Rotary machine

Abstract

To provide a rotary machine capable of preventing heat of high-temperature gas or low-temperature gas from affecting a pinion gear.SOLUTION: A turbo compressor comprises: an operation part for compressing gas; and a transmission mechanism for transmitting power to the operation part. The transmission mechanism comprises a bull gear and a pinion gear 15. The operation part comprises an impeller 10, a casing cover 12 and an intermediate member 19. The pinion gear 15 is formed using chrome molybdenum steel or nickel chrome molybdenum steel. The casing cover 12 is so arranged to form a gap G between itself and an impeller back 10a. The intermediate medium 19 is inserted into a hole part 12a of the casing cover 12 to be interposed between a storage space 13a where the pinion gear 15 is stored in a gear case 13 and the gap G. The intermediate member 19 is formed of a metal material having higher heat resistance than a forming material of the pinion gear 15.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a centrifugal rotary machine. [Background technology]

[0002] Conventionally, a geared type rotary machine in which a gear is arranged in a power transmission path has been known as a centrifugal rotary machine. Patent Document 1 discloses a turbo compressor as an example of a centrifugal rotary machine. In the turbo compressor of Patent Document 1, a first impeller and a second impeller are fixed to a gear shaft portion of a pinion gear. The pinion gear is integrally formed with a rod-shaped gear shaft portion and a gear body portion having teeth.

[0003] The pinion gear disclosed in Patent Document 2 is formed using, for example, chrome molybdenum steel having high rigidity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4876867 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-196327 Summary of the Invention [Problem to be solved by the invention]

[0005] However, pinion gears made of chromium-molybdenum steel or nickel-chromium-molybdenum steel may suffer from reduced durability when exposed to high-temperature gas or low-temperature gas. Therefore, when a rotary machine handles high-temperature gas or low-temperature gas, it is necessary to protect the pinion gear from the heat.

[0006] The present invention has been made in view of the above-mentioned problems, and has as its object to prevent the influence of heat from high-temperature gas or low-temperature gas on a pinion gear. [Means for solving the problem]

[0007] A rotary machine according to one aspect of the present invention includes a working unit and a transmission mechanism, wherein the shaft compresses or expands gas, and the transmission mechanism transmits power to the working unit.

[0008] The transmission mechanism includes a bull gear and a pinion gear, the pinion gear being made of chrome-molybdenum steel or nickel-chrome-molybdenum steel and meshing with the bull gear.

[0009] The actuation unit includes an impeller, a casing cover, and an intermediate member. The casing cover is disposed so as to form a gap between the casing cover and a rear surface of the impeller. The intermediate member is inserted into a hole in the casing cover and is interposed between the gap and an accommodation space in which the pinion gear is accommodated.

[0010] In the rotary machine according to this aspect, the intermediate member is formed of a metal material that has higher heat resistance or cold resistance than chromium-molybdenum steel or nickel-chromium-molybdenum steel.

[0011] In the rotary machine according to the above aspect, by interposing the intermediate member made of the above-described highly heat-resistant or highly cold-resistant metal material between the accommodation space and the gap, the pinion gear accommodated in the accommodation space is prevented from being directly exposed to the high-temperature gas or the low-temperature gas present in the gap, and therefore the rotary machine can prevent the pinion gear from being affected by the heat of the high-temperature gas or the low-temperature gas.

[0012] In the rotary machine according to the above aspect, the intermediate member may be coupled to both the pinion gear and the impeller so as to be capable of transmitting rotation of the pinion gear to the impeller.

[0013] In the rotary machine according to the above aspect, the intermediate member can have a function of transmitting power between the pinion gear and the impeller.

[0014] In the rotary machine according to the above aspect, the intermediate member may include a first intermediate toothing portion and a second intermediate toothing portion. The first intermediate toothing portion may mesh with impeller teeth provided on the impeller at one end surface. The second intermediate toothing portion may mesh with gear teeth provided on the pinion gear at the other end surface. In this case, the intermediate member may be coupled to both the pinion gear and the impeller by the meshing of the first intermediate toothing portion with the impeller teeth portion and the meshing of the second intermediate toothing portion with the gear teeth portion.

[0015] In the rotary machine according to the above aspect, the intermediate member is coupled to the impeller and pinion gear by meshing between the impeller tooth portion and the first intermediate tooth portion and between the gear tooth portion and the second intermediate tooth portion, so that the coupling between the intermediate member and the impeller and the pinion gear can be easily released, for example, during maintenance, etc. Therefore, the rotary machine can ensure high maintainability compared to when the intermediate member is coupled to the impeller and pinion gear by shrink fitting or the like.

[0016] In the rotary machine according to the above aspect, the intermediate member may have a sleeve shape, and the impeller may have an impeller hole formed so that the rotation shaft of the impeller passes through. The rotary machine may further include a tension bolt inserted into the intermediate member hole and the impeller hole of the intermediate member. In this case, a male threaded portion formed on one end of the tension bolt may be fastened to a nut in a state where it protrudes on the side opposite the back surface of the impeller, and another male threaded portion formed on the other end may be fastened to a female threaded portion formed on the pinion gear. The intermediate member may be sandwiched between the impeller and the pinion gear by fastening both male threaded portions of the tension bolt to the nut and the female threaded portion of the pinion gear.

[0017] In the rotary machine according to the above aspect, the intermediate member is clamped between the impeller and the pinion gear by fastening the male threads of the tension bolt to the nut and the female threads. The presence of the intermediate member allows for the use of a correspondingly longer tension bolt. This ensures the tension bolt can stretch to a sufficient extent, thereby more reliably preventing the nut from loosening.

[0018] In the rotary machine according to the above aspect, the impeller may have an impeller hole formed so that the rotation shaft of the impeller passes through. The rotary machine may further include a tension bolt inserted into the impeller hole. In this case, a male thread portion formed on one end of the tension bolt may be fastened to a nut in a state where the male thread portion protrudes on the side opposite the back surface of the impeller, and another male thread portion formed on the other end may be fastened to a female thread portion formed on the intermediate member.

[0019] In the rotary machine according to the above aspect, the intermediate member has a non-sleeve shape without a through hole therein, so that high-temperature gas or low-temperature gas can be prevented from entering the pinion gear side.

[0020] The rotary machine according to the above aspect may further include a seal portion disposed between the intermediate member and an inner circumferential surface of the casing cover that surrounds the hole portion.

[0021] In the rotary machine, a seal portion is provided between the intermediate member and the inner peripheral surface, which is further advantageous in preventing leakage of high-temperature gas or low-temperature gas from the gap into the accommodation space.

[0022] The rotary machine according to the above aspect may further include a vent portion that discharges gas leaking between the intermediate member and an inner circumferential surface of the casing cover that surrounds the hole to the outside.

[0023] In the rotary machine according to the above aspect, since the rotary machine is provided with the vent portion, high-temperature gas or low-temperature gas leaking from the gap between the intermediate member and the inner circumferential surface can be discharged to the outside via the vent portion. Thus, in the rotary machine, the high-temperature gas or low-temperature gas leaking from the gap can be more effectively prevented from flowing into the accommodation space in which the pinion gear is accommodated.

[0024] In the rotary machine according to the above aspect, the working section may be a compression section that compresses gas, and the rotary machine may be used as a centrifugal compressor.

[0025] The rotary machine according to the above aspect is used as a centrifugal compressor, and gas heated by compression is present in the gap. However, by interposing the intermediate member between the accommodation space and the gap, the pinion gear is prevented from being directly exposed to high-temperature gas or low-temperature gas. [Effects of the Invention]

[0026] In the rotary machine according to each of the above aspects, it is possible to prevent the pinion gear from being affected by the heat of the high-temperature gas or the low-temperature gas. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a cross-sectional view showing a partial configuration of a turbo compressor according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing an intermediate member and its surrounding structure in the turbo compressor. [Figure 3] FIG. 6 is a cross-sectional view showing a coupling structure between an intermediate member and an impeller in a turbo compressor according to a second embodiment of the present invention. [Figure 4] FIG. 3 is a cross-sectional view showing a coupling structure between an intermediate member and a pinion gear in the turbo compressor. [Figure 5] FIG. 6 is a cross-sectional view showing a partial configuration of a turbo compressor according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a cross-sectional view showing a partial configuration of a turbo compressor according to a fourth embodiment of the present invention. [Figure 7]FIG. 10 is a cross-sectional view showing a partial configuration of a turbo compressor according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely illustrative of the present invention, and the present invention is not limited to the following embodiments except for the essential configuration.

[0029] [First embodiment] 1. Structure of turbo compressor 1 The structure of a turbo compressor 1 according to a first embodiment of the present invention will be described with reference to Fig. 1. The turbo compressor (centrifugal compressor) 1 according to this embodiment is an example of a rotary machine.

[0030] 1, the turbo compressor 1 includes a working unit 1a that compresses gas and a transmission mechanism 1b that transmits power to the working unit 1a. The working unit 1a includes an impeller 10, a casing 11, a casing cover 12, and an intermediate member 19. The transmission mechanism 1b includes a gear case 13, a bull gear 16, and a pinion gear 15.

[0031] The gear case 13 of the transmission mechanism 1b is a case member having an accommodation space 13a that accommodates the bull gear 16 and the pinion gear 15. A casing cover 12 of the operating part 1a is fastened to the gear case 13 by fastening members (not shown).

[0032] The gear case 13 has a through hole 13b that connects the accommodation space 13a to the outside. The casing cover 12 has a hole portion (through hole) 12a that penetrates in the plate thickness direction and is arranged so that the center line of the hole coincides with the through hole 13b of the gear case 13. The gear case 13 and the casing cover 12 are fastened together so that the through hole 13b of the gear case 13 and the hole portion 12a of the casing cover 12 communicate with each other.

[0033] The casing 11 is attached to the casing cover 12 on the side opposite to the side attached to the gear case 13. The casing 11 is also attached to the casing cover 12 using fastening members (not shown). The impeller 10 is housed in a space (impeller housing space) 1c formed by the casing cover 12 and the casing 11.

[0034] As shown in the enlarged portion of FIG. 1, the casing cover 12 is disposed so as to form a gap G with respect to the back surface (impeller back surface) 10a of the impeller 10 housed in the space 1c.

[0035] In the turbo compressor 1, kinetic energy is imparted to the gas by the rotation of the impeller 10 in the space 1c defined by the casing cover 12 and the casing 11. Then, the gas to which kinetic energy has been imparted is decelerated and pressurized by a diffuser vane (not shown) arranged between the casing cover 12 and the casing 11 (a portion in the space 1c radially outward of the impeller 10).

[0036] The bull gear 16 housed in the housing space 13a of the gear case 13 is connected to a motor or a turbine (not shown). The bull gear 16 receives a rotational driving force from the motor or the turbine and rotates.

[0037] The pinion gear 15 has a gear body 15a having teeth that mesh with the bull gear 16, and a rod-shaped gear shaft 15b formed integrally with the gear body 15a. In this embodiment, the pinion gear 15 is made of chrome-molybdenum steel or nickel-chrome-molybdenum steel, which has high rigidity.

[0038] The gear shaft portion 15b of the pinion gear 15 is disposed so as to pass through the through hole 13b and extend from the accommodation space 13a of the gear case 13 toward the casing cover 12. The gear shaft portion 15b is rotatably supported by a bearing 14 attached to the inner periphery of the gear case 13 that forms the through hole 13b. The impeller 10 rotates by receiving the rotational force of the pinion gear 15.

[0039] The intermediate member 19 is cylindrical and is inserted into a hole (through-hole) 12a formed in the casing cover 12. As a result, the intermediate member 19 is positioned between a space on one side (the gear case 13 side) of the casing cover 12 and a space on the other side (the casing 11 side) of the casing cover 12.

[0040] Although detailed illustration is omitted in Fig. 1 etc., the turbo compressor 1 according to this embodiment is a multi-stage compressor having a plurality of working sections 1a, and is configured so that the temperature of the gas increases toward the later stage. In this embodiment, the working section 1a shown in Fig. 1 is the working section 1a on the later stage side.

[0041] 2. Intermediate member 19 and its surrounding structure The intermediate member 19 and its surrounding structure in the turbo compressor 1 will be described with reference to Fig. 2. Note that the gear case 13 is not shown in Fig. 2.

[0042] As shown in Fig. 2, the casing cover 12 is disposed such that a surface 12c facing the space 1c is spaced from the back surface of the impeller 10 (impeller back surface 10a) to form a gap G. The hole 12a of the casing cover 12 is provided so as to communicate with both the accommodation space 13a of the gear case 13 and the gap G. The intermediate member 19 is inserted into the hole 12a and disposed so as to be interposed between the gap G and the accommodation space 13a. This prevents the pinion gear 15 accommodated in the accommodation space 13a from being exposed to the heat of the high-temperature gas or low-temperature gas present in the gap G.

[0043] In this embodiment, the intermediate member 19 is disposed as a member in the power transmission path between the impeller 10 and the pinion gear 15. Specifically, the intermediate member 19 has a cylindrical shape. The intermediate member 19 does not have a through-hole inside in the axial direction. One end face (impeller-side end face) 19a of the intermediate member 19 is connected to the impeller back surface 10a of the impeller 10 so that the axis coincides with the center of rotation of the impeller 10.

[0044] Furthermore, the other end face (gear shaft side end face) 19b of the intermediate member 19 is joined to an end face (intermediate member side end face) 15c of the gear shaft portion 15b of the pinion gear 15 so that the axis of the other end face (gear shaft side end face) 19b coincides with the axis of the gear shaft portion 15b. Note that various joining means may be used to join the intermediate member 19 to the impeller 10 and to join the intermediate member 19 to the gear shaft portion 15b, such as a coupling structure using meshing gears, shrink fitting, or a key.

[0045] The intermediate member 19 and the impeller 10 are fixed together using a tension bolt 17 and a nut 18. Specifically, the tension bolt 17 is arranged to pass through an impeller hole 10b formed to pass through the rotation shaft of the impeller 10. One end and the other end of the tension bolt 17 are each formed with a male thread (one end male thread 17a, the other end male thread 17b).

[0046] The intermediate member 19 has a female thread portion 19c formed on the rotation axis extending inward from the impeller-side end surface 19a. The other-end male thread portion 17b of the tension bolt 17 inserted into the impeller hole 10b from the side opposite the intermediate member 19 is screwed into the female thread portion 19c of the intermediate member 19. At this time, the one-end male thread portion 17a of the tension bolt 17 protrudes from the impeller hole 10b to the side opposite the intermediate member 19. The intermediate member 19 is joined to the impeller 10 by screwing a nut 18 onto the one-end male thread portion 17a of the tension bolt 17 protruding as described above.

[0047] In this way, by connecting the intermediate member 19 and the impeller 10 using the tension bolt 17 and the nut 18, loosening is less likely to occur between the intermediate member 19 and the impeller 10, even when power is transmitted from the pinion gear 15 to the impeller 10 via the intermediate member 19.

[0048] 2, the casing cover 12 has a vent portion 12b which is a gas passage connecting the hole portion 12a with the outside of the casing cover 12. The vent portion 12b discharges gas leaking into the hole portion 12a (the gap between the outer peripheral surface of the intermediate member 19 and the inner peripheral surface surrounding the hole portion 12a) to the outside of the casing cover 12. The casing cover 12 may be provided with a scavenging portion which is a gas passage for supplying a seal gas into the hole portion 12a (the gap between the outer peripheral surface of the intermediate member 19 and the inner peripheral surface surrounding the hole portion 12a).

[0049] A cylindrical seal portion 20 with a labyrinth structure is disposed between the outer peripheral surface of the intermediate member 19 and the inner peripheral surface surrounding the hole 12a in the casing cover 12. The seal portion 20 prevents gas from leaking from the gap G between the surface 12c of the casing cover 12 and the impeller back surface 10a into the accommodation space 13a in which the pinion gear 15 and other components are accommodated. This provides an additional advantage in protecting the pinion gear 15 accommodated in the accommodation space 13a from high-temperature gas or low-temperature gas.

[0050] 3. Materials for the impeller 10, pinion gear 15, and intermediate member 19 In the turbo compressor 1 according to this embodiment, the pinion gear 15 is made of chrome molybdenum steel or nickel chrome molybdenum steel. In contrast, when high-temperature gas is processed, the intermediate member 19 is made of a metal material that has higher heat resistance than the material (chrome molybdenum steel or nickel chrome molybdenum steel) that forms the pinion gear 15.

[0051] Specifically, the intermediate member 19 is formed using a metal material that has a higher heat resistance than the tempering temperature of the material forming the pinion gear 15. In this embodiment, the intermediate member 19 is formed using austenitic stainless steel, precipitation hardened stainless steel, or titanium alloy.

[0052] On the other hand, when low-temperature gas, specifically gas at or below -100°C, is processed, the intermediate member 19 is made of a metal material that has higher cold resistance than the material (chrome molybdenum steel or nickel chrome molybdenum steel) that forms the pinion gear 15. In this embodiment, the intermediate member 19 is made of austenitic stainless steel, aluminum alloy, nickel chrome alloy, or titanium alloy.

[0053] The impeller 10, like the intermediate member 19, is made of a metal material that has higher heat resistance than the material from which the pinion gear 15 is made.

[0054] 4.Effects In the turbo compressor 1 according to this embodiment, an intermediate member 19 made of a metal material with higher heat resistance than the material from which the pinion gear 15 is made is interposed between the gap G and the accommodation space 13a, thereby preventing the pinion gear 15 accommodated in the accommodation space 13a from being exposed to the heat of the high-temperature gas or low-temperature gas present in the gap G. Therefore, in the turbo compressor 1, the pinion gear 15 can be prevented from being affected by the heat of the high-temperature gas or low-temperature gas.

[0055] Furthermore, in the turbo compressor 1 according to this embodiment, an intermediate member 19 is interposed as a component in the power transmission path between the pinion gear 15 and the impeller 10, and the presence of the intermediate member 19 can prevent the influence of heat from the high-temperature gas or low-temperature gas on the pinion gear 15 through the gap G.

[0056] Furthermore, in the turbo compressor 1 according to this embodiment, the intermediate member 19 does not have a through hole therein, so high-temperature gas or low-temperature gas can be prevented from passing through the interior of the intermediate member 19 and entering the pinion gear side.

[0057] Furthermore, in the turbo compressor 1 according to this embodiment, a seal portion 20 is provided between the outer peripheral surface of the intermediate member 19 and the inner peripheral surface surrounding the hole portion 12a in the casing cover 12, which is even more advantageous in preventing leakage of high-temperature gas or low-temperature gas from the gap G between the surface 12c of the casing cover 12 and the impeller back surface 10a into the accommodation space 13a of the gear case 13.

[0058] Furthermore, in the turbo compressor 1 according to this embodiment, the casing cover 12 is provided with the vent portion 12b, so even if high-temperature gas or low-temperature gas leaks from the gap G between the casing cover 12 and the impeller back surface 10a to between the outer circumferential surface of the intermediate member 19 and the inner circumferential surface surrounding the hole portion 12a in the casing cover 12, the high-temperature gas or low-temperature gas can be discharged to the outside via the vent portion 12b. Therefore, in the turbo compressor 1, even if high-temperature gas or low-temperature gas leaks from the gap G, the high-temperature gas or low-temperature gas flows into the accommodation space 13a of the gear case 13 in which the pinion gear 15 is accommodated, which is advantageous in preventing the pinion gear 15 accommodated in the accommodation space 13a from being exposed to the high-temperature gas or low-temperature gas.

[0059] Furthermore, in this embodiment, the above structure is adopted in the turbo compressor 1, which is a centrifugal compressor, so that even if high-temperature gas or low-temperature gas leaks from the gap G, the pinion gear 15 is prevented from being directly exposed to the high-temperature gas or low-temperature gas by interposing the intermediate member 19 between the gap G and the accommodation space 13a.

[0060] As described above, in the turbo compressor 1 of this embodiment, the pinion gear 15 can be prevented from being affected by the heat of the high-temperature gas or low-temperature gas.

[0061] [Second embodiment] The configuration of a turbo compressor 1 according to a second embodiment of the present invention will be described with reference to Figures 3 and 4. The turbo compressor 1 according to this embodiment has the same configuration as the turbo compressor 1 according to the first embodiment, except for the configuration described below.

[0062] 3, impeller teeth 10c are formed around the openings of impeller holes 10b on impeller back surface 10a of impeller 10. Impeller teeth 10c are portions having gear-shaped projections and recesses.

[0063] A first intermediate tooth portion 19d is formed around the opening of the female thread portion 19c on the impeller side end surface 19a of the intermediate member 19. The first intermediate tooth portion 19d is a portion having gear-shaped projections and recesses formed to mesh with the impeller tooth portion 10c.

[0064] 4, a gear tooth portion 15d is formed around the rotation axis on an end face (intermediate member side end face) 15c of the gear shaft portion 15b of the pinion gear 15 on the intermediate member 19 side. The gear tooth portion 15d is a portion having gear-shaped concaves and convexes.

[0065] A second intermediate toothed portion 19e is formed around the rotation shaft on a gear shaft side end face 19b opposite to the impeller side end face 19a of the intermediate member 19. The second intermediate toothed portion 19e is a member having gear-shaped projections and recesses formed to mesh with the gear toothed portion 15d.

[0066] The turbo compressor 1 according to this embodiment has the same structure as the turbo compressor 1 according to the first embodiment, except for the connection structure between the intermediate member 19, the impeller 10, and the gear shaft portion 15b, and therefore can obtain the same effects as the turbo compressor 1 according to the first embodiment.

[0067] Furthermore, in the turbo compressor 1 according to this embodiment, the intermediate member 19, the impeller 10, and the pinion gear 15 are coupled (coupled using a so-called tooth structure) by the meshing of the impeller tooth portion 10c with the first intermediate tooth portion 19d and the meshing of the gear tooth portion 15d with the second intermediate tooth portion 19e, so that the coupling between the intermediate member 19, the impeller 10, and the pinion gear 15 can be easily released, for example, during maintenance. Therefore, the turbo compressor 1 can ensure high maintainability compared to when the intermediate member 19, the impeller 10, and the pinion gear 15 are coupled by shrink fitting or the like.

[0068] Although not shown in Figures 3 and 4, in this embodiment in which the intermediate member 19 is connected to the impeller 10 and the gear shaft portion 15b using a double tooth structure, it is also possible to clamp the intermediate member 19 between the impeller 10 and the pinion gear 15 using a tension bolt 17.

[0069] [Third embodiment] The configuration of a turbo compressor 1 according to a third embodiment of the present invention will be described with reference to Fig. 5. The turbo compressor 1 according to this embodiment has the same configuration as the turbo compressor 1 according to the first embodiment, except for the configuration described below.

[0070] 5, in the turbo compressor 1 according to this embodiment, the gear shaft portion 15b of the pinion gear 15 and the intermediate member 19 are joined by shrink fitting. Specifically, a shrink-fit recess 19f is formed in the gear shaft side end surface 19b of the intermediate member 19, with the rotation axis as the center.

[0071] A shrink-fit protrusion 15e is provided on an intermediate member side end surface 15c of the gear shaft portion 15b of the pinion gear 15, centered on the rotation axis, and protrudes toward the intermediate member 19. The shrink-fit protrusion 15e of the gear shaft portion 15b is fitted into a shrink-fit recess 19f of the intermediate member 19, the diameter of which has been increased by increasing the temperature, and is tightly fastened to the shrink-fit recess 19f by decreasing the temperature of the intermediate member 19.

[0072] The turbo compressor 1 according to this embodiment has the same structure as the turbo compressors 1 according to the first and second embodiments, except for the connection structure between the intermediate member 19 and the gear shaft portion 15b, and therefore can obtain the same effects as those of the first and second embodiments.

[0073] As for the method of joining the intermediate member 19 and the impeller 10, the same method as in the first and second embodiments can be adopted, or a joining method by shrink fitting can also be adopted.

[0074] It is also possible to provide a shrink-fit recess on the intermediate member-side end surface 15c of the gear shaft portion 15b, provide a shrink-fit protrusion on the gear shaft-side end surface 19b of the intermediate member 19, and join them by shrink-fitting. In this case, however, the temperature of the gear shaft portion 15b is raised to expand the diameter of the shrink-fit recess. In this embodiment, too, the intermediate member 19 is formed of a metal material that is more heat-resistant than the pinion gear 15 including the gear shaft portion 15b. Therefore, from the viewpoint of suppressing a decrease in durability of the pinion gear 15, it is desirable to provide a shrink-fit recess 19f in the intermediate member 19 and a shrink-fit protrusion 15e on the gear shaft portion 15b, as in this embodiment.

[0075] [Fourth embodiment] The configuration of a turbo compressor 1 according to a fourth embodiment of the present invention will be described with reference to Fig. 6. The turbo compressor 1 according to this embodiment has the same configuration as the turbo compressor 1 according to the first embodiment, except for the configuration described below. Also, the gear case 13 is not shown in Fig. 6.

[0076] As shown in FIG. 6, in the turbo compressor 1 according to this embodiment, the intermediate member 19 is also inserted into a hole 12a formed in the casing cover 12 and is interposed between the gap G (the gap between the casing cover 12 and the impeller back surface 10a) and the accommodation space 13a.

[0077] In this embodiment, the intermediate member 19 has a sleeve shape. An intermediate member hole 19g is formed in the center of the intermediate member 19, penetrating in the axial direction between an impeller-side end face 19a and a gear-shaft-side end face 19b. The intermediate member hole 19g is continuous with the impeller hole 10b on the impeller 10 side.

[0078] The gear shaft portion 15b of the pinion gear 15 has a female screw portion 15f formed on the rotation axis from the intermediate member side end face 15c. The female screw portion 15f is continuous with an intermediate member hole 19g of the intermediate member 19.

[0079] In the turbo compressor 1 according to this embodiment, the tension bolt 17 is formed to be longer than in the first embodiment. The other-end male thread portion 17b of the tension bolt 17 is inserted so as to pass through the impeller hole 10b and the intermediate member hole 19g from the side opposite the intermediate member 19, and is threadedly engaged with the female thread portion 15f of the gear shaft portion 15b. At this time, the one-end male thread portion 17a of the tension bolt 17 protrudes from the impeller hole 10b to the side opposite the intermediate member 19. A nut 18 is threadedly engaged with the one-end male thread portion 17a of the tension bolt 17 that protrudes. As a result, the intermediate member 19 is sandwiched between the gear shaft portion 15b and the impeller 10 in the power transmission path from the pinion gear 15 to the impeller 10.

[0080] In the turbo compressor 1 according to this embodiment, an intermediate member 19 is sandwiched between the gear shaft portion 15b and the impeller 10 in the power transmission path from the pinion gear 15 to the impeller 10. The presence of the intermediate member 19 allows a longer tension bolt 17 to be used in accordance with the length of the intermediate member 19. This ensures that the tension bolt 17 can stretch to a sufficient extent, and the nut 18 can be more reliably prevented from loosening.

[0081] Although detailed description will be omitted, a tooth structure can be used for the connection between the impeller back surface 10a of the impeller 10 and the impeller-side end face 19a of the intermediate member 19, and for the connection between the gear-shaft-side end face 19b of the intermediate member 19 and the intermediate-member-side end face 15c of the gear shaft portion 15b, as in the second embodiment, or shrink fitting can be used as in the third embodiment. When a tooth structure is used for each connection, excellent maintainability can be achieved while ensuring high connectability between the two, as in the second embodiment.

[0082] Furthermore, the turbo compressor 1 according to this embodiment can also obtain the same effects as those of the first embodiment.

[0083] [Fifth embodiment] The configuration of a turbo compressor 1 according to a fifth embodiment of the present invention will be described with reference to Fig. 7. The turbo compressor 1 according to this embodiment has the same configuration as the turbo compressor 1 according to the first embodiment, except for the configuration described below. Also, the gear case 13 is not shown in Fig. 7.

[0084] As shown in FIG. 7, in the turbo compressor 1 according to this embodiment, the intermediate member 19 is also inserted into a hole 12a formed in the casing cover 12 and is interposed between the gap G and the accommodation space 13a.

[0085] In this embodiment, the gear shaft portion 15b is directly coupled to the impeller 10. The intermediate member 19 is fitted onto the gear shaft portion 15b so that the inner periphery 19h is in close contact with the outer periphery 15g of the gear shaft portion 15b.

[0086] As described above, this embodiment employs a structure in which the gear shaft portion 15b is directly coupled to the impeller 10. For this purpose, a female thread portion 15f is formed on the portion of the gear shaft portion 15b facing the impeller 10. The other end male thread portion 17b of the tension bolt 17, which is inserted into the impeller hole 10b from the side opposite the gear shaft portion 15b, is threadedly engaged with the female thread portion 15f. At this time, one end male thread portion 17a of the tension bolt 17 protrudes from the impeller hole 10b on the side opposite the gear shaft portion 15b. The impeller 10 and the gear shaft portion 15b are coupled together by threading a nut 18 onto the one end male thread portion 17a of the protruding tension bolt 17.

[0087] In this embodiment, the intermediate member 19 is fitted onto the gear shaft portion 15b, and therefore does not function as a member for transmitting power from the pinion gear 15 to the impeller 10.

[0088] Although detailed description will be omitted, a tooth structure can be adopted for the connection between the impeller 10 and the gear shaft portion 15b, as in the second embodiment. In this case, similar to the second embodiment, it is possible to ensure high connection between them while achieving excellent maintainability. Furthermore, a connecting means such as shrink fitting or a key may be used to connect the intermediate member 19 and the impeller 10.

[0089] Furthermore, the turbo compressor 1 according to this embodiment differs from the first embodiment in that an intermediate member 19 is not disposed in the power transmission path from the pinion gear 15 to the impeller 10. However, since the other configurations are the same, it is possible to obtain the same effects as the first embodiment.

[0090] [Variations] In the first to fifth embodiments, the turbo compressor (centrifugal compressor) 1 is used as an example of a rotary machine, but the present invention can also be applied to a centrifugal turbine.

[0091] Furthermore, in the first to fifth embodiments, the turbo compressor 1 is configured to include multiple working sections 1a, with the gas temperature increasing toward the downstream side, and each working section 1a being a downstream working section, but the present invention is not limited to this. For example, the turbo compressor 1 does not have to be a multi-stage compressor, and even in the case of a multi-stage compressor, the configuration of the present invention can be adopted for the working sections 1a on the upstream side.

[0092] In the first to fifth embodiments, the intermediate member 19 is formed using austenitic stainless steel, precipitation hardened stainless steel, or titanium, but the present invention is not limited to these materials for the intermediate member 19. That is, when handling gases with temperatures higher than the tempering temperature of the chromium-molybdenum steel or nickel-chromium-molybdenum steel from which the pinion gear 15 is formed, the intermediate member 19 can be formed using various metal materials that have heat resistance to such temperatures.

[0093] Similarly, when low-temperature gas is used, the intermediate member 19 may be made of various metal materials having higher cold resistance than chromium-molybdenum steel or nickel-chromium-molybdenum steel.

[0094] In the second embodiment described above, a tooth structure is adopted for both the connection between the pinion gear 15 and the intermediate member 19 and the connection between the intermediate member 19 and the impeller 10, but in the present invention, a tooth structure can also be adopted for only one of the connections.

[0095] In the third embodiment, the pinion gear 15 and the intermediate member 19 are joined by shrink fitting, but the intermediate member 19 and the impeller 10 can also be joined by shrink fitting. Furthermore, when a sleeve-shaped intermediate member 19 is used as in the fifth embodiment, the pinion gear 15 and the impeller 10 can also be joined by shrink fitting.

[0096] In the above-described fifth embodiment, the intermediate member 19 may come into contact with the impeller 10. In this case, meshing teeth may be provided on the end of the intermediate member 19 on the impeller side 10 and on the back surface of the impeller 10, so that power may be transmitted to the impeller 10 via the intermediate member 19. The gear shaft portion 15b does not necessarily have to be directly connected to the impeller 10.

[0097] In the first to fifth embodiments, the casing 11 and the casing cover 12 may be integrally formed. Also, although the seal portion 20 is provided in the hole 12a of the casing cover 12, providing the seal portion 20 is not essential in the present invention.

[0098] In the first to fifth embodiments, the casing cover 12 is provided with the vent portion 12b penetrating from the hole portion 12a to the outside, but in the present invention, it is not essential to provide the vent portion 12b on the casing cover 12. There is no particular limit to the number of vent portions 12b provided on the casing cover 12, and it may be one or more.

[0099] In the first, second, fourth, and fifth embodiments, tension bolts 17 are used to secure the components together more firmly, but the present invention does not require the use of tension bolts 17. Other configurations (such as a coupling) may also be employed to prevent the connected portions from coming apart when the pinion gear 15 and the impeller 10 rotate. [Explanation of symbols]

[0100] 1. Turbo compressor (rotating machine) 10 impeller 10a Impeller back 11 Casing 12 Casing cover 12a Hole (through hole) 13 Gear case 13a Containment Space 15 Pinion gear 15b Gear shaft 17 Tension bolt 18 Nut 19 Intermediate parts 20 Seal part G Gap

Claims

1. A rotating machine, a working part that compresses or expands gas; a transmission mechanism that transmits power to the operating unit; Equipped with The transmission mechanism is Brugia and a pinion gear formed using chrome molybdenum steel or nickel chrome molybdenum steel and meshing with the bull gear; Equipped with The actuation unit is The impeller and a casing cover disposed so as to form a gap between the casing cover and a back surface of the impeller; an intermediate member that is inserted into a hole in the casing cover and is interposed between the gap and an accommodation space in which the pinion gear is accommodated; Equipped with the intermediate member is formed of a metal material having higher heat resistance or cold resistance than chromium-molybdenum steel or nickel-chromium-molybdenum steel; Rotating machinery.

2. the intermediate member is coupled to both the pinion gear and the impeller so as to be capable of transmitting rotation of the pinion gear to the impeller; The rotary machine according to claim 1 .

3. The intermediate member is a first intermediate tooth portion that meshes with an impeller tooth portion provided on the impeller at one end surface; a second intermediate tooth portion that meshes with a gear tooth portion provided on the pinion gear at the other end surface, the intermediate member is coupled to both the pinion gear and the impeller by meshing of the first intermediate toothing portion with the impeller toothing portion and meshing of the second intermediate toothing portion with the gear toothing portion; The rotary machine according to claim 2 .

4. the intermediate member has a sleeve shape, the impeller has an impeller hole formed so that a rotation shaft of the impeller passes through it, a tension bolt inserted into an intermediate member hole of the intermediate member and the impeller hole, A male thread portion formed on one end of the tension bolt is fastened to a nut in a state where the male thread portion protrudes on the opposite side of the back surface of the impeller, and another male thread portion formed on the other end is fastened to a female thread portion formed on the pinion gear, the intermediate member is sandwiched between the impeller and the pinion gear by fastening the two male threaded portions of the tension bolt to the nut and the female threaded portion of the pinion gear. The rotary machine according to claim 3 .

5. the impeller has an impeller hole formed so that a rotation shaft of the impeller passes through it, Further provided is a tension bolt inserted into the impeller hole, A male threaded portion formed on one end of the tension bolt is fastened to a nut in a state where the male threaded portion protrudes on the opposite side of the back surface of the impeller, and another male threaded portion formed on the other end of the tension bolt is fastened to a female threaded portion formed on the intermediate member. The rotary machine according to claim 2 .

6. a seal portion disposed between the intermediate member and an inner circumferential surface of the casing cover surrounding the hole portion, 6. A rotary machine according to claim 1.

7. a vent portion for discharging gas leaked between the intermediate member and an inner circumferential surface of the casing cover surrounding the hole portion to the outside, 6. A rotary machine according to claim 1.

8. The working unit is a compression unit that compresses gas, and the compressor is used as a centrifugal compressor. A rotary machine according to any one of claims 1 to 5.

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