Rotor repair method and rotor repair apparatus

Abstract

A to-be-repaired damaged part, which occurs in a rotor, is removed and shaped by machining or grinding. The shaped surface, from which the to-be-repaired damaged part is removed in the step, is roughened by a blasting process. A coating is formed on the surface, which is roughened in the step, by a high-velocity flame spray apparatus. The coating, which is formed in the step, is finished by machining or polishing. A defect inspection is performed to check presence/absence of a defect. A dimensional/quality inspection is performed for the part repaired in the step.

1 . A rotor repair method wherein a thermal spray coating is formed on a to-be-repaired damaged part of a rotor, which is rotatably supported by a bearing, by a high-velocity flame spray apparatus with a flame velocity of 600 m/sec to 3000 m/sec and with a particle velocity of 500 m/sec to 2000 m/sec, whereby the damaged part is repaired.  
     
     
         2 . The rotor repair method according to  claim 1 , wherein when the thermal spray coating is formed on the damaged part of the rotor and the damaged part is repaired, a thermal spray repair material, which has a chemical composition and material characteristics similar to the damaged part of the rotor, is used.  
     
     
         3 . The rotor repair method according to  claim 1 , wherein when the thermal spray coating is formed on the damaged part of the rotor and the damaged part is repaired, the thermal spray coating in a range of 0.05 mm to 8.0 mm is formed on the to-be-repaired part of the rotor.  
     
     
         4 . The rotor repair method according to  claim 1 , wherein when the thermal spray coating is formed on the damaged part of the rotor and the damaged part is repaired, the to-be-repaired part is subjected in advance to a surface formation process by machining or grinding, and the to-be-repaired part is roughened by a blasting process.  
     
     
         5 . The rotor repair method according to  claim 4 , wherein when the to-be-repaired part is subjected to the surface formation process by machining or grinding, a shape of a groove at both ends of the repaired part is formed to have an inclined surface at 45° or less (excluding 0°) or an arcuate surface.  
     
     
         6 . The rotor repair method according to  claim 1 , wherein when the thermal spray coating is formed on the damaged part of the rotor and the damaged part is repaired, a surface of the formed coating is finished in advance to have a surface roughness of 6.5 S or less (excluding 0 S) by machining or polishing.  
     
     
         7 . The rotor repair method according to  claim 1 , wherein when the thermal spray coating is formed on the damaged part of the rotor and the damaged part is repaired, repair is performed at one of a location of a generation plant, in which the rotor is disposed, and a location of a repair factory, or at a location where the generation plant and the repair factory are disposed together.  
     
     
         8 . The rotor repair method according to  claim 1 , wherein when the thermal spray coating is formed on the damaged part of the rotor and the damaged part is repaired, thermal spray is performed by horizontally moving a thermal spray gun of the high-velocity flame spray apparatus while the rotor is being rotated.  
     
     
         9 . The rotor repair method according to  claim 1 , wherein when the thermal spray coating is formed on the damaged part of the rotor and the damaged part is repaired, repair is performed by fixing a thermal spray gun of the high-velocity flame spray apparatus to equipment capable of arbitrarily moving the thermal spray gun of the high-velocity flame spray apparatus in a horizontal direction and a perpendicular direction to a rotational axis of the rotor.  
     
     
         10 . The rotor repair method according to  claim 9 , wherein a robot or a driving mechanism including a ball screw and a stepping motor is used as the equipment capable of arbitrarily moving the thermal spray gun of the high-velocity flame spray apparatus in the horizontal direction and perpendicular direction.  
     
     
         11 . The rotor repair method according to  claim 10 , wherein when the thermal spray gun is moved in the horizontal direction and vertical direction to the rotational axis of the rotor, the movement is controlled with a movement speed of a pitch of 0.1 mm/sec.  
     
     
         12 . A rotor repair apparatus comprising: 
 a thermal spray unit including a thermal spray gun for forming a thermal spray coating on a to-be-repaired part of a rotor which is to be repaired, while rotating the rotor; and    a driving unit which moves the thermal spray gun in a horizontal direction or in a vertical direction to a rotational axis of the rotor at a movement speed with a pitch of 0.1 mm/sec.