EP3410039A1

EP3410039A1 - Hermetically sealed compressor

Info

Publication number: EP3410039A1
Application number: EP17820073.9A
Authority: EP
Inventors: Youhei Hotta; Yoshiyuki Kimata; Hajime Sato; Toshiyuki Goto
Original assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Current assignee: Mitsubishi Heavy Industries Thermal Systems Ltd
Priority date: 2016-06-29
Filing date: 2017-06-23
Publication date: 2018-12-05
Also published as: EP3410039A4; WO2018003716A1; JP2018004129A

Abstract

A hermetic compressor to which an accumulator and an oil tank are provided, wherein the manufacturing cost and size are reduced. A hermetic compressor (1), provided with: a hermetically sealed casing (2); a compression mechanism (3, 4) and a motor (5) for driving the compression mechanism (3, 4), housed in the hermetically sealed casing (2); and an exterior tank (11) adjacently provided on the outside of the hermetically sealed casing (2). An accumulator chamber (16) and an oil storage chamber (17) are formed as separate chambers inside the exterior tank (11). The accumulator chamber (16) is disposed on the inner peripheral side and the oil storage chamber (17) is disposed on the outer peripheral side.

Description

Technical Field

The present invention relates to a hermetic compressor which compresses a refrigerant in a refrigerating cycle, and particularly relates to a hermetic compressor in which an electric motor and a compression mechanism are accommodated inside a hermetically sealed casing, and in which an accumulator and an oil tank are installed outside the hermetically sealed casing.

Background Art

As disclosed in Fig. 1 of PTL 1, in some hermetic compressors which are connected during a refrigerating cycle so as to compress a refrigerant, an accumulator and an oil tank are jointly installed separate from a hermetically sealed casing forming a main body thereof. The accumulator is a tank-like member that performs gas-liquid separation and filtration of a suctioned refrigerant. The oil tank stores a refrigerant oil to be supplied to a compression mechanism.
An indoor air conditioner has a layout as follows. The hermetic compressor is vertically installed inside an outdoor unit disposed outdoor. The accumulator and the oil tank are combined with each other in the hermetically sealed casing via fixing means such as a bracket and a band.

Citation List

Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No. 6-323695

Summary of Invention

Technical Problem

However, as described above, the accumulator and the oil tank are separately and jointly installed in the hermetically sealed casing of the hermetic compressor. Accordingly, each dedicated fixing bracket is required for both of these. As a result, a plurality of welding portions has to be welded to the hermetically sealed casing, thereby causing a problem in that manufacturing cost of the hermetic compressor increases.
In addition, the accumulator and the oil tank are installed adjacent to a periphery of the hermetic compressor. Consequently, a size of the hermetic compressor serving as a unit increases, and an occupied area inside an outdoor unit increases, thereby causing a problem in that and other parts. There is a problem that a degraded layout is designed when both of these are installed together with other components.
Furthermore, as another problem, a liquid-phase refrigerant subjected to gas-liquid separation in the accumulator is less likely to vaporize. Accordingly, it is necessary to allow the accumulator to have predetermined capacity so that the liquid refrigerant does not overflow. This inevitably increases the capacity of the accumulator, and thus, the size of the hermetic compressor tends to further increase.
The present invention is made in order to solve these problems, and an object thereof is to provide a hermetic compressor in which an accumulator and an oil tank are jointly installed, and in which manufacturing cost can be reduced and a compact structure can be achieved.

Solution to Problem

According to the present invention, there is provided a hermetic compressor including a hermetically sealed casing, a compression mechanism unit and an electric motor for driving the compression mechanism unit which are accommodated inside the hermetically sealed casing, and an external tank jointly installed outside the hermetically sealed casing. An accumulator chamber and an oil storage chamber are formed as each separate chamber inside the external tank.
According to the hermetic compressor having the above-described configuration, the accumulator chamber and the oil storage chamber are integrally disposed inside the external tank jointly installed in the hermetically sealed casing. Accordingly, unlike the related art, an accumulator tank and an oil tank may not be respectively and independently installed outside the hermetically sealed casing. Therefore, it is no longer necessary to dispose and weld a plurality of fixing means to the hermetically sealed casing. Accordingly, it is possible to reduce the manufacturing cost of the hermetic compressor by reducing the number of components and welding locations.
Moreover, there is provided only one tank member jointly installed in the hermetically sealed casing. Accordingly, compared to a case where two tank members are jointly installed around the hermetically sealed casing, a dead space between the tanks is reduced, thereby enabling the hermetic compressor to have a compact structure.
Furthermore, the accumulator chamber and the oil storage chamber are adjacent to each other inside the external tank. Accordingly, heat of a refrigerant oil stored in the oil storage chamber is transferred to a liquid refrigerant stored inside the accumulator chamber. Therefore, it is possible to promote vaporization of the liquid refrigerant. Thus, storage capacity of the liquid refrigerant in the accumulator chamber is reduced so as to miniaturize the accumulator chamber and the external tank. This advantageous point can contribute to the compact structure of the hermetic compressor.
Inside the external tank, the accumulator chamber may be disposed on an inner peripheral side, and the oil storage chamber may be disposed on an outer peripheral side. In this manner, a periphery of the accumulator chamber can be surrounded by the oil storage chamber, and the heat of the refrigerant oil can further promote the vaporization of the liquid refrigerant inside the accumulator chamber.
As described above, in a case where the accumulator chamber is disposed on the inner peripheral side and the oil storage chamber is disposed on the outer peripheral side, it is preferable that a bottom portion of the accumulator chamber is separated upward from a bottom portion of the oil storage chamber. In this manner, not only the periphery of the accumulator chamber but also the bottom portion of the accumulator chamber is located adjacent to the oil storage chamber. Therefore, it is possible to further promote the vaporization of the liquid refrigerant in the accumulator chamber.
Inside the external tank, the accumulator chamber and the oil storage chamber may be disposed so as to be juxtaposed with each other in an axial direction. According to this configuration, an outer diameter of the external tank can be reduced. Therefore, the hermetic compressor can have the more compact structure.

Advantageous Effects of Invention

As described above, according to the hermetic compressor of the present invention, in the hermetic compressor where the accumulator and the oil tank are jointly installed, the manufacturing cost can be reduced, and the compact structure can be achieved.

Brief Description of Drawings

Fig. 1 is a longitudinal sectional view of a hermetic compressor which illustrates a first embodiment according to the present invention.
Fig. 2 is a plan view of the hermetic compressor illustrated in Fig. 1.
Fig. 3 is a longitudinal sectional view of a hermetic compressor which illustrates a second embodiment according to the present invention.
Fig. 4 is a plan view of the hermetic compressor illustrated in Fig. 3.

Description of Embodiments

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

[First Embodiment]

Fig. 1 is a longitudinal sectional view of a hermetic compressor which illustrates a first embodiment according to the present invention. Fig. 2 is a plan view. A hermetic compressor 1 is used for an indoor air conditioner, for example. However, the hermetic compressor 1 may be used for a cooler (centrifugal chiller) or a heat pump water heater.
For example, the hermetic compressor 1 includes a hermetically sealed casing 2 formed in a cylindrical tank shape disposed so that an axial direction thereof is vertically oriented. A rotary compression mechanism 3 and a scroll compression mechanism 4 which respectively configure compression mechanism units are installed in a lower portion and an upper portion inside the hermetically sealed casing 2. An electric motor 5 is installed in an intermediate portion thereof. A main shaft 6 of the electric motor 5 vertically extends, and axially passing through the rotary compression mechanism 3 and the scroll compression mechanism 4. The vertically installed two compression mechanism units 3 and 4 are simultaneously driven by the electric motor 5.
A stand bracket 8 for erecting the hermetic compressor 1 on an inner bottom surface of an outdoor unit (not illustrated) is fixed to a bottom portion of the hermetically sealed casing 2. In addition, a refrigerant suction pipe 9 connected to a suction side of the rotary compression mechanism 3 is disposed on a lower side surface of the hermetically sealed casing 2. A refrigerant discharge pipe 10 connected to a discharge side of the scroll compression mechanism 4 is disposed in a top portion of the hermetically sealed casing 2. The above-described configuration is well-known. As the compression mechanism unit, it is not always necessary to combine both the rotary compression mechanism 3 and the scroll compression mechanism 4 with each other, and only one of these may be provided. Alternatively, two compression mechanism units having the same type may be provided.
An external tank 11 is jointly installed outside the hermetically sealed casing 2. Similar to the hermetically sealed casing 2, the external tank 11 is a cylindrical tank disposed so that the axial direction is vertically oriented. For example, the external tank 11 has an outer diameter substantially the same as that of the hermetically sealed casing 2, and a length in an axial direction is shorter than that of the hermetically sealed casing 2. The external tank 11 is configured to include a shell plate 11a forming an intermediate portion, and an upper end plate 11b and a lower end plate 11c which are respectively fixed to an upper portion and a lower portion thereof.
In addition, an internal tank 12 is accommodated inside the external tank 11. Similar to the external tank 11, the internal tank 12 is configured to include a shell plate 12a forming an intermediate portion, and an upper end plate 12b and a lower end plate 12c which are respectively fixed to an upper portion and a lower portion thereof.
As illustrated in Figs. 1 and 2, an outer peripheral surface of the external tank 11 (shell plate 11a) is attached to a tank attachment bracket 14 fixed to an outer surface intermediate portion of the hermetically sealed casing 2 by means of welding. The external tank 11 is held by a metal band 15 whose both ends are locked by the tank attachment bracket 14, and is fixed so as to be combined with the hermetically sealed casing 2.
The accumulator chamber 16 and the oil storage chamber 17 are formed as each separate chamber inside the external tank 11. Specifically, an inner space of the internal tank 12 functions as the accumulator chamber 16, and a space between the external tank 11 and the internal tank 12 serves as the oil storage chamber 17. That is, inside the external tank 11, the accumulator chamber 16 is disposed on an inner peripheral side, and the oil storage chamber 17 is disposed on an outer peripheral side.
The upper end plate 12b of the internal tank 12 is separated downward from the upper end plate 11b of the external tank 11. Accordingly, the top portion of the accumulator chamber 16 is separated downward from the top portion of the oil storage chamber 17. Similarly, the lower end plate 12c of the internal tank 12 is separated upward from the lower end plate 11c of the external tank 11. Accordingly, the bottom portion of the accumulator chamber 16 is separated upward from the bottom portion of the oil storage chamber 17.
A refrigerant supply pipe 20 communicating with the inside of the accumulator chamber 16 is disposed so as to penetrate the upper end plate 11b of the external tank 11 and the upper end plate 12b of the internal tank 12, and a refrigerant supply pipe extending from an evaporator of an indoor air conditioner (not illustrated) is connected to an outer end portion thereof. A baffle plate 21 which projects upward and around which a plurality of notches 21a are disposed is installed above the inside of the internal tank 12.
A vaporized refrigerant suction pipe 22 is disposed inside the internal tank 12 along a central axis of the tank, and an upper end portion thereof is separated downward from the baffle plate 21 at a predetermined interval. The lower end portion of the vaporized refrigerant suction pipe 22 penetrates the lower end plate 12c of the internal tank 12 and the lower end plate 11c of the external tank 11. The lower end portion of the vaporized refrigerant suction pipe 22 and the refrigerant suction pipe 9 of the hermetic compressor 1 are connected to each other by an external connection pipe 23. The internal tank 12 is coaxially fixed to the inside of the external tank 11 by the refrigerant supply pipe 20 and the vaporized refrigerant suction pipe 22 which serve as support members.
The top portion of the external tank 11 and the intermediate portion of the hermetically sealed casing 2 are connected to each other by a pressure equalizing pipe 25, and the bottom portion of the external tank 11 and the bottom portion of the hermetically sealed casing 2 are connected to each other by an oil supply pipe 26. Furthermore, an oil recirculating pipe 27 is connected to the intermediate portion of the external tank 11.
If the electric motor 5 of the hermetic compressor 1 configured as above is operated, the main shaft 6 is rotated, and the rotary compression mechanism 3 and the scroll compression mechanism 4 are simultaneously driven.
In this manner, a gas-liquid mixed refrigerant of a gas-phase refrigerant vaporized in an evaporator (not illustrated) and a liquid-phase refrigerant not vaporized in the evaporator flows from the refrigerant supply pipe 20 into the accumulator chamber 16 flows.
The gas-liquid mixed refrigerant flows down onto the baffle plate 21, and further flows down from the notch 21a around the baffle plate 21. Only a liquid-phase refrigerant R of the gas-liquid mixed refrigerant is stored inside the accumulator chamber 16. A storage amount of the liquid refrigerant R is measured by a sensor (not illustrated), and a liquid level thereof is always adjusted to a predetermined range.
In addition, the gas-phase refrigerant contained inside the accumulator chamber 16 is suctioned from an upper end opening portion of the vaporized refrigerant suction pipe 22 protruding upward of the liquid level of the liquid refrigerant R, and is suctioned into the rotary compression mechanism 3 through the external connection pipe 23 and the refrigerant suction pipe 9. In this way, only the gas-phase refrigerant contained inside the accumulator chamber 16 is separated and suctioned into the rotary compression mechanism 3. Therefore, liquid compression in the rotary compression mechanism 3 is prevented.
In the rotary compression mechanism 3, the gas-phase refrigerant is compressed to reach intermediate pressure, and is discharged into the hermetically sealed casing 2. The refrigerant compressed to reach the intermediate pressure passes through the electric motor 5, and is cooled. Thereafter, the refrigerant is suctioned and compressed by the scroll compression mechanism 4, and is changed into a high pressure refrigerant. The high pressure refrigerant is discharged from the refrigerant discharge pipe 10, and is supplied to a condenser through an oil separator of an indoor air conditioner (not illustrated). The refrigerant oil contained in the high pressure refrigerant is separated in the oil separator. The separated refrigerant oil is circulated again from the oil recirculating pipe 27 to the oil storage chamber 17, and is stored inside the oil storage chamber 17.
A refrigerant oil O stored in the oil storage chamber 17 is supplied into the hermetically sealed casing 2 through the oil supply pipe 26, and is used in lubricating bearing portions of the rotary compression mechanism 3, the scroll compression mechanism 4, and the main shaft 6. In this case, the intermediate pressure between the rotary compression mechanism 3 and the scroll compression mechanism 4 inside the hermetically sealed casing 2 is applied to the oil storage chamber 17 through the pressure equalizing pipe 25. In this manner, the refrigerant oil O stored in the oil storage chamber 17 is smoothly supplied into the hermetically sealed casing 2.
As described above, the hermetic compressor 1 includes the hermetically sealed casing 2, the compression mechanism units 3 and 4 accommodated inside the hermetically sealed casing 2, the electric motor 5 for driving the compression mechanism units 3 and 4 which are accommodated inside the hermetically sealed casing 2, and the external tank 11 jointly installed outside the hermetically sealed casing 2. The accumulator chamber 16 and the oil storage chamber 17 are formed as each separate chamber inside the external tank 11.
According to the above-described configuration, the accumulator chamber 16 and the oil storage chamber 17 are integrally disposed inside the external tank 11 jointly installed in the hermetically sealed casing 2. Accordingly, unlike the related art, the accumulator tanks and the oil tank may not be respectively and individually installed outside the hermetically sealed casing 2. Therefore, as fixing means disposed in the hermetically sealed casing 2, only one tank attachment bracket 14 may be used. Therefore, unlike the related art, it is no longer necessary to dispose and weld a plurality of the fixing means to the hermetically sealed casing 2. Accordingly, it is possible to reduce the manufacturing cost of the hermetic compressor 1 by reducing the number of components and welding locations.
Moreover, only one external tank 11 is jointly installed in the hermetically sealed casing 2. Compared to a case where two tank members are jointly installed around the hermetically sealed casing 2 as in the related art, it is possible to reduce a dead space formed between the tanks having a circular cross section, thereby enabling the overall hermetic compressor 1 to have a compact shape. In this manner, an occupied floor area inside an outdoor unit (not illustrated) is reduced. Therefore, it is possible to improve the layout when installed together with other components.
Furthermore, the accumulator chamber 16 and the oil storage chamber 17 are adjacent to each other inside the external tank 11. Accordingly, the heat of the refrigerant oil O stored in the oil storage chamber 17 is transferred to the liquid refrigerant R stored inside the accumulator chamber 16. Therefore, it is possible to promote the vaporization of the liquid refrigerant R, and thus, the storage capacity of the liquid refrigerant R in the accumulator chamber 16 is reduced. The accumulator chamber 16 (internal tank 12) and the external tank 11 are miniaturized. This advantageous point can contribute to the compact structure of the hermetic compressor 1.
In particular, according to the present embodiment, inside the external tank 11, the accumulator chamber 16 is disposed on the inner peripheral side, and the oil storage chamber 17 is disposed on the outer peripheral side, respectively. Moreover, the lower end plate 12c forming the bottom portion of the accumulator chamber 16 is separated upward from the lower end plate 11c forming the bottom portion of the oil storage chamber 17. Accordingly, the periphery and the bottom portion of the accumulator chamber 16 are surrounded with the oil storage chamber 17. Therefore, a vaporization operation of the liquid refrigerant R inside the accumulator chamber 16 can be further promoted by the heat of the refrigerant oil O.

[Second Embodiment]

Fig. 3 is a longitudinal sectional view of a hermetic compressor which illustrates a second embodiment according to the present invention. Fig. 4 is a plan view. An internal structure of the hermetically sealed casing 2 in a hermetic compressor 31 is the same as that of the hermetic compressor 1 according to the first embodiment. Accordingly, the same reference numerals will be given to respective portions, and description thereof will be omitted.
Similar to the hermetically sealed casing 2, an external tank 32 jointly installed outside the hermetically sealed casing 2 is a cylindrical tank disposed so that the axial direction is vertically oriented. For example, the external tank 32 has an outer diameter smaller than that of the hermetically sealed casing 2. The external tank 32 is formed to include an upper shell plate 32a, a lower shell plate 32b, an upper end plate 32c fixed to the upper end portion of the upper shell plate 32a, an intermediate end plate 32d fixed to the upper end portion of the lower shell plate 32b, and a lower end plate 32e fixed to the lower end portion of the lower shell plate 32b. The lower end portion of the upper shell plate 32a is fixed by being fitted into the periphery of the intermediate end plate 32d.
As illustrated in Figs. 3 and 4, the outer peripheral surface of the external tank 32 (upper shell plate 32a) is attached to a tank attachment bracket 34 fixed to an outer surface intermediate portion of the hermetically sealed casing 2 by means of welding. The external tank 32 is held by a metal band 35 whose both ends are locked by the tank attachment bracket 34, and is fixed so as to be combined with the hermetically sealed casing 2.
The accumulator chamber 36 and the oil storage chamber 37 are formed as each separate chamber inside the external tank 32. Specifically, an upper space inside the external tank 32, that is, a space between the upper end plate 32c and the intermediate end plate 32d serves as the accumulator chamber 36, and a space between the intermediate end plate 32d and the lower end plate 32e serves as the oil storage chamber 37. A vertical relationship between the accumulator chamber 36 and the oil storage chamber 37 may be reversed.
The refrigerant supply pipe 20 is provided which penetrates the top portion of the external tank 32 and communicates with the inside of the accumulator chamber 36. The baffle plate 21 having the notch 21a is disposed inside the accumulator chamber 36. In addition, the vaporized refrigerant suction pipe 22 disposed along the central axis of the external tank 32 penetrates the intermediate end plate 32d and the lower end plate 32e, and the lower end portion thereof is connected to the refrigerant suction pipe 9 of the hermetic compressor 31 via the external connection pipe 23. The upper end portion of the vaporized refrigerant suction pipe 22 is open downward from the baffle plate 21 at a predetermined interval inside the accumulator chamber 36.
The other end of the pressure equalizing pipe 25 connected to the upper portion of the oil storage chamber 37 is connected to the intermediate portion of the hermetically sealed casing 2. The bottom portion of the oil storage chamber 37 and the bottom portion of the hermetically sealed casing 2 are connected to each other by the oil supply pipe 26. Furthermore, the oil recirculating pipe 27 is connected to the upper portion of the oil storage chamber 37. Each function of the above-described respective members 20, 21, 22, 23, 25, 26, and 27 is the same as that of the members having the same reference numerals in the first embodiment.
The hermetic compressor 31 is configured as described above. As in the hermetic compressor 31, the accumulator chamber 36 and the oil storage chamber 37 are disposed inside the external tank 32 so as to be juxtaposed with each other in the axial direction. In this manner, the outer diameter of the external tank 32 can be further reduced than that of the external tank 11 according to the first embodiment. Therefore, the hermetic compressor 31 can have the more compact structure.
As described above, according to the hermetic compressors 1 and 31 in the above-described first and second embodiments, in the hermetic compressor in which the accumulator and the oil tank are jointly installed, the manufacturing cost can be reduced, and the compact structure can be achieved.
The present invention is not limited only to the configurations according to the first and second embodiments, and can be appropriately and additionally modified or improved. The embodiments having the additional modifications and improvements in this way are also included in the scope of the present invention. For example, in the above-described embodiments, a case has been described where the hermetic compressors 1 and 31 adopt a vertically installed type. However, a horizontally installed type can also be adopted.

Reference Signs List

1, 31: hermetic compressor
2: hermetically sealed casing
3: rotary compression mechanism (compression mechanism unit)
4: scroll compression mechanism (compression mechanism unit)
5: electric motor
11, 32: external tank
16, 36: accumulator chamber
17, 37: oil storage chamber
O: refrigerant oil
R: liquid refrigerant

Claims

A hermetic compressor comprising:
a hermetically sealed casing;

a compression mechanism unit and an electric motor for driving the compression mechanism unit which are accommodated inside the hermetically sealed casing; and

an external tank jointly installed outside the hermetically sealed casing,

wherein an accumulator chamber and an oil storage chamber are formed as each separate chamber inside the external tank.
The hermetic compressor according to Claim 1,
wherein inside the external tank, the accumulator chamber is disposed on an inner peripheral side, and the oil storage chamber is disposed on an outer peripheral side.
The hermetic compressor according to Claim 2,
wherein the external tank is disposed so that an axial direction thereof is vertically oriented, and a bottom portion of the accumulator chamber is separated upward from a bottom portion of the oil storage chamber.
The hermetic compressor according to Claim 1,
wherein inside the external tank, the accumulator chamber and the oil storage chamber are disposed so as to be juxtaposed with each other in an axial direction.