Method of producing outer ring of self- alinging bearing

Abstract

To provide a method of producing an outer ring of a self-aligning bearing in which at a raceway-turning step after a heat treatment, the chipping of a turning tool and damage of a raceway can be prevented. Before the heat treatment, an annular groove 2 b is formed in that portion of the raceway 2 a of the outer ring 2 corresponding to lubrication holes 7 , thereby avoiding a situation in which a discontinuous cutting operation occurs because of the lubrication holes 7 at the raceway-turning step after the heat treatment.

1 . A method of producing an outer ring of a self-aligning bearing, comprising:
 a first turning step of turning an annular stock to form a blank having a predetermined machining allowance formed at a raceway;   a boring step of forming lubrication holes in said blank which lubrication holes are open to the raceway and an outer periphery of the blank;   a heat treatment step of hardening the blank, having said lubrication holes formed therein, to predetermined hardness; and   a second turning step of turning said raceway after the heat treatment step; characterized in that:   before said heat treatment step, a turning operation is applied to that portion of said raceway corresponding to the lubrication holes to form an annular groove for avoiding a situation in which a discontinuous cutting operation occurs at said second turning step because of said lubrication holes.   
   
   
       2 . A method of producing an outer ring of a self-aligning bearing, comprising:
 a first turning step of turning an annular stock to form a blank having a predetermined machining allowance formed at a raceway;   a boring step of forming lubrication holes in said blank which lubrication holes are open to the raceway and an outer periphery of the blank;   a heat treatment step of hardening the blank, having said lubrication holes formed therein, to predetermined hardness;   a second turning step of turning said raceway after the heat treatment step while leaving a grinding allowance; and   a grinding step of grinding the raceway for finishing purposes after the second turning step; characterized in that:   before said heat treatment step, a turning operation is applied to that portion of said raceway corresponding to the lubrication holes to form an annular groove for avoiding a situation in which a discontinuous cutting operation and a discontinuous   grinding operation occur respectively at said second turning step and said grinding step because of said lubrication holes.   
   
   
       3 . A method of producing an outer ring of a self-aligning bearing, comprising:
 a turning step of turning an annular stock to form a blank having a predetermined grinding allowance formed at a raceway;   a boring step of forming lubrication holes in said blank which lubrication holes are open to the raceway and an outer periphery of the blank;   a heat treatment step of hardening the blank, having said lubrication holes formed therein, to predetermined hardness; and   a grinding step of grinding the raceway for finishing purposes after the heat treatment step; characterized in that:   before said heat treatment step, a turning operation is applied to that portion of said raceway corresponding to the lubrication holes to form an annular groove for avoiding a situation in which a discontinuous grinding operation occurs at said grinding step because of said lubrication holes.