JP5680002B2 - Turbine blades and steam turbines - Google Patents

Description

  Embodiments of the present invention relate to a turbine rotor blade and a steam turbine including a joint (hereinafter referred to as “segment”) attached to a blade tip, for example.

  In general, in a turbine blade, in order to suppress vibration generated during operation, a blade binding structure that combines a plurality of blades with segments provided between the blade tip portions to form a so-called all-round blade group. Is used.

  In this all-around one-group blade spelling structure, for example, two tenon holes provided substantially in the turbine rotor circumferential direction at the tip of the blade and two segment tenon parts provided in the segment (hereinafter simply referred to as “tenon part”); As a result, the turbine rotor blades are assembled (see, for example, Patent Document 1). In such a turbine rotor blade, in order to cope with deformation such as torsional return of the rotor blade during operation, the tenon portion may be fitted into the tenon hole without caulking.

JP 2003-214113 A

  However, in the above-described prior art, vibrations are constantly generated in the turbine rotor blades during operation, and the stress due to the pressing of the vibration acts strongly on the contact end of the tenon portion and the tenon hole, and this is the contact end of the tenon hole. There is a problem that a crack caused by this stress occurs in the curved portion.

  The present invention has been made to solve such a problem, and provides a turbine rotor blade and a steam turbine capable of improving damage generated in a fitting portion between a blade tip portion and a segment of the turbine rotor blade. For the purpose.

In order to solve the above-described problem, the turbine rotor blade of the present invention has a back portion and an abdominal portion twisted about a first axis K substantially perpendicular to the rotating shaft of the turbine, and a cord different from the direction of the first axis K. A first blade effective portion having a first blade top portion having a direction, and side surfaces corresponding to each other along a surface arranged at the first blade top portion and defined by the direction of the first axis K and the cord direction. A first blade tip portion having each, a second blade having a cord direction different from the direction of the second axis K, having a back portion and an abdominal portion twisted about a second axis K substantially perpendicular to the rotation axis of the turbine. A second blade effective portion having a top portion, and a second blade tip disposed on the second blade top portion and having side surfaces corresponding to each other along a plane defined by the direction of the second axis K and the cord direction And the side surface of the first wing effective portion A first tenon hole having at least a straight line portion extending in the cord direction of the first blade tip and facing each other, and a curved portion connected to the straight line portion, and the second blade effective portion A second tenon hole having a straight line portion penetrating through the side surfaces of the second wing tip portion and extending along the cord direction of the second blade tip portion and facing each other, and a curved portion connected to the straight line portion, 1, is arranged between the second wing tip, organic and a first tenon portion of the convex shape to be inserted into the first tenon hole, a second tenon portion having a convex shape to be inserted into the second tenon hole, the And at least one of the first and second tenon portions includes a segment that is movably fitted to the first and second tenon holes, and the first and second tenon portions move. wherein the can fitted first, at least the curved portion of the second tenon hole Zureka is characterized by having a relief portion that protrudes from the width between the straight portion.

  A steam turbine according to the present invention includes the turbine blade described above.

  ADVANTAGE OF THE INVENTION According to this invention, the damage which generate | occur | produces in the fitting part of the blade tip part and segment of a turbine bucket can be improved.

It is a perspective view which shows the state which inserted some rotor blades in the assembly of the turbine rotor blade of embodiment of this invention. It is sectional drawing which shows the cross section of the blade | wing effective part of the blade | wing front-end | tip part side shown in FIG. It is a DD arrow line view of Embodiment 1 which shows the upper surface of FIG. FIG. 4 is an enlarged side view showing an enlarged side surface of the blade tip portion side of the moving blade shown in FIG. 3 as viewed from the blade side. It is the enlarged view to which the 1st tenon hole and the 1st tenon part which were shown in FIG. 4 were expanded. It is an enlarged view which shows the curve part of the tenon part shown in FIG. It is the DD arrow line view of Embodiment 2 which shows the upper surface of FIG. FIG. 8 is an enlarged side view showing an enlarged side surface of the blade tip portion side of the moving blade shown in FIG. 7 viewed from the blade side. It is the enlarged view to which the tenon hole and tenon part which were shown in FIG. 8 were expanded. It is a DD arrow line view of Embodiment 3 which shows the upper surface of FIG. FIG. 11 is an enlarged side view showing an enlarged side surface of the blade tip portion side of the moving blade shown in FIG. 10 as viewed from the blade side. It is the enlarged view to which the tenon hole and tenon part which were shown in FIG. 11 were expanded. It is the enlarged view to which the other tenon hole and other tenon part which were shown in FIG. 11 were expanded. It is an enlarged view which shows the curve part of the tenon hole shown in FIG. It is an enlarged view of the application example which shows the curve part of the tenon hole shown in FIG. It is an enlarged view of the other application example which shows the curve part of the tenon hole shown in FIG. It is a DD arrow line view of Embodiment 4 which shows the upper surface of FIG. FIG. 18 is an enlarged side view showing an enlarged side surface on a blade tip portion side of the moving blade shown in FIG. 17 as viewed from the blade belly side. It is the enlarged view which expanded another example of the tenon hole, and the tenon part.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a state in which some of the blades are inserted in the assembly of the turbine blade 1 according to the embodiment of the present invention.

  As shown in FIG. 1, the turbine rotor blade 1 includes a plurality of rotor blades 10. These moving blades 10 are implanted in a turbine wheel implantation portion 2 of a turbine rotor (not shown) to form an annular blade row. Steam flows into the blade row from the inlet side in the direction of the rotation axis of the turbine rotor (arrow direction A in the drawing), passes between the rotor blades 10, and flows out from the outlet side. The turbine blade 1 is rotated by the passage of the steam. In FIG. 1, only some of the moving blades 10 that are implanted in the circumferential direction of the turbine rotor (the arrow direction B on the paper surface) are shown.

  In this embodiment, the turbine rotor blade 1 moves in the arrow direction B, that is, the rotation of the turbine rotor with respect to the flow of steam from the inlet direction in the arrow direction A, that is, in the upper right direction on the paper, to the outlet side in the lower left direction. It is assumed that it rotates in the left direction (counterclockwise) on the paper surface about an axis (not shown).

  The moving blade 10 has a blade effective portion 11, a blade tip portion 12, and a blade implantation portion 13. The blade effective portion 11 is formed in the central portion of the moving blade 10. The blade tip 12 is formed at the blade top, which is the tip of the blade effective portion 11 (details will be described later). The blade implantation portion 13 is a fork-shaped blade implantation portion that is formed at the blade root portion of the blade effective portion 11 and fits with a groove of the turbine wheel implantation portion 2, for example. Note that the blade effective portion 11, the blade tip portion 12, and the blade implantation portion 13 of each rotor blade 10 are configured in the same shape, and between the blade tip portions 12, 12 of the adjacent rotor blades 10, 10. The segments 20 are respectively attached.

In this embodiment, for convenience, the blade effective portion 11 and the blade tip portion 12 of the moving blade 10 on the front side in the rotation direction among the adjacent blades 10 are defined as the first blade effective portion and the first blade tip portion, and the rotation direction. The blade effective portion 11 and the blade tip portion 12 of the rear moving blade 10 are defined as a second blade effective portion and a second blade tip portion.
Note that, for example, a sleeve 14 that connects the blade effective portions 11 to each other is disposed at the center of the blade effective portion 11 of each rotor blade 10.

  FIG. 2 is a sectional view showing a section of the blade effective portion 11 on the blade top side shown in FIG. Here, the hatched portion (solid line portion) in the figure is the blade tip 12 side of the blade effective portion 11, the one-dot chain line portion is near the center of the blade effective portion 11, and the two-dot chain line portion is the blade effective portion 11. Each blade root side is shown.

As shown in FIG. 2, each blade effective portion 11 has a substantially streamlined cross section (see the hatched portion on the paper), and has a blade back 11a indicating the back of the blade and a blade belly 11b indicating the abdomen of the blade. .
The blade back 11a is formed such that the steam outlet side is curved in a convex shape. The wing antinode 11b is formed by bending the steam inlet side into a concave shape.
Adjacent blade effective portions 11 pass steam flowing from the inlet side in the arrow direction A through a gap formed between the blade back 11a and the blade belly 11b.

  In the blade effective portion 11, when viewed from the upper surface of the blade tip portion 12 (see the C direction shown in FIG. 1), the blade top portion (the hatched portion on the paper surface) is included in the shape of the blade tip portion 12. (See FIG. 3 described later). The blade top portion has a longitudinal direction (code direction H) along a direction (substantially perpendicular direction) different from the axis K (see a central axis K in FIG. 4 described later).

  The blade effective portion 11 is formed in a slightly twisted shape with the cross section becoming thicker from the blade top side toward the blade root portion (blade implanting portion 13) side. That is, the blade effective portion 11 is formed in a twisted shape about a first axis K (a center axis K in FIG. 4 described later) that is substantially perpendicular to the rotation axis of a turbine rotor (not shown).

  The blade effective part 11 having such a configuration rotates a turbine rotor (not shown) in an arrow direction B (upward on the paper surface) by receiving steam flowing in from the arrow direction A (rightward on the paper surface). Due to the centrifugal force associated with the rotation of the turbine rotor, the blade effective portion 11 is twisted back about the axis K in the clockwise direction on the paper.

  Here, of the blade effective portions 11 of the adjacent moving blades 10, the blade top portion included in the first blade effective portion is the first blade top portion, the axis K is the first axis K, and the blade top portion included in the second blade effective portion. Is the second blade tip, and its axis K is the second axis K.

  3 is a DD arrow view showing the upper surface of FIG. FIG. 4 is an enlarged side view showing an enlarged side surface on the blade tip 12 side of the moving blade 10 shown in FIG. FIG. 3 shows the time when the turbine rotor is stopped, and FIG. 4 shows the time when the turbine rotor is in operation. Moreover, in the moving blade 10 of the following figure, let the front side of the rotation direction B of a turbine rotor be a front edge side, and let the rear side of the rotation direction B of a turbine rotor be a rear edge side.

  As shown in FIGS. 3 and 4, a blade tip portion 12 is integrally formed at the blade top portion of the blade effective portion 11, and the blade top portion of the blade effective portion 11 is formed on the lower surface of the blade tip portion 12. It is formed so as to be included in the shape. As shown in FIG. 4, the blade tip 12 is formed in a substantially rectangular parallelepiped having a longitudinal direction along a direction different from the direction of the central axis K, that is, the cord direction of the blade top portion of the blade effective portion 11 as a longitudinal direction. Has been. The length of the blade tip 12 in the longitudinal direction is configured to be approximately twice the length of the segment 20 in the longitudinal direction.

  The longitudinal direction of the blade tip portion 12 changes in a direction different from that at the time of stoppage due to torsional return during operation of the turbine rotor with respect to the steam inlet direction (arrow direction A in FIG. 3). That is, in this embodiment, the angle formed by the longitudinal direction (code direction) of the blade tip 12 and the steam inlet direction when the turbine rotor is stopped is set to an acute angle, for example, but it is caused by twisting back during operation. It is configured to change to an acute angle smaller than the aforementioned stop angle.

Hereinafter, the first blade tip 12 and the second blade tip 12 will be described separately.
As shown in FIGS. 3 and 4, the first blade tip 12 is disposed at the top of the first blade and corresponds to the side surfaces 12c corresponding to each other along a surface defined by the direction of the first axis K and the cord direction. 12d. That is, the side surface 12c is a side surface disposed on the front edge side in the rotation direction B of the turbine rotor and on the blade back 11a side. The side surface 12d is a rear surface of the side surface 12c, and is a side surface disposed on the rear edge side of the rotation direction B of the turbine rotor and on the blade antinode 11b side.

The first blade tip 12 is provided with tenon holes 12a and 12b penetrating a side surface (side surface on the blade back 11a side) 12c and a side surface (side surface on the blade belly 11b side) 12d.
The tenon hole (third tenon hole) 12a penetrates the side surfaces 12c and 12d, has an opening in each, and has four straight portions 12a1 to 12a4 and four curved portions 12a5 to connect to these straight portions 12a1 to 12a4. 12a8.

  Two straight portions 12a1 and 12a2 of these straight portions 12a1 to 12a4 are along the cord direction (longitudinal direction) of the first blade tip 12 and are opposed to each other. The other two straight portions 12a3 and 12a4 are opposed to each other along a direction (short direction) different from the cord direction of the first blade tip portion 12.

  The tenon hole (first tenon hole) 12b has openings on the side surfaces 12c and 12d, and includes four straight portions 12b1 to 12b4 and four curved portions 12b5 to 12b8 connected to the straight portions 12b1 to 12b4. Have.

  Two straight portions 12b1 and 12b2 of these straight portions 12b1 to 12b4 are along the cord direction of the first blade tip portion 12 and opposed to each other. The other two straight portions 12b3 and 12b4 are opposed to each other along a direction (short direction) different from the cord direction of the first blade tip portion 12.

  As shown in FIG. 4, these tenon holes 12 a and 12 b are arranged side by side in the longitudinal direction along the cord direction of the first blade tip 12, for example, and are formed on the paper surface around the central axis K of the blade tip 12. They are provided at symmetrical positions. Of the tenon holes 12a and 12b, the tenon hole 12a is provided on the front edge side which is the front side in the rotational direction B of the turbine rotor, and the tenon hole 12b is provided on the rear edge side which is the rear side in the rotational direction B of the turbine rotor. .

  The tenon holes 12a and 12b are formed so that the cord direction of the first blade tip 12 is the longitudinal direction of the tenon hole. The tenon holes 12a, 12b are formed from an R curved portion formed in a circular arc shape having a quarter of the same circumferential length and straight portions formed on the top, bottom, left, and right of the paper so as to connect the curved portions. It is configured. Of these curved portions, the curved portion 12b5 has a different shape from the other curved portions, and will be described in detail later.

  As described above, the blade tip 12 of each rotor blade 10 is configured in the same shape, and the blade tip 12 of the rotor blade 10 adjacent to a certain first blade tip 12 is used as a second blade tip for convenience. Part 12 is assumed. Below, the difference between the second blade tip 12 and the first blade tip 12 will be described.

  As shown in FIG. 3, the second blade tip 12 has a shape twisted about a second axis (similar to the central axis K) substantially perpendicular to the rotation axis of the turbine rotor, and the second axis K A second blade top portion having a cord direction along a longitudinal direction different from the first direction.

  The second blade tip 12 has side surfaces 12c and 12d corresponding to each other along a surface defined by the direction of the second axis K and the longitudinal direction. The second blade tip 12 is provided with tenon holes 12a (second tenon holes) and 12b penetrating through a side surface (side surface on the blade back 11a side) 12c and a side surface (side surface on the blade belly 11b side) 12d. ing. The configurations of the side surfaces 12c and 12d, the second tenon hole 12a, and the tenon hole 12b are the same as those of the side surfaces 12c and 12d, the third tenon hole 12a, and the first tenon hole 12b of the first blade tip portion 12, and thus are omitted.

  As shown in FIG. 3, the segments 20 are arranged between the blade tip portions 12, 12 of the adjacent moving blades 10, 10, and are connected to the blade tip portions 12 of the moving blades 10, so-called all-round group blades. It consists of a wing spell structure. The segment 20 has an upper surface formed in a substantially diamond shape whose longitudinal direction is the longitudinal direction of the blade tip 12.

  The segment 20 is disposed between the first and second blade tip portions 12 and 12 described above, and is inserted into the first tenon hole 12b of the first blade tip portion 12 and the second blade tip portion. And a second tenon portion 20a inserted into the 12 second tenon holes 12a.

  The second tenon portion 20a is disposed so as to protrude from one side surface in the longitudinal direction of the segment 20, and is inserted into the second tenon hole 12a of the second blade tip portion 12 on the trailing edge side in the rotational direction B of the turbine rotor. Mated. The head portion 20c of the second tenon portion 20a passes through the second tenon hole 12a and is then caulked and fixed to the second blade tip portion 12.

The first tenon portion 20b is disposed so as to protrude from the other side surface in the longitudinal direction of the segment 20, and is inserted into the first tenon hole 12b of the first blade tip portion 12 on the leading edge side in the rotational direction B of the turbine rotor. Mated. And the head 20d of the 1st tenon part 20b has penetrated the 1st tenon hole 12b. The head portion 20d penetrating the first tenon hole 12b protrudes without being caulked by the first tenon hole 12b.
For this reason, the second tenon part 20a is fixedly fitted to the second tenon hole 12a, but the first tenon part 20b is movably fitted to the first tenon hole 12b.

  The tenon portions 20a and 20b of each segment 20 are formed such that the longitudinal direction of the blade tip portion 12 is the longitudinal direction of the tenon portion. In this embodiment, the tenon portions 20a and 20b are arc-shaped portions formed in a semicircle that is convex outside the same radius at both ends in the longitudinal direction, and linear portions formed above and below the paper surface connecting these arc portions. , Is composed of.

  FIG. 5 is an enlarged view of the tenon hole 12b and the tenon portion 20b shown in FIG. FIG. 6 is an enlarged view showing a curved portion 12b5 of the tenon hole 12b shown in FIG. 5 indicates the positional relationship between the first tenon hole 12b and the first tenon portion 20b during operation of the turbine rotor, and the two-dot chain line portion indicates the first tenon hole 12b when the turbine rotor is stopped. The positional relationship with the 1st tenon part 20b is shown.

  When the turbine blade 1 configured as described above is rotated in the arrow direction B, the blade effective portion 11 (see FIG. 1) of the blade 10 is deformed by twisting and the like due to the centrifugal force accompanying the rotation, and the turbine blade 1 will vibrate constantly.

  Due to this rotation, the blade tip 12 changes the acute angle between the longitudinal direction and the steam inlet direction to an acute angle smaller than the stop angle due to twisting back during operation of the turbine rotor. With this change, as shown in FIG. 5, the tenon hole 12b moves from the position of the two-dot chain line to the position of the solid line in the arrow direction E (the left direction of the paper). Further, the tenon portion 20b moves from the position of the two-dot chain line to the position of the solid line in the arrow direction G (upward on the paper surface). Thereby, the tenon part 20b is pressed against the front edge side of the tenon hole 12b and the linear part 12b1 side of the tenon hole 12b.

  When the turbine rotor is operated, if the upper right curved portion of the paper surface is the curved portion 12b9 (see the alternate long and short dash line) having the same shape as the other curved portions 12b6 to 12b8, the boundary between the curved portion 12b9 of the tenon hole 12b and the straight portion 12b1 A boundary region (hereinafter referred to as “shoulder portion”) V (region indicated by a one-dot chain circle in FIG. 5) between a circular arc portion and a linear portion of the tenon portion 20b (hereinafter referred to as “contact end”). 20b1 comes into contact.

  When the contact end 20b1 of the tenon portion 20b comes into contact with the shoulder contact portion V of the tenon hole 12b, stress due to the vibration of the turbine rotor blade 1 is strongly applied, and the shoulder contact portion V of the tenon hole 12b is caused by this stress. Cracks will occur. For this reason, at the time of operation of the turbine rotor, damage due to this crack occurs at the fitting portion between the blade tip 12 and the segment 20 of the turbine rotor blade 1, and for example, the necessity of replacement of the turbine rotor blade 1 occurs.

  Therefore, as shown in FIG. 5, in this embodiment, in order to prevent the contact end 20b1 of the tenon portion 20b from coming into contact with the shoulder contact portion V of the tenon hole 12b, it protrudes from the width L of the linear portions 12b1 and 12b2. A curved portion (hereinafter referred to as “relief portion”) 12b5 having a protruding region is provided.

  As shown in FIG. 6, this escape portion 12b5 has a radius r1 that is the same as the radius from the center point O1 of the dashed-dotted curve portion 12b9. The position of the center point O2 of the escape portion 12b5 is arranged away from the position of the center point O1 of the curved portion 12b9 by a distance s in the short direction of the tenon hole 12b, that is, upward in the drawing. The shape of the escape portion 12b5 is an arc longer than the arc of the ¼ curve portion 12b9 having a circumferential length and shorter than an arc having a circumferential length of half (semicircle). . That is, the relief portion 12b5 is formed such that when the center point O2 and both ends of the relief portion 12b5 are connected by a straight line, the angle θ at which the straight lines intersect is 90 ° <θ <180 °.

  Thus, in this embodiment, the tenon portion at the shoulder abutment portion V is provided by cutting the shoulder abutment portion V of the tenon hole 12b where the stress caused by the pressing of vibration generated during operation of the turbine rotor is strong and by providing the relief portion 12b5. The contact of the contact 20b with the contact end 20b1 is prevented, and the stress due to the pressing of the vibration is prevented from acting on the tenon hole 12b.

Next, the cutting of the shoulder portion V will be described with reference to FIG.
As shown in FIG. 6, the center point of the curved portion 12b9 is O1, and the radius of the curved portion 12b9 is r1. The center point O1 of the curved portion 12b9 is assumed to be equal to the center point of a cutting tool (not shown) for forming the curved portion 12b9, for example. This cutting tool has a disk shape with a cutting radius r1, for example.

  Here, similarly to the curved portions 12b6 to 12b8, first, the central point of the cutting tool is made to coincide with the central point O1 of the curved portion 12b9 to form the curved portion 12b9. Next, the tenon hole 12b is cut so as to form the escape portion 12b5 while moving the cutting tool by a distance s in the short direction of the tenon hole 12b, that is, above the paper surface, and the center point of the cutting tool is set to O2. Move to. The moving distance s is arbitrarily set according to the size of the shoulder abutment portion V. This cutting operation can be performed by, for example, offset machining.

  By this cutting operation, the curved portion 12b9 is expanded by cutting, and as shown in FIG. 5, a relief portion 12b5 having a protruding region protruding from the width L of the straight portions 12b1 and 12b2 can be formed. The formed relief portion 12b5 can cut the shoulder contact portion V, which is a boundary region including the boundary between the curved portion 12b9 and the straight portion 12b1 of the tenon hole 12b.

  Thereby, in this embodiment, as shown in FIG. 5, the contact end 20b1 of the tenon part 20b does not contact the tenon hole 12b during the operation of the turbine rotor. As a result, it is possible to prevent the occurrence of cracks due to stress due to the pressing of vibration generated during operation of the turbine rotor. As described above, in this embodiment, since the occurrence of cracks can be prevented, damage generated in the fitting portion between the blade tip portion 12 and the segment 20 of the turbine rotor blade 1 can be improved.

(Embodiment 2)
FIG. 7 is a DD arrow view of the second embodiment showing the upper surface of FIG. 1. FIG. 8 is an enlarged side view showing an enlarged side face of the blade tip 12 side of the moving blade shown in FIG. 7 as viewed from the blade belly side. 7 shows the time when the turbine rotor is stopped, and FIG. 8 shows the time when the turbine rotor is in operation.

  As shown in FIGS. 7 and 8, the blade tip portion 12 includes the blade top portion of the blade effective portion 11 in the shape of the lower surface and is formed integrally with the blade top portion, as in the first embodiment. . Further, the blade tip 12 is formed in a substantially rectangular parallelepiped with the cord direction of the blade tip of the blade effective portion 11 as the longitudinal direction. The length of the blade tip 12 in the longitudinal direction is a rhombus shaped segment 20. About twice as long as the length in the longitudinal direction. The blade tip portion 12 is provided with tenon holes 12a and 12b penetrating the side surface on the blade back 11a side and the side surface on the blade belly 11b side. The tenon holes 12a and 12b project from the side surface of the segment 20. The tenon portions 20a and 20b are inserted and fitted, thereby connecting the blade tip portions 12 of the moving blades 10 together.

  In this embodiment, the difference from the first embodiment is that the tenon portion 20a of the segment 20 is fitted with the tenon hole 12a of the blade tip portion 12 on the trailing edge side in the rotational direction of the turbine rotor, and the head portion 20c thereof is the tenon hole 12a. The head part 20c of the tenon part 20a protrudes without being caulked.

Further, the tenon portion 20b of the segment 20 is engaged with the tenon hole 12b of the blade tip portion 12 on the leading edge side in the rotational direction of the turbine rotor, and the head portion 20d passes through the tenon hole 12b and is then caulked to be the tip of the blade. This is a point fixed to the portion 12.
For this reason, although the tenon part 20b is fixedly fitted to the tenon hole 12b, the tenon part 20a is movably fitted to the tenon hole 12a.

  FIG. 9 is an enlarged view of the tenon hole and the tenon portion shown in FIG. 9 indicates the positional relationship between the tenon hole 12a and the tenon portion 20a during operation of the turbine rotor, and the two-dot chain line indicates the position of the tenon hole 12a when the turbine rotor is stopped.

  When the turbine rotor blade 1 having such a configuration is rotated in the arrow direction B, the blade effective portion 11 (see FIG. 1) of the rotor blade 10 undergoes deformation such as torsional return and vibrations are constantly generated in the turbine rotor blade 1. Will be.

  Due to this rotation, as in the first embodiment, the blade tip 12 has an acute angle formed by the longitudinal direction and the steam inlet direction (arrow direction A in the drawing of FIG. 7), and twist back during operation of the turbine rotor. Changes to an acute angle smaller than the angle at the time of stop. With this change, as shown in FIG. 9, the tenon hole 12a moves from the position of the two-dot chain line to the arrow direction F, that is, the position of the solid line on the right side of the drawing. Further, the tenon part 20a moves to the position of the solid line in the upward direction on the paper surface as in the first embodiment. Thereby, the tenon part 20a is pressed against the rear edge side of the tenon hole 12a and the linear part 12a1 side of the tenon hole 12a.

  When the turbine rotor is in operation, if the upper left curved portion of the paper is the curved portion 12a9 (see the alternate long and short dash line) having the same shape as the other curved portions 12a6 to 12a8, the shoulder portion W of the tenon hole 12a (one point in FIG. 9). The contact end 20a1 of the tenon portion 20b comes into contact with a region indicated by a chain line circle.

  When the contact end 20a1 of the tenon portion 20a abuts, the shoulder contact portion W of the tenon hole 12a is strongly stressed by the vibration of the turbine rotor blade 1, and the shoulder contact portion W of the tenon hole 12a is caused by this stress. Cracks will occur. For this reason, at the time of operation of the turbine rotor, damage due to this crack occurs at the fitting portion between the blade tip 12 and the segment 20 of the turbine rotor blade 1, and for example, the necessity of replacement of the turbine rotor blade 1 occurs.

  Therefore, as shown in FIG. 9, in this embodiment, in order to prevent the contact end 20a1 of the tenon portion 20a from coming into contact with the shoulder contact portion W of the tenon hole 12a, it protrudes from the width L of the straight portions 12a1 and 12a2. A relief portion 12a5 having a protruding region is provided.

  The position of the escape portion 12a5 is the same as that of the escape portion 12b5 shown in FIG. 6, and the position of the center point O2 of the escape portion 12a5 is shorter than the position of the center point O1 of the curved portion 12a9. It is a position that is separated by a distance s in the direction, that is, in the upward direction on the paper surface. The shape of the relief portion 12a5 is also an arc shape similar to that of the relief portion 12b5 of the first embodiment, the circumference is longer than the arc of the curved portion 12a5 that is ¼ of the circumference, and the circumference is long. The arc is shorter than the half arc (semicircle). That is, the relief portion 12a5 is formed such that when the center point O2 and both ends of the relief portion 12a5 are connected by a straight line, the angle θ at which the straight lines intersect is 90 ° <θ <180 °, as in FIG. .

  Thus, in this embodiment, the tenon portion at the shoulder abutment portion W is provided by cutting the shoulder abutment portion W of the tenon hole 12a where the stress caused by the pressing of vibration generated during operation of the turbine rotor is strong and by providing the relief portion 12a5. The contact with the contact end 20a1 of 20a is prevented, and the stress due to the pressing of this vibration is prevented from acting on the tenon hole 12a.

Next, cutting of the shoulder abutment portion W will be described with reference to FIG.
The cutting of the shoulder abutment portion W is substantially the same as the cutting of the shoulder abutment portion V shown in FIG. 6 except that the cutting position of the shoulder abutment portion W is axisymmetric about the shoulder abutment portion V and the central axis K. Is. Here, the center point of the curved portion 12a9 is O1, and the radius of the curved portion 12a9 is r1. The center point O1 of the curved portion 12a9 is assumed to be equal to the center point of a cutting tool (not shown) for forming the curved portion 12a9, for example. This cutting tool has a disk shape with a cutting radius r1, for example.

  Here, first, the curved portion 12a9 is formed by matching the center point of the cutting tool with the central point O1 of the curved portion 12a9. Next, the tenon hole 12a is cut so as to form the escape portion 12a5 while moving the cutting tool by a distance s in the short direction of the linear portion 12a1 of the tenon hole 12a, that is, upward in the drawing, and the center of the cutting tool is formed. Move the point to O2. The moving distance s is arbitrarily set according to the size of the shoulder abutment portion W. This cutting operation can be performed by, for example, offset machining.

  By this cutting operation, the curved portion 12a9 is cut and expanded, and as shown in FIG. 9, a relief portion 12a5 having a protruding region protruding from the width L of the straight portions 12a1 and 12a2 can be formed. With the formed relief portion 12a5, the shoulder contact portion W, which is a boundary region including the boundary between the curved portion 12a9 and the straight portion of the tenon hole 12a, can be cut.

  Thereby, in this embodiment, as shown in FIG. 9, the contact end 20a1 of the tenon portion 20a does not come into contact with the straight portion 12a1 of the tenon hole 12a during operation of the turbine rotor. As a result, it is possible to prevent the occurrence of cracks due to stress due to the pressing of vibration generated during operation of the turbine rotor. As described above, in this embodiment, since the occurrence of cracks can be prevented, damage generated in the fitting portion between the blade tip portion 12 and the segment 20 of the turbine rotor blade 1 can be improved.

(Embodiment 3)
FIG. 10 is a DD arrow view of the third embodiment showing the upper surface of FIG. 1. FIG. 11 is an enlarged side view showing an enlarged side surface on the blade tip portion 12 side of the moving blade 10 shown in FIG. 10 as viewed from the blade belly 11b side. FIG. 10 shows the time when the turbine rotor is stopped, and FIG. 11 shows the time when the turbine rotor is in operation.

  As shown in FIGS. 10 and 11, the blade tip portion 12 includes the blade top portion of the blade effective portion 11 in the shape of the lower surface and is formed integrally with the blade top portion, as in the first embodiment. . Further, the blade tip 12 is formed in a substantially rectangular parallelepiped with the cord direction of the blade tip of the blade effective portion 11 as the longitudinal direction. The length of the blade tip 12 in the longitudinal direction is a rhombus shaped segment 20. About twice as long as the length in the longitudinal direction. The blade tip portion 12 is provided with tenon holes 12a and 12b penetrating the side surface on the blade back 11a side and the side surface on the blade belly 11b side. The tenon holes 12a and 12b project from the side surface of the segment 20. By inserting and fitting the tenon portions 20a and 20b, the blade tip portions 12 of the moving blades 10 are coupled.

  In this embodiment, the difference from the first embodiment is that the tenon portions 20a and 20b of the segment 20 are respectively fitted with the tenon holes 12a and 12b of the blade tip portion 12 on the trailing edge side and the leading edge side in the rotational direction of the turbine rotor, and The heads 20c and 20d penetrate the tenon holes 12a and 12b, respectively, and the heads 20c and 20d of the tenon parts 20a and 20b protrude without being caulked. In other words, the tenon portions 20a and 20b are movably fitted in the tenon holes 12a and 12b without fixing the head portions 20c and 20d of the tenon portions 20a and 20b.

  FIG. 12 is an enlarged view of the tenon hole 12b and the tenon portion 20b shown in FIG. FIG. 13 is an enlarged view of another tenon hole 12a and another tenon portion 20a shown in FIG. In addition, the continuous line part in a figure shows the positional relationship of the tenon holes 12a and 12b and the tenon parts 20a and 20b at the time of operation | movement of a turbine rotor, respectively.

  When the turbine rotor blade 1 having such a configuration is rotated in the arrow direction B, the blade effective portion 11 (see FIG. 1) of the rotor blade 10 undergoes deformation such as torsional return and vibrations are constantly generated in the turbine rotor blade 1. Will be.

  Because of this rotation, as in the first embodiment, the blade tip 12 has an acute angle formed by the longitudinal direction and the steam inlet direction (arrow direction A in the drawing of FIG. 11), and twist back during operation of the turbine rotor. Changes to an acute angle smaller than the angle at the time of stop. With this change, the tenon hole 12b moves from the position of the two-dot chain line to the arrow direction E, that is, to the position of the solid line on the left side of the drawing, as in FIG. Further, the tenon portion 20b moves to the position of the solid line in the upward direction on the paper surface as in FIG. Thereby, the tenon part 20b is pressed on the front edge side of the tenon hole 12b and on the linear part 12b1 side of the tenon hole 12b (see FIG. 12).

  When the turbine rotor is operated, if the upper right curved portion of the paper surface is the curved portion 12b9 having the same shape as the other curved portions 12b6 to 12b8, the contact end 20b1 of the tenon portion 20b is brought into contact with the shoulder portion V of the tenon hole 12b. You will be in touch. However, in this embodiment, as shown in FIG. 12, in order to prevent the contact end 20b1 of the tenon portion 20b from coming into contact with the shoulder contact portion V of the tenon hole 12b, the first and second straight portions 12b1, 12b2 A relief portion 12b10 that protrudes from the width L and has a protruding region protruding from the width M of the third and fourth linear portions 12b3 and 12b4 is provided.

  Further, with the change in the acute angle formed by the longitudinal direction of the blade tip 12 and the steam inlet direction as described above, the tenon hole 12a extends from the position of the two-dot chain line in the arrow direction F, that is, on the paper surface. Move to the right solid line position. Further, the tenon part 20a moves to the position of the solid line in the upward direction on the paper surface as in the second embodiment. Thereby, the tenon part 20a is pressed against the rear edge side of the tenon hole 12a and the linear part 12a1 side of the tenon hole 12a (see FIG. 13).

  When the turbine rotor is operated, if the upper left curved portion of the paper surface is the curved portion 12a9 having the same shape as the other curved portions 12a6 to 12a8, the contact end 20a1 of the tenon portion 20a is brought into contact with the shoulder portion W of the tenon hole 12a. You will be in touch. However, in this embodiment, as shown in FIG. 13, in order to prevent the contact end 20a1 of the tenon portion 20a from coming into contact with the shoulder contact portion W of the tenon hole 12a, the fifth and sixth straight portions 12a1, 12a2 are used. And a relief portion 12a10 having a protruding region protruding from the width M of the seventh and eighth straight portions 12a3 and 12a4.

  As described above, in this embodiment, the shoulder abutments Wa and 12b of the tenon holes 12a and 12b where the stress due to the pressing of the vibration generated during the operation of the turbine rotor is strong are cut to provide the relief portions 12a10 and 12b10. The portions W and V are prevented from coming into contact with the contact ends 20a1 and 20b1 of the tenon portions 20a and 20b, and the stress caused by this vibration pressing is prevented from acting on the tenon holes 12a and 12b.

  Next, cutting of the shoulder portions W and V will be described. By the way, the cutting of the tenon holes 12a and 12b is not limited to the method shown in the first and second embodiments. In this embodiment, a method for cutting shoulder contact portions W and V will be described with reference to FIG. As shown in FIG. 11, the relief portions 12a10 and 12b10 are symmetrical about the central axis K, and the shoulder portions W and V are cut by the same method. The cutting method of the part V will be described with reference to FIG.

FIG. 14 is an enlarged view showing the escape portion 12b10 of the tenon hole 12b shown in FIG.
As shown in FIG. 14, the escape portion 12b10 is made of r2 whose radius from the center point O1 is larger by the length p than the radius r1 from the center point O1 of the curved portion 12b9. The shape of the escape portion 12b10 is formed in a substantially semicircular shape.

  The relief portion 12b10 is formed by cutting the shoulder contact portion V of the tenon hole 12b (the region indicated by a dashed line circle in FIG. 14) where the stress caused by the pressing of vibration during operation is strong, so that the tenon at the shoulder contact portion V is cut. The contact with the contact end 20b1 of the portion 20b can be prevented, and this stress can be prevented from acting on the tenon hole 12b.

  In the cutting of the shoulder portion V, as shown in FIG. 14, the center point of the curved portion 12b9 and the relief portion 12b10 is O1, the radius of the curved portion 12b9 is r1, and the radius of the relief portion 12b10 is r2. The center point O1 of the curved portion 12b9 and the relief portion 12b10 is assumed to be equal to the center point of a cutting tool (not shown) for forming the curved portion 12b9 and the relief portion 12b10, for example. This cutting tool is composed of, for example, a disk shape having a cutting radius r1 and a disk shape having a cutting radius r2.

  Here, first, the tenon hole 12b is cut by making the center point of the cutting tool having a disk shape with the cutting radius r1 coincide with the center point O1 of the curved portion 12b9 to form the curved portion 12b9 (see the one-dot chain line in the figure). To do. Next, the cutting tool is changed to a cutting tool having a disk shape with a cutting radius r2, and the tenon hole 12b including the curved portion 12b9 is formed so that the center portion of the cutting tool coincides with O1 and the escape portion 12b10 is formed. To cut. The cutting radius r2 of the cutting tool is arbitrarily set according to the size of the shoulder abutment portion V. This cutting operation can be performed by, for example, offset machining.

  By this cutting operation, the curved portion 12b9 is cut and expanded, and a semicircular curved portion 12b10 can be formed. The formed relief portion 12b10 can cut the shoulder contact portion V, which is a boundary region including the boundary between the curved portion 12b9 and the straight portion of the tenon hole 12b.

  In addition, this cutting operation can be performed by the same operation for the shoulder abutment portion W. In that case, after one shoulder abutment part, for example, shoulder abutment part V, is cut by offset machining, the other shoulder abutment part, for example, shoulder abutment part W, can be cut by offset machining.

  Thereby, in this embodiment, as shown in FIGS. 12 and 13, the contact ends 20a1 and 20b1 of the tenon portions 20a and 20b are in contact with the straight portions 12a1 and 12b1 of the tenon holes 12a and 12b during the operation of the turbine rotor. No longer. As a result, it is possible to prevent the occurrence of cracks due to stress due to the pressing of vibration generated during operation of the turbine rotor. As described above, in this embodiment, since the occurrence of cracks can be prevented, damage generated in the fitting portion between the blade tip portion 12 and the segment 20 of the turbine rotor blade 1 can be improved.

(Application examples)
FIG. 15 is an enlarged view of an application example showing the escape portion 12b11 of the tenon hole 12b shown in FIG.

  As shown in FIG. 15, in this application example, the contact end 20b1 (see FIG. 5) of the tenon portion 20b is applied to the shoulder contact portion V of the tenon hole 12b (the region indicated by the dashed-dotted circle in FIG. 15). In order to prevent contact, an escape portion 12b11 having a protruding region protruding from the width L (see FIG. 5) of the first and second linear portions 12b1 and 12b2 is provided.

  The escape portion 12b11 is composed of r2 whose radius from the center point O3 is larger by the length p than the radius r1 from the center point O1 of the curved portion 12b9. The position of the center point O3 of the escape portion 12b11 is arranged at a distance p from the position of the center point O1 of the curved portion 12b9 in the longitudinal direction of the tenon hole 12b, that is, in the left direction of the drawing. The shape of the escape portion 12b11 is an arc longer than the arc of the ¼ curve portion 12b9 of the circumferential length and shorter than an arc of half the circumference (semicircle). . That is, the relief portion 12b11 is formed such that when the center point O3 and both ends of the relief portion 12b11 are connected by a straight line, the angle θ at which the straight lines intersect is 90 ° <θ <180 °.

  The relief portion 12b11 is also abutted against the contact end 20b1 (see FIG. 12) of the tenon portion 20b at the shoulder contact portion V by cutting the shoulder contact portion V of the tenon hole 12b where the stress due to vibration pressing during operation is strong. The contact is prevented and this stress is prevented from acting on the tenon hole 12b.

Next, the cutting of the shoulder portion V will be described with reference to FIG.
As shown in FIG. 15, the center point of the curved portion 12b9 is O1, and the radius of the curved portion 12b9 is r1. The center point O1 of the curved portion 12b9 is assumed to be equal to the center point of a cutting tool (not shown) for forming the curved portion 12b9, for example. Further, the center point O3 of the escape portion 12b11 is assumed to be equal to the center point of a cutting tool (not shown) for forming the escape portion 12b11, for example.
That is, in this application example, two types of cutting tools are used, for example, one having a disk shape with a cutting radius r1 and one having a disk shape with a cutting radius r2.

  Here, similarly to the other curved portions 12b6 to 12b8 (see FIG. 5), first, the center point of the cutting tool having a disk shape with the cutting radius r1 is made to coincide with the center point O1 of the curved portion 12b9, and the tenon hole is made. 12b is cut to form a curved portion 12b9. Next, the cutting tool is changed to one having a disk shape with a cutting radius of r2, and the center point of the cutting tool is made to coincide with the center point O3 of the curved portion 12b11 so as to form a relief portion 12b11. The tenon hole 12b including the portion 12b9 is cut. The distance p is arbitrarily set according to the size of the shoulder abutment V. This cutting operation can be performed by, for example, offset machining.

  By this cutting operation, the curved portion 12b9 is cut and expanded, and a relief portion 12b11 having a protruding region (see FIG. 5) protruding from the width L of the first and second straight portions 12b1 and 12b2 can be formed. With the formed relief portion 12b11, the shoulder contact portion V, which is a boundary region including the boundary between the curved portion 12b9 and the straight portion of the tenon hole 12b, can be cut.

  In addition, this cutting operation can be performed by the same operation for the shoulder abutment portion W. In that case, after one shoulder abutment part, for example, shoulder abutment part V, is cut by offset machining, the other shoulder abutment part, for example, shoulder abutment part W, can be cut by offset machining.

  Accordingly, in this application example, the contact ends 20a1 and 20b1 of the tenon portions 20a and 20b are connected to the straight portions 12a1 of the tenon holes 12a and 12b during the operation of the turbine rotor, as in the third embodiment shown in FIGS. 12b1 (see FIGS. 12 and 13). As a result, it is possible to prevent the occurrence of cracks due to stress due to the pressing of vibration generated during operation of the turbine rotor. As described above, in this application example, since the occurrence of cracks can be prevented, the damage generated in the fitting portion between the blade tip 12 and the segment 20 of the turbine rotor blade 1 can be improved.

FIG. 16 is an enlarged view of another application example showing the escape portion 12b12 of the tenon hole 12b shown in FIG.
As shown in FIG. 16, in this application example, the tenon hole 12b is generated by forming only the shoulder portion V and forming the relief portion 12b12 without matching the arc of the curved portion 12b9 or the like. .

  In the removal of the shoulder abutment portion V, for example, a disc-shaped cutting tool having a cutting radius equal to or larger than the radius of the shoulder abutment portion V is used, and the shoulder abutment portion V is cut with the center of the cutting tool aligned with the center of the shoulder abutment portion V. Thus, the escape portion 12b12 is formed.

  By this cutting operation, the shoulder contact portion V is cut, and the relief portion 12b12 having a protruding region (see FIG. 5) protruding from the width L of the first and second linear portions 12b1 and 12b2 can be formed.

(Embodiment 4)
FIG. 17 is a DD arrow view of the fourth embodiment showing the upper surface of FIG. 1. 18 is an enlarged side view showing an enlarged side surface of the blade tip portion side of the moving blade 10 shown in FIG. 17 viewed from the blade belly 11b side.
In the embodiment described above, the tenon portions 20a and 20b protruding from the side surfaces of the segments 20 and 20 disposed on both sides are fitted into the tenon holes 12a and 12b provided on the side surfaces of the blade tip portion 12. However, as shown in FIG. 17, two tenon portions 20 a, 20 a and 20 b, 20 b may protrude from the side surface of one segment 20.

  The tenon portions 20a and 20a are respectively fitted with the tenon holes 12a and 12a of the blade tip portion 12 on the trailing edge side in the rotational direction of the turbine rotor, and the head portions 20c and 20c pass through the tenon hole 12a. The tenon parts 20b and 20b are fitted into the tenon holes 12b and 12b of the blade tip part 12 on the leading edge side in the rotational direction of the turbine rotor, and the head parts 20d and 20d pass through the tenon hole 12b. In other words, the tenon portions 20a and 20b are movably fitted in the tenon holes 12a and 12b without caulking the head portions 20c and 20d of the tenon portions 20a and 20b.

When the turbine rotor blade 1 having such a configuration is rotationally operated in the arrow direction B, as shown in FIG. 5, the tenon hole 12b is twisted back from the position of the two-dot chain line in the arrow direction E, as shown in FIG. That is, it moves to the position of the solid line on the left side of the page. Further, the tenon portion 20b is pressed against the front edge side of the tenon hole 12b and the linear portion 12b1 side of the tenon hole 12b.
At this time, if the upper right curved portion on the paper surface is the curved portion 12b9 having the same shape as the other curved portions, the contact end 20b1 abuts on the shoulder portion V (the region indicated by the alternate long and short dash line in FIG. 5), and the crack is Will occur.

Also, due to this rotation, as in the second embodiment, as shown in FIG. 9, the tenon hole 12a moves from the position of the two-dot chain line to the direction of the arrow F, that is, the position of the solid line on the right side of the page, by twisting back. To do. The tenon portion 20a is pressed against the rear edge side of the tenon hole 12a and the linear portion 12a1 side of the tenon hole 12a.
At this time, if the upper left curved portion of the paper is the curved portion 12a9 having the same shape as the other curved portions, the contact end 20a1 comes into contact with the shoulder abutment portion W (the region indicated by the alternate long and short dash line in FIG. 9), and cracks are generated. Will occur.

  Therefore, as shown in FIG. 18, also in this embodiment, as in the third embodiment, the first and second straight portions 12b1 and 12b2 protrude from the width L and the third and fourth straight portions 12b3 and 12b3 are projected. Curved portions 12b10 and 12b10 having projecting regions (see FIG. 12) projecting from the width M of 12b4 are provided. Further, the curved portions 12a10, which protrude from the width L of the fifth and sixth straight portions 12a1, 12a2 and have protruding regions (see FIG. 13) which protrude from the width M of the seventh and eighth straight portions 12a3, 12a4, 12a10 is provided.

As described above, by cutting the shoulder portions W and V to provide the curved portions 12a10, 12a10 and 12b10 and 12b10, the stress caused by the vibration during operation acts on the tenon holes 12a, 12a and 12b and 12b, respectively. Try to prevent.
The curved portions 12a10, 12a10 and 12b10, 12b10 can be formed by any of the cutting methods described in the application examples of the first to third embodiments and the third embodiment.

In this embodiment, the case where the heads 20c and 20d of the tenon parts 20a and 20b are not caulked in the tenon holes 12a and 12b has been described. For example, as in the first or second embodiment, the heads of the tenon parts 20a and 20b are used. The same applies to the case where the portions 20c and 20d are fixed by caulking in the tenon holes 12a and 12b of the blade tip portion 12 on the trailing edge side or the leading edge side in the rotational direction.
Moreover, although this embodiment demonstrated the case where the tenon holes 12a and 12b and the tenon parts 20a and 20b were four, it is applicable not only to four but three or more, for example.

  Thereby, also in this embodiment, the contact ends 20a1 and 20b1 of the tenon portions 20a and 20b do not contact the linear portions 12a1 and 12b1 of the tenon holes 12a and 12b during the operation of the turbine rotor, as in the third embodiment (see FIG. 12, see FIG. As a result, it is possible to prevent the occurrence of cracks due to stress due to the pressing of vibration generated during operation of the turbine rotor. As described above, in this embodiment, since the occurrence of cracks can be prevented, damage generated in the fitting portion between the blade tip portion 12 and the segment 20 of the turbine rotor blade 1 can be improved.

(Embodiment 5)
In the above-described embodiment, the case of the substantially rectangular tenon holes 12a and 12b has been described. However, the tenon hole according to the present invention is not limited to this.
FIG. 19 is an enlarged view of another example of the tenon hole 12c and the tenon portion.

  As shown in FIG. 19, for example, the tenon hole 12c has openings through the side surfaces 12c and 12d shown in FIG. 3, and is connected to the two straight portions 12c1 and 12c2 and the straight portions 12c1 and 12c2. Two curve portions 12c3 and 12c4.

Since the straight portions 12c1 and 12c2 have the same configuration as the straight portions 12a1 and 12a2 described above, description thereof is omitted here.
The curved portion 12c4 has a semicircular shape and is connected to the straight portions 12c1 and 12c2 on the rear edge side.
The curved portion 12c3 is connected to the straight portions 12c1 and 12c2 on the front edge side. The curved portion 12c3 is provided with a relief portion 12c5 having a protruding region protruding from the width of the linear portions 12c1 and 12c2 in order to prevent the contact end 20b1 of the tenon portion 20b from coming into contact with the shoulder contact portion V of the tenon hole 12c. It has been.

  Similarly to the escape portion 12b5 shown in FIG. 6, the escape portion 12c5 has a radius from the center point that is the same as the radius from the center point O1 of the curved line portion 12c6 indicated by the alternate long and short dash line. The position of the center point of the escape portion 12c5 is arranged away from the position of the center point of the curved portion 12c6 by a predetermined distance in the short direction of the tenon hole 12c, that is, upward in the drawing. The shape of the relief portion 12c5 and the cutting of the shoulder contact portion V are the same as those in the first embodiment, and thus the description thereof is omitted here.

  In this embodiment having the tenon hole 12c having such a configuration, similarly to the above-described embodiment, the shoulder portion V of the tenon hole 12c in which the stress due to the pressing of vibration generated during operation of the turbine rotor is strongly worked is cut away. By providing the portion 12c5, it is possible to prevent the shoulder portion V from coming into contact with the contact end 20b1 of the tenon portion 20b, and it is possible to prevent the stress due to the pressing of this vibration from acting on the tenon hole 12c.

  Thereby, in this embodiment, as shown in FIG. 5, the contact end 20b1 of the tenon portion 20b does not contact the tenon hole 12c during operation of the turbine rotor. As a result, it is possible to prevent the occurrence of cracks due to stress due to the pressing of vibration generated during operation of the turbine rotor. As described above, in this embodiment, since the occurrence of cracks can be prevented, damage generated in the fitting portion between the blade tip portion 12 and the segment 20 of the turbine rotor blade 1 can be improved.

  In addition, this invention is not limited only to embodiment mentioned above, You may change a component in the range which does not deviate from the summary in an implementation stage. Various inventions can be configured by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 1 ... Turbine blade, 2 ... Turbine wheel implantation part, 10 ... Rotor blade, 11 ... Blade effective part, 11a ... Blade back, 11b ... Blade back, 12 ... Blade tip part, 12a ... Tenon hole, 12a1-12a4 ... Straight line Part, 12a5, 12b5, 12a11, 12b11, 12b12 ... relief part, 12a6-12a11 ... curved part, 12b, 12c ... tenon hole, 12b1-12b4, 12c1, 12c2 ... linear part, 12b5-12b11, 12c3, 12c4 ... curved part 12c, 12d ... side face, 13 ... wing implantation part, 14 ... sleeve, 20 ... segment, 20a ... tenon part, 20a1 ... contact end, 20b ... tenon part, 20b1 ... contact end, 20c, 20d ... head, O1, O2, O3 ... center point, p ... distance, r1, r2 ... radius, s ... moving distance, L, M ... width, W, V ... shoulder contact, [theta] ... angle.

Claims (12)

A first blade effective portion having a first blade top portion twisted about a first axis K substantially perpendicular to the rotation axis of the turbine and having a back portion and an abdominal portion and having a cord direction different from the direction of the first axis K;
A first blade tip disposed on the first blade tip and having side surfaces corresponding to each other along a surface defined by the direction of the first axis K and the cord direction;
A second blade effective portion comprising a second blade top portion twisted about a second axis K substantially perpendicular to the rotation axis of the turbine and having a back portion and an abdominal portion and a cord direction different from the direction of the second axis K; ,
A second blade tip portion disposed on the second blade tip and having side surfaces corresponding to each other along a surface defined by the direction of the second axis K and the cord direction;
A first portion having a straight line portion penetrating through the side surfaces of the first blade effective portion, at least along a cord direction of the first blade tip portion and opposed to each other, and a curved portion connected to the straight line portion; Tenon hole,
A second portion having a straight line portion penetrating through the side surfaces of the second blade effective portion, at least along the cord direction of the second blade tip portion and opposed to each other, and a curved portion connected to the straight line portion; Tenon hole,
The first, is arranged between the second wing tip, and a first tenon portion of the convex shape to be inserted into the first tenon hole, a second tenon portion having a convex shape to be inserted into the second tenon hole, have a, first, at least one of the second tenon portion, anda segment fitted movably relative to the first, second tenon hole,
At least one of the curved portions of the first and second tenon holes into which the first and second tenon portions are movably fitted has a relief portion protruding from a width between the straight portions. Turbine blades. The straight portion of the first tenon hole is composed of first and second straight portions,
The first straight portion is disposed on the tip side of the first blade effective portion from the second straight portion,
The turbine rotor blade according to claim 1, wherein the escape portion of the first tenon hole protrudes from the first linear portion side. The turbine rotor blade according to claim 2, wherein the escape portion of the first tenon hole protrudes from a front side of the first linear portion in the rotation direction of the turbine. The straight portion of the second tenon hole is composed of third and fourth straight portions,
The third straight portion is disposed on the tip side of the second wing effective portion from the fourth straight portion,
The turbine blade according to any one of claims 1 to 3, wherein the escape portion of the second tenon hole protrudes from the third linear portion side. Wherein the relief portion of the second tenon hole, before Symbol turbine blade according to claim 2, characterized in that projecting from the rotation direction rear side of the turbine of the third linear portion. The turbine rotor blade according to any one of claims 1 to 5, wherein the escape portion has an arc shape. The curved portion has an arc shape,
The turbine rotor blade according to claim 6, wherein the escape portion has the same radius as the curved portion. The curved portion has an arc shape,
The turbine rotor blade according to claim 6, wherein the escape portion has a larger radius than the curved portion. The turbine blade according to any one of claims 1 to 8, wherein the first tenon hole has a cord direction of a tip portion of the first blade as a longitudinal direction. The third tenon hole further penetrating through the side surfaces of the first blade effective portion and arranged side by side in the longitudinal direction along the first tenon hole and the cord direction. The turbine rotor blade according to any one of 1 to 9. The turbine blade according to claim 10, wherein the first and third tenon holes are arranged along the cord direction. A steam turbine comprising the turbine rotor blade according to any one of claims 1 to 11.

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