JPH06323102A - Refregerating air-conditioner and fluid machinery - Google Patents

Abstract

PURPOSE:To provide a refregerating air-conditioner which is dispensed with lubricating oil for lubrication of sliding parts of a compressor. CONSTITUTION:High temperature and high pressure coolant gas which is discharged from a compressor 100 is liquefied by a condenser 92, and reduced in its pressure by an expansion valve 93. The cooling medium liquid is then evaporated by an evaporator 94 and fed back to the compressor 100. In such a refregerating air conditioner, cooling is carried out by using evaporation heat inside the evaporator 94, while heating is carried out by using liquefying heat inside the condenser 92. A cooling medium liquid introduction circuit which has a cooling medium liquid piping 101 is provided, which circuit 101 introduces the cooling medium liquid liquefied by the condenser 92 to the sliding parts in the compressor 100. The cooling medium liquid is utilized for lubrication of the sliding parts inside the compressor 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating and air-conditioning apparatus having a fluid machine for conveying a refrigerant and a fluid machine suitable for the refrigerating and air-conditioning apparatus.

[0002]

2. Description of the Related Art FIG. 4 shows the structure of a conventional refrigeration / air-conditioning system using a refrigerant. This refrigerating and air-conditioning apparatus includes a compressor 91 as a fluid machine for conveying a refrigerant, a condenser 92, an expansion valve 93, an evaporator 94 and an accumulator 9.
It consists of 5. The high-temperature, high-pressure refrigerant gas discharged from the compressor 91 is condensed and liquefied by the condenser 92, and the expansion valve 93
After being decompressed by, the refrigerant liquid evaporates in the evaporator 94 and returns to the compressor 91.

Here, the heat generated by the evaporation in the evaporator 94 is used during cooling, and the condenser 92 is used during heating.
Refrigeration air conditioning is performed using the heat for liquefaction inside.
The accumulator 95 is for selectively returning only the refrigerant gas without returning the refrigerant liquid to the compressor 91.

FIG. 5 shows the structure of a conventional hermetic refrigeration / air-conditioning scroll compressor which is an example of a refrigerant compressor used as the compressor 91 of FIG. This figure is a vertical cross-sectional view of a scroll compressor, in which a compression element part is arranged in the upper part of the main body and an electric motor is arranged in the lower part. The compression element portion includes a fixed scroll 1, an orbiting scroll 2, and a rotation preventing member 3 that allows the orbiting of the orbiting scroll 2 and inhibits its rotation. In addition to these, a drive shaft 5 that connects the electric motor 4 and the compression element portion, a frame 6 that locks the fixed scroll 1 and the electric motor 4, upper and lower bearings 71 and 72 that support the drive shaft 5, An orbiting bearing 73 that rotatably supports the orbiting scroll 2 and a thrust bearing 74 that axially supports the orbiting scroll 2 are provided and housed in the housing 8. Lubricating oil 81 is enclosed in the lower portion of the housing 8.

The fixed scroll 1 comprises an end plate 11 and a spiral 12 formed integrally therewith. The end plate 11 has a discharge port 13, a discharge valve 17, and a discharge cavity located on the opposite side to the spiral 12. 14 are provided.

The orbiting scroll 2 comprises an end plate 21 and a spiral 22 integrally formed with the end plate 21, and a boss 23 for driving the orbiting scroll 2 is located on the opposite side of the spiral 22 of the end plate 21. An orbiting bearing 73 that connects the drive shaft 5 and the orbiting scroll 2 is provided on the boss 23. An eccentric pin 53 is integrally formed with the drive shaft 5, and a drive bush 54 is rotatably interposed in the eccentric pin 53. The drive bush 54 is rotatably interposed in the orbiting bearing 73 provided on the boss 23 of the orbiting scroll 2. A balance weight 84 is attached to the drive shaft 5.

Next, the flow of the refrigerant gas in this scroll compressor will be described. The low-temperature low-pressure refrigerant gas returned to the compressor is introduced into the space inside the housing 8 via the suction pipe 82, cools the electric motor 4, and then passes through a part of the outer periphery of the frame 6 to be provided on the fixed scroll 1. The suction passage 15 is introduced into a suction chamber 16 provided outside the fixed scroll 1.

The orbiting scroll 2 driven by the electric motor 4 is restricted by the rotation preventing member 3 and revolves, so that the fixed scroll 1 and the orbiting scroll 2 are provided with spirals 12 and 22, respectively, which are hermetically sealed. The space 24 gradually reaches the center of the scroll while decreasing its volume. During this time, the pressure and temperature of the refrigerant gas rises as the volume of the closed space 24 decreases, and the refrigerant gas is discharged from the discharge port 13 of the fixed scroll 1 to the discharge cavity 14 via the discharge valve 17, and the high temperature and high pressure in the discharge cavity 14 are discharged. The refrigerant gas is sent out of the compressor via the discharge pipe 83.

On the other hand, the lubricating oil 81 accumulated in the lower part of the housing 8 is the centrifugal pump 51 provided on the shaft 5.
Oil hole 52 provided eccentrically from the shaft center by
And a part of the oil is supplied to the lower bearing 72. Furthermore, the slewing bearing 7 is provided via the eccentric pin 53 of the drive shaft 5.
3, the thrust bearing 74 and the rotation preventing member 3 are lubricated to reach the frame chamber 61 of the frame 6, and further the upper bearing 71 is lubricated, and then discharged to the lower part of the housing 8 through the oil drain hole 62. It

[0010]

In the above-mentioned conventional structure, the lubricating oil 81 is used for lubricating the sliding parts of the compressor. However, the lubricating oil 81 causes the following problems. Was occurring. (1) Since part of the lubricating oil 81 is sent out to the refrigerant air conditioner together with the refrigerant gas, the condenser 92 and the evaporator 94
Enters inside and reduces heat transfer characteristics.

(2) The refrigerant containing lubricating oil has a larger flow pressure loss than the refrigerant alone, and a loss in the refrigerating and air-conditioning apparatus is caused by this pressure loss. (3) Since the lubricating oil 81 is always present in the compressor, the refrigerating and air-conditioning apparatus needs to occasionally perform control operation for returning the lubricating oil present in the condenser 92, the evaporator 94 and the pipe to the compressor.

(4) Since the lubricating oil has a property of dissolving in the refrigerant, when the refrigerating and air-conditioning system is stopped for a long time, the refrigerant preferentially dissolves in the lubricating oil in the compressor, and when the next compressor is started, Lubricating oil in which a large amount of refrigerant liquid has melted may be compressed, which may cause a problem of strength of the compressor.

The present invention provides a refrigerating and air-conditioning apparatus and a fluid machine suitable for the same, which eliminates the above-mentioned conventional problems by eliminating the need for lubricating oil for lubricating sliding parts of fluid machines such as compressors. The purpose is to

[0014]

In order to solve the above problems, the present invention has as its essence the lubrication of the sliding portion of a fluid machine by introducing a refrigerant liquid from a refrigerating and air-conditioning apparatus. That is, the present invention uses a refrigerant, and in a refrigerating and air-conditioning apparatus equipped with a fluid machine for carrying the refrigerant, a refrigerant solution that liquefies the refrigerant solution in the apparatus to a sliding portion of the fluid machine. It is characterized by having an introduction circuit.

In this case, the refrigerant liquid introducing circuit is connected to, for example, a refrigerant liquid line of a condenser for condensing and liquefying the refrigerant in the refrigerating and air-conditioning apparatus. Further, the present invention is a fluid machine comprising a suction / discharge mechanism for sucking / discharging a refrigerant and a rotary drive mechanism for driving the suction / discharging mechanism. It is characterized by having a liquid supply passage leading to a required sliding portion of the suction / discharge mechanism and the rotation drive mechanism.

[0016]

As described above, in the refrigerating air conditioner of the present invention, the lubricating oil is used by guiding the refrigerant liquid liquefied in the refrigerating air conditioner to the sliding portion of the fluid machine such as the compressor and utilizing it for lubrication. All of the conventional problems due to this are solved.

Further, in the fluid machine of the present invention, the liquid supply passage for guiding the refrigerant liquid introduced from the outside through the refrigerant liquid introduction circuit to the intake / exhaust mechanism and the required sliding portion of the rotary drive mechanism for driving the same. By providing the above, the sliding portion can be lubricated by the refrigerant liquid.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a refrigerating and air-conditioning apparatus according to an embodiment of the present invention. This refrigerating and air-conditioning apparatus is mainly composed of a compressor 100 which is a fluid machine for conveying a refrigerant, a condenser (condenser) 92, an expansion valve 93 and an evaporator (evaporator) 94. Here, between the condenser 92 and the compressor 100, a refrigerant liquid pipe 1 for returning a part of the refrigerant liquid in the condenser 92 to the compressor 100.
01 is different from the conventional configuration.

The high-temperature, high-pressure refrigerant gas discharged from the compressor 101 is condensed and liquefied by the condenser 92, and the expansion valve 9
After the pressure is reduced in 3, the refrigerant liquid is evaporated in the evaporator 94 and returns to the compressor 91. The heat generated by evaporation in the evaporator 94 is used during cooling, and the condenser 92 is used during heating.
The point that refrigeration and air conditioning is performed using the heat for liquefaction inside is the same as the conventional one. Then, a part of the refrigerant liquid condensed and liquefied by the condenser 92 is returned to the compressor 100 via the refrigerant liquid pipe 101, and the suction / exhaust mechanism and the rotation drive mechanism in the compressor 100 are slid as follows. Used for lubrication of moving parts.

FIG. 2 is a compressor provided with a liquid supply passage for guiding a refrigerant liquid introduced from the outside through a refrigerant liquid pipe 101 which is a refrigerant liquid introduction circuit to a required sliding portion of a suction / discharge mechanism and a rotation drive mechanism. It is sectional drawing which shows the structure of 100, and attaches | subjects the same code | symbol to the same part as FIG.

In FIG. 2, the main body of the scroll compressor is provided with a compression element portion at the upper portion and an electric motor at the lower portion. The compression element portion includes a fixed scroll 1, an orbiting scroll 2, and a rotation preventing member 3 that allows the orbiting of the orbiting scroll 2 and inhibits its rotation. In addition to these, a drive shaft 5 that connects the electric motor 4 and the compression element portion, a frame 6 that locks the fixed scroll 1 and the electric motor 4, an upper bearing 71 and a lower bearing 72 that support the drive shaft 5, An orbiting bearing 73 that rotatably supports the orbiting scroll 2 and a thrust bearing 74 that axially supports the orbiting scroll 2 are provided and housed in the housing 8. Unlike the conventional case, the housing 8 does not contain lubricating oil.

The fixed scroll 1 comprises an end plate 11 and a spiral 12 formed integrally therewith. The end plate 11 has a discharge port 13, a discharge valve 17, and a discharge cavity located on the opposite side of the spiral 12. 14 are provided.

The orbiting scroll 2 comprises an end plate 21 and a spiral 22 integrally formed with the end plate 21, and a boss 23 for driving the orbiting scroll 2 is located on the opposite side of the end plate 21 from the spiral 22. An orbiting bearing 73 that connects the drive shaft 5 and the orbiting scroll 2 is provided on the boss 23. An eccentric pin 53 is integrally formed with the drive shaft 5, and a drive bush 54 is rotatably interposed in the eccentric pin 53.
4 is rotatably interposed in a swivel bearing 73 provided on the boss 23 of the swivel scroll 2. A balance weight 84 is attached to the drive shaft 5.

The structural difference between the compressor of this embodiment shown in FIG. 2 and the conventional compressor shown in FIG. 5 is as follows. First, the motor case 1 provided on the electric motor 4
Reference numeral 06 denotes a refrigerant liquid passage 10 for guiding the refrigerant liquid for lubrication from the refrigerant liquid pipe 101 of FIG. 1 to the sliding portion of the compressor.
7, 108 are formed. Of these, the refrigerant liquid passage 108 is for flowing the refrigerant liquid into the upper bearing 71. Further, a refrigerant liquid passage 110 is also formed on the shaft 109 of the electric motor 4. Further, the lower bearing 11
A circumferential groove 112 that connects the refrigerant liquid passage 107 in the motor case 106 and the refrigerant liquid passage 110 in the shaft 109 is formed in the No. 1. Incidentally, the fitting 113
Is for pouring the refrigerant liquid from the refrigerant liquid pipe 101 into the refrigerant liquid passage 107 in the motor case 106 without leaking.

Next, the flow of the refrigerant gas in the scroll compressor shown in FIG. 2 will be described. Low temperature returned to the compressor
The low-pressure refrigerant gas is introduced into the space inside the housing 8 through the suction pipe 82, cools the electric motor 4, and then passes through a part of the outer periphery of the frame 6 through the suction passage 15 provided in the fixed scroll 1. It is introduced into a suction chamber 16 provided outside the fixed scroll 1.

Here, the orbiting scroll 2 driven by the electric motor 4 is restricted by the rotation preventing member 3 and revolves, thereby forming the spirals 12 and 22 of the fixed scroll 1 and the orbiting scroll 2, respectively. The enclosed space 24 reaches the central portion of the scroll while gradually reducing the volume. During this time, the pressure and temperature of the refrigerant gas rises as the volume of the closed space 24 decreases, and the refrigerant gas is discharged from the discharge port 13 of the fixed scroll 1 to the discharge cavity 14 via the discharge valve 17, and the high temperature and high pressure in the discharge cavity 14 are discharged. The refrigerant gas is sent out of the compressor via the discharge pipe 83.

On the other hand, the refrigerant liquid introduced from the condenser 92 of FIG. 1 into the compressor 100 through the refrigerant liquid pipe 101 is first introduced into the refrigerant liquid passage 107 in the motor case 106, and a part of the refrigerant liquid is introduced. It is supplied to the upper bearing 71 through a refrigerant liquid passage 108 communicating with the passage 107. The other part of the refrigerant liquid guided to the refrigerant liquid passage 107 is supplied to the lower bearing 111 and also guided to the refrigerant liquid passage 110 provided on the shaft 109 via the circumferential groove 112,
Further, it is supplied to the orbiting bearing 73, the thrust bearing 74 and the rotation preventing member 3 via the eccentric pin 53 of the drive shaft 5.

The refrigerant liquid returned to the sliding portion in the compressor for lubrication is evaporated into a refrigerant gas, which is sucked into the compression portion and sent out into the refrigerating and air-conditioning apparatus. In this way, the refrigerant is effectively used.

When the refrigerant liquid is used as the lubricating fluid for the sliding portion of the compressor as described above, it is desirable to design as follows. Figure 3, Sakurai and Hironaka; "Chemistry One Point 5"
Tribology Friction / lubrication / wear ”published by Kyoritsu Shuppan Co., Ltd., p. 38 shows the Stribeck diagram quoted from FIG.

Bearing operating conditions: Of the lubricating fluid viscosity η, speed V, and load F _N , the viscosity η is the viscosity of the refrigerant liquid used, and the speed V is determined by the rotational speed and shaft diameter of the compressor.
In addition, the load F _{N of the} compressor (to reduce the bearing load, for example, the length of the bearing is increased), and the surface roughness of the shaft and the bearing are appropriately selected so that the bearing operates in the fluid lubrication region.

Furthermore, if the bearing must be operated in the mixed lubrication or boundary lubrication region outside the fluid lubrication region, a partial contact is made between the shaft and the surface of the bearing, so that the shaft and the bearing material can be machined. Is determined so as to meet the predetermined life.

In the above embodiments, the lower bearing, the upper bearing and the drive bearing are shown as the places for feeding the refrigerant liquid in the sliding portion of the compressor, but the present invention is not limited to this, and it is not necessary. Accordingly, it is possible to appropriately adopt a structure in which the refrigerant liquid is sent to other places such as the Oldham ring.

Further, although the refrigerating compressor is shown as the fluid machine in the above embodiments, the application is not particularly limited as long as it is a fluid machine using a refrigerant as a medium fluid, such as a pump for conveying a refrigerant liquid. In addition, the present invention can be variously modified and implemented without departing from the scope of the invention.

[0034]

As described above, according to the present invention, the refrigerant liquid introduction circuit for guiding the refrigerant liquid liquefied and cooled by the condenser in the refrigerating and air-conditioning system to the sliding portion of the fluid machine such as the compressor is provided. By adopting a configuration that lubricates these sliding parts, the previously used lubricating oil becomes unnecessary,
All the problems caused by using lubricating oil are eliminated.
That is, specifically, the advantages listed below are obtained.

(1) The lubricating oil does not deteriorate the heat transfer characteristics of the condenser and the evaporator. (2) The problem of increased pressure loss caused by the presence of lubricating oil is solved.

(3) The control operation in the refrigerating and air-conditioning device for returning the lubricating oil to the compressor becomes unnecessary, and the original predetermined cooling or heating operation can always be performed. (4) If the refrigeration air conditioner is stopped for a long time, if the lubricating oil is present, the refrigerant preferentially dissolves in the lubricating oil in the compressor, so when the next compressor starts up, a large amount of the refrigerant liquid dissolves in the lubricating oil. Oil compression can cause compressor strength problems, but without the use of lubricating oil these problems are fundamentally eliminated.

(5) Since the oil supply pump conventionally provided in the compressor is unnecessary and the lubricating oil reservoir is not necessary,
The size and cost of the compressor can be reduced. At the same time, the accumulator, which was necessary in the refrigerating and air-conditioning system when using lubricating oil, is also unnecessary.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a refrigeration / air-conditioning apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a compressor according to the same embodiment.

FIG. 3 is a Stribeck diagram for explaining the embodiment.

FIG. 4 is a schematic configuration diagram of a conventional refrigeration / air-conditioning system.

FIG. 5 is a sectional view showing the configuration of a conventional compressor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixed scroll 2 ... Orbiting scroll 3 ... Rotation prevention member 4 ... Electric motor 5 ... Drive shaft 6 ... Frame 8 ... Housing 11 ... End plate 12 ... Swirl 13 ... Discharge port 14 ... Discharge cavity 15 ... Suction passage 16 ... Suction chamber 16 17 ... Discharge valve 21 ... End plate 22 ... Spiral 23 ... Boss 24 ... Sealed space 53 ... Eccentric pin 54 ... Drive bush 71 ... Upper bearing 72 ... Lower bearing 73 ... Slewing bearing 74 ... Thrust bearing 83 ... Discharge pipe 84 ... Balance weight 91 ... Compressor 92 ... Condenser 93 ... Expansion valve 94 ... Evaporator 95 ... Accumulator 100 ... Compressor 101 ... Refrigerant liquid piping 106 ... Motor case 107 ... Refrigerant liquid passage 108 ... Refrigerant liquid passage 109 ... Shaft 110 ... Refrigerant liquid passage 111 ... Lower bearing 112 ... Circumferential groove 113 ... Fitting

Claims (3)

[Claims] 1. A refrigerating and air-conditioning apparatus that uses a refrigerant and is equipped with a fluid machine for transporting the refrigerant, wherein the refrigerant liquid liquefied in the apparatus is guided to a sliding portion of the fluid machine. A refrigerating and air-conditioning apparatus having an introduction circuit. 2. The refrigerating and air conditioning apparatus according to claim 1, wherein the refrigerant liquid introducing circuit is connected to a refrigerant liquid line of a condenser for condensing and liquefying the refrigerant. 3. A suction / discharge mechanism for sucking / discharging a refrigerant,
In a fluid machine having a rotary drive mechanism for driving the suction / exhaust mechanism, a refrigerant liquid introduced from the outside through a refrigerant liquid introduction circuit is guided to a required sliding portion of the suction / discharge mechanism and the rotary drive mechanism. A fluid machine having a liquid supply passage.