JP2004239133A - Sealed type scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability of a sealed type scroll compressor while preventing destruction of ozone layer and global warming-up by using ammoniacal coolant. <P>SOLUTION: The sealed type scroll compressor 100 is comprised of a compressing mechanism part 2 having a fixed scroll 5 and a turning scroll 6 in a sealed vessel 1, a motor part 3 including a stator 3a and a rotor 3b, a drive shaft 14 connected to the rotor 3b to drive the compressing mechanism part 2 and supported by slide bearings 32, 39, and lubricating oil 22 supplied to the slide bearings 32, 39. The ammoniacal coolant is used as operation coolant and the lubricating oil 22 incompatible with the ammoniacal coolant is used. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hermetic scroll compressor, and is particularly suitable for a hermetic scroll compressor used for an air conditioner or a refrigerating device.
[0002]
[Prior art]
Since a CFC-based refrigerant that has been conventionally used as a working refrigerant for a compressor causes destruction of the earth's ozone layer and causes global warming, it has been considered to use a natural refrigerant such as ammonia. However, ammonia has the property of being flammable, toxic, and highly corrosive.
[0003]
Therefore, as a conventional ammonia refrigerant electric compression device, one disclosed in Japanese Patent Application Laid-Open No. H10-112949 (Patent Document 1) has been devised. This compressor has a hermetically sealed compression section that compresses a refrigerant fluid by ammonia, an electric motor that drives this compression section, and a circulation system that circulates lubricating oil that lubricates the compression section and the mechanical frictional motion portion of the electric motor. It is configured to be housed in a container. Each part of the motor is insulated with a resin material, and the wires of the winding of the motor are formed using a nickel-plated copper wire or a tin-plated copper wire. The lubrication system is designed to lubricate using a lubricating oil (ether-based oil) having compatibility with ammonia. Further, an upper bearing portion and a lower bearing portion are provided for supporting a rotor shaft of the electric motor.
[0004]
[Patent Document 1]
JP 10-112949 A
[Problems to be solved by the invention]
However, in the above-described compression device, a large amount of the ammonia refrigerant is dissolved in the lubricating oil supplied to the bearing portion by using the lubricating oil having compatibility with ammonia. For this reason, the viscosity of the lubricating oil supplied to the bearing portion by the dissolved ammonia refrigerant is reduced, and the lubrication characteristics of the bearing portion are reduced, which may cause damage to the bearing portion.
[0006]
Further, in the above-described compression device, when the upper bearing portion and the lower bearing portion for supporting the rotor shaft are made of a simple copper-based bearing material, the bearing portion made of the copper-based material is included in the lubricating oil. There is a problem that it is not possible to obtain sufficient reliability because it is corroded by the removed ammonia. On the other hand, when the bearing portion is made of a white metal or aluminum-based material, there is a problem that the bearing portion cannot be used under a high load.
[0007]
An object of the present invention is to obtain a highly reliable hermetic scroll compressor while preventing ozone layer destruction and global warming by using an ammonia refrigerant.
[0008]
Another object of the present invention is to obtain a sealed scroll compressor which can be used under a high load and has high reliability while preventing ozone layer destruction and global warming by using an ammonia refrigerant.
[0009]
Other objects and advantages of the present invention will be apparent from the following description.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a compression mechanism unit having a fixed scroll and an orbiting scroll, an electric motor unit having a stator and a rotor, and the compression mechanism coupled to the rotor. In the hermetic scroll compressor that drives the section and accommodates a drive shaft supported by a slide bearing and a lubricating oil supplied to the slide bearing, an ammonia refrigerant is used as a working refrigerant, and the lubricating oil is used as the lubricating oil. The present invention is characterized in that an incompatible lubricating oil is used for the ammonia refrigerant.
[0011]
In order to achieve the other object, the present invention provides, in a closed container, a compression mechanism section having a fixed scroll and an orbiting scroll, an electric motor section having a stator and a rotor, and being coupled to the rotor. A hermetic scroll compressor that drives a compression mechanism and accommodates a drive shaft supported by a slide bearing and lubricating oil supplied to the slide bearing, wherein an ammonia refrigerant is used as a working refrigerant, and The present invention has a configuration in which a sliding bearing containing porous bronze and a tetrafluoroethylene resin is used as the bearing.
[0012]
The other means of the present invention will be apparent from the following description.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a hermetic scroll compressor according to an embodiment of the present invention will be described with reference to FIGS.
[0014]
As shown in FIG. 1, the hermetic scroll compressor 100 of the present embodiment constitutes a part of a refrigeration cycle of a refrigeration / air-conditioning apparatus. In the refrigeration cycle, an ammonia refrigerant is used, and a hermetic scroll compressor 100 that compresses a gas of the ammonia refrigerant as a working refrigerant, a condenser 101 that condenses the compressed ammonia refrigerant, and decompresses the condensed ammonia refrigerant. The apparatus includes a pressure reducing device 102, an evaporator 103 for evaporating the decompressed ammonia refrigerant, and a refrigerant pipe 104 connecting these to a closed loop.
[0015]
The hermetic scroll compressor 100 is connected to a compression mechanism section 2 having a fixed scroll 5 and an orbiting scroll 6, an electric motor section 3 having a stator 3a and a rotor 3b, and a rotor 3b in a closed vessel 1. The drive mechanism 14 that drives the compression mechanism 2 and is supported by the slide bearings 32 and 39 and the cylindrical roller bearing 40, and accommodates the lubricating oil 22 supplied to the slide bearings 32 and 39 and the cylindrical roller bearing 40. Have been. Specifically, the compression mechanism 2 is accommodated in the upper part of the vertically long sealed container 1, and the electric motor 3 is accommodated in the lower part. The inside of the sealed container 1 is divided by a frame 7 into an upper chamber 1a and an electric motor chamber 1b.
[0016]
The compression mechanism 2 includes a fixed scroll 5, an orbiting scroll 6, and a frame 7. The fixed scroll 5 and the orbiting scroll 6 are arranged so as to mesh with each other, and a compression chamber 8 is formed between them.
[0017]
The fixed scroll 5 includes a disk-shaped end plate 5a and a wrap 5b standing upright on the end plate 5a and having an involute curve or a curve similar thereto, and discharges refrigerant gas from the compression chamber 8 to the center. And a suction port 14 for sucking refrigerant gas into the compression chamber 8 at the outer peripheral portion. The discharge port 10 is open to the discharge chamber 1a.
[0018]
As shown in FIG. 2, the orbiting scroll 6 has a disk-shaped end plate 6a, an upright wrap 6b formed in the same shape as the wrap 5b of the fixed scroll 5, and a wrap surface formed on the opposite side of the end plate 6a. Boss 6c.
[0019]
A sliding bearing 39 constituting an auxiliary bearing and a cylindrical roller bearing 40 constituting a main bearing are provided at the center of the frame 7. The drive shaft 14 is supported on these bearings 39 and 40. The outer periphery of the frame 7 is fixed to and supported by the closed container 1. The fixed scroll 5 is fixed to the frame 7 by a plurality of bolts 81.
[0020]
An eccentric shaft portion 14a is formed on one side of the drive shaft 14. The eccentric shaft portion 14a is inserted into the boss portion 6c of the orbiting scroll 6 so as to be capable of orbiting motion. The boss portion 6c is provided with a slide bearing 32 constituting a swing bearing. On the other side of the drive shaft 14, a motor shaft portion 14b is formed. The rotor 3b of the motor section 3 is directly connected to the motor shaft section 14b.
[0021]
The slide bearings 32 and 39 are constituted by slide bearings containing porous bronze and ethylene tetrafluoride resin. As shown in FIG. 3, the slide bearing 32 includes a back metal 32a made of steel or a copper alloy, an intermediate layer 32b containing porous bronze 32d and a tetrafluoroethylene resin 32e, and a surface layer containing a tetrafluoroethylene resin 32e. 32c. In the present embodiment, the intermediate layer 32b is formed by mixing porous bronze 32d into tetrafluoroethylene resin 2e, and the surface layer 32c is formed only of tetrafluoroethylene resin. With the multilayer structure including the back metal 32a, the intermediate layer 32b, and the surface layer 32c, the wear resistance can be improved while the corrosion resistance to the ammonia refrigerant is improved, so that the reliability is significantly improved. Can be. The sliding bearing 39 has a similar structure.
[0022]
Further, the surface layer 32c of the above-described slide bearing 32 is deleted (for example, cut) to expose the intermediate layer 32b to the surface, as shown in FIG. 4, and to form a porous bronze 32d and a tetrafluoroethylene resin 32e. If both are exposed, the wear resistance can be further improved while the corrosion resistance is improved.
[0023]
The orbiting scroll 6 is disposed between the frame 7 and the fixed scroll 5, is supported by the frame 7 by an Oldham mechanism 38 including an Oldham ring and an Oldham key, and is configured to make a revolving motion without rotating with respect to the fixed scroll 5. Have been.
[0024]
A suction pipe 17 extending through the closed casing 1 is connected to a suction port 16 of the fixed scroll 5. The inlet 16 is provided with a check valve 13. An O-ring 53 is provided between the suction pipe 17 and the fixed scroll 5 to seal the high pressure portion and the low pressure portion.
[0025]
The upper chamber 1a in which the discharge port 10 is open communicates with the motor chamber 1b via passages 18a and 18b. The passage 18a is formed by a gap between the fixed scroll 5 and the side wall 1m of the closed casing 1, and the passage 18b is formed by a gap between the frame 7 and the side wall 1m of the closed casing 1.
[0026]
The motor unit 3 is disposed in a motor room 1b formed below the compression mechanism unit 2 and includes a stator 3a fixed to a side wall 1m of the closed casing 1 and a rotor 3b fixed to a motor shaft unit 14b. It is configured. Note that a hermetic terminal 37 for energizing the motor unit 3 is attached to the closed casing 1.
[0027]
The motor room 1 b is connected to a discharge pipe 20 penetrating through the closed casing 1. Thus, the discharge port 10 and the discharge pipe 20 are communicated with each other via the discharge chamber 1a, the passages 18a and 18b, and the motor chamber 1b. The upper and lower portions of the motor chamber 1b are communicated with each other via a gap 25a between the stator 3a and the rotor 3b and a gap 25b between the stator 3a and the side wall 1m of the closed casing 1.
[0028]
On the back surface of the end plate 6a of the orbiting scroll 6, a space 36 (hereinafter referred to as a back pressure chamber) surrounded by the compression mechanism 2 and the frame 7 is formed. An intermediate pressure between the suction pressure and the discharge pressure is introduced into the back pressure chamber 36 through a fine hole 6 d formed in the end plate 6 a of the orbiting scroll 6. Thus, an axial force for pressing the orbiting scroll 6 against the fixed scroll 5 is given.
[0029]
The lubricating oil 22 is stored at the bottom of the closed container 1. As the lubricating oil 22, an oil incompatible with the ammonia refrigerant is used, and specifically, a naphthenic or paraffinic mineral oil, an alkylbenzene oil, or the like is used. The oil plate 47 is disposed on the oil surface of the lubricating oil 22.
[0030]
In the above-described configuration, when the motor 3 is energized and the rotor 3b is rotated, the motor shaft 14b directly connected to the rotor 3b is rotated, and accordingly, the eccentric shaft 14a is eccentrically rotated. As a result, the orbiting scroll 6 orbits through the sliding bearing 32. Due to this swirling motion, the compression chamber 8 gradually moves from the periphery to the center and the volume decreases. Along with this, the refrigerant gas enters the suction chamber 5f from the suction pipe 17 through the suction port 16, and starts to be compressed in the compression chamber 8.
[0031]
On the other hand, the lubricating oil 22 stored at the bottom in the sealed container 1 is sucked up through the oil suction pipe 27 by a differential pressure between the high pressure in the sealed container 1 and the intermediate pressure in the back pressure chamber 23, and is then driven The central hole 13 in the shaft 14 is raised, and oil is supplied to the sliding bearing 32 from the upper end opening of the central hole 13 and to the sliding bearing 39 and the cylindrical roller bearing 40 via the lateral hole 51. The lubricating oil 22 supplied to the bearings 32, 39, and 40 is injected into the compression chamber 8 through the back pressure chamber 36, through the hole 6d, and mixes with the refrigerant gas being compressed.
[0032]
The refrigerant gas containing the lubricating oil is discharged from the discharge port 10 into the upper chamber 1a after being compressed in the compression chamber 8, and flows into the electric motor chamber 1b through the passages 18a and 18b. In FIG. 1, solid arrows indicate the flow of the refrigerant gas, and broken arrows indicate the flow of the lubricating oil.
[0033]
Refrigerant gas (including lubricating oil) flowing from the narrow passages 18a and 18b into the motor chamber 1b in the wide space passes through the gaps 25a and 25b in the vertical direction to reach the lower motor chamber, and upward again to the upper motor chamber. Return to In this process, a part of the lubricating oil contained in the refrigerant gas is separated. On the other hand, the flow direction of the refrigerant gas flowing into the motor chamber 1b and colliding with the upper surface of the stator 3a is changed. In the process, a part of the lubricating oil contained in the gas is separated and flows out into the discharge pipe 20. The separated lubricating oil flows down through the gap 25b on the outer periphery of the stator and remains at the bottom of the closed casing 1.
[0034]
According to the present embodiment, since the ammonia refrigerant is used as the working refrigerant and the lubricating oil 22 incompatible with the ammonia refrigerant is used as the lubricating oil, the ammonia refrigerant hardly dissolves in the lubricating oil 22. Thereby, the clay of the lubricating oil 22 supplied to the slide bearings 32, 39 does not decrease even when the ammonia refrigerant is used, and the lubrication characteristics of these bearings 32, 39 can be improved. As a result, the bearings 32 and 39 can be prevented from being damaged while the ozone layer destruction and global warming are prevented, so that the sealed scroll compressor 100 having high reliability can be obtained.
[0035]
In addition, since the ammonia refrigerant is used as the working refrigerant and the slide bearings 32 and 39 containing porous bronze and tetrafluoroethylene resin are used as the slide bearings, the bearing portion is made of a white metal or aluminum-based material. In comparison, it can be used under a high load and the corrosion resistance to the ammonia refrigerant can be improved. As a result, the sealed scroll compressor 100 which can be used under a high load while improving the ozone layer depletion prevention and global warming prevention, improves the corrosion resistance of the slide bearings 32 and 39, and has high reliability can be obtained. .
[0036]
Further, when an ammonia refrigerant is used as a working refrigerant, a lubricating oil 22 incompatible with the ammonia refrigerant is used as a lubricating oil, and sliding bearings 32 and 39 containing porous bronze and tetrafluoroethylene resin are used as the sliding bearings. In this case, the lubricating oil discharged into the refrigeration cycle together with the ammonia gas easily returns to the compressor, and these effects are synergized to obtain a highly reliable hermetic scroll compressor 100.
[0037]
In the present embodiment, the machine housed in a container integrally formed by welding is shown, but a scroll compressor housed in an integrated container in which flange portions are combined by bolting or the like is also included in the present invention. It is.
[0038]
【The invention's effect】
As apparent from the above description, according to the present invention, it is possible to obtain a highly reliable hermetic scroll compressor while preventing ozone layer destruction and global warming using an ammonia refrigerant.
[0039]
Further, according to the present invention, it is possible to obtain a hermetic scroll compressor that can be used with a high load and has high reliability while preventing ozone layer destruction and preventing global warming using an ammonia refrigerant.
[Brief description of the drawings]
FIG. 1 is a sectional view of a hermetic scroll compressor according to an embodiment of the present invention.
FIG. 2 is a sectional view of an orbiting scroll used in the compressor shown in FIG. 1 and a slide bearing used therein.
FIG. 3 is a schematic sectional view of the slide bearing of FIG. 2;
FIG. 4 is a schematic sectional view of a modified example of the slide bearing of FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Closed container, 1a ... Discharge chamber, 1b ... Electric motor room, 1m ... Side wall, 2 ... Compression mechanism part, 3 ... Electric motor part, 3a ... Stator, 3b ... Rotor, 5 ... Fixed scroll, 5a ... Fixed scroll end plate 5b wrap, 5f suction chamber, 6 orbiting scroll, 6a orbiting scroll head, 6b wrap, 6c boss, 7 frame, 8 compression chamber, 10 discharge port, 14 drive shaft, 14a ... Eccentric shaft part, 14b ... Electric motor shaft part, 16 ... Suction port, 17 ... Suction pipe, 18a, 18b ... Pathway, 20 ... Discharge pipe, 22 ... Lubricant oil, 27 ... Oil suction pipe, 100 ... Closed scroll compression Machine.

Claims (8)

A compression mechanism portion having a fixed scroll and an orbiting scroll, an electric motor portion having a stator and a rotor, and a drive coupled to the rotor to drive the compression mechanism portion and supported by a sliding bearing in a closed container. In a hermetic scroll compressor containing a shaft and lubricating oil supplied to the slide bearing,
A hermetic scroll compressor using an ammonia refrigerant as a working refrigerant and a lubricating oil incompatible with the ammonia refrigerant as the lubricating oil. A compression mechanism portion having a fixed scroll and an orbiting scroll, an electric motor portion having a stator and a rotor, and a drive coupled to the rotor to drive the compression mechanism portion and supported by a sliding bearing in a closed container. In a hermetic scroll compressor containing a shaft and lubricating oil supplied to the slide bearing,
A hermetic scroll compressor, wherein an ammonia refrigerant is used as a working refrigerant, and a slide bearing containing porous bronze is used as the slide bearing. The hermetic scroll compressor according to claim 2, wherein a lubricating oil incompatible with the ammonia refrigerant is used as the lubricating oil. The hermetic scroll according to any one of claims 1 to 3, wherein a slide bearing containing a copper-tin alloy and a resin such as a tetrafluoroethylene resin, a polyamide resin, or a polyacetal resin is used as the slide bearing. Compressor. As the sliding bearing, a sliding bearing having a back metal made of steel or a copper alloy, an intermediate layer containing a resin such as a copper-tin alloy and a tetrafluoroethylene resin, a polyamide resin, or a polyacetal resin, and a surface layer containing the resin The hermetic scroll compressor according to any one of claims 1 to 3, wherein: The hermetic scroll compressor according to any one of claims 1 to 3, wherein the bearing is a sliding bearing that exposes a resin such as a copper-tin alloy, a tetrafluoroethylene resin, a polyamide resin, or a polyacetal resin to a surface layer. The hermetic scroll compressor according to any one of claims 1 to 6, wherein a naphthenic or paraffinic mineral oil is used as the lubricating oil. The hermetic scroll compressor according to any one of claims 1 to 6, wherein an alkylbenzene oil is used as the lubricating oil.

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