JP2000054975A - Two-stage compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate inside leak, and improve efficiency by decreasing a suction overheat amount. SOLUTION: A low-stage-side compressing mechanism 5L and a high-stage-side compressing mechanism 5H are accommodated in a casing 31. Inside of the casing 31 is divided by a partition member 3M as a first sealing chamber 3A and a second sealing chamber 3B. The first sealing chamber 3A accommodates a motor 40 and is constituted under low pressure atmosphere by being connected to suction pipe 2r of low-pressure refrigerant. The second sealing chamber 3B accommodates the low- stage-side compressing mechanism 5L and the high-stage-side compressing mechanism 5H which are connected to the motor 40, and is constituted under medium pressure atmosphere by communicating with an injection pipe 2B of medium-pressure refrigerant. A suction passage 51 of the low-stage-side compressing mechanism 5L communicates with the first sealing chamber 3A, and a delivery passage 53 of the low-stage-side compressing mechanism 5L opens the second sealing chamber 3B. A suction passage 52 of the high-stage-side compressing mechanism 5H communicates with the second sealing chamber 3B, and a delivery passage 54 of the high-stage-side compressing mechanism 5H communicates with a delivery pipe 2d of high-pressure refrigerant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-stage compressor, and more particularly to a measure for improving compressor efficiency.

[0002]

2. Description of the Related Art Conventionally, a two-stage compressor has been disclosed in
As disclosed in JP-A-133366, there is a configuration in which a low-stage compression mechanism and a high-stage compression mechanism are provided in a casing.

[0003] In the low-stage compression mechanism, a suction-side refrigerant pipe of a refrigerant circuit is connected to a suction port to supply low-pressure refrigerant. On the other hand, the discharge port of the low-stage compression mechanism is connected to the suction port of the high-stage compression mechanism via an intermediate passage, and the intermediate passage is supplied with intermediate-pressure refrigerant from gas-liquid separation provided in the refrigerant circuit. Is done. The discharge port of the high-stage compression mechanism is opened in a casing, and the casing is connected to a suction-side refrigerant pipe of a refrigerant circuit.

[0004] The low-stage compression mechanism sucks the low-pressure refrigerant in the refrigerant circuit and compresses the refrigerant into an intermediate-pressure refrigerant. Thereafter, the intermediate-pressure refrigerant is sucked into the high-stage compression mechanism together with the intermediate-pressure refrigerant supplied from the gas-liquid separator, and the high-stage compression mechanism compresses the intermediate-pressure refrigerant into a high-pressure refrigerant and discharges it.

[0005] In this two-stage compressor, since the intermediate-pressure refrigerant is used, the refrigerating capacity is improved by the economizer effect.

[0006]

However, in the two-stage compressor described above, there is a problem that the internal leakage is large because the inside of the casing is formed in a high-pressure atmosphere. In other words, the low-stage compression mechanism has a problem that a differential pressure between the low pressure of the compression chamber and the high pressure that is the discharge pressure occurs, causing internal leakage and low efficiency.

Further, since the temperature of the lubricating oil becomes equal to the temperature of the high-pressure refrigerant, the amount of superheat of the suction increases, and there is a problem that the efficiency of the compressor is low.

The present invention has been made in view of the above points, and has as its object to eliminate internal leakage and reduce the amount of overheating of suction to improve efficiency.

[0009]

SUMMARY OF THE INVENTION In the present invention, the inside of a casing is divided into a first closed chamber and a second closed chamber by a partition member, and the second closed chamber is configured to have an intermediate pressure atmosphere. It is like that.

-Solution Means- Specifically, as shown in FIG. 1, a first solution means is to firstly provide a casing (31) with a low-stage compression mechanism (5L) and a high-stage compression mechanism (5H). Are stored, and both compression mechanisms (5L, 5H)
Discharges high-pressure fluid by compressing low-pressure fluid in two stages
It assumes a stage compressor. A partition member (3M) is provided in the casing (31), and the inside of the casing (31) is partitioned into a first closed chamber (3A) and a second closed chamber (3B). In (3A), a motor (40) is housed, and a low-pressure fluid suction pipe (2r) is connected to form a low-pressure atmosphere. Furthermore, the second closed chamber (3
B) The drive shaft (32) of the motor (40) is a partition member (3M)
And is connected to the drive shaft (32) to accommodate the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H). An introduction pipe (2B) for introducing the intermediate pressure fluid communicates with the medium to form an intermediate pressure atmosphere. In addition, the suction port (51) of the low-stage compression mechanism (5L) communicates with the first closed chamber (3A), and the discharge port (53) of the low-stage compression mechanism (5L) is connected to the second closed chamber. (3B), while the suction port (52) of the high-stage compression mechanism (5H) is
The discharge port (54) of the high-stage compression mechanism (5H) communicates with the closed chamber (3B), and the discharge pipe (2d) for high-pressure fluid.

In a second solution, as shown in FIG. 7, first, a low-stage compression mechanism (5L) is attached to a casing (31).
And a high-stage compression mechanism (5H). The two-stage compressor presumes that the two-stage compression mechanism (5L, 5H) compresses the low-pressure fluid in two stages and discharges the high-pressure fluid. A partition member (6m) is provided in the casing (31), and the casing (31) has a first closed chamber (3A) and a second closed chamber (3B).
The first closed chamber (3A) houses a high-stage compression mechanism (5H) and is connected to a discharge pipe (2d) to form a high-pressure atmosphere. Further, the second closed chamber (3B) accommodates the low-stage compression mechanism (5L),
An introduction pipe (2B) for introducing an intermediate-pressure fluid intermediate between the low-pressure fluid and the high-pressure fluid communicates with each other to form an intermediate-pressure atmosphere.
In addition, the suction port (51) of the low-stage compression mechanism (5L) communicates with the suction pipe (2r) for low-pressure fluid, and the discharge port (53) of the low-stage compression mechanism (5L) is in the second sealed state. While opening to the chamber (3B), the suction port (52) of the high-stage compression mechanism (5H) passes through the partition member (6m) and passes through the intermediate passage (56) through which the introduction pipe communicates. Inlet (5L) of stage side compression mechanism (5L)
1) and discharge port (5H) of the high-stage compression mechanism (5H).
4) is open to the first closed chamber (3A).

According to a third aspect of the present invention, in the above second aspect, the partition member (6m) includes a first closed chamber (3A).
And a small-diameter passage (67) for returning the lubricating oil to the second closed chamber (3B).

According to a fourth solution, in the second solution, a motor (40) is housed in the first closed chamber (3A), and a drive shaft (32) of the motor (40) is It is connected to the high-stage compression mechanism (5H), extends through the partition member (6m) to the second closed chamber (3B), and is connected to the low-stage compression mechanism (5H).
L), a lubricating oil supply passage (34) is formed in the drive shaft (32), and the oil supply passage (34) is configured to supply the lubricating oil in a state where gas is sealed therein. It was done.

As shown in FIG. 2, the fifth solution is that the heat source side heat exchanger (22) is provided between the discharge pipe (2d) and the suction pipe (2r) in the first solution. ), The first expansion mechanism (E1), the gas-liquid separator (23), the second expansion mechanism (E2), and the use-side heat exchanger (24) are connected in order to form a refrigerant circuit (20) through which the refrigerant circulates. It has a connected configuration. And
The gas-liquid separator (23) is connected to the introduction pipe (2B) so as to supply the intermediate-pressure refrigerant, while the refrigerant circuit (20)
The low-pressure refrigerant evaporated in one heat exchanger (24) is supplied to the suction pipe (2r) as it is.

As shown in FIG. 8, the sixth solution of the second solution is that the heat source side heat exchanger (22) is provided between the discharge pipe (2d) and the suction pipe (2r). ), The first expansion mechanism (E1), the gas-liquid separator (23), the second expansion mechanism (E2), and the use-side heat exchanger (24) are connected in order to form a refrigerant circuit (20) through which the refrigerant circulates. It has a connected configuration. And
An inlet pipe (2B) is connected to the gas-liquid separator (23) so as to supply an intermediate-pressure refrigerant, while an accumulator (25) is provided on a side of the suction pipe (2r) in the refrigerant circuit (20). Is provided.

-Operation- According to the above-mentioned specific matter, in the first solution, first, when the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H) are driven, the low-pressure fluid is supplied to the first closed chamber (5). 3A), flows into the cylinder chamber (6s) from the suction passage (51) of the low-stage compression mechanism (5L), and in particular, in the fifth solution, the low-pressure pressure without being separated from the refrigerant circuit (20) Refrigerant flows in.

On the other hand, since the intermediate-pressure refrigerant is supplied to the second sealed chamber (3B) from the gas-liquid separator (23), the intermediate-pressure refrigerant discharged from the low-stage compression mechanism (5L) and the gas-liquid Separator (2
The intermediate-pressure refrigerant supplied from 3) joins in the second closed chamber (3B), and is joined to the cylinder chamber (6) of the high-stage compression mechanism (5H).
s).

In the high-stage compression mechanism (5H), the intermediate-pressure refrigerant is compressed and the high-pressure refrigerant is discharged to the refrigerant circuit (20), and the refrigerant circulates in the refrigerant circuit (20).

In the second solution, when the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H) are driven, the low-pressure fluid is supplied to the suction port (51) of the low-stage compression mechanism (5L). In particular, in the sixth solution, the low-pressure refrigerant flows from the refrigerant circuit (20) through the accumulator (25).

On the other hand, since the intermediate-pressure refrigerant is supplied to the second closed chamber (3B) from the gas-liquid separator (23), the intermediate-pressure refrigerant discharged from the low-stage compression mechanism (5L) and the gas-liquid Separator (2
The intermediate-pressure refrigerant supplied from 3) joins in the second closed chamber (3B), and is joined to the cylinder chamber (6) of the high-stage compression mechanism (5H).
s).

In the high-stage compression mechanism (5H), the intermediate-pressure refrigerant is compressed and the high-pressure refrigerant is discharged into the first closed chamber (3A). The high-pressure refrigerant is discharged to the refrigerant circuit (20), and the refrigerant circulates through the refrigerant circuit (20).

According to a third aspect of the present invention, in the second aspect, the lubricating oil discharged into the first closed chamber (3A) passes through a small-diameter passageway (67) to a bottom portion of the casing (31). Return to

According to a fourth solution, in the second solution, the lubricating oil is supplied to the oil supply passage (34) of the drive shaft (32) while the gas is sealed.

[0024]

Thus, according to the present invention, the intermediate-pressure refrigerant is supplied to the intermediate passage (56) between the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H). Since the capacity and the heating capacity can be improved, the COP (coefficient of performance) can be improved.

Further, since the refrigerant is compressed in two stages, an increase in the discharge temperature of the refrigerant can be suppressed.

Further, since the second closed chamber (3B) is configured to have an intermediate pressure atmosphere, the surroundings of the compression chamber and the like are at an intermediate pressure atmosphere, and the low stage side compression mechanism (5L) has a low pressure and an intermediate pressure. In the high-stage compression mechanism (5H), there is a pressure difference between the high pressure and the intermediate pressure. As a result, since internal leakage can be suppressed, efficiency can be improved.

Further, since the temperature of the lubricating oil can be set to the temperature of the intermediate-pressure refrigerant, the amount of suction overheating can be reduced, and the efficiency of the compressor can be improved.

According to the third solution, the lubricating oil returns to the bottom of the casing (31) through the small-diameter passage (67), so that the oil can be surely prevented from running out.

Further, according to the fourth solution, since no vent hole is formed in the oil supply passage (34), the backflow of the fluid can be reliably prevented.

According to the fifth solution, the motor (40) is housed in the first closed chamber (3A), and the low-pressure refrigerant that does not separate gas and liquid flows from the refrigerant circuit (20). Since the motor (40) can be reliably cooled, the motor efficiency can be improved.

[0031]

Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 2, the air conditioner (10)
Is a heat pump type air conditioner, which is configured to be switchable between a cooling operation and a heating operation.

The refrigerant circuit (20) of the air conditioner (10)
Are a compressor (30), a four-way switching valve (21), an outdoor heat exchanger (22) as a heat source side heat exchanger, a first expansion valve (E1) as a first expansion mechanism, and a gas-liquid separator ( 23) a main refrigerant circuit (2M) in which a second expansion valve (E2) as a second expansion mechanism and an indoor heat exchanger (24) as a use side heat exchanger are connected in order by a refrigerant pipe (26). It has. In particular, an accumulator is omitted between the four-way switching valve (21) and the suction side of the compressor (30).

The four-way switching valve (21) switches between a cooling operation indicated by a solid line in FIG. 2 and a heating operation indicated by a broken line in FIG.

The refrigerant circuit (20) is provided with an injection pipe (2B). The injection pipe (2B) is an introduction pipe for injecting an intermediate-pressure gas refrigerant, which is an intermediate-pressure fluid, into the compressor (30), and has one end connected to the gas-liquid separator (23) and the other end connected to the compressor (30). ). That is, the gas-liquid separator (23) stores an intermediate-pressure refrigerant having an intermediate pressure between the condensing pressure of the refrigerant as the high-pressure fluid and the evaporation pressure of the refrigerant as the low-pressure fluid. The injection pipe (2B) passes the gas-phase intermediate-pressure gas refrigerant of the intermediate-pressure refrigerant of the gas-liquid separator (23) to the compressor (3).
Inject to 0).

The first expansion valve (E1) and the second expansion valve (E2)
Is composed of a motor-operated valve whose opening can be adjusted freely. And
The intermediate-pressure refrigerant depressurized by the first expansion valve (E1) or the second expansion valve (E2) is stored in the gas-liquid separator (23).

The compressor (30) is configured to control the operating capacity steplessly or in multiple steps. As a feature of the present invention, as shown in FIG.
As shown in FIG. 1, a motor (40) and a low-stage compression mechanism (5L) and a high-stage compression mechanism (5H) are housed in a closed casing (31). It is configured.

The casing (31) is provided with a partition member (3M) substantially at the center in the vertical direction, and the partition member (3M) is provided in close contact with the inner peripheral surface of the casing (31). Have been. The first part above the partition member (3M) is the first part.
A closed chamber (3A) is provided, and a motor (40) is housed in the first closed chamber (3A). The lower part of the partition member (3M) is a second closed chamber (3B), and the second closed chamber (3B) houses a low-stage compression mechanism and a high-stage compression mechanism.

The upper part of the casing (31) is connected to the suction side refrigerant pipe (2r) of the main refrigerant circuit (2M), and the first closed chamber (3A) is constructed in a low pressure atmosphere. The suction-side refrigerant pipe (2r) is configured as a suction pipe for supplying a low-pressure gas refrigerant.

On the other hand, an injection pipe (2B) is connected to the center of the casing (31), and the injection pipe (2B) communicates with the second closed chamber (3B).
That is, the second closed chamber (3B) is supplied with the intermediate-pressure gas refrigerant and is configured to have an intermediate-pressure atmosphere.

The motor (40) includes a stator (41) fixed to an inner peripheral surface of a casing (31), and a stator (41).
And a rotor (42) arranged at the center of the. The drive shaft (32) is connected to the center of the rotor (42). The drive shaft (32) extends downward through the partition member (3M), and is connected to the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H).

The bottom of the casing (31) is formed as an oil reservoir (33) for lubricating oil. The lower end of the drive shaft (32) is immersed in the lubricating oil of the oil reservoir (33). ing.
Although not shown, a centrifugal oil pump (not shown) is provided at the lower end of the drive shaft (32), and lubricating oil passes through an oil supply passage (34) in the drive shaft (32) and is compressed at a lower stage. It is supplied to the sliding parts of the mechanism (5L) and the high-stage compression mechanism (5H).

The low-stage compression mechanism (5L) and the high-stage compression mechanism (5H) are located vertically below the motor (40). Each of the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H) is a so-called swing type rotary compressor as a feature of the present invention.

The low-stage compression mechanism (5L) and the high-stage compression mechanism (5H) have substantially the same configuration, and the high-stage compression mechanism (5H) is located below the low-stage compression mechanism (5L). Is arranged. As shown in FIG. 3, the compression mechanisms (5L, 5H) each include a piston (61) housed in a cylinder chamber (6s) formed in a cylinder (60). A middle plate (6m) is provided between the cylinders (60) of the two compression mechanisms (5L, 5H), and an upper plate (6u) is provided on the upper surface of the low-stage cylinder (60) and closed. The lower surface of the high-stage side cylinder (60) is provided with a lower plate (6d) and closed.

On the other hand, the piston (61) of each compression mechanism (5L, 5H) is formed in an annular shape, and the eccentric shaft (62) is rotatably fitted therein. The eccentric shaft (62) is formed eccentric to the drive shaft (32).

Each cylinder (60) has a suction passage (51,
52) is formed, and one end of the suction passage (51, 52) opens to the cylinder chamber (6s) to form a suction port. A discharge passage (53) for the low-stage compression mechanism (5L) is formed in the upper plate (6u), while a discharge passage (54) for the high-stage compression mechanism (5H) is formed in the lower plate (6d). ) Is formed, and one end of each of the discharge passages (53, 54) opens to the cylinder chamber (6s) to form a discharge port. Although not shown, each of the discharge passages (53, 54) is provided with a discharge valve that opens a discharge port when a predetermined discharge pressure is reached.

In the cylinder (60), a cylindrical bush hole (63) is formed between the suction port and the discharge port so as to open in the cylinder chamber (6s). The piston (61) has a blade (6
4) is integrally formed. The tip side of the blade (64) has a pair of swinging bushes (6
b) has been inserted through.

The blade (64) is provided in the cylinder chamber (6s).
To the low-pressure chamber and the discharge passage (5
It is divided into a high-pressure chamber that leads to (3, 54). The piston (61) is connected to the swinging bush (6) through the blade (64).
It is configured to swing around the fulcrum b) and revolve around the cylinder chamber (6s) to compress the refrigerant.

The suction passage (5) of the low-stage compression mechanism (5L)
1) communicates with the low pressure passage (55) passing through the upper plate (6u) and the partition member (3M), and the low-stage compression mechanism (5L)
Is configured to supply a low-pressure gas refrigerant.
Also, the discharge passage (53) of the low-stage compression mechanism (5L)
The upper plate (5u) communicates with the second closed chamber (3B).

The upper plate (6u), the low-stage cylinder (60), and the middle plate (6m) are formed with an intermediate passage (56) penetrating vertically. The intermediate passage (56)
The upper end communicates with the second closed chamber (3B), the lower end communicates with the suction passage (52) of the high-stage compression mechanism (5H), and the intermediate-pressure refrigerant is supplied to the high-stage compression mechanism (5H). You.

The lower plate (6d) is provided with a lower muffler (65), and the lower muffler (65) communicates with the discharge passage (54) of the high-stage compression mechanism (5H). . The lower plate (6d), the high-stage cylinder (60), and the middle plate (6m) pass through the high-pressure passage (5
7) is formed. The high pressure passage (57) has a lower end communicating with the lower muffler (65), and an upper end connected to the discharge side refrigerant pipe (2d) of the main refrigerant circuit (2M). The discharge-side refrigerant pipe (2d) is configured as a discharge pipe that discharges a high-pressure gas refrigerant.

As shown in FIG. 4, a sealing means (70) is provided at a portion of the drive shaft (32) penetrating the partition member (3M). The sealing means (70) includes a flange (71) formed on the drive shaft (32) and a boss (72) formed on the upper plate (6u). A large-diameter recess (73) is formed at the lower end of the shaft hole of the partition member (3M), and the flange (71) of the drive shaft (32) is located in the large-diameter recess (73). ing.

The inner peripheral portion of the upper surface of the boss portion (6n) is formed on a sealing surface (74) in contact with the lower surface of the flange portion (71) of the drive shaft (32). Three
The space between A) and the second closed chamber (3B) of the intermediate pressure atmosphere is sealed.

Further, the boss (6n) and the flange (7
1) is also used as the thrust bearing of the drive shaft (32). That is, the flange (71) is pressed against the boss (6n) by the magnetic pull force of the motor (40) in addition to the weight of the drive shaft (32) and the pistons (61, 61).

The lower surface of the partition member (3M) at the periphery of the large-diameter concave portion (73) is in close contact with the upper surface of the boss (72) of the upper plate (6u). The partition member (3M) is provided with an O-ring (75) to seal between the second closed chamber (3B) and the large-diameter concave portion (73).

A spiral pump (7P) is provided between the drive shaft (32) and the shaft hole of the upper plate (6u). The spiral pump (7P)
Supplies the lubricating oil supplied to the shaft hole of the upper plate (6u) to the seal surface (74). Then, the lubricating oil lubricates the sealing surface (74).

-Air Conditioning Operation- Next, the air conditioning operation of the air conditioner (10) will be described.

First, during the indoor cooling operation, the four-way switching valve (21) is switched to the solid line side in FIG. The refrigerant discharged from the compressor (30) exchanges heat with outside air in the outdoor heat exchanger (22) and condenses. This liquid refrigerant is reduced in pressure by the first expansion valve (E1), becomes an intermediate-pressure refrigerant having an intermediate pressure between the condensing pressure and the evaporation pressure, and accumulates in the gas-liquid separator (23).

Among the intermediate-pressure refrigerant in the gas-liquid separator (23), the intermediate-pressure liquid refrigerant is decompressed by the second expansion valve (E2), and then exchanges heat with indoor air in the indoor heat exchanger (24). To evaporate and cool the room air. Thereafter, the gas refrigerant returns directly to the compressor (30), and performs the refrigerant circulation operation.

On the other hand, during the heating operation, the four-way switching valve (21)
Is switched to the broken line side in FIG. The refrigerant discharged from the compressor (30) exchanges heat with the indoor air in the indoor heat exchanger (24) and condenses while heating the indoor air. Thereafter, the liquid refrigerant is reduced in pressure by the second expansion valve (E2), becomes an intermediate-pressure refrigerant, and accumulates in the gas-liquid separator (23).

Among the intermediate-pressure refrigerants in the gas-liquid separator (23), the intermediate-pressure liquid refrigerant is depressurized by the first expansion valve (E1), and then exchanges heat with the outside air in the outdoor heat exchanger (22). And evaporate. Thereafter, the gas refrigerant returns directly to the compressor (30), and performs the refrigerant circulation operation.

At the time of the air conditioning operation described above, since the injection pipe (2B) is provided, the gas-liquid separator (2B) is provided.
The intermediate-pressure gas refrigerant of 3) is injected into the compressor (30).

The change in the characteristics of the refrigerant in the refrigerant circuit (20) will be described in detail with reference to FIG.

First, the refrigerant in the compressor (30) is
It is compressed from the low pressure state at the point E to the high pressure state of the condensation pressure at the point F. This high-pressure gas refrigerant is condensed in the outdoor heat exchanger (22) or the indoor heat exchanger (24) and becomes a high-pressure liquid refrigerant at point G.
The high-pressure liquid refrigerant is reduced to an intermediate-pressure refrigerant at point H by the first expansion valve (E1) or the second expansion valve (E2), stored in the gas-liquid separator (23), and stored in the gas-liquid separator (23). ) To separate into intermediate-pressure liquid refrigerant and intermediate-pressure gas refrigerant.

The separated intermediate-pressure gas refrigerant is injected into the compressor (30) (see the point I) via the injection pipe (2B), while the intermediate-pressure liquid refrigerant is supplied from the point J to the second expansion valve ( E2) or the first expansion valve (E1) reduces the pressure to the low-pressure two-phase refrigerant to point K. The low-pressure two-phase refrigerant evaporates in the indoor heat exchanger (24) or the outdoor heat exchanger (22), changes to point E, and returns to the compressor (30).

As a result, during the heating operation, the refrigerant flowing through the indoor heat exchanger (24) serving as the condenser is added with the intermediate-pressure gas refrigerant, so that the refrigerant circulation amount increases, and the heating capacity is improved. .

On the other hand, during the cooling operation, the enthalpy of the low-pressure two-phase refrigerant at the point K from the point H to the point J increases, so that the amount of heat of the refrigerant evaporated in the indoor heat exchanger (24) increases. The cooling capacity is improved.

Further, as shown in FIG. 6, the power of the X portion is reduced.

Next, the compression operation of the compressor (30) will be described.

The driving shaft (32) is driven by driving the motor (40).
Rotates, and the pistons (61) of the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H) swing around the center of the bush hole (63) as a fulcrum to revolve. And the main refrigerant circuit (2M)
The low-pressure gas refrigerant returned from flows into the first closed chamber (3A). In particular, since the main refrigerant circuit (2M) is not provided with an accumulator, the low-pressure refrigerant evaporated in the indoor heat exchanger (24) or the outdoor heat exchanger (22) is directly transferred to the first closed chamber (3).
A).

Thereafter, the low-pressure refrigerant passes between the stator (41) and the rotor (42) of the motor (40), the low-pressure liquid refrigerant evaporates, and passes through the low-pressure passage (55) to the low-stage compression mechanism ( Five
L) from the suction passage (51) into the cylinder chamber (6s),
It is compressed by the swing of the piston (61).

On the other hand, since the intermediate-pressure refrigerant is supplied from the gas-liquid separator (23) to the second closed chamber (3B), the discharge valve of the low-stage compression mechanism (5L) is connected to the cylinder chamber (6s). It opens when the refrigerant pressure in () becomes an intermediate pressure. Thereafter, the intermediate-pressure refrigerant discharged from the low-stage compression mechanism (5L) and the intermediate-pressure refrigerant supplied from the gas-liquid separator (23) merge in the second closed chamber (3B), and pass through the intermediate passage (56). Flows into the cylinder chamber (6s) of the high-stage compression mechanism (5H).

The high-stage compression mechanism (5H) compresses the intermediate-pressure refrigerant and discharges the high-pressure refrigerant to the lower muffler (65). This high-pressure refrigerant passes through the high-pressure passage (57) and is discharged to the main refrigerant circuit (2M). This high-pressure refrigerant circulates through the refrigerant circuit (20) as described above.

According to the present embodiment, the intermediate-pressure refrigerant is supplied to the intermediate passage (56) between the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H). As a result, the cooling capacity and the heating capacity can be improved, so that the COP (coefficient of performance) can be improved.
Can be improved.

Further, since the refrigerant is compressed in two stages, an increase in the discharge temperature of the refrigerant can be suppressed.

Further, since the motor (40) is housed in the first closed chamber (3A) and the low-pressure refrigerant that does not separate gas and liquid flows therein, the motor (40) can be cooled reliably. Thus, the motor efficiency can be improved.

Further, since the second closed chamber (3B) is configured to have an intermediate pressure atmosphere, the periphery of the eccentric shaft (62) and the like are in an intermediate pressure atmosphere, and the low stage side compression mechanism (5L) has a low pressure. It becomes the pressure difference between the intermediate pressure and the pressure difference between the high pressure and the intermediate pressure in the high-stage compression mechanism (5H). As a result, since internal leakage can be suppressed, efficiency can be improved.

Further, since the temperature of the lubricating oil can be set to the temperature of the intermediate-pressure refrigerant, the amount of suction overheating can be reduced, and the efficiency of the compressor can be improved.

Further, since the rotary compressor in which the piston (61) and the blade (64) are integrated is applied, the blade (64) and the piston (61) are compared with the rolling piston type rotary compressor. Does not come into contact with Therefore, wear of the blade (64) can be suppressed.

In particular, in the high-stage compression mechanism (5H),
Although the temperature of the discharged refrigerant increases, there is no wear of the blade (64), so that the influence of friction can be more reliably suppressed.

As a result, foreign matter due to the abrasion does not flow through the refrigerant circuit (20), and blockage of the circuit can be reliably prevented.

[0082]

Embodiment 2 In this embodiment, as shown in FIG. 7, a lower stage compression mechanism (5L) is placed under a lower stage compression mechanism (5L).
H) is arranged upward, while the partition member (3
The middle plate (6m) is a partition member (3M), omitting M)
Is also used.

The middle plate (6m) is provided such that its outer peripheral surface is in close contact with the inner peripheral surface of the casing (31), and the inside of the casing (31) is the first plate above the middle plate (6m).
The lower part of the middle plate (6 m) is partitioned into a second closed chamber (3B) in the closed chamber (3A). The first closed chamber (3A) houses the motor (40) and the high-stage compression mechanism (5H), and the second closed chamber (3B) houses the low-stage compression mechanism (5L). I have.

The lower stage compression mechanism (5L) is formed between the lower plate (6d) and the middle plate (6m), and the higher stage compression mechanism (5H) is formed between the middle plate (6m) and the upper plate (6u). Is formed between. The lower plate (6d) has a discharge passage (53) for the low-stage compression mechanism (5L).
And a lower muffler (65) is provided.

The lower plate (6d), the lower cylinder (60), the middle plate (6m), and the higher cylinder (60)
An intermediate passage (56) is formed vertically. The intermediate passage (56) communicates with the lower muffler (65) and the suction passage (52) of the high-stage compression mechanism (5H).

An injection pipe (2B) is connected to the middle plate (6m), and the injection pipe (2B) communicates with the intermediate passage (56) and communicates with the second closed chamber (3B). 58), the second closed chamber (3B) is configured to have an intermediate pressure atmosphere.

On the other hand, a discharge passage (54) for the high-stage compression mechanism (5H) is formed in the upper plate (6u), and an upper muffler (66) for covering the discharge passage (54) is provided. ing. The high-pressure refrigerant is supplied to the upper muffler (66)
Is discharged to the first closed chamber (3A) through the second closed chamber (3A).
B) is configured in a high-pressure atmosphere.

Then, a discharge side refrigerant pipe (2d) communicating with the first closed chamber (3A) is provided above the casing (31).
The suction side refrigerant pipe (2r) is connected to the cylinder (60) of the low-stage compression mechanism (5L) so as to communicate with the suction passage (51).

The middle plate (6m) is provided with a small-diameter passage (67) for returning lubricating oil from the first closed chamber (3A) to the second closed chamber (3B). That is, since the lubricating oil discharged from the high-stage compression mechanism (5H) accumulates above the middle plate (6m), the small-diameter passage (67) stores the lubricating oil in the lower oil reservoir in the casing (31). Return to section (33).

The oil supply path (34) of the drive shaft (32) is
No gas vent hole is formed, and the lubricating oil is supplied to the sliding parts of the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H) while the gas refrigerant is sealed. I have.

As shown in FIG. 8, the refrigerant circuit (20)
Is provided with an accumulator (25) between the four-way switching valve (21) and the compressor (30), and the accumulator (25)
Only the low-pressure gas refrigerant that has been gas-liquid separated is configured to return to the compressor (30). Other configurations are the same as those of the first embodiment.

Therefore, the low-pressure gas refrigerant separated into gas and liquid by the accumulator (25) flows directly from the refrigerant circuit (20) into the low-stage compression mechanism (5L). And
The intermediate-pressure refrigerant compressed by the low-stage compression mechanism (5L) is discharged from the discharge passage (53) to the lower muffler (65), passes through the intermediate passage (56), and is sucked into the high-stage compression mechanism (5H). (52), and the injection pipe (2B) in this intermediate passage (56)
Of the intermediate-pressure refrigerants merge. The high-pressure refrigerant discharged from the high-stage compression mechanism (5H) flows from the upper muffler (66) to the first closed chamber (3H).
A) is discharged. Thereafter, the high-pressure refrigerant is supplied to the motor (4
0), flows between the stator (41) and the rotor (42), flows out to the refrigerant circuit (20), and circulates through the refrigerant circuit (20).
Other operations are the same as those of the first embodiment.

According to the present embodiment, in addition to the effect of the first embodiment, the lubricating oil returns to the bottom of the casing (31) via the small-diameter passage (67), so that the oil can be surely prevented from running out. .

Further, since no gas vent hole is formed in the oil supply passage (34), backflow of the fluid can be reliably prevented. Other effects are the same as those of the first embodiment.

[0095]

Third Embodiment As shown in FIG. 9, this embodiment shows a modification of the sealing means (70) in the first embodiment. In the sealing means (70), a plurality of annular grooves (7a) are formed in a portion of the drive shaft (32) penetrating the partition member (3M) to form a labyrinth seal. The sealing means (70) seals the space between the first closed chamber (3A) in a low-pressure atmosphere and the second closed chamber (3B) in an intermediate-pressure atmosphere.

Although not shown, a thrust bearing is provided between the drive shaft (32) and the lower plate (6d). Other configurations, operations and effects are the same as those of the first embodiment.

[0097]

Fourth Embodiment In this embodiment, as shown in FIG. 10, instead of the annular groove (7a) of the sealing means (70) in the third embodiment, an annular groove (7b) is formed in the partition member (3M). Is provided. That is, the sealing means (70) forms a labyrinth seal by forming a plurality of annular grooves (7b) on the inner peripheral surface of the shaft hole of the partition member (3M) through which the drive shaft (32) passes. The sealing means (70) seals the space between the first closed chamber (3A) in a low-pressure atmosphere and the second closed chamber (3B) in an intermediate-pressure atmosphere. Other configurations, operations and effects are the same as those of the third embodiment.

[0098]

Embodiment 5 In this embodiment, as shown in FIG. 11, a sliding seal (7d) is provided instead of the annular groove (7a) of the sealing means (70) in Embodiment 3. is there.

That is, the sealing means (70) has a plurality of annular grooves (7 c) formed in the drive shaft (32) through the partition member (3 M) and slides into each of the annular grooves (7 c). A dynamic seal (7d) is provided. The sealing means (70) seals the space between the first closed chamber (3A) in a low-pressure atmosphere and the second closed chamber (3B) in an intermediate-pressure atmosphere. Other configurations, operations and effects are the same as those of the third embodiment.

[0100]

Another embodiment of the present invention is a so-called low-stage compression mechanism (5L) and high-stage compression mechanism (5H) in which a piston (61) and a blade (64) are integrally formed. Although the swing type rotary compressor is applied, the present invention may apply a rolling piston type rotary compressor in which the piston (61) and the blade (64) are separated.

The low-stage compression mechanism (5L) and the high-stage compression mechanism (5H) may be constituted by scroll compressors. In other words, the low-stage compression mechanism (5L) and the high-stage compression mechanism (5H) are not shown in the drawing, but the fixed scroll and the movable scroll, each of which has a spiral wrap protrudingly formed on one side of the end plate, engage with each other. The orbiting scroll is arranged so as to revolve only to compress the fluid.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a compressor according to a first embodiment.

FIG. 2 is a refrigerant circuit diagram showing the first embodiment.

FIG. 3 is a plan sectional view showing a low-stage compression mechanism and a high-stage compression mechanism.

FIG. 4 is a longitudinal sectional view showing a sealing means.

FIG. 5 is a Mollier chart showing refrigerant characteristics of the refrigerant circuit of the first embodiment.

FIG. 6 is a state diagram showing a relationship between pressure and volume of the compressor of the first embodiment.

FIG. 7 is a longitudinal sectional view showing a compressor according to a second embodiment.

FIG. 8 is a refrigerant circuit diagram showing Embodiment 2.

FIG. 9 is a longitudinal sectional view of a main part showing a sealing unit of a third embodiment.

FIG. 10 is a longitudinal sectional view of a main part showing a sealing means of a fourth embodiment.

FIG. 11 is a longitudinal sectional view of a main part showing a sealing means of a fifth embodiment.

[Explanation of symbols]

 10 Air conditioner 20 Refrigerant circuit 2B Injection pipe (introduction pipe) 30 Compressor 31 Casing 40 Motor 5L Low stage compression mechanism 5H High stage compression mechanism 51, 52 Suction passage 53, 54 Discharge passage 56 Intermediate passage 60 Cylinder 61 Piston 64 Blade 70 Sealing means

Claims (6)

[Claims] A low-stage compression mechanism (5) is provided on a casing (31).
L) and the high-stage compression mechanism (5H) are housed, and the two-stage compression mechanism (5L, 5H) compresses the low-pressure fluid in two stages and discharges the high-pressure fluid. The casing (31) is partitioned into a first closed chamber (3A) and a second closed chamber (3B), and the first closed chamber (3A) is provided with a motor (3M). 40) is housed, and a low-pressure fluid suction pipe (2r) is connected to form a low-pressure atmosphere. The second closed chamber (3B) is provided with a drive shaft (32) of a motor (40).
Is extended through the partition member (3M) and the drive shaft (32)
The low-pressure side compression mechanism (5L) and the high-pressure side compression mechanism (5H) are housed and connected to an inlet pipe (2B) for introducing an intermediate pressure fluid between the low pressure fluid and the high pressure fluid. The suction port (51) of the low-stage compression mechanism (5L) communicates with the first closed chamber (3A), and the discharge port (53) of the low-stage compression mechanism (5L). ) Opens into the second closed chamber (3B), while the suction port (52) of the high-stage compression mechanism (5H) communicates with the second closed chamber (3B), and the high-stage compression mechanism (5H) The two-stage compressor characterized in that a discharge pipe (2d) of the high-pressure fluid communicates with a discharge port (54) of the compressor. 2. A low-stage compression mechanism (5) is provided on a casing (31).
L) and the high-stage compression mechanism (5H) are housed, and the two-stage compression mechanism (5L, 5H) compresses the low-pressure fluid in two stages and discharges the high-pressure fluid. The casing (31) is partitioned into a first closed chamber (3A) and a second closed chamber (3B), and the first closed chamber (3A) is The side compression mechanism (5H) is housed, and the discharge pipe (2d) is connected to form a high-pressure atmosphere. The second closed chamber (3B) houses the low-stage compression mechanism (5L). An introduction pipe (2B) for introducing an intermediate-pressure fluid intermediate between the low-pressure fluid and the high-pressure fluid is connected to form an intermediate-pressure atmosphere. The suction port (51) of the low-stage compression mechanism (5L) is connected to the low-pressure fluid. And the discharge port (53) of the low-stage compression mechanism (5L) opens to the second closed chamber (3B), while the high-stage compression mechanism The suction port (52) of the low-stage compression mechanism (5L) passes through an intermediate passage (56) that penetrates through the partition member (6m) and communicates with the introduction pipe (2B). ), Wherein the discharge port (54) of the high-stage compression mechanism (5H) is open to the first closed chamber (3A). 3. A small-diameter passage (67) for returning lubricating oil from a first closed chamber (3A) to a second closed chamber (3B) in the partition member (6m). A two-stage compressor, comprising: 4. The two-stage compressor according to claim 2, wherein a motor (40) is housed in the first closed chamber (3A), and a drive shaft (32) of the motor (40) is a high-stage compression. While being connected to the mechanism (5H), it extends through the partition member (6m) to the second closed chamber (3B) and is connected to the low-stage compression mechanism (5L). A two-stage compressor, wherein a lubricating oil supply path (34) is formed, and the oil supply path (34) is configured to supply the lubricating oil in a state in which gas is sealed. 5. The two-stage compressor according to claim 1, wherein a heat source side heat exchanger (22), a first expansion mechanism (E1), and a gas are provided between the discharge pipe (2d) and the suction pipe (2r). Liquid separator (23) and second
The expansion mechanism (E2) and the use-side heat exchanger (24) are connected in order to connect a refrigerant circuit (20) through which the refrigerant circulates. The gas-liquid separator (23) supplies an intermediate-pressure refrigerant. While the introduction pipe (2B) is connected, the refrigerant circuit (20) is configured such that the low-pressure refrigerant evaporated in the one heat exchanger (24) is supplied to the suction pipe (2r) as it is. A two-stage compressor. 6. The two-stage compressor according to claim 2, wherein a heat source side heat exchanger (22), a first expansion mechanism (E1), and a gas are provided between the discharge pipe (2d) and the suction pipe (2r). Liquid separator (23) and second
The expansion mechanism (E2) and the use-side heat exchanger (24) are connected in order to connect a refrigerant circuit (20) through which the refrigerant circulates. The gas-liquid separator (23) supplies an intermediate-pressure refrigerant. A two-stage compressor, wherein an inlet pipe (2B) is connected, and an accumulator (25) is provided on a side of the suction pipe (2r) in the refrigerant circuit (20).