JP2002371982A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reduction in volumetric efficiency even in a rotary compressor using a carbon dioxide refrigerant. SOLUTION: The rotary compressor 1 comprises a plurality of rotary compression elements 5 comprising cylinders 14 and 15 with both end openings closed, rollers 18 and 19 rotatable in the cylinders 14 and 15 by a rotary shaft 4, and vanes for forming a compression space in the cylinders 14 and 15 when butting against the rollers 18 and 19, houses the two rotary compression elements 5 in a hermetic container 2, and draws in a carbon dioxide refrigerant and discharges it after compression in the rotary compression elements 5. A minimum overlap width between the rollers 18 and 19 and a plate middle 13 is set at one third or larger of an axial thickness of the cylinders 14 and 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a rotary compressor using carbon dioxide (CO ₂ ) among natural refrigerants.

[0001]

2. Description of the Related Art As a prior art prior to the present invention, Japanese Patent No. 2517346 (F04B49 / 02) discloses:
A closed container having an oil reservoir at the bottom, a motorized element housed in the container, and a plurality of compression elements driven by the motorized element, the compression element is a cylinder,
A rotary shaft rotated by the electric element, a roller rotated along the inner wall of the cylinder by an eccentric portion of the rotary shaft, a vane reciprocatingly sliding in a groove provided in the cylinder in contact with the roller, It consists of a bearing that seals the opening of the cylinder, and separates each compression element with an intermediate partition plate.
In the compressor, the rotary shaft is provided with a first oil supply passage for supplying oil from an oil reservoir to each sliding portion.
The compression element is provided with a second oil supply passage for supplying oil from an oil reservoir into the cylinder, one end of the second oil supply passage is provided in the intermediate partition plate, and the other end of the first oil supply passage is provided with the first oil supply passage. A temperature detection element is provided in a discharge path of the compressor, and a temperature detection element is provided in a discharge path of the compressor, and on / off control of the compressor is performed based on a detection result of the temperature detection element. A control device for a compressor is disclosed.

[0002] In the conventional refrigeration cycle, Freon (R11, R12, R134a, etc.) has been generally used as a refrigerant. However, if CFCs are released into the atmosphere, they have problems such as a large warming effect and ozone layer depletion.

[0003] For this reason, in recent years, the impact on the environment is small.
Other natural refrigerants such as oxygen (O _Two),carbon dioxide
(CO_Two), Hydrocarbon (HC), ammonia
(NH_Three), Water (H_TwoResearch using O) as refrigerant
Have been.

[0004] Of these natural refrigerants, oxygen and water cannot be used as refrigerants in a refrigeration cycle because of their low pressure even when used in rotary compressors. In addition, since ammonia and hydrocarbons are flammable, there is a problem that handling is difficult.

Therefore, development of a compressor using CO _2, ie, carbon dioxide, has been desired.

Conventionally, compressors of reciprocating type and rotary type (rotary type) are roughly classified. However, reciprocating type compressors have problems of noise and vibration.

Therefore, development of a rotary compressor using carbon dioxide has been desired.

[0008]

In the case of a rotary compressor using Freon as a refrigerant, the overlapping portion of the roller and the plate middle is about 1.4 mm. When used, the pressure increases, so that the gas refrigerant leaks from the overlapping portion of the roller and the plate middle, and the volume efficiency deteriorates.

Further, since the compressor for carbon dioxide refrigerant has a high refrigeration capacity, the rejected volume can be very small. If this is dealt with by the outer diameter of the roller, the size becomes closer to the inner diameter of the cylinder, and the amount of eccentricity also becomes smaller. Therefore, there is a problem that the radial thickness of the compression chamber is reduced, and the volume efficiency is reduced.

The present invention has been made in view of the above-described problems, and has as its object to prevent a reduction in volumetric efficiency even in a rotary compressor using a carbon dioxide refrigerant.

[0011]

According to the first aspect of the present invention, there is provided a cylinder having an opening closed at both ends, a roller rotating in the cylinder by a rotating shaft, and a roller. A plurality of rotary compression elements consisting of vanes forming a compression space in the cylinder by abutting, a plurality of rotary compression elements are provided, and these rotary compression elements are accommodated in a closed container, and carbon dioxide refrigerant is sucked into the rotary compression elements. A rotary compressor that partitions the plurality of rotary compression elements, and includes a plate middle that closes one opening of a cylinder of each of the partitioned rotary compression elements. The minimum overlap width of the roller and the plate middle is set to 1/3 or more of the axial thickness of the cylinder, and the inside of the closed container is set to an internal low pressure or an intermediate pressure. Those were.

Therefore, gas leakage from the overlapping portion between the roller and the plate middle can be prevented as much as possible, and the reduction in volumetric efficiency can be prevented as much as possible, so that the rotary compressor can be reduced in size.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a two-cylinder rotary compressor having the present invention, FIG. 2 is an enlarged view of a rotary compressor element of the rotary compressor having the present invention, and FIG. 3 is a rotary compression element unit. FIG. 4 is a plan view of a rotary compression element unit, FIG. 5 is a refrigeration circuit diagram using a two-cylinder rotary compressor having the present invention, and FIG. 6 is a two-cylinder rotation having the present invention. Mollier diagram in a refrigeration circuit diagram using a compressor, FIG. 7 is a diagram showing the relationship between the amount of leakage and the amount of overlap between the roller and plate middle in a two-cylinder rotary compressor equipped with the present invention, FIG. 8 shows a second embodiment of the present invention.
FIG. 4 is a diagram showing a relationship between a cylinder thickness in a rotary compressor of a cylinder, a shaft pin portion load, and a suction passage resistance.

1 is a two-cylinder rotary compressor (rotary compressor) equipped with the present invention.
An electric element 3 provided at an upper portion in a closed container 2 made of metal such as iron, and a rotary compression element 5 provided below the electric element 3 and driven to rotate by a rotation shaft 4 of the electric element 3. It becomes. In the rotary compressor 1 of the present embodiment, two rotary compression elements 5 are provided, but a larger number of rotary compression elements 5 may be provided.

The lower part of the sealed container 2 is an oil reservoir 2.
C, and comprises a container 2A that houses the electric element 3 and the rotary compression element 5, and a sealing lid 2B that seals the container 2A, and supplies power to the electric element 3 to the sealing lid 2B. Terminal terminals for wiring (wiring omitted) 6
Is attached.

The electric element 3 is composed of a rotor 7 and a stator 8, and the rotor 7 is provided with a permanent magnet (not shown) inside a laminated body 10 composed of laminated electromagnetic steel sheets. The windings 11 are attached to a laminated body 12 in which a plurality of electromagnetic steel sheets are laminated.
In addition, 9 is a balancer. Although this structure is referred to as a DC motor, a motor referred to as an AC motor in which an aluminum core made of aluminum is inserted into a laminated electromagnetic steel plate may be used.

Further, when used for an air conditioner of a car or the like, an engine of the car or the like may be used as a drive source or another drive source.

The rotary compression elements 5 and 5 include a plate middle (intermediate partition plate) 13, upper and lower cylinders 14 and 15 mounted above and below the plate middle 13, and a rotary shaft inside the upper and lower cylinders 14 and 15. Upper and lower rollers 18 and 1 which are rotated by upper and lower pin portions (eccentric portions) 16 and 17 of FIG.
9, upper and lower vanes which are in contact with the upper and lower rollers 18, 19 to partition the inside of the upper and lower cylinders 14, 15 into a high pressure chamber and a low pressure chamber, and to close the upper and lower openings of the upper and lower cylinders 14, 15; Main frame 2 that allows rotation of
2, and a bearing plate 23.

Further, as shown in FIG.
The minimum overlap width between 8, 19 and the plate middle 13 is 3m
m or more. Thus, the upper and lower rollers 18, 19
Since the plate middle 13 and the plate middle 13 overlap at least 3 mm or more, even if the rotary compressor 1 uses a high-pressure carbon dioxide refrigerant, leakage from this portion can be prevented as much as possible.

FIG. 7 shows the relationship between the amount of overlap (mm) between the rollers 18 and 19 and the plate middle 13 and the amount of leakage.

According to FIG. 7, when the overlapping amount of the rollers 18, 19 and the plate middle 13 is less than 4 mm, the leak amount gradually increases, but it is within an allowable range up to about 3 mm. Assuming that the overlap amount is 4 mm or more, FIG.
As shown in (1), there is almost no change in the leak amount.
Therefore, it is desirable that the overlapping amount be 3 mm or more.
The overlap width (overlap amount) between the upper and lower rollers 18, 19 and the plate middle 13 is (roller outer diameter / 2)-(eccentric amount).
-(Diameter of the center hole of the plate middle / 2). Therefore, each numerical value is determined so that this numerical value becomes 3 mm or more.

Specifically, in the present embodiment, the outer diameter (diameter) of the upper roller 18 in the upper cylinder 14 is approximately 29 mm to 3 mm.
2 mm, the eccentric amount is about 2.0 mm to 2.6 mm, and the diameter of the center hole of the plate middle 13 is about 19 mm to 22 mm. From these ranges, each numerical value is determined so that the overlapping width is 3 mm or more.

The two-cylinder rotary compressor 1 of this embodiment has the following features. (1) The upper roller 18 is inserted into the upper pin portion 16 of the rotary shaft 4. (2) Insert the rotating shaft 4 into the main frame 22. (3) Insert the upper cylinder 14. (4) Insert the plate middle 13 (pass the lower pin portion 17). (5) Insert the lower roller 19 into the lower pin portion 17 of the rotating shaft 4. (6) Insert the lower cylinder 15. (7) Insert the bearing plate 23.

The procedure is as follows.

Accordingly, the diameter of the center hole of the plate middle 13 is large enough to allow the lower pin portion 17 to pass through, and is approximately the same as or slightly larger than the upper and lower pin portions 16 and 17.

The loads applied to the upper and lower pins 16, 17 are as follows:
In other words, the maximum pin load (upper or lower load)
The excluded volume ratio is determined so as to be within + 25% in the case of a rotary compressor using a Freon refrigerant. Therefore, the excluded volume ratio is in the range of 0.45 to 0.6. However, the preferred range is within + 10%. Further, as shown in FIG. 3, the thickness of the upper and lower cylinders 14 and 15 is reduced to 9 mm to 11 mm, and the inner diameter of the upper and lower cylinders 14 and 15 is set to 34 mm to 3 mm.
6 mm.

FIG. 8 shows the relationship among the cylinder thickness (mm), the suction passage area, the suction passage resistance, and the shaft pin load.

The shaft pin load (load applied to the upper and lower pin portions 16 and 17 of the rotating shaft 4) at the time of carbon dioxide refrigerant is as follows:
Compared to the case of Freon refrigerant, the load of Freon refrigerant is 1
It is desirably 25% or less. As shown in FIG. 8, when the load of the shaft pin portion in the case of carbon dioxide refrigerant is 125% of the load of the shaft pin portion in the case of Freon refrigerant, the cylinder thickness becomes 11 mm.

The suction passage resistance in the case of carbon dioxide refrigerant is desirably 200% or less of the passage resistance in the case of fluorocarbon refrigerant as compared with the case of fluorocarbon refrigerant. Then, as shown in FIG. 8, when the suction passage resistance at the time of carbon dioxide refrigerant is 200% of the suction passage resistance at the time of CFC refrigerant,
The cylinder thickness is 9 mm.

Therefore, the cylinder thickness is set in the range of 9 mm to 11 mm so that the above-mentioned shaft pin load is set to 125% or less in the case of Freon refrigerant and the suction passage resistance is set to 200% or less in the case of Freon refrigerant.

The suction passage area indicated by the dotted line in FIG. 8 increases as the cylinder thickness increases, and the suction passage resistance decreases with this increase.

Further, since the carbon dioxide refrigerant has a high refrigerating capacity, the excluded volume can be reduced as compared with the case where chlorofluorocarbon is used. If this excluded volume is handled only by the outer diameters of the upper and lower rollers 18 and 19, the outer diameter of the upper and lower rollers 18 and 19 becomes closer to the inner diameter of the upper and lower cylinders 14 and 15. For this reason, the amount of eccentricity is reduced, the radial thickness of the compression space is reduced, and the volume efficiency (intake efficiency) is reduced.

For this reason, it is necessary to reduce the height of the upper and lower cylinders 14 and 15 to cope with them. The height dimension of the upper and lower cylinders 14 and 15 is reduced, that is, 9 mm to 11 m.
By setting the range of m, the volumetric efficiency can be maintained satisfactorily, and the rotary compression element 5 can be reduced, so that the rotary compressor 1 can be downsized.

The above-described main frame 22, upper cylinder 14, plate middle 13, lower cylinder 15, and bearing plate 23 are arranged in this order, and are connected by bolts 24. As shown in FIG. 4, the bolt mounting position on the main frame 22 side and the bolt mounting position on the bearing plate 23 side are shifted as shown in FIG. 4 so that they do not interfere with each other. Therefore, even if the thickness of the rotary compression element 5 is small, the screw portion of the bolt 24 can securely screw each component.

An oil supply hole 25 for supplying oil A to each sliding portion of the rotary compression element 5 is provided in the rotary shaft 4.
Is provided. Further, the outer peripheral surface of the rotating shaft 4 communicates with the oil supply hole 25 so that the oil A is supplied to the main frame 22,
An oil supply groove 26 leading to a bearing portion of the bearing plate 23 is formed. Further, the upper and lower vanes are provided with springs for constantly energizing the upper and lower rollers 18 and 19.

Here, the oil A as the lubricating oil may be an existing oil A such as a mineral oil (mineral oil), an alkylbenzene oil, an ether oil or an ester oil.

The upper and lower cylinders 14 and 15 are provided with upper and lower introduction pipes 28 and 29 for introducing the refrigerant, and upper and lower outlet pipes 30 and 31 for discharging the refrigerant, respectively. And these upper and lower introduction pipes 28, 29
And refrigerant pipes 32, 33,
34 are respectively connected.

The main frame 22 of the rotary compression element 5 has an intermediate pressure chamber 4 communicating with the upper cylinder 14.
The intermediate pressure chamber 45 is defined by the main frame 22 and an upper plate 46 mounted on the upper portion of the main frame 22.

The upper plate 46 is fitted on a bearing portion of the main frame 22 and is locked by a C-ring 46A. Further, 46B is an O-ring.

A high-pressure chamber 50 communicating with the lower cylinder 15 is formed in the bearing plate 23 of the rotary compression element 5. The high-pressure chamber 50 includes a bearing plate 23 and a lower part of the bearing plate 23. And a lower plate 51 attached to the lower plate 51. The high-pressure chamber 50 communicates with the lower outlet pipe 31 of the lower cylinder 15.

The lower plate 51 is fitted on the bearing portion of the bearing plate 23 and is locked by a C-ring 51A. Further, 51B is an O-ring.

Reference numeral 52 denotes a pressure regulating tube for preventing the carbon dioxide gas refrigerant from leaking from between the main plate 22 or the bearing plate 23 and the rotary shaft 4 to increase the pressure inside the sealed container 2, and 53 denotes an intermediate pressure regulating tube. A valve for releasing pressure to the high pressure chamber 50 side, that is, the lower outlet pipe 31 side of the lower cylinder 15 when the pressure of the pressure chamber 45 becomes a predetermined pressure or more, and a base 35 for supporting the closed container 2 And 36 are suction mufflers.

Next, the refrigerant circuit of the two-cylinder rotary compressor 1 will be described with reference to FIGS.

In the case of this two-cylinder rotary compressor 1,
A discharge side refrigerant pipe 32 connected to a lower outlet pipe 31 provided in the lower cylinder 15 of the rotary compressor 1 is connected to a condenser 37, and the condenser 37 and a cooler (evaporator) 3 are connected.
8 is connected to the refrigerant pipe 40 via an expansion valve 39. The cooler 38 and the upper introduction pipe of the upper cylinder 14 of the rotary compressor 1 are connected by a suction side refrigerant pipe 33.

Further, a refrigerant pipe 40 connecting the condenser 37 and the expansion valve 39 is provided with a bypass pipe 43 connected to a subcooler 42 via a bypass expansion valve 41.

The supercooler refrigerant pipe 44 from the subcooler 42 is connected to an upper outlet pipe 30 provided in the upper cylinder 14 of the rotary compressor 1 and a lower inlet pipe 29 of the lower cylinder 15.
And a connection refrigerant pipe 34 for connecting the above and a suction muffler 36.

The connecting refrigerant pipe 34 is connected to the upper outlet pipe 3.
0 and the lower introduction pipe 29 are connected.

The supercooler 42 is formed of a double pipe, in which the refrigerant from the bypass pipe 43 flows inside, and the refrigerant in the refrigerant pipe 40 flows outside. Conversely, the inside may be the refrigerant pipe 40 and the outside may be the bypass pipe 43.

Further, a structure provided in contact with heat conduction may be used.

The refrigerant pipe 40 branched from the bypass pipe 43 is introduced into the subcooler 42, where the refrigerant pipe 40 comes into contact with the bypass pipe 43 after the bypass expansion valve 41 in a heat conductive manner. It is provided. Thereafter, it is connected to the expansion valve 39 described above.

Accordingly, the gas refrigerant of carbon dioxide, which has been compressed by the two-cylinder rotary compressor 1 and has become high temperature, is cooled by the condenser 37, and further cooled by the subcooler 42 to the bypass pipe 43. After replacement, that is, after heat is released, expansion is performed by the expansion valve 39. Thereafter, the gas refrigerant flowing into the cooler 38 and radiating heat here returns to the rotary compressor 1 again from the suction side refrigerant pipe 33.

A part of the refrigerant condensed in the condenser 37 is diverted to the bypass pipe 43 and is adiabatically expanded by the bypass expansion valve 41.
From the heat. The refrigerant collected in the supercooler 42 is mixed with the high-temperature, high-pressure refrigerant in the upper cylinder 14,
The high-temperature, high-pressure refrigerant is cooled and flows into the lower cylinder 15. In addition, the refrigerant after collecting heat in the supercooler 42 is:
The temperature after the discharge of the upper cylinder 14 is lower than the high-pressure refrigerant.

Here, the critical pressure shown in FIG. 6 is about 72 to 73 kgf / cm ² G in the case of a carbon dioxide refrigerant.
Above this critical pressure, that is, in the supercritical region, the carbon dioxide refrigerant is gasified.

In FIG. 6, point A is the refrigerant discharged from the supercooler 42 and the upper cylinder 14 of the compressor and merged into the lower cylinder 15, and point B is the refrigerant discharged from the lower cylinder 15. is there.

Then, the refrigerant at point C is condensed by the condenser 37 and is then adiabatically expanded by the bypass expansion valve 41 with the divided refrigerant. The point D is adiabatically expanded and pressure-reduced refrigerant that has radiated heat, flows into the supercooler 42, and cools the refrigerant at the point C to the point E.

The supercooled refrigerant at the point E is adiabatically expanded by the expansion valve 39 to be in the state at the point F. Thereafter, as indicated by point G, the refrigerant that has collected heat in the cooler 38 and has become high temperature flows into the upper cylinder 14.

As shown at point H, the refrigerant which has been compressed by the upper cylinder 14 and has become high temperature and high pressure
2, the pressure decreases, the refrigerant is used for supercooling, and merges with the refrigerant whose temperature has risen (however, as described above, the high temperature after discharge of the upper cylinder 14 and the lower temperature than the high-pressure refrigerant). The cooled refrigerant flows into the rotary compressor 1.

The rotary compressor 1 having an internal low pressure in the above description is defined as (pressure in the closed vessel 2) <(average pressure of the compression space of the upper cylinder 14) <(average pressure of the compression space of the lower cylinder 15). (The average pressure), the rotary compressor 1 having a pressure relationship of (the average pressure of the compression space of the upper cylinder 14) <(the pressure in the closed vessel 2) < (The average pressure of the compression space of the lower cylinder 15).

The rotary compressor 1 described in detail above includes a home air conditioner, a commercial air conditioner (package air conditioner), an automobile air conditioner, a household refrigerator, a commercial refrigerator, a commercial freezer, a commercial refrigerator, Case,
It is used for vending machines, water heaters and the like.

The rotary compressor 1 has an output of one horsepower.

[0062]

As described above in detail, according to the first aspect of the present invention, the minimum overlap width of the roller and the plate middle is set to be at least 1/3 of the axial thickness of the cylinder, and carbon dioxide is used as the refrigerant. Since the internal pressure is low or intermediate pressure, gas leakage from the overlapping portion of the roller and the plate middle can be prevented as much as possible, and the reduction in volumetric efficiency can be prevented as much as possible, and the size of the rotary compressor can be reduced. it can.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a two-cylinder rotary compressor equipped with the present invention.

FIG. 2 is an enlarged view of a rotary compression element of a rotary compressor equipped with the present invention.

FIG. 3 is a longitudinal sectional view of a rotary compression element unit.

FIG. 4 is a plan view of a rotary compression element unit.

FIG. 5 is a refrigeration circuit diagram using a two-cylinder rotary compressor equipped with the present invention.

FIG. 6 is a Mollier diagram in a refrigeration circuit diagram using a two-cylinder rotary compressor equipped with the present invention.

FIG. 7 is a diagram showing the relationship between the amount of overlap between a roller and a plate middle and the amount of leakage in a two-cylinder rotary compressor equipped with the present invention.

FIG. 8 is a diagram showing a relationship between a cylinder thickness, a shaft pin portion load, and a suction passage resistance in a two-cylinder rotary compressor equipped with the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary compressor 2 Airtight container 5 Rotary compression element 13 Plate middle 14, Upper cylinder 15 Lower cylinder 18 Upper roller 19 Lower roller

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F04C 29/00 F04C 29/00 D (72) Inventor Masaya Tadano 2-5 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. In-house F-term (reference) 3H029 AA05 AA13 AB03 AB05 AB08 BB16 BB33 BB43 BB50 CC04 CC05 CC38

Claims (1)

[Claims] 1. A rotary compression element comprising a cylinder whose both ends are closed, a roller that rotates in the cylinder by a rotation shaft, and a vane that contacts the roller to form a compression space in the cylinder. A plurality of rotary compression elements are housed in a closed container, and a rotary compressor that sucks in carbon dioxide refrigerant, compresses and discharges the rotary compression elements, and partitions the plurality of rotary compression elements. A plate middle for closing one opening of a cylinder of each partitioned rotary compression element, and a minimum overlap width of the partitioned roller and the plate middle of the rotary compression element is defined as an axial thickness of the cylinder. 1/3
A rotary compressor as described above, wherein the inside of the closed vessel is set to an internal low pressure or an intermediate pressure.