JP3585511B2 - Hermetic compressor - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a hermetic rotary compressor that compresses a refrigerant gas in a refrigeration apparatus or an air conditioner.
[0002]
[Prior art]
5 and 6 show a conventional hermetic rotary compressor.
[0003]
FIG. 5 is a longitudinal sectional view, and FIG. 6 is a transverse sectional view.
In FIG. 5, reference numeral 1 denotes an airtight container, in which an electric motor 2 composed of a stator 2a and a rotor 2b is installed.
[0004]
A compression mechanism 3 is provided below the electric motor 2, and the compression mechanism 3 is driven by the electric motor 2.
[0005]
Thus, the compressed refrigerant introduced from the suction hole 5 through the suction pipe 4 through an accumulator (not shown), after once discharged into hermetic container 1 from the discharge hole 6, provided above the closed container 1 The refrigerant is supplied from the discharge pipe 7 to the refrigeration cycle side. The compression mechanism 3 is configured as follows . A shaft 8 driven by the electric motor 2 is supported by a main bearing 9 and penetrates through a cylinder 10, and a lower end of the shaft 8 is supported by an auxiliary bearing 11. The inside of the cylinder 10 of the shaft 8 is a crank portion 12 (eccentric portion). A roller 13 is fitted between the crank portion and the cylinder 10, and the rotation of the shaft 8 causes the roller 13 to perform a planetary motion.
[0006]
A vane 14 is provided through the cylinder 10, and one end of the vane 14 contacts the outer periphery of the roller 13 by the urging force of the spring 15 to divide the inside of the cylinder 10 into a suction chamber 16 and a discharge chamber 17. The vane 14 reciprocates according to the planetary motion of the roller 13.
[0007]
The refrigerant gas is sucked from the suction hole 5 according to the planetary motion of the roller 13 accompanying the rotation of the shaft 8, compressed and discharged from the discharge notch 19. Contains the refrigerating machine oil 20. The refrigerating machine oil 20 is sucked up by a pump 21 provided at the lower end of the shaft 8 by the rotation of the shaft 8, and lubricates each sliding portion.
[0008]
It is the vane 14 that particularly poses a problem of wear in the sliding portion of such a compression mechanism.
[0009]
The vane 14 reciprocates with the rotation of the shaft 8. At this time, the pressure difference between the two chambers in the divided cylinder 10 causes the vane 14 to rub against the inner surface of the through hole 22 of the cylinder 10. Become. Further, since the end of the vane 14 is pressed against the roller 13 by the pressure of the spring 15 and the rear surface of the vane, the vane tip and the outer periphery of the roller 13 also slide. This sliding portion is not directly supplied with oil from the oil pump 21 unlike other sliding portions (such as a shaft bearing portion). The supply of oil to this portion is conventionally lubricated by oil contained in the suctioned refrigerant and oil oozing from the roller end, so that the supply amount cannot be expected to be large, and the temperature of the sliding portion is reduced by the compression of the refrigerant. High temperatures resulted in the most severe sliding, often causing wear. To solve this problem, in JP-A-57-173589 oil injector mechanism 51 as shown in FIG. 7 has been proposed. An oil injector mechanism 51 is mounted on the lower part of the cylinder 10 so as to communicate with the suction hole 5 , and a valve and a coil spring 54 are opened and closed by a pressure difference with an oil supply pipe 52 formed of a capillary tube having one end immersed in the refrigeration oil 20. It consists of.
[0010]
For a time greater abnormally high operating loads roller 13 and the vane 14 in the cylinder 10 is subject to wear, the spring force so as to be larger than the closed container 1 in pressure during normal operation of the coil spring 54, abnormal high pressure operation by setting smaller than the closed container 1 in the pressure of incoming are the cylinder 10 was stored in the bottom in the sealed container 1 refrigerating machine oil 20 together by entering the inlet bore 5 with the refrigerant gas due to the pressure difference, It is supplied to the surfaces of the rollers 13 and the vanes 14 in the cylinder to prevent wear.
[0011]
Further, at the time of normal operation, it is intended to prevent high-temperature oil from entering the suction passage and lowering the efficiency.
[0012]
Conventionally, dichlorodifluoromethane (hereinafter referred to as Freon 12 (CFC12)) or hydrochlorodifluoromethane (hereinafter referred to as Freon 22 (HCFC22)) has been mainly used as a refrigerant for such a closed type refrigerating compressor. As the refrigerating machine oil 20 sealed in the compression mechanism 5, a naphthenic or paraffinic mineral oil having solubility in the CFC 12 or the HCFC 22 is used.
[0013]
Since these refrigerants and refrigerating machine oil circulate directly in the closed container 1, the compression mechanism 3 needs to have wear resistance.
[0014]
By the way, it has become clear that the release of chlorofluorocarbons from the above-mentioned refrigerants has led to the destruction of the ozone layer and has serious effects on human bodies and ecosystems. Has been decided to abolish.
[0015]
Under these circumstances, 1,1,1,2-tetrafluoroethane (hereinafter referred to as Freon 134a (HFC134a)), 1,1-difluoroethane (hereinafter referred to as 152a (HFC152a)), Difluoromethane (hereinafter referred to as chlorofluorocarbon 32 (HFC32)) or a refrigerant mixture thereof has been developed.
[0016]
The refrigerant of Freon 134a, Freon 152a and Freon 32 has a low ozone depletion coefficient, but hardly dissolves in mineral oil which is a refrigerating machine oil used in the use of Freon 12 and Freon 22. Therefore, when Freon 134a, Freon 152a, Freon 32, or a refrigerant mixture thereof is used as a refrigerant for a refrigerant compressor, ether oil, ester oil, fluorine, Attempts have been made to use system oils and the like.
[0017]
[Problems to be solved by the invention]
However, in the case of a refrigerant compressor using HFC134a, HFC152a, or HFC32 instead of Freon 12 or Freon 22 as a refrigerant and having compatibility with these refrigerants as a refrigerating machine oil, for example, a polyalkylene glycol-based oil or a polyester-based oil In addition, the wear resistance of FC25, special cast iron, sintered alloy, stainless steel, etc. used as the sliding member of the above-described compression mechanism 5 is reduced, and the refrigerant compressor cannot be operated stably for a long time. The problem has arisen.
[0018]
This is because when Freon 12 or Freon 22 is used as a conventional refrigerant, chlorine (Cl) atoms in the Freon react with Fe atoms of the metal base to form an iron chloride film having good wear resistance. On the other hand, when Freon 134a, Freon 152a, or Freon 32 is used, since a Cl atom is not present in these compounds, a lubricating film such as an iron chloride film is not formed, and the lubricating action is reduced. There is one of the causes.
[0019]
Furthermore, conventional mineral oil-based refrigerating machine oils contain cyclic compounds and have relatively high oil film forming ability, whereas refrigerating machine oils compatible with Freon 134a, Freon 152a and Freon 32 are mainly composed of chain compounds. In addition, the inability to maintain an appropriate oil film thickness under severe sliding conditions is a factor that promotes a decrease in wear resistance.
[0020]
As described above, Freon 134a (HFC134a), Freon 152a (HFC152a), or Freon 32 (HFC32), which is a new refrigerant replacing Freon 12 (CFC12) and Freon 22 (HCFC22), is compatible with these refrigerants. In a refrigerant compressor using refrigerating machine oil, not only when the load is high, but also under a normal load, the sliding condition becomes severe. In particular, abrasion between the vane 14 and the roller 13 has become a major problem.
[0021]
In order to solve such a problem, for example, if the spring disclosed in Japanese Patent Application Laid-Open No. 57-173589 is weakened or oil injection is performed even under a normal load, high-temperature oil is injected into the suction hole to suck the oil. The problem of overheating the refrigerant and reducing the efficiency of the compressor is assumed.
[0022]
The present invention has been made in order to solve such a problem. In particular, even under a normal load using an HFC-based refrigerant, a slidable vane having a severe sliding condition, an oil film between rollers is formed without lowering the efficiency, and the wear resistance is improved. It is an object of the present invention to provide a refrigerant compressor with improved life and a longer life.
[0023]
[Means for Solving the Problems]
The present invention provides a rolling piston type rotary compressor in which a compressor element driven by a driving element having an electric motor in an airtight container is lubricated with an oil reservoir and a suction hole at a bottom portion in the airtight container of the rolling piston type rotary compressor. It communicates by a path, is provided with a throttle portion in the vicinity of the suction hole of the oil supply path, and a holder provided with a fine hole as a configuration of the throttle portion is attached to a sub-bearing or a cylinder. The present invention is applied to a compressor using HFC as a refrigerant and using a refrigerating machine oil compatible with the refrigerant.
[0024]
[Action]
With this configuration, oil is supplied to the sliding portion during operation not only by the oil pump, but also during normal operation of the compressor using the HFC system as a refrigerant, the pressure difference between the suction hole and the oil reservoir (discharge pressure) and the throttle. An appropriate amount of oil corresponding to the load is mixed into the suction refrigerant by the section, and this oil forms an appropriate oil film especially between the vane and the roller.
[0025]
Refrigerant is dissolved in the oil in the oil reservoir, and the oil that has passed through the oil supply path is decompressed by the throttle immediately before the suction hole. At this time, the refrigerant that has melted evaporates and cools the oil, so that the temperature of the oil decreases and enters the suction hole immediately after cooling, so that the suction refrigerant does not overheat. As a result, the reliability between the sliding parts, particularly between the vanes and the rollers, is improved without lowering the efficiency.
[0026]
【Example】
FIG. 1 is a longitudinal sectional view of one embodiment of the compressor of the present invention, and FIG. 4 is a transverse sectional view thereof. A motor unit 2 and a compression mechanism unit 3 are arranged inside the container 1, and a shaft 8 directly connected to the motor unit is supported by a main bearing 9 and a sub-bearing 11. A roller 13 is disposed in the cylinder 10 and penetrates the shaft and the eccentric part to perform a planetary motion.
[0027]
Inserted vanes in the through hole 22 of the cylinder 10 is found pressed against the roller 13 by a spring 15 and the back pressure (discharge pressure), divides the cylinder interior space in the discharge chamber and the suction chamber 16.
[0028]
Refrigeration oil 20 is sealed in the bottom of the sealed container 1 to a level at which the entire cylinder can be used during normal operation. Conventionally, naphthenic or paraffinic mineral oils and alkylbenzene synthetic oils are generally used for the refrigerants R12 and R22 in the conventional refrigerants R12 and R22. However, in the case of HFC-based refrigerants, ether-based ester-based oils compatible with refrigerants are used. Sealed. In a normal operation state, a considerable amount of refrigerant is dissolved in the refrigerating machine oil at the bottom of the closed vessel due to its compatibility.
[0029]
A suction hole 5 is formed in the cylinder 10 and is connected to an accumulator (not shown) via the suction pipe 4 .
[0030]
The suction hole 5 and the oil reservoir at the bottom of the sealed container are connected by an oil supply path 20. The oil supply path 20 is composed of a holder 25 having a hole 24 and a throttle portion, which is formed at a right angle to the cylinder suction hole, and an oil supply pipe 26 which encloses the holder and is attached to the auxiliary bearing 11. The oil supply pipe 26 is opened near the bottom of the sealed container, and a filter 27 is attached to the tip of the oil supply pipe 26 for the purpose of protecting the clogging of the throttle section. FIG. 2 shows details of a mounting portion of the holder 25 having a narrowed portion.
[0031]
The holder 25 are press-fitted tubules are the capillary to have a throttling effect and a hole with the following diameters 1 mm. It is also possible to make a thin hole directly in the holder instead of this thin tube. A holding hole 23 of the holder is provided in the sub bearing at a position opposite to the hole 24 opening to the cylinder suction hole 5. A screw is cut at the end of the holding hole 23, and the holder 25 is fixed to the sub-bearing with the screw portion, whereby the tip of the holder is crimped to the cylinder to perform high-low pressure sealing.
[0032]
This structure allows easy mounting.
Thereby, the throttle portion can be arranged near the suction hole 5.
[0033]
When the holder is attached to the sub bearing, the oil supply pipe 25 may be omitted because the holder opening is located considerably below.
[0034]
FIG. 3 shows an example in which a holder 25 having a throttle portion is attached to the cylinder 10. When attached to a cylinder, the throttle can be closer to the suction hole.
[0035]
The operation of this configuration will be described. The shaft 8 is driven by the electric motor 2, and due to the planetary motion of the roller 8, refrigerant gas such as HFC is sucked from the suction pipe 4 through the suction hole 5 into the suction chamber 16, the pressure is increased in the compression chamber 17, and the discharge notch 19 is formed. Is discharged from the discharge hole 6 into the closed container 1. At this time, the vane 14 that partitions the suction chamber 16 and the compression chamber 17 is pressed against the outer periphery of the roller 13 by the pressure applied to the spring 15 and the back of the vane, and moves while sliding on the sliding portion 31. The lubricating oil at the sliding point is mainly lubricated by the oil mixed into the suction gas. Although the suction gas entering the suction pipe 4 contains a small amount of refrigerating machine oil circulating in the refrigerant cycle together with the refrigerant gas, this amount alone is insufficient for an HFC in which the refrigerant is not particularly slidable.
[0036]
Naturally, the suction port has a low pressure, and dust is removed by the filter 27 due to the pressure difference between this portion and the high pressure section of the oil reservoir, and oil is supplied to the suction port in the order of the oil supply pipe and the throttle. Since the oil in the oil reservoir is selected in consideration of the compatibility with the refrigerant to be used, a considerable amount of the refrigerant is contained. The oil containing the refrigerant has a high temperature and a high pressure in the oil reservoir, but is decompressed in the throttle unit 28 . At the time of this pressure reduction, the refrigerant evaporates, the oil is cooled by the heat of vaporization, and the cooled oil is mixed into the suction hole. In the case of the conventional oil injection mechanism, since the capillary tube is disposed in the oil reservoir, the pressure is reduced by the capillary tube immersed in the oil reservoir. For this reason, even if the oil in the thin tube is cooled, it immediately receives heat from the surrounding oil, and oil having a temperature close to the surrounding high-temperature oil is mixed into the suction hole, causing overheating of the suction gas and causing compression. The efficiency of the machine was reduced.
[0037]
However, since the throttle portion of the present invention is arranged close to the suction hole, the cooled oil is not mixed into the suction hole without receiving heat from the surroundings, and the efficiency does not decrease.
[0038]
The oil mixed in the suction hole enters the suction chamber 16 and moves together with the roller 13 to the compression chamber. A part at this time enters the sliding portion 31 between the roller 13 and the vane 14 and forms an oil film to prevent abrasion.
[0039]
The oil mixed into the suction hole and lubricating the sliding portion is discharged from the discharge hole 6 together with the discharge gas. The oil discharged from the discharge hole 6 is sieved while passing through the notch of the electric motor 2, and most of the oil returns to the oil reservoir. Therefore, the amount of oil that leaves the discharge pipe 7 and circulates in the refrigeration cycle can be reduced. When the amount of oil circulating in the refrigeration cycle is reduced, the heat exchange of the heat exchanger is not hindered by the oil, so that the efficiency of the refrigeration cycle is further improved.
[0040]
Further, since the oil mixed into the suction hole passes through the throttle portion, the larger the differential pressure, the larger the amount of oil mixed. This means that a greater amount of lubricating oil is supplied when the pressure difference that is severe for the sliding portion is large. Reliability is improved.
[0041]
As described above, the case where the compressed gas is the HFC-based refrigerant in which the sliding condition between the vane and the roller is particularly severe is described. However, the same effect can be expected in the conventional HCFC 22.
[0042]
【The invention's effect】
As described above, the present invention
An electric motor and a compressor element driven by the motor are axially connected in a closed container, and the compressor element is mounted in a cylinder and a main bearing and a sub-bearing fixed to both ends of the cylinder and the main bearing and a sub-bearing. A shaft rotatably housed and having a crank, a roller eccentrically rotating in the cylinder fitted to the crank of the shaft, and a reciprocating motion in a groove of the cylinder, and abutting on the roller to move through the cylinder. A suction hole configured to introduce a refrigerant into the compression element, a discharge hole configured to discharge the compressed refrigerant into a closed container, and an oil reservoir at a bottom of the closed container. The suction port communicates with the suction port through an oil supply path, and the throttle section of the oil supply path is constituted by a fine hole provided in the holder by a hermetic compressor having a throttle section provided near the suction hole of the oil supply path. Hermetic compressor mounted holders to sub-bearing.
[0043]
A hermetic compressor in which a throttle portion of an oil supply path is constituted by a fine hole provided in a holder, and the holder is mounted on a cylinder.
[0044]
The refrigerant is HFC, and in a hermetic compressor using refrigerating machine oil having compatibility with the refrigerant, an electric motor and a compressor element driven by the motor are axially connected in a closed vessel, and the compressor element is a cylinder. A shaft having a main bearing and a sub-bearing fixed to both ends of the cylinder, a crank rotatably housed in the main bearing and the sub-bearing, and a roller eccentrically rotating in the cylinder fitted to the crank of the shaft; A suction hole configured to reciprocate in the groove of the cylinder and to divide the inside of the cylinder into a suction chamber and a compression chamber by coming into contact with the roller to introduce a refrigerant into the compression element; A discharge hole for discharging into the closed container is provided, and the oil reservoir at the bottom of the closed container and the suction hole are connected by an oil supply path, and the oil supply section is close to the suction hole of the oil supply path. Ri unit hermetic compressor provided with.
[0045]
A hermetic compressor in which a throttle portion of an oil supply path is constituted by a fine hole provided in a holder, and the holder is mounted on a sub bearing.
[0046]
The throttle section of the oil supply path is constituted by a fine hole provided in the holder, and in the case of a hermetic compressor in which the holder is mounted on a cylinder, especially in a case where the sliding condition using HFC as a refrigerant is severe, even if the sliding condition is severe, By passing the oil through the throttle portion immediately before the suction hole, the oil contained in the oil evaporates and the cooled oil can be supplied to the sliding portion between the vane and the roller. Has high reliability. Further, since the supplied oil is cooled, the suction gas is not overheated, and the amount of oil circulating also in the refrigeration cycle is suppressed to a small degree, so that there are effects such as realizing a highly efficient device.
[0047]
In addition, since the throttle portion is constituted by a fine hole provided in the holder, the throttle portion can be arranged close to the suction hole, the overheating of the suction gas can be prevented, and the mounting can be easily performed.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a hermetic compressor according to the present invention. FIG. 2 is an enlarged sectional view of a main part of the hermetic compressor according to the present invention. FIG. 3 is a longitudinal section of another embodiment of a hermetic compressor according to the present invention. FIG. 4 is a cross-sectional view of a hermetic compressor according to the present invention. FIG. 5 is a longitudinal cross-sectional view of a conventional hermetic compressor. FIG. 6 is a cross-sectional view of a conventional hermetic compressor. Enlarged sectional view of a main part of a hermetic compressor according to another embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 Closed container 2a Stator 2b Rotor 2 Electric motor 3 Compression mechanism 4 Suction pipe 5 Suction hole 6 Discharge hole 7 Discharge pipe 8 Shaft 9 Main bearing 10 Cylinder 11 Sub bearing 12 Crank part (eccentric part)
13 roller 14 vane 15 spring 16 suction chamber 17 discharge chamber 18 suction hole 19 discharge notch 20 refrigerating machine oil 21 oil pump 22 through hole 23 holding hole 24 hole 25 holder 26 supply pipe 27 filter 31 sliding part 51 oil injector mechanism 52 oil supply Pipe 53 Valve 54 Coil spring 55 Internal hollow 56 Fitting tube 57 Valve

Claims (4)

An electric motor and a compressor element driven by the electric motor are arranged in an axial direction in a closed container having an oil reservoir for storing a refrigerating machine oil mixed with a refrigerant at a bottom portion, and the compressor element is a cylinder and both ends of the cylinder. A shaft having a main bearing and a sub-bearing fixed to and a crank rotatably housed in the main bearing and the sub-bearing;
A roller fitted eccentrically in the cylinder fitted to the crank of the shaft, and a vane reciprocating in a groove of the cylinder and dividing the inside of the cylinder into a suction chamber and a compression chamber by coming into contact with the roller. and, wherein a suction hole for introducing the refrigerant into the compressor element, and contact with the oil supply path a discharge hole provided constantly communicating the oil reservoir and the suction hole for discharging the compressed refrigerant into the sealed container, the oil supply path A hermetic compressor characterized in that a throttle portion having a diameter of 1 mm or less is provided in the vicinity of the opening on the suction hole side, and a refrigerant mixed with refrigerating machine oil is vaporized at the outlet of the throttle portion. 2. The hermetic compressor according to claim 1, wherein the throttle portion of the oil supply path is constituted by a fine hole provided in a holder, and the holder is mounted on a sub bearing. The hermetic compressor according to claim 1, wherein the throttle portion of the oil supply path is constituted by a fine hole provided in the holder, and the holder is mounted on a cylinder. 4. The hermetic compressor according to claim 1, wherein the refrigerant is HFC, and refrigerating machine oil compatible with the refrigerant is used.

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