WO2009096220A1

WO2009096220A1 - Enclosed compressor

Info

Publication number: WO2009096220A1
Application number: PCT/JP2009/050322
Authority: WO
Inventors: Hajime Sato; Yosiyuki Kimata
Original assignee: Mitsubishi Heavy Industries, Ltd.
Priority date: 2008-01-29
Filing date: 2009-01-13
Publication date: 2009-08-06
Also published as: EP2253849A4; EP2253849A1; JP5276332B2; JP2009180108A; EP2253849B1

Abstract

An enclosed compressor having first and second compressors arranged at the upper and lower portions in an enclosed housing, with the first compressor at the lower part being a rotary compressor. The enclosed compressor is simplified in structure and reduced in cost by reducing the number of parts which construct an oil supply pump and a lower muffler chamber and adapting the parts to be easily worked. In an enclosed compressor (1) having first and second compressors (2, 3) arranged at the upper and lower portions in an enclosed housing (10) with the first compressor (2) at the lower portion being a rotary compressor, a lower bearing (23) of the rotary compressor (2) supports the lower end of a rotating shaft (7) on the center side of the lower bearing, has a bearing boss (50) having at the lower end surface thereof a cylinder chamber (55) of the oil supply pump (14), and is formed in a double-tube shape having an outer tube (51) located on the outer peripheral side of the bearing boss (50) so as to surround the bearing boss. A lid (58) is mounted to the lower end surface of the lower bearing (23) to define the cylinder chamber (55) and the lower muffler chamber (28) of the rotary compressor (2).

Description

Hermetic compressor

The present invention relates to a hermetic compressor in which a first compressor and a second compressor driven by an electric motor are respectively disposed at a lower part and an upper part in a hermetic housing.

A sealed type having a configuration in which an electric motor is installed at a central portion in a hermetic housing, and a first compressor and a second compressor that are rotationally driven via a crankshaft connected to the electric motor are disposed below and above the motor. As a compressor, what is shown to patent document 1 is proposed. The hermetic compressor disclosed in Patent Document 1 is provided with a low-stage rotary compressor constituting the first compressor at the lower part of the electric motor and a high-stage scroll compressor constituting the second compressor at the upper part. This is a hermetic multistage compressor installed. The intermediate-pressure refrigerant gas compressed by the low-stage rotary compressor is discharged into the hermetic housing, and this refrigerant gas is sucked into the high-stage scroll compressor and compressed to a high pressure. Then, it is comprised so that it may send out the exterior of a compressor. Thus, in the hermetic compressor in which the second compressor is disposed in the upper part of the hermetic housing, an oil supply pump is provided at the lower end of the crankshaft in order to lubricate the sliding portion of the second compressor. It is indispensable to supply the second compressor with the lubricating oil filled in the bottom of the hermetic housing by the oil pump.

On the other hand, many sealed compressors configured by disposing a rotary compressor at the lower part of a hermetic housing and having a lower muffler chamber on the lower bearing side have been proposed. As hermetic compressors having a lower muffler chamber on the lower bearing side, there are many two-cylinder rotary compressors (also referred to as twin rotary) as disclosed in

Patent Documents

2 and 3. However, the present invention is not limited to this, and in a single cylinder rotary compressor, a muffler chamber is provided in each of the upper and lower bearings for the purpose of reducing pressure loss at the time of discharge, and the compressed gas is discharged from the upper and lower portions. Is known.

Japanese Patent Laid-Open No. 5-87074 JP 2006-83842 A JP 2007-177624 A

However, in the hermetic compressor in which the first compressor and the second compressor are respectively disposed in the lower and upper portions in the hermetic housing, the first compressor disposed in the lower portion is a rotary compressor. When a discharge valve and a lower muffler chamber and an oil pump for the second compressor are provided around the lower bearing, the configuration around the lower bearing becomes complicated, and the processing man-hours, assembly man-hours and cost increase are It was inevitable. In addition, since it is necessary to secure a mounting allowance for attaching the components of the lower muffler chamber to the lower bearing, there is a problem that the volume of the lower muffler chamber is correspondingly reduced and the function of the discharge muffler is reduced. is doing.

The present invention has been made in view of such circumstances, and first and second compressors are respectively disposed at a lower portion and an upper portion in a hermetic housing, and the lower first compressor is a rotary compressor. Provided is a hermetic compressor capable of reducing the number of parts constituting the oil pump and the lower muffler chamber and facilitating parts processing, simplifying the construction and reducing costs. For the purpose.

In order to solve the above problems, the hermetic compressor of the present invention employs the following means.
That is, the hermetic compressor according to one aspect of the present invention is disposed between the first and second compressors disposed at the lower and upper portions in the hermetic housing, and the first and second compressors. An electric motor, a rotary shaft driven by the electric motor and having both ends connected to the first and second compressors, and a lower end portion of the rotary shaft; A hermetic pump in which the first compressor is constituted by a rotary compressor, and the lower bearing of the rotary compressor is arranged on the center side of the rotary shaft. While having a bearing boss portion that supports the lower end portion and has a cylinder chamber of the oil supply pump provided on the lower end surface, and has an outer cylinder that surrounds the bearing boss portion on the outer peripheral side thereof, a double cylinder shape is provided. A lid on the lower end surface of the lower bearing A lower muffler chamber of the rotary compressor and the cylinder chamber is partitioned and formed by mounting the wood.

According to the above aspect, the double bearing type is provided with the bearing boss portion in which the lower bearing supports the lower end portion of the rotating shaft, the cylinder chamber of the oil supply pump is provided on the lower end surface, and the outer cylinder surrounding the outer periphery thereof. The cylinder chamber and the lower muffler chamber are partitioned and formed by attaching a lid member to the lower end surface of the lower bearing. For this reason, both the cylinder chamber of the oil pump and the lower muffler chamber of the rotary compressor can be partitioned by using a lower cylindrical bearing. As a result, the number of parts can be reduced and parts processing can be facilitated, and the configuration can be simplified and the cost can be reduced. In addition, since the lower muffler chamber can be simply configured by the outer cylinder of the lower bearing having a double cylinder shape, the effective volume can be ensured to the maximum without the need for mounting the lower muffler chamber.

A hermetic compressor according to one aspect of the present invention is the above-described hermetic compressor, wherein the lower end surface of the bearing boss portion and the lower end surface of the outer cylinder are formed on the same plane, and the lower end surface is flat. The cylinder chamber and the lower muffler chamber are partitioned by the lid member.

According to the above aspect, the lower end surface of the bearing boss part and the lower end surface of the outer cylinder are formed on the same plane, and the lower end surface is covered with the flat lid member to form the cylinder chamber and the lower muffler chamber. ing. Therefore, it is possible to process the lower end surface of the bearing boss portion and the outer cylinder and the flat surface processing of the flat lid member attached to the lower end surface in one step. For this reason, the processing man-hour of a lower bearing and a cover member can be reduced, and improvement of productivity and cost reduction can be aimed at.

The hermetic compressor according to one aspect of the present invention is the hermetic compressor according to any one of the above-described hermetic compressors, wherein the oil supply pump is attached to a lower end portion of the rotating shaft and is rotated in the cylinder chamber. And a positive displacement pump that includes a suction port and a discharge port that communicate with the cylinder chamber, and that feeds the lubricating oil to an oil supply hole formed in the rotating shaft.

According to the above aspect, the oil supply pump is mounted on the lower end portion of the rotating shaft and includes the rotor rotated in the cylinder chamber, the suction port and the discharge port communicating with the cylinder chamber, and the lubricating oil is supplied to the rotating shaft. It is comprised with the positive displacement pump which sends out to the oil supply hole drilled in. For this reason, a positive displacement oil supply pump for supplying lubricating oil to the second compressor can be provided by using the lower bearing and the lower end portion of the rotating shaft with a minimum number of components. Therefore, both the lower muffler chamber and the positive displacement oil pump can be configured simply and inexpensively with a minimum number of parts.

A hermetic compressor according to one aspect of the present invention is the above-described hermetic compressor, wherein a discharge port and a discharge valve that discharge compressed gas to the lower muffler chamber are disposed between the oil pump and the shaft of the rotary shaft. The suction port and the discharge port are disposed on the opposite side.

According to the above aspect, the discharge port and the discharge valve for discharging the compressed gas to the lower muffler chamber are arranged on the opposite side to the suction port and the discharge port of the oil supply pump with the axis of the rotating shaft interposed therebetween. Therefore, the space on the side where the discharge port and the discharge valve are disposed in the lower muffler chamber can be made wider than the space on the side where the suction port and the discharge port of the oil supply pump are disposed. For this reason, it is possible to easily install a discharge valve in which an elongated reed valve is generally used, and the oil supply pump and the discharge valve can be accommodated and installed without increasing the size of the lower bearing.

According to the present invention, both the cylinder chamber of the oil supply pump and the lower muffler chamber of the rotary compressor can be defined by using the lower cylindrical bearing. For this reason, the number of parts can be reduced and the parts can be easily processed, and the configuration can be simplified and the cost can be reduced. Since the lower muffler chamber can be simply configured by the outer cylinder of the lower bearing having a double cylinder shape, the effective volume can be secured to the maximum without the need for the mounting cost of the lower muffler chamber.

1 is a longitudinal sectional view of a hermetic compressor according to an embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view of a main part of the hermetic compressor shown in FIG. 1. It is the top view which looked at the lower bearing of the hermetic compressor shown in Drawing 2 from the lower part. FIG. 4 is a cross-sectional view corresponding to aa of the lower bearing shown in FIG. 3. It is a cross-sectional view of the oil supply pump part of the hermetic compressor shown in FIG.

Explanation of symbols

1 hermetic compressor 2 first compressor (2-cylinder rotary compressor)
3 Second compressor (scroll compressor)
4 Electric motor 7 Rotating shaft (Crank shaft)
DESCRIPTION OF SYMBOLS 10 Sealing housing 14 Oil supply pump 16 Oil supply hole 23 Lower bearing 28 Lower muffler chamber 50 Bearing boss part 51 Outer cylinder 52 Discharge port 53 Discharge valve 55 Cylinder chamber 58 Lid member 60 Rotor 62 Intake port 64 Discharge port

An embodiment according to the present invention will be described below with reference to FIGS. 1 to 5.
FIG. 1 is a longitudinal sectional view of a hermetic compressor 1 according to an embodiment of the present invention. In the present embodiment, for convenience, a low-stage two-cylinder rotary compressor that constitutes the first compressor 2 is disposed in the lower portion of the hermetic housing 10, and a high-stage scroll compressor that constitutes the second compressor 3 in the upper portion. The hermetic compressor 1 according to the present invention will be described by taking a hermetic multistage compressor provided with an example as an example. However, the present invention is not limited to this, and the first compressor 2 is a single-cylinder rotary compressor. Further, the second compressor 3 does not need to be a scroll compressor, and may be a compressor of another type.

The hermetic compressor (sealed multistage compressor) 1 includes a hermetic housing 10. The sealed housing 10 includes a cylindrical center housing 10A, an annular bearing bracket 11 provided by welding all around the center housing 10A, a lower housing 10B that seals the lower portion of the center housing 10A, and the bearing bracket 11 The upper housing 10C is provided at the upper portion by welding all around and seals the upper portion of the center housing 10A.

An electric motor 4 including a stator 5 and a rotor 6 is fixedly installed at a substantially central portion in the center housing 10A. A rotating shaft (crankshaft) 7 is integrally coupled to the rotor 6. Below the electric motor 4, a low-stage two-cylinder rotary compressor 2 constituting the first compressor 2 is installed. The two-cylinder rotary compressor 2 includes

cylinder chambers

20A and 20B. The cylinder

main bodies

21A and 21B are fixedly installed in the center housing 10A, and are fixedly installed on the upper part of the cylinder main body 21A and the lower part of the cylinder main body 21B. An upper bearing 22 and a lower bearing 23 for sealing the upper portion of the chamber 20A and the lower portion of the cylinder chamber 20B, an intermediate partition plate 24 interposed between the cylinder body 21A and the cylinder body 21B, the crank portion 7A of the

rotary shaft

7, 7B,

rotors

25A and 25B that rotate on the inner peripheral surfaces of the

cylinder chambers

20A and 20B, blades and blade pressing springs (not shown) that partition the

cylinder chambers

20A and 20B into a suction side and a discharge side It is set as the structure provided with.

The two-cylinder rotary compressor 2 sucks a low-pressure refrigerant gas (working gas) into the

cylinder chambers

20A and 20B via the

suction pipes

26A and 26B, and this refrigerant gas is rotated by the

rotors

25A and 25B to an intermediate pressure. Are compressed into the upper muffler chamber 27 and the lower muffler chamber 28 that are formed vertically using the upper bearing 22 and the lower bearing 23, merge in the upper muffler chamber 27, and then in the center housing 10A. It is configured to exhale. This intermediate-pressure refrigerant gas flows through a gas passage hole (not shown) provided in the rotor 6 of the electric motor 4 and is guided to the upper space of the electric motor 4, and further the high-pressure refrigerant gas constituting the second compressor 3. It is sucked into the stage side scroll compressor 3 and compressed by two stages.

The high-stage scroll compressor 3 constituting the second compressor 3 is provided in the upper housing 10C. The scroll compressor 3 is provided with a bearing 30 that supports a rotating shaft (crankshaft) 7, and a bearing case 31 (also referred to as a frame member or a supporting member) fixedly installed on the upper surface of the bearing bracket 11 via bolts 12. And the spiral wraps 32B and 33B standing on the

end plates

32A and 33A, respectively, and the spiral wraps 32B and 33B are engaged with each other and assembled on the bearing case 31 to constitute a pair of compression chambers 34. A fixed scroll member 32 and an orbiting scroll member 33 are provided.

The scroll compressor 3 further couples the orbiting scroll member 33 and the eccentric pin 7C of the rotating shaft 7 via the drive bush 13 to rotate the orbiting scroll member 33 so as to revolve and drive, and the orbiting scroll member 33. A rotation prevention mechanism 35 that is provided between the bearing case 31 and prevents the rotation of the orbiting scroll member 33 to rotate and revolves, and a discharge reed valve 36 that is provided on the back side of the fixed scroll member 32 and opens and closes the discharge port 32C. A fixed cover so as to surround the discharge reed valve 36 on the back side of the fixed scroll member 32, a discharge cover 38 forming an oil separation chamber 37, and a compressed high-pressure gas connected to the center of the discharge cover 38 Is installed in the oil separation chamber 37 and the discharge pipe 39 for discharging the oil to the outside, and the oil is centrifuged from the compressed gas. Is the oil separation mechanism 40 configured to include a.

The scroll compressor 3 sucks the intermediate-pressure refrigerant gas compressed by the two-cylinder rotary compressor 2 and discharged into the sealed housing 10 into the compression chamber 34. After being compressed to a higher pressure state by a compression operation by revolving turning drive, it is configured to discharge to the oil separation chamber 37 in the discharge cover 38 via the discharge reed valve 36. The high-temperature and high-pressure refrigerant gas is sent to the outside of the hermetic compressor 1, that is, to the refrigeration cycle side through the discharge pipe 39 after the oil in the gas is separated by the oil separation mechanism 40 in the oil separation chamber 37. It has become so.

A positive displacement oil pump 14 is incorporated between the lowermost end of the rotary shaft (crankshaft) 7 and the lower bearing 23 of the low-stage rotary compressor 2. The oil pump 14 pumps up the lubricating oil 15 filled in the bottom of the hermetic housing 10, and through the oil holes 16 provided in the rotary shaft 7, the bearing portions of the two-cylinder rotary compressor 2 and the scroll compressor 3. For example, the lubricating oil 15 is forcibly supplied to a required lubricating portion.

The oil supplied by the oil supply pump 14 and lubricated the scroll compressor 3 and the oil separated by the oil separation mechanism 40 are oil drop holes 41 and 42 provided in the fixed scroll member 32 and the bearing case 31, respectively. , 43, the oil is discharged from an oil discharge pipe 44 connected to the bearing bracket 11 to the bottom of the hermetic housing 10. It is assumed that a pressure reduction mechanism (not shown) is interposed in the oil drain hole 41 from the oil separation mechanism 40.

In the present embodiment, the lower bearing 23, the lower muffler chamber 28, and the oil supply pump 14 described above are configured as follows.
As shown in FIGS. 2 to 4, the lower bearing 23 is provided with a bearing boss portion 50 that supports the shaft end of the rotating shaft (crankshaft) 7 at the center portion, and surrounds the bearing boss portion 50 on the outer periphery thereof. Thus, it is set as the double cylinder shape provided with the outer cylinder 51 with the lower part opened. An annular space formed between the bearing boss portion 50 of the lower bearing 23 and the outer cylinder 51 is configured as a lower muffler chamber 28.

The lower bearing 23 is provided with a discharge port 52 that allows the cylinder chamber 20B and the lower muffler chamber 28 to communicate with each other. The discharge port 52 includes a leaf spring-like reed valve on the lower muffler chamber 28 side. A discharge valve 53 is installed. The lower bearing 23 is fixedly installed on the cylinder body 21 </ b> B by a plurality of bolts 54. A cylinder chamber 55 having a predetermined dimension in the axial direction constituting the oil supply pump 14 is formed concentrically with the rotary shaft 7 on the lower end surface of the bearing boss portion 50. The cylinder chamber 54 is provided with a blade groove 55A extending in the radial direction.

The lower end surface of the bearing boss portion 50 in the lower bearing 23 and the lower end surface of the outer cylinder 51 are formed on the same plane, and the lower end surface includes a thin plate member 56 and a thick plate presser member 57. A flat lid member 58 is fixedly installed via a bolt 59. As a result, the lower muffler chamber 28 and the cylinder chamber 55 are covered and sealed with a common flat lid member 58.

As shown in FIG. 5, the cylinder chamber 55 defined by the lid member 58 is attached to an eccentric portion 7 </ b> D provided at the shaft end of the rotating shaft 7. A rotor 60 that is rotated on the inner peripheral surface is accommodated. A blade 60A that is slidably fitted in a blade groove 55A of the cylinder chamber 55 is integrally provided on the outer periphery of the rotor 60, and partitions the inside of the cylinder chamber 55 into a suction side and a discharge side of the lubricating oil. A suction port 62 communicating with a suction pipe 61 suspended in the lubricant 15 filled in the bottom of the sealed housing 10 is opened on the lubricant suction side of the cylinder chamber 55, and the lubricant discharge side A discharge port 64 communicating with an oil supply hole 16 provided in the rotary shaft 7 is opened through an oil passage 63 provided in the lid member 58.

Thus, an oil supply pump 14 for forcibly supplying the lubricating oil 15 to the two-cylinder rotary compressor 2 and the scroll compressor 3 is configured. The oil passage 63 is provided on the mating surface of the plate member 56 and the plate pressing member 57 constituting the lid member 58 so as to communicate with the discharge port 64 and the oil supply hole 16. The discharge port 52 provided in the lower bearing 23 and the suction port 62, the discharge port 64 and the blade groove 55 </ b> A constituting the oil supply pump 14 provided in the bearing boss 50 are opposite to each other across the axis of the rotating shaft 7. (See FIG. 3). That is, the outer diameter of the bearing boss portion 50 is increased to provide the suction port 62, the discharge port 64, and the blade groove 55A, and the radial space between the outer cylinder 51 and the rotary shaft 7 is reduced. The space between the bearing boss 50 and the outer cylinder 51 on the side where the discharge port 52 on the opposite side is provided across the shaft core can be widened. For this reason, the installation space of the discharge valve 53 comprised by a reed valve can fully be ensured.

With the configuration described above, according to the present embodiment, the following operational effects can be obtained.
The low-temperature and low-pressure refrigerant gas sucked into the

cylinder chambers

20A and 20B of the two-cylinder rotary compressor 2 constituting the first compressor 2 through the

suction pipes

26A and 26B reaches the intermediate pressure by the rotation of the

rotors

25A and 25B. After being compressed, the air is discharged into the upper muffler chamber 27 and the lower muffler chamber 28, and the pulsation is attenuated. The intermediate pressure refrigerant gas is merged in the upper muffler chamber 27 and then discharged into the lower space of the electric motor 4, from which gas passage holes (not shown) provided in the rotor 6 of the electric motor 4, etc. And flows into the upper space of the electric motor 4.

The intermediate-pressure refrigerant gas that has flowed into the upper space of the electric motor 4 passes through a suction gas passage (not shown) formed between the outer surface of the bearing case 31 and the upper surface of the bearing bracket 11 from the center region of the center housing 10A. Then, the air is sucked into the compression chamber 34 formed between the fixed scroll member 32 and the orbiting scroll member 33. The intermediate-pressure refrigerant gas is compressed into a high-temperature and high-pressure state by a compression operation caused by the orbiting scroll member 33 being driven to revolve orbit, and then discharged into the discharge cover 38 from the discharge port 32C via the discharge reed valve 36. It is.

In the above-described two-stage compression process, part of the lubricating oil 15 supplied by the oil supply pump 14 and used for lubrication of the two-cylinder rotary compressor 2 dissolves in the refrigerant gas, and enters the center housing 10A together with the intermediate-pressure refrigerant gas. Vomited. Further, the intermediate pressure refrigerant gas is supplied to the scroll compressor 3 through the oil supply hole 16, lubricates the scroll compressor 3, and then passes through the oil drain holes 43 and 42 and the oil discharge pipe 44 to enter the sealed housing 10. Part of the lubricating oil 15 that flows down to the bottom of the melted. The intermediate pressure refrigerant gas in which the lubricating oil 15 is dissolved in this way is sucked into the scroll compressor 3 while containing the oil and compressed, becomes high-temperature high-pressure gas, and is discharged from the discharge port 32C together with the oil.

The high-temperature and high-pressure compressed gas containing oil is connected to the center of the discharge cover 38 after the oil is centrifuged by a centrifugal oil separation mechanism 40 provided in an oil separation chamber 37 in the discharge cover 38. The discharge pipe 39 is discharged to the refrigeration cycle side. As a result, the oil circulation rate (OCR) of the lubricating oil 15 circulated to the refrigeration cycle side is reduced, the system efficiency is improved, and the occurrence of insufficient lubricating oil in the hermetic compressor 1 is eliminated. The oil separated in the oil separation chamber 37 is depressurized to a low pressure in the oil dropping hole 41 by a pressure reducing mechanism, and then flows down to the bottom in the sealed housing 10 through the oil dropping hole 42 and the oil discharge pipe 44.

In the above-described hermetic compressor 1, the lower muffler chamber 28 into which the intermediate-pressure refrigerant gas compressed in the lower cylinder chamber 20B of the two-cylinder rotary compressor 2 is discharged, the two-cylinder rotary compressor 2, and the scroll compressor 3 The lower bearing 23 provided with the cylinder chamber 55 of the oil pump 14 for supplying the lubricating oil 15 is formed in a double cylinder shape, and the cylinder chamber 55 is provided on the lower end surface of the bearing boss portion 50 formed at the center portion thereof. An annular lower muffler chamber 28 is provided between the bearing boss portion 50 and an outer cylinder 51 formed so as to surround the outer periphery thereof. And the lower muffler chamber 28 and the cylinder chamber 55 are defined by forming the lower end surfaces of the bearing boss portion 50 and the outer cylinder 51 on the same plane and covering the lower end surfaces with a common flat lid member 58. .

For this reason, both the lower muffler chamber 28 and the cylinder chamber 55 can be defined by the double-cylindrical lower bearing 23 and the flat lid member 58. Thereby, the number of components of the lower muffler chamber 28 and the oil pump 14 can be reduced, and the configuration can be simplified and the cost can be reduced.
Since it is possible to process the lower end surface of the bearing boss portion 50 and the outer cylinder 51 and the flat surface processing of the flat lid member 58 attached to the lower end surface in one step, the lower bearing 23 and the lid The number of processing steps for the member 58 (the plate member 56 and the plate pressing member 57) can be reduced, and the productivity can be improved and the cost can be reduced.

Since the lower muffler chamber 28 can be simply configured by the outer cylinder 51 of the lower bearing 23 having a double cylinder shape, it is not necessary to install a lower muffler part as a separate part. it can. As a result, the effective volume of the lower muffler chamber 28 can be ensured to the maximum, and the effect of reducing discharge pulsation can be enhanced.

By providing a rotor 60 that is mounted on an eccentric portion 7D provided at the lower end of the rotary shaft 7 and rotated in the cylinder chamber 55, and a suction port 62 and a discharge port 64 that communicate with the cylinder chamber 55, Since the positive displacement oil pump 14 is configured to send the lubricating oil 15 to the oil hole 16 formed in the rotating shaft 7, the minimum components using the lower bearing 23 and the lower end of the rotating shaft 7 are used. Thus, the oil supply pump 14 to the second compressor (scroll compressor) 3 disposed in the upper part of the hermetic housing 10 can be configured. Thereby, both the lower muffler chamber 28 and the positive displacement oil pump 14 can be configured simply and inexpensively with a minimum number of parts.

A discharge port 52 and a discharge valve 53 for discharging intermediate pressure compressed gas compressed in the lower cylinder chamber 20 </ b> B into the lower muffler chamber 28, and a suction port 62 and a discharge port 64 of the oil supply pump 14 across the axis of the rotary shaft 7. It is arrange | positioned on the opposite side. For this reason, the space on the side where the discharge port 52 and the discharge valve 53 are disposed in the lower muffler chamber 28 is made wider than the space on the side where the suction port 62 and the discharge port 63 of the fuel pump 14 are disposed. Can do. As a result, it is possible to easily install the discharge valve 53 in which an elongated reed valve is generally used, and the oil supply pump 14 and the discharge valve 53 can be accommodated without increasing the size of the lower bearing 23.

In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, the hermetic compressor 1 of the present invention is not limited to one using an HFC refrigerant such as R410A as a working gas, but can be similarly applied to one using a CO2 refrigerant or another refrigerant. In particular, when a high-density CO 2 refrigerant is used, the first compressor 2 disposed in the lower portion of the hermetic housing 10 may be a single-cylinder rotary compressor. Even in this case, providing the lower muffler chamber 28 in the lower bearing 23 is effective in reducing the pressure loss during discharge.
Moreover, as the oil supply pump 14, not only the thing of the said embodiment but of course, you may use the positive displacement pump of another type.

Claims

First and second compressors disposed in the lower and upper portions of the hermetic housing, an electric motor disposed between the first and second compressors, and driven by the electric motor, both ends thereof are respectively A rotating shaft connected to the first and second compressors, and an oil supply pump that is provided at a lower end of the rotating shaft and supplies lubricating oil filled in a sealed housing to the second compressor, In the hermetic compressor in which the first compressor is constituted by a rotary compressor,
The lower bearing of the rotary compressor includes a bearing boss portion that supports a lower end portion of the rotating shaft on the center side and a cylinder chamber of the oil pump on the lower end surface, and the bearing boss portion on the outer peripheral side thereof. The cylinder chamber and the lower muffler chamber of the rotary compressor are sectioned by mounting a lid member on the lower end surface of the lower bearing, with a double cylinder shape having an outer cylinder to surround. Hermetic compressor.
A lower end surface of the bearing boss portion and a lower end surface of the outer cylinder are formed on the same plane, and the lower end surface is covered with a flat plate-like lid member to define the cylinder chamber and the lower muffler chamber. The hermetic compressor according to claim 1.
The oil supply pump is provided at a lower end portion of the rotating shaft and includes a rotor that is rotated in the cylinder chamber, and a suction port and a discharge port that are communicated with the cylinder chamber, and the lubricating oil is supplied to the rotating shaft. The hermetic compressor according to claim 1, wherein the hermetic compressor is constituted by a positive displacement pump that feeds through a provided oil hole.
The discharge port and discharge valve for discharging compressed gas to the lower muffler chamber are disposed on the opposite side of the suction port and the discharge port of the oil pump with the shaft core of the rotating shaft interposed therebetween. Hermetic compressor.