Rotor component with surfaces for checking concentricity

1. A rotor component for a rotor assembly of a fluid energy machine,

wherein the rotor component is at least partly made of a material susceptible to corrosion and/or oxidation and is arranged concentrically to a rotation axis of the rotor assembly,

wherein the rotor component comprises:

a circular surface for checking concentricity of the rotor component with respect to the rotation axis, and

at least one additional circular surface for checking concentricity of the rotor component with respect to the rotation axis,

wherein the additional circular surface is coated with a corrosion and/or oxidation protection coating,

wherein the circular surface and the at least one additional circular surface comprise the material susceptible to corrosion and/or oxidation.

2. The rotor component according to claim 1 ,

wherein the diameter of the additional circular surface differs from the diameter of the circular surface.

3. The rotor component according to claim 2 ,

wherein the diameter of the additional circular surface is less than the diameter of the circular surface.

4. The rotor component according to claim 1 ,

wherein the rotor component is a rotor disc for coupling a rotor platform of the rotor assembly to a rotor shaft of the rotor assembly.

5. The rotor component according to claim 1 ,

wherein the material susceptible to corrosion and/or oxidation is any one of a group comprising a carbon steel, a low carbon steel, a predominantly ferrous material or ferrous alloy which has less than 11% Chrome content, and aluminium.

6. A rotor assembly for a fluid energy machine comprising a gas turbine, a steam turbine, or a compressor, the rotor assembly comprising:

at least one rotor component according to claim 1 .

7. A fluid energy machine comprising a gas turbine, a steam turbine, or a compressor, the fluid energy machine comprising:

at least one rotor assembly according to claim 6 .

8. A method for manufacturing of a rotor component for a rotor assembly of a fluid energy machine comprising:

providing a blank body made at least partly of a material susceptible to corrosion and/or oxidation;

forming a circular surface for checking concentricity of the rotor component with respect a rotation axis of the rotor assembly, the circular surface comprises the material susceptible to corrosion and/or oxidation;

forming at least one additional circular surface for checking concentricity of the rotor component with respect to the rotation axis, the at least one additional circular surface comprises the material susceptible to corrosion and/or oxidation; and

coating the additional circular surface with a corrosion and/or oxidation protection coating.

9. The method according to claim 8 ,

wherein the additional circular surfaced is formed such that the diameter of the additional circular surface differs from the diameter of the circular surface.

10. The method according to claim 9 ,

wherein the additional circular surfaced is formed such that the diameter of the additional circular surface is less than the diameter of the circular surface.

11. The method according to claim 8 ,

wherein carbon steel is used as material susceptible to corrosion and/or oxidation.

12. A method for checking the concentricity of a rotor component according to claim 1 with respect to a rotation axis of a rotor assembly of a fluid energy machine, after use of the rotor component, the method comprising:

removing the corrosion and/or oxidation protection coating from the additional circular surface; and

checking the concentricity of the rotor component with respect to the rotation axis.

13. The method according to claim 12 ,

wherein the concentricity of the rotor component with respect to a rotation axis is checked using an indicator device.