JP2003322093A - Screw type fluid machine and refrigerating device provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screw type fluid machine for improving operation performance by improving a compression action of fluid and a refrigerating device provided with the machine. <P>SOLUTION: Each bearing 7 and 9 located on a fluid introduction side of both rotors 5 and 6 having screw shapes is provided with each of seal mechanisms M1 and M2 constituted of seal rings 16a and 16b for preventing leakage of lubricating oil used for the bearings 7 and 9, shaft seals 15a and 15b and wall surfaces of wall parts 18 and 19. Each bearing 7 and 9 is provided with each of oil flow passages 17a and 17b to conduct lubricating oil by communicating the seal mechanisms M1 and M2 and a compression chamber formed by both of rotors 5 and 6. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw type fluid machine for compressing and discharging a fluid and a refrigerating apparatus including the same.

[0002]

2. Description of the Related Art A screw type fluid machine has been conventionally used as a compressor of a refrigeration system or a pump for discharging a fluid. The structure of the screw type compressor 1 (screw type fluid machine) used as the compressor of the refrigerating apparatus will be described with reference to FIG. In the figure, reference numeral 2 is a casing, 4 is a motor, 5 is a male rotor (rotor), and 7 and 8 are bearings arranged individually.

The casing 2 has the appearance of the screw type compressor 1, and is provided with a suction port 3 for introducing a refrigerant (fluid) and a discharge port 14 for discharging the refrigerant. Inside the casing 2, the motor 4,
A male rotor 5, a female rotor (not shown), an oil separator 13 and the like are housed.

The motor 4 is provided on the upstream side of the flow of the refrigerant in the casing 2 so as to be adjacent to the suction port 3. The motor 4 is composed of a rotor 4a located near the center and a cylindrical stator 4b located outside the rotor 4a.

The rotor 4a is connected to a rotating shaft 5a of a male rotor 5 which will be described later, so that the rotating motion of the rotating shaft 5a is generated.
It is transmitted to a. The stator 4b is the casing 2
It is fixed by being fitted to the inner wall surface of the. A gap 4c is provided between the rotor 4a and the stator 4b, and the coolant can flow through the gap 4c.
Further, a groove 2b through which the refrigerant can flow is also formed between the stator 4b and the casing 2.

The male rotor 5 is a cylindrical shaft provided with spiral uniform protrusions (threads) on the outer periphery thereof, and is integrally formed with the rotary shaft 5a. A plurality of bearings 7 and 8 are provided on both ends of the rotary shaft 5a, and the rotary motion of the male rotor 5 is supported by these bearings 7 and 8. In the configuration shown in the figure, two bearings 7 are provided on the refrigerant suction side of the male rotor 5, and a total of 6 bearings are provided on the discharge side.
Two bearings 8 are provided. In the figure, the female rotor provided on the back side of the male rotor 5 is also provided with a plurality of similar bearings. In this way, the male rotor 5 has the bearings 7,
8 is rotatably supported by the motor 4
It is driven to rotate according to the power output from the.

A female rotor arranged in parallel with the male rotor 5 (on the back side of the male rotor 5 in the drawing) has a cylindrical shaft similar to that of the male rotor 5 with spiral uniform projections on the outer periphery thereof. Is. Further, the projections of the female rotor are formed in opposite directions so as to be paired with the male rotor 5. Therefore, the male rotor 5 and the female rotor are used in the relationship of the male screw and the female screw, and the female rotor follows the rotational drive by the rotation of the male rotor 5.

As the two rotors are driven to rotate, one of the two end surfaces becomes a suction surface 11 for sucking the refrigerant, and the other becomes a discharge surface 12 for discharging the refrigerant. A second suction chamber 2c is formed between the suction surface 11 and the motor 4, and functions as a flow path for the refrigerant sucked from the suction surface 11. The above-mentioned refrigerant suction side bearing 7 (including the female rotor bearing) is positioned and fixed in a state of being accommodated in this second suction chamber.

A cylindrical oil separator 13 for introducing the discharged refrigerant is provided on the downstream side of the refrigerant with respect to the discharge surface 12.
Is equipped with. The oil separator 13 includes a male rotor 5,
It plays the role of separating the lubricating oil in the refrigerant used for the lubrication of the female rotor, the bearings 7, 8 and the like and for ensuring the hermeticity.

Next, the flow of the refrigerant in the screw type compressor 1 will be described. The refrigerant that has flowed from an evaporator (not shown) and has finished heat exchange with air is sucked from the suction port 3 provided in the casing 2, passes through the filter 3a, and is guided to the first suction chamber 2a. And this first
The refrigerant that has flowed into the suction chamber 2a is the rotor 4a of the motor 4.
Passing through the gap 4c formed between the stator 4b and the stator 4b and the groove 2b formed between the casing 2 and the stator 4b, and the second suction chamber 2 in front of the male rotor 5 and the female rotor.
Enter c.

When the refrigerant passes through the gap 4c and the groove 2b,
The heat generated from the motor 4 is taken away by heat exchange with the refrigerant, which cools the motor 4. As described above, the action of the refrigerant passing through the motor 4 and being guided to the second suction chamber 2c is
This is because a negative pressure is generated in c by the rotational drive of both rotors.

The refrigerant that has passed through the motor 4 is transferred to the second suction chamber 2c.
When the above condition is satisfied, the lubricating oil used for the bearing 7 is mixed with the refrigerant along the arrow A. Then, the refrigerant mixed with the lubricating oil enters between the two rotors from the suction surface 11 while being agitated by the suction action generated by the rotation of the two rotors. That is, the refrigerant and the lubricating oil enter the tooth spaces between the protrusions formed on the outer circumferences of both rotors. When both rotors rotate in this state, meshing starts from the suction surface 11 side, and the space of the tooth space in which the refrigerant has entered is closed.

As the rotation of both rotors further progresses, the refrigerant confined in the tooth space is compressed by narrowing the space and gradually guided to the discharge surface 12 which is the discharge side of the refrigerant. At the same time, refrigerant is sucked into the suction surface 11 and both rotors continue to rotate, so that refrigerant is continuously compressed. Then, by following the compression stroke with the lubricating oil mixed with the refrigerant, lubrication of both rotors,
The hermeticity at the time of compression is secured.

The refrigerant compressed by the two rotors flows from the discharge surface 12 through the discharge passage 2d formed in the casing 2, and through the hole 13a formed in the side wall of the oil separator 13 inside the oil separator 13. Flow into.
Then, the oil separator 13 removes the lubricating oil used for the lubrication and the hermeticity of both rotors and the lubrication of the bearings 7, 8 from the refrigerant.

The removed lubricating oil collects in the lower part of the oil separator 13 and is discharged to the outside of the oil separator 13 from the lubricating oil discharge port 13c formed in the lower part.
Then, the discharged lubricating oil flows in the casing 2 and is stored in an oil tank 2e formed in the lower portion of the casing 2.

The refrigerant from which the lubricating oil has been removed is discharged from the oil separator discharge port 13b into the casing 2, and discharged from the communicating discharge port 14 to a condenser (not shown).

[0017]

However, in the conventional screw type compressor 1 described above, the lubricating oil used for the bearing 7 and the like is the second suction chamber 2c as shown by the arrow A.
The structure is such that the refrigerant is discharged inside and the refrigerant flows between the rotors together with the lubricating oil. In other words, the lubricating oil, which has become hot due to the lubrication of the bearing 7, is sucked between the rotors to raise the temperature of the refrigerant before compression.

When the temperature of the refrigerant rises during the suction process, the volume of the refrigerant expands, which reduces the volumetric efficiency of the refrigerant introduced. When the volumetric efficiency of the refrigerant is reduced, the compression action in both rotors is reduced, and there is a problem that the operating performance of the screw type compressor 1 is reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a screw type fluid machine having improved operation performance by improving the compression action of a fluid, and a refrigerating apparatus including the same. And

[0020]

The present invention adopts the following means in order to solve the above problems. The invention according to claim 1 is a screw type fluid machine having a rotary shaft and a bearing, which is rotationally driven and has a screw-shaped rotor that compresses the introduced fluid.
Lubricating oil leakage preventing means for preventing leakage of lubricating oil used in the bearing is provided.

With this structure, the lubricating oil used for the bearing on the fluid introduction side is prevented from leaking to the outside by the lubricating oil leakage prevention means, and the fluid introduced into the rotor and the lubricating oil are mixed. It will not be done. Therefore, the temperature of the fluid introduced into the rotor is not affected by the lubricating oil,
The temperature rise of the fluid due to the lubricating oil is avoided. That is, the volumetric efficiency of the introduced fluid is improved.

According to a second aspect of the invention, in the screw type fluid machine according to the first aspect, an oil passage for communicating the lubricating oil by communicating the lubricating oil leakage prevention means with the outer circumference or the end surface of the rotor. It is characterized by being equipped with.

With this structure, the lubricating oil of the bearing collected by the lubricating oil leakage prevention means is brought into the outer circumference or the end surface of the rotor by lowering the temperature by conducting the oil passage. By sending the lubricating oil directly to the rotor,
The lubricating oil travels on the surface of the rotor and is unlikely to mix with the fluid compressed by the rotor.

According to a third aspect of the present invention, in the screw type fluid machine according to the first aspect, the lubricating oil leakage prevention means and the sealed compression chamber formed by the rotor are communicated with each other so that the lubricating oil is conducted. It is characterized in that it is provided with an oil flow path.

With this structure, the lubricating oil around the bearing collected by the lubricating oil leakage prevention means is introduced into the compression chamber formed by the rotor through the oil passage. The closed compression chamber means a closed compression space closed by rotation of the rotor. Then, the lubricating oil guided to the compression chamber flows on the surface of the rotor and is guided to the discharge side of the rotor together with the fluid in the compression chamber. In this way, the volumetric efficiency of the fluid in the compression chamber does not change even when the lubricating oil, which has become hot due to the lubrication of the bearings, is sent to the compression chamber. Compress.
At the same time, the rotor can be lubricated.

Since the compression chamber to which the oil flow path is connected moves due to the rotation of the rotor and becomes gradually higher in pressure toward the discharge side, the pressure state inside the compression chamber is increased in order to promote smooth introduction of the lubricating oil. It is desirable to connect the oil flow path to a low point.

According to a fourth aspect of the invention, in the screw type fluid machine according to any one of the first to third aspects, the lubricating oil leakage prevention means has a wall surface for fixing the bearing and the wall surface. And a seal member provided on both sides with the bearing sandwiched therebetween.

With such a structure, the lubricating oil used for the bearing is prevented from leaking to the outside by the seal members provided on both sides of the bearing and the wall surfaces fixing them.

According to a fifth aspect of the invention, a condenser for liquefying the refrigerant, an expansion mechanism for adiabatically expanding the refrigerant liquefied by the condenser, and an evaporator for vaporizing the refrigerant adiabatically expanded by the expansion mechanism are provided. And a compressor for compressing the refrigerant vaporized by the evaporator, wherein the compressor is the screw type fluid machine according to any one of claims 1 to 4. It is characterized by that.

With such a structure, the leakage of the lubricating oil, which has been heated to a high temperature due to the lubrication of the bearing, is avoided by the lubricating oil leakage prevention means, and the temperature of the lubricating oil is increased with respect to the refrigerant which is the fluid introduced from the evaporator. Stop getting involved. This prevents the temperature of the refrigerant from rising due to the lubricating oil, and improves the volumetric efficiency of the refrigerant during compression. Then, the compressed refrigerant is discharged to the condenser and circulates in the refrigeration system while following the refrigeration cycle.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing the configuration of the refrigerating apparatus of this embodiment. Further, FIG. 2 is a partial cross-sectional view illustrating the internal structure of the screw type compressor 1 used in the refrigerating apparatus of this embodiment. In FIG.
Reference numeral 1 is a screw type compressor (screw type fluid machine), 30 is a condenser, 40 is an expansion mechanism, 50 is an evaporator,
Reference numeral 60 denotes a refrigerant pipe. Further, in FIG. 2, reference numeral 4 is a motor, 5 is a male rotor, 6 is a female rotor, and 7 to 10.
Are bearings, 15a and 15b are shaft seals (sealing members), 16a and 16b are seal rings (sealing members), and 17a and 17b are oil passages.

As shown in FIG. 1, the refrigeration system includes a condenser 30 for liquefying a refrigerant (fluid), an expansion mechanism 40 for adiabatically expanding the refrigerant liquefied in the condenser 30 (hereinafter referred to as "liquid refrigerant"), An evaporator 50 for evaporating the refrigerant adiabatically expanded by the expansion mechanism 40 and a screw type compressor 1 for compressing the refrigerant evaporated by the evaporator 50 are provided, and these are connected to the refrigerant pipe 6
It is configured to be connected with 0.

The high-temperature, high-pressure refrigerant compressed by the screw type compressor 1 flows into the condenser 30, and the refrigerant exchanges heat with the outside air, whereby the heat in the refrigerant is deprived of the outside air and liquefied. . The liquid refrigerant accumulates in the liquid reservoir 31 at the bottom of the condenser 30, from which it is conducted to the expansion mechanism 40 through the refrigerant pipe 60.

The liquid refrigerant sent from the liquid reservoir 31 of the condenser 30 is adiabatically expanded by being throttled by the expansion mechanism 40. Then, the temperature of the liquid refrigerant is lowered, and the liquid refrigerant is sent to the evaporator 50 as a gas-liquid two-phase fluid. In the evaporator 50, the refrigerant exchanges heat with the indoor air to remove heat from the indoor air and cool the indoor air.
Then, the refrigerant is vaporized by taking away the heat in the room, and the vaporized refrigerant is guided into the screw type compressor 1 by the suction action of the screw type compressor 1.

Next, the screw type compressor 1 will be described with reference to FIG.
The configuration and function of will be described in detail. The motor 4 is
It is provided on the upstream side of the flow of the refrigerant in the casing 2 so as to be adjacent to the suction port 3. This motor 4
Is composed of a rotor 4a located on the center side and a cylindrical stator 4b located outside the rotor 4a.

The rotor 4a is connected to a rotary shaft 5a of a male rotor 5 which will be described later, and the stator 4b is fitted and fixed to the inner wall surface of the casing 2. There is a gap 4c between the rotor 4a and the stator 4b so that the refrigerant can flow. Further, a groove 2b through which the refrigerant can flow is also formed between the stator 4b and the casing 2.

The male rotor 5 is provided with a spiral uniform protrusion (thread) on the outer circumference of the shaft, and is formed integrally with the rotary shaft 5a. A plurality of bearings 7 and 8 are provided on both ends of the rotary shaft 5a, and the male rotor 5 is rotatably supported by the bearings 7 and 8. The power source for rotating the male rotor 5 is the motor 4 connected to the rotating shaft 5a, and the male rotor 5 is rotationally driven about the rotating shaft 5a according to the output of the motor 4.

Similar to the male rotor 5, the female rotor 6 is provided with spiral uniform protrusions on the outer circumference of the shaft. The direction of the projection of the female rotor 6 is different from that of the projection of the male rotor 5, and is formed in the opposite direction so as to be paired with the projection of the male rotor 5. Therefore, the male rotor 5 and the female rotor 6 are meshed with each other, and when the male rotor 5 rotates, the female rotor 6 follows and rotates. A rotary shaft 6a for the female rotor 6 is integrally formed on the female rotor 6, and a plurality of bearings 9 provided on both end sides of the rotary shaft 6a are formed.
The female rotor 6 is rotatably supported by 10.

As the rotors 5 and 6 are rotationally driven, one of both end surfaces thereof becomes a suction surface 11 (left side in the drawing) for sucking the refrigerant, and the other becomes a discharge surface 12 for discharging the refrigerant.

A cylindrical oil separator 13 for introducing the discharged refrigerant is provided on the downstream side of the refrigerant with respect to the discharge surface 12.
Is provided, and the lubricating oil used to lubricate the rotors 5 and 6 and the bearings 7 to 10 and ensure hermeticity is separated from the refrigerant.

Now, the screw type compressor 1 in this embodiment is provided with two sealing mechanisms M1 and M2 (lubricating oil leakage preventing means). These sealing mechanisms M1,
M2 is provided in each of the bearings 7 and 9 located on the refrigerant introduction side (left side of each rotor in the figure) with respect to each rotor 5 and 6, and is arranged so as to sandwich both sides of each of these bearings 7 and 9. The shaft seals 15a and 15b, the seal rings 16a and 16b, and the wall portions 18 and 19 for fixing the bearings 7 and 9 are formed.

The structure of the seal mechanism M1 provided on the male rotor 5 side will be specifically described. A wall portion 18 into which the two bearings 7 and 7 are fitted fixes both bearings 7 and 7 in the vicinity of the center thereof, and further, the male rotor 5 is sandwiched between the bearings 7 and 7.
The shaft seal 15a fitted to the side and the seal ring 16a fitted to the opposite side of the shaft seal 15a are fixedly provided.

The shaft seal 15a has been conventionally used, and has a structure that prevents the lubricating oil of the bearing 7 from leaking directly into the suction surface 11. The seal ring 16a also has a function equivalent to that of the shaft seal, and has a structure in which the lubricating oil of the bearing 7 does not leak to the second suction chamber 2c which is the outside. This seal ring 16a
The structure will be briefly described. An uneven surface is formed on the contact surface with the rotating shaft 5a to prevent leakage so that the lubricating oil is swept.

Therefore, the lubricating oil injected into the bearing 7 has the shaft seal 15 provided so as to close both sides of the bearing 7.
a and the seal ring 16a, and the wall portion 1 for fixing them
The wall surface of 8 separates the second suction chamber 2c from leakage.

The lubricating oil accumulated by the sealing mechanism M1 without leaking has a temperature of 80 due to the lubrication of the bearing 7.
Since it deteriorates as it rises above ℃, it is desirable to discharge and circulate it early depending on the operating conditions. For this reason, the oil passage 17a for discharging the lubricating oil in the seal mechanism M1 to the compression chamber described later is connected to the wall portion 18 which constitutes the seal mechanism M1.

The oil passage 17a is formed so as to penetrate the wall portion 18 so that the side connected to the seal mechanism M1 communicates with the vicinity of the seal ring 16a, and the side for discharging lubricating oil is formed on the outer periphery of the male rotor 5. It is formed so as to connect to the compression chamber. Explaining the compression chamber, in the compression chamber, the groove portion between the protrusions of the male rotor 5 and the female rotor 6 meshes the rotors 5 and 6 and the inside of the casing 2 that accommodates the rotors 5 and 6. It is a space enclosed by the wall surface W. The rotation of both rotors 5 and 6 causes the compression chamber to gradually move to the right side in the drawing, and at that time, the volume of the compression chamber decreases, whereby the refrigerant is compressed.

Therefore, the oil passage 17a communicates with the middle portion in the longitudinal direction of the male rotor 5 where the pressure is not relatively high, in order to smoothly discharge the lubricating oil. As a result, the lubricating oil that has finished lubrication of the bearing will be
Is transmitted to the outer periphery of the male rotor 5 to lubricate the male rotor 5 and to fill the gap between the protrusion of the male rotor 5 and the wall surface W to ensure hermeticity. At this time, the lubricating oil flows through the protrusions of the male rotor 5 and is transmitted without being directly mixed with the refrigerant.

As shown in this figure, the oil passage 17
The a is also branched and connected to the vicinity of the suction surface 11 on the outer circumference of the male rotor 5. This is to lubricate the outer circumferences of the male rotor 5 and the female rotor 6 on the suction surface 11 side. Although the lubricating oil is not delivered to the closed compression chamber, the temperature of the lubricating oil is slightly lowered by conducting the oil passage 17a. Can promote lubrication. In particular, as shown in the figure, the lubricating oil delivered directly to the male rotor 5 is
Since it is transmitted to the projections of No. 2 and flows, there is an advantage that it is difficult to mix and mix with the refrigerant.

Next, a sealing mechanism M provided on the female rotor 6 side
2 will be described. The seal mechanism M2 provided on the female rotor 6 side has substantially the same structure as the seal mechanism M1 on the male rotor 5 side described above, and the female rotor is sandwiched by the wall surface of the wall portion 19 fixing one bearing 9. A shaft seal 15b is fixed to the 6 side and a seal ring 16b is fixed to the opposite side.

The oil passage 17b formed through the wall portion 19 is connected to the outer periphery of the female rotor 6 near the middle in the longitudinal direction, and the lubricating oil that has finished lubricating the bearing 9 is the outer periphery of the female rotor 6. Is discharged to. The outer periphery of the female rotor 6 from which the lubricating oil is discharged faces the closed compression chamber formed by the engagement with the male rotor 5 and the wall surface W inside the casing 2. Also in the oil passage 17b on the female rotor 6 side, the suction surface 1 is formed similarly to the oil passage 17a on the male rotor 5 side.
1 is branched and connected to the vicinity of 1, and the intake side of the female rotor 6 is lubricated.

As described above, according to the screw type compressor of the present embodiment, the lubricating oil of the bearings 7 and 9 provided on the refrigerant suction side with respect to the rotors 5 and 6 is the second suction chamber. 2c does not leak out, and the refrigerant sucked from the suction surface 11 is not affected by the temperature of the lubricating oil. Therefore, the temperature rise of the refrigerant to be compressed is avoided as compared with the conventional case,
The volumetric efficiency of the refrigerant is improved and the refrigerant can be efficiently compressed. That is, it is possible to improve the operation efficiency of the screw compressor.

Further, as a result, the refrigerant discharged from the screw type compressor efficiently circulates in the refrigerating cycle, and it becomes possible to realize a refrigerating apparatus with improved operation performance.

Further, it becomes possible to properly guide the lubricating oil to both rotors 5 and 6, and while maintaining a high volumetric efficiency of the refrigerant introduced into both rotors 5 and 6, the rotational drive of both rotors 5 and 6 can be performed. It is possible to accurately perform lubrication, ensuring sealing performance, cooling, and rust prevention.

In the present embodiment, a refrigerating apparatus suitable for use in an air conditioner, a refrigerator, etc. has been described, but the present invention is not limited to this, and a screw type pump (screw type fluid) for discharging a fluid is used. Machine).

[0055]

The screw type fluid machine of the present invention and the refrigerating apparatus equipped with the same have the following effects. According to the first aspect of the invention, since the bearing located on the fluid introduction side is provided with the lubricating oil leakage prevention means for preventing the leakage of the lubricating oil used for the bearing, the fluid introduced to the rotor is The lubricating oil that has become hot due to the lubrication of the bearings is not mixed, and the volumetric efficiency of the fluid can be improved to improve the operating efficiency of the screw type fluid machine.

According to the second aspect of the present invention, since the lubricating oil leakage preventing means and the outer circumference or the end surface of the rotor are connected to each other so that the lubricating oil is electrically connected, the oil passage is electrically connected. It is possible to lower the temperature of the lubricating oil which has become high temperature. Further, even when the lubricating oil and the fluid are mixed at the time of compression, the lubricating oil is less likely to be mixed with the fluid by directly propagating on the surface of the rotor, and it is possible to avoid the temperature rise of the fluid and improve the volumetric efficiency. .

According to the third aspect of the present invention, since the lubricating oil leakage prevention means and the closed compression chamber formed by the rotor are communicated with each other, the oil passage is provided for conducting the lubricating oil.
The volumetric efficiency of the fluid to be compressed can be improved, and the rotor can be appropriately lubricated.

In the invention according to claim 4, since the lubricating oil leakage preventing means is constituted by the wall surface for fixing the bearing and the seal member fixed on the wall surface and provided on both sides with the bearing interposed therebetween, It is possible to reliably prevent the leakage of the lubricating oil of the bearing. Further, the structure of the lubricating oil leakage prevention means can be simplified, and it is possible to easily realize a screw type fluid machine with improved operation performance.

According to the invention of claim 5, since the screw type fluid machine according to any one of claims 1 to 4 is provided as one component of the refrigerating apparatus, the screw type fluid machine can be efficiently used. Refrigerant will be discharged,
It is possible to realize a refrigeration system with high operating efficiency and improved performance.

[Brief description of drawings]

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

FIG. 2 is a partial cross-sectional view of a screw type compressor which is a component of the refrigeration system according to the embodiment of the present invention.

FIG. 3 is a sectional view of a conventional screw type compressor.

[Explanation of symbols]

1 Screw type compressor (screw type fluid machine) 2 casing 2c Second suction chamber 4 motor 5a, 6a rotating shaft 7, 9 bearings 11 Suction surface 15a, 15b Each shaft seal 16a, 16b Each seal ring 17a, 17b Oil flow paths 30 condenser 40 Expansion mechanism 50 evaporator 60 refrigerant piping M1, M2 seal mechanism (lubricant oil leakage prevention means)

Claims (5)

[Claims] 1. A screw type fluid machine having a rotary shaft and a bearing, which is rotationally driven and has a screw-shaped rotor for compressing the introduced fluid, wherein the bearing located on the fluid introduction side is A screw type fluid machine comprising a lubricating oil leakage preventing means for preventing leakage of used lubricating oil. 2. The screw-type fluid according to claim 1, further comprising an oil passage for communicating the lubricating oil by connecting the lubricating oil leakage preventing means and the outer circumference or the end surface of the rotor. machine. 3. An oil flow path for communicating the lubricating oil by connecting the lubricating oil leakage prevention means and a closed compression chamber formed by the rotor to each other. Screw type fluid machinery. 4. The lubricating oil leakage prevention means is constituted by a wall surface fixing the bearing and seal members fixed to the wall surface and provided on both sides with the bearing interposed therebetween. The screw type fluid machine according to any one of claims 1 to 3. 5. A condenser for liquefying a refrigerant, an expansion mechanism for adiabatically expanding the refrigerant liquefied by the condenser, an evaporator for vaporizing the refrigerant adiabatically expanded by the expansion mechanism, and a vaporizer for the evaporator. In a refrigeration system including a compressor that compresses the refrigerant, the refrigeration system is characterized in that the compressor is the screw type fluid machine according to any one of claims 1 to 4. .