JP2005307892A - Rotary machine and its assembling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary machine capable of further reinforcing rigidity in the peripheral direction. <P>SOLUTION: A stationary blade ring (7) is composed of an outer ring (5), an inner ring (6), a plurality of outer side shroud rings (8) arranged on the inner peripheral side of the outer ring (5), an inner side shroud ring (9) arranged on the outer peripheral side of the inner ring (6), and a stationary blade ring between both rings (8) and (9). Two inner side shroud elements (13) arranged in the peripheral direction among a plurality of the inner side shroud elements (13) are connected by a connection element (25) connected in the peripheral direction. The connection element (25) is mounted in a mounting channel (27) formed in two inner side shroud elements (13) across the circumferential direction. Two inner side shroud elements (13) are connected in the peripheral direction to reinforce rigidity in the peripheral direction. A divided face between adjacent inner side shroud elements (13) is tightened by a connection force in the peripheral direction, in particular, a pressing-in force. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotating machine and an assembling method thereof, and more particularly, to a rotating machine constituting a stationary blade and a moving blade such as a compressor, a pump, and a turbine, and an assembling method thereof.

  A turbine is known as various power sources such as an electric drive source and a mechanical drive source. The turbine is provided as a rotating mechanical system configured in a turbine casing into which a gas flow and a steam flow are introduced. The rotating mechanical system is formed of an annular stationary blade row and an annular moving blade row. The annular stationary blade row is formed of an outer ring, an inner ring, and a fixed blade row that is sandwiched and supported between the inner and outer rings.

  For convenience of assembly, the annular stator blade row is divided into a semi-annular upper stator blade half ring and a semi-annular lower stator blade half ring. The upper stator blade half ring and the lower stator blade half ring are surface-bonded in a horizontal plane. In the cascade ring structure of the upper stator vane half ring and lower stator vane half ring that are joined and assembled in this manner, the radial assembly structure and the circumferential assembly structure are mechanically separated due to the existence of the joint region. It is difficult to construct a completely symmetrical structure. In order to avoid the deterioration of the rigid structure due to the asymmetry, various structural devices have been made.

  A technique for ensuring the coupling strength for coupling a large number of stationary blades to inner and outer rings in order to ensure the rigidity of the stationary blade row is known from Patent Document 1 described later. A technique for ensuring the joint rigidity of the joint surface area as described above is known from Patent Document 2 described later.

  The circumferential rigidity is strongly influenced by the mechanical connectivity between the numerous stator blade elements constituting the stator blade row and the inner and outer rings. Such mechanical connectivity includes circumferential connectivity between individual stator blade elements, radial connectivity of shrouds, which are a collection of stationary blade row elements formed as an annular structure between inner and outer rings, etc. It is defined by the factors. In particular, the presence of a dividing surface that divides the shroud in the radial direction is an important cause of a decrease in circumferential rigidity. The reduction in circumferential rigidity leads to an increase in the fall force that causes the stationary blade row to fall downstream due to pressure load during turbine operation. Such an increase cannot completely eliminate the possibility that a stationary blade row that falls downstream contacts the downstream blade or rotor disk, and as a result, induces a serious accident. Although welding techniques are effective for enhancing circumferential rigidity, there are other problems with welding.

  There is a need for further enhancement of circumferential rigidity. It is important not to use welding techniques.

Japanese Utility Model Publication No.59-102901 JP-A-9-112204

The subject of this invention is providing the rotary machine which reinforces circumferential rigidity further, and its assembling method.
Another object of the present invention is to provide a rotating machine and a method of assembling the rotating machine that further simply enhances the circumferential rigidity.

  The rotating machine according to the present invention includes a plurality of blade rings (3) arranged in the axial direction and a plurality of stationary blade rings (7) arranged between the blade rings (3) and arranged in the axial direction (Z). Has been. One of the stator blade rings (7) includes an outer ring (5), an inner ring (6), and an outer shroud ring arranged on the inner peripheral side of the outer ring (5) and having a plurality of outer shroud elements (12) arranged in the circumferential direction. (8), an inner shroud ring (9) arranged on the outer peripheral side of the inner ring (6) and arranged with a plurality of inner shroud elements (13) in the circumferential direction, an outer shroud ring (8) and an inner shroud ring (9). A stator blade ring (7) arranged between the plurality of stator blade elements (14) arranged in the circumferential direction and two inner shroud elements (13) arranged in the circumferential direction among the plurality of inner shroud elements (13) in the circumferential direction It is comprised from the coupling | bonding element (25) couple | bonded with. The coupling element (25) is mounted in a mounting groove (27) formed in the circumferential direction on the two inner shroud elements (13).

  The inner shroud elements (13) adjacent to each other in the circumferential direction are coupled in the circumferential direction, and the rigidity in the circumferential direction is enhanced. The dividing surface between adjacent inner shroud elements (13) is tightened by a circumferential coupling force, in particular a pressure input. It is particularly important that the coupling element is arranged downstream of the inner shroud element because the downstream part that receives the fluid pressure is tightened and constrained in the circumferential direction. The vane ring (7) is configured as a combination of two half rings. Increasing the circumferential stiffness of the half rings can enhance the circumferential stiffness of the coupling region of the two half rings.

  The coupling element (25) is driven radially into the mounting groove (27) to stiffen the two inner shroud elements in the circumferential direction. In this case, the coupling element (25) is confined in the radial direction by the inner ring (6) and prevented from coming out. The closed annular coupling element (25) mounted in the closed mounting groove (27) is mechanically strong. Since it is possible to attach the coupling element (25) in the axial direction after assembling all or half of the stator blade ring (7), the degree of freedom of the assembly process can be expanded.

  The mounting groove (27) is formed as a partial annular hole extending in the circumferential direction. In this case, the coupling element (25) frictionally fits the mounting groove (27), thereby stiffening the two inner shroud elements (13) in the circumferential direction.

  The circumferential stiffness enhancement of the outer shroud elements adjacent in the circumferential direction is the same as the circumferential stiffness enhancement of the inner shroud elements. In that case, the outer coupling element is pressed in the centripetal direction. Axial insertion is the same as the insertion method of the inner coupling element.

The method of assembling a rotating machine according to the present invention comprises the following set of steps:
The process of manufacturing the outer ring half ring and the inner ring half ring by machining, sequentially inserting the prescribed number of outer shroud elements into the inner ring side of the outer ring half ring, and the prescribed number of inner sides on the outer ring side of the inner ring half ring. The shroud elements are sequentially inserted, and the connecting element straddling two stationary blade elements adjacent in the circumferential direction is mounted. In such a manufacturing process, the flexibility of the manufacturing process can be expanded by attaching the coupling element in the axial direction after the step of sequentially inserting the inner shroud elements.

  The rotating machine according to the present invention and the assembling method thereof can further enhance the circumferential rigidity, and the strengthening is simple in terms of mechanical structure.

  Preferred embodiments of the rotating machine according to the present invention will be described in detail with reference to the drawings. As shown schematically in FIG. 1, the main structure of the turbine is an axle 2 that is supported by penetrating through the turbine casing 1, and a motion that is fixed to the axle on the peripheral surface side of the axle 2 and arranged in multiple stages. A blade ring (semi-ring) 3 and a stationary blade structure ring (semi-ring) 4 disposed between axially adjacent blade rings 3 are configured. The main steam is introduced into the passenger compartment 1 from the main steam inlet A. The direction of the axial flow of the main steam is adjusted by the stationary blade structure ring 4 and injected toward the moving blade ring 3 on the downstream side. The rotor blade ring 3 rotates by receiving a circumferential component force from the axial flow steam whose flow direction is adjusted. The circumferential component force is given to the rotor blade ring 3 in multiple stages between the upstream side and the downstream side.

  FIG. 2 shows a single stage stator vane structure ring 4. The stationary blade structure ring 4 is formed of an outer ring 5, an inner ring 6, and a stationary blade ring 7. The stationary blade ring 7 is arranged in an annular space between the outer ring 5 and the inner ring 6. The vane ring 7 is formed by an outer shroud 8, an inner shroud 9, and an annular vane element row 11. The outer shroud 8 is a combined set of a large number (for example, several tens) of outer shroud elements 12 that are divided in the circumferential direction and arranged in the circumferential direction. The inner shroud 9 is a combined set of a number of inner shroud elements 13 that are divided in the circumferential direction and arranged in the circumferential direction. The annular vane element row 11 is a combined set of a large number of vane elements 14 divided in the circumferential direction and arranged in the circumferential direction. A number of outer shroud elements 12 are sequentially inserted along an annular groove 15 formed on the inner circumferential surface side of the outer ring 5 along a semicircular line, and adjacent outer shroud elements 12 abut on the semicircular circumference. Join face-to-face. A large number of inner shroud elements 13 are sequentially inserted along an annular groove (or annular projection) 16 formed on the outer peripheral surface side of the inner ring 6 along the semicircular line, and adjacent inner shroud elements 13 are abutted halfway. Join face-to-face on the circumference. A number of vane elements 14 are inserted between the outer shroud 8 and the inner shroud 9 so arranged.

  FIG. 3 shows three-dimensional shapes of a part of the outer shroud element 12 of the outer shroud 8, a part of the inner shroud element 13 of the inner shroud 9, and a part of the stator blade elements 14 of the annular stator element array 11. These three-dimensional arrangement relationships are shown. The outer shroud element 12 and the inner shroud element 13 that are adjacent to each other in the circumferential direction respectively have a rotation direction front side dividing surface 17 and a rotation direction rear side dividing surface 18 that face each other in the circumferential direction. Each of the rotation direction front side dividing surface 17 and the rotation direction rear side dividing surface 18 is formed of two radiation surface portions of the radiation surface including the rotation axis and a slope portion 19 which is inclined with respect to the radiation surface. Has been. The dividing line of the outer shroud element 12 by the slope portion 19 and the dividing line of the inner shroud element 13 by the slope portion 19 appear on the cylindrical surface (circumferential surface) orthogonal to the radial direction or the radial direction R. It is impossible to completely eliminate the gap 21 between the rotation direction front side dividing surface 17 and the rotation direction rear side dividing surface 18, and for this reason, the circumferential rigidity is ideally determined only by the machining accuracy. I can't get it. The outer shroud element 12, the inner shroud element 13, and the stationary blade element 14 each have an appropriate thickness in the axial direction Z. The three-dimensional shape of the inner shroud element 13 is substantially the same as the three-dimensional shape of the outer shroud element 12 except for the size. The front and rear surfaces of the stationary blade element 14 in the circumferential direction P are inclined with respect to the radiation surface and bent to be curved. A set of two stationary blade elements 14 adjacent to each other in the circumferential direction constitutes a nozzle that allows steam to pass through the steam injection flow path 22 therebetween.

  FIG. 4 shows a preferred embodiment of the circumferential rigidity enhancing structure for a rotating machine according to the present invention. FIG. 4 is represented as an exploded view of the outer shroud 8 or the inner shroud 9 in the R view. This embodiment is also applied to the outer shroud 8. The definition of the axial flow direction is important. An axial flow (example: vapor flow) direction is defined as a negative Z direction that is opposite to the Z direction indicated by an arrow in the figure. Downstream region (or exit side region) of the divided boundary region 23 including two divided broken lines (hereinafter referred to as dividing lines) where the dividing surfaces 17 and 18 appear on the inner peripheral surface (side surface) of the inner shroud element 13. At 24, the restraining piece 25 is inserted and press-fitted across two adjacent inner shroud elements 13. The restraint piece 25 of this embodiment is shaped like a portal. Each of the rotation direction front side division surface 17 and the rotation direction rear side division surface 18 is substantially parallel to the radiation surface including the axial center line. The dividing line of the downstream region 24 is hereinafter referred to as a downstream virtual dividing line 26. The downstream virtual dividing line 26 extends in the Z direction.

  The restraining piece 25 is embedded in a restraining piece press-fitting groove 27 extending in the Z direction. The restraining piece press-fitting groove 27 is opened on the inner peripheral surface side (exit side defined as the downstream side of the airflow) DS. The constraining piece press-fitting groove 27 is continuous with the circumferential groove portion 28 extending in the circumferential direction P across the adjacent inner shroud elements 13 and one circumferential side of the circumferential groove portion 28 in the radial direction. One side radial groove portion 29 extending in the inner shroud element 13 and the other side radiation extending continuously in the other circumferential side of the circumferential groove portion 28 and extending radially in the inner shroud element 13 on the other side. The direction groove portion 31 is formed. The restraining piece 25 includes a circumferential piece portion 32 that corresponds in position to the circumferential groove portion 28, a one-side radial piece portion 33 that corresponds in position to the one-side radial groove portion 29, and the other-side radiation. The other side radial piece portion 34 corresponding to the directional groove portion 31 is integrally formed. The restraining piece 25 formed of a high-rigidity metal is driven into the restraining piece press-fitting groove 27 in the axial direction and is press-fitted between two adjacent inner shroud elements 13.

  The constraining piece 25 can connect (couple) the outer shroud elements 12 or the inner shroud elements 13 adjacent to each other in a ring shape in a semi-annular manner to form an integral connection structure, and increase the rigidity of the half ring structure. it can. The row of restraining pieces 25 is arranged on the outlet side (downstream side) of the outer shroud 8 or the inner shroud 9 and is pushed down by the airflow 35 flowing from the upstream side to the downstream side (in the axial direction Z). The resistance force is increased by increasing the rigidity of the annular stator blade element row 11 against the pushing force (pitching force). The airflow 35 flowing in the annular stator element row 11 is not parallel to the axial direction Z but obliquely directed to the axial direction Z, and the circumferential stationary component pressure is applied to the annular stator element row 11. Works. Since the restraint piece 25 enhances the circumferential rigidity of the annular stationary blade element row 11 on the downstream side, it is possible to enhance the resistance against the pushing force described above. In such a side-mounted configuration in which the restraining piece 25 can be driven in the axial direction, the restraining piece 25 can be attached to the outer shroud element 12 after the annular stator vane element row 11 is assembled to the outer shroud 8. Thus, the degree of freedom of assembly work is expanded. The gate-shaped restraint piece 25 is easy to process.

  FIG. 5 shows another preferred embodiment of the circumferential rigidity enhancing structure for a rotating machine according to the present invention. The restraint piece 25 of this embodiment is shaped into a closed rectangular ring. A closed ring such as a rectangular shape is less likely to be deformed and has a stronger restraining force than the portal shape of the above-described form. The restraint piece 25 of this embodiment is formed by integrally closing two circumferential piece portions 32 'and radial piece portions 33' on both sides extending in the axial direction. The constraining piece press-fit groove 27 into which such a rectangular ring can be inserted is formed to extend in the radial direction in the adjacent outer shroud element 12 or inner shroud element 13. The circumferential piece portion 32 ′ is driven in a radial direction across the circumferential direction P in two adjacent outer shroud elements 12 or inner shroud elements 13. An end surface orthogonal to the radial direction R of the restraining piece 25 is joined to the inner peripheral surface of the outer ring 5 or the inner peripheral surface of the inner ring 6. The inner ring 6 and the outer ring 5 have a lid function with respect to the restraining piece 25 and can prevent the restraining piece 25 from falling off. The significance of the restraint piece 25 being arranged on the outlet side is as described above.

  FIG. 6 shows still another preferred embodiment of the circumferential rigidity enhancing structure for a rotating machine according to the present invention. FIG. 6 is a developed view in Z view of the outer shroud 8, the annular stator blade element row 11, and the inner shroud 9. The gate-shaped first restraining piece 25 -O is joined to the downstream end face of the outer shroud 8 across the downstream virtual dividing line 26 of two adjacent outer shroud elements 12 of the outer shroud 8. The gate-shaped second restraint piece 25 -I is joined to the downstream end face of the inner shroud 9 across the downstream virtual dividing line 26 of two adjacent inner shroud elements 13 of the inner shroud 9. The effect of preventing the falling off of the restraining pieces 25-O, I of this embodiment of the end face mounting type is the same as that of the restraining piece 25 of the form described above in FIG.

  FIG. 7 shows still another preferred embodiment of the circumferential rigidity enhancing structure for a rotating machine according to the present invention. FIG. 7 is a developed view in Z view of the outer shroud 8, the annular stator blade element row 11, and the inner shroud 9. The rectangular ring-shaped first restraining piece 25 -O is joined to the downstream end face of the outer shroud 8 across the downstream virtual dividing line 26 of two adjacent outer shroud elements 12 of the outer shroud 8. The rectangular ring-shaped second restraint piece 25 -I is joined to the downstream end face of the inner shroud 9 across the downstream virtual dividing line 26 of the two inner shroud elements 13 adjacent to each other in the inner shroud 9. The effect of enlarging the degree of freedom in assembling the restraint pieces 25-O and I of the side-mounted type in this embodiment is the same as that of the restraint piece 25 in the form described above in FIG.

  FIG. 8 shows still another preferred embodiment of the circumferential rigidity enhancing structure for a rotating machine according to the present invention. The restraint piece 25 of this embodiment is replaced with the restraint piece 25 of FIG. The constraining piece 25 of this embodiment is formed as a rectangular plate having two holes, and is embedded in the end face of the outer shroud element 12 or the inner shroud element 13. It is attached. This end face coupling type has the above-described drop-off preventing effect. The restraint piece 25 of FIG. 7 can be replaced with the restraint piece 25 of FIG.

  FIG. 9 shows still another preferred embodiment of the circumferential rigidity enhancing structure for a rotating machine according to the present invention. An axial orthogonal dividing surface 37 having a component orthogonal to or orthogonal to the axial direction Z and extending in the axial direction is added to the dividing surface 26 that appears in the outer shroud element 12. Two adjacent outer shroud elements 12 are joined in a face-joint manner by a bolt 38 having a screw axis perpendicular to the axially orthogonal dividing surface 37. The bolt hole is formed instead of the restraining piece press-fitting groove 27. The point that the binding site is arranged on the outlet side is as described above. Thus, this form which couple | bonds the dividing surfaces may be applied also to the inner shroud 9. FIG. The side-fixing type coupling operation of this embodiment is possible after the assembly of the entire wing, and has the effect of expanding the degree of freedom of the operations described above.

  In principle, the stator blade structure ring is divided into two. Reinforcing the circumferential rigidity only in the vicinity of the joint surface of the two rings relies on a different idea from the present invention. As is well known for bridge piers and dam arch structures, increasing the circumferential stiffness of the central portion of the arch enhances the circumferential stiffness of the end of the arch. The restraint piece 25 of the present invention is applied in the vicinity of the joining surface of the semi-annular inner and outer shrouds. By connecting the outermost shroud element 12 and the inner shroud element 13 at the uppermost end of the lower half ring to the outermost shroud element 12 and the inner shroud element 13 at the lowermost end of the upper half ring, respectively, by the constraining pieces 25. The circumferential rigidity of the joining region between the half rings can be enhanced. By forming the restraining piece 25 with a particularly high rigidity in the joining region, and by specifically increasing the size, the rigidity of the entire ring can be equalized.

Other forms of implementation:
A partial annular pin extending in the circumferential direction is embedded across the circumferential joining surface region of the adjacent outer shroud element 12 or inner shroud element 13, and circumferential rigidity is increased by frictional coupling between the pin and the outer shroud element 12 or inner shroud element 13. That is meaningful. In that case, the cross section of the annular pin is not limited to a circular shape, and it is desirable to form a friction surface having a large peripheral surface area such as a star shape or a gear shape. Insertion by shrink fitting is effective.

The assembly or assembly of the half ring of FIG. 1 includes the following steps.
(1) Manufacturing half ring of outer ring 5 and half ring of inner ring 6 by machining (2) Inserting a predetermined number of outer shroud elements 12 sequentially into the inner circumference side of the half ring of outer ring 5 (3) Inner ring (5) After step (2) and step (3) or simultaneously with step (2) and step (3) Mounting a predetermined number of vane elements between the outer shroud element and the inner shroud element (5) mounting a coupling element 25 straddling two circumferentially adjacent vane elements, wherein step (5) If the coupling element (25) is inserted axially, step (4) can be carried out after step (3). In both cases where the coupling element 25 is mounted in the radial direction and when the coupling element 25 is mounted in the axial direction, the coupling element 25 does not slip out in the centripetal direction by the inner ring 6. Such an assembling sequence can also be applied when the outer shroud is coupled by the coupling element.

FIG. 1 is a sectional view showing a preferred embodiment of a rotating machine according to the present invention. FIG. 2 is an oblique projection showing the shroud. FIG. 3 is an oblique projection showing the stator blade ring. FIG. 4 is a developed view showing a preferred form of circumferential rigidity enhancement. FIG. 5 is a development view showing another preferred form of circumferential rigidity enhancement. FIG. 6 is a developed view showing still another preferred form of circumferential rigidity enhancement. FIG. 7 is a developed view showing still another preferred form of circumferential rigidity enhancement. FIG. 8 is a developed view showing still another preferred form of circumferential rigidity enhancement. FIG. 9 is a development view showing still another preferred form of circumferential rigidity enhancement.

Explanation of symbols

3 ... Rotor ring 5 ... Outer ring 6 ... Inner ring 7 ... Stator blade ring 8 ... Outer shroud ring 9 ... Inner shroud ring 12 ... Outer shroud element 13 ... Inner shroud element 14 ... Stator blade element 25 ... Coupling element 27 ... Mounting groove Z ... Axial direction

Claims (14)

A plurality of blade rings arranged in the axial direction;
A plurality of stationary blade rings arranged between the rotor blade rings and arranged in the axial direction;
One of the stator blade rings is
Outer ring,
Inner ring,
An outer shroud ring arranged on the inner circumferential side of the outer ring and in which a plurality of outer shroud elements are arranged in the circumferential direction;
An inner shroud ring arranged on the outer peripheral side of the inner ring and in which a plurality of inner shroud elements are arranged in the circumferential direction;
A stationary blade row ring arranged between the outer shroud ring and the inner shroud ring and in which a plurality of stationary blade elements are arranged in the circumferential direction;
A coupling element that couples two inner shroud elements arranged in the circumferential direction among the plurality of inner shroud elements in the circumferential direction;
The coupling element is mounted in a mounting groove formed in a circumferential direction on the two inner shroud elements. The rotating machine according to claim 1, wherein the coupling element is disposed downstream of the inner shroud element. The rotating machine according to claim 1, wherein the coupling element is driven into the mounting groove in a radial direction to rigidize the two inner shroud elements in the circumferential direction. The rotary machine according to claim 1, wherein the coupling element is axially driven into the mounting groove to rigidize the two inner shroud elements in the circumferential direction. The rotary machine according to claim 1, wherein the mounting groove is formed in a closed ring shape. The rotating machine according to claim 1, wherein the mounting groove is formed as a partial annular hole extending in a circumferential direction, and the coupling element frictionally fits the mounting groove to stiffen the two inner shroud elements in the circumferential direction. An outer coupling element that couples two circumferential outer shroud elements of the plurality of outer shroud elements in the circumferential direction;
The rotating machine according to claim 1, wherein the outer coupling element is mounted in an outer mounting groove formed in a circumferential direction on the two outer shroud elements. The rotating machine according to claim 7, wherein the outer coupling element is disposed downstream of the stationary blade element. The rotating machine according to claim 7, wherein the outer coupling element is driven into the outer mounting groove in a centripetal direction to stiffen the two outer shroud elements in the circumferential direction. The rotating machine according to claim 7, wherein the outer coupling element is axially driven into the outer mounting groove to stiffen the two outer shroud elements in the circumferential direction. The rotating machine according to claim 1, wherein the outer mounting groove is formed in a closed ring shape. 8. The outer mounting groove is formed as a partial annular hole extending in the circumferential direction, and the outer coupling element frictionally fits the outer mounting groove to stiffen the two outer shroud elements in the circumferential direction. machine. The following set of steps:
Manufacturing the outer ring half ring and the inner ring half ring by machining;
Sequentially inserting a specified number of outer shroud elements into the inner ring side of the outer ring half ring;
Sequentially inserting a specified number of inner shroud elements into the outer ring side of the inner ring half ring,
A method of assembling a rotating machine comprising the step of mounting a coupling element straddling two stationary blade elements adjacent in the circumferential direction. The method of assembling a rotating machine according to claim 13, wherein the attaching step is executed after the step of sequentially inserting the inner shroud elements, and in the attaching step, the coupling element is inserted in the axial direction.

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