Compressor, method for manufacturing the compressor, defroster of refrigerant circuit, and refrigeration unit Number:7,435,062 from the United States Patent and Trademark Office (PTO) owispatent

Title: Compressor, method for manufacturing the compressor, defroster of refrigerant circuit, and refrigeration unit

Abstract: There is provided a rotary compressor capable of preventing deterioration of performance following plug fixing carried out to prevent falling-off of a spring member. The rotary compressor comprises a cylinder constituting a rotary compression element, a roller engaged with an eccentric portion formed in a rotary shaft of an electric element, and eccentrically rotated in the cylinder, a vane abutted on the roller to divide an inside of the cylinder into a low pressure chamber side and a high pressure chamber side, a spring member for always pressing the vane to the roller side, a housing portion of the spring member, formed in the cylinder, and opened to the vane side and a hermetically sealed container side, a plug positioned in the hermetically sealed container side of the spring member, and inserted into the housing portion to fit into a gap, and an O ring attached around the plug to seal a part between the plug and the housing portion. In this case, a space between the cylinder and the hermetically sealed container is set smaller than a distance from the O ring to an end of the plug on the hermetically sealed container side.

Patent Number: 7,435,062 Issued on 10/14/2008 to Tadano,   et al.

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Inventors:	Tadano; Masaya (Nitta-gun, JP), Yamasaki; Haruhisa (Ora-gun, JP), Matsumoto; Kenzo (Ora-gun, JP), Matsuura; Dai (Ota, JP), Sato; Kazuya (Ora-gun, JP), Saito; Takayasu (Ora-gun, JP), Ebara; Toshiyuki (Ota, JP), Imai; Satoshi (Ota, JP), Oda; Atsushi (Osaka, JP), Sato; Takashi (Kumagaya, JP), Matsumori; Hiroyuki (Ora-gun, JP)
Assignee:	Sanyo Electric Co., Ltd. (Moriguchi-Shi, JP)
Appl. No.:	10/790,181
Filed:	March 2, 2004

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Related U.S. Patent Documents

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	Application Number	Filing Date	Patent Number	Issue Date
	10225442	Aug., 2002	7128540

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Foreign Application Priority Data

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Sep 27, 2001 [JP]			2001-295634
Sep 27, 2001 [JP]			2001-295654
Sep 27, 2001 [JP]			2001-295663
Sep 27, 2001 [JP]			2001-295673
Sep 27, 2001 [JP]			2001-295678
Sep 27, 2001 [JP]			2001-295859
Sep 27, 2001 [JP]			2001-295866
Sep 27, 2001 [JP]			2001-296165
Sep 27, 2001 [JP]			2001-296180
Oct 09, 2001 [JP]			2001-311699
Oct 09, 2001 [JP]			2001-311702
Oct 12, 2001 [JP]			2001-315687
Oct 17, 2001 [JP]			2001-319401
Oct 17, 2001 [JP]			2001-319419
Oct 22, 2001 [JP]			2001-323757
Oct 22, 2001 [JP]			2001-323769
Oct 25, 2001 [JP]			2001-327809
Oct 25, 2001 [JP]			2001-327817
Oct 30, 2001 [JP]			2001-332796
Nov 30, 2001 [JP]			2001-366208

Current U.S. Class:	417/410.3 ; 184/6.16
Current International Class:	F04B 17/03 (20060101); F01M 1/00 (20060101)
Field of Search:	417/312,410.3 181/212,403 184/6.16 418/83,99,212

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References Cited [Referenced By]

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U.S. Patent Documents

4958992	September 1990	Winiger
5393206	February 1995	Roth et al.
5642991	July 1997	Singleterry et al.
6533064	March 2003	Kim et al.
6769267	August 2004	Ebara et al.
6835056	December 2004	van der Sluis et al.

Foreign Patent Documents

	358066019		Apr., 1983		JP
	61-106992		May., 1986		JP
	2-294586		Dec., 1990		JP
	5-256285		Oct., 1993		JP
	8-93671		Apr., 1996		JP
	8-247065		Sep., 1996		JP
	2000-104690		Apr., 2000		JP
	WO 01/73293		Oct., 2001		WO

Other References

European Patent Office Communication dated Dec. 23, 2002. cited by other . European Patent Office Communication dated Mar. 28, 2003. cited by other.

Primary Examiner: Freay; Charles G
Attorney, Agent or Firm: Kratz, Quintos & Hanson, LLP.

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Parent Case Text

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This application is a Divisional of prior application Ser. No. 10/225,442 filed on Aug. 22, 2002 now U.S. Pat. No. 7,128,540.

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Claims

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What is claimed is:

1. A rotary compressor comprising: an electric element, and first and second rotary compression elements driven by the electric element, both components being provided in a hermetically sealed container, gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged gas of intermediate pressure being further compressed by the second rotary compression element; first and second cylinders respectively constituting the first and second rotary compression elements; a first support member adapted to seal an opening surface of the first cylinder, and provided with a bearing of a rotary shaft of the electric element; a second support member adapted to seal an opening surface of the second cylinder, and provided with a bearing of the rotary shaft; and a carbon bush provided between one of the bearings of the first and second support members and the rotary shaft; wherein the bush is provided in the bearing of the second support member, wherein the compressor includes an oil reservoir, the first support member is adjacent to the oil reservoir, and no bushing is on the first support member.

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Description

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BACKGROUND OF THE INVENTION

The present invention relates to a compressor including an electric element, and a compression element driven by the electric element in a container, its manufacturing method, a defroster of a refrigerant circuit, and a refrigeration unit.

In a rotary compressor of such a conventional type, especially in a rotary compressor of an internal intermediate pressure multistage compression type, refrigerant gas is supplied through a refrigerant introduction tube and a suction passage, and sucked from a suction port of a first rotary compression element into a low pressure chamber side of a cylinder (first cylinder). The refrigerant gas is then compressed by operations of a roller and a vane engaged with an eccentric part of a rotary shaft to become intermediate pressure, and discharged from a high pressure chamber side of the cylinder through a discharge port and a discharge muffler chamber into a hermetically sealed container. Then, the refrigerant gas of the intermediate presser in the hermetically sealed container is sucked from a suction port of a second rotary compression element into a low pressure chamber side of a cylinder (second cylinder). The refrigerant gas is then subjected to second stage compression by operations of a roller and a vane engaged with an eccentric part of a rotary shaft to become one of a high temperature and high pressure. Then, it is supplied from the high pressure chamber through the discharge port, the discharge passage and the discharge muffler chamber, and discharged from a refrigerant discharge tube to the refrigerant circuit. The refrigerant gas then flows into a radiator constituting the refrigerant circuit with the rotary compressor. After heat radiation, it is squeezed by an expansion valve, heat-absorbed by an evaporator, and sucked into the first rotary compression element. This cycle is repeated.

The eccentric parts of the rotary shafts are provided to have a phase difference of 180.degree., and connected to each other by a connecting portion.

If a refrigerant having a large high and low pressure difference, for example carbon dioxide (CO.sub.2) as an example of carbon dioxide gas, is used for the rotary compressor, discharge refrigerant pressure reaches 12 MPaG at the second rotary compression element, in which pressure becomes high. On the other hand, it reaches 8 MPaG (intermediate pressure) at the first rotary compression element of a low stage side. This becomes pressure in the hermetically sealed container. Suction pressure of the first rotary compression element is about 4 MPaG.

The vane attached to such a rotary compressor is inserted in a groove provided in a radial direction of the cylinder so as to be freely moved in the radial direction of the cylinder. A spring hole (housing portion) opened to the outside of the cylinder is provided in a rear side of the vane (hermetically sealed container side), a coil spring (spring member) for always pressing the vane is inserted into the spring hole, an O ring is inserted into the spring hole from the opening outside the cylinder, and then sealed by a plug (pulling-out stopper) to prevent jumping-out of the spring.

In this case, eccentric rotation of the roller applies a force of extruding the plug from the spring hole to the outside. Especially, in the rotary compressor of the internal intermediate pressure type, since pressure in the hermetically sealed container becomes lower than that in the cylinder of the second rotary compression element, the plug is also extruded by a pressure difference between inside and outside of the cylinder. Thus, in the conventional case, the plug was pressed into the spring hole to be fixed to the cylinder. However, such pressure insertion deformed the cylinder to expand, forming a gap between it and a support member (bearing) for sealing the opening surface of the cylinder. Consequently, it was impossible to secure sealing in the cylinder, reducing performance.

In the rotary compressor of the internal intermediate pressure multistage compression type, since pressure (high pressure) in the cylinder of the second rotary compression element was higher than pressure (intermediate pressure) in the hermetically sealed container as an oil reservoir on a bottom part, it was extremely difficult to supply oil from an oil hole of the rotary shaft into the cylinder by using a pressure difference. Consequently, lubrication was carried out only by oil blended in the sucked refrigerant, causing a shortage of oil supply.

In the rotary compressor of the internal intermediate multistage compression type, the opening surface of the cylinder constituting the second rotary compression element is sealed by the support member, and the discharge muffler chamber is installed in this support member. FIG. 20 shows in section a support member 291 according to a conventional art. A bearing 291A of a rotary shaft is erected on a center of the support member 291, and a bush 292 is attached in the bearing 291A. A discharge muffler chamber 293 is concaved in the support member 291 outside the bearing 291A, and the discharge muffler chamber 293 is sealed by a cover 294. The cover 294 has a peripheral part fixed on the support member 291 by a plurality of bolts.

Here, because of higher pressure in the discharge muffler chamber 293 of the second rotary compression element than intermediate pressure in the hermetically sealed container, sealing by the cover 294 is an important problem. A gasket 296 is accordingly held between the cover 294 and the support member 291, but sealing is deteriorated because the centerbearing 291A side is away from the bolt. Thus, in the conventional case, a sealing surface 291B having a step was formed on a base of the bearing 291A, the gasket 296 was also held for sealing at this sealing surface 291B, a C ring 297 was attached to the bearing 291A, and an edge of the bearing 291A side of the cover 294 was pressed to the support member 291 side. Base 291C is the base of the bearing member 291A, as shown in FIG. 20. The base of the bearing member 291A is the portion where the sealing surface 291B is formed.

However, in the above-described conventional structure, the formation of the sealing surface reduced a capacity of the discharge muffler chamber, and necessitated the attaching of the C ring. Consequently, both processing and component costs were increased.

With regard to strength of the cover, if thin, the cover was deformed outside by the pressure difference between the discharge muffler chamber and the hermetically sealed chamber, causing gas leakage. Conversely, if too thick, it was impossible to secure an insulation distance from the electric element, causing an increase in a height dimension of the entire compressor.

The discharge pressure of the second rotary compression element becomes extremely high as described above. In the conventional case, however, each cylinder was fastened to the support member having the bearing by bolts arranged concentric circularly around the bearing. Consequently, there was a possibility of gas leakage from the cylinder.

When the high and low pressure difference is high as described above, if the connecting portion of the rotary shaft has a circular sectional shape coaxial to the rotary shaft, a sectional area to be physically secured is small, and the rotary shaft is easily deformed elastically. Thus, in the conventional case, in order to increase strength, a section of the connecting portion was formed in a rugby ball shape, in which a thickness in a direction orthogonal to the eccentric direction was larger than that in the eccentric direction of both eccentric portions. However, the number of processing steps was increased in a cutting process of the rotary shaft, deteriorating productivity.

In the compressor of the hermetically sealed type, the hermetically sealed container must be subjected to airtightness testing in a completion test of a manufacturing process. Pressure for this test is set to about 4 MPa in a normal compressor. However, if CO.sub.2 is used as a refrigerant as described before, since pressure (intermediate pressure in the above-described case) of the hermetically sealed container becomes extremely high, test pressure of about 10 MPa as a design upper limit of intermediate pressure is required. Consequently, it was difficult to easily connect a compressed air generator for applying the test pressure into the hermetically sealed container to the compressor.

To carry out gas-liquid separation of the refrigerant gas sucked into the first rotary compression element, an accumulator is attached to the hermetically sealed container. This accumulator is attached to a bracket welded to a side face of the hermetically sealed container by welding or a band, and held along the outside of the hermetically sealed container. However, if there is a need to increase a capacity of the accumulator or the like, the accumulator and a pile such as a refrigerant introduction tube may interfere with each other.

Therefore, conventionally, a shape of the bracket itself was changed to be separated from the pipe, or the holding position of the accumulator was changed to separate the accumulator itself from the pipe. In the former case, since the bracket was hooked on a hanger of a production device during painting of the hermetically sealed container, the hanger for painting had to be changed. In the latter case, since the accumulator was held away from its center (or position of center of gravity), vibration of the accumulator itself was increased, resulting in larger noise.

When the refrigerant gas of intermediate pressure discharged into the hermetically sealed container is sucked through another refrigerant introduction tube located outside the hermetically sealed container into the second rotary compression element, the refrigerant introduction tubes of the first and second rotary compression elements are connected to the hermetically sealed container in positions adjacent to each other.

Thus, wiring becomes difficult because of mutual interference between both refrigerant introduction tubes. Especially, since the accumulator was normally connected to the refrigerant introduction tube to the first rotary compression element, and this accumulator was arranged above the connecting position of each refrigerant introduction tube, interference easily occurred between both refrigerant introduction tubes, and it was difficult to lower the position of the accumulator.

In such a rotary compressor, a terminal for feeding power to the electric element is attached to an end cap of the hermetically sealed container. FIG. 23 shows in section a terminal 299 of the conventional rotary compressor. The terminal 299 was fixed by welding to an upper surface of an end cap 298 exhibiting an asymmetrical sectional shape at a center as shown.

In the end cap 298, by receiving an effect of high internal pressure, its welded part with the terminal 299 is deformed in a direction of being swelled outside. In an upper part of FIG. 23, a result of actually measuring a deformation amount of the end cap 298 is shown by region by region. In the drawing, a deformation amount of a region indicated by Z4 is 0.2 .mu.m. a deformation amount of a region indicated by Z5 is larger, i.e., 0.5 .mu.m, and a deformation amount of a region indicated by Z6 is increased further more to a maximum 0.9 .mu.m.

Thus, because of the largest deformation amount of the terminal 299, cracks or welding peeling-off occurred in the welded part between the terminal 299 and the end cap 298, consequently causing a reduction in pressure resistance performance.

FIG. 25 shows in section a terminal 300 of another rotary compressor. The terminal 300 includes a circular glass portion 302 provided with an electric terminal 307, and a metal attaching portion 303 formed around it. This attaching portion 303 was welded to a peripheral edge of an attaching hole 306 formed in a hermetically sealed container 304.

In this case, when the attaching portion 303 of the terminal 300 was too thin, strength (pressure resistance performance) against high pressure of refrigerant gas in the hermetically sealed container became insufficient, causing a failure such as cracks in the attaching portion 303. On the other hand, when too thick, a great amount of heat was necessary for welding the hermetically sealed container 304, causing damage to the glass portion 302 by the heat. Consequently, there was a danger of gas leakage or destruction.

An opening surface of a cylinder of such a rotary compressor is sealed by a support member constituting a discharge muffler chamber inside and, on a center of the support member, a bearing of a rotary shaft of an electric element is provided. Then, by providing a carbon bush capable of maintaining good sliding performance even in insufficient oil supply, and having high wear resistance performance even with respect to a high PV value (load applied per unit area) during a high load between the bearing and the rotary shaft, durability of the rotary compressor can be greatly improved. However, such a carbon bush was disadvantageous because a price was high, increasing competent costs.

The above-described refrigerant introduction and discharge tubes are connected to a cylindrical sleeve welded to a bent surface of the hermetically sealed container. Conventionally, however, a fixture was used to obtain perpendicularity of the sleeve with respect to an inner diameter of the hermetically sealed container. Consequently, assembling workability was deteriorated, lowering accuracy of perpendicularity.

For the rotary compression element to become high in pressure, a thin cylinder is used. Thus, since a suction passage or a discharge passage cannot be formed within the thickness range of the cylinder, a suction passage and a discharge passage are formed on the support member side sealing the opening surface of the cylinder and having a bearing and, in the cylinder, the suction and discharge ports for communicating the suction passage and the discharge passage with the inside of the cylinder are obliquely formed.

FIGS. 31 and 32 show a conventional processing method of such suction and discharge ports. In each drawing, a reference numeral 311 denotes a cylinder constituting a rotary compression element, 312 a suction port obliquely formed in the cylinder 311, and 313 a discharge port. In the case of forming the suction port 312, an end mill ML1 having a flat tip is set obliquely to the cylinder 311, i.e., in a direction perpendicular to a slope of the suction port 312, and moved in an inclining direction of the suction port 312 as indicated by an arrow in FIG. 31, thereby forming a groove inclined with respect to the cylinder 311.

On the other hand, in the case of forming the discharge port 313, the end mill ML1 is set obliquely to the cylinder 311, in this case, in an inclining direction of the discharge port 313, and extruded in the inclining direction of the discharge port 313 as indicated by an arrow in FIG. 32, thereby forming a notch inclined with respect to the cylinder 311.

Since the suction port 312 and the discharge port 313 were formed in the cylinder 311 in the conventional case as described above, an edge (right upper edge in FIG. 31) of a suction passage side of the suction port 312 was made linear, and an air flow of sucked gas on the connecting portion with the suction passage was disturbed, increasing passage resistance. In addition, since the end mill ML1 had to be set obliquely to the cylinder 311, processing was necessary separately from drilling similar to that for other screw holes or lightening holes, consequently increasing the number of processing steps, and production costs.

In the refrigerant circuit using the two-stage compression rotary compressor of the internal intermediate pressure type, a frost deposit is grown in the evaporator, and thus defrosting must be carried out. However, if a high-temperature refrigerant discharged from the second rotary compression element for defrosting in the evaporator is supplied to the evaporator without being pressure-reduced by a pressure reducing device (including a case of direct supplying to the evaporator, and a case of supplying with only passage through the pressure reducing device but without being pressure-reduced), suction pressure of the first rotary compression element is increased, thereby increasing discharge pressure (intermediate pressure) of the first rotary compression element.

This refrigerant is discharged through the second rotary compression element. However, because of no pressure reductions, discharge pressure of the second rotary compression element is set equal to the suction pressure of the first rotary compression element. Consequently, a reversal phenomenon occurred in pressure between the discharge (high pressure) and the suction (intermediate pressure) of the second rotary compression element in the conventional case.

Furthermore, in the rotary compressor of the internal intermediate multistage compression type, on the bottom portion, pressure (high pressure) in the cylinder of the second rotary compression element is set higher than pressure (intermediate pressure) in the hermetically sealed container as the oil reservoir. Consequently, it was extremely difficult to supply oil from the oil hole of the rotary shaft into the cylinder by using the pressure difference, and lubrication was carried out only by the oil blended in the sucked refrigerant, causing a shortage of oil supply.

SUMMARY OF THE INVENTION

The present invention was made to solve the foregoing problems inherent in the conventional art, and it is an object of the invention to provide a rotary compressor capable of preventing deterioration of performance following plug fixing carried out to prevent falling-off of a spring member.

That is, a rotary compressor of the present invention comprises an electric element, and a rotary compression element driven by the electric element, both components being provided in a hermetically sealed container, a cylinder constituting the rotary compression element, and a roller engaged with an eccentric portion formed in a rotary shaft of the electric element, and eccentrically rotated in the cylinder, a vane abutted on the roller to divide an inside of the cylinder into a low pressure chamber side and a high pressure chamber side, a spring member for always pressing the vane to the roller side, a housing portion of the spring member, formed in the cylinder, and opened to the vane side and the hermetically sealed container side, a plug positioned in the hermetically sealed container side of the spring member, and inserted into the housing portion to fit into a gap, and an O ring attached around the plug to seal a part between the plug and the housing portion. In this case, a space between the cylinder and the hermetically sealed container is set smaller than a distance from the O ring to an end of the plug on the hermetically sealed container side.

A rotary compressor of the present invention comprises an electric element, first and second rotary compression elements driven by the electric element, these components being provided in a hermetically sealed container, gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged gas of intermediate pressure being further compressed by the second rotary compression element, a cylinder constituting the second rotary compression element, a roller engaged with an eccentric portion formed in a rotary shaft of the electric element, and eccentrically rotated in the cylinder, a vane abutted on the roller to divide an inside of the cylinder into a low pressure chamber side and a high pressure chamber side, a spring member for always pressing the vane to the roller side, a housing portion of the spring member, formed in the cylinder, and opened to the vane side and the hermetically sealed container side, a plug positioned in the hermetically sealed container side of the spring member, and inserted into the housing portion to fit into a gap, and an O ring attached around the plug to seal a part between the plug and the housing portion. In this case, a space between the cylinder and the hermetically sealed container is set smaller than a distance from the O ring to an end of the plug on the hermetically sealed container side.

According to the present invention, the rotary compressor comprises the electric element, the rotary compression element driven by the electric element, both components being provided in the hermetically sealed container, the cylinder constituting the rotary compression element, the roller engaged with the eccentric portion formed in the rotary shaft of the electric element, and eccentrically rotated in the cylinder, the vane abutted on the roller to divide the inside of the cylinder into the low pressure chamber side and the high pressure chamber side, the spring member for always pressing the vane to the roller side, the housing portion of the spring member, formed in the cylinder, and opened to the vane side and the hermetically sealed container side, the plug positioned in the hermetically sealed container side of the spring member, and inserted into the housing portion to fit into a gap, and the O ring attached around the plug to seal a part between the plug and the housing portion. Thus, it is possible to prevent inconvenience of performance deterioration caused by a reduction made in sealing by cylinder deformation, which occurs in the case of pressing in, and fixing the plug in the housing portion.

Even if the plug is inserted to fit into the gap, since the space between the cylinder and the hermetically sealed container is set smaller than the distance from the O ring to the end of the plug on the hermetically sealed container side, at a point of time when the plug is moved in a direction of being extruded from the housing portion, and abutted on the hermetically sealed container to be prevented from being moved, the O ring is still positioned in the housing portion for sealing. Thus, no problems occur in a plug function.

Especially, the invention is remarkably advantageous in a rotary compressor of a multistage compression type having an inside of a hermetically sealed container set to intermediate pressure in that compressor performance is maintained and a spring member is prevented from being pulled out when CO.sub.2 gas is used as a refrigerant, intermediate pressure is set in the hermetically sealed container, and pressure in a second rotary compression element becomes extremely high.

A rotary compressor of the present invention comprises an electric element, a rotary compression element driven by the electric element, both components being provided in a hermetically sealed container, a cylinder constituting the rotary compression element, a roller engaged with an eccentric portion formed in a rotary shaft of the electric element, and eccentrically rotated in the cylinder, a support member adapted to seal an opening surface of the cylinder, and provided with a bearing of the rotary shaft, a vane abutted on the roller to divide an inside of the cylinder into a low pressure chamber side and a high pressure chamber side, a spring member for always pressing the vane to the roller side, a housing portion of the spring member, formed in the cylinder, and opened to the vane side and the hermetically sealed container side, and a plug positioned in the hermetically sealed container side of the spring member, and pressed into and fixed in the housing portion. In this case, the support member of a part corresponding to the plug includes a roll off concaved in a direction away from the cylinder.

A rotary compressor of the present invention comprises an electric element, first and second rotary compression elements driven by the electric element, these components being provided in a hermetically sealed container, gas compressed by the first compression element being discharged into the hermetically sealed container, and the discharged gas of intermediate pressure being further compressed by the second rotary compression element, a cylinder constituting the second rotary compression element, a roller engaged with an eccentric portion formed in a rotary shaft of the electric element, and eccentrically rotated in the cylinder, a vane abutted on the roller to divide an inside of the cylinder into a low pressure chamber side and a high pressure chamber side, a support member adapted to seal an opening surface of the cylinder, and provided with a bearing of the rotary shaft, a spring member for always pressing the vane to the roller side, a housing portion of the spring member, formed in the cylinder, and opened to the vane side and the hermetically sealed container side, and a plug positioned in the hermetically sealed container side of the spring member, and pressed into and fixed in the housing portion. In this case, the support member of a part corresponding to the plug includes a roll off concaved in a direction away from the cylinder.

According to the present invention, the rotary compressor comprises the electric element, the rotary compression element driven by the electric element, both components being provided in a hermetically sealed container, the cylinder constituting the rotary compression element, the roller engaged with the eccentric portion formed in the rotary shaft of the electric element, and eccentrically rotated in the cylinder, the support member adapted to seal the opening surface of the cylinder, and provided with the bearing of the rotary shaft, the vane abutted on the roller to divide the inside of the cylinder into the low pressure chamber side and the high pressure chamber side, the spring member for always pressing the vane to the roller side, the housing portion of the spring member, formed in the cylinder, and opened to the vane side and the hermetically sealed container side, and the plug positioned in the hermetically sealed container side of the spring member, and pressed into and fixed in the housing portion. The support member of a part corresponding to the plug includes the roll off concaved in a direction away from the cylinder. Thus, even if the pressing of the plug into the housing portion deforms the cylinder to swell to the support member side, the deformation of the cylinder is absorbed by the roll off, making it possible to prevent inconvenience of a gap formed between the cylinder and the support member. Therefore, it is possible to prevent inconvenience of performance deterioration caused by a reduction made in sealing by the cylinder deformation.

Especially, the invention is remarkably advantageous in a rotary compressor of a multistage compression type having an inside of a hermetically sealed container set to intermediate pressure in that compressor performance is maintained and a spring member is prevented from being pulled out when CO.sub.2 gas is used as a refrigerant, intermediate pressure is set in the hermetically sealed container, and pressure in a second rotary compression element becomes extremely high.

An object of the present invention is to smoothly and surely supply oil into a cylinder of a second rotary compression element of a second stage in a rotary compressor of an internal intermediate pressure multistage compression type.

That is, a rotary compressor comprises an electric element, first and second rotary compression elements driven by the electric element, these components being provided in a hermetically sealed container, gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged gas of intermediate pressure being further compressed by the second rotary compression element, cylinders constituting the respective rotary compression elements, an intermediate diaphragm provided between the cylinders to partition each rotary compression element, a support member adapted to seal an opening surface of each cylinder, and provided with a bearing of a rotary shaft, and an oil hole formed in the rotary shaft. In this case, the intermediate diaphragm includes an oil supply path for communicating the oil hole with a suction side of the second rotary compression element.

According to the present invention, the rotary compressor comprises the electric element, the first and second rotary compression elements driven by the electric element, these components being provided in a hermetically sealed container, gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged gas of intermediate pressure being further compressed by the second rotary compression element, the cylinders constituting the respective rotary compression elements, the intermediate diaphragm provided between the cylinders to partition each rotary compression element, the support member adapted to seal the opening surface of each cylinder, and provided with the bearing of the rotary shaft, and the oil hole formed in the rotary shaft. The intermediate diaphragm includes the oil supply path for communicating the oil hole with the suction side of the second rotary compression element. Thus, even in a state where pressure in the cylinder of the second rotary compression element is higher than intermediate pressure in the hermetically sealed container, by using a suction pressure loss in a suction process in the second rotary compression element, oil can be surely supplied from the oil supply path formed in the intermediate diaphragm into the cylinder.

Therefore, it is possible to secure performance and enhance reliability by assuring lubrication of the second rotary compression element.

In addition, according to the rotary compressor of the invention, the oil supply path is constructed by boring a through-hole in the intermediate diaphragm to communicate an outer peripheral surface with an inner peripheral surface of the rotary shaft side, and a communication hole for sealing an opening of the through-hole on the outer peripheral side, and communicating the through-hole with the suction side is bored on the cylinder for constituting the second rotary compression element.

According to the invention, in addition to the foregoing, the oil supply is constructed by boring the through-hole in the intermediate diaphragm to communicate the outer peripheral surface with the inner peripheral surface of the rotary shaft side, and the communication hole for sealing the opening of the through-hole on the outer peripheral surface side, and communicating the through-hole with the suction side is bored in the cylinder for constituting the second rotary compression element. Thus, it is possible to facilitate processing of the intermediate diaphragm to construct the oil supply path, and reduce production costs.

An object of the present invention is to carry out sure cover sealing for sealing a discharge muffler chamber of a second rotary compression element by simple constitution in a rotary compressor of an internal intermediate pressure multistage type.

That is, a rotary compressor of the present invention comprises an electric element, first and second rotary compression elements driven by the electric element, these components being provided in a hermetically sealed container, CO.sub.2 refrigerant gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged refrigerant gas of intermediate pressure being further compressed by the second rotary compression element, a cylinder constituting the second rotary compression element, a support member adapted to seal an opening surface of the cylinder, and provided with a bearing of a rotary shaft erected on a center part, a discharge muffler chamber formed in the support member outside the bearing, and communicated with an inside of the cylinder, a cover having a peripheral part fixed to the support member by a bolt to seal an opening of the discharge muffler chamber, a gasket held between the cover and the support member, and an O ring provided between an inner peripheral end surface of the cover and an outer peripheral surface of the bearing.

According to the present invention, the rotary compressor comprises the electric element, the first and second rotary compression elements driven by the electric element, these components being provided in the hermetically sealed container, CO.sub.2 refrigerant gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged refrigerant gas of intermediate pressure being further compressed by the second rotary compression element, the cylinder constituting the second rotary compression element, the support member adapted to seal the opening surface of the cylinder, and provided with the bearing of the rotary shaft erected on the center part, the discharge muffler chamber formed in the support member outside the bearing, and communicated with the inside of the cylinder, the cover having the peripheral part fixed to the support member by the bolt to seal the opening of the discharge muffler chamber, the gasket held between the cover and the support member, and the O ring provided between the inner peripheral end surface of the cover and the outer peripheral surface of the bearing. Thus, it is possible to prevent gas leakage between the cover and the support member by carrying out sufficient sealing with the inner peripheral end surface of the cover without forming any sealing surfaces on a base of the bearing.

Therefore, since a capacity of the discharge muffler chamber is increased, and the conventional necessity of fixing the cover to the bearing by the C ring is eliminated, it is possible to greatly reduce total processing and component costs.

An object of the present invention is to set a thickness dimension of a cover for sealing a discharge muffler chamber of a second rotary compression element to an optimal value in a rotary compressor of an internal intermediate pressure multistage compression type.

That is, a rotary compressor of the present invention comprises an electric element, first and second rotary compression elements driven by the electric element, these components being provided in a hermetically sealed container, CO.sub.2 refrigerant gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged refrigerant gas of intermediate pressure being further compressed by the second rotary compression element, a cylinder constituting the second rotary compression element, a support member adapted to seal an opening surface of the cylinder on the electric element side, and provided with a bearing of a rotary shaft erected on a center part, a discharge muffler chamber formed in the support member outside the bearing, and communicated with an inside of the cylinder, and a cover attached to the support member to seal an opening of the discharge muffler chamber. In this case, a thickness dimension of the cover is set to .gtoreq.2 mm to .ltoreq.10 mm.

In the rotary compressor of the invention, a thickness of the cover is set to 6 mm.

According to the present invention, the rotary compressor comprises the electric element, the first and second rotary compression elements driven by the electric element, these components being provided in the hermetically sealed container, CO.sub.2 refrigerant gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged refrigerant gas of intermediate pressure being further compressed by the second rotary compression element, the cylinder constituting the second rotary compression element, the support member adapted to seal the opening surface of the cylinder on the electric element side, and provided with the bearing of the rotary shaft erected on the center part, the discharge muffler chamber formed in the support member outside the bearing, and communicated with the inside of the cylinder, and the cover attached to the support member to seal the opening of the discharge muffler chamber. The thickness dimension of the cover is set to .gtoreq.2 mm to .ltoreq.10 mm, and the thickness of the cover is set to 6 mm. Thus, it is possible to miniaturize the compressor by securing an insulation distance from the electric element while securing strength of the cover itself, and preventing gas leakage caused by deformation.

In the rotary compressor of the invention, in each of the foregoing inventions, the cover has a peripheral part fixed to the support member by a bolt, a gasket is held between the cover and the support member, and an O ring is provided between an inner peripheral end surface of the cover and an outer surface of the bearing.

According to the invention, in addition to the foregoing, the cover has the peripheral part fixed to the support member by the bolt, the gasket is held between the cover and the support member, and the O ring is provided between the inner peripheral end surface of the cover and the outer surface of the bearing. Thus, it is possible to prevent gas leakage between the cover and the support member by carrying out sufficient sealing with the inner peripheral end surface of the cover without forming any sealing surfaces on the base of the bearing.

Therefore, since a capacity of the discharge muffler chamber is increased, and the conventional necessity of fixing the cover to the bearing by the C ring is eliminated, it is possible to greatly reduce total processing and component costs.

An object of the present invention is to effectively prevent gas leakage from a cylinder in a rotary compressor using CO.sub.2 as a refrigerant.

That is, a rotary compressor of the present invention comprises an electric element, first and second rotary compression elements driven by the electric element, these components being provided in a hermetically sealed container, CO.sub.2 refrigerant gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged refrigerant gas of intermediate pressure being further compressed by the second rotary compression element, a cylinder constituting each rotary compression element, a support member adapted to seal an opening surface of each cylinder, and provided with a bearing of a rotary shaft erected on a center, a discharge muffler chamber formed in the support member outside the bearing, and communicated with an inside of the cylinder, a cover attached to the support member to seal an opening of the discharge muffler chamber. In this case, each cylinder, each support member and each cover are fastened by a plurality of main bolts, and each cylinder and each support member are fastened by auxiliary bolts located outside the main bolts.

According to the present invention, the rotary compressor comprises the electric element, the first and second rotary compression elements driven by the electric element, these components being provided in the hermetically sealed container, CO.sub.2 refrigerant gas compressed by the first rotary compression element being discharged into the hermetically sealed container, and the discharged refrigerant gas of intermediate pressure being further compressed by the second rotary compression element, the cylinder constituting each rotary compression element, the support member adapted to seal the opening surface of each cylinder, and provided with the bearing of the rotary shaft erected on the center, the discharge muffler chamber formed in the support member outside the bearing, and communicated with the inside of the cylinder, the cover attached to the support member to seal the opening of the discharge muffler chamber. Each cylinder, each support member and each cover are fastened by the plurality of main bolts, and each cylinder and each support member are fastened by the auxiliary bolts located outside the main bolts. Thus, it is possible to improve sealing by preventing gas leakage between the cylinder of the second rotary compression element of high pressure, and the support member.

The rotary compressor of the invention further comprises a roller engaged with an eccentric portion formed in the rotary shaft of the electric element, and eccentrically rotated in the cylinder constituting the second rotary compression element, a vane abutted on the roller to divide an inside of the cylinder into a low pressure chamber side and a high pressure chamber side, and a guide groove formed in the cylinder to house the vane. The auxiliary bolts are positioned near the guide groove.

According to the invention, the rotary compressor further comprises the roller engaged with the eccentric portion formed in the rotary shaft of the electric element, and eccentrically rotated in the cylinder constituting the second rotary compression element, the vane abutted on the roller to divide the inside of the cylinder into the low pressure chamber side and the high pressure chamber side, and the guide groove formed in the cylinder to house the vane. The auxiliary bolts are positioned near the guide groove. Thus, it is also possible to effectively prevent gas leakage of back pressure applied to the vane by the auxiliary bolts.

An object of the present invention is to provide a rotary compressor capable of improving workability while increasing strength of a rotary shaft.

That is, a rotary compressor comprises an electric element, first and second rotary compression elements driven by the electric element, these components being provided in a hermetically sealed container, and gas compressed by the first rotary compression element being compressed by the second rotary compression element, first and second cylinders constituting the first and second rotary compression elements, and first and second rollers engaged with eccentric portions formed in a rotary shaft of the electric element to have a phase difference of 180.degree., and eccentrically rotated in the respective cylinders. In this case, a section of a connecting portion for connecting both eccentric portions with each other is formed in a shape having a thickness larger in a direction orthogonal to an eccentric direction than that in the eccentric direction of each of the eccentric portions, a side face of the connecting portion in the eccentric direction side of the first eccentric portion is formed in a circular-arc shape of the same center as that of the second eccentric portion, and a side face in the eccentric direction of the second eccentric portion is formed in a circular-arc shape of the same center as that of the first eccentric portion.

According to the present invention, the rotary compressor comprises the electric element, the rotary compression element driven by the electric element, these components being provided in the hermetically sealed container, and gas compressed by the first rotary compression element being compressed by the second rotary compression element, the first and second cylinders constituting the first and second rotary compression elements, and the first and second rollers engaged with the eccentric portions formed in the rotary shaft of the electric element to have a phase difference of 180.degree., and eccentrically rotated in the respective cylinders. The section of the connecting portion for connecting both eccentric portions with each other is formed in the shape having the thickness larger in the direction orthogonal to the eccentric direction than that in the eccentric direction of each of the eccentric portions. Thus, it is possible to increase rigidity strength of the rotary shaft, and effectively prevent its elastic deformation.

Especially, the side face of the connecting portion in the eccentric direction side of the first eccentric portion is formed in a circular-arc shape of the same center as that of the second eccentric portion, and the side face in the eccentric direction of the second eccentric portion is formed in a circular-arc shape of the same center as that of the first eccentric portion. Accordingly, it is possible to reduce the number of times of changing chucking positions during cutting of the rotary shafts having eccentric portions and connecting portions. Therefore, it is possible to reduce the number of processing steps, and costs by improved productivity.

An object of the present invention is to provide a hermetically sealed compressor capable of facilitating airtightness testing even when CO.sub.2 is used as a refrigerant and pressure in a hermetically sealed container becomes high.

That is, a hermetically sealed compressor comprises an electric element, a compression element driven by the electric element, both components being provided in a hermetically sealed container, a CO.sub.2 refrigerant sucked from a refrigerant introduction tube being compressed by the compression element, discharged into the hermetically sealed container, and then discharged outside from a refrigerant discharge tube, a sleeve provided in the hermetically sealed container, to which the refrigerant introduction tube and the refrigerant discharge tube are connected, and a flange formed around an outer surface of the sleeve to engage a coupler for pipe connection.

According to the present invention, the hermetically sealed compressor comprises the electric element, the compression element driven by the electric element, both components being provided in the hermetically sealed container, a CO.sub.2 refrigerant sucked from the refrigerant introduction tube being compressed by the compression element, discharged into the hermetically sealed container, and then discharged outside from the refrigerant discharge tube, the sleeve provided in the hermetically sealed container, to which the refrigerant introduction tube and the refrigerant discharge tube are connected, and the flange formed around an outer surface of the sleeve to engage the coupler for pipe connection. Thus, by using the flange, it is possible to easily engaged and connect the coupler provided for piping from a compressed air generator to the sleeve of the hermetically sealed container.

Therefore, it is possible to finish airtightness testing in a manufacturing process of the hermetically sealed compressor having high internal pressure.

A hermetically sealed compressor of the present invention comprises an electric element, a compression element driven by the electric element, both components being provided in a hermetically sealed container, a CO.sub.2 refrigerant sucked from a refrigerant introduction tube being compressed by the compression element, discharged into the hermetically sealed container, and then discharged outside from a refrigerant discharge tube, a sleeve provided in the hermetically sealed container, to which the refrigerant introduction tube and the refrigerant discharge tube are connected, and a screw groove formed for pipe connection around an outer surface of the sleeve.

According to the present invention, the hermetically sealed compressor comprises the electric element, the compression element driven by the electric element, both components being provided in the hermetically sealed container, a CO.sub.2 refrigerant sucked from the refrigerant introduction tube being compressed by the compression element, discharged into the hermetically sealed container, and then discharged outside from the refrigerant discharge tube, the sleeve provided in the hermetically sealed container, to which the refrigerant introduction tube and the refrigerant discharge tube are connected, and the screw groove formed for pipe connection around the outer surface of the sleeve. Thus, by using this screw groove, a pipe from a compressed air generator can be easily connected to the sleeve of the hermetically sealed container.

Therefore, it is possible to finish airtightness testing in a manufacturing process of the hermetically sealed container having high internal pressure within a short time.

A hermetically sealed compressor of the present invention comprises an electric element, a compression element driven by the electric element, both components being provided in a hermetically sealed container, a CO.sub.2 refrigerant sucked from a refrigerant introduction tube being compressed by the compression element, discharged into the hermetically sealed container, and then discharged outside from a refrigerant discharge tube, a plurality of sleeves provided in the hermetically sealed container, to which the refrigerant introduction tube and the refrigerant discharge tube are connected, a flange formed around an outer surface of one of adjacent sleeves to engage a coupler for pipe connection, and a screw groove formed for pipe connection around an outer surface of the other sleeve.

According to the present invention, the hermetically sealed compressor comprises the electric element, the compression element driven by the electric element, both components being provided in the hermetically sealed container, a CO.sub.2 refrigerant sucked from the refrigerant introduction tube being compressed by the compression element, discharged into the hermetically sealed container, and then discharged outside from the refrigerant discharge tube, the plurality of sleeves provided in the hermetically sealed container, to which the refrigerant introduction tube and the refrigerant discharge tube are connected, the flange formed around the outer surface of one of adjacent sleeves to engage the coupler for pipe connection, and the screw groove formed for pipe connection around the outer surface of the other sleeve. Thus, by using the flange, the coupler provided in the pipe from the compressed air generator can be easily engaged and connected to one of the sleeves of the hermetically sealed container. By using the screw groove, the pipe from the compressed air generator can be easily connected to the other sleeve of the hermetically sealed container. Therefore, it is possible to finish airtightness testing in a manufacturing process of the hermetically sealed compressor of high internal pressure within a short time.

Especially, since the flange is formed in one of the adjacent sleeves, and the screw groove is formed in the other sleeve, no couplers having relatively large dimensions are connected adjacently to each other and, even in the case of a narrow space between the sleeves, it is possible to connect a plurality of pipes from the compressed air generator by using the narrow space.

An object of the present invention is to provide a compressor capable of easily dealing with a capacity change of an accumulator.

That is, a compressor comprises an electric element, a compression element driven by the electric element, both components being provided in a container, a container side bracket provided in a side face of the container, an accumulator, and an accumulator side bracket, to which the accumulator is attached. In this case, by fixing the accumulator side bracket to the container side bracket, the accumulator is attached to the container through both brackets.

According to the compressor of the invention, the accumulator side bracket is attached to a center or a position of a center of gravity of the accumulator, or in the vicinity thereof.

According to the present invention, the compressor comprises the electric element, the compression element driven by the electric element, both components being provided in the container, the container side bracket provided in the side face of the container, the accumulator, and the accumulator side bracket, to which the accumulator is attached. By fixing the accumulator side bracket to the container side bracket, the accumulator is attached to the container through both brackets. Thus, when a capacity of the accumulator is changed, interference with the pipe can be prevented only by changing the accumulator side bracket without changing the hermetically sealed container side bracket. Therefore, it is possible to prevent an effect to a compressor manufacturing device.

In addition, even when the capacitor of the accumulator is changed, only by changing the accumulator side bracket, the accumulator side bracket is attached to its center or a position of a center of gravity, or in the vicinity thereof, and the accumulator can be held on the center or the position of a center of gravity of the accumulator, or in the vicinity thereof. Thus, it is also possible to prevent an increase of noise by vibration.

An object of the present invention is to provide a compressor capable of increasing space efficiency without any mutual interferences between first and second refrigerant introduction tubes.

That is, a compressor of the present invention comprises an electric element, first and second compression elements driven by the electric element, these components being provided in a hermetically sealed container, a refrigerant introduction tube for introducing a refrigerant to the first compression element, a refrigerant tube for introducing refrigerant gas compressed by the first compression element to the second compression element, and a refrigerant tube for discharging high pressure gas compressed by the second compression element. In this case, the refrigerant tubes of the first and second compression elements are c