JP2017110517A - Screw fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide proper screw rotor cooling means in an oil cooled screw fluid machine to which oil is injected during a compression process.SOLUTION: As a constitution of cooling means for cooling inside of a male rotor 5 and a female rotor 6, the male rotor 5 has a male rotor internal hole 5a not penetrating through the inside of the male rotor 5. Further in the male rotor internal hole 5a, an internal passage portion 21a of a fixed cooling passage member 21 for the male rotor is disposed. The internal passage portion 21a is a part of the fixed cooling passage member 21 for the male rotor fixed to a motor casing cover 12, and is fixed to the motor casing cover 12, so that it is not rotated with the male rotor 5. A female rotor 6 side has the similar constitution.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an oil-cooled screw fluid machine that injects oil during a compression process, and more particularly to a screw fluid machine suitable for realizing high energy efficiency by cooling a screw rotor.

  Screw fluid machines are widely used as air compressors and compressors for refrigeration and air conditioning. In recent years, energy saving is strongly demanded in screw fluid machines, and high energy efficiency and high airflow (capacity) are becoming increasingly important.

  In improving the energy efficiency of a screw fluid machine, it is known that it is effective to cool a screw rotor that constitutes a working chamber. Further, it is known that it is effective to cool the inside of a rotor in a vacuum pump including two rotors.

  In Patent Document 1, in an oil-free screw compressor, a pair of meshing female and male rotors housed in a casing and a through-passage are respectively provided in the shafts in the axial direction. The nozzles are arranged in pairs, and both nozzles are communicated with a cooling lubricating oil passage that is sequentially provided with a flow rate control valve or a temperature control valve and an oil cooler, and the flow rate control valves are discharged to the rotors via a motor. It is connected to a temperature sensor provided in the port, or the temperature control valve is connected to the inlet side of the oil cooler, and the flow rate or temperature of the lubricating oil for cooling the rotor is controlled so that There is a description that the gap can always be kept constant and in a minimum state, and the performance of the compressor can be improved.

  In Patent Document 2, a two-shaft vacuum pump having two rotors is a type in which the rotor is cantilevered by a shaft, and the rotor is perforated hollowly. The cooling system is arranged at the height of the mating part between them, and the cooling system extends to the bearing so as to keep the bearing temperature low. There is a description that it can be operated with the amount of leakage.

JP 59-115492 A Special table 2004-506140 gazette

  As a cooling structure of the screw rotor, a hole structure penetrating the screw rotor in an oil-free screw fluid machine is known. Since it is an oil-free type, mixing of compressed gas and oil is not allowed. Therefore, in order to cause a cooling medium such as oil to flow in the through hole, an additional oil supply means that can pressurize the oil is required, which complicates the system. There is a problem.

  Patent Document 1 is an example of a through-hole structure in an oil-free screw fluid machine, and requires a separate oil supply means capable of boosting oil as described above, which complicates the system.

  In Patent Document 2, there is a description about a cooling path arranged in a rotor of a twin-shaft vacuum pump having two rotors, and the cooling path arranged in the rotor does not penetrate, but the oil reservoir at the bottom part is not filled with oil. In order to supply oil, a separate oil supply means capable of boosting the oil is necessary, and the system becomes complicated. Although the cooling pipe is provided with a dividing pipe, the dividing pipe is not fixed because it rotates together with the shaft, and this point is different from the fixed cooling passage in the present invention. Yes.

  An object of the present invention is to realize a screw rotor cooling means suitable for an oil-cooled screw fluid machine that injects oil during a compression process.

  In order to solve the above-mentioned problems, the present invention is characterized in that a male rotor and a female rotor rotating while meshing with each other, shaft support means for rotatably supporting the male rotor and the female rotor, and a male rotor and a female rotor are accommodated. A plurality of working chambers composed of a casing, a male rotor, a female rotor and a casing; oil injection means for injecting oil into the working chamber during the compression process; drive means for rotationally driving the male rotor or female rotor; In a screw fluid machine having a cooling hole formed inside a rotor and a female rotor, oil separation means for separating oil from compressed compressed gas, and cooling means for cooling the compressed compressed gas , A cooling medium for cooling the male rotor and the female rotor by the pressure difference between the high pressure generated by the screw fluid machine itself and a pressure lower than the high pressure is used as the male rotor and It is intended to flow in the cooling holes constituting the interior of the rotor.

  According to the present invention, the screw rotor cooling means in the oil-cooled screw fluid machine can be realized without the need for a separate oil supply means capable of boosting the oil, so that the oil-cooled screw fluid having high energy efficiency can be realized. The machine can be realized without complicating the system. Furthermore, by using a motor having an axial gap rotor, the diameter of the screw rotor can be increased, and the cooling hole area provided inside the screw rotor can be secured widely, so that the cooling effect of the screw rotor can be enhanced. It becomes possible. Further, when the screw fluid machine is of a vertical type and the oil separation means is integrally disposed at the lower part, the cooling means of the screw rotor is closer to the oil separation means and the oil separation means than those using through holes. Since the structure can be simplified by using the bearing portion as the communication space, an oil-cooled screw fluid machine having high energy efficiency can be realized without complicating the structure.

1 is a front view of a screw fluid machine according to Embodiment 1. FIG. The side view of the conventional screw fluid machine. The front view of the screw fluid machine which concerns on Example 2. FIG. FIG. 6 is a front view of a screw fluid machine according to a third embodiment. The front view of the screw fluid machine which concerns on Example 4. FIG. FIG. 10 is a front view of a screw fluid machine according to a fifth embodiment.

  Hereinafter, specific embodiments of the screw fluid machine of the present invention will be described with reference to the drawings. In each figure, the parts denoted by the same reference numerals indicate the same or corresponding parts.

  A screw fluid machine according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a front view of the screw fluid machine of the first embodiment, and FIG. 2 is a side view of a conventional screw fluid machine.

  The structure of Example 1 will be described. In FIG. 1, the screw fluid machine includes a compression unit 1 and a drive unit 2. The compression unit 1 constitutes a working chamber having a casing bore 4, a male rotor 5 and a female rotor 6 as basic members in the main casing 3, and is engaged with the male rotor 5 when the male rotor 5 is rotationally driven by the drive unit 2. The rotor 6 also rotates together to perform a compression operation. The gas sucked into the screw fluid machine passes through the suction port (not shown, corresponding to 7 in FIG. 2), is sucked into the working chamber, and after being compressed, the discharge port (not shown. (Equivalent to 8 in the above)). A D casing 9 is disposed on the discharge port side of the compression unit 1. In the D casing 9, the rotating shaft of the male and female rotors protrudes, and the discharge-side bearing portion 10 of the male rotor 5 and the discharge-side bearing portion 18 of the female rotor 6 that rotatably support the rotating shaft are disposed. . The suction-side bearing portion 15 of the male rotor 5 and the suction-side bearing portion 19 of the female rotor 6 are disposed on the drive portion 2 side of the main casing 3 and rotatably support the male rotor 5 and the female rotor 6. Yes. Further, the D casing lid 23 seals the anti-compression portion side of the D casing 9.

  In the drive unit 2, a motor 13 having an axial gap rotor that forms a gap in the axial direction and a motor-side rotary shaft 5 b of the male rotor 5 are disposed in a space formed by the motor casing 11 and the motor casing lid 12. The motor 13 having an axial gap rotor is composed of axial gap rotors 13a and 13b and a stator 13e. The axial gap rotors 13a and 13b are provided with magnets 13c and 13d, and the motor is arranged so as to sandwich the stator 13e. It is coupled to the side rotating shaft 5b. The axial gap rotors 13a and 13b may be configured on only one side.

  The configuration of the cooling means for cooling the inside of the male rotor 5 and the female rotor 6 will be described. The male rotor 5 has a male rotor inner hole 5 a that does not penetrate into the male rotor 5. Further, the internal passage portion 21a of the male rotor fixed cooling passage member 21 is disposed in the male rotor internal hole 5a. The internal passage portion 21 a is a part of the fixed cooling passage member 21 for the male rotor that is fixed to the motor casing lid 12, and is not rotated with the male rotor 5 because it is fixed to the motor casing lid 12. The internal passage portion 21a may be integrated with the male rotor fixed cooling passage member 21 or may be a separate assembly structure. Similarly, the female rotor 6 is also cooled by a female rotor fixed cooling passage member 22 having a female rotor inner hole 6a not penetrating into the female rotor 6 and an internal passage portion 22a disposed in the motor casing 11. Configure. The female rotor fixed cooling passage member 22 may be disposed not in the motor casing 11 but in the main casing 3, and even if not fixed to the motor casing 11 or the main casing 3, the female rotor 6 What is necessary is just to arrange | position so that it may not contact.

  In the first embodiment, oil separated from the compressed gas after discharge by the oil separation means 32 is used as a cooling medium for cooling the male rotor 5 and the female rotor 6. Here, the flow of oil as a cooling medium will be described. A gas 30 sucked from a suction port (not shown; corresponding to 7 in FIG. 2) is a working chamber formed in the main casing 3 and having a casing bore 4, a male rotor 5 and a female rotor 6 as basic members. Compressed. After completion of the compression, the compressed gas 31 mixed with the oil injected during the compression process is discharged. In addition to the oil injected during the compression process, the oil mixed with the compressed gas may be mixed with the oil that has lubricated the suction side bearing portions 15 and 19 and the discharge side bearing portions 10 and 18. The compressed gas 31 mixed with oil is separated into oil and compressed gas through the oil separation means 32. The oil passes through the oil cooling means 44 and is supplied from the supply passage 45a to the male rotor fixed cooling passage member 21 and the supply passage 45b to the female rotor fixed cooling passage member 22 to the internal passage portion of each rotor. It flows into 21a, 22a. The oil turns back at the ends of the inner holes 5a, 6a of each rotor and flows between the outer walls of the inner passage portions 21a, 22a of the rotors and the inner walls of the inner holes 5a, 6a of the rotors. It is discharged from the female rotor 6. The oil discharged from the male rotor 5 and the female rotor 6 passes through the motor casing lid 12 and the discharge passages 24 and 26 provided in the motor casing 11, and the discharge passages of the fixed cooling passage members 21 and 22 for each rotor. 45c and 45d, passing through the flow path 45e, and to the flow paths 45f and 45g for lubricating the suction side bearing portions 15 and 19 and the discharge side bearing portions 10 and 18, and the oil injection flow path 45h to the working chamber And distributed. The arrangement of the oil cooling means shown here is only an example, and it may be omitted if oil cooling is not necessary. Oil temperature control means may be disposed in the oil injection flow path 45h. Further, it is not always necessary to use the oil discharged from the fixed cooling passage members 21 and 22 for the lubrication of the bearing portion and the injection into the working chamber, and they may be constituted by different oil paths. Further, the flow direction of the oil as the cooling medium may be the reverse direction of 45a → 45c and 45b → 45d shown in FIG. In the first embodiment, the compressed gas separated from the oil is discharged from the discharge passage 36 through the gas cooling means 34 and the dehumidifying means 35.

  The arrangement of the shaft sealing means for the flow of oil as the cooling medium will be described. Here, the shaft seal means indicates a seal means for preventing intrusion of oil as a cooling medium. The shaft sealing means shown in FIG. 1 includes shaft sealing means 17 between the male rotor 5 and the motor casing 11, shaft sealing means 16 between the motor casing lid 12 and the male rotor fixed cooling passage member 21, and female sealing. Although there are three places of the shaft sealing means 20 between the rotor 6 and the motor casing 11, in the present invention, two places of the shaft sealing means 16 and 20 are necessary. The shaft sealing means 16 between the motor casing lid 12 and the male rotor fixed cooling passage member 21 is for preventing the oil that has cooled the male rotor 5 from flowing into the space of the motor 13. When oil flows into the motor space, there arises a problem that power increases due to stirring resistance. This is not always necessary if the amount of oil is small or a means for discharging the oil flowing into the motor chamber so as not to cause agitation in the motor is provided in the motor space. When a flow path for preventing oil agitation is provided in the motor space, a drain oil flow path 24 in the motor casing lid 12 is provided separately to the oil agitation prevention passage. The shaft sealing means 20 between the female rotor 6 and the motor casing 11 is for preventing the oil that has cooled the female rotor 6 from flowing into the space of the suction side bearing portion 19. The oil that has cooled the female rotor 6 may be directly used for lubricating the suction-side bearing portion 19 without passing through the oil discharge passage 45d. In this case, the shaft seal means 20 is not necessary.

  In addition to the configuration illustrated in FIG. 1, a motor casing lid 12 may be provided with a bearing portion that rotatably supports the motor-side rotating shaft 5 b on the side opposite to the compression portion of the motor 13. Further, although the motor 13 is illustrated as having a configuration having an axial gap rotor, it may be a motor having a radial gap rotor.

  Next, a comparison with the conventional structure will be made with reference to FIG. FIG. 2 shows a side view of an oil-free screw fluid machine as a conventional structure with only the compression unit 101. The compression unit 101 forms a working chamber having a casing bore 104, a male rotor 105, and a female rotor (not shown) as basic members in the main casing 103, and the male rotor 105 transmits the rotational force of the motor. When driven to rotate by the gear 132, the timing gear 131 for rotating the female rotor in a non-contact manner with the male rotor 5 also rotates, and the female rotor also rotates to perform the compression operation. The gas sucked into the screw fluid machine passes through the suction port 7 and is sucked into the working chamber. After being compressed, the gas is discharged through the discharge port 8. A D casing 109 is arranged on the discharge port side of the compression unit 101. A rotating shaft of the male and female rotors protrudes in the D casing 109, and a discharge-side bearing portion 110 of the male rotor 105 and a discharge-side bearing portion (not shown) of the female rotor that rotatably support the rotating shaft are disposed. Has been. The suction-side bearing portion 115 of the male rotor 105 and the suction-side bearing portion (not shown) of the female rotor are disposed on the speed increasing gear 132 side of the main casing 103 so that the male rotor 105 and the female rotor can rotate freely. I support it. Further, the D casing lid 123 seals the anti-compression portion side of the D casing 109, but a passage 140 for supplying oil that is a cooling medium for the rotor is provided. In cooling the rotor, a through hole 105a is provided in the rotor, and an oil supply pump 141 is provided outside. Oil as a cooling medium is pressurized by an external oil supply pump 141 and flows into the rotor internal through hole 105 a through the passage 140 provided in the D casing lid 123. The oil flowing into the rotor internal through hole 105a penetrates the rotor and is discharged from the speed increasing gear 132 side. As the oil shaft sealing means, a shaft sealing means 120 between the rotor and the speed increasing gear 132 and a shaft sealing means 121 between the rotor and the timing gear 131 are provided. Since it is an oil-free screw fluid machine, oil is not injected into the working chamber during the compression process, and oil that has lubricated the bearings 110 and 115 does not enter the working chamber. Therefore, when oil is allowed to flow as a cooling medium, a separate pressurizing means is required.

  The effect of Example 1 is demonstrated. In the first embodiment, when the screw rotor is cooled, it is possible to realize without oiling means that can pressurize the oil that is the cooling medium, so that an oil-cooled screw fluid machine having high energy efficiency can be realized. Can be realized without complicating the system. Further, by using a motor having an axial gap rotor as the motor, the passage area of the male rotor inner hole can be made larger than that of a motor having a radial gap rotor, so that the cooling action can be increased. This makes it possible to achieve even higher energy efficiency. Further, the oil that has finished cooling the female rotor is discharged directly to the suction-side bearing portion, whereby the rotor cooling portion structure can be simplified. Further, when the screw fluid machine is of a vertical type and the oil separation means is integrally disposed at the lower part, the cooling means of the screw rotor is closer to the oil separation means and the oil separation means than those using through holes. Since it is possible to simplify the structure by using the bearing as a communication space, an oil-cooled screw fluid machine with high energy efficiency can be realized without complicating the structure.

  Embodiment 2 of the screw fluid machine will be described with reference to FIG. In the description of the second embodiment, points different from the first embodiment will be mainly described, and the description of the same parts will be omitted.

  The difference from the first embodiment is that a compressed gas from which oil has been separated after discharge and that has passed through the gas cooling means 34 is used as a cooling medium for cooling the male rotor 5 and the female rotor 6. Here, the flow of the compressed gas after passing through the gas cooling means 34 as the cooling medium will be described. The compressed gas 31 mixed with oil is separated into oil and compressed gas through the oil separation means 32. The compressed gas passes through the gas cooling means 34, and is supplied from the supply flow path 50a to the fixed cooling passage member 51 for the male rotor and the supply flow path 50b to the fixed cooling passage member 22 for the female rotor. It flows into the parts 51a and 22a. The compressed gas is folded at the ends of the inner holes 5a, 6a of the rotors, flows between the outer walls of the inner passage portions 51a, 22a of the rotors and the inner walls of the inner holes 5a, 6a of the rotors. , Discharged from the female rotor 6. The compressed gas discharged from the male rotor 5 and the female rotor 6 passes through the fixed cooling passage member 51 for the male rotor and the discharge passages 54 and 26 provided in the motor casing 11, and then the fixed cooling passage member 51 for each rotor. , 22 reach the discharge flow paths 50c, 50d, pass through the flow path 50e, and return to the compressed gas flow path 50f. The compressed gas that has passed through the gas cooling means 34 does not need to flow in its entirety for cooling the rotor, but only needs to flow in the amount necessary for cooling. Further, the flow direction of the compressed gas as the cooling medium may be the reverse direction of 50a → 50c and 50b → 50d shown in FIG. In the second embodiment, the shaft sealing means between the motor casing lid 12 and the male rotor fixed cooling passage member 51 shown in the first embodiment is not necessary. This is because the shaft sealing means 17 between the male rotor 5 and the motor casing 11 is present, so that it is not necessary to prevent oil from entering the motor space.

  A specific effect of the second embodiment will be described. In Example 2, the number of shaft seals can be reduced by using compressed gas as the cooling medium, and the screw rotor cooling means can be configured at low cost by reducing the number of parts and simplifying the layout. become.

  Example 3 of the screw fluid machine will be described with reference to FIG. In the description of the third embodiment, the points different from the second embodiment will be mainly described, and the description of the same parts will be omitted.

  The difference from the second embodiment is that a compressed gas obtained by separating oil after discharge and used after passing through the dehumidifying means 35 is used as a cooling medium for cooling the male rotor 5 and the female rotor 6. The basic configuration of the supply and discharge flow paths in Example 2 is the same except that the compressed gas after passing through the dehumidifying means 35 is used. The compressed gas passes through the dehumidifying means 35 and is supplied from the supply flow path 60a to the fixed cooling passage member 51 for the male rotor and the supply flow path 60b to the fixed cooling passage member 22 for the female rotor. It flows into 51a, 22a. The compressed gas is folded at the ends of the inner holes 5a, 6a of the rotors, flows between the outer walls of the inner passage portions 51a, 22a of the rotors and the inner walls of the inner holes 5a, 6a of the rotors. , Discharged from the female rotor 6. The compressed gas discharged from the male rotor 5 and the female rotor 6 passes through the fixed cooling passage member 51 for the male rotor and the discharge passages 54 and 26 provided in the motor casing 11, and then the fixed cooling passage member 51 for each rotor. , 22 reach the discharge channels 60c, 60d, pass through the channel 60e, and return to the compressed gas channel 60f. Note that the compressed gas after passing through the dehumidifying means 35 does not need to be flowed for cooling the rotor, but may be flowed only for the amount required for cooling. Further, the flow direction of the compressed gas as the cooling medium may be the reverse direction of 60a → 60c and 60b → 60d shown in FIG.

  A specific effect of the third embodiment will be described. In the third embodiment, compared with the second embodiment, the compressed gas can be cooled to a lower temperature by using the compressed gas downstream of the dehumidifying means 35. Therefore, the cooling effect of the screw rotor is high, inexpensive, and It is possible to configure a high energy efficient screw rotor cooling means.

  Embodiment 4 of the screw fluid machine will be described with reference to FIG. In the description of the fourth embodiment, the points different from the first to third embodiments will be mainly described, and the description of the same parts will be omitted.

  The difference from the first to third embodiments is that the arrangement of the high pressure side and the low pressure side of the working chamber is reversed. In the fourth embodiment, the high pressure side of the working chamber is disposed on the drive unit 2 side, and the sucked gas 73 is sucked from the counter driving portion side of the working chamber, and the compressed gas 74 is compressed into the working chamber. It is discharged from the drive unit side. Therefore, since the high temperature portion of the screw rotor is generated on the high pressure working chamber side, the male rotor internal hole 75c, the female rotor internal hole 76c, the internal passage 71a of the male rotor fixed cooling passage member 71, and the female rotor fixed In the fourth embodiment, if the internal passage 72a of the type cooling passage member 72 is configured up to the vicinity of the high pressure side, which is the high temperature portion of the screw rotor, the screw rotor can be cooled efficiently and the structure can be simplified. This is a unique effect. In FIG. 5, the first embodiment is shown as a representative example of the structure different from the fourth embodiment.

  Embodiment 5 of the screw fluid machine will be described with reference to FIG. In the description of the fifth embodiment, the differences from the first to fourth embodiments will be mainly described, and the description of the same parts will be omitted.

  The difference from the first to fourth embodiments is a vertical screw fluid machine. The oil separation means 83 for separating oil from the compressed discharge gas is integrated in the lower part of the screw fluid machine, and the separated oil 84 is stored in the lower part of the screw fluid machine. By using a hole structure that does not penetrate the screw rotor cooling means, the structure can be simplified because the cooling medium of the screw rotor does not need to pass through the oil separation means 83 with respect to the through hole structure. Become. A characteristic effect of the fifth embodiment is that the screw rotor cooling means can be configured with a simple configuration when the oil separating means is configured as a single body in the vertical type and below the screw fluid machine.

1: compression part, 2: drive part, 3: main casing, 4: casing bore,
5, 75, 105: male rotor, 5a: male rotor internal hole,
6, 76: female rotor, 6a: female rotor internal hole,
7: suction port, 8: discharge port, 9: D casing,
10: discharge side bearing of male rotor, 11: motor casing, 12: motor casing lid,
13: Motor having an axial gap rotor,
13a, 13b: axial gap rotor, 13c, 13d: magnets, 13e: stator 15: suction side bearing portion of male rotor,
16: Shaft sealing means between the motor casing lid 12 and the fixed cooling passage member 21 for the male rotor,
17: Shaft sealing means between the male rotor 5 and the motor casing 11
18: discharge side bearing portion of female rotor, 19: suction side bearing portion of female rotor,
20: shaft sealing means between the female rotor 6 and the motor casing 11,
21: Fixed cooling passage member for male rotor,
21a: Internal passage portion of fixed cooling passage member for male rotor 22: Fixed cooling passage member for female rotor,
22a: Internal passage portion of fixed cooling passage member for female rotor 23: D casing lid, 24, 26: discharge passage, 30: gas to be sucked,
31: Compressed gas mixed with discharged oil, 32: Oil separation means, 34: Gas cooling means,
35: Dehumidifying means, 44: Oil cooling means, 45a, 45b: Supply flow path,
45c, 45d: discharge flow path, 45e, 45f, 45g, 45h: flow path,
105a: Rotor internal through hole, 131: Timing gear, 132: Speed increasing gear,
140: Oil passage, 141: External oil pump

Claims (12)

A male rotor and a female rotor that rotate while meshing with each other, shaft support means for rotatably supporting the male rotor and the female rotor, a casing that houses the male rotor and the female rotor, the male rotor, and the female rotor A plurality of working chambers comprising a rotor and the casing; oil injection means for injecting oil into the working chamber during a compression process; drive means for rotationally driving the male rotor or the female rotor; the male rotor; In a screw fluid machine having cooling means configured inside the female rotor, oil separation means for separating oil from compressed gas after compression, and cooling means for cooling the compressed gas after compression,
The cooling medium configured to cool the male rotor and the female rotor inside the male rotor and the female rotor by a pressure difference between a high pressure generated by the screw fluid machine itself and a pressure lower than the high pressure. A screw fluid machine, characterized by being caused to flow in the means. The screw machine according to claim 1,
The cooling means configured inside the male rotor and the female rotor is disposed in a hole that does not pass through the male rotor and the female rotor and inside the hole that does not pass through, and rotates together with the male rotor and the female rotor. A screw fluid machine characterized by comprising a cooling passage fixed without being fixed. A screw fluid machine according to claim 1 or 2,
A screw fluid machine, wherein a hole that does not penetrate through the male rotor and the female rotor is provided at the axial center of the male rotor and the female rotor. The screw fluid machine according to any one of claims 1 to 3,
The screw fluid machine, wherein the cooling medium reciprocates in the male rotor and the female rotor. A screw fluid machine according to any one of claims 1 to 4,
A screw fluid machine characterized in that oil returned to the screw fluid machine from the oil separating means is used as the cooling medium. A screw fluid machine according to claim 5,
The screw fluid machine, wherein the oil returned to the screw fluid machine from the oil separation means, which is the cooling medium, is cooled by the oil cooling means and then flows in the male rotor and the female rotor. A screw fluid machine according to any one of claims 5 or 6,
A screw fluid machine, wherein oil returned to the screw fluid machine from the oil separating means as the cooling medium is supplied to the shaft support means after cooling the inside of the male rotor and the female rotor. The screw fluid machine according to any one of claims 1 to 4,
A screw fluid machine using a low-temperature gas downstream of cooling means for cooling the compressed gas after compression as the cooling medium. A screw fluid machine according to any one of claims 1 to 4,
A screw fluid machine comprising a dehumidifying means for dehumidifying a compressed gas after compression, and using a low-temperature gas downstream from the dehumidifying means as the cooling medium. A screw fluid machine according to any one of claims 1 to 9,
A screw fluid machine using a flat magnet motor as the driving means. A screw fluid machine according to claim 10,
A screw fluid machine using a motor having an axial gap rotor that forms a gap in the axial direction as the flat magnet motor. The screw fluid machine according to any one of claims 1 to 11,
The screw fluid machine itself is of a vertical type, the driving means for rotationally driving the male rotor or the female rotor at the upper part, and the oil separating means at the lower part are arranged integrally with the screw fluid machine itself, and the oil separating means and the A screw fluid machine comprising a bearing portion close to an oil separating means as a communication space.

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