Variable vane device maintenance method and variable vane device

1. A variable vane device maintenance method for a variable vane device provided in a rotary machine, the variable vane device including:

a plurality of variable vanes disposed in an annular shape to surround a fluid passage;

a ring supported to be rotatable about a center axis of the rotary machine by a plurality of guides provided at an outer peripheral portion of the rotary machine, and connected to the plurality of variable vanes;

an attachment bracket fixed to the ring; and

a driving device connected to the attachment bracket, the driving device rotating the ring to swing the plurality of variable vanes,

the variable vane device maintenance method comprising:

a preparation step of preparing the ring including a first connection portion at which the attachment bracket is attached and a second connection portion at which the attachment bracket is attached at a position shifted from the first connection portion in a circumferential direction, the ring having the attachment bracket attached at the first connection portion;

a release step of releasing a connection between the plurality of variable vanes and the ring and a connection between the ring and the attachment bracket at the first connection portion;

a rotation step of rotating the ring by a predetermined angle; and

a connection step of connecting the plurality of variable vanes to the ring at positions different from positions before the release step and connecting the ring to the attachment bracket at the second connection portion.

2. The variable vane device maintenance method according to claim 1 , wherein

the plurality of variable vanes are connected to the ring through a link mechanism, the link mechanism is disassembled in the release step, and the link mechanism is assembled in the connection step.

3. The variable vane device maintenance method according to claim 1 , wherein

the ring is rotated by 180° in the rotation step.