Method of manufacturing hollow member

Abstract

A washer is provided between two inner rings arranged in a row, and annular washers are disposed outside the inner rings in the axial direction of the inner ring, respectively. A bolt is inserted into the two inner rings so that a head part of the bolt comes in contact with the washer disposed outside one inner ring in the axial direction of the inner ring. A nut is fastened on an end of the bolt opposite to the head part, from the outside of the washer. The inside of the through holes of the inner rings is substantially completely isolated from the outside thereof. The inner rings of which the inside of the through holes is substantially completely isolated from the outside are exposed to a carburizing atmosphere at high temperature, so as to perform carburizing and quenching only on the outer surfaces of the inner rings.

1 . A method of manufacturing a hollow member, the method comprising: 
 preparing at least one hollow member including a hole;    preparing an insertion member including a shaft part and a head part;    preparing a fastening member;    isolating an inside of the hole of the at least one hollow member from the outside by inserting the insertion member into the hole and fastening the fastening member on the shaft part protruding from the hole so that the at least one hollow member is fastened by the head part and the fastening member; and    performing a specific treatment on an outer surface of the at least one hollow member by exposing the at least one hollow members, in which the inside of the holes is isolated from the outside, to a treatment atmosphere.    
     
     
         2 . The method according to  claim 1 , wherein, in the isolating step, the at least one hollow member is fastened by the head part and the fastening member so that a washer is provided in at least one of a gap between the head part of the insertion member and an end face of the hollow member adjacent to the head part and a gap between the fastening member and an end face of the hollow member adjacent to the fastening member.  
     
     
         3 . The method according to  claim 2 , wherein a coefficient of linear expansion of the washer is larger than that of any one of the hollow members, the insertion member, and the fastening member.  
     
     
         4 . The method according to  claim 1 , wherein an inner periphery of the at least one hollow member includes at least one of a groove, a step, and a thread.