(19)
(11)EP 3 557 076 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
13.01.2021 Bulletin 2021/02

(21)Application number: 17896781.6

(22)Date of filing:  20.02.2017
(51)International Patent Classification (IPC): 
F04D 29/28(2006.01)
F04D 29/62(2006.01)
F04D 29/26(2006.01)
(86)International application number:
PCT/JP2017/006146
(87)International publication number:
WO 2018/150576 (23.08.2018 Gazette  2018/34)

(54)

IMPELLER, ROTARY MACHINE, METHOD FOR MANUFACTURING IMPELLER, AND METHOD FOR MANUFACTURING ROTARY MACHINE

LAUFRAD, DREHMASCHINE, VERFAHREN ZUR HERSTELLUNG EINES LAUFRADS UND VERFAHREN ZUR HERSTELLUNG EINER DREHMASCHINE

TURBINE, MACHINE ROTATIVE, PROCÉDÉ DE FABRICATION DE TURBINE ET PROCÉDÉ DE FABRICATION DE MACHINE ROTATIVE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(43)Date of publication of application:
23.10.2019 Bulletin 2019/43

(73)Proprietor: Mitsubishi Heavy Industries Compressor Corporation
Minato-ku Tokyo 108-0014 (JP)

(72)Inventors:
  • YAGI Nobuyori
    Tokyo 108-8215 (JP)
  • MORIKAWA Akihiko
    Hiroshima-shi Hiroshima 733-8553 (JP)
  • TOKUYAMA Shinichiro
    Hiroshima-shi Hiroshima 733-8553 (JP)
  • TAKAGI Hiroki
    Hiroshima-shi Hiroshima 733-8553 (JP)
  • ITAGAKI Kenji
    Hiroshima-shi Hiroshima 733-8553 (JP)

(74)Representative: Studio Torta S.p.A. 
Via Viotti, 9
10121 Torino
10121 Torino (IT)


(56)References cited: : 
EP-A1- 3 059 454
JP-A- H11 347 811
JP-A- 2004 336 031
US-A- 2 392 858
JP-A- H06 193 585
JP-A- 2001 009 626
JP-A- 2015 101 967
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Technical Field



    [0001] The present invention relates to an impeller, a rotary machine, a method for manufacturing an impeller, and a method for manufacturing a rotary machine.

    Background Art



    [0002] For example, a rotary machine used in an industrial compressor, a centrifugal chiller, a small-sized gas turbine, and the like, has an impeller having a disk fixed to a rotating body to which a plurality of blades are attached. The rotary machine configured as described above gives pressure energy and velocity energy to a gas by rotating the impeller.

    [0003] As the impeller, a so-called closed impeller, in which a disk and a blade are integrated and a cover is integrally provided with the blade, is known (for example, refer to Japanese Patent No. 5907723, Japanese Unexamined Patent Application, First Publication No. 2013-47479).

    [0004] US-A-2392858 discloses a rotor subject to high centrifugal stresses comprising a disk member having an outer surface forming two axially and radially spaced outer annular shoulders, and a reinforcing ring substantially S-shaped in cross-section with inner and outer end portions forming radially and axially spaced inner surfaces tightly engaging the respective outer shoulders of the disk member to resist radial expansion thereof and an intermediate portion connecting the end portions and having a surface axially facing the disk member and gradually curving away therefrom in the radial direction.

    [0005] EP-A1-3059454 discloses an impeller is equipped with: a disk section that is fixed to a rotary shaft at least at the side of a first end in a direction of the axis and extends outward in a radial direction from the side of a second end; blade sections that are disposed to protrude from the disk section toward the side of the first end; and a cover section that covers the blade sections. The disk section includes a first member and a second member that are divided from each other in the direction of the axis by a dividing plane, which is orthogonal to the axis, at an inner side in the radial direction relative to the blade sections. The first member and the second member are joined on the dividing plane.

    Summary of Invention


    Technical Problem



    [0006] There is a closed impeller combined by bonding a plurality of parts (a disk, a plurality of blades, and a cover) as the closed impeller. In a case of having such a bonded structure, it is difficult to combine the closed impeller such that connection positions of the plurality of parts are desired connection positions. For this reason, it is difficult to make a shape of a flow passage disposed between the disk and the cover a desired shape, and thus there is a possibility that the performance of the impeller decreases.

    [0007] In order to solve such problems, integrating the disk, the plurality of blades, and the cover (making an impeller one piece) is considered. Although work of combining is unnecessary in this case, it is necessary to perform high-precision sharpening processing with the use of a tool with respect to a material to become a base material of the impeller.

    [0008] In a case of making the impeller one piece, a part of the disk is disposed in a middle portion of the donut-shaped cover. Thus, when processing the base material of the impeller with the tool, this part of the disk becomes an obstacle at the time of tool insertion, and thereby there is a possibility that accurately processing the flow passage becomes difficult.

    [0009] The present invention relates to an impeller, a rotary machine, a method for manufacturing an impeller, and a method for manufacturing a rotary machine, in which the accuracy of the shape of a flow passage to be formed between a second disk member and a cover can be enhanced after integrally configuring the second disk member, which is a separate body from a first disk member, a blade, and the cover.

    Solution to Problem



    [0010] The above problem is solved by an impeller, a rotary machine, a method for manufacturing an impeller, and a method for manufacturing a rotary machine according to the appended set of claims.

    [0011]  By making the first disk member and the second disk member, which configure the disk, separate bodies as described above, it becomes easy to insert a tool, which is used when forming the flow passage to be disposed between the cover and the second disk member, into the cover and the second disk member. Therefore, the accuracy of the shape of the flow passage can be enhanced.

    [0012] In addition, by integrating the second disk member, the blade, and the cover, work of combining the second disk member, the blade, and the cover becomes unnecessary. Therefore, a decrease in the accuracy of the shape of the flow passage attributable to assembling work can be limited.

    [0013] Since the first shrink-fitting portion formed through shrink-fitting is included in the boundary portion between the outer circumferential surface of the engaging portion and the inner circumferential surface of the recessed portion as described above, it becomes possible to form the first shrink-fitting portion by heating an outer circumferential surface of a portion of the first disk member, which defines the recessed portion. Accordingly, since it is not necessary to directly heat the second disk member integrated with the blade when forming the first shrink-fitting portion, deformation of the blade attributable to the heating can be limited.

    [0014] Thanks to the claimed configuration, a plurality of outer circumferential surfaces of the engaging portion are provided. In a case where, out of the plurality of outer circumferential surfaces, a width of a certain outer circumferential surface in a central axis direction of the disk is the same as a width of another outer circumferential surface disposed on an outer side of the certain outer circumferential surface in the central axis direction of the disk, the area of another outer circumferential surface disposed on the outer side is wider.

    [0015] Therefore, when a case where a desired area is obtained with the use of an engaging portion having only one outer circumferential surface is compared with a case where this desired area is obtained with the use of an engaging portion having a plurality of outer circumferential surfaces (engaging portion including the plurality of step portions), the engaging portion having the plurality of outer circumferential surfaces can be made to have a smaller length in the central axis direction of the disk than the engaging portion having only one outer circumferential surface.

    [0016] Thanks to the claimed configuration, the occurrence of fretting (in this case, surface damage that occurs when minute reciprocating slide has repeatedly acted on between the first disk member and the second disk main body, which come into contact with each other) can be limited by the gap.

    [0017] Thanks to the claimed configuration, it is possible to cause an anchoring effect in the first shrink-fitting portion (an effect that the engaging portion becomes unlikely to come out from the recessed portion in the central axis direction of the disk). Thus, the strength of connection between the first disk member and the second disk member can be improved.

    [0018] By providing the positioning key in the portion where the first disk main member has abutted against the second disk member in the central axis direction of the disk, positioning between the first disk member and the second disk member (positioning in a rotation direction of which a rotation axis is the central axis of the disk) can be easily performed.

    [0019] Thanks to the claimed configuration, it is possible to provide the second shrink-fitting portion at a position separated away from the first shrink-fitting portion. Thus, the impeller can be fixed to the outer circumferential surface of the rotating body after limiting interference between the first shrink-fitting portion and the second shrink-fitting portion.

    [0020] By making the shrink-fitting proportion of the second shrink-fitting portion formed after the first shrink-fitting portion lower than the shrink-fitting proportion of the first shrink-fitting portion as described above, it can be limited that heat attributable to heating performed when forming the second shrink-fitting portion has an adverse effect on the first shrink-fitting portion.

    [0021] By performing the step of forming the first disk member and the step of integrally forming the second disk member, the blade provided on the second disk member, and the cover that is provided on the blade and covers the blade as separate steps as described above, it becomes possible to easily process the flow passage to be formed between the second disk member and the cover with the use of a tool. Therefore, the accuracy of the shape of the flow passage can be enhanced.

    [0022] By heating the first disk member from the outer circumferential surface side of the first disk member and shrink-fitting the outer circumferential surface of the engaging portion to the inner circumferential surface of the recessed portion, it becomes not necessary to directly heat the second disk member integrated with the blade when forming the first shrink-fitting portion. Thus, deformation of the blade attributable to the heating when forming the first shrink-fitting portion can be limited.

    [0023] Thanks to the claimed configuration, since it becomes not necessary to directly heat the second disk member integrated with the blade by heating the first disk main member from the outer circumferential surface side of the portion of the first disk member, in which recessed portion is not formed, in a state where the rotating body is inserted in the impeller as described above, deformation of the blade attributable to the heating can be limited.

    [0024] By making the heating temperature when forming the second shrink-fitting portion formed after the first shrink-fitting portion lower than the heating temperature when forming the first shrink-fitting portion as described above, it can be limited that heating when forming the second shrink-fitting portion has an adverse effect on the first shrink-fitting portion.

    Advantageous Effects of Invention



    [0025] According to the present invention, the accuracy of the shape of the flow passage of the impeller can be enhanced after integrally configuring the second disk member, which is a separate body from the first disk member, the blade, and the cover.

    Brief Description of Drawings



    [0026] 

    FIG. 1 is a sectional view schematically showing a simplified configuration of a rotary machine according to a first embodiment of the present invention.

    FIG. 2 is a sectional view of an enlarged portion surrounded by a region A, out of structures shown in FIG. 1.

    FIG. 3 is a sectional view of an enlarged portion surrounded by a region B, out of structures shown in FIG. 2.

    FIG. 4 is a sectional view showing disassembled first and second disk members before shrink-fitting.

    FIG. 5 is a sectional view of enlarged main portions of an impeller according to a modification example of the first embodiment of the present invention.

    FIG. 6 is a (first) sectional view showing a method for manufacturing an impeller according to the first embodiment of the present invention.

    FIG. 7 is a (second) sectional view showing the method for manufacturing an impeller according to the first embodiment of the present invention.

    FIG. 8 is a (third) sectional view showing the method for manufacturing an impeller according to the first embodiment of the present invention.

    FIG. 9 is a sectional view of an impeller according to a second embodiment of the present invention.

    FIG. 10 is a sectional view of an enlarged portion of the impeller shown in FIG. 9, which is surrounded by a region C.

    FIG. 11 is a sectional view showing an impeller according to a third embodiment of the present invention.

    FIG. 12 is a sectional view of an enlarged portion surrounded by a region G, out of structures shown in FIG. 11.

    FIG. 13 is a sectional view of enlarged main portions of an impeller according to a modification example of the third embodiment of the present invention.


    Description of Embodiments


    (First Embodiment)



    [0027] FIG. 1 is a sectional view schematically showing a simplified configuration of a rotary machine according to a first embodiment of the present invention. In FIG. 1, A indicates a region (hereinafter, referred to as a "region A"), F indicates a working fluid (hereinafter, referred to as a "working fluid F"), O1 indicates a central axis of a disk 21 (hereinafter, referred to as a "central axis O1"), O2 indicates an axis of a rotating body 11 (hereinafter, referred to as an "axis O2"), and an X-direction indicates a central axis O1 direction of the disk 21. The central axis O1 and the axis O2 extend in the same direction (X-direction) and match each other.

    [0028]  FIG. 1 shows a centrifugal compressor as an example of a rotary machine 10. Since it is difficult to show details of impellers 16 shown in FIG. 2, which are to be described later, FIG. 1 shows the impellers 16 in a simplified state.

    [0029] In FIG. 1, the rotary machine 10 of the first embodiment has the rotating body 11, journal bearings 13, a thrust bearing 14, the plurality of impellers 16, a second shrink-fitting portion 18, and a casing 19.

    [0030] The rotating body 11 has a cylindrical shape and extends in the X-direction. The rotating body 11 is rotated about the axis O2 by a source of power such as an electric motor. The impellers 16 accommodated in the casing 19 are fitted onto the rotating body 11. Accordingly, the rotating body 11 rotates about the axis O2 along with the impellers 16.

    [0031] The rotating body 11 is rotatably supported by the journal bearings 13 and the thrust bearing 14 with respect to the casing 19.

    [0032] The journal bearings 13 are provided on both end portions of the rotating body 11 in the X-direction. The journal bearings 13 are disposed to oppose an outer circumferential surface of the rotating body 11.

    [0033] The thrust bearing 14 is provided on an end of the rotating body 11 positioned on a suction port 48 side to be described later.

    [0034] The plurality of impellers 16 are disposed at desired intervals in the X-direction. The plurality of impellers 16 are integrally fixed to the rotating body 11, and integrally rotate with the rotating body 11 along with the rotation of the rotating body 11. In a state of being fixed to the rotating body 11, the plurality of impellers 16 are accommodated inside the casing 19.

    [0035] FIG. 2 is a sectional view of an enlarged portion surrounded by the region A, out of structures shown in FIG. 1. In FIG. 2, the same configuration portions as the structures shown in FIG. 1 will be assigned with the same reference signs. B shown in FIG. 2 indicates a region where a recessed portion 33 and an engaging portion 35 are inserted (hereinafter, referred to as a "region B").

    [0036] FIG. 3 is a sectional view of an enlarged portion surrounded by the region B, out of structures shown in FIG. 2. In FIG. 3, the same configuration portions as the structures shown in FIG. 2 will be assigned with the same reference signs.

    [0037] FIG. 4 is a sectional view showing disassembled first and second disk members before shrink-fitting. In FIG. 4, the same configuration portions as the structures shown in FIGS. 1 to 3 will be assigned with the same reference signs.

    [0038] Herein, a configuration of each of the impellers 16 will be described with reference to FIGS. 1 to 4. Each of the impellers 16 is a closed impeller, and has the disk 21, blades 23, a cover 24, and a flow passage 25 in which the working fluid F flows.

    [0039] The disk 21 has a first disk member 26, a second disk member 27, and a first shrink-fitting portion 28.

    [0040]  The first disk member 26 has a tubular shape. The first disk member 26 has a first disk main body 31 and the recessed portion 33. The first disk main body 31 is a tubular member. The first disk main body 31 has a through-hole 31A into which the rotating body 11 is inserted, an inner circumferential surface 31a that defines the through-hole 31A, and an outer circumferential surface 31b.

    [0041] The outer circumferential surface 31b of the first disk main body 31 defines a part of the flow passage 25 between the cover 24 and the outer circumferential surface.

    [0042] The first disk main body 31 has a shape of which an outer diameter increases as going from one end 31B (an end positioned on the suction port 48 side) to the other end 31C (an end which is on a side of opposing the second disk member 27 and is positioned on a discharge port 53 side) of the first disk main body 31. The outer circumferential surface 31b is a curved inclined surface.

    [0043] The recessed portion 33 is formed by cutting the other end 31C of the first disk main body 31, which is to be described later, in the X-direction into a ring shape. Accordingly, the shape of the recessed portion 33 becomes a ring shape. In addition, the recessed portion 33 has the X-direction as a depth direction thereof.

    [0044] The recessed portion 33 has an inner circumferential surface 33a parallel to the outer circumferential surface 11a of the rotating body 11 and a bottom surface 33b orthogonal to the X-direction. The inner circumferential surface 33a is a surface that is not inclined in the X-direction (horizontal surface). The bottom surface 33b and the inner circumferential surface 33a are disposed in the first disk main body 31.

    [0045]  A portion of the inner circumferential surface 31a of the first disk main body 31, in which the recessed portion 33 is not formed, is shrink-fitted to the outer circumferential surface 11a of the rotating body 11. Accordingly, the first disk main body 31 is fixed to the rotating body 11.

    [0046] The second disk member 27 has a tubular shape. The second disk member 27 is a separate body from the first disk member 26, and is integrated with the plurality of impeller 16 and the casing 19.

    [0047] By making the first disk member 26, which is fixed to the rotating body 11, and the second disk member 27 separate bodies as described above, it becomes easy to insert a tool (not shown), which is used when forming the flow passage 25 to be disposed between the cover 24 and the second disk member 27, into the cover 24 and the second disk member 27. Therefore, the accuracy of the shape of the flow passage 25 can be enhanced.

    [0048] In addition, by integrating the second disk member 27, the blades 23, and the cover 24, work of combining the second disk member 27, the blades 23, and the cover 24 becomes unnecessary. Therefore, a decrease in the accuracy of the shape of the flow passage attributable to assembling work can be limited.

    [0049] The second disk member 27 has the engaging portion 35, a second disk main body 36, and a through-hole 38.

    [0050] The engaging portion 35 is a ring-shaped member which is integrated with the second disk main body 36, and extends in the X-direction. The engaging portion 35 has an outer circumferential surface 35a that comes into contact with the inner circumferential surface 33a of the recessed portion 33 when inserted in the recessed portion 33. The outer circumferential surface 35a is a surface that is not inclined in the X-direction (surface parallel to the X-direction).

    [0051] A thickness M1 of the engaging portion 35 in a radial direction of the disk 21 (direction orthogonal to the X-direction) is configured to be a thickness uniform in the X-direction and to be substantially equal to a width W1 of the recessed portion 33 in the radial direction of the disk 21.

    [0052] A length L1 of the engaging portion 35 in the X-direction is configured to be larger than a value of a depth D1 of the recessed portion in the X-direction. By configuring as described above, it becomes possible to form a gap 41 between the other end 31C of the first disk main body 31 (the first disk member 26) and the second disk main body 36 in a state where a tip surface 35b of the engaging portion 35 has abutted against the bottom surface 33b of the recessed portion 33.

    [0053] By forming the gap 41 between the first disk member 26 and the second disk main body 36 in the X-direction as described above, the occurrence of fretting (in this case, surface damage that occurs when minute reciprocating slide has repeatedly acted on between the first disk member 26 and the second disk member 27, which come into contact with each other) can be limited.

    [0054] The rotating body 11 is inserted in the engaging portion 35 in a state where the second disk member 27 and the first disk member 26 are shrink-fitted to each other.

    [0055] The second disk main body 36 is provided on a rear end of the engaging portion 35, which is positioned on an opposite side to the tip surface 35b. The second disk main body 36 is integrally configured with the engaging portion 35. The second disk main body 36 is erected from the outer circumferential surface 11a of the rotating body 11 in a radial direction of the rotating body 11. The second disk main body 36 is a donut-shaped plate member.

    [0056] The second disk main body 36 is configured such that a thickness in the X-direction becomes smaller as being separated away from the outer circumferential surface 11a of the rotating body 11. The second disk main body 36 has a surface 36a that defines the gap 41. The surface 36a opposes the other end 31C of the first disk main body 31 via the gap 41.

    [0057] The through-hole 38 is provided in the engaging portion 35 and the second disk main body 36. The rotating body 11 is inserted into the through-hole 38.

    [0058] The first shrink-fitting portion 28 is provided in a boundary portion between the inner circumferential surface 33a of the recessed portion 33 and the outer circumferential surface 35a of the engaging portion 35. The first shrink-fitting portion 28 is a portion formed by heating the outer circumferential surface 31b of the first disk main body 31 that defines the recessed portion 33 having an inner diameter smaller than an outer diameter of the engaging portion 35 to increase the inner diameter of the recessed portion 33 by means of thermal expansion and fitting the engaging portion 35 into the recessed portion 33 of which the inner diameter has increased.

    [0059] That is, the first shrink-fitting portion 28 refers to a portion made by bonding a portion of the first disk main body 31, which defines the inner circumferential surface 33a of the recessed portion 33, to a portion of the engaging portion 35, which defines the outer circumferential surface 35a, through shrink-fitting.

    [0060] By having the first shrink-fitting portion 28 disposed in the boundary portion between the outer circumferential surface 35a of the engaging portion 35 and the inner circumferential surface 33a of the recessed portion 33 as described above, it becomes possible to heat the outer circumferential surface 31b of the first disk main body 31 (an outer circumferential surface of a portion of the first disk member 26, which defines the recessed portion 33) and to form the first shrink-fitting portion 28. Accordingly, since it is not necessary to directly heat the second disk member 27 integrated with the blades 23 when forming the first shrink-fitting portion 28, deformation of the blades 23 attributable to the heating can be limited.

    [0061] The plurality of blades 23 are provided on a surface of the surface 36a of the second disk main body 36, which is separated away from the gap 41. The plurality of blades 23 are integrally configured with the second disk member 27. The plurality of blades 23 are radially disposed around the first disk member 26 in a circumferential direction of the second disk main body 36.

    [0062] The plurality of blades 23 protrude in a direction orthogonal to the surface 36a of the second disk main body 36, and extend in a direction toward a tip of the second disk main body 36. Each of the plurality of blades 23 is configured such that a protruding amount (in other words, a thickness) thereof decreases as going from the first disk member 26 to the tip of the second disk main body 36.

    [0063] Each of the plurality of blades 23 has a surface 23a disposed on an opposite side to a surface comes into contact with the surface 36a of the second disk main body 36.

    [0064] The cover 24 is a donut-shaped member, and has a through-hole 24A in a middle portion. The cover 24 is provided on the surface 23a of each of the plurality of blades 23. In this state, the through-hole 24A exposes the first disk member 26. The cover 24 covers the plurality of blades 23.

    [0065] By the first disk member 26 being disposed, a part of the through-hole 24A configures a part of the flow passage 25.

    [0066] The flow passage 25 is provided between the cover 24 and the second disk member 27. The flow passage 25 is defined by the blades 23, the cover 24, and the second disk member 27.

    [0067] The second shrink-fitting portion 18 is disposed in a boundary portion between the inner circumferential surface 31a of the first disk main body 31 (an inner circumferential surface of a portion of the first disk main body 31, in which the recessed portion 33 is not formed) and the outer circumferential surface 11a of the rotating body 11. The second shrink-fitting portion 18 fixes the first disk member 26 to the rotating body 11.

    [0068] The second shrink-fitting portion 18 is formed by heating (in other words, shrink-fitting) the outer circumferential surface 31b of the first disk main body 31 (an outer circumferential surface of a portion of the first disk main body 31, in which the recessed portion 33 is not formed). The second shrink-fitting portion 18 refers to a portion made by bonding a portion of the first disk main body 31, which defines the outer circumferential surface 31b of a portion of the first disk main body 31 in which the recessed portion 33 is not formed, to the outer circumferential surface 11a, which is a part of the rotating body 11, through shrink-fitting.

    [0069] For example, a shrink-fitting proportion of the second shrink-fitting portion 18 may be lower than a shrink-fitting proportion of the first shrink-fitting portion 28.

    [0070] By making the shrink-fitting proportion of the second shrink-fitting portion 18 formed after the first shrink-fitting portion 28 lower than the shrink-fitting proportion of the first shrink-fitting portion 28 as described above, it can be limited that heat attributable to heating performed when forming the second shrink-fitting portion 18 has an adverse effect on the first shrink-fitting portion 28.

    [0071] In FIG. 1, the casing 19 has a casing main body 46, a penetrated portion 47, a suction port 48, a flow passage 51, and a discharge port 53. The casing main body 46 accommodates the rotating body 11, the journal bearings 13, and the plurality of impellers 16.

    [0072] The penetrated portion 47 is a hole extending in the X-direction, and the rotating body 11 is inserted therein. The suction port 48 is provided on a side of one end portion of the casing main body 46. The suction port 48 functions as a suction port for sucking the working fluid F, which is a gas, into the casing 19 from the outside.

    [0073] The flow passage 51 is provided inside the casing main body 46. The flow passage 51 has one end connected to the suction port 48 and the other end connected to the discharge port 53. In addition, the flow passage 51 is also connected to the flow passage 25 of each of the impellers 16. Accordingly, the flow passage 51 is configured to allow the working fluid F to be supplied into the flow passage of each of the impellers 16.

    [0074] The discharge port 53 is provided on a side of the other end portion of the casing main body 46. The discharge port 53 functions as a discharge port for discharging the working fluid F, which flows in the casing 19, to the outside.

    [0075] In the impeller 16 according to the first embodiment, by making the first disk member 26, which is fixed to the rotating body 11, and the second disk member 27 separate bodies as described above, it becomes easy to insert the tool (not shown), which is used when forming the flow passage 25 to be disposed between the cover 24 and the second disk member 27, into the cover 24 and the second disk member 27. Therefore, the accuracy of the shape of the flow passage 25 can be enhanced.

    [0076] In addition, by integrating the second disk member 27, the blades 23, and the cover 24, work of combining the second disk member 27, the blades 23, and the cover 24 becomes unnecessary. Therefore, a decrease in the accuracy of the shape of the flow passage attributable to assembling work can be limited.

    [0077]  By having the first shrink-fitting portion 28 disposed in the boundary portion between the outer circumferential surface 35a of the engaging portion 35 and the inner circumferential surface 33a of the recessed portion 33 as described above, it becomes possible to heat the outer circumferential surface 31b of the first disk main body 31 (the outer circumferential surface of the portion of the first disk member 26, which defines the recessed portion 33) and to form the first shrink-fitting portion 28. Accordingly, since it is not necessary to directly heat the second disk member 27 integrated with the blades 23 when forming the first shrink-fitting portion 28, deformation of the blades 23 attributable to the heating can be limited.

    [0078] A position at which the disk 21 is divided into two portions (in other words, a dividing position between the first disk member 26 and the second disk member 27) may be on a through-hole 31A side of a region where the blades 23 are formed, and the dividing position between the first disk member 26 and the second disk member 27 is not limited to the dividing position shown in FIGS. 2 and 3.

    [0079] In addition, although a case where the bottom surface 33b of the recessed portion 33 abuts against the tip surface 35b of the engaging portion 35 such that the gap 41 is provided between the other end 31C of the first disk main body 31 and the surface 36a of the second disk main body 36 is given as an example and is shown in FIGS. 2 and 3, for example, the other end 31C of the first disk main body 31 may be brought into contact with the surface 36a of the second disk main body 36 such that the gap 41 is provided between the bottom surface 33b of the recessed portion 33 and the tip surface 35b of the engaging portion 35. Also in this case, fretting can be limited.

    [0080]  In the rotary machine 10 of the first embodiment, it is possible to provide the second shrink-fitting portion 18 at a position separated away from the first shrink-fitting portion 28. Thus, the impellers 16 can be fixed to the outer circumferential surface 11a of the rotating body 11 after limiting interference between the first shrink-fitting portion 28 and the second shrink-fitting portion 18. In addition, since the rotary machine 10 of the first embodiment includes the impellers 16 described above, the same effects as the impellers 16 can be obtained.

    [0081] FIG. 5 is a sectional view of enlarged main portions of an impeller according to a modification example of the first embodiment of the present invention. In FIG. 5, the same configuration portions as the structures shown in FIG. 3 will be assigned with the same reference signs.

    [0082] In FIG. 5, an impeller 55 of the modification example of the first embodiment is configured the same as the impeller 16 of the first embodiment described above except that the inner circumferential surface 33a of the recessed portion 33 and the outer circumferential surface 35a of the engaging portion 35 are inclined surfaces which are inclined in the X-direction.

    [0083] The inner circumferential surface 33a of the recessed portion 33 is an inclined surface, which is inclined in a direction where the inner diameter of the recessed portion 33 is narrowed (decreases) (a surface which is inclined in the X-direction) as going from the bottom surface 33b to the second disk main body 36 (a second disk member 27 side).

    [0084] The outer circumferential surface 35a of the engaging portion 35 is in contact with the inner circumferential surface 33a of the recessed portion 33, and is an inclined surface that causes a thickness of the engaging portion 35 to become smaller (lower surface inclined in the central axis O1 direction of the disk 21) as going from the tip surface 35b of the engaging portion 35 disposed on a first disk member 26 side to a second disk main body 36 side (as being separated away in the X-direction).

    [0085] In the impeller 55 according to the modification example of the first embodiment, it is possible to cause an anchoring effect in the first shrink-fitting portion 28 (an effect that the engaging portion 35 becomes unlikely to come out from the recessed portion 33 in the X-direction) by making the inner circumferential surface 33a of the recessed portion 33 an inclined surface inclined in a direction where the inner diameter of the recessed portion 33 is narrowed as going from the bottom surface 33b to the second disk main body 36, and making the outer circumferential surface 35a of the engaging portion 35 an inclined surface that causes the thickness of the engaging portion 35 to become smaller as going from the tip surface 35b of the engaging portion 35 disposed on the first disk member 26 side to the second disk main body 36 side. Thus, the strength of connection between the first disk member 26 and the second disk member 27 can be improved.

    [0086] Although a case where the gap 41 is provided between the other end 31C of the first disk main body 31 and the surface 36a of the second disk main body 36 in each of the impellers 16 and 55 described above is given and described as an example, the gap 41 may be provided between the bottom surface 33b and the tip surface 35b by abutting the other end 31C of the first disk main body 31 against the surface 36a of the second disk main body 36 such that the bottom surface 33b of the recessed portion 33 and the tip surface 35b of the engaging portion 35 are separated away from each other in the X-direction. Also in a case where such a configuration is adopted, fretting can be limited.

    [0087] FIGS. 6 to 8 are sectional views showing a method for manufacturing an impeller according to the first embodiment of the present invention. In FIGS. 6 to 8, the same configuration portions as the structures shown in FIGS. 2 to 4 will be assigned with the same reference signs. In FIG. 8, E indicates a region of the outer circumferential surface 31b of the first disk main body 31, which is heated at the time of a first shrink-fitting step (hereinafter, referred to as a "region E"). In addition, F shown in FIG. 8 indicates a region of the outer circumferential surface 31b of the first disk main body 31, which is heated at the time of a second shrink-fitting step (hereinafter, referred to as a "region F").

    [0088] With reference to FIGS. 1 to 4, and FIGS. 6 to 8, a method for manufacturing the rotary machine 10 of the first embodiment will be described. While describing the method for manufacturing the rotary machine 10 of the first embodiment, a method for manufacturing the impeller 16 of the first embodiment will be described.

    [0089] First, in a step shown in FIG. 6, the tubular first disk member 26 having the ring-shaped recessed portion 33 is formed inside through a known technique.

    [0090] Next, in a step shown in FIG. 7, a structure 67, in which the second disk member 27 having the ring-shaped engaging portion 35 that engages with the first disk member 26 by being inserted into the recessed portion 33, the blades 23 provided on the second disk member 27, and the cover 24 that is provided on the blades and covers the blades 23 are integrated, is formed.

    [0091] Specifically, the structure 67, in which is the second disk member 27, the blades 23, and the cover 24 are integrated, is formed by processing a base material of the structure 67 with the use of a tool 65 having a rotating processing portion 66.

    [0092] Since the first disk member 26 shown in FIG. 6 and the second disk member 27 shown in FIG. 7 are separate bodies when forming the structure 67, it is easy to insert the processing portion 66 of the tool 65 between the cover 24 and the second disk member 27. Accordingly, it is possible to easily process the flow passage 25 to be formed between the cover 24 and the second disk member 27. Accordingly, the accuracy of the shape of the flow passage 25 can be enhanced.

    [0093] In a step of forming the structure 67, for example, the length L1 of the engaging portion 35 may be formed to be larger than the depth D1 of the recessed portion 33. Accordingly, when the engaging portion 35 shown in FIG. 8 is inserted in the recessed portion 33 shown in FIG. 7, the gap 41 shown in FIGS. 2 and 3 can be formed, and thus the occurrence of fretting can be limited.

    [0094] Next, in a step shown in FIG. 8, the outer circumferential surface 35a of the engaging portion 35 is shrink-fitted to the inner circumferential surface 33a of the recessed portion 33 by inserting the engaging portion 35 configuring the structure 67 into the recessed portion 33 and heating the first disk main body 31 corresponding to the region E from an outer circumferential surface 31b side of the first disk main body 31 at a desired heating temperature (hereinafter, referred to as a "heating temperature T1") (first shrink-fitting step).

    [0095] At this time, the first shrink-fitting portion 28 is formed in the boundary portion between the outer circumferential surface 35a of the engaging portion 35 and the inner circumferential surface 33a of the recessed portion 33. Accordingly, the impeller 16 of the first embodiment are manufactured (step of preparing an impeller).

    [0096] Next, as shown in FIGS. 2 and 3, the rotating body 11 is inserted into the through-holes 31A and 38 of the impellers 16, and the plurality of impellers 16 are disposed at desired positions in the rotating body 11. Next, the portion of the inner circumferential surface 31a of the first disk main body 31, in which the recessed portion 33 is not formed, is shrink-fitted to the outer circumferential surface 11a of the rotating body 11 by heating the first disk main body 31 corresponding to the region F shown in FIG. 8 (portion where the recessed portion is not formed) from the outer circumferential surface 31b side of the first disk main body 31 (second shrink-fitting step).

    [0097] At this time, the second shrink-fitting portion 18 is formed in the boundary portion between the inner circumferential surface 31a of the first disk main body 31 and the outer circumferential surface 11a of the rotating body 11. Accordingly, since it becomes not necessary to directly heat the second disk member 27 integrated with the blades 23 by heating the outer circumferential surface 31b of the first disk main body 31 corresponding to the region F in a state where the rotating body 11 is inserted in the through-holes 31A and 38 of the impeller 16 as described above, deformation of the blades 23 attributable to the heating can be limited.

    [0098] For example, a heating temperature T2 when heating the first disk main body 31 in the second shrink-fitting step may be lower than the heating temperature T1 when heating the first disk main body 31 in the first shrink-fitting step.

    [0099] By making the heating temperature T2 when forming the second shrink-fitting portion 18 which is formed after the first shrink-fitting portion 28 lower than the heating temperature T1 when forming the first shrink-fitting portion 28 as described above, it can be limited that the heating temperature T2 when forming the second shrink-fitting portion 18 has an adverse effect on the first shrink-fitting portion 28 and the strength of bonding between the first disk member 26 and the second disk member 27 decreases.

    [0100] Next, as shown in FIG. 1, the structures shown in FIG. 2 are accommodated in the casing 19, the rotating body 11 is disposed in the penetrated portion 47, and the rotating body 11 is supported by the journal bearings 13 and the thrust bearing 14. At this time, the flow passages (not shown) provided in the plurality of impellers 16 are connected to the flow passage 51 formed in the casing 19. Accordingly, the rotary machine 10 of the first embodiment is manufactured.

    [0101] In the method for manufacturing the impeller 16 of the first embodiment, by forming the first disk member 26 and the second disk member 27 as separate bodies, it becomes easy to insert the processing portion 66 of the tool 65, which is used when forming the flow passage 25 to be disposed between the cover 24 and the second disk member 27, into the cover 24 and the second disk member 27. Therefore, the accuracy of the shape of the flow passage 25 can be enhanced.

    [0102] In addition, by integrally forming the second disk member 27, the blades 23, and the cover 24, work of combining the second disk member 27, the blades 23, and the cover 24 becomes unnecessary. Therefore, a decrease in the accuracy of the shape of the flow passage attributable to assembling work can be limited.

    [0103] The impeller 55 of the modification example of the first embodiment described above can be manufactured through the same technique as the method for manufacturing the impeller 16 of the first embodiment except that the inner circumferential surface 33a and the outer circumferential surface 35a are processed to be inclined surfaces.

    (Second Embodiment)



    [0104] FIG. 9 is a sectional view of an impeller according to a second embodiment of the present invention. FIG. 9 also shows the rotating body 11 which is a configuration element other than an impeller 60. In FIG. 9, the same configuration portions as the structures shown in FIGS. 2 to 4 will be assigned with the same reference signs.

    [0105] FIG. 10 is a sectional view of an enlarged portion of the impeller shown in FIG. 9, which is surrounded by a region C. In FIG. 10, the same configuration portions as the structures shown in FIGS. 2 to 4 and FIG. 9 will be assigned with the same reference signs.

    [0106] In FIGS. 9 and 10, the impeller 60 of the second embodiment is configured the same as the impeller 16 except that a positioning key 61 and a key insertion hole 63 are provided in the configuration of the impeller 16 of the first embodiment.

    [0107] The positioning key 61 is a metal pin. The positioning key 61 is provided in the engaging portion 35 so as to protrude from the tip surface 35b in the X-direction.

    [0108] The key insertion hole 63 is provided in a portion of the first disk main body 31, which opposes the positioning key 61. The key insertion hole 63 is a hole extending in the X-direction. A portion of the positioning key 61, which protrudes from the tip surface 35b is inserted in the key insertion hole 63.

    [0109] By the impeller 60 of the second embodiment having the positioning key 61, which is provided in the engaging portion 35 and protrudes from the tip surface 35b in the X-direction, and the key insertion hole 63, which is provided in the first disk main body 31 and into which a part of the positioning key 61 is inserted, positioning between the first disk member 26 and the second disk member 27 (positioning in a rotation direction of which a rotation axis is the central axis O1) can be easily performed.

    [0110] One or more positioning keys 61 and one or more key insertion holes 63 that are described above may be provided in a circumferential direction of the disk 21.

    [0111] In the impeller 60 of the second embodiment, the inclined inner circumferential surface 33a and the inclined outer circumferential surface 35a which are shown in FIG. 5 may be used. In this case, the same effects as the impeller 55 according to the modification example of the first embodiment described above can be obtained.

    [0112] In addition, the impeller 60 of the second embodiment can be manufactured through the same technique as the method for manufacturing the impeller 16 of the first embodiment described above except that the first shrink-fitting step is performed after the first and second disk members 26 and 27 are formed and then the positioning key 61 is inserted into the key insertion hole 63.

    (Third Embodiment)



    [0113] FIG. 11 is a sectional view showing an impeller according to a third embodiment of the present invention. In FIG. 11, the same configuration portions as the structures shown in FIGS. 2 to 4 will be assigned with the same reference signs. In addition, FIG. 11 schematically shows a state where an impeller 70 is shrink-fitted to the rotating body 11. In FIG. 11, O1 indicates a central axis of a disk 71 (hereinafter, referred to as the "central axis O1").

    [0114] FIG. 12 is a sectional view of an enlarged portion surrounded by a region G, out of structures shown in FIG. 11. In FIG. 12, the same configuration portions as the configurations shown in FIGS. 2 to 4 and FIG. 11 will be assigned with the same reference signs.

    [0115] In FIGS. 11 and 12, the impeller 70 of the third embodiment is configured the same as the impeller 16 except that the disk 71 is included instead of the disk 21 configuring the impeller 16 of the first embodiment.

    [0116] The disk 71 has a first disk member 73 and a second disk member 75. The first disk member 73 is configured the same as the first disk member 26 except that a recessed portion 81 having a plurality of steps (for example, two steps in a case of FIGS. 11 and 12) is included instead of the recessed portion 33 configuring the first disk member 26 described in the first embodiment.

    [0117] The recessed portion 81 includes a first recessed portion 81A and a second recessed portion 81B. The first recessed portion 81A is disposed on a bottom surface 81c side of the recessed portion 81. A bottom surface 81c functions as a bottom surface of the first recessed portion 81A. The bottom surface 81c is a surface orthogonal to the X-direction.

    [0118] The first recessed portion 81A has an inner circumferential surface 81a orthogonal to the bottom surface 81c. The first recessed portion 81A is defined by the bottom surface 81c and the inner circumferential surface 81a.

    [0119] The second recessed portion 81B is integrally configured with the first recessed portion 81A, and is exposed from the other end 31C of the first disk main body 31. The second recessed portion 81B is a recessed portion having a larger diameter than the first recessed portion 81A.

    [0120] The second recessed portion 81B has an inner circumferential surface 81b, which is larger than an inner diameter of the inner circumferential surface 81a, and a bottom surface 81Ba. The bottom surface 81Ba is a surface orthogonal to the X-direction. The bottom surface 81Ba is connected to the inner circumferential surface 81b, and is orthogonal to the inner circumferential surface 81b.

    [0121] The first disk member 75 is configured the same as the second disk member 27 except that an engaging portion 83 having a plurality of step portions (for example, two step portions in the case of FIGS. 11 and 12) that can be inserted into the recessed portion 81 is included instead of the engaging portion 35 configuring the second disk member 27 described in the first embodiment.

    [0122] The engaging portion 83 is a cylindrical member extending in the X-direction, and is inserted into the recessed portion 81. An inner circumferential surface of the engaging portion 83 is in contact with the outer circumferential surface 11a of the rotating body 11. The engaging portion 83 has a first step portion 88 and a second step portion 89.

    [0123] The first step portion 88 is inserted in the first recessed portion 81A. The first step portion 88 has a tip surface 88a abutting against the bottom surface 81c and an inner circumferential surface 88b that comes into contact with the inner circumferential surface 81a of the first recessed portion 81A. It is possible to set a thickness M2 of the first step portion 88 to a thickness that is the same as, for example, the thickness M1 of the engaging portion 35 described in the first embodiment.

    [0124] The second step portion 89 is a tubular member having an outer circumferential portion of which a diameter is larger than the first step portion 88. The second step portion 89 is inserted in the second recessed portion 81B. The thickness M2 of the first step portion 88 is smaller than the thickness M3 of the second step portion 89.

    [0125] The second step portion 89 has a tip surface 89a having a gap 85 interposed between the bottom surface 81Ba of the second recessed portion 81B and the tip surface and an outer circumferential surface 89b comes into contact with the inner circumferential surface 81b of the second recessed portion 81B. The gap 41 is formed between the other end 31C of the first disk main body 31 and the surface 36a of the second disk main body 36.

    [0126] That is, the engaging portion 83 has the first and second step portions 88 and 89 (the plurality of step portions) having distances from the central axis O1 of the disk 71 to the outer circumferential surfaces 88b and 89b of the engaging portion 83 in the X-direction, which are different from each other.

    [0127] By abutting the tip surface 88a of the first step portion 88 against the bottom surface 81c of the first recessed portion 81A such that the gap 85 is provided between the tip surface 89a of the second step portion 89 and the bottom surface 81Ba of the second recessed portion 81B and the gap 41 is provided between the other end 31C of the first disk main body 31 and the surface 36a of the second disk main body 36 as described above, the occurrence of fretting (in this case, surface damage that occurs when minute reciprocating slide repeatedly acts between the first disk member 73 and the second disk member 75) can be limited.

    [0128] In the impeller 70 of the third embodiment, in a case where a width of the inner circumferential surface 88b of the first step portion 88 in the X-direction is the same as a width of the outer circumferential surface 89b of the second step portion 89 disposed on an outer side of the inner circumferential surface 88b in the X-direction, the outer circumferential surface 89b disposed on the outer side has a wider area.

    [0129]  Accordingly, for example, in a case where the thickness M1 of the engaging portion 35 having the outer circumferential surface 35a shown in FIG. 2 is equal to the thickness M2 of the first step portion 88 and a total area of the outer circumferential surface of the engaging portion 35 and a total area of the outer circumferential surfaces of the engaging portion 83 are obtained as the same area (desired area), it is possible to make the length L2 of the engaging portion 83 having the two inner circumferential surface 88b and 89b smaller than the length L1 of the engaging portion 35 having the only one outer circumferential surface 35a. Thus, the length L2 of the engaging portion 83 in the X-direction can be made small.

    [0130] It is possible to manufacture the impeller 70 of the third embodiment through the same technique as the method for manufacturing the impeller 16 described in the first embodiment, and the same effects as the method for manufacturing the impeller 16 of the first embodiment can be obtained.

    [0131] In the impeller 70 of the third embodiment, the inclined inner circumferential surface 33a and the inclined outer circumferential surface 35a which are shown in FIG. 5 may be used. In this case, the same effects as the impeller 55 according to the modification example of the first embodiment described above can be obtained.

    [0132] FIG. 13 is a sectional view of enlarged main portions of an impeller according to a modification example of the third embodiment of the present invention. In FIG. 13, the same configuration portions as the structures shown in FIG. 12 will be assigned with the same reference signs.

    [0133]  In FIG. 13, an impeller 90 according to the modification example of the third embodiment is configured the same as the impeller 70 of the third embodiment except that the gap 41 is disposed between the bottom surface 81c and the tip surface 88a by abutting the other end 31C of the first disk main body 31 against the surface 36a of the second disk main body 36 and separating the bottom surface 81c of the recessed portion 81 away from the tip surface 88a of the first step portion 88 in the X-direction.

    [0134] The impeller 90 according to the modification example of the third embodiment which is configured as described above can obtain the same effects as the impeller 70 of the third embodiment described above.

    [0135] In a case where the engaging portion 83 has the plurality of (for example, two in a case of FIG. 13) step portions as described above, the occurrence of fretting can be limited insofar as a configuration where one of the plurality of step portions and the second disk main body 36 abuts against the first disk main body 31 in the X-direction such that a gap is interposed between the first disk main body 31 and the rest in the X-direction is adopted.

    [0136] In the impeller 90 of the modification example of the third embodiment, the inclined inner circumferential surface 33a and the inclined outer circumferential surface 35a which are shown in FIG. 5 may be used. In this case, the same effects as the impeller 55 according to the modification example of the first embodiment described above can be obtained.

    [0137] It is possible to manufacture the impeller 90 according to the modification example of the third embodiment through the same technique as the method for manufacturing the impeller 16 described in the first embodiment, and the same effects as the method for manufacturing the impeller 16 of the first embodiment can be obtained.

    Industrial Applicability



    [0138] After integrally configuring the second disk member, which is a separate body from the first disk member, the blades, and the cover, the present invention is applicable to an impeller, a rotary machine, a method for manufacturing an impeller, and a method for manufacturing a rotary machine, in which the accuracy of the shape of the flow passage disposed between the second disk member and the cover can be enhanced.

    Reference Signs List



    [0139] 
    10:
    rotary machine
    11:
    rotating body
    11a, 31b, 35a, 88b, 89b:
    outer circumferential surface
    13:
    journal bearing
    14:
    thrust bearing
    16, 55, 60, 70, 90:
    impeller
    18:
    second shrink-fitting portion
    19:
    casing
    21, 71:
    disk
    23:
    blade
    23a, 36a:
    surface
    24:
    cover
    24A, 31A, 38:
    through-hole
    25:
    flow passage
    26, 73:
    first disk member
    27, 75:
    second disk member
    28:
    first shrink-fitting portion
    31:
    first disk main body
    31a, 33a, 81a, 81b:
    inner circumferential surface
    31B:
    one end
    31C:
    the other end
    33, 81:
    recessed portion
    33b, 81c, 81Ba:
    bottom surface
    35, 83:
    engaging portion
    35b, 88a, 89a:
    tip surface
    36:
    second disk main body
    41, 85:
    gap
    46:
    casing main body
    47:
    penetrated portion
    48:
    suction port
    51:
    flow passage
    53:
    discharge port
    61:
    positioning key
    63:
    key insertion hole
    65:
    tool
    66:
    processing portion
    67:
    structure
    81A:
    first recessed portion
    81B:
    second recessed portion
    88:
    first step portion
    89:
    second step portion
    A, B, C, E, F, G:
    region
    F:
    working fluid
    D1:
    depth
    L1, L2:
    length
    M1, M2, M3:
    thickness
    O1:
    central axis
    O2:
    axis
    T1, T2:
    heating temperature
    W1:
    width



    Claims

    1. An impeller (16; 55; 60; 70; 90) comprising:

    a disk (21; 71) that has tubular first and second disk members (26, 27; 73, 75);

    a blade (23) that is integrally provided with the second disk member (27; 75); and

    a cover (24) that is integrally provided with the blade (23) and defines a flow passage (25) between the second disk member (27; 75) and the cover (24),

    wherein the first disk member (26; 73) defines a part of the flow passage (25) and has a ring-shaped recessed portion (33; 81), that has a central axis direction (X) of the disk (21; 71) as a depth direction (X) thereof,

    the second disk member (27; 75) has a ring-shaped engaging portion (35; 83) that is configured to engage with the first disk member (26; 73) by being inserted into the recessed portion (33; 81),

    both the first and second disk members (26, 27; 73, 75) each comprise a through hole (31A, 38), the through-holes (31A, 38) being configured such that a rotating body (11) can be inserted into both through-holes (31A, 38);

    a first shrink-fitting portion (28) is provided in a boundary portion between an outer circumferential surface (35a; 88b, 89b) of the engaging portion (35; 83) and an inner circumferential surface (33a; 81a, 81b) of the recessed portion (33; 81), the inner circumferential surface (33a; 81a, 81b) coming into contact with the outer circumferential surface (35a; 88b, 89b) of the engaging portion (35; 83),

    characterized in that the second disk member (27; 75) has a portion abutting against the first disk member (26; 73) in the central axis direction (X) of the disk (21; 71) and a portion forming a gap (41) between the first disk member (26; 73) and the second disk member (27; 75) in the central axis direction (X) of the disk (21; 71).


     
    2. The impeller according to Claim 1,
    wherein the engaging portion (83) has a plurality of step portions (88, 89) having different distances from a central axis (O1) of the disk (71) to the outer circumferential surface (88b, 89b) of the engaging portion (83) in the central axis direction (X) of the disk (71), and
    a shape of the recessed portion (81) is a shape that is configured to allow the recessed portion (81) to be engaged with the plurality of step portions (88, 89).
     
    3. The impeller according to Claim 1 or 2,
    wherein the inner circumferential surface (33a; 81a, 81b) of the recessed portion (33; 81) is an inclined surface that is inclined in a direction where an inner diameter of the recessed portion (33; 81) is narrowed as going from a bottom surface (33b; 81c, 81Ba) of the recessed portion (33; 81) to a second disk member side, and
    the outer circumferential surface (35a; 88b, 89b) of the engaging portion (35; 83) is an inclined surface that is configured to cause a thickness of the engaging portion (35; 83) to become smaller as being separated away from a tip surface (35b; 88a, 89a) of the engaging portion (35; 83), which is disposed on a first disk member side, in the central axis direction (X) of the disk (21; 71).
     
    4. The impeller according to-any one of Claims 1 to 3,
    wherein a positioning key (61) is provided inside a portion where the first disk member (26) has abutted against the second disk member (27) in the central axis direction (X) of the disk (21).
     
    5. A rotary machine comprising:

    the impeller according to any one of Claims 1 to 4; and

    a rotating body (11) which is configured to rotate about an axis (O2) matching a central axis (O1) of the disk (21; 71) as a rotation axis and to which the impeller (16; 55; 60; 70; 90) is fixed,

    wherein a second shrink-fitting portion (18) is provided in a boundary portion between an inner circumferential surface (31a) of a portion of the first disk member (26; 73), in which the recessed portion (33; 81) is not formed, and an outer circumferential surface (11a) of the rotating body (11).


     
    6. The rotary machine according to Claim 5,
    wherein a shrink-fitting proportion of the second shrink-fitting portion (18) is lower than a shrink-fitting proportion of the first shrink-fitting portion (28).
     
    7. A method for manufacturing an impeller, comprising:

    a step of forming a tubular first disk member (26; 73) having a ring-shaped recessed portion (33; 81) therein;

    a step of forming a structure (67) in which a second disk member (27; 75) having a ring-shaped engaging portion (35; 83) that is configured to engage with the first disk member (26; 73) by being inserted into the recessed portion (33; 81), and configures a disk with the first disk member (26; 73), a blade (23) provided on the second disk member (27; 75), and a cover (24) that is provided on the blade, covers the blade (23), and defines a flow passage (25) between the second disk member (27; 75) and the cover (24) are integrated; and

    a first shrink-fitting step of shrink-fitting a boundary portion between an outer circumferential surface (35a; 88b, 89b) of the engaging portion (35; 83) and an inner circumferential surface (33a; 81a, 81b) of the recessed portion (33; 81) by inserting the engaging portion (35; 83) configuring the structure (67) into the recessed portion (33; 81) and heating the first disk member (26; 73) from an outer circumferential surface side (31b) of the first disk member (26; 73),

    wherein both the first and second disk members (26, 27; 73, 75) each comprise a through hole (31A, 38), the through-holes (31A, 38) being configured such that a rotating body (11) can be inserted into both through-holes (31A, 38);

    characterized in that in the step of forming the structure (67), a length (L1, L2) of the engaging portion (35; 83) in the central axis direction (X) of the disk (21; 71) is made larger than a depth (D1) of the recessed portion (33; 81) in the central axis direction (X) of the disk (21; 71) such that a portion where the first disk member (26; 73) abuts against the second disk member (27; 75) is formed and a gap (41) is formed between the first disk member (26; 73) and the second disk member (27; 75).


     
    8. A method for manufacturing a rotary machine, comprising:

    a step of preparing an impeller (16; 55; 60; 70; 90) manufactured through the method for manufacturing an impeller (16; 55; 60; 70; 90) according to Claim 7; and

    a second shrink-fitting step of shrink-fitting a boundary portion between an inner circumferential surface (31a) of a portion of the first disk member (26; 73), in which the recessed portion (33; 81) is not formed, and an outer circumferential surface (11a) of a rotating body (11) by heating the first disk member (26; 73) from an outer circumferential surface side (31b) of the portion in which the recessed portion (33; 81) is not formed in a state where the rotating body (11) is inserted in the impeller (16; 55; 60; 70; 90).


     
    9. The method for manufacturing a rotary machine according to Claim 8,
    wherein a heating temperature (T2) of the first disk member (26; 73) in the second shrink-fitting step is lower than a heating temperature (T1) of the first disk member (26; 73) in the first shrink-fitting step.
     


    Ansprüche

    1. Laufrad (16; 55; 60; 70; 90) umfassend:

    eine Scheibe (21; 71), die röhrenförmige erste und zweite Scheibenelemente (26, 27; 73, 75) hat;

    eine Schaufel (23), die einstückig an dem zweiten Scheibenelement (27; 75) vorgesehen ist; und

    eine Abdeckung (24), die einstückig an der Schaufel (23) vorgesehen ist und einen Strömungskanal (25) zwischen dem zweiten Scheibenelement (27; 75) und der Abdeckung (24) definiert,

    wobei das erste Scheibenelement (26; 73) einen Teil des Strömungskanals (25) definiert und einen ringförmigen ausgesparten Abschnitt (33; 81) hat, der eine Mittelachsenrichtung (X) der Scheibe (21; 71) als eine Tiefenrichtung (X) davon hat,

    das zweite Scheibenelement (27; 75) einen ringförmigen Eingriffsabschnitt (35; 83) hat, der dazu eingerichtet ist, durch Einführen in den ausgesparten Abschnitt (33; 81) mit dem ersten Scheibenelement (26; 73) in Eingriff zu kommen,

    sowohl das erste als auch das zweite Scheibenelement (26, 27; 73, 75) jeweils ein Durchgangsloch (31A, 38) aufweisen, wobei die Durchgangslöcher (31A, 38) dazu eingerichtet sind, dass ein Drehkörper (11) in beide Durchgangslöcher (31A, 38) eingeführt werden kann;

    ein erster Aufschrumpfabschnitt (28) in einem Grenzabschnitt zwischen einer äußeren Umfangsfläche (35a; 88b, 89b) des Eingriffsabschnitts (35; 83) und einer inneren Umfangsfläche (33a; 81a, 81b) des ausgesparten Abschnitts (33; 81) vorgesehen ist, wobei die innere Umfangsfläche (33a; 81a, 81b) in Kontakt mit der äußeren Umfangsfläche (35a; 88b, 89b) des Eingriffsabschnitts (35; 83) kommt,

    dadurch gekennzeichnet, dass das zweite Scheibenelement (27; 75) einen Abschnitt, der an dem ersten Scheibenelement (26; 73) in der Mittelachsenrichtung (X) der Scheibe (21; 71) anliegt, und einen Abschnitt aufweist, der einen Spalt (41) zwischen dem ersten Scheibenelement (26; 73) und dem zweiten Scheibenelement (27; 75) in der Mittelachsenrichtung (X) der Scheibe (21; 71) bildet.


     
    2. Laufrad nach Anspruch 1,
    wobei der Eingriffsabschnitt (83) eine Vielzahl von Stufenabschnitten (88, 89) aufweist, die unterschiedliche Abstände von einer zentralen Achse (O1) der Scheibe (71) zu der äußeren Umfangsfläche (88b, 89b) des Eingriffsabschnitts (83) in der Mittelachsenrichtung (X) der Scheibe (71) haben, und
    eine Form des ausgesparten Abschnitts (81) eine Form ist, die dazu eingerichtet ist, dass der ausgesparte Abschnitt (81) mit der Vielzahl von Stufenabschnitten (88, 89) in Eingriff kommen kann.
     
    3. Laufrad nach Anspruch 1 oder 2,
    wobei die innere Umfangsfläche (33a; 81a, 81b) des ausgesparten Abschnitts (33; 81) eine geneigte Fläche ist, die in einer Richtung geneigt ist, in der sich ein Innendurchmesser des ausgesparten Abschnitts (33; 81) von einer Bodenfläche (33b; 81c, 81Ba) des ausgesparten Abschnitts (33; 81) zu einer zweiten Scheibenelementseite hin verengt, und
    die äußere Umfangsfläche (35a; 88b, 89b) des Eingriffsabschnitts (35; 83) eine geneigte Fläche ist, die dazu eingerichtet ist, zu bewirken, dass eine Dicke des Eingriffsabschnitts (35; 83) kleiner wird, wenn er von einer Spitzenoberfläche (35b; 88a, 89a) des Eingriffsabschnitts (35; 83), die auf einer ersten Scheibenelementseite angeordnet ist, in der Mittelachsenrichtung (X) der Scheibe (21; 71) getrennt wird.
     
    4. Laufrad nach einem der Ansprühe 1 bis 3,
    wobei ein Positionierungsschlüssel (61) in einem Abschnitt vorgesehen ist, wo das erste Scheibenelement (26) an das zweite Scheibenelement (27) in der Mittelachsenrichtung (X) der Scheibe (21) anliegt.
     
    5. Drehmaschine umfassend:

    das Laufrad nach einem der Ansprüche 1 bis 4; und

    einen Drehkörper (11), der dazu eingerichtet ist, sich um eine Achse (O2) zu drehen, die einer zentralen Achse (O1) der Scheibe (21; 71) als Rotationsachse entspricht und an welcher das Laufrad (16; 55; 60; 70; 90) befestigt ist, wobei ein zweiter Aufschrumpfabschnitt (18) in einem Grenzabschnitt zwischen einer inneren Umfangsfläche (31a) eines Abschnitts des ersten Scheibenelements (26; 73), in welchem der ausgesparte Abschnitt (33; 81) nicht gebildet ist, und einer äußeren Umfangsfläche (11a) des Drehkörpers (11) vorgesehen ist.


     
    6. Drehmaschine nach Anspruch 5,
    wobei ein Aufschrumpfanteil des zweiten Aufschrumpfabschnitts (18) geringer ist als ein Aufschrumpfanteil des ersten Aufschrumpfabschnitts (28).
     
    7. Verfahren zum Herstellen eines Laufrads, umfassend:

    einen Schritt des Bildens eines röhrenförmigen ersten Scheibenelements (26; 73) mit einem ringförmigen ausgesparten Abschnitt (33; 81) darin;

    einen Schritt des Bildens einer Struktur (67), bei dem ein zweites Scheibenelement (27; 75) mit einem ringförmigen Eingriffsabschnitt (35; 83), der dazu eingerichtet ist, durch Einführen in den ausgesparten Abschnitt (33; 81) mit dem ersten Scheibenelement (26; 73) in Eingriff zu kommen und eine Scheibe mit dem ersten Scheibenelement (26; 73) ausbildet, eine Schaufel (23), die an dem zweiten Scheibenelement (27; 75) vorgesehen ist, und eine Abdeckung (24), die an der Schaufel vorgesehen ist, die Schaufel (23) abdeckt und einen Strömungskanal (25) zwischen dem zweiten Scheibenelement (27; 75) und der Abdeckung (24) definiert, integriert werden; und

    einen ersten Aufschrumpfschritt des Aufschrumpfens eines Grenzabschnitts zwischen einer äußeren Umfangsfläche (35a; 88b, 89b) des Eingriffsabschnitts (35; 83) und einer inneren Umfangsfläche (33a; 81a, 81b) des ausgesparten Abschnitts (33; 81) durch Einführen des Eingriffsabschnitts (35; 83), der die Struktur (67) konfiguriert, in den ausgesparten Abschnitt (33; 81) und Erwärmen des ersten Scheibenelements (26; 73) von einer äußeren Umfangsflächenseite (31b) des ersten Scheibenelements (26; 73),

    wobei sowohl das erste als auch das zweite Scheibenelement (26, 27; 73, 75) jeweils ein Durchgangsloch (31A, 38) aufweisen, wobei die Durchgangslöcher (31A, 38) so eingerichtet sind, dass ein Drehkörper (11) in beide Durchgangslöcher (31A, 38) eingeführt werden kann;

    dadurch gekennzeichnet, dass in dem Schritt des Bildens der Struktur (67) eine Länge (L1, L2) des Eingriffsabschnitts (35; 83) in der Mittelachsenrichtung (X) der Scheibe (21; 71) größer gemacht wird als eine Tiefe (D1) des ausgesparten Abschnitts (33; 81) in der Mittelachsenrichtung (X) der Scheibe (21; 71), so dass ein Abschnitt, wo das erste Scheibenelement (26; 73) an dem zweiten Scheibenelement (27; 75) anliegt, gebildet wird und ein Spalt (41) zwischen dem ersten Scheibenelement (26; 73) und dem zweiten Scheibenelement (27; 75) gebildet wird.


     
    8. Verfahren zum Herstellen einer Drehmaschine, umfassend:

    einen Schritt des Bereitstellens eines Laufrads (16; 55; 60; 70; 90), hergestellt durch das Verfahren zum Herstellen eines Laufrads (16; 55; 60; 70; 90) nach Anspruch 7; und

    einen zweiten Aufschrumpfschritt des Aufschrumpfens eines Grenzabschnitts zwischen einer inneren Umfangsfläche (31a) eines Abschnitts des ersten Scheibenelements (26; 73), in welchem der ausgesparte Abschnitt (33; 81) nicht gebildet ist, und einer äußeren Umfangsfläche (11a) eines Drehkörpers (11) durch Erwärmen des ersten Scheibenelements (26; 73) von einer äußeren Umfangsflächenseite (31b) des Abschnitts, in welchem der ausgesparte Abschnitt (33; 81) nicht gebildet ist in einem Zustand, in dem der Drehkörper (11) in das Laufrad (16; 55; 60; 70; 90) eingeführt ist.


     
    9. Verfahren zum Herstellen einer Drehmaschine nach Anspruch 8,
    wobei eine Heiztemperatur (T2) des ersten Scheibenelements (26; 73) in dem zweiten Aufschrumpfschritt kleiner ist als eine Heiztemperatur (T1) des ersten Scheibenelements (26; 73) in dem ersten Aufschrumpfschritt.
     


    Revendications

    1. Turbine (16 ; 55 ; 60 ; 70 ; 90) comprenant :

    un disque (21 ; 71) qui possède des premier et second éléments disques tubulaires (26, 27 ; 73, 75) ;

    une pale (23) qui est solidaire du second élément disque (27 ; 75) ; et

    un capot (24) qui est solidaire de la pale (23) et définit un passage d'écoulement (25) entre le second élément disque (27 ; 75) et le capot (24),

    dans laquelle le premier élément disque (26 ; 73) définit une partie du passage d'écoulement (25) et possède une portion évidée à géométrie annulaire (33 ; 81), qui possède une direction d'axe central (X) du disque (21 ; 71) en tant que sa direction de profondeur (X),

    le second élément disque (27 ; 75) possède une portion de mise en prise à géométrie annulaire (35 ; 83) qui est configurée pour venir en prise avec le premier élément disque (26 ; 73) en étant insérée dans la portion évidée (33 ; 81),

    à la fois les premier et second éléments disques (26, 27 ; 73, 75) comprennent chacun un trou traversant (31A, 38), les trous traversants (31A, 38) étant configurés de sorte qu'un corps rotatif (11) peut être inséré dans les deux trous traversants (31A, 38) ;

    une première portion d'ajustement fretté (28) est ménagée dans une portion de limite entre une surface circonférentielle externe (35a ; 88b, 89b) de la portion de mise en prise (35 ; 83) et une surface circonférentielle interne (33a ; 81a, 81b) de la portion évidée (33 ; 81), la surface circonférentielle interne (33a ; 81a, 81b) venant en contact avec la surface circonférentielle externe (35a ; 88b, 89b) de la portion de mise en prise (35 ; 83),

    caractérisée en ce que le second élément disque (27 ; 75) possède une portion en butée contre le premier élément disque (26 ; 73) dans la direction d'axe central (X) du disque (21 ; 71) et une portion formant un espace (41) entre le premier élément disque (26 ; 73) et le second élément disque (27 ; 75) dans la direction d'axe central (X) du disque (21 ; 71).


     
    2. Turbine selon la revendication 1,
    dans laquelle la portion de mise en prise (83) possède une pluralité de portions en gradins (88, 89) ayant différentes distances d'un axe central (O1) du disque (71) à la surface circonférentielle externe (88b, 89b) de la portion de mise en prise (83) dans la direction d'axe central (X) du disque (71), et
    une géométrie de la portion évidée (81) est une géométrie qui est configurée pour permettre à la portion évidée (81) d'être mise en prise avec la pluralité de portions en gradins (88, 89).
     
    3. Turbine selon la revendication 1 ou 2,
    dans laquelle la surface circonférentielle interne (33a ; 81a, 81b) de la portion évidée (33 ; 81) est une surface inclinée qui est inclinée dans une direction où un diamètre interne de la portion évidée (33 ; 81) est rétréci en allant d'une surface inférieure (33b ; 81c, 81Ba) de la portion évidée (33 ; 81) à un côté second élément disque, et
    la surface circonférentielle externe (35a ; 88b, 89b) de la portion de mise en prise (35 ; 83) est une surface inclinée qui est configurée pour amener une épaisseur de la portion de mise en prise (35 ; 83) à devenir plus petite à mesure qu'elle est séparée d'une surface de pointe (35b ; 88a, 89a) de la portion de mise en prise (35 ; 83), qui est disposée sur un côté premier élément disque, dans la direction d'axe central (X) du disque (21 ; 71).
     
    4. Turbine selon l'une quelconque des revendications 1 à 3,
    dans laquelle une clavette de positionnement (61) est ménagée à l'intérieur d'une portion où le premier élément disque (26) est venu en butée contre le second élément disque (27) dans la direction d'axe central (X) du disque (21).
     
    5. Machine rotative comprenant :

    la turbine selon l'une quelconque des revendications 1 à 4 ; et

    un corps rotatif (11) qui est configuré pour tourner autour d'un axe (O2) correspondant à un axe central (O1) du disque (21 ; 71) en tant qu'axe de rotation et auquel la turbine (16 ; 55 ; 60 ; 70 ; 90) est fixée,

    dans laquelle une seconde portion d'ajustement fretté (18) est ménagée dans une portion de limite entre une surface circonférentielle interne (31a) d'une portion du premier élément disque (26 ; 73), dans laquelle la portion évidée (33 ; 81) n'est pas formée, et une surface circonférentielle externe (11a) du corps rotatif (11).


     
    6. Machine rotative selon la revendication 5,
    dans laquelle une proportion d'ajustement fretté de la seconde portion d'ajustement fretté (18) est inférieure à une proportion d'ajustement fretté de la première portion d'ajustement fretté (28).
     
    7. Méthode de fabrication d'une turbine comprenant :

    une étape consistant à former un premier élément disque tubulaire (26 ; 73) ayant une portion évidée à géométrie annulaire (33 ; 81) en son sein ;

    une étape consistant à former une structure (67) dans laquelle un second élément disque (27 ; 75) ayant une portion de mise en prise à géométrie annulaire (35 ; 83) qui est configurée pour venir en prise avec le premier élément de disque (26 ; 73) en étant insérée dans la portion évidée (33 ; 81), et configure un disque avec le premier élément disque (26 ; 73), une pale (23) ménagée sur le second élément disque (27 ; 75), et un capot (24) qui est ménagé sur la pale, recouvre la pale (23) et définit un passage d'écoulement (25) entre le second élément disque (27 ; 75) et le capot (24) sont solidaires ; et

    une première étape d'ajustement fretté consistant à réaliser un ajustement fretté d'une portion de limite entre une surface circonférentielle externe (35a ; 88b, 89b) de la portion de mise en prise (35 ; 83) et une surface circonférentielle interne (33a ; 81a, 81b) de la portion évidée (33 ; 81) par l'insertion de la portion de mise en prise (35 ; 83) configurant la structure (67) dans la portion évidée (33 ; 81) et le chauffage du premier élément disque (26 ; 73) à partir d'un côté surface circonférentielle externe (31b) du premier élément disque (26 ; 73),

    dans lequel à la fois les premier et second éléments disque (26, 27 ; 73, 75) comprennent chacun un trou traversant (31A, 38), les trous traversants (31A, 38) étant configurés de sorte qu'un corps rotatif (11) peut être inséré dans les deux trous traversants (31A, 38) ;

    caractérisé en ce que dans l'étape consistant à former la structure (67), une longueur (L1, L2) de la portion de mise en prise (35 ; 83) dans la direction d'axe central (X) du disque (21 ; 71) est rendue plus grande qu'une profondeur (D1) de la portion évidée (33 ; 81) dans la direction d'axe central (X) du disque (21 ; 71) de sorte qu'une portion où le premier élément disque (26 ; 73) est en butée contre le second élément disque (27 ; 75) est formée et un espace (41) est formé entre le premier élément disque (26 ; 73) et le second élément disque (27 ; 75).


     
    8. Méthode de fabrication d'une machine rotative, comprenant :

    une étape consistant à préparer une turbine (16 ; 55 ; 60 ; 70 ; 90) fabriquée au travers de la méthode de fabrication d'une turbine (16 ; 55 ; 60 ; 70 ; 90) selon la revendication 7 ; et

    une seconde étape d'ajustement fretté consistant à réaliser un ajustement fretté d'une portion de limite entre une surface circonférentielle interne (31a) d'une portion du premier élément disque (26 ; 73), dans laquelle la portion évidée (33 ; 81) n'est pas formée, et une surface circonférentielle externe (11a) d'un corps rotatif (11) par le chauffage du premier élément disque (26 ; 73) à partir d'un côté surface circonférentielle externe (31b) de la portion dans laquelle la portion évidée (33 ; 81) n'est pas formée dans un état où le corps rotatif (11) est inséré dans la turbine (16 ; 55 ; 60 ; 70 ; 90).


     
    9. Méthode de fabrication d'une machine rotative selon la revendication 8,
    dans lequel une température de chauffage (T2) du premier élément disque (26 ; 73) dans la seconde étape d'ajustement fretté est inférieure à une température de chauffage (T1) du premier élément disque (26 ; 73) dans la première étape d'ajustement fretté.
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description