigeration cycle, the refrigeration capacity is increased and the energy efficiency of the refrigeration cycle can be improved.

〔Effect of the invention〕

According to the present invention, the suction pipe is made into a double pipe, a gas layer gap is formed between the seal pipe of the outer pipe and the insert pipe of the inner pipe, and the structure is such that the compression element and the insert pipe do not come into thermal contact. Therefore, the heating rate of the suction refrigerant gas can be reduced, which has the effect of improving the volumetric efficiency of the rotary compressor.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a rotary compressor that is an embodiment of the present invention, Fig. 2 is a detailed view of the main part of Fig. 1, and Fig. 3 is a rotary compressor that is a second embodiment of the invention. Main part sectional view, 4th
The figure is an explanatory diagram of the method for manufacturing the double-pipe pipe shown in Fig. 3, Fig. 5 is a cross-sectional view of main parts showing the third embodiment of the present invention, and Fig. 6 is a cross-section taken along the line VI-VI in Fig. 5. FIG. 7 is a vertical sectional view of a vertical rotary compressor which is a fourth embodiment of the present invention, and FIG.
The figure is a detailed view of the main part of Figure 7, Figure 9 is a sectional view taken along the ■-■ arrow in Figure 1, Figure 10 is a perspective view of the cylinder in Figure 9,
1 is a vertical cross-sectional view of a rotary compressor according to a fifth embodiment of the present invention, FIG. 12 is a plan view of the secondary bearing of FIG. 11, and FIG.
The figure is a plan view of the discharge silencer of FIG. 11. 1... Compression element, 2... Cylinder, 3... Roller,
4. Crank, 5. Rotating shaft, 6. Main bearing, 7. Sub bearing. 8...Discharge cover, 9...Discharge silencer, 10.
...Case, 11...Lubricating oil, 12...Motor, 1
3... Suction pipe, 14... Seal pipe, 15.
...Connection pipe, 16...Discharge-pipe, 17...
Insert pipe, 18... Assembly jig, 19.20.
... crimping jig, 21 ... gas layer, 22 ... vane, 23 ... suction chamber, 24 compression chamber, 25 ... bolt,
26...Bolt hole, 27...Discharge port, 28...
Discharge valve, 29... Retainer, 3o... Discharge valve chamber, 3
1.35... Small hole, 32, 34° 36... Silencer small chamber, 33... Throttle part, 37... Discharge groove.

Claims (1)

[Claims] 1. In a rotary compressor in which a rotary compression element and a motor for driving the rotary compression element are housed in a case, and the inside of the case is kept at high pressure, a seal pipe airtightly fixed to the rotary compression element; A suction pipe is arranged inside the seal pipe, a gap is formed between the suction pipe and the seal pipe to form a heat insulating space, and the suction pipe and the seal pipe are fixed on the outside of the case. A rotary compressor characterized by: