Runner and manufacturing method thereof

Abstract

To provide a runner or the like which can be efficiently manufactured.SOLUTION: In a runner of an embodiment, a plurality of blades are arranged between a crown and a band in a rotation direction. The runner comprises a plurality of runner segments. The runner segments include: crown segments constituted by dividing the crown into the number of the plurality of blades in the rotation direction; and band segments constituted by dividing the band into the number of the plurality of blades in the rotation direction, and one of the blades is arranged between the crown segments and the band segments. In the runner, a clearance between joining faces of the plurality of crown segments and a clearance between joining faces of the plurality of band segments are joined to each other in the rotation direction, and the joining faces are line-woven faces.SELECTED DRAWING: Figure 5B

Description

[Technical field]

[0001] SUMMARY OF THE DISCLOSURE Embodiments of the present invention relate to a runner and a method for manufacturing the same. [Background technology]

[0002] Fig. 7 is a partial cross-sectional view showing a schematic view of a main part of a Francis type water turbine 90 according to the related art. In Fig. 7, the longitudinal direction is the vertical direction z, the lateral direction is the first horizontal direction x, and the direction perpendicular to the paper surface is the second horizontal direction y perpendicular to the vertical direction z and the first horizontal direction x.

[0003] As shown in FIG. 7, a Francis type water turbine 90 includes a runner 1, and is configured so that the runner 1 rotates in a rotation direction R about a rotation axis AX that is an axis along a vertical direction z, for example.

[0004] The runner 1 has a crown 2, blades 3, and a band 4, and a plurality of blades 3 are arranged between the crown 2 and the band 4 in the direction R of rotation.

[0005] When the Francis type water turbine 90 is operating in turbine mode (power generation mode), water is introduced into the runner 1 from the casing 96 through the guide vanes 95 and flows from the outer periphery to the inner periphery of the runner 1. This causes the runner 1 to rotate together with the main shaft 92. That is, in the runner 1, the pressure energy of the water is converted into rotational energy. The rotational energy of the runner 1 is then transmitted to the generator 98 through the main shaft 92, and power is generated in the generator 98. When the turbine is operating, the water flowing out of the runner 1 is discharged to the outside (for example, a lower pond) through the draft pipe 97.

[0006] FIG. 8 is an exploded perspective view showing an example of a disassembled state before the runner 1 is assembled in a Francis type water turbine according to the related art.

[0007] As shown in Fig. 8, the runner 1 is produced by combining the following components: a disk-shaped crown 2, an annular band 4, and a number of blades 3. The multiple blades 3 are joined to the crown 2 and the band 4, respectively. Here, the crown 2 and the blades 3, and the blades 3 and the band 4 are often joined by, for example, arc welding. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2010-53797 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, when joining by arc welding, the heat input by arc welding is large, which may cause thermal deformation of the runner 1. For this reason, instead of arc welding, which has a large heat input, joining by laser welding, which has a small heat input, is being considered.

[0010] Fig. 9 is a diagram showing a state where a blade 3 is joined to a band 4 by laser welding in the related art. In Fig. 9, the longitudinal direction is the vertical direction z, the lateral direction is the first horizontal direction x, and the direction perpendicular to the paper surface is the second horizontal direction y.

[0011] As shown in Fig. 9, the laser welding is performed by irradiating the laser L from the laser head 7 to the butt joint 6 between the blade 3 and the band 4. The butt joint 6 is located between the blade 3 and the band 4, which are aligned in the axial direction along the rotation axis of the runner 1. Here, it is necessary to irradiate the laser L by accurately moving the laser head 7 along the butt joint 6.

[0012] However, when performing laser welding, if the space in which the laser head 7 is installed is narrow, it may be difficult to accurately move the laser head 7 along the butt joint 6. For example, the inner part of the runner 1, such as the inside of the radial direction (here, corresponding to the first horizontal direction x) of the annular band 4, has a narrow space, so it may be difficult to install the laser head 7. Although not shown in the drawings, a similar problem may occur when joining the blade 3 to the crown 2 by laser welding.

[0013] Due to the above circumstances, it has not been easy to efficiently manufacture runners by laser welding in the past.

[0014] Therefore, the problem to be solved by the present invention is to provide a runner that can be efficiently manufactured, and a method for manufacturing the same. [Means for solving the problem]

[0015] In the embodiment, the runner has a plurality of blades arranged in the rotational direction between the crown and the band. The runner includes a plurality of runner segments. The runner segments include a crown segment formed by dividing the crown into a number of blades in the rotational direction, and a band segment formed by dividing the band into a number of blades in the rotational direction, and one of the blades is arranged between the crown segment and the band segment. In the runner, the joint surfaces of the plurality of crown segments and the joint surfaces of the plurality of band segments are joined in the rotational direction, and the joint surfaces are ruled surfaces. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing an example of a state after a runner 10 has been assembled in a Francis water turbine according to an embodiment. [Diagram 2]FIG. 2 is an exploded perspective view showing an example of a completed state before the runner 10 is assembled in the Francis type water turbine according to the embodiment. [Figure 3A] FIG. 3A is a side view showing an example of a disassembled state before the runner 10 is assembled in the Francis water turbine according to the embodiment. [Figure 3B] FIG. 3B is a top view showing an example of a disassembled state before the runner 10 is assembled in the Francis water turbine according to the embodiment. [Figure 3C] FIG. 3C is a bottom view showing an example of a disassembled state before the runner 10 is assembled in the Francis water turbine according to the embodiment. [Figure 4] FIG. 4 is a perspective view showing a runner segment 101 that constitutes the runner 10 according to the embodiment. [Figure 5A] FIG. 5A is a perspective view showing a state in which the runner 10 is manufactured in the embodiment. [Figure 5B] FIG. 5B is a diagram showing a state in which a laser welding process is performed in the embodiment. [Figure 5C] FIG. 5C is a diagram showing a laser L irradiated in laser welding and a joining surface S401 of a band segment 401 in the embodiment. [Figure 6A] FIG. 6A is a perspective view showing a state in which a runner 10 is manufactured in a modified embodiment. [Figure 6B] FIG. 6B is a perspective view showing a state in which the runner 10 is manufactured in the modified embodiment. [Figure 6C] FIG. 6C is a perspective view showing a state in which the runner 10 is manufactured in the modified embodiment. [Figure 7] FIG. 7 is a partial cross-sectional view that shows a schematic view of a main part of a Francis type water turbine 90 according to the related art. [Figure 8] FIG. 8 is an exploded perspective view showing an example of a disassembled state before the runner 1 is assembled in a Francis type water turbine according to the related art. [Figure 9]FIG. 9 is a diagram showing how blade 3 is joined to band 4 by laser welding in the related art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] [A] Runner 10 Configuration Fig. 1 is a perspective view showing an example of a completed state after a runner 10 is assembled in a Francis type water turbine according to an embodiment. Fig. 2 is a perspective view showing an example of a disassembled state before a runner 10 is assembled in a Francis type water turbine according to an embodiment.

[0018] 1 and 2, the Francis type water turbine of this embodiment is configured similarly to that of the related art, except that the configuration of the runner 10 is different from that of the related art (see FIG. 9). Therefore, descriptions of overlapping points will be omitted as appropriate.

[0019] In this embodiment, as shown in Fig. 1, the runner 10 has a plurality of blades 30 arranged in the rotational direction between the crown 20 and the band 40, similar to the related art (see Fig. 9). However, unlike the related art (see Fig. 9), the runner 10 of this embodiment includes, as a component, runner segments 101 that are configured by dividing the runner 10 into a plurality of segments in the rotational direction, as shown in Fig. 2, and is manufactured by combining a plurality of runner segments 101.

[0020] Fig. 3A is a side view showing an example of a disassembled state before the runner 10 is assembled in the Francis type water turbine according to the embodiment. Fig. 3B is a top view showing an example of a disassembled state before the runner 10 is assembled in the Francis type water turbine according to the embodiment. Fig. 3C is a bottom view showing an example of a disassembled state before the runner 10 is assembled in the Francis type water turbine according to the embodiment.

[0021] FIG. 4 is a perspective view showing a runner segment 101 that constitutes the runner 10 according to the embodiment.

[0022] The runner segment 101 includes a crown segment 201 and a band segment 401, as shown in FIGS. 3A, 3B, 3C, and 4.

[0023] In the runner segment 101, the crown segment 201 is configured by dividing the crown 20 into a number of blades 30 in the rotational direction (see FIG. 3B). The band segment 401 is configured by dividing the band 40 into a number of blades 30 in the rotational direction. One blade 30 is provided between the crown segment 201 and the band segment 401 (see FIG. 3C). In the runner segment 101, the crown segment 201, the band segment 401, and the blade 30 are integrally configured (see FIG. 3A and FIG. 4).

[0024] In this embodiment, the runner 10 is produced by joining the joining surfaces S201 of the multiple crown segments 201 and the joining surfaces S401 of the multiple band segments 401 in the rotational direction (see FIG. 4).

[0025] Each of the joint surface S201 of the crown segment 201 and the joint surface S401 of the band segment 401 is a ruled surface. Here, the joint surface S201 of the crown segment 201 is, for example, a curved surface whose curvature changes along the shape of the crown 20 (see FIG. 4). The joint surface S401 of the band segment 401 is, for example, a curved surface whose curvature changes along the shape of the band 40 (see FIG. 4).

[0026] [B] Method for manufacturing runner 10 A procedure for manufacturing the runner 10 of this embodiment will be described.

[0027] FIG. 5A is a perspective view showing a state in which the runner 10 is manufactured in the embodiment.

[0028] As shown in Fig. 5A, when manufacturing the runner 10, a laser welding process is performed in which the multiple band segments 401 are joined by laser welding using a laser head 7. Although not shown in the figure, a laser welding process is also performed in which the multiple crown segments 201 are joined by laser welding using the laser head 7. The laser welding process is performed in a state in which the runner segments 101 divided into multiple pieces are assembled in the rotational direction of the runner 10.

[0029] FIG. 5B is a diagram showing a state in which a laser welding process is performed in the embodiment.

[0030] 5B, in the laser welding process of this embodiment, laser welding is performed by irradiating a laser L from a laser head 7 to a butt joint 402 between multiple band segments 401. Laser welding is performed with the laser head 7 disposed on the outside of an annular band 40 formed by combining multiple band segments 401. Here, the laser head 7 irradiates the laser L to the butt joint 402 from the outer surface of the band segment 401 that is located opposite to the inner surface on which the blades 30 are installed.

[0031] Although not shown in the drawings, laser welding is also performed on the butt joint 202 between the multiple crown segments 201 with the laser head 7 disposed on the outside of the disk-shaped crown 20 formed by combining the multiple crown segments 201. That is, the laser head 7 irradiates the laser L onto the butt joint 202 from the outer surface of the crown segment 201 that is located opposite to the inner surface on which the blades 30 are installed.

[0032] Thus, in this embodiment, laser welding is performed by disposing the laser head 7 on the outside of the runner 10, which is made up of a plurality of runner segments 101 combined in the rotational direction of the runner 10, where no blades 30 are installed.

[0033] FIG. 5C is a diagram showing a laser L irradiated in laser welding and a joining surface S401 of a band segment 401 in the embodiment.

[0034] 5C, in laser welding, the laser L is irradiated along a straight line that describes a ruled surface that is the joining surface S401 of the band segment 401. Here, laser welding is performed by irradiating the laser L along the thickness direction of the band segment 401. Although not shown in the figure, in performing laser welding, the laser L is also irradiated in the same manner on the joining surfaces S201 of the multiple crown segments 201.

[0035] [C] Summary As described above, the runner 10 of this embodiment includes the runner segment 101, which is configured by dividing the crown 20 into a plurality of segments in the rotational direction, as a component, and is manufactured by combining a plurality of the runner segments 101. Here, the runner segment 101 includes the crown segment 201 configured by dividing the crown 20 into a plurality of blades 30 in the rotational direction, and the band segment 401 configured by dividing the band 40 into a plurality of blades 30 in the rotational direction, and one blade 30 is disposed between the crown segment 201 and the band segment 401. The joint surfaces S201 of the plurality of crown segments 201 and the joint surfaces S401 of the plurality of band segments 401 are joined by laser welding. The joint surfaces S201 of the crown segment 201 and the joint surfaces S401 of the band segment 401 are line-ruled surfaces.

[0036] Therefore, in this embodiment, when the runner 10 is produced, as described above, laser welding can be performed with the laser head 7 disposed outside the runner 10 in which a plurality of runner segments 101 are combined. As a result, in this embodiment, it is easy to accurately move the laser head 7 along the butt joints 402 between the plurality of band segments 401 and the butt joints 202 between the plurality of crown segments 201. Therefore, in this embodiment, the runner 10 can be produced easily.

[0037] [D] Variation 6A to 6C are perspective views showing the state during the manufacture of a runner 10 in a modified embodiment.

[0038] As shown in FIGS. 6A-6C, laser welding may be performed using a welding robot apparatus including robot arms 500a, 500b.

[0039] Specifically, as shown in Fig. 6A, a welding robot device is prepared with a laser head 7 attached to a robot arm 500a. When performing laser welding, the operation of the welding robot device is controlled and the posture of the laser head 7 is adjusted so that the laser head 7 irradiates the laser L to the butted portions 202, 402 at an appropriate angle with the runner 10 before welding fixed in an appropriate posture.

[0040] 6B, a welding robot device is prepared in which the runner 10 before welding is attached to a robot arm 500b. When performing laser welding, the operation of the welding robot device is controlled to adjust the posture of the runner 10 so that the laser L is irradiated to the butted portions 202, 402 at an appropriate angle with the laser head 7 fixed in an appropriate posture.

[0041] 6C, a welding robot device is prepared in which the laser head 7 is attached to a robot arm 500a, and another welding robot device is prepared in which the runner 10 before welding is attached to a robot arm 500b. When performing laser welding, the operation of the welding robot device is controlled and the attitude of the laser head 7 and the attitude of the runner 10 are adjusted so that the laser L is irradiated onto the butted portions 202, 402 at an appropriate angle.

[0042] The above-mentioned laser welding is controlled by using a control program for executing the above-mentioned laser welding, based on data such as position information of the butted portions 202, 402 of the runner 10 before welding.

[0043] <Other> Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0044] 1: runner, 2: crown, 3: blade, 4: band, 6: butt joint, 7: laser head, 10: runner, 20: crown, 30: blade, 40: band, 90: Francis turbine, 92: main shaft, 95: guide vane, 96: casing, 97: draft tube, 98: generator, 101: runner segment, 201: crown segment, 202: butt joint, 401: band segment, 402: butt joint, 500a: robot arm, 500b: robot arm, AX: rotation axis, L: laser, R: rotation direction, S201: joint surface, S401: joint surface, x: first horizontal direction, y: second horizontal direction, z: vertical direction

Claims

1. A runner having a plurality of blades arranged in a rotational direction between a crown and a band, a crown segment formed by dividing the crown into the number of the plurality of blades in the rotational direction, and a band segment formed by dividing the band into the number of the plurality of blades in the rotational direction, and one of the blades is disposed between the crown segment and the band segment. Equipped with multiple The joint surfaces of the crown segments and the joint surfaces of the band segments are joined in the rotational direction, The joining surface is a ruled surface. Runner.

2. A method for manufacturing the runner of claim 1, comprising the steps of: A laser welding step of joining the plurality of crown segments and the band segments by laser welding. having A method for manufacturing runners.

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