Bearing processing method, and bearing processing apparatus

Abstract

The processing method of the grooves and the processing apparatus of the present invention do not utilize the elastic deformation of a bearing itself, and by inserting the pin into the cylindrical-shaped core rod which is inserted into the inner circumference of the cylindrical-shaped bearing material, the cylindrical-shaped core rod is depressed against the inner circumference surface of the cylindrical-shaped bearing material and the concavoconvex of the outer circumference of the cylindrical-shaped core rod is transfer-printed on the inner circumference of the cylindrical-shaped bearing material.

1 . A bearing processing method comprising the steps of: 
 inserting a cylindrical-shaped core rod having grooves on an outer circumference surface in a cylindrical-shaped bearing material;    elastically deforming the cylindrical-shaped core rod in the radial direction by forcedly inserting a pin inside of the cylindrical-shaped core rod while holding the cylindrical-shaped bearing material so as not to expand in the radial direction; and    transfer-printing the grooves on the inner circumference surface of the bearing material to form a bearing.    
   
   
       2 . The bearing processing method as cited in  claim 1 , wherein; 
 said bearing is a hydrodynamic bearing; and    said grooves are concave grooves formed on inner circumference surface of the hydrodynamic bearing.    
   
   
       3 . A bearing processing apparatus comprising: 
 a cylindrical-shaped core rod for holding a cylindrical-shaped bearing material and being formed with predetermined grooves on an outer circumference surface;    a sleeve for preventing the cylindrical-shaped bearing material from being expanded in the radial direction; and    a pin having a lager diameter than the inside diameter of the cylindrical-shaped core rod and being inserted into a cylinder of the cylindrical-shaped core rod, wherein;    the diameter of the cylindrical-shaped core rod is expanded due to the elastic deformation by forcedly inserting the pin into the cylinder, and the grooves are transfer-printed on the inner circumference surface of the bearing material to form a bearing.    
   
   
       4 . The bearing processing apparatus as cited in  claim 3 , wherein; 
 said bearing is a hydrodynamic bearing; and    said grooves are concave grooves formed on inner circumference surface of the hydrodynamic bearing.    
   
   
       5 . The bearing processing apparatus as cited in  claim 3 , wherein; 
 the core rod comprises an integrally formed cylinder-shaped base portion and a major portion;    an outside diameter of the base portion is slightly larger than an outside diameter of the cylindrical-shaped bearing material to be attached to the major portion;    an outside diameter of the major portion is slightly smaller than an inner circumference diameter of the cylindrical-shaped bearing material; and    an inside diameter of the sleeve is slightly larger than the outside diameter of the base portion in the cylindrical-shaped core rod.