Stationary vane unit of rotary machine, method of producing the same, and method of connecting the same

1. A stationary vane unit of a rotary machine in which a plurality of stationary vane members is arranged around a central axis and outer shrouds formed in outer peripheries of the stationary vane members are continuous in a circumferential direction so as to be connected to each other, the stationary vane unit comprising:

a first band member that extends in the circumferential direction and is accommodated in a first groove formed in the outer shrouds of the plurality of stationary vane members on a first side of the outer shrouds in a main axial direction in which the central axis extends;

a second band member that extends in the circumferential direction and is accommodated in a second groove formed in the outer shrouds of the plurality of stationary vane members on a second side of the outer shrouds in the main axial direction; and

a fastening member that fastens the first band member and the second band member to each other so that the outer shrouds of the plurality of stationary vane members are connected to each other and the fastening member penetrates through the first band member, one of the outer shrouds, and the second band member in the main axial direction.

2. The stationary vane unit of the rotary machine according to claim 1 ,

wherein at least one of the first band member and the second band member is fitted to the outer shrouds of the plurality of stationary vane members.

3. The stationary vane unit of the rotary machine according to claim 1 ,

wherein the fastening member is one of a plurality of fastening members provided in the circumferential direction at intervals, and at least one stationary vane member is positioned between two fastening members which make a pair and are adjacent to each other in the circumferential direction.

4. The stationary vane unit of the rotary machine according to claim 1 ,

wherein at least one of the first band member and the second band member is formed in an annular shape.

5. The stationary vane unit of the rotary machine according to claim 1 ,

wherein at least one of the first band member and the second band member is formed in an annular shape and is divided into multiple circular arc band bodies.

6. The stationary vane unit of the rotary machine according to claim 1 ,

wherein at least one of the first band member and the second band member is buried in one of the outer shrouds of the stationary vane members, and includes a crushed portion which is plastically deformed toward the one of the outer shrouds.

7. The stationary vane unit of the rotary machine according to claim 1 ,

wherein the one of the outer shrouds includes a penetration portion through which the fastening member passes and which extends from a first side of the one of the outer shrouds toward a second side of the one of the outer shrouds in the main axial direction.

8. The stationary vane unit of the rotary machine according to claim 1 , wherein the fastening member is a fastening bolt.

9. The stationary vane unit of the rotary machine according to claim 8 , wherein an axial length of the fastening bolt is less than or equal to an axial thickness of the one of the outer shrouds.

10. The stationary vane unit of the rotary machine according to claim 1 , wherein the fastening member has a head at a terminal end of the fastening member, the head being exposed outside one of the first band member and the second band member.

11. A method of producing a stationary vane unit of a rotary machine in which a plurality of stationary vane members is arranged around a central axis and outer shrouds formed in outer peripheries of the stationary vane members are continuous in a circumferential direction so as to be connected to each other, the method comprising:

preparing the plurality of stationary vane members, a first band member which extends in the circumferential direction and is connected with a first end portion of each of the outer shrouds from a first side of the outer shrouds in a main axial direction in which the central axis extends, and a second band member which extends in the circumferential direction around the central axis and is connected with a second end portion of each of the outer shrouds from a second side of the outer shrouds in the main axial direction;

arranging the plurality of stationary vane members in the circumferential direction while one of the first end portion and the second end portion of each of the outer shrouds of the stationary vane members is fitted to one of the first band member and the second band member which is placed on a work support surface;

fitting the other of the first band member and the second band member to the other of the first end portion and the second end portion of each of the outer shrouds continuously in the circumferential direction; and

fastening the first band member and the second band member to each other by a fastening member so that the outer shrouds of the stationary vane members are connected to each other and the fastening member penetrates through the first band member, one of the outer shrouds, and the second band member in the main axial direction.

12. The method of producing the stationary vane unit of the rotary machine according to claim 11 ,

wherein, in the preparing step, one of the first end portion and the second end portion of the one of the outer shrouds of the stationary vane members is provided with a concave portion, and one of the first band member and the second band member is provided with a convex portion which includes a base portion extending in the circumferential direction and formed in a flat shape and a protruding portion protruding in a direction perpendicular to the circumferential direction, the protruding portion including a reference surface extending in the circumferential direction, and

wherein, in the fastening step, the convex portion of the one of the first band member and the second band member is fitted to the concave portion of the one of the first end portion and the second end portion of the one of the outer shrouds of the stationary vane members, and the other of the first end portion and the second end portion of the one of the outer shrouds of the stationary vane members is fastened to the reference surface of the one of the first band member and the second band member by the fastening member while being pressed against the reference surface.

13. The method of producing the stationary vane unit of the rotary machine according to claim 11 ,

wherein a band cutting margin is provided in advance in at least one of the first band member and the second band member, and

wherein the band cutting margin is cut so as to adjust a size thereof after the fastening step.

14. The method of producing the stationary vane unit of the rotary machine according to claim 13 ,

wherein a shroud cutting margin is provided in advance in one of the outer shrouds of the stationary vane members so as to be continuous with the band cutting margin, and

wherein the shroud cutting margin is cut so as to adjust a size thereof together with the band cutting margin after the fastening step.

15. The method of producing the stationary vane unit of the rotary machine according to claim 11 ,

wherein in the fitting step, at least one of the first band member and the second band member is buried in one of the outer shrouds of the stationary vane members, and

wherein after the fastening step, the one of the first band member and the second band member buried in the one of the outer shrouds is plastically deformed toward the one of the outer shrouds, so that a gap between the at least one of the first band member and the second band member buried in the one of the outer shrouds and the one of the outer shrouds is filled.

16. The method of producing the stationary vane unit of the rotary machine according to claim 11 , wherein the fastening member is a fastening bolt.

17. The method of producing the stationary vane unit of the rotary machine according to claim 16 , wherein an axial length of the fastening bolt is less than or equal to an axial thickness of the one of the outer shrouds.

18. A method of connecting a stationary vane unit of the rotary machine in which a plurality of stationary vane members is arranged around a central axis and outer shrouds formed in outer peripheries of the stationary vane members are continuous in a circumferential direction so as to be connected to each other, the method comprising:

providing a first band member extending in the circumferential direction in the circumferentially continuous outer shrouds of the plurality of stationary vane members from a first side in a main axial direction in which the central axis extends so as to be accommodated in a first groove formed on the first side of the outer shrouds;

providing a second band member extending in the circumferential direction from a second side in the main axial direction so as to be accommodated in a second groove formed on the second side of the outer shrouds; and

fastening the first band member and the second band member to each other by a fastening member so that the outer shrouds of the plurality of stationary vane members are connected to each other and the fastening member penetrates through the first band member, one of the outer shrouds, and the second band member in the main axial direction.

19. The method of connecting the stationary vane unit of the rotary machine according to claim 18 , wherein the fastening member is a fastening bolt.

20. The method of connecting the stationary vane unit of the rotary machine according to claim 19 , wherein an axial length of the fastening bolt is less than or equal to an axial thickness of the one of the outer shrouds.