Axial force controlling method and bearing apparatus

Abstract

In a bearing apparatus having a bearing and a shaft body, the bearing being mounted to the shaft body such that the bearing fits an outside of the shaft body, the bearing being prevented from dropping off by holding a caulked portion against an outer end face of an inner ring of the bearing, and the caulked portion being formed by bending a cylindrical portion to be caulked of the shaft body outward in a diameter direction, an axial force controlling method controls an axial force applied to the bearing through the caulked portion by setting a relationship between relative positions in an axial direction of an end edge on an inner periphery side of a chamfered portion formed at an inner peripheral shoulder portion of the inner ring and a caulking starting point on an inner periphery side of a cylindrical portion to be caulked.

What is claimed is:  
     
         1 . An axial force controlling method for controlling an axial force applied to a rolling bearing in a bearing apparatus having said rolling bearing and a shaft body, said rolling bearing being mounted to said shaft body such that said rolling bearing fits an outside of said shaft body, said rolling bearing being prevented from dropping off by holding a caulked portion against an outer end face of an inner ring of said rolling bearing, and said caulked portion being formed by bending a cylindrical portion to be caulked on a free end side of said shaft body outward in a diameter direction, wherein said method comprises the following steps for controlling said axial force applied to said rolling bearing through said caulked portion: a first step of setting a position (first position) of an end edge on an inner periphery side of a chamfered portion formed at an inner peripheral shoulder portion of said inner ring; and a second step of setting a relationship between relative positions on an axial direction of said first position and a position (second position) of a caulking starting point on an inner periphery side of said cylindrical portion to be caulked.  
     
     
         2 . An axial force controlling method according to  claim 1 , wherein said second step is a step of positioning said second position on an axially outside with respect to said first position.  
     
     
         3 . An axial force controlling method according to claim  1 , wherein said second step is a step of axially aligning said second position with respect to said first position.  
     
     
         4 . An axial force controlling method according to  claim 1 , wherein said second step is a step of positioning said second position on an axially inside with respect to said first position.  
     
     
         5 . An axial force controlling method according to  claim 1  further including a third step of setting a radial thickness of said cylindrical portion to be caulked.  
     
     
         6 . An axial force controlling method according to  claim 1  further including a fourth step of setting a hardness of said cylindrical portion to be caulked.  
     
     
         7 . An axial force controlling method according to  claim 1 , wherein said second step is a step of obtaining an axial force greater than a required axial force by plotting said axial direction in a one-dimensional coordinate, defining said first position as an origin point of said one-dimensional coordinate, setting a range of a permissible position to which said second position can be moved away from said first position at least one of axially inward or outward according to said required axial force, and setting said relationship between relative positions in said axial direction of said first position and said second position in said range.  
     
     
         8 . A bearing apparatus comprising: 
 a rolling bearing; and    a shaft body, said rolling bearing being mounted to said shaft body such that said rolling bearing fits an outside of said shaft body and said shaft body having a cylindrical portion to be caulked on a free end side of said shaft body,    wherein said cylindrical portion to be caulked of said shaft body is bent outward in a diameter direction onto an outer end face of an inner ring to form a caulked portion in a state in which a relationship between relative positions in an axial direction of a caulking starting point on an inner periphery side of said cylindrical portion and an end edge on an inner periphery side of a chamfered portion formed at an inner peripheral shoulder portion of said inner ring of said rolling bearing, and    an axial force is applied to said rolling bearing through said caulked portion.