Method of manufacturing supercharger

A method of manufacturing a supercharger including a turbine configured to rotationally drive, and a compressor having an impeller configured to rotate according to rotational force of the turbine and a housing configured to store the impeller, the method comprising:

• a process of applying coating of an abradable material which is to form an abradable layer when being solidified, only to a predetermined range on a surface, the surface being either one of surfaces of the impeller and the housing via which the impeller and the housing face;
• and before the process of applying coating of the abradable material, a process of increasing a roughness degree in an outer range to which coating of the abradable material is not applied, the outer range being directly adjacent to the predetermined range, to be rougher than a roughness degree in the predetermined range, on either one of the surfaces of the impeller and the housing, wherein a region to which coating of the abradable material is applied and a region to which coating of the abradable material is not applied are on the same continuous surface.

A method of manufacturing a supercharger including a turbine configured to rotationally drive, and a compressor having an impeller configured to rotate according to rotational force of the turbine and a housing configured to store the impeller, the method comprising:

• a process of applying coating of an abradable material which is to form an abradable layer when being solidified, only to a predetermined range on either one of surfaces of the impeller and the housing via which the impeller and the housing face, without applying masking, and before the process of applying coating of the abradable material, a process of forming a recess portion to separate either one of the surfaces of the impeller and the housing into the predetermined range and an outer range to which coating of the abradable material is not applied, the recess portion being directly adjacent to each of the outer range and the predetermined range, wherein either one of the surfaces is a smoothly continuous surface before the recess portion is formed.