JP6448698B2 - Screw fluid machinery - Google Patents

Description

  The present invention relates to a screw fluid machine that handles refrigerants such as HFC and HFO, natural refrigerants such as air and carbon dioxide, and other compressible gases.

  Screw fluid machines are widely used as refrigeration and air-conditioning compressors and air compressors. It is a major component of heat pump equipment such as air conditioners, chillers, and refrigerators. The social demand for energy saving is extremely strong, and high energy efficiency and high capacity are becoming increasingly important. Yes.

  In a conventional screw fluid machine, oil that has lubricated the shaft support means for rotatably supporting the rotor shafts of the male and female rotors flows into the suction port through the wall surface on the male rotor and female rotor side, and from the suction port. It is configured to be returned to the oil sump after mixing with the mainstream of the gas to be sucked.

  However, in the configuration of returning the oil of the conventional screw fluid machine, since the oil is mixed with the main flow of the gas sucked from the suction port, heat exchange is performed between the gas and the oil, and the intake air heating is increased. As a result, the compression efficiency is reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a screw fluid machine capable of reducing intake air heating by suppressing mixing of oil with a main stream of gas sucked from a suction port, and having high energy efficiency and high capacity. And

  In order to solve the above-described problem, a screw fluid machine according to an embodiment of the present invention includes a male rotor and a female rotor that rotate while meshing with each other, and a shaft support that rotatably supports a drive shaft of the male rotor and the female rotor. Means, driving means for driving the male rotor and female rotor, the male rotor, the female rotor, the shaft support means, a casing for housing the drive means, and oil supply for supplying oil to the shaft support means And the casing has an intermediate portion located between the drive means and the male rotor and the female rotor, and the intermediate portion has a male penetration through which the drive shaft of the male rotor passes. A hole, a female through hole penetrating the drive shaft of the female rotor, and a gas located in the lower side of the male through hole and the female through hole, and sucking gas from the drive means side to the male rotor and female rotor side And an oil drainage passage portion that communicates with the male through hole and the female through hole and returns the oil that lubricates the shaft support means to the drive means side, and lubricates the shaft support means. The oil passes through a male oil passage formed by the drive shaft of the male rotor passing through the male through hole and a female oil passage formed by the drive shaft of the female rotor passing through the female through hole. Then, it is caused to flow into the oil drainage passage portion and flow into the drive means side from the horizontal edge of the suction port.

  According to the present invention, it is possible to suppress the mixing of oil with the main stream of gas sucked from the suction port, to reduce intake air heating, and to provide a screw fluid machine having high energy efficiency and high capacity. it can.

The horizontal sectional view of the screw fluid machine concerning a 1st embodiment is shown. Sectional drawing along the AA line of FIG. 1 of the screw fluid machine in 1st Embodiment is shown. Sectional drawing along the BB line of FIG. 1 of the screw fluid machine in 1st Embodiment is shown. Sectional drawing along CC line of FIG. 1 of the screw fluid machine in 1st Embodiment is shown. Sectional drawing along the DD line of FIG. 4 of the screw fluid machine in 1st Embodiment is shown. Sectional drawing along CC line of FIG. 1 of the screw fluid machine in 2nd Embodiment is shown. Sectional drawing along CC line of FIG. 1 of the screw fluid machine in 3rd Embodiment is shown.

  Hereinafter, a screw fluid machine 1 according to a first embodiment of the present invention will be described with reference to the drawings.

  The overall configuration of the screw fluid machine 1 will be described with reference to FIGS.

  FIG. 1 is a horizontal sectional view of a screw fluid machine 1 according to the present embodiment, and FIG. 2 is a sectional view of the screw fluid machine 1 according to the first embodiment taken along line AA in FIG. FIG. 3 shows a cross-sectional view of the screw fluid machine 1 according to the first embodiment along the line BB in FIG. FIG. 4 shows a cross-sectional view of the screw fluid machine 1 according to the first embodiment along the line CC in FIG.

  As shown in FIG. 1, the screw fluid machine 1 includes a compression unit 2, a drive unit 3, and a casing 4 that houses the compression unit 2 and the drive unit 3. As shown in FIGS. 1 and 2, the screw fluid machine 1 operates in the intermediate portion 4 </ b> A after the gas sucked into the screw fluid machine 1 from the suction port 15 formed in the casing 4 passes through the motor 14. Suction from the suction port 10 of the chamber into the working chamber. The sucked gas is compressed and discharged from the discharge port 16 to the outside of the screw fluid machine 1 through the discharge port 11 of the working chamber.

  The compression unit 2 includes a male rotor 5 that is rotationally driven by a motor 14 that is driving means disposed in the drive unit 3, a female rotor 6 that rotates while meshing with the male rotor 5, and the male rotor 5 and the female rotor. 6, the shaft support means 12 a, 12 b, 13 a, 13 b, the oil supply means 17 of the suction side shaft support means, and the oil supply means (not shown) of the discharge side shaft support means.

  The male rotor 5 and the female rotor 6 are respectively provided with a male rotor shaft 5b and a female rotor shaft 6b as rotational axes. The suction side shaft support means 12 a is composed of two roller bearings that support the suction side of the male rotor shaft 5 b of the male rotor 5, and the discharge side shaft support means 12 b supports the discharge side of the male rotor shaft 5 b of the male rotor 5. Roller bearings and ball bearings. The suction side shaft support means 13 a is constituted by a roller bearing that supports the suction side of the female rotor shaft 6 b of the female rotor 6, and the discharge side shaft support means 13 b is a roller bearing that supports the discharge side of the female rotor shaft 6 b of the female rotor 6. And ball bearings.

  The casing 4 includes an intermediate part 4A located between the compression part 2 and the drive part 3. In the intermediate portion 4A, a male through hole 4b, a female through hole 4c, a suction port 10, and an oil discharge passage portion 20 are formed. A male oil passage 17d is formed in the male through hole 4b through the male rotor shaft 5b of the male rotor 5. The female rotor shaft 6b of the female rotor 6 passes through the female through hole 4c to form a female oil passage 17e. The suction port 10 is located below the male through hole 4b and the female through hole 4c and has end edges 10a and 10b in the horizontal direction. In addition, the suction port 10 is widely opened on the male rotor 5 side, and conversely, is narrowly opened on the female rotor 6 side.

  The working chamber is constituted by the tooth grooves 5 a and 6 a of the male rotor 5 and the female rotor 6, the bore (wall surface facing the radial direction of each rotor) 7 of the casing 4, the suction end face 8 of the casing 4, and the discharge end face 9 of the casing 4. A plurality are formed. Here, the casing 4 shown in FIG. 1 is shown as an integral structure as an example. However, the casing 4 is disposed between the compression unit 2 and the drive unit 3, or the compression unit 2 is provided with discharge side shaft support means of the male and female rotors. It may be a divided structure or the like divided by parts.

  Next, the configuration of the oil supply means 17 will be described in detail.

  The casing 4 is formed with an oil supply main path 17a and an oil supply branch path 17b as oil supply paths to the suction side shaft support means 12a of the male rotor 5 and the suction side shaft support means 13a of the female rotor 6. For the oil supply, for example, a method of supplying oil separated by an oil separator (not shown) or the like by a pressure difference is used, but another method may be used. On the male rotor 5 side, the oil supplied from the oil supply main branch passage 17a to the suction side shaft support means 12a does not flow out to the motor 14 side by the seal member 17c that prevents oil leakage to the motor 14 side, and supports the suction side shaft. After lubricating the means 12a, the male rotor shaft 5b of the male rotor 5 flows out to the male oil passage 17d formed by passing through the male through hole 4b of the intermediate portion 4A. On the female rotor 6 side, the oil supplied to the suction-side shaft support means 13a from the oil supply branch passage 17b lubricates the suction-side shaft support means 13a, and then the female rotor shaft 6b of the female rotor 6 becomes the female through hole 4c in the intermediate portion 4A. Flows out to the female oil passage 17e formed by penetrating.

  The oil drain passage 20 for guiding oil from the male oil passage 17d and the female oil passage 17e to the oil reservoir 21 will be described with reference to FIGS.

  FIG. 5 shows a cross-sectional view of the screw fluid machine 1 according to the first embodiment along the line DD in FIG.

  As shown in FIGS. 4 and 5, the suction end face 8 of the intermediate portion 4 </ b> A has a suction port 10 of the working chamber, a male suction groove 18 a on the male rotor side where the suction end face 8 is dug on the opposite rotor side, and the female rotor side. Female suction groove 18b. Further, an oil drain passage portion 20 is formed in the intermediate portion 4A.

  The suction port 10 is formed below the male rotor shaft 5a and the female rotor shaft 6b. The male suction groove 18a and the female suction groove 18b are formed along a part (outer part) of the outer periphery of the male rotor shaft 5a and the female rotor shaft 6b, respectively. A boundary 19a between the suction port 10 and the male suction groove 18a is located on the right side of the lower portion of the female rotor shaft 6b in FIG. 4, and a boundary 19b between the suction port 10 and the female suction groove 18b is formed on the female rotor shaft 6b. Located directly below. The boundaries 19a and 19b correspond to the edges 10a and 10b of the suction port 10 in the horizontal direction.

  The oil discharge passage portion 20 includes a communication passage 20a, a discharge passage 20b, a plug 20c, and a discharge groove 20d. The communication path 20 a, the discharge path 20 b, and the discharge groove 20 d extend in the horizontal direction, are formed by a single drilling operation on the casing 4, and the plug 20 c closes a hole on the outer surface of the casing 4. The communication passage 20a connects the lower portion of the male oil passage 17d and the lower portion of the female oil passage 17e. The discharge passage 20b connects the lower portion of the female oil passage 17e and the female suction groove 18b. That is, the discharge path 20b communicates with the female through hole 4c, extends to the side away from the male through hole 4b, and opens into the female suction groove 18b. The discharge groove 20d is formed by cutting the bottom surface of the female suction groove 18b because the oil discharge passage portion 20 is processed as a large-diameter hole. For this reason, when the oil drain passage portion 20 is processed as a small-diameter hole, the drain groove 20d is not formed.

  Most of the oil that lubricates the suction side shaft support means 12a and flows into the male oil passage 17d flows into the communication passage 20a, flows in the horizontal direction, flows out into the female oil passage 17e, and supports the suction side shaft in the female oil passage 17e. Most of the merged oil flows through the discharge passage 20b in the horizontal direction and is discharged to the female suction groove 18b. The oil discharged to the female suction groove 18b falls along the female suction groove 18b and flows into the oil reservoir 21 located on the motor 14 side from the end edge 10b of the suction port 10. Thus, the oil that has lubricated the suction side shaft support means 12a, 13a flows in the direction intersecting the vertical direction (horizontal direction in the present embodiment) by the oil discharge passage portion 20, and then the end of the suction port 10 It is configured to flow from the edge 10b to the motor 14 side.

  Therefore, the oil that has lubricated the suction side shaft support means 12a, 13a is returned to the motor 14 over the wall that forms the edge 10b of the suction port 10, so that the mainstream of the gas into which the oil is sucked from the suction port 10 Mixing can be suppressed and intake air heating can be reduced. Thereby, the screw fluid machine 1 having high energy efficiency and high capacity can be realized.

  Also, the oil lubricated by the suction side shaft support means 12a, 13a is caused to flow in the direction intersecting the vertical direction (horizontal direction in the present embodiment) by the oil drain passage 20 and dropped along the female suction groove 18b. By increasing the number of oil films present in the female suction groove 18b, the temperature of the oil can be lowered by heat exchange with the casing 4. As a result, the heating of the gas sucked from the suction port 10 can be reduced.

  The communication passage 20a of the oil discharge passage 20 communicates with the male through hole 4b and the female through hole 4c, and the discharge passage 20b of the oil discharge passage 20 communicates with the female through hole 4c and is separated from the male through hole 4b. It is comprised so that it may extend to the side to do. For this reason, since the communication path 20a and the discharge path 20b can be formed with a drill once with respect to the casing 4, the communication path 20a and the discharge path 20b can be formed easily.

  The motor 14 drives the male rotor 5 to rotate, and the discharge path 20b communicates with the female through hole 4c and extends to the side away from the male through hole 4b. Since the opening of the suction port 10 where the motor 14 is not provided becomes narrow as the casing 4 becomes smaller, the discharge path 20b is configured to extend from the female through hole 4c to the side away from the male through hole 4b. The oil temperature can be lowered by increasing the distance from the outlet of the discharge passage 20b to the inlet 10. Therefore, the heating of the gas sucked from the suction port 10 can be reduced.

  Next, a screw fluid machine 1 according to a second embodiment of the present invention will be described with reference to FIG. The same members as those of the screw fluid machine 1 according to the second embodiment are denoted by the same reference numerals, description thereof is omitted, and only different portions will be described.

  FIG. 6 shows a cross-sectional view of the screw fluid machine 1 according to the second embodiment along the line CC in FIG.

  As shown in FIG. 6, the suction port 10 is located at the center of the male rotor shaft 5b and the female rotor shaft 6b, and forms a target shape with respect to a surface that is orthogonal to the paper surface. In the intermediate portion 4A, a male drainage passage portion 50 and a female drainage passage portion 51 are formed in place of the drainage passage portion 20, and connect the lower portion of the male oil passage 17d and the lower portion of the female oil passage 17e. The communicating path 20a is not formed.

  The male drainage passage portion 50 is constituted by a male discharge passage 50a, a plug 50b, and a discharge groove 50c. The male discharge path 50 a and the discharge groove 50 c extend in the horizontal direction, are formed by machining the casing 4 with a drill, and the plug 50 b closes a hole on the outer surface of the casing 4. The male discharge passage 50a connects the lower portion of the male oil passage 17d and the male suction groove 18a. That is, the male discharge path 50a communicates with the male through hole 4b, extends to the side away from the female through hole 4c, and opens into the male suction groove 18a. The discharge groove 50c is formed by cutting the bottom surface of the male suction groove 18a because the male drain passage 50 is processed as a large-diameter hole.

  The female drainage passage 51 is constituted by a female discharge passage 51a, a plug 51b, and a discharge groove 51c. The female discharge path 51 a and the discharge groove 51 c extend in the horizontal direction and are formed by drilling the casing 4, and the plug 51 b closes the hole on the outer surface of the casing 4. The female discharge path 51a connects the lower part of the female oil path 17e and the female suction groove 18b. That is, the female discharge path 51a communicates with the female through hole 4c, extends to the side away from the male through hole 4b, and opens into the female suction groove 18b. The discharge groove 51c is formed by cutting the bottom surface of the female suction groove 18b because the female oil discharge passage 51 is processed as a large-diameter hole.

  Most of the oil that lubricates the suction side shaft support means 12a and flows into the male oil passage 17d flows in the horizontal direction through the male discharge passage 50a, and is discharged to the male suction groove 18a. The oil discharged to the male suction groove 18a falls along the male suction groove 18a and flows from the end edge 10a of the suction port 10 into the oil reservoir 21 located on the motor 14 side. Thus, the oil that has lubricated the suction-side shaft support means 12a flows in the direction intersecting the vertical direction (horizontal direction in the present embodiment) by the male drain passage 50, and then the edge of the suction port 10 It is configured to flow from 10a to the motor 14 side.

  Further, most of the oil that lubricates the suction side shaft support means 13a and flows into the female oil passage 17e flows in the horizontal direction through the female discharge passage 51a, and is discharged to the female suction groove 18b. The oil discharged to the female suction groove 18b falls along the female suction groove 18b and flows into the oil reservoir 21 located on the motor 14 side from the end edge 10b of the suction port 10. Thus, the oil that has lubricated the suction-side shaft support means 13a flows in the direction intersecting the vertical direction (horizontal direction in the present embodiment) by the female drain oil passage 51, and then the edge of the suction port 10 It is configured to flow from 10b to the motor 14 side.

  According to the screw fluid machine 1 of the present embodiment, since the male oil drain passage 50 on the male rotor 5 side and the female oil drain passage 51 on the female rotor 6 side are provided, both end edges 10a and 10b of the suction port 10 are provided. Therefore, heat exchange between the suction gas and the oil can be suppressed. Therefore, the screw fluid machine 1 having high energy efficiency and high capacity can be realized by reducing the intake air heating.

  Next, a screw fluid machine 1 according to a third embodiment of the present invention will be described with reference to FIG. The same members as those of the screw fluid machine 1 according to the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different portions will be described.

  FIG. 7: has shown sectional drawing along CC line of FIG. 1 of the screw fluid machine 1 in 3rd Embodiment.

  As shown in FIG. 7, the oil drainage that discharges oil below the suction port 10 to the surface that forms the female suction groove 18 b and is located below the female rotor shaft 6 b of the female rotor 6. A relief groove 40 is formed.

  Thereby, since oil is returned from the lower side than the suction port 10, it can further suppress that oil mixes with the main stream of the gas sucked from the suction port 10, and intake air heating can be further reduced. Thereby, the screw fluid machine 1 having higher energy efficiency and higher capacity can be realized.

  In addition, this invention is not limited to the Example mentioned above. A person skilled in the art can make various additions and changes within the scope of the present invention.

  For example, although the male rotor 5 is driven by the motor 14, the female rotor 6 may be driven. In this case, the oil drain passage 20 may be formed not in the female oil passage 17e but in the male oil passage 17d. Further, the oil drainage groove 40 may be formed in both the male suction groove 18a and the female suction groove 18b of the second embodiment.

1: screw fluid machine, 4: casing, 4A: middle part, 4b: male through hole, 4c: female through hole, 5: male rotor, 5b: male rotor shaft, 6: female rotor, 6b: female rotor shaft, 8 : End face, 10: suction port, 10a, 10b: edge, 12a, 13a: suction side shaft support means, 14: motor, 17: oil supply means, 17d: male oil passage, 17e: female oil passage, 18a: male suction Groove 18b: female suction groove, 20: oil drainage passage, 20a: communication passage, 20b: discharge passage, 50: male oil discharge passage, 50a: male discharge passage, 51: female oil discharge passage, 51a: female discharge Road

Claims (8)

A male rotor and a female rotor rotating while meshing with each other;
Shaft support means for rotatably supporting the drive shafts of the male rotor and the female rotor;
Driving means for driving the male rotor and the female rotor;
A casing for housing the male rotor, the female rotor, the shaft support means, and the drive means;
Oil supply means for supplying oil to the shaft support means,
The casing has an intermediate portion located between the driving means and the male rotor and the female rotor,
The intermediate portion includes a male through hole through which the drive shaft of the male rotor passes, a female through hole through the drive shaft of the female rotor, and gas from the drive means side to the male rotor and the female rotor side. A suction port for sucking, and an oil drain passage portion for returning the oil that lubricates the shaft support means to the drive means side in communication with the male through hole and the female through hole;
The oil that has lubricated the shaft support means is configured to return from the suction port to the drive means side so as to avoid gas passing through the suction port through the oil drain passage portion .
The suction port is located below the male through hole and the female through hole,
Oil that lubricates the shaft support means is formed by a male oil passage formed by the drive shaft of the male rotor penetrating the male through hole and a drive shaft of the female rotor penetrating the female through hole. A screw fluid machine that is caused to flow into the oil drainage passage portion through the female oil passage, and to flow into the drive means side from a horizontal edge of the suction port . The screw fluid machine according to claim 1 , wherein the oil drainage passage is configured to flow oil in a direction intersecting a vertical direction. The oil drainage passage portion communicates with the male through hole and the female through hole, communicates with the male through hole, extends toward a side away from the female through hole, or communicates with the female through hole. The screw fluid machine according to claim 1 , further comprising a discharge passage extending to a side away from the through hole. When the driving means rotationally drives the male rotor, the discharge path communicates with the female through hole and extends to a side away from the male through hole.
4. The screw fluid machine according to claim 3 , wherein, when the driving means rotationally drives the female rotor, the discharge path extends to a side that communicates with the male through hole and is separated from the female through hole. A male suction groove that communicates with one end of the suction port in the horizontal direction along a part of the outer periphery of the drive shaft of the male rotor, and the female A female suction groove communicating with the other end portion in the horizontal direction of the suction port along a part of the outer periphery of the drive shaft of the rotor is formed,
The screw fluid machine according to claim 3 , wherein the discharge passage of the oil discharge passage portion opens into the male suction groove or the female suction groove. The oil drainage passage portion communicates with the male through-hole and extends to a side away from the female through-hole, and a female discharge passage communicates with the female through-hole and extends toward the side away from the female through-hole. The screw fluid machine according to claim 1 , comprising: A male suction groove that communicates with one end portion of the suction port in the horizontal direction along a part of the outer periphery of the drive shaft of the male rotor on the end surface on the male rotor and female rotor side of the intermediate portion, and A female suction groove communicating with the other end portion in the horizontal direction of the suction port along a part of the outer periphery of the drive shaft of the female rotor is formed,
The screw fluid machine according to claim 6 , wherein the male discharge passage opens into the male suction groove, and the female discharge passage opens into the female suction groove. Oil is discharged to the lower side of the suction port in the surface that forms the male suction groove and / or the female suction groove and is located below the rotor shaft of the male rotor and / or the female rotor. The screw fluid machine according to claim 5 or 7 , wherein a drain oil relief groove is formed.

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