Method for manufacturing shaft

A method for manufacturing a shaft in which linking members are provided to ends of a cylindrical member,

• the method being characterized by including:
• a polishing step for polishing end surfaces of a metal sheet to a surface roughness Ra of 2 μm or less;
• a bending step for bending the metal sheet into a semicylindrical shape;
• a diffusion-joining step for disposing a pair of the metal sheets that are bent into a semicylindrical shape so as to form a cylindrical shape and butting together the polished end surfaces of the metal sheets, and then heating the butted portions so that the butted portions are diffusion-joined, thereby forming the cylindrical member;
• a cooling step for cooling the post-diffusion-joining-step cylindrical member;
• a linking-member-joining step for joining the linking members to the ends of the cylindrical member;
• and
• an interior finishing step for cutting or polishing the inner surfaces of the butted portions of the post-diffusion-joining-step cylindrical member,
• in the diffusion-joining step, the parallel and horizontally disposed end surfaces of the pair of semicylindrical metal sheets being directly butted together, and the entireties of the end surfaces being diffusion-joined while pressurized so as to be pressed together in a direction orthogonal to the end surfaces.

A method for manufacturing a shaft in which linking members are provided to ends of a cylindrical member,

• the method being characterized by including:
• a polishing step for polishing end surfaces of a metal sheet;
• a bending step for bending the metal sheet into a semicylindrical shape;
• a diffusion-joining step for disposing a pair of the metal sheets that are bent into a semicylindrical shape so as to form a cylindrical shape and butting together the polished end surfaces of the metal sheets, and then heating the butted portions so that the butted portions are diffusion-joined, thereby forming the cylindrical member;
• a cooling step for cooling the post-diffusion-joining-step cylindrical member;
• and
• a linking-member-joining step for joining the linking members to ends of the cylindrical member through friction welding or shrink-fitting during the cooling step,
• in the diffusion-joining step, the parallel and horizontally disposed end surfaces of the pair of semicylindrical metal sheets being butted together, and the entireties of the end surfaces being diffusion-joined while pressurized so as to be pressed together in a direction orthogonal to the end surfaces.