Axial-Flow Compressor and Modification Method

An axial-flow compressor comprising:

• stator vane rows that are located at a plurality of stages and include variable stator vanes that extend in a radial direction of the axial-flow compressor and rotate around rotary shafts of the variable stator vanes so as to adjust angles of the variable stator vanes;
• a plurality of rings that are connected to the stator vane rows located at the plurality of stages and drive and rotate the variable stator vanes of the stator vane rows that correspond to the rings, respectively;
• a plurality of levers that correspond to the plurality of rings, respectively;
• a rotary shaft that holds the plurality of levers so as to enable the levers to pivot, extends in a direction of extension of an axis of the axial-flow compressor, connects the plurality of levers to each other so that the plurality of levers are fixed to the rotary shaft and integrated with each other through the rotary shaft;
• a plurality of connecting rods that connect the plurality of rings to the levers that correspond to the rings, respectively;
• and
• a cylinder that is connected to a lever that is among the plurality of levers and corresponds to the stator vane row located at the first stage.

A modification method comprising the steps of:

• using, as a foundation, an existing axial-flow compressor that has variable stator vanes that are located only at a first stage, constitute a stator vane row and rotate around rotary shafts of the variable stator vanes so as to adjust angles of the variable stator vanes, the shafts extending in a radial direction of the axial-flow compressor;
• replacing at least stator vanes included in the existing axial-flow compressor and located at a second stage with other variable stator vanes;
• connecting a new ring to another stator vane row constituted by the other variable stator vanes so that the ring drives and rotates the other variable stator vanes of the other stator vane row;
• adding, to the existing axial-flow compressor, a plurality of levers, a new rotary shaft and a plurality of connecting rods, the plurality of levers corresponding to the ring and another ring that is located at the first stage, the new rotary shaft holding the plurality of levers so as to enable the levers to pivot, extending in an axis of the axial-flow compressor, and connecting the plurality of levers to each other so that the plurality of levers are fixed to the rotary shaft and integrated with each other through the rotary shaft, the connecting rods connecting the plurality of rings to the plurality of levers that correspond to the rings, respectively;
• and
• connecting a cylinder included in the existing axial-flow compressor to a lever that is among the plurality of levers and corresponds to the stator vane row located at the first stage, or connecting another cylinder whose class is the same as or similar to the cylinder included in the existing axial-flow compressor to the lever that is among the plurality of levers and corresponds to the stator vane row located at the first stage.