JP3291472B2 - Rotary compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rotary compressor using natural refrigerant, particularly carbon dioxide (CO ₂ ).

[0002]

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, A first oil supply passage for supplying oil from an oil reservoir to each sliding portion is provided on the rotating shaft; and a bearing for closing the opening of the cylinder. Are disclosed.

[0003]

When carbon dioxide is used as a refrigerant in a rotary compressor having the above-described structure, the refrigerant pressure reaches about 100 kg / cm ² G on the high pressure side and reaches about 100 kg / cm ² G on the high pressure side. It becomes about 30 kg / cm ² G.

[0004] Such a pressure difference causes a problem that the vane is pushed up and the vane flies, thereby lowering the compression efficiency.

Further, when carbon dioxide is used as the refrigerant, there is a problem in strength unless the inside of the closed vessel of the rotary compressor is set to an internal low pressure or an internal intermediate pressure.

For this reason, the internal pressure is set to the internal low pressure or the internal intermediate pressure. However, in the case of a rotary compressor having an internal low pressure or an internal intermediate pressure using a carbon dioxide refrigerant, the internal pressure of the compression chamber is higher than the internal pressure of the closed vessel. There was a problem that it was difficult to supply the oil inside the sealed container to the space inside the roller by the centrifugal force of the rotating shaft.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and it is an object of the present invention to prevent a vane from flying as much as possible and to supply oil to a roller inner space even in a compressor using carbon dioxide as a refrigerant. And

[0008]

As means for achieving the above object, a cylinder having both ends closed, a roller attached to a rotating shaft and rotating in the cylinder by the rotating shaft, A vane that forms a compression space by contacting the cylinder, a cylinder, a roller, and a sealed container that houses a rotary compression element composed of a vane. A pressure chamber from which the refrigerant compressed in the space is discharged, a vane rear chamber formed on the back side of the vane, and a communication between the vane rear chamber and the pressure chamber for pressure regulation and separation by the pressure chamber. A pressure regulating passage for introducing the extracted oil into the vane rear chamber, a roller inner space located near the roller and the rotating shaft, and a communication between the vane rear chamber and the roller inner space. And a communicating path that provides a rotary compressor the pressure regulating passage formed in the cylinder center side of the communication passage.

For this reason, substantially the same pressure as the high pressure side of the compression space is applied to the vane rear chamber via the pressure chamber, and the vane can be pushed out to the roller side by the pressure of the vane rear chamber. Further, the oil that has flowed into the vane rear chamber through the pressure adjustment passage is introduced into the roller inside space through the communication passage. Also, when the vane is projected, the oil can be introduced into the vane rear chamber, and when the vane is retracted, the oil can be introduced into the roller inner space. That is, the vane and the vane rear chamber can be used as a pump for introducing oil.

Therefore, even with a rotary compressor using carbon dioxide refrigerant, the vane can be pressed against the roller and oil can be supplied to the space inside the roller.

[0011]

[0012]

[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 equipped with the present invention, FIG. 2 is an enlarged view of a vane portion, and FIG.
Is a refrigeration circuit diagram using a two-cylinder rotary compressor equipped with the present invention, and FIG. 4 is a Mollier diagram in a refrigeration circuit diagram using a two-cylinder rotary compressor equipped with the present invention.

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.

The hermetically closed container 2 has an oil reservoir at its lower part, and comprises a container 2A for accommodating the electric element 3 and the rotary compression element 5, and a sealing lid 2B for sealing the container 2A. A terminal terminal (wiring is omitted) 6 for supplying electric power to the electric element 3 is attached to the sealing lid 2B.

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 may be used.

The rotary compression element 5 includes 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 4 inside the upper and lower cylinders 14 and 15. Vertical eccentric part 16, 1
And upper and lower vanes (not shown) which contact the upper and lower rollers 18 and 19 to partition the inside of the upper and lower cylinders 14 and 15 into a high pressure side and a low pressure side. A main frame 22, a bearing plate 23 for closing the upper and lower openings of the cylinders 14, 15 and allowing rotation of the rotary shaft 4, an upper plate 58 for forming an intermediate pressure chamber 60 together with the main frame 22, A lower plate 59 for forming the high pressure chamber 61 together with the bearing plate 23 is formed.

Further, a roller inner space 28 is defined by the rotating shaft 4 for rotating the upper and lower rollers 18 and 19, the roller inner surface, the main frame 22, and the bearing plate 23.

The upper plate 58, the main frame 22, the upper cylinder 14, the plate middle 13, the lower cylinder 15, the bearing plate 23, the lower plate 5
9 are connected by bolts 24 in this order.

Further, 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 vane 20 and the lower vane are provided with an upper spring 27 and a lower spring (not shown) which are urging means for constantly urging the upper and lower rollers 18 and 19.

Here, the oil A as the lubricating oil may be an existing oil 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 an upper inlet pipe (not shown) and a lower inlet pipe 29 for introducing a refrigerant, and an upper and lower outlet pipe 3 for discharging the refrigerant.
0 and 31 are provided respectively. Refrigerant pipes 32, 33 and 34 are connected to the upper and lower introduction pipes 29 and the upper and lower outlet pipes 30 and 31, respectively.

Reference numeral 35 denotes a pedestal for supporting the closed container 2, reference numeral 36 denotes a suction muffler, and reference numeral 51 denotes an intermediate pressure chamber 60.
Is a valve for releasing pressure to the high pressure chamber 61 side, that is, to the lower outlet pipe 31 side of the lower cylinder 15 when the pressure exceeds a predetermined pressure.

A recess is formed on the upper surface of the main frame 22 of the rotary compression element 5, and an upper plate 58 is provided above the main frame 22 so as to close the recess. The main frame 22
A gasket 63 made of NBR (acrylonitrile butadiene rubber) is provided between
Is interposed. Thereby, as described above, the intermediate pressure chamber 60 is formed, and the discharge side of the compression space and the connection refrigerant pipe 3 are formed.
4 is communicated.

The NBR is an oil-resistant rubber obtained by emulsion copolymerization of acrylonitrile and butadiene.

The main frame 22 rotatably supports the rotary shaft 4, and the upper plate 58 has a hole through which a bearing portion of the main frame 22 is inserted.

Then, with the bearing portion of the main frame 22 inserted through the hole of the upper plate 58, a sealing member 62 such as an O-ring is located between the bearing portion of the main frame 22 and the upper plate 58. Becomes Further, in this state, the upper plate 58 is locked to the main frame 22 by a fitting member such as a C-ring 65.

A recess is formed on the lower surface of the bearing plate 23 of the rotary compression element 5, and a lower plate 59 is provided below the bearing plate 23 so as to close the recess. I have. An NBR is provided between the bearing plate 23 and the lower plate 59.
A gasket 67 made of (acrylonitrile butadiene rubber) is interposed. Thereby, as described above, the high pressure chamber 61 is formed, and the discharge side of the compression space and the discharge side refrigerant pipe 32 communicate with each other.

The bearing plate 23 rotatably supports the rotary shaft 4, and the lower plate 59 is formed with a hole through which a bearing portion of the bearing plate 23 is inserted.

Then, with the bearing portion of the bearing plate 23 inserted through the hole of the lower plate 59, a gap is formed between the bearing portion of the bearing plate 23 and the lower plate 59.
A sealing material 69 such as an O-ring is located. Further, in this state, the lower plate 59 is locked to the bearing plate 23 by a fitting member such as a C-ring 70.

The upper and lower cylinders 14 and 15 have
The upper vane 20 and the lower vane are upper and lower rollers 18, 19
An upper vane rear chamber 47 and a lower vane rear chamber (not shown) for reciprocating sliding along are formed. And
The spring 27 is located in the upper vane rear chamber 47.

Further, the upper vane rear chamber 47 communicates with the intermediate pressure chamber 60 via a pressure regulating passage 49 and communicates with the roller inner space 28 via a communication passage 50. The pressure adjustment passage 49 of the upper vane rear chamber 47 is
It is open to the center side of the upper and lower cylinders 14 and 15 from the communication passage 50.

Accordingly, when the spring 27 for pressing the upper vane 20 against the upper roller 18 is fully extended, the pressure regulating passage 49 and the communication passage 50 are open to the upper vane rear chamber 47, and the spring 27 is contracted. In this case, first, the pressure adjustment passage 49 opened to the center of the upper and lower cylinders 14 and 15 is closed by the upper vane 20. The oil A accumulated in the upper vane rear chamber 47 between the pressure adjustment passage 49 and the communication passage 50 is supplied to the roller inner space 28 through the communication passage 50.

That is, the upper vane rear chamber 47 and the upper vane 20 function as a pump for introducing oil.

Further, the upper vane rear chamber 47 can push the upper vane 20 toward the upper roller 18 with a pressure equal to or higher than the high pressure side of the compression space. As a result, vane flying can be prevented as much as possible.

Therefore, since vane jumping can be prevented as much as possible, the sealing performance between the high pressure side and the low pressure side of the compression space is improved, the compression efficiency can be improved, and the oil flowing into the roller inner space 28 can be improved. A can be reliably supplied, and the reliability of the rotary compressor 1 can be improved.

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

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

Further, the 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 connecting the suction pipe and the suction muffler 36.

Incidentally, the subcooler 42 is constituted by 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.

Furthermore, 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, and the supercooler 42 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 the replacement, that is, the heat is released, the expansion valve 39 expands. 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, adiabatically expanded by the bypass expansion valve 41, and then cooled by the subcooler 42.
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 high temperature after the discharge of the upper cylinder 14 is lower than the high pressure refrigerant.

Here, the critical pressure shown in FIG. 4 is about 72 to 73 kgf / cm ² G in the case of carbon dioxide refrigerant,
Above the critical pressure and above the critical temperature in the supercritical region, the carbon dioxide refrigerant is gasified.

In FIG. 4, point A is the refrigerant discharged from the supercooler 42 and the compressor 14 from the upper cylinder 14 and merged into the lower cylinder 15. Point B is the refrigerant discharged from the lower cylinder 15. is there.

The refrigerant at point C is condensed in the condenser 37 and then agitated, and adiabatically expanded by the bypass expansion valve 41. 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 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 has an internal low pressure or an internal intermediate pressure because carbon dioxide is used as a refrigerant. And the rotary compressor 1 with the internal low pressure is:
The rotary compressor 1 has a pressure relationship of (pressure in the closed vessel 2) <(average pressure in the compression space of the upper cylinder 14) <(average pressure in the compression space of the lower cylinder 15), and has an internal intermediate pressure. The rotary compressor 1 is a rotary compressor 1 having a pressure relationship of (average pressure in the compression space of the upper cylinder 14) <(pressure in the closed vessel 2) <(average pressure in the compression space of the lower cylinder 15). It is.

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 home refrigerator, a commercial refrigerator, a commercial freezer, a commercial refrigerator, a showcase, and the like. It is used for.

[0055]

As described above in detail, according to the present invention, a pressure equal to or higher than the high pressure side of the compression space is applied to the vane rear chamber via the pressure chamber, and the vane is moved to the roller side by the pressure of the vane rear chamber. Can be extruded. Further, the oil that has flowed into the vane rear chamber through the pressure adjustment passage is introduced into the roller inside space through the communication passage.

Therefore, vane fly can be prevented as much as possible, so that the sealing performance on the high pressure side and the low pressure side of the compression space can be improved, the compression efficiency can be improved, and oil can be transferred to the roller inner space. The supply can be performed reliably, and the reliability of the rotary compressor can be improved.

Further, since the pressure adjustment passage is formed closer to the center of the cylinder than the communication passage, oil can be introduced into the vane rear chamber when the vane projects, and can be introduced into the roller inner space when the vane is retracted. That is, the vane and the vane rear chamber can be used as a pump for introducing oil.

[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 vane portion.

FIG. 3 is a refrigeration circuit diagram using a two-cylinder rotary compressor equipped with the present invention.

FIG. 4 is a Mollier diagram in a refrigeration circuit diagram using a two-cylinder rotary compressor equipped with the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 2 cylinder rotary compressor 2 airtight container 3 electric element 4 rotary shaft 5 rotary compression element 14 upper cylinder 15 lower cylinder 18 upper roller 19 lower roller 20 upper vane 22 main frame 23 bearing plate 27 biasing means (spring) 28 Roller inner space 32 Discharge side refrigerant pipe 34 Connection refrigerant pipe 47 Upper vane rear chamber 49 Pressure regulating passage 50 Communication passage 60 Intermediate pressure chamber

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-247065 (JP, A) JP-A-6-346878 (JP, A) JP-A 9-101063 (JP, A) JP-A 9-1998 151847 (JP, A) Patent 2507047 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 1/04 F25B 1/00 F04C 18/356 F04C 23/00

Claims (1)

(57) [Claims] 1. A cylinder having both ends closed, a roller attached to a rotating shaft and rotating in the cylinder by the rotating shaft, and a vane forming a compression space by contacting the roller. In a rotary compressor using carbon dioxide as a refrigerant, a pressure chamber in which a refrigerant compressed in the compression space is discharged, and A vane rear chamber formed on the rear side of the vane;
When the pressure is adjusted by connecting the vane rear chamber and the pressure chamber,
In both cases, oil separated in the pressure chamber is introduced into the chamber behind the vane
A pressure regulating passage to the roller interior space located near the rotary shaft and the roller, and a communication passage for communicating the vane rear chamber and the roller inner space, the communicating said pressure regulating passage
A circuit formed at the center of the cylinder from the passage.
Roller compressor .