Rotary machine system and negative pressure unit

Abstract

To suppress that the lowering of pressure caused by an ejector extends up to a region other than an objective bearing device while suppressing the leakage of a lubricant from the bearing device.SOLUTION: A rotary machine system comprises a rotary machine having a rotor having a rotating shaft, a casing, and a bearing device for rotatably supporting the rotating shaft, a drain line for collecting a lubricant supplied to the bearing device, an oil tank for storing the lubricant which is collected through the drain line, and a negative pressure unit arranged in the middle of the drain line, and lowering pressure in the bearing device. The negative pressure unit comprises an oil inlet part connected to the drain line and communicating with the bearing device, an oil circulation pipe which forms a flow passage of the lubricant, and an ejector for lowering the pressure of the oil circulation pipe by extracting a gas in the oil circulation pipe via a suction port. The oil circulation pipe has an oil sump pipe which can store the lubricant at a downstream side of a flow direction of the lubricant with respect to the suction port.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to rotating machine systems and negative pressure units. [Background technology]

[0002] In a rotating machine, a bearing device that rotatably supports a rotating shaft is supplied with lubricating oil. In such a bearing device, the supplied lubricating oil may leak. In particular, when the rotating machine is an electric motor, the lubricating oil is likely to leak when the pressure in the bearing device increases. For this reason, the pressure in the bearing housing may be made negative by sucking the gas in the bearing device using a suction device or the like.

[0003] For example, Patent Document 1 discloses a bearing device having a bearing sealed in a housing by a contact seal, a lubricating oil supply means for supplying lubricating oil together with compressed air to the bearing, and an air suction means for sucking air from the housing. In this configuration, an ejector (air suction means) is used to ensure that the amount of air sucked from the space within the housing is greater than the amount of air sucked from the clearance of the bearing. This constantly creates a negative pressure in the space within the housing compared to the outside, preventing the lubricating oil from leaking out of the housing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-77851 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration described in Patent Document 1, the drop in pressure generated by the ejector extends not only to the target bearing device, but also to other parts, for example through the piping to which the ejector is connected, which may have adverse effects and require a design change.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a rotating machinery system and a negative pressure unit that can suppress leakage of lubricating oil from the bearing device while preventing the pressure drop caused by the ejector from extending to parts other than the target bearing device. [Means for solving the problem]

[0007] In order to solve the above problems, a rotating machine system according to the present disclosure includes a rotating machine including a rotor having a rotating shaft rotatable about an axis, a casing that covers the rotor from the outside in a radial direction centered on the axis, and a bearing device that rotatably supports the rotating shaft relative to the casing, a drain line that recovers lubricating oil supplied to the bearing device, an oil tank that stores the lubricating oil recovered through the drain line, and a negative pressure unit that is arranged midway along the drain line and reduces a pressure inside the bearing device, and the negative pressure unit reduces the pressure inside the bearing device by applying pressure to the drain line. an oil inlet portion connected to the drain line and communicating with the bearing device, an oil outlet portion connected to the drain line and communicating with the oil tank, an oil distribution pipe connecting the oil inlet portion and the oil outlet portion and forming a flow path for the lubricating oil, and an ejector having a suction port connected to the oil distribution pipe and extracting gas in the oil distribution pipe via the suction port to reduce the pressure of the oil distribution pipe, wherein the oil distribution pipe is located downstream of the suction port in the flow direction of the lubricating oil, and has an oil reservoir pipe capable of storing the lubricating oil vertically below the oil inlet portion and the oil outlet portion.

[0008] The negative pressure unit according to the present disclosure is a negative pressure unit arranged midway through a drain line that delivers lubricating oil supplied to a bearing device of a rotating machine to an oil tank, and comprises: an oil inlet portion connectable to the drain line and communicating with the bearing device; an oil outlet portion connectable to the drain line and communicating with the oil tank; an oil distribution pipe that connects the oil inlet portion and the oil outlet portion and forms a flow path for the lubricating oil; and an ejector having a suction port connected to the oil distribution pipe and extracting gas within the oil distribution pipe via the suction port to reduce the pressure of the oil distribution pipe, and the oil distribution pipe has an oil reservoir pipe that is located downstream of the suction port in the flow direction of the lubricating oil and is capable of storing the lubricating oil vertically below the oil inlet portion and the oil outlet portion. Effect of the Invention

[0009] The rotating machine system and negative pressure unit disclosed herein can suppress leakage of lubricating oil from the bearing device while preventing the pressure drop caused by the ejector from extending to other parts other than the targeted bearing device. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of a rotating machine system according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a cross-sectional view showing a configuration of a negative pressure unit of the rotating machine system according to the first embodiment. [Diagram 3] FIG. 11 is a cross-sectional view showing a configuration of a negative pressure unit of a rotating machine system according to a second embodiment. [Figure 4] FIG. 11 is a cross-sectional view showing a configuration of a negative pressure unit of a rotating machine system according to a modified example of the embodiment. [Diagram 5] FIG. 13 is a diagram showing a schematic configuration of a rotating machine system according to a modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments for implementing a rotating machine system and a negative pressure unit according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments.

[0012] (Configuration of Rotating Machine Systems) As shown in Fig. 1, the rotating machine system 1A mainly includes an electric motor (rotating machine) 2, a compressor 3, a transmission 4, an oil tank 6, a lubricating oil supply line 7, a drain line 8, and a negative pressure unit 100A. Note that the rotating machine system 1A of this embodiment includes one compressor 3 and one transmission 4, but is not limited to this configuration. The rotating machine system 1A may include a plurality of compressors 3 and a plurality of transmissions 4. Also, the rotating machine system 1A may have a structure in which the electric motor 2 and the compressor 3 are directly connected to each other without including the transmission 4.

[0013] (Motor configuration) The electric motor 2 is indirectly connected to the compressor 3 via a transmission 4. The electric motor 2 is a so-called motor, and is a rotating machine that drives the compressor 3. The electric motor 2 includes a rotor 21, a casing 25, and a bearing device 24.

[0014] The rotor 21 has a rotating shaft 22. The rotating shaft 22 extends in an axial direction Da in which the first axis C1 extends. The rotating shaft 22 is cylindrical and centered on the first axis C1. The rotating shaft 22 is rotatably supported by a bearing device 24. A permanent magnet (not shown) is fixed to the outer circumferential surface of the rotating shaft 22. The rotating shaft 22 has an output shaft 23 integrally formed at the other end in the axial direction Da (in which the first axis C1 extends). The output shaft 23 extends in the axial direction Da. The output shaft 23 is cylindrical and centered on the first axis C1.

[0015] The bearing device 24 supports the rotating shaft 22 rotatably around the first axis C1. The bearing device 24 has a first bearing device 24A and a second bearing device 24B. The first bearing device 24A is disposed at a position close to one end (first end) of the rotating shaft 22 in the axial direction Da. The second bearing device 24B is disposed at a position close to the other end (second end) of the rotating shaft 22 in the axial direction Da. The first bearing device 24A and the second bearing device 24B each have a radial bearing.

[0016] The casing 25 covers the rotor 21 from the outside in the radial direction centered on the first axis C1. The casing 25 has a stator that covers the rotating shaft 22 and the permanent magnets from the outside in the radial direction. The rotating shaft 22 is rotationally driven by an AC magnetic field generated by the stator.

[0017] (Compressor configuration) The compressor 3 is arranged next to the electric motor 2 at a distance in the axial direction Da. The compressor 3 compresses a working fluid taken in from the outside to generate compressed fluid. Note that the type and use of the compressed fluid generated by the compressor 3 are not limited here. The rotation of the output shaft 23 is transmitted to the compressor 3 of this embodiment via a transmission 4. The compressor 3 of this embodiment is, for example, a multi-stage centrifugal compressor. The compressor 3 includes a compressor rotor 33, at least one impeller (not shown), and a compressor bearing device 32.

[0018] The compressor rotor 33 extends along the second axis C2. The compressor rotor 33 has a cylindrical shape centered on the second axis C2. The second axis C2 is parallel to the first axis C1 and extends in the axial direction Da. The first axis C1 and the second axis C2 are disposed at positions offset from each other in a direction perpendicular to the axial direction Da. A plurality of impellers (not shown) are disposed on the outer circumferential surface of the compressor rotor 33 at intervals in the axial direction Da.

[0019] The compressor bearing device 32 supports the compressor rotor 33 rotatably around the second axis C2. The compressor bearing device 32 has a first compressor bearing device 32A and a second compressor bearing device 32B. The first compressor bearing device 32A is disposed at a position close to one end (first end) of the compressor rotor 33 in the axial direction Da. The second compressor bearing device 32B is disposed at a position close to the other end (second end) of the compressor rotor 33 in the axial direction Da. The first compressor bearing device 32A has a radial bearing. The second compressor bearing device 32B has a radial bearing and a thrust bearing.

[0020] (Transmission configuration) The transmission 4 transmits the rotation of the electric motor 2 to the compressor 3 by accelerating or decelerating it using a plurality of gears 43 and 44. The transmission 4 is disposed between the electric motor 2 and the compressor 3 in the axial direction Da. The transmission 4 of this embodiment has a transmission input shaft 41 connected to the output shaft 23, a transmission output shaft 42 connected to the compressor rotor 33, an input side gear 43, and an output side gear 44. The gears 43 and 44 are housed in a transmission casing 48. The input side gear 43 and the output side gear 44 mesh with each other.

[0021] The transmission input shaft 41 extends along the first axis C1. The transmission input shaft 41 rotates around the first axis C1 together with the output shaft 23. An input side gear 43 is fixed integrally to the transmission input shaft 41. The transmission output shaft 42 extends along the second axis C2. The transmission output shaft 42 rotates around the second axis C2 together with the compressor rotor 33. The transmission output shaft 42 extends parallel to the transmission input shaft 41 at a position shifted from the transmission input shaft 41 in a direction perpendicular to the axial direction Da. An output side gear 44 is fixed integrally to the transmission output shaft 42.

[0022] The transmission 4 transmits the rotation of a transmission input shaft 41, which rotates integrally with the output shaft 23, to the transmission output shaft 42 via two gears 43 and 44. As a result, the compressor rotor 33 rotates integrally with the transmission output shaft 42. In this way, the transmission 4 transmits the rotation of the output shaft 23 to the compressor rotor 33 by increasing or decreasing the speed.

[0023] (Oil tank configuration) The oil tank 6 stores lubricating oil M used in the electric motor 2, the transmission 4, and the compressor 3. The lubricating oil M in this embodiment lubricates the bearing device 24 (the first bearing device 24A and the second bearing device 24B), the compressor bearing device 32 (the first compressor bearing device 32A and the second compressor bearing device 32B), and gears and bearings (not shown) inside the transmission 4.

[0024] (Lubricant supply line configuration) The lubricant oil supply line 7 is a pipe that supplies lubricant oil M to the bearing device 24, the compressor bearing device 32, and the transmission 4. The lubricant oil supply line 7 includes a main supply line 70, a first supply line 71, a second supply line 72, and a third supply line 73.

[0025] One end of the main supply line 70 is connected to the oil tank 6. A first supply line 71, a second supply line 72, and a third supply line 73 are connected to the main supply line 70. A pump 75 is disposed in the main supply line 70. The pump 75 sends the lubricating oil M in the oil tank 6 to the first supply line 71, the second supply line 72, and the third supply line 73.

[0026] The first supply line 71 supplies the lubricating oil M to the bearing device 24. The first supply line 71 includes a first supply line 71A on one end side and a first supply line 71B on the other end side. The first supply line 71A on one end side connects the main supply line 70 to the first bearing device 24A. The first supply line 71B on the other end side connects the main supply line 70 to the second bearing device 24B. The lubricating oil M supplied through the first supply line 71 (the first supply line 71A on one end side and the first supply line 71B on the other end side) is used for lubrication in the bearing device 24 (the first bearing device 24A and the second bearing device 24B).

[0027] The second supply line 72 supplies the lubricating oil M to the compressor bearing device 32. The second supply line 72 includes a one-end second supply line 72A and an other-end second supply line 72B. The one-end second supply line 72A connects the main supply line 70 to the first compressor bearing device 32A. The other-end second supply line 72B connects the main supply line 70 to the second compressor bearing device 32B. The lubricating oil M supplied through the second supply line 72 (the one-end second supply line 72A and the other-end second supply line 72B) is used for lubrication in the compressor bearing device 32 (the first compressor bearing device 32A and the second compressor bearing device 32B).

[0028] The third supply line 73 supplies the lubricating oil M to the transmission 4. The third supply line 73 connects the main supply line 70 with the inside of the transmission casing 48 of the transmission 4. The lubricating oil M supplied through the third supply line 73 is used to lubricate the gears 43, 44, etc. in the transmission casing 48.

[0029] (Drain line configuration) The drain line 8 sends the lubricating oil M discharged from the bearing device 24, the compressor bearing device 32, and the transmission 4 to the oil tank 6. The drain line 8 includes a first drain line 81, a second drain line 82, a third drain line 83, and a lower drain line 85.

[0030] The first drain line 81 discharges the lubricating oil M from the bearing device 24. The first drain line 81 includes a first drain line 81A on one end side and a first drain line 81B on the other end side. The upper end of the first drain line 81A on one end side is connected to the first bearing device 24A. The first drain line 81A on one end side extends downward in the vertical direction Dv from the first bearing device 24A. The upper end of the first drain line 81B on the other end side is connected to the second bearing device 24B. The first drain line 81B on the other end side extends downward in the vertical direction Dv from the second bearing device 24B. The lubricating oil M used and discharged in the bearing device 24 (the first bearing device 24A and the second bearing device 24B) is discharged through the first drain line 81 (the first drain line 81A on one end side and the first drain line 81B on the other end side) to the lower drain line 85 on the lower side.

[0031] The second drain line 82 discharges the lubricating oil M from the compressor bearing device 32. The second drain line 82 includes a one-end second drain line 82A and an other-end second drain line 82B. The upper end of the one-end second drain line 82A is connected to the first compressor bearing device 32A. The one-end second drain line 82A extends downward in the vertical direction Dv from the first compressor bearing device 32A. The upper end of the other-end second drain line 82B is connected to the second compressor bearing device 32B. The other-end second drain line 82B extends downward in the vertical direction Dv from the second compressor bearing device 32B. The lubricating oil M used and discharged in the compressor bearing device 32 (first compressor bearing device 32A and second compressor bearing device 32B) is discharged downward through the second drain line 82 (one end side second drain line 82A and the other end side second drain line 82B) into the lower drain line 85 below.

[0032] The third drain line 83 discharges the lubricating oil M from the transmission 4. An upper end of the third drain line 83 is connected to a lower part of the transmission casing 48 of the transmission 4. The third drain line 83 extends downward in the vertical direction Dv from the lower part of the transmission casing 48 of the transmission 4. The lubricating oil M used and discharged in the transmission 4 is discharged through the third drain line 83 into a lower drain line 85 below.

[0033] (Bottom drain line configuration) The lower drain line 85 is disposed below the first drain line 81, the second drain line 82, and the third drain line 83. The lower drain line 85 allows the lubricating oil M discharged from the first drain line 81, the second drain line 82, and the third drain line 83 to flow toward the oil tank 6. The lower drain line 85 extends from the first drain line 81 toward the oil tank 6. The lower drain line 85 is a pipe extending in a straight line from a base end 85a, which is one end in the axial direction Da, to a tip end 85b, which is the other end. The lower drain line 85 is inclined obliquely downward from the base end 85a, which is closest to the first drain line 81A on one end side, toward the tip end 85b, which is closest to the oil tank 6, and has a predetermined water gradient. The lower drain line 85 is inclined obliquely downward from the base end 85a toward the tip end 85b with a gradient of, for example, about 1 / 25.

[0034] The lower end of the first drain line 81 (first drain line 81A on one end side, first drain line 81B on the other end side), the lower end of the second drain line 82 (second drain line 82A on one end side, second drain line 82B on the other end side), and the lower end of the third drain line 83 are each connected to the lower drain line 85.

[0035] The oil tank 6 is connected to a tip 85b of the lower drain line 85. The oil tank 6 collects the lubricating oil M collected through the drain line 8.

[0036] In such a rotating machine system 1A, the lubricating oil M discharged from the bearing device 24, the compressor bearing device 32, and the transmission 4 is discharged downward into a lower drain line 85 through a first drain line 81, a second drain line 82, and a third drain line 83. The lubricating oil M discharged into the lower drain line 85 flows from a base end portion 85a on the upstream side toward a tip end portion 85b on the downstream side due to the gradient of the lower drain line 85.

[0037] (Configuration of negative pressure unit) As shown in FIG. 2, the negative pressure unit 100A reduces the pressure inside the bearing device 24. The negative pressure unit 100A is disposed in the middle of the drain line 8. In this embodiment, the negative pressure unit 100A is disposed in the middle of the lower drain line 85. The negative pressure unit 100A is disposed downstream Dfd of the flow direction Df of the lubricating oil M in the lower drain line 85 from the first drain line 81. The negative pressure unit 100A is disposed upstream Dfu of the flow direction Df in the lower drain line 85 with respect to the second drain line 82 and the third drain line 83. That is, the negative pressure unit 100A is disposed in the lower drain line 85 between the position where the first drain line 81 and the lower drain line 85 are connected and the position where the second drain line 82 and the third drain line 83 and the lower drain line 85 are connected.

[0038] Here, the lower drain line 85 has an upstream lower drain line 851 located on the upstream side Dfu of the flow direction Df of the lubricating oil M with respect to the negative pressure unit 100A. The upstream lower drain line 851 is connected to the first drain line 81. Furthermore, the lower drain line 85 has a downstream lower drain line 852 located on the downstream side Dfd of the flow direction Df of the lubricating oil M with respect to the negative pressure unit 100A. The downstream lower drain line 852 is connected to the second drain line 82 and the third drain line 83.

[0039] Therefore, the negative pressure unit 100A is disposed between the upstream lower drain line 851 and the downstream lower drain line 852 in the flow direction Df. The negative pressure unit 100A reduces the pressure on the upstream side Dfu in the flow direction Df relative to the position where the negative pressure unit 100A is disposed. That is, the negative pressure unit 100A of this embodiment reduces the pressure inside the bearing device 24, the upstream lower drain line 851, and the first drain line 81. In this way, the negative pressure unit 100A is connected to the compressor bearing device 32 and the transmission 4, and is substantially connected only to the bearing device 24.

[0040] As shown in FIG. 2, the negative pressure unit 100A includes an oil inlet 101, an oil outlet 102, an oil circulation pipe 103, an ejector 110, a suction pipe 104, and a gas discharge pipe 107.

[0041] The oil inlet portion 101 can be connected to the drain line 8. Specifically, the oil inlet portion 101 in this embodiment is flange-connected to the upstream lower drain line 851. The oil inlet portion 101 communicates with the bearing device 24 (the first bearing device 24A and the second bearing device 24B) via the lower drain line 85, the first drain line 81, and the second drain line 82.

[0042] The oil outlet portion 102 can be connected to the drain line 8. Specifically, the oil outlet portion 102 in this embodiment is flange-connected to the downstream lower drain line 852. The oil outlet portion 102 communicates with the oil tank 6 via the lower drain line 85.

[0043] The oil distribution pipe 103 connects the oil inlet portion 101 and the oil outlet portion 102. The oil distribution pipe 103 forms a flow path of the lubricating oil M from the oil inlet portion 101 to the oil outlet portion 102. The oil distribution pipe 103 of this embodiment has an inlet pipe portion 1031, an oil reservoir pipe 105, and an outlet pipe portion 1032.

[0044] The inlet pipe section 1031 extends in the extension direction of the upstream lower drain line 851 from the oil inlet section 101 toward the downstream side Dfd of the flow direction Df of the lubricating oil M. The outlet pipe section 1032 extends in the extension direction of the downstream lower drain line 852 from the oil outlet section 102 toward the upstream side Dfu of the flow direction Df of the lubricating oil M.

[0045] The oil sump pipe 105 is disposed between the oil inlet 101 and the oil outlet 102. The oil sump pipe 105 is connected to the inlet pipe 1031 and the outlet pipe 1032. The oil sump pipe 105 stores the lubricating oil M that flows from the upstream lower drain line 851 into the inlet pipe 1031. The oil sump pipe 105 is capable of storing the lubricating oil M below the oil inlet 101 and the oil outlet 102 in the vertical direction Dv. The oil sump pipe 105 is located downstream Dfd of the flow direction Df of the lubricating oil M with respect to the suction port 114 of the ejector 110 described later. The oil sump pipe 105 of this embodiment includes a bottom connection portion 1051, an upstream extension portion 1052, and a downstream extension portion 1053.

[0046] The bottom connection part 1051 is located below the oil inlet part 101 and the oil outlet part 102 in the vertical direction Dv. The bottom connection part 1051 is inclined downward in the vertical direction Dv from the upstream side Dfu to the downstream side Dfd in the flow direction Df at a gradient of, for example, about 1 / 25. The bottom connection part 1051 is a region that faces the lubricating oil M entirely when the lubricating oil M is stored in the oil reservoir pipe 105. The bottom connection part 1051 has a discharge port 1059 that can be opened and closed in order to discharge the lubricating oil M during maintenance, etc.

[0047] The upstream extension portion 1052 is connected to the bottom connection portion 1051 at a position closer to the oil inlet portion 101 than the bottom connection portion 1051, via a curved portion 1054 which is a curved pipe. The upstream extension portion 1052 extends upward in the vertical direction Dv relative to the bottom connection portion 1051, inclined at a gradient that does not hinder the flow of the lubricating oil M. The upstream extension portion 1052 may extend straight upward in the vertical direction Dv from the bottom connection portion 1051. The upstream extension portion 1052 is a region at least part of which faces the lubricating oil M when the lubricating oil M is stored in the oil reservoir pipe 105.

[0048] The downstream extension portion 1053 is connected to the bottom connection portion 1051 at a position closer to the oil outlet portion 102 than the bottom connection portion 1051, via a curved portion 1055 which is a curved pipe. The downstream extension portion 1053 extends upward in the vertical direction Dv relative to the bottom connection portion 1051, inclined at a gradient that does not hinder the flow of the lubricating oil M. The downstream extension portion 1053 may extend straight upward in the vertical direction Dv from the bottom connection portion 1051. The downstream extension portion 1053 is a region at least part of which faces the lubricating oil M when the lubricating oil M is stored in the oil reservoir pipe 105.

[0049] The oil distribution pipe 103 further includes a suction pipe 104 and a connection pipe 108. The upper end of the suction pipe 104 is flange-connected to a suction port 114 of an ejector 110 described later. The suction pipe 104 is located on the upstream side Dfu in the flow direction Df with respect to the oil reservoir pipe 105. The suction pipe 104 and the upstream extension portion 1052 are integrally formed so that the lower end of the suction pipe 104 is connected to the upper end of the upstream extension portion 1052. The suction pipe 104 extends from the connection portion between the inlet pipe portion 1031 and the upstream extension portion 1052 upward in the vertical direction Dv, inclined at a gradient that does not hinder the flow of the lubricating oil M. The suction pipe 104 may extend straight upward in the vertical direction Dv.

[0050] The connecting pipe 108 is located on the downstream side Dfd in the flow direction Df with respect to the oil reservoir pipe 105. The connecting pipe 108 and the downstream extension portion 1053 are formed integrally such that the lower end of the connecting pipe 108 is connected to the upper end of the downstream extension portion 1053. The connecting pipe 108 extends from the connection portion between the downstream extension portion 1053 and the outlet pipe portion 1032 upward in the vertical direction Dv, inclined at a gradient that does not obstruct the flow of the lubricating oil M. The connecting pipe 108 may extend straight upward in the vertical direction Dv.

[0051] The ejector 110 extracts gas from the oil distribution pipe 103 to reduce the pressure of the oil distribution pipe 103. The ejector 110 of this embodiment has an ejector body 111, an external intake port 112, a discharge port 113, and a suction port 114. The ejector body 111 forms a flow path for the drive gas Gd supplied from the outside inside. An ejector nozzle 111s is arranged inside the ejector body 111. The ejector nozzle 111s extends linearly in a direction connecting the external intake port 112 and the discharge port 113. The external intake port 112 draws the drive gas Gd supplied from the outside into the inside of the ejector body 111 (ejector nozzle 111s). The discharge port 113 discharges the supplied drive gas Gd to the outside of the ejector body 111. The suction port 114 communicates with a space in which the ejector nozzle 111s is disposed within the ejector body 111. The suction port 114 is connected to the suction pipe 104. As a result, the suction port 114 is connected to the oil distribution pipe 103. Here, the length from the suction port 114 to the bottom connection part 1051 in the vertical direction Dv is set to a length L1 that allows an air layer to be formed in the suction pipe 104.

[0052] The driving gas Gd supplied from the outside flows through the ejector body 111 from the external suction port 112 toward the discharge port 113. The driving gas Gd passes through the ejector nozzle 111s in the ejector body 111, so that the inside of the ejector body 111 is brought to a negative pressure (a state lower than the pressure outside the ejector body 111). Specifically, the inside of the ejector body 111 is brought to a state close to a vacuum. As the pressure inside the ejector body 111 is reduced in this manner, gas is sucked into the ejector body 111 through the suction port 114 into the suction pipe 104. As a result, the ejector 110 utilizes the ejector effect to extract gas from the oil circulation pipe 103 and reduce the pressure of the oil circulation pipe 103.

[0053] The gas discharge pipe 107 connects the discharge port 113 and the oil circulation pipe 103. One end of the gas discharge pipe 107 is flange-connected to the discharge port 113. The other end of the gas discharge pipe 107 is flange-connected to the connection pipe 108. In this way, the other end of the gas discharge pipe 107 is connected to the oil circulation pipe 103 via the connection pipe 108 between the position where the lubricating oil M is stored in the oil reservoir pipe 105 and the oil outlet portion 102. The gas discharge pipe 107 sends the mixed gas Gm discharged from the discharge port 113 of the ejector body 111 into the oil reservoir pipe 105 at the downstream side Dfd of the flow direction Df of the lubricating oil M from the bottom connection portion 1051. The mixed gas Gm is a gas obtained by mixing the driving gas Gd in the ejector 110 and the gas sucked into the ejector body 111 from the suction port 114.

[0054] The gas discharge pipe 107 has a first straight pipe section 1071. The first straight pipe section 1071 extends linearly from the discharge port 113 in a direction connecting the external suction port 112 and the discharge port 113 in the ejector 110. The first straight pipe section 1071 extends a predetermined length L2. This length L2 is set so as to minimize pressure loss in the flow of the mixed gas Gm by not curving or bending the flow path of the mixed gas Gm discharged from the discharge port 113.

[0055] (Action and effect) In the rotating machine system 1A having the above configuration, the lubricating oil M discharged from the first bearing device 24A is sent to the upstream lower drain line 851 through the one-end first drain line 81A. Similarly, the lubricating oil M discharged from the second bearing device 24B is sent to the upstream lower drain line 851 through the other-end first drain line 81B. In this manner, the lubricating oil M discharged from the bearing device 24 passes through the upstream lower drain line 851 and is sent to the oil inlet portion 101. The lubricating oil M sent to the oil inlet portion 101 flows into the inlet pipe portion 1031. At this time, the lubricating oil M flows through the upstream lower drain line 851, the oil inlet portion 101, and the lower layer portion (region below the center of the piping) in the inlet pipe portion 1031. In other words, the upstream lower drain line 851, the oil inlet portion 101, and the lower layer portion in the inlet pipe portion 1031 are liquid layers in which the lubricating oil M exists. On the other hand, the upper layers (regions above the center of the piping) in the upstream lower drain line 851, the oil inlet portion 101, and the inlet pipe portion 1031 are gas layers.

[0056] Here, the negative pressure unit 100A includes an ejector 110 having a suction port 114 connected to the oil distribution pipe 103. The ejector 110 distributes the drive gas Gd from the external suction port 112 to the discharge port 113 in the ejector body 111. When the drive gas Gd passes through the ejector nozzle 111s in the ejector body 111, the pressure in the ejector body 111 decreases to a state close to a vacuum. As the pressure in the ejector body 111 decreases, the ejector 110 sucks the gas filling the gas layer in the oil distribution pipe 103 through the suction port 114. This reduces the pressure in the oil distribution pipe 103. As the pressure in the oil distribution pipe 103 decreases, the pressure in the upstream lower drain line 851 connected to the oil distribution pipe 103 decreases. Therefore, the pressure inside the first bearing device 24A connected to the upstream lower drain line 851 via the one-end first drain line 81A and the second bearing device 24B connected to the upstream lower drain line 851 via the other-end first drain line 81B also drops. This suppresses leakage of the lubricating oil M from the first bearing device 24A and the second bearing device 24B.

[0057] The lubricating oil M flows from the inlet pipe section 1031 into the oil reservoir pipe 105. In the upstream extension section 1052, the bottom connection section 1051, and the downstream extension section 1053 of the oil reservoir pipe 105, the lubricating oil M is stored in the portion below the oil inlet section 101 and the oil outlet section 102 in the vertical direction Dv. That is, the lubricating oil M is stored in the oil reservoir pipe 105 below the oil inlet section 101 and the oil outlet section 102 in the vertical direction Dv. The lubricating oil M stored in the oil reservoir pipe 105 overflows from the upper end of the downstream extension section 1053 into the outlet pipe section 1032 as if being pushed out by the newly supplied lubricating oil M. The overflowing lubricating oil M flows from the outlet pipe section 1032 through the downstream lower drain line 852 to the oil tank 6.

[0058] In this way, the oil reservoir pipe 105 is filled with the stored lubricating oil M (particularly, the bottom connection part 1051 is filled with the lubricating oil M), so that the oil distribution pipe 103 is liquid-sealed between the oil inlet part 101 and the oil outlet part 102. As a result, the inside of the oil distribution pipe 103 is sealed between the region on the upstream side Dfu in the flow direction Df with respect to the oil reservoir pipe 105 and the region on the downstream side Dfd in the flow direction Df with respect to the oil reservoir pipe 105 by the lubricating oil M stored in the oil reservoir pipe 105. Therefore, the pressure drop generated by the ejector 110 affects only the upstream lower drain line 851 through the suction pipe 104, and does not affect the downstream lower drain line 852. In other words, in the oil distribution pipe 103, the pressure drop generated by the ejector 110 does not spread to the region on the downstream side Dfd in the flow direction Df of the oil reservoir pipe 105. Therefore, while the pressure inside the bearing device 24 decreases, the pressure inside the compressor bearing device 32 and the transmission 4 does not decrease. In this way, it is possible to prevent the pressure decrease caused by the ejector 110 from affecting other parts than the target bearing device 24 while suppressing leakage of the lubricating oil M from the bearing device 24.

[0059] Furthermore, by placing such a negative pressure unit 100A midway along the drain line 8 and connecting it to the bearing device 24 and the oil tank 6, a rotating machine system 1A equipped with such a negative pressure unit 100A can be easily realized.

[0060] The oil reservoir pipe 105 also includes a bottom connection portion 1051, an upstream extension portion 1052 extending upward in the vertical direction Dv relative to the bottom connection portion 1051, and a downstream extension portion 1053 extending upward in the vertical direction Dv relative to the bottom connection portion 1051. As a result, the bottom connection portion 1051 is formed below the vertical direction Dv relative to the oil inlet portion 101 and the oil outlet portion 102. Therefore, the bottom connection portion 1051 makes it possible to easily form a structure capable of storing lubricating oil M with a simple configuration.

[0061] In addition, the length from the suction port 114 to the bottom connection part 1051 in the vertical direction Dv is set to a length L1 that allows an air layer to be formed in the suction pipe 104. This makes it possible to prevent the lubricating oil M, which is a liquid stored in the bottom connection part 1051, from being sent to the ejector 110 through the suction pipe 104.

[0062] The gas discharge pipe 107 is connected to the discharge port 113 of the ejector 110 and the oil circulation pipe 103. The gas discharge pipe 107 is connected to the oil circulation pipe 103 between the position where the lubricating oil M is stored in the oil reservoir pipe 105 and the oil outlet portion 102. The mixed gas Gm, which is a mixture of the driving gas Gd in the ejector 110 and the gas sucked into the ejector body 111 from the suction port 114, is discharged from the discharge port 113 to the gas discharge pipe 107. Therefore, the mixed gas Gm discharged from the discharge port 113 passes through the gas discharge pipe 107 and flows into the oil circulation pipe 103 between the position where the lubricating oil M is stored in the oil reservoir pipe 105 and the oil outlet portion 102. The gas sucked into the ejector body 111 from the suction port 114 contains mist-like lubricating oil M. Therefore, the mixed gas Gm discharged from the discharge port 113 may also be mixed with mist-like lubricating oil M sucked into the suction port 114. Even in such a case, the lubricating oil M mixed with the mixed gas Gm can be sent to the downstream lower drain line 852 and returned to the oil tank 6 without being discharged to the outside. Furthermore, the mixed gas Gm flowing from the gas discharge pipe 107 into the oil circulation pipe 103 can promote the flow of the lubricating oil M passing through the oil reservoir pipe 105 toward the oil tank 6.

[0063] In addition, the gas discharge pipe 107 has a first straight pipe section 1071 that extends linearly from the discharge port 113 for a predetermined length L2. As a result, in the region of the predetermined length L2 from the discharge port 113, there is no portion that causes pressure loss for the flow of the mixed gas Gm discharged from the discharge port 113 of the ejector 110. Therefore, the performance of the ejector 110 is prevented from being deteriorated. As a result, the gas in the oil distribution pipe 103 can be stably sucked through the suction port 114, and the pressure inside the bearing device 24 can be stably reduced.

[0064] Furthermore, in the rotating machine system 1A including the electric motor 2, the compressor 3, and the transmission 4, the negative pressure unit 100A is connected only to the bearing device 24 of the electric motor 2. This allows a drop in internal pressure to occur only in the bearing device 24, which has a larger clearance than the compressor bearing device 32 and the transmission 4. This makes it possible to suppress leakage of the lubricating oil M specifically in the bearing device 24, without affecting devices other than the bearing device 24, such as the compressor bearing device 32 and the transmission 4.

[0065] Second Embodiment Next, a second embodiment of the rotating machine system and the negative pressure unit according to the present disclosure will be described. In the second embodiment described below, components common to the first embodiment will be denoted by the same reference numerals in the drawings and will not be described. The second embodiment differs from the first embodiment in that it has a temperature sensor.

[0066] As shown in Figure 3, in a rotating machine system 1B according to the second embodiment, a negative pressure unit 100B includes an oil inlet section 101, an oil outlet section 102, an oil distribution pipe 103, an ejector 110, a suction pipe 104, a gas discharge pipe 107B, and a temperature sensor 120.

[0067] The gas discharge pipe 107B of the second embodiment has a first straight pipe section 1071 and a second straight pipe section 1072. The second straight pipe section 1072 extends upward in the vertical direction Dv from the position where the lubricating oil M is stored in the oil reservoir pipe 105 via the connecting pipe 108. The second straight pipe section 1072 extends in a straight line upward in the vertical direction Dv with respect to the downstream extension section 1053 so as to extend the connecting pipe 108 in the vertical direction Dv. The lower end of the second straight pipe section 1072 is flange-connected to the connecting pipe 108. The middle of the second straight pipe section 1072 is connected to an end of the first straight pipe section 1071 at a position not connected to the discharge port 113 (a position away from the ejector 110).

[0068] The temperature sensor 120 has a detection section 121 and a temperature visualizing section 122. The detection section 121 is capable of detecting the temperature of the lubricant M by contacting the tip of the detection section 121 with the lubricant M. The detection section 121 extends linearly. The tip of the detection section 121 is located in a region of the downstream extension section 1053 where the lubricant M is stored. In other words, the detection section 121 extends to the lubricant M located in the downstream extension section 1053 while being inserted through the second straight pipe section 1072 and the connection pipe 108.

[0069] The temperature visualizing part 122 is connected to the base end of the detection part 121. The detection result of the detection part 121 can be visually confirmed from outside the negative pressure unit 100B. The temperature visualizing part 122 is disposed outside the gas discharge pipe 107B. The temperature visualizing part 122 is supported by the second straight pipe part 1072. The temperature visualizing part 122 is connected to the upper end of the second straight pipe part 1072.

[0070] (Action and effect) According to the rotating machine system 1B including the negative pressure unit 100B having the above-mentioned configuration, in addition to the same effects as those of the first embodiment described above, the gas discharge pipe 107B has a second straight pipe section 1072 extending upward in the vertical direction Dv from the position where the lubricating oil M is stored in the oil reservoir pipe 105. The linearly extending detection section 121 is disposed in a state passing through the second straight pipe section 1072. This makes it possible to easily dispose the temperature sensor 120 having the linearly extending detection section 121. Therefore, the temperature of the lubricating oil M stored in the oil reservoir pipe 105 can be detected with a simple configuration.

[0071] (Other embodiments) Although the embodiments of the present disclosure have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not depart from the gist of the present disclosure are also included.

[0072] For example, in the above first and second embodiments, the oil reservoir pipe 105 is configured to include a bottom connection portion 1051, an upstream extension portion 1052, and a downstream extension portion 1053, but is not limited to such a configuration.

[0073] 4, the negative pressure unit 100C of the rotating machine system 1C may have, as the oil reservoir pipe 105C, an upstream curved portion 1057 curved downward in the vertical direction Dv from the inlet pipe portion 1031, and a downstream curved portion 1058 curved upward in the vertical direction Dv continuously from the upstream curved portion 1057 and connected to the outlet pipe portion 1032. Such an oil reservoir pipe 105C is formed so as to be looped in a spiral shape by the upstream curved portion 1057 and the downstream curved portion 1058. By looping the oil reservoir pipe 105C in this way, the negative pressure unit 100C can be made compact in the direction connecting the oil inlet portion 101 and the oil outlet portion 102.

[0074] In each embodiment, the suction pipe 104 extends upward from the connection between the inlet pipe section 1031 and the upstream extension section 1052, but is not limited to such a configuration. For example, as shown in Fig. 4, the suction pipe 104C may extend upward from the middle of the inlet pipe section 1031 as long as it is connected to the oil distribution pipe 103C on the upstream side Dfu in the flow direction Df with respect to the oil reservoir pipe 105C.

[0075] In addition, in each embodiment, the gas discharge pipe 107 is provided to connect the ejector 110 and the oil circulation pipe 103, but the present invention is not limited to such a configuration. As shown in Fig. 4, the gas discharge pipe 107 may not be provided, and the mixed gas Gm discharged from the discharge port 113 of the ejector 110 may be discharged to a place other than the oil circulation pipe 103, such as the outside of the negative pressure unit 100C.

[0076] In the above embodiment, the negative pressure units 100A-100C are connected to the lower drain line 85 of the drain line 8 on the downstream side Dfd of all the first drain lines 81 in the flow direction Df, but the present invention is not limited to such a structure. For example, as shown in FIG. 5, the negative pressure units 100A-100C may be individually arranged to correspond to the bearing devices 24, respectively. That is, the negative pressure units 100A-100C may be connected to the upstream side Dfu of the lower drain line 85 in the flow direction Df, respectively, in the middle of the first drain line 81. That is, the negative pressure units 100A-100C may be separately arranged in the middle of the first drain line 81A on one end side and the first drain line 81B on the other end side.

[0077] In the above embodiment, the electric motor 2 is used as an example of the rotating machine, but the rotating machine may be, for example, a turbine. In this case, the rotating machine system may include a generator driven by the turbine, instead of the compressor 3.

[0078] <Additional Notes> The rotating machine systems 1A to 1C and the negative pressure units 100A to 100C described in the embodiment can be understood, for example, as follows.

[0079] (1) A rotating machine system 1A to 1C according to a first aspect includes a rotating machine 2 including a rotor 21 having a rotating shaft 22 rotatable around an axis C1, a casing 25 covering the rotor 21 from the outside in the radial direction centered on the axis C1, and a bearing device 24 rotatably supporting the rotating shaft 22 with respect to the casing 25, a drain line 8 that recovers lubricating oil M supplied to the bearing device 24, an oil tank 6 that stores the lubricating oil M recovered through the drain line 8, and negative pressure units 100A to 100C that are arranged midway along the drain line 8 and reduce a pressure inside the bearing device 24. The negative pressure units 100A to 100C are connected to the drain line 8 and are arranged in a front-to-rear direction. The oil distribution pipe 103 is provided with an oil inlet portion 101 communicating with the bearing device 24, an oil outlet portion 102 connected to the drain line 8 and communicating with the oil tank 6, an oil circulation pipe 103 connecting the oil inlet portion 101 and the oil outlet portion 102 and forming a flow path for the lubricating oil M, and an ejector 110 having a suction port 114 connected to the oil circulation pipe 103 and extracting gas in the oil circulation pipe 103 via the suction port 114 to reduce the pressure of the oil circulation pipe 103, and the oil circulation pipe 103 is located downstream Dfd of the flow direction Df of the lubricating oil M with respect to the suction port 114, and has oil reservoir pipes 105, 105C capable of storing the lubricating oil M below the oil inlet portion 101 and the oil outlet portion 102 in the vertical direction Dv.

[0080] As a result, the ejector 110 sucks the fluid in the oil distribution pipe 103 through the suction port 114. As a result, the pressure in the oil distribution pipe 103 decreases. As the pressure in the oil distribution pipe 103 decreases, the pressure in the drain line 8 connected to the oil distribution pipe 103 decreases. Therefore, the pressure inside the bearing device 24 also decreases through the drain line 8. As a result, leakage of the lubricating oil M from the bearing device 24 is suppressed. In addition, the lubricating oil M sent to the oil inlet portion 101 flows into the oil reservoir pipe 105. In the oil reservoir pipe 105, the lubricating oil M is stored in a portion below the oil inlet portion 101 and the oil outlet portion 102 in the vertical direction Dv. In this way, the oil reservoir pipe 105 is filled with the stored lubricating oil M, and the oil distribution pipe 103 is liquid-sealed between the oil inlet portion 101 and the oil outlet portion 102. Therefore, in the oil distribution pipe 103, the pressure drop caused by the ejector 110 does not affect the region Dfd downstream of the oil sump pipe 105 in the flow direction Df. Therefore, while the pressure inside the bearing device 24 drops, the pressure in the region Dfd downstream of the oil sump pipe 105 in the flow direction Df does not drop. In this way, it is possible to prevent the pressure drop caused by the ejector 110 from spreading to other parts other than the target bearing device 24 while suppressing leakage of the lubricating oil M from the bearing device 24.

[0081] (2) The rotating machinery systems 1A and 1B of the second aspect are the rotating machinery systems 1A and 1B of (1), wherein the oil reservoir pipe 105 comprises a bottom connection portion 1051 located below the oil inlet portion 101 and the oil outlet portion 102 in the vertical direction Dv, an upstream extension portion 1052 connected to the bottom connection portion 1051 at a position close to the oil inlet portion 101 and extending upward in the vertical direction Dv relative to the bottom connection portion 1051, and a downstream extension portion 1053 connected to the bottom connection portion 1051 at a position close to the oil outlet portion 102 and extending upward in the vertical direction Dv relative to the bottom connection portion 1051.

[0082] As a result, the bottom connection portion 1051 is formed below the oil inlet portion 101 and the oil outlet portion 102 in the vertical direction Dv. Therefore, the bottom connection portion 1051 makes it possible to easily form a structure capable of storing the lubricating oil M with a simple configuration.

[0083] (3) The rotating machine systems 1A and 1B according to a third aspect are the rotating machine systems 1A and 1B of (2), wherein the oil distribution pipe 103 further has a suction pipe 104 connecting the suction port 114 and the upstream extension portion 1052, and the length from the suction port 114 to the bottom connection portion 1051 in the vertical direction Dv is a length L1 capable of forming an air layer in the suction pipe 104.

[0084] This makes it possible to prevent the lubricating oil M, which is a liquid stored in the bottom connection portion 1051, from being sent to the ejector 110 through the suction pipe 104.

[0085] (4) The rotating machine system 1A, 1B of the fourth aspect is any one of the rotating machine systems 1A, 1B of (1) to (3), and further includes a gas discharge pipe 107 connected to the oil circulation pipe 103 and an outlet 113 from which the drive gas Gd supplied in the ejector 110 is discharged, and the gas discharge pipe 107 is connected to the oil circulation pipe 103 between the position where the lubricating oil M is stored in the oil reservoir pipe 105 and the oil outlet portion 102.

[0086] As a result, the gas discharged from the discharge port 113 passes through the gas discharge pipe 107 and flows into the oil circulation pipe 103 between the position where the lubricating oil M is stored in the oil reservoir pipe 105 and the oil outlet part 102. The gas sucked into the ejector 110 from the suction port 114 contains mist-like lubricating oil M. Therefore, the gas discharged from the discharge port 113 may also contain the mist-like lubricating oil M sucked into the suction port 114. Even in such a case, the lubricating oil M mixed with the gas can be returned to the oil tank 6 without being discharged to the outside.

[0087] (5) The rotating machine systems 1A and 1B according to a fifth aspect are the rotating machine systems 1A and 1B of (4), wherein the gas discharge pipe 107 has a first straight pipe section 1071 extending linearly from the discharge outlet 113 a predetermined length in a direction connecting an external intake port 112, which draws in the drive gas Gd from the outside in the ejector 110, and the discharge outlet 113.

[0088] As a result, in an area of ​​a predetermined length L2 from the discharge port 113, there is no portion that causes pressure loss for the flow of gas discharged from the discharge port 113 of the ejector 110. Therefore, the performance of the ejector 110 is prevented from being deteriorated. As a result, the gas in the oil distribution pipe 103 can be stably sucked through the suction port 114, and the pressure inside the bearing device 24 can be stably reduced.

[0089] (6) A rotating machine system 1B according to a sixth aspect is a rotating machine system 1B according to (4) or (5), further comprising a temperature sensor 120 capable of detecting the temperature of the lubricating oil M accumulated in the oil reservoir pipe 105 from the outside, and the gas discharge pipe 107B has a second straight pipe section 1072 extending upward in the vertical direction Dv from the position where the lubricating oil M is stored in the oil reservoir pipe 105, and the temperature sensor 120 has a detection unit 121 that extends linearly and is capable of detecting the temperature of the lubricating oil M by contacting its tip with the lubricating oil M, and a temperature visualization unit 122 that is connected to the base end of the detection unit 121 and is arranged outside the gas discharge pipe 107B, and allows the detection result of the detection unit 121 to be visualized, and the detection unit 121 is arranged in a state passing through the second straight pipe section 1072.

[0090] This makes it possible to easily arrange the temperature sensor 120 having the linearly extending detection portion 121. Therefore, the temperature of the lubricating oil M accumulated in the oil reservoir pipe 105 can be detected with a simple configuration.

[0091] (7) A rotating machine system 1A to 1C according to a seventh aspect is any one of the rotating machine systems 1A to 1C of (1) to (6), and includes an electric motor 2 which is the rotating machine 2, a compressor 3 having a compressor rotor 33 which rotates together with the rotor 21 and has a compressor bearing device 32 which rotatably supports the compressor rotor 33, and a transmission 4 arranged between the electric motor 2 and the compressor 3, and the negative pressure units 100A to 100C are connected only to the bearing device 24 of the electric motor 2.

[0092] This allows a drop in the internal pressure to occur only in the bearing device 24, which has a larger clearance than the compressor bearing device 32 and the transmission 4. Therefore, leakage of the lubricating oil M can be suppressed specifically in the bearing device 24, without affecting devices other than the bearing device 24, such as the compressor bearing device 32 and the transmission 4.

[0093] (8) The negative pressure units 100A to 100C according to the eighth aspect are negative pressure units 100A to 100C arranged in the middle of a drain line 8 that sends lubricating oil M supplied to a bearing device 24 of a rotary machine 2 to an oil tank 6, and include an oil inlet portion 101 that can be connected to the drain line 8 and communicates with the bearing device 24, an oil outlet portion 102 that is connected to the drain line 8 and communicates with the oil tank 6, and a passage for the lubricating oil M that connects the oil inlet portion 101 and the oil outlet portion 102. and an ejector 110 having an oil circulation pipe 103 configured as an oil inlet port 114 connected to the oil circulation pipe 103 and extracting gas in the oil circulation pipe 103 through the suction port 114 to reduce the pressure of the oil circulation pipe 103. The oil circulation pipe 103 is located downstream Dfd of the suction port 114 in the flow direction Df of the lubricating oil M and has oil reservoir pipes 105, 105C capable of storing the lubricating oil M below the oil inlet 101 and the oil outlet 102 in the vertical direction Dv.

[0094] By arranging such negative pressure units 100A-100C in the middle of the drain line 8, it is possible to prevent leakage of lubricating oil M from the bearing device 24 while preventing the pressure drop caused by the ejector 110 from extending to other parts other than the target bearing device 24. [Explanation of symbols]

[0095] 1A~1C...Rotating machine system 2...Electric motor (rotating machine) 3. Compressor 4…Gearbox 6. Oil tank 7…Lubricant supply line 8…Drain line 10...Sensor support tube 21...Rotor 22...Rotation axis 23…Output shaft 24...Bearing device 24A…First bearing device 24B…Second bearing device 25…Casing 32...Compressor bearing device 32A…First compressor bearing device 32B…Second compressor bearing device 33...Compressor rotor 41...Transmission input shaft 42...Transmission output shaft 43, 44…Gears 48…Transmission casing 70…Main supply line 71…First supply line 71A…First supply line on one end 71B…Other end side first supply line 72…Second supply line 72A…Second supply line on one end 72B: Second supply line on the other end 73…Third supply line 75…Pump 81…First drain line 81A…First drain line on one end 81B…Other end side first drain line 82…Second drain line 82A…Second drain line on one end 82B…Second drain line on the other end 83…Third drain line 85…Lower drain line 851…Upstream lower drain line 852…Downstream lower drain line 85a...Proximal end 85b…Tip 100A~100C…Negative pressure unit 101...Oil inlet section 102...Oil outlet section 103...Oil flow pipe 1031...Inlet pipe section 1032...Outlet pipe section 104, 104C...Suction pipe 105, 105C...Oil reservoir pipe 1051…Bottom connection 1052…Upstream extension 1053…Downstream extension part 1054…Bend 1055…Bend 1057…Upstream bend 1058…Downstream bend 1059…Discharge port 107, 107B...Gas discharge pipe 1071…First straight pipe section 1072…Second straight pipe section 108...Connecting pipe 110…Ejector 111…Ejector body 111s…Ejector nozzle 112…External intake port 113…Discharge port 114…Suction port 120...Temperature sensor 121…Detection unit 122…Temperature visual inspection part C1…First axis line (axis line) C2…Second axis Da…Axis direction Df…flow direction Dfd: downstream Dfu: upstream Dv: Vertical direction Gd: Drive gas Gm: mixed gas M…Lubricating oil

Claims

1. a rotary machine including: a rotor having a rotary shaft rotatable about an axis; a casing that covers the rotor from the outside in a radial direction centered on the axis; and a bearing device that rotatably supports the rotary shaft relative to the casing; a drain line for recovering lubricating oil supplied to the bearing device; an oil tank that stores the lubricating oil recovered through the drain line; a negative pressure unit that is disposed midway along the drain line and that reduces the pressure inside the bearing device, The negative pressure unit is an oil inlet portion connected to the drain line and communicating with the bearing device; an oil outlet portion connected to the drain line and communicating with the oil tank; an oil circulation pipe connecting the oil inlet and the oil outlet and forming a flow path for the lubricating oil; an ejector having a suction port connected to the oil distribution pipe, and extracting gas from the oil distribution pipe through the suction port to reduce the pressure of the oil distribution pipe; a discharge port through which the supplied drive gas is discharged in the ejector; a gas discharge pipe connected to the oil distribution pipe, the oil distribution pipe is located downstream of the suction port in a flow direction of the lubricating oil and has an oil reservoir pipe that is vertically below the oil inlet and the oil outlet and is capable of storing the lubricating oil, The gas discharge pipe is connected to the oil distribution pipe between the position where the lubricating oil is stored in the oil reservoir pipe and the oil outlet port.

2. The oil sump pipe is a bottom connection portion located below the oil inlet portion and the oil outlet portion in the vertical direction; an upstream extension portion connected to the bottom connection portion at a position close to the oil inlet portion and extending upward in the vertical direction relative to the bottom connection portion; The rotary machine system according to claim 1 , further comprising: a downstream extension portion connected to the bottom connection portion at a position close to the oil outlet portion and extending upward in the vertical direction relative to the bottom connection portion.

3. The oil distribution pipe further includes a suction pipe connecting the suction port and the upstream extension portion, The rotating machine system according to claim 2 , wherein a length from the suction port to the bottom connection portion in the vertical direction is a length that allows an air layer to be formed in the suction pipe.

4. 3. The rotary machine system according to claim 1, wherein the gas discharge pipe has a first straight pipe section that extends linearly from the discharge port by a predetermined length in a direction connecting the discharge port and an external intake port through which the drive gas is drawn from the outside of the ejector.

5. The lubricating oil supply system further includes a temperature sensor capable of detecting the temperature of the lubricating oil accumulated in the oil reservoir pipe from the outside, the gas discharge pipe has a second straight pipe portion extending upward in the vertical direction from a position where the lubricating oil is stored in the oil reservoir pipe, The temperature sensor a detection unit that extends linearly and whose tip comes into contact with the lubricating oil to detect the temperature of the lubricating oil; a temperature visualizing unit connected to a base end of the detecting unit and disposed outside the gas discharge pipe, the temperature visualizing unit enabling visualizing the detection result of the detecting unit, The rotating machine system according to claim 1 or 2, wherein the detection unit is disposed in a state of passing through the second straight pipe section.

6. an electric motor which is the rotary machine; a compressor having a compressor rotor that rotates together with the rotor and a compressor bearing device that rotatably supports the compressor rotor; a transmission disposed between the electric motor and the compressor, The rotating machine system according to claim 1 or 2, wherein the negative pressure unit is connected only to the bearing device of the electric motor.

7. A vacuum unit disposed in a drain line that delivers lubricating oil supplied to a bearing device of a rotary machine to an oil tank, an oil inlet portion connectable to the drain line and communicating with the bearing device; an oil outlet portion connectable to the drain line and communicating with the oil tank; an oil circulation pipe connecting the oil inlet and the oil outlet and forming a flow path for the lubricating oil; an ejector having a suction port connected to the oil distribution pipe, and extracting gas from the oil distribution pipe through the suction port to reduce the pressure of the oil distribution pipe; a discharge port through which the supplied drive gas is discharged in the ejector; a gas discharge pipe connected to the oil distribution pipe, the oil distribution pipe is located downstream of the suction port in a flow direction of the lubricating oil and has an oil reservoir pipe that is vertically below the oil inlet and the oil outlet and is capable of storing the lubricating oil, The gas discharge pipe is a negative pressure unit connected to the oil circulation pipe between the position where the lubricating oil is stored in the oil reservoir pipe and the oil outlet portion.

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