Compressor and compressor system

Abstract

This compressor system is provided with a drive machine and a compressor. The compressor is provided with: a rotor; a casing that covers the rotor; and a squeeze film damper that is disposed at an end of the rotor and is capable of indirectly limiting vibration of the rotor through a fluid. The rotor has a center-filled solid structure, and has a plurality of impellers adjacent to each other in the axial direction, and a bolt fixing part having a plurality of bolts for collectively fixing the plurality of impellers arranged in the axial direction. The squeeze film damper is disposed at the end of the rotor that is not connected to another rotary machine in the axial direction.

Description

Compressor and compressor system

[0001] This application claims priority to Japanese Patent Application No. 2023-218112, filed on December 25, 2023, the contents of which are incorporated herein by reference.

[0002] Generally, a centrifugal compressor includes a rotor having multiple impellers and a casing that covers the impellers from the outside and forms a flow path between the rotor and the impellers. In a centrifugal compressor, a fluid supplied from the outside through a flow path formed in the casing is compressed by the rotation of the impellers.

[0003] For example, as described in Patent Document 1, in such a centrifugal compressor, the rotor is formed by stacking multiple impellers in the axial direction. In this centrifugal compressor, the stacked multiple impellers are fixed by large tie bolts, which are shafts arranged to pass through large holes formed in the centers of the impellers.

[0004] US Patent Application Publication No. 2023 / 0193920

[0005] When a rotor rotates at high speed, the peripheral speed of the rotor's outer periphery increases. To support a rotor with such a high peripheral speed, the size of the bearings must be reduced. As a result, the rotor's shaft diameter must be reduced. On the other hand, to increase the impeller peripheral speed by rotating the rotor at high speed, the impeller diameter must be increased. Furthermore, when compressing a fluid in multiple stages, the axial length of the rotor increases in proportion to the impeller size. Furthermore, as the axial length increases, the vibration generated in the rotor increases. However, the reduction in the size of the bearings supporting the rotor makes it difficult to control the large vibration. Therefore, it is desirable to stably suppress the vibration of a rotor rotating at high speed.

[0006] The present disclosure provides a compressor and a compressor system that can stably suppress vibration of a rotor that rotates at high speed.

[0007] A compressor according to the present disclosure includes a rotor rotatable about an axis, a casing that covers the rotor from the outside in a radial direction based on the axis, and a squeeze film damper that is arranged at an end of the rotor and can indirectly suppress vibration of the rotor via a fluid, wherein the rotor has a solid structure that is formed in a disk shape centered on the axis and has a buried center, and includes a plurality of impellers that are adjacent in the axial direction along which the axis extends, and a bolt fixing portion that has a plurality of bolts that fix the plurality of impellers lined up in the axial direction together, and the squeeze film damper is arranged at an end of the rotor in the axial direction that is not connected to another rotating machine.

[0008] A compressor system according to the present disclosure includes the compressor that compresses a working fluid, and a driver that has a drive shaft that rotates about an axis and drives the compressor, wherein the squeeze film damper is disposed at an end of the rotor at a position remote from the driver in the axial direction.

[0009] According to the compressor and compressor system of the present disclosure, vibration of the rotor rotating at high speed can be stably suppressed.

[0010] Fig. 1 is a schematic diagram showing a compressor system according to an embodiment of the present disclosure. Fig. 2 is a cross-sectional view showing a schematic configuration of a compressor according to an embodiment of the present disclosure. Fig. 3 is a cross-sectional view showing a main part of a squeeze film damper according to the present embodiment. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 2, showing a main part of a coupling portion between a rotor and a transmission rotor by a second coupling according to the present embodiment.

[0011] Hereinafter, an embodiment of a compressor system 1 according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to this embodiment.

[0012] (Configuration of Compressor System) Hereinafter, a compressor system 1 according to an embodiment of the present disclosure will be described with reference to Fig. 1 . The compressor system 1 is disposed in, for example, a chemical plant. As shown in Fig. 1 , the compressor system 1 includes a driver 200, a transmission 300, a compressor 100, a first coupling 410, and a second coupling 420. The driver 200, the transmission 300, and the compressor 100 are arranged coaxially via the first coupling 410 and the second coupling 420 such that the central axes of the rotors 3 of the driver 200, the transmission 300, and the compressor 100 coincide with the axis O of the compressor 100.

[0013] In the following, the direction in which the axis O extends is referred to as the axial direction Da. A radial direction based on the axis O is simply referred to as the radial direction Dr. A direction around the rotor 3 centered on the axis O is referred to as the circumferential direction Dc. In the compressor system 1, the side on which the compressor 100 is disposed relative to the transmission 300 is referred to as the first side Da1 in the axial direction Da. In the compressor system 1, the side on which the compressor 100 is disposed relative to the transmission 300 is referred to as the second side Da2 in the axial direction Da. In the radial direction Dr, the side closer to the axis O is referred to as the inner side Dri in the radial direction Dr. In the radial direction Dr, the side away from the axis O is referred to as the outer side Dro in the radial direction Dr.

[0014] The driver 200 is capable of driving the compressor 100. The driver 200 is, for example, a steam turbine that drives the compressor 100 by utilizing steam generated in the processing of a working fluid (fluid), or an electric motor that drives the compressor 100 at a rotational speed based on the magnitude of a voltage applied from the outside. The driver 200 in this embodiment has a drive shaft 210. The drive shaft 210 is capable of rotating about an axis O.

[0015] The transmission 300 uses a plurality of gears to increase or decrease the rotation of the driver 200 and transmits the rotation to the compressor 100. The transmission 300 of this embodiment is, for example, a speed-up gear. The transmission 300 is disposed between the driver 200 and the compressor 100 in the axial direction Da. The transmission 300 has a transmission rotor 310. One end of the transmission rotor 310 is connected to the drive shaft 210 via a first coupling 410. The other end of the transmission rotor 310 is connected to the rotor 3 via a second coupling 420. The transmission rotor 310 is rotatable about an axis O.

[0016] (Configuration of Compressor) The compressor 100 is driven by the rotation of the drive shaft 210 and compresses a working fluid. The compressor 100 is disposed on a first side Da1 in the axial direction Da relative to the transmission 300. The compressor 100 compresses gas as a working fluid. The compressor 100 of this embodiment is a single-shaft multi-stage centrifugal compressor (multi-stage centrifugal compressor) that compresses gases with a molecular weight of 10 or less, such as hydrogen gas. The compressor 100 is driven at a high speed, for example, of 15,000 rpm or more. The power required for the compressor 100 is, for example, 1,000 kW or more. Furthermore, the suction pressure of the compressor 100 is set to 10 barA or more. As shown in FIG. 2 , the compressor 100 includes a casing 2, a rotor 3, a seal unit 8, and a bearing unit 9.

[0017] (Configuration of Casing) The casing 2 covers the rotor 3 from the outer side Dro in the radial direction Dr. The casing 2 of this embodiment has an outer casing 21, a plurality of diaphragms 22, and a plurality of heads 23.

[0018] The external casing 21 has a cylindrical shape centered on a central axis that is aligned with the axis O of the rotor 3. A first side Da1 (one side) in the axial direction Da of the external casing 21 has an opening large enough to allow the bundle 10, described below, to be inserted therethrough. An end plate 211 is formed on a second side Da2 (other side) in the axial direction Da of the external casing 21. The end plate 211 has a plate shape that extends perpendicular to the axial direction Da. An insertion hole 212 is formed in the center of the end plate 211, the insertion hole 212 being large enough to allow the rotor 3 to be inserted therethrough but not large enough to allow the bundle 10 to be inserted therethrough. As a result, the bundle 10 can be inserted into or removed from the casing 2 by moving in the axial direction Da relative to the external casing 21.

[0019] The multiple diaphragms 22 are arranged to cover the rotor 3 from the outside Dro in the radial direction Dr. The multiple diaphragms 22 are arranged inside the outer casing 21. The diaphragms 22 are annular about the axis O. The multiple diaphragms 22 are stacked to form a cylindrical shape extending in the axial direction Da. The outer peripheral surfaces of adjacent diaphragms 22 are fixed to each other by welding or bolts 71. By fixing the multiple diaphragms 22 to each other, a flow path leading to the impeller 30 is formed inside. The multiple diaphragms 22, together with the head 23, the rotor 3, the seal unit 8, and the bearing unit 9, also form a bundle 10. The bundle 10 is housed inside the outer casing 21. In the bundle 10, the rotor 3, the multiple diaphragms 22, the multiple heads 23, the seal unit 8, and the bearing unit 9 are movable together to form a single unit.

[0020] (Configuration of Flow Path) Here, the flow path formed in the casing 2 by the diaphragm 22 will be specifically described in order from the upstream side, which is the first side Da1 in the axial direction Da, to the downstream side, which is the second side Da2 in the axial direction Da. In this embodiment, the diaphragm 22, together with the outer casing 21 and the head 23, forms, in order from the upstream side where gas flows, a suction port 221, a plurality of casing flow paths 222, and a discharge port 223.

[0021] The suction port 221 allows uncompressed gas that has flowed in from the outside of the casing 2 to flow into the inside of the diaphragm 22. The suction port 221 is where gas flows before it flows into the most upstream impeller 30.

[0022] The casing flow path 222 is formed inside the diaphragm 22. The casing flow path 222 supplies gas from the suction port 221 to the most upstream impeller 30, supplies gas discharged from the upstream impeller 30 to the impeller 30 arranged downstream, and sends gas discharged from the most downstream impeller 30 to the discharge port 223.

[0023] The discharge port 223 discharges the gas that has flowed through the inside of the diaphragm 22 and been compressed to the outside of the casing 2. The discharge port 223 discharges the gas that has been exhausted from the most downstream impeller 30 to the outside.

[0024] The pair of heads 23 are annular members and are disposed inside the outer casing 21. The heads 23 are formed to have a size that allows them to close the openings at both ends of the outer casing 21. The heads 23 in this embodiment include a suction-side head 231 that is disposed on a first side Da1 in the axial direction Da relative to the plurality of diaphragms 22, and a discharge-side head 232 that is disposed on a second side Da2 in the axial direction Da relative to the plurality of diaphragms 22.

[0025] The suction side head 231 is disposed closer to the suction port 221 than the discharge side head 232. The suction side head 231 forms the suction port 221 together with the diaphragm 22 disposed closest to the first side Da1 in the axial direction Da. The suction side head 231 is fixed to the integrated diaphragms 22 by bolts 71 or the like. As a result, the suction side head 231 is integrated with the diaphragms 22.

[0026] The discharge side head 232 is disposed closer to the discharge port 223 than the suction side head 231. The discharge side head 232 forms the discharge port 223 together with the diaphragm 22 disposed closest to the second side Da2 in the axial direction Da. The discharge side head 232 is fixed to the integrated diaphragms 22 with bolts 71 or the like. In this way, the discharge side head 232 is integrated with the diaphragms 22.

[0027] (Configuration of the Rotor) The rotor 3 is housed inside the casing 2. The rotor 3 is rotatable about an axis O. The rotor 3 of this embodiment has a plurality of impellers 30, a shaft end member 5, and a bolt fixing portion 70.

[0028] The impeller 30 compresses the gas by rotating, utilizing centrifugal force. The impeller 30 is formed in a disk shape centered on the axis O and has a solid structure with a buried center. Multiple impellers 30 are adjacent to each other in the axial direction Da. Each impeller 30 is a so-called closed impeller equipped with a disk, multiple blades, and a cover. An impeller flow path 301 for circulating gas is formed inside the impeller 30. The impeller 30 has an impeller peripheral speed of 400 m / s or more. For example, four or more impellers 30 are arranged.

[0029] The impeller 30 has a solid structure formed in a disk shape centered on the axis O and having a filled center. The impeller 30 of this embodiment has an impeller shaft portion 41 and an impeller outer circumferential portion 42.

[0030] The impeller shaft 41 is formed with a circular cross section centered on the axis O. The impeller shaft 41 is formed with a length in the axial direction Da that is approximately the same size as one diaphragm 22. The impeller outer periphery 42 extends from the outer edge of the impeller shaft 41 and protrudes from the impeller shaft 41 toward the outside Dro in the radial direction Dr. The impeller outer periphery 42 is formed integrally with the impeller shaft 41 as a single member. An impeller flow path 301 is formed in the impeller outer periphery 42.

[0031] Furthermore, the impeller shaft portion 41 of this embodiment has bolt holes 38. The bolt holes 38 are formed so as to penetrate the impeller shaft portion 41. The bolt holes 38 are formed in the impeller shaft portion 41. A plurality of bolt holes 38 (for example, twelve locations) are formed at intervals in the circumferential direction Dc centered on the axis O. The plurality of bolt holes 38 are arranged at equal intervals in the circumferential direction Dc. Each bolt hole 38 is formed so as to penetrate the impeller shaft portion 41 in the axial direction Da at a position offset to the outside Dro with respect to the axis O in the radial direction Dr. A bolt 71, which will be described later, is inserted into each bolt hole 38.

[0032] (Configuration of Shaft End Member) The shaft end member 5 is connected to each of the impellers 30 arranged at both ends in the axial direction Da with respect to the plurality of impellers 30 arranged in the axial direction Da. The shaft end member 5 of this embodiment includes a first shaft end member 50 and a second shaft end member 60.

[0033] The first shaft end member 50 is disposed on a first side Da1 in the axial direction Da relative to the multiple impellers 30 that are fixed together. The first shaft end member 50 of this embodiment is fixed to the most upstream impeller 30. The first shaft end member 50 is disposed at a position in the axial direction Da that overlaps with the suction-side head 231. The first shaft end member 50 of this embodiment has a first shaft portion 51, a first supported portion 52, and a first expanded diameter portion 53.

[0034] The first shaft portion 51 is formed in a cylindrical shape extending in the axial direction Da around the axis O. When viewed in the axial direction Da, the first shaft portion 51 is formed in a cylindrical shape centered on the axis O and smaller than the impeller shaft portion 41. A thrust collar 511 is formed on the first shaft portion 51. The thrust collar 511 protrudes outward in the radial direction Dr from the first shaft portion 51 so as to form an annular shape. The thrust collar 511 is formed at a position far away from the first supported portion 52 and the first expanded diameter portion 53 toward the first side Da1 in the axial direction Da. The region where the thrust collar 511 is formed is a region supported by a thrust bearing 93 described later. The outer diameter of the thrust collar 511 is, for example, 120 mm or more. The first shaft portion 51 is rotatably supported in the circumferential direction Dc around the axis O by a bearing portion 9 described later.

[0035] The first supported portion 52 is a region supported by a first journal bearing 91, which will be described later. The first supported portion 52 is formed at a position close to the multiple impellers 30 relative to the first shaft portion 51. The first supported portion 52 is connected to an end of the second side Da2 of the first shaft portion 51 in the axial direction Da. The first supported portion 52 is disposed adjacent to the first expanded diameter portion 53 in the axial direction Da. The first supported portion 52 protrudes toward the outer side Dro in the radial direction Dr relative to the first shaft portion 51. The first supported portion 52 extends in the circumferential direction Dc. When viewed from the axial direction Da, the first supported portion 52 is formed in a disk shape such that its diameter expands toward the outer side Dro in the radial direction Dr relative to the first shaft portion 51. The outer diameter of the first supported portion 52 is smaller than the outer diameter of the thrust collar 511. For example, the outer diameter of the region of the first supported portion 52 supported by the first journal bearing 91 is 120 mm or less. The first enlarged diameter portion 53 is formed integrally with the first shaft portion 51 .

[0036] The first expanded diameter portion 53 is formed at a position closer to the multiple impellers 30 than the first supported portion 52. The first expanded diameter portion 53 is connected to an end of the second side Da2 of the first supported portion 52 in the axial direction Da. The first expanded diameter portion 53 is disposed adjacent to the impeller shaft portion 41 of the most upstream impeller 30 in the axial direction Da. The first expanded diameter portion 53 protrudes toward the outer side Dro in the radial direction Dr relative to the first supported portion 52. The first expanded diameter portion 53 is the region of the first shaft end member 50 that protrudes furthest toward the outer side Dro in the radial direction Dr. The first expanded diameter portion 53 extends in the circumferential direction Dc. When viewed from the axial direction Da, the first expanded diameter portion 53 is formed in a disk shape such that its diameter expands toward the outer side Dro in the radial direction Dr relative to the first supported portion 52. The first expanded diameter portion 53 is formed integrally with the first shaft portion 51 and the first supported portion 52 as a single member. The first expanded diameter portion 53 also has a first nut accommodating recess 531 and a first shaft end bolt hole 532 .

[0037] The first nut accommodating recess 531 is formed to be able to accommodate the nut 72. The first nut accommodating recess 531 is recessed from a side surface of the first expanded diameter portion 53 facing the first side Da1 in the axial direction Da toward the second side Da2 in the axial direction Da. A plurality of first nut accommodating recesses 531 are formed at positions overlapping with the bolt holes 38 when viewed from the axial direction Da. When viewed from the axial direction Da, the first nut accommodating recess 531 is formed in a circular shape that is larger than the bolt hole 38 and has the bolt hole 38 as its center.

[0038] The first shaft end bolt hole 532 is formed to penetrate the first expanded diameter portion 53 in the axial direction Da at a position offset to the outer side Dro with respect to the axis O in the radial direction Dr. The first shaft end bolt hole 532 penetrates the first expanded diameter portion 53 from the first nut accommodating recess 531. A plurality of first shaft end bolt holes 532 are formed in the circumferential direction Dc centered on the axis O. When viewed from the axial direction Da, the first shaft end bolt hole 532 is a hole formed in a circular shape that is slightly larger than the outer shape of the bolt 71. When viewed from the axial direction Da, the first shaft end bolt hole 532 in this embodiment is formed to be in the same position and have the same shape as the bolt hole 38.

[0039] The second shaft end member 60 is connectable to the rotor 3 of another rotary machine such as the driver 200 or the transmission 300. The second shaft end member 60 is disposed on the second side Da2 in the axial direction Da with respect to the multiple impellers 30 that are fixed together. The second shaft end member 60 in this embodiment is fixed to the most downstream impeller 30. The second shaft end member 60 is disposed at a position in the axial direction Da that overlaps with the discharge-side head 232. The second shaft end member 60 has a second shaft portion 61 and a balance piston portion 62.

[0040] The second shaft portion 61 is formed in a cylindrical shape extending in the axial direction Da with the axis O as its center. When viewed in the axial direction Da, the second shaft portion 61 is formed in a cylindrical shape that is smaller than the impeller shaft portion 41 and has the axis O as its center. The second shaft portion 61 is supported by a bearing portion 9, which will be described later, so as to be rotatable in the circumferential direction Dc around the axis O.

[0041] The balance piston portion 62 is formed at a position close to the multiple impellers 30 relative to the second shaft portion 61. The balance piston portion 62 is connected to an end of the first side Da1 of the second shaft portion 61 in the axial direction Da. The balance piston portion 62 is arranged on the second side Da2 in the axial direction Da relative to the multiple impellers 30. The balance piston portion 62 is arranged adjacent to the impeller shaft portion 41 in the axial direction Da. The balance piston portion 62 is arranged at a position in the axial direction Da where it overlaps with the discharge-side head 232. The balance piston portion 62 protrudes from the second shaft portion 61 to the outer side Dro in the radial direction Dr. The balance piston portion 62 extends in the circumferential direction Dc. When viewed from the axial direction Da, the balance piston portion 62 is formed in a disk shape that expands in diameter toward the outer side Dro in the radial direction Dr relative to the second shaft portion 61 and the impeller shaft portion 41. The balance piston portion 62 is formed integrally with the second shaft portion 61 as a single member. The balance piston portion 62 is disposed facing a space in which the working fluid discharged from the most downstream impeller 30 is located, and a space in which the working fluid supplied to the most upstream impeller 30 is located. As a result, a thrust force is generated in the balance piston portion 62 from the first side Da1 to the second side Da2 in the axial direction Da. The balance piston portion 62 also has a second nut accommodating recess 621 and a second shaft-end bolt hole 622.

[0042] The second nut accommodating recess 621 is formed to be able to accommodate the nut 72. The second nut accommodating recess 621 is recessed from a side surface of the balance piston portion 62 facing the second side Da2 in the axial direction Da toward the first side Da1 in the axial direction Da. A plurality of second nut accommodating recesses 621 are formed at positions that overlap with the bolt holes 38 when viewed from the axial direction Da. When viewed from the axial direction Da, the second nut accommodating recess 621 is formed in a circular shape that is larger than the bolt hole 38 and has the bolt hole 38 as its center.

[0043] The second shaft end bolt hole 622 is formed to penetrate the balance piston portion 62 in the axial direction Da at a position offset to the outer side Dro with respect to the axis O in the radial direction Dr. The second shaft end bolt hole 622 penetrates the balance piston portion 62 from the second nut accommodating recess 621. A plurality of second shaft end bolt holes 622 are formed in the circumferential direction Dc centered on the axis O. When viewed from the axial direction Da, the second shaft end bolt hole 622 is a hole formed in a circular shape that is slightly larger than the outer shape of the bolt 71. When viewed from the axial direction Da, the second shaft end bolt hole 622 in this embodiment is formed to be in the same position and with the same shape as the bolt hole 38.

[0044] (Configuration of Bolt Fixing Portion) The bolt fixing portion 70 collectively fixes the plurality of impellers 30 and the shaft end members 5 that are aligned in the axial direction Da. The bolt fixing portion 70 has a plurality of bolts 71 and a pair of nuts 72.

[0045] The multiple bolts 71 are inserted into the bolt holes 38 formed in the multiple impellers 30, respectively. Like a stud bolt, each bolt 71 has no head and is composed only of a threaded portion. Each bolt 71 has a length in the axial direction Da such that, when inserted into the bolt hole 38, its end reaches the first nut accommodating recess 531 and the second nut accommodating recess 621. In other words, the end of the bolt 71 on the first side Da1 in the axial direction Da is arranged to reach the first nut accommodating recess 531. The end of the bolt 71 on the second side Da2 in the axial direction Da is arranged to reach the second nut accommodating recess 621. The multiple bolts 71 are preferably arranged on the impeller shaft portions 41 of the multiple impellers 30, as far inward as possible in the radial direction Dr.

[0046] A pair of nuts 72 is fastened to both ends of each of the multiple bolts 71. The nuts 72 are fastened to the ends of the bolts 71 on a first side Da1 in the axial direction Da within the first nut accommodating recess 531. Another nut 72 is fastened to the ends of the bolts 71 on a second side Da2 in the axial direction Da within the second nut accommodating recess 621. This fixes the multiple impellers 30 together so that they cannot move relative to each other.

[0047] (Configuration of Seal Portion) The seal portion 8 provides a seal between the rotor 3 and the casing 2. The seal portion 8 of this embodiment has a first seal portion 8A, a second seal portion 8B, and a third seal portion 8C.

[0048] The first seal 8A provides a seal between the suction side head 231 and the first shaft 51. The first seal 8A is a dry gas seal. The first seal 8A is detachable from the suction side head 231 and the first shaft 51.

[0049] The second seal portion 8B provides a seal between the discharge side head 232 and the second shaft portion 61. The second seal portion 8B is a dry gas seal. The second seal portion 8B is detachable from the discharge side head 232 and the second shaft portion 61.

[0050] The third seal portion 8C provides a seal between the discharge-side head 232 and the balance piston portion 62. The third seal portion 8C is a labyrinth seal. The third seal portion 8C is disposed at a position spaced apart from the second seal portion 8B on the first side Da1 in the axial direction Da. The third seal portion 8C is fixed to the discharge-side head 232.

[0051] (Configuration of Bearing Unit) The bearing unit 9 supports the rotor 3 rotatably around the axis O relative to the casing 2. The bearing unit 9 rotatably supports only the first shaft end member 50 and the second shaft end member 60. That is, in the rotor 3, the bearing unit 9 does not overlap with the multiple impellers 30 in the axial direction Da, but overlaps only with the first shaft end member 50 and the second shaft end member 60. The bearing unit 9 in this embodiment has a first journal bearing 91, a second journal bearing 92, and a thrust bearing 93.

[0052] The first journal bearing 91 rotatably supports the first supported portion 52. The first journal bearing 91 receives a load in the radial direction Dr that acts on an end of the rotor 3 on the first side Da1 in the axial direction Da. The first journal bearing 91 is disposed in a position in the axial direction Da where it overlaps with the first supported portion 52. The first journal bearing 91 is disposed in a position in the axial direction Da that is closer to the first expanded diameter portion 53 than the thrust collar 511.

[0053] The second journal bearing 92 rotatably supports the second shaft portion 61. The second journal bearing 92 receives a load in the radial direction Dr acting on an end of the rotor 3 on the second side Da2 in the axial direction Da. The second journal bearing 92 is attached inside a cylindrical bearing holder 95. The second journal bearing 92 is disposed at a position overlapping with the second shaft portion 61 in the axial direction Da.

[0054] The thrust bearing 93 rotatably supports the thrust collar 511 of the first shaft portion 51. The thrust bearing 93 receives a load in the axial direction Da acting on the rotor 3. The thrust bearing 93 is attached to the inside of a box-shaped bearing cover 96 together with the first journal bearing 91. The thrust bearing 93 is disposed at a position overlapping with the thrust collar 511 in the axial direction Da.

[0055] (Configuration of Squeeze Film Damper) The squeeze film damper 350 is capable of indirectly suppressing vibration of the rotor 3 via a fluid. The squeeze film damper 350 is disposed at an end of the rotor 3. The squeeze film damper 350 is disposed at an end of the rotor 3 that is not connected to other rotating machines, including the driver 200 and the transmission 300. The squeeze film damper 350 is disposed at an end of the rotor 3 that is far from the driver 200 in the axial direction Da. In other words, the squeeze film damper 350 is disposed at an end of the rotor 3 on the first side Da1 in the axial direction Da that is not connected to the transmission rotor 310. In other words, the squeeze film damper 350 supports the end of the first shaft portion 51 in the axial direction Da. The squeeze film damper 350 is disposed on the opposite side of the thrust bearing 93 from the first journal bearing 91 in the axial direction Da.

[0056] The squeeze film damper 350 is a damper that damps vibrations by supplying oil from the outside between the outer circumferential surface of the end of the rotor 3 and the oil flowing and compressing, thereby generating resistance to vibrations of the rotor 3. As shown in FIG. 3 , the squeeze film damper 350 of this embodiment has an inner member 351, a seal member 352, and a cover member 353.

[0057] The inner member 351 supports the rotor 3. The inner member 351 supports the first shaft portion 51 at a position on the second-most side Da2 with respect to the rotor 3 in the axial direction Da. The inner member 351 is an annular or cylindrical member centered on the axis O. An oil supply hole 351a is formed in the inner member 351, penetrating in the radial direction Dr. The oil supply hole 351a supplies oil supplied from the outside to the outer peripheral surface of the first shaft portion 51. The inner member 351 is fixed to the bearing cover 96.

[0058] The seal member 352 provides a seal between the inner member 351 and the bearing cover 96. The seal member 352 is an annular O-ring centered on the axis O. A pair of seal members 352 are arranged spaced apart in the axial direction Da, sandwiching the oil supply hole 351 a.

[0059] The cover member 353 covers the end of the rotor 3 and the inner member 351. The cover member 353 is detachable from the bearing cover 96. By attaching the cover member 353 to the bearing cover 96, the cover member 353 covers the end face of the rotor 3 from the first side Da1 in the axial direction Da.

[0060] 1, the first coupling 410 connects the transmission 300 and the driving machine 200. The first coupling 410 connects an end of the transmission rotor 310 and an end of the drive shaft 210.

[0061] (Configuration of Second Coupling) The second coupling (coupling) 420 connects the transmission 300 and the compressor 100. The second coupling 420 connects an end of the transmission rotor 310 on a first side Da1 in the axial direction Da and an end of the rotor 3 on a second side Da2 in the axial direction Da. As shown in Fig. 4 , the second coupling 420 has a transmission-side coupling member 421 and a compressor-side coupling member 422.

[0062] The transmission-side coupling member 421 is fixed to an end of the transmission rotor 310 on the first side Da1 in the axial direction Da. The transmission-side coupling member 421 is fixed to the transmission rotor 310 by hydraulic fitting, shrink fitting, or the like.

[0063] The compressor-side coupling member 422 is fixed to an end of the rotor 3 on the second side Da2 in the axial direction Da. The compressor-side coupling member 422 is connected to the rotor 3 using a spline structure. The compressor-side coupling member 422 is fixed to the second shaft portion 61. That is, the second shaft portion 61, which has external teeth, is connected to the compressor-side coupling member 422, which has internal teeth, by meshing with each other. Furthermore, the distance between the end of the transmission rotor 310 and the end of the rotor 3 in the axial direction Da is 400 mm or less. That is, the end face of the second shaft portion 61 is located on the first side Da1 in the axial direction Da relative to the end face of the transmission rotor 310, at a narrow distance of 400 mm or less.

[0064] (Operation and Effect) In the compressor 100 of the compressor system 1 configured as described above, in order to increase the pressure of a light gas with a small molecular weight, such as hydrogen gas, the rotor 3 must be rotated at a high speed of 15,000 rpm or more. When the rotor 3 is rotated at a high speed of 15,000 rpm or more, the peripheral speed of the impeller 30 becomes 400 m / s or more. In order to increase the peripheral speed of the impeller 30, the diameter of the impeller 30 must be increased. Increasing the diameter of the impeller 30 increases the axial length of the rotor 3 in proportion to the size of the impeller 30. Furthermore, when a rotor 3 with a long axial length is rotated at high speed, the vibration generated in the rotor 3 increases.

[0065] Furthermore, the diameter of the area supported by the first journal bearing 91 is set to 120 mm or less. In other words, the size of the first journal bearing 91 that supports the rotor 3 is small. Such a small first journal bearing 91 cannot sufficiently suppress vibrations of the rotor 3 that is rotating at a high speed of 15,000 rpm or more.

[0066] Furthermore, because the rotor 3 is configured by fixing a plurality of solid impellers 30 in a row, the thrust force generated in the thrust bearing 93 increases. Therefore, it is necessary to increase the size of the thrust collar 511. In this embodiment, the diameter of the thrust collar 511, which is the area supported by the thrust bearing 93, is larger than the diameter of the area supported by the first journal bearing 91, which is 120 mm. Therefore, the weight of the first shaft portion 51 on which the thrust collar 511 is formed increases, which increases the vibration of the end of the first shaft portion 51 and the vibration of the rotor 3 as a whole.

[0067] As described above, vibrations of the rotor 3 rotating at high speeds increase due to various factors. To address this issue, a squeeze film damper 350 is disposed at the end of the rotor 3, on which multiple solid impellers 30 are fixed in a row, at a position far from the driver 200 in the axial direction Da. In other words, the squeeze film damper 350 suppresses vibrations at the end of the first shaft portion 51, which is not connected to other rotating machinery. In particular, the squeeze film damper 350 suppresses vibrations at the end of the first shaft portion 51 using oil without direct contact, thereby enabling highly accurate reduction of the destabilizing force generated at the end of the first shaft portion 51, regardless of the type of bearing 9. This allows stable suppression of vibrations of the rotor 3 rotating at high speeds.

[0068] The squeeze film damper 350 is disposed on the opposite side of the thrust bearing 93 from the first journal bearing 91 in the axial direction Da. The region of the rotor 3 opposite the first journal bearing 91 from the thrust bearing 93 is a free end. Specifically, the end of the first shaft portion 51, which is a region on the first side Da1 in the axial direction Da from the region supported by the first journal bearing 91 and the thrust bearing 93, is a free end that is not connected to other machinery, such as the transmission 300. Therefore, this region of the rotor 3 is subject to particularly large vibrations. By disposing the squeeze film damper 350 in this region, vibration of the rotor 3 can be suppressed at a position where vibration is greatest. This allows the squeeze film damper 350 alone to effectively suppress vibration of the rotor 3 rotating at high speed.

[0069] Furthermore, the impeller 30 has a solid structure. In other words, the impeller 30 is not fixed to the outer circumferential surface of the shaft by shrink fitting or the like. Therefore, a large hole for inserting the shaft is not formed in the center of the impeller 30. Because there is no large hole in the impeller 30, the strength of the impeller 30 against the load generated by centrifugal force when the rotor 3 is rotated can be greatly improved.

[0070] Furthermore, a balance piston portion 62 is disposed on the second side Da2 in the axial direction Da relative to the multiple impellers 30. Therefore, the balance piston can reduce the thrust force acting on the rotor 3 from the second side Da2 to the first side Da1 in the axial direction Da. This allows the size of the thrust collar 511 to be reduced. Therefore, the weight of the first shaft portion 51 on which the thrust collar 511 is formed is reduced, making it possible to suppress vibration at the end of the first shaft portion 51. This allows vibration of the rotor 3, which rotates at high speed, to be suppressed at the end of the first shaft portion 51.

[0071] Furthermore, the compressor-side coupling member 422 of the second coupling 420 is connected to the second shaft portion 61 via a spline structure. Because the compressor-side coupling member 422 is connected via a spline structure without using hydraulic pressure, friction, or the like, the compressor-side coupling member 422 and the second shaft portion 61 are connected in a state of physical contact in the circumferential direction Dc. Therefore, even when the required power is very high, such as 1,000 kW or more, and the rotation speed is 15,000 rpm or more, a stable connection can be ensured between the small-diameter second shaft portion 61 and the compressor-side coupling member 422. Furthermore, by connecting the second shaft portion 61 and the compressor-side coupling member 422 in a state of physical contact in the circumferential direction Dc, a stable connection can be ensured with the compressor-side coupling member 422 even if the compressor-side coupling member 422 is made lighter.

[0072] Furthermore, the end face of the second shaft portion 61 in the axial direction Da is located on the first side Da1 in the axial direction Da relative to the end face of the transmission rotor 310, at a narrow distance of 400 mm or less. This axial end distance of 400 mm or less is below the API standard established for attaching and detaching the compressor-side coupling member 422 to the rotor 3. By narrowing the axial end distance between the rotor 3 and the transmission rotor 310 in this manner, the size of the second coupling 420 can be reduced. This reduces the load acting on the second shaft portion 61, thereby suppressing vibration at the end of the second shaft portion 61. This allows vibration of the rotor 3, which rotates at high speed, to be suppressed at the end of the second shaft portion 61.

[0073] (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 within the scope that does not deviate from the gist of the present disclosure are also included.

[0074] The structure of the rotor 3 is not limited to the above structure as long as it is a structure that can rotate at high speed. That is, the impeller 30, the first shaft end member 50, and the second shaft end member 60 of the rotor 3 may have different structures and shapes.

[0075] Furthermore, the structure of the squeeze film damper 350 is not limited as long as it can indirectly suppress vibration of the rotor 3 via the fluid at the end of the rotor 3 .

[0076] Furthermore, the compressor system 1 is not limited to a structure that necessarily includes the transmission 300. The compressor system 1 may have a structure in which the compressor 100 and the driver 200 are directly connected to each other, for example. In this case, it is preferable that the coupling that connects the compressor 100 and the driver 200 has a structure similar to that of the second coupling 420.

[0077] <Additional Notes> The compressor 100 and the compressor system 1 described in the embodiment can be understood, for example, as follows.

[0078] (1) A compressor 100 according to a first aspect includes a rotor 3 rotatable about an axis O, a casing 2 covering the rotor 3 from an outer side Dro in a radial direction Dr based on the axis O, and a squeeze film damper 350 disposed at an end of the rotor 3 and capable of indirectly suppressing vibration of the rotor 3 via a fluid, wherein the rotor 3 has a solid structure formed in a disk shape centered on the axis O with a filled center, and includes a plurality of impellers 30 adjacent to each other in an axial direction Da along which the axis O extends, and a bolt fixing portion 70 having a plurality of bolts 71 for fixing together the plurality of impellers 30 lined up in the axial direction Da, and the squeeze film damper 350 is disposed at an end of the rotor 3 that is not connected to another rotating machine in the axial direction Da.

[0079] As a result, vibrations at the end of the rotor 3 that is not connected to other rotating machinery are suppressed by the squeeze film damper 350. By using the squeeze film damper 350 to suppress vibrations at the end of the rotor 3 using oil without direct contact, it is possible to reduce the destabilizing force generated at the end of the rotor 3 with high precision, regardless of the type of bearing 9. This makes it possible to stably suppress vibrations of the rotor 3 rotating at high speed.

[0080] (2) A compressor 100 according to a second aspect is the compressor 100 of (1), further including a bearing unit 9 that rotatably supports the rotor 3 relative to the casing 2, wherein the bearing unit 9 includes a first journal bearing 91 and a second journal bearing 92 that are spaced apart in the axial direction Da, and a thrust bearing 93 that is located on the opposite side of the second journal bearing 92 from the first journal bearing 91 in the axial direction Da, and the squeeze film damper 350 is located on the opposite side of the thrust bearing 93 from the first journal bearing 91 in the axial direction Da.

[0081] The area of ​​the rotor 3 opposite the first journal bearing 91 with respect to the thrust bearing 93 is a free end. As a result, this area of ​​the rotor 3 is subject to particularly large vibrations. By disposing the squeeze film damper 350 in this area, vibrations of the rotor 3 can be suppressed at the location where the vibrations are greatest. As a result, vibrations of the rotor 3 rotating at high speed can be effectively suppressed by the squeeze film damper 350 alone.

[0082] (3) A compressor system 1 according to a third aspect includes the compressor 100 of (1) or (2) that compresses a working fluid, and a driver 200 that has a drive shaft 210 that rotates about an axis O and drives the compressor 100, in which the squeeze film damper 350 is disposed at an end of the rotor 3 at a position remote from the driver 200 in the axial direction Da.

[0083] (4) A compressor system 1 according to a third aspect is the compressor system 1 of (3), further comprising: a transmission 300 between the driver 200 and the compressor 100 in the axial direction Da, which changes the rotation of the driver 200 and transmits it to the compressor 100 via a transmission rotor 310; and a coupling which connects the transmission rotor 310 and the rotor 3, and the coupling is connected to the rotor 3 by a spline structure.

[0084] As a result, the coupling is connected by a spline structure without using hydraulic pressure, friction, etc., so that the ends of the coupling and the rotor 3 are connected in a state of physical contact in the circumferential direction Dc, thereby ensuring a stable connection between the rotor 3 and the coupling.

[0085] According to the compressor and compressor system of the present disclosure, vibration of the rotor rotating at high speed can be stably suppressed.

[0086] DESCRIPTION OF SYMBOLS 1 Compressor system O Axis 200 Driver 210 Drive shaft 300 Transmission 310 Transmission rotor 100 Compressor 10 Bundle 2 Casing 21 Outer casing 211 End plate 212 Insertion hole 22 Diaphragm 221 Suction port 222 Casing flow path 223 Discharge port 23 Head 231 Suction side head 232 Discharge side head 3 Rotor 30 Impeller 301 Impeller flow path 38 Bolt hole 41 Impeller shaft portion 42 Impeller outer periphery 5 Shaft end member 50 First shaft end member 51 First shaft portion 511 Thrust collar 52 First supported portion 53 First enlarged diameter portion 531 First nut accommodating recess 532 First shaft end bolt hole 60 Second shaft end member DESCRIPTION OF SYMBOLS 61 Second shaft portion 62 Balance piston portion 621 Second nut accommodating recess 622 Second shaft end bolt hole 70 Bolt fixing portion 71 Bolt 72 Nut 8 Seal portion 8A First seal portion 8B Second seal portion 8C Third seal portion 9 Bearing portion 91 First journal bearing 92 Second journal bearing 93 Thrust bearing 95 Bearing holder 96 Bearing cover 350 Squeeze film damper 351 Inner member 351a Oil supply hole 352 Seal member 353 Cover member 410 First coupling 420 Second coupling 421 Transmission side coupling member 422 Compressor side coupling member Da Axial direction Da1 First side Da2 Second side Dc Circumferential direction Dr Radial direction Dri Inner side Dro Outer side

Claims

1. A compressor comprising a rotor rotatable about an axis, a casing covering the rotor from the outer side in the radial direction with respect to the axis, and a squeeze film damper disposed at an end of the rotor and capable of suppressing vibration of the rotor indirectly through a fluid. The rotor is formed in a disk shape centered on the axis and has a solid structure with a filled center, and includes a plurality of impellers adjacent to each other in the axial direction in which the axis extends, and a bolt fixing portion having a plurality of bolts for collectively fixing the plurality of impellers arranged in the axial direction. The squeeze film damper is a compressor disposed at an end of the rotor that is not connected to other rotating machines in the axial direction.

2. The compressor according to claim 1, further comprising a bearing portion that rotatably supports the rotor with respect to the casing. The bearing portion includes a first journal bearing and a second journal bearing disposed apart from each other in the axial direction, and a thrust bearing disposed on the opposite side of the second journal bearing with respect to the first journal bearing in the axial direction. The squeeze film damper is disposed on the opposite side of the first journal bearing with respect to the thrust bearing in the axial direction.

3. A compressor system comprising the compressor according to claim 1 or 2 for compressing a working fluid, and a drive machine having a drive shaft that rotates about an axis and drives the compressor. The squeeze film damper is disposed at an end of the rotor that is far from the drive machine in the axial direction.

4. The compressor system according to claim 3, further comprising a transmission that changes the rotation of the drive machine and transmits the rotation to the compressor through a transmission rotor between the drive machine and the compressor in the axial direction, and a coupling that connects the transmission rotor and the rotor. The coupling is connected to the rotor in a spline structure.

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