High carbon steel formed bearing assembly

Abstract

A roller bearing assembly and a method of forming a rolling bearing assembly. The bearing assembly includes a shell formed from a cold-rolled strip having a carbon content greater than 0.65%. In one aspect of the invention, the circumferential raceway has an as hardened surface hardness of at least 58 HRC without the application of a carburizing treatment to the formed shell. In another aspect of the invention, the cold-rolled strip has a carbon content greater than 0.65% and an ASTM grain size no. of 8 or finer. The circumferential raceway has an average surface roughness Ra less than or equal to 18 microinchs without the application of any finishing process to the formed shell.

1 . A method of forming a rolling bearing component comprising the steps of: 
 providing a cold-rolled strip having a carbon content greater than 0.65%;    forming the strip to form a shell having a circumferential raceway; and    positioning a plurality of rolling elements in the shell;    wherein the circumferential raceway has an as hardened surface hardness of at least 58 HRC without applying a carburizing treatment of the formed shell.    
   
   
       2 . The method according to  claim 1  wherein the forming step includes deep drawing, stamping, cold forming or a combination thereof of the cold-rolled strip.  
   
   
       3 . The method according to  claim 1  wherein the cold-rolled strip has an ASTM grain size no. of 8 or finer.  
   
   
       4 . The method according to  claim 3  wherein the circumferential raceway has a surface roughness Ra less than or equal to 18 microinchs without the application of any finishing process to the formed shell.  
   
   
       5 . The method according to  claim 1  wherein the cold-rolled strip has a plain strain forming limit value (FL 0 ) greater than or equal to 0.25.  
   
   
       6 . A method of forming a rolling bearing component comprising the steps of: 
 providing a cold-rolled strip having a carbon content greater than 0.65% and an ASTM grain size no. of 8 or finer;    forming the strip to form a shell having a circumferential raceway; and    positioning a plurality of rolling elements in the shell.    
   
   
       7 . The method according to  claim 6  wherein the circumferential raceway has a surface roughness Ra less than or equal to 18 microinchs without the application of any finishing process to the formed shell.  
   
   
       8 . The method according to  claim 6  wherein the forming step includes deep drawing, stamping, cold forming or a combination thereof of the cold-rolled strip.  
   
   
       9 . The method according to  claim 6  wherein the circumferential raceway has an as hardened surface hardness of at least 58 HRC without applying a carburizing treatment of the formed shell.  
   
   
       10 . The method according to  claim 6  wherein the cold-rolled strip has a plain strain forming limit value (FL 0 ) greater than or equal to 0.25.  
   
   
       11 . A method of forming a rolling bearing component comprising the steps of: 
 providing a cold-rolled strip having a carbon content greater than 0.65% and a plain strain forming limit value (FL 0 ) greater than or equal to 0.25;    forming the strip to form a shell having a circumferential raceway; and    positioning a plurality of rolling elements in the shell.    
   
   
       12 . The method according to  claim 11  wherein the forming step includes deep drawing, stamping, cold forming or a combination thereof of the cold-rolled strip.  
   
   
       13 . The method according to  claim 11  wherein the cold-rolled strip has an ASTM grain size no. of 8 or finer.  
   
   
       14 . The method according to  claim 13  wherein the circumferential raceway has a surface roughness Ra less than or equal to 18 microinchs without the application of any finishing process to the formed shell.  
   
   
       15 . The method according to  claim 11  wherein the circumferential raceway has an as hardened surface hardness of at least 58 HRC without applying a carburizing treatment of the formed shell.  
   
   
       16 . A rolling bearing assembly manufactured by the process comprising the steps of: 
 providing a cold-rolled strip having a carbon content greater than 0.65%;    forming the strip to form a shell having a circumferential raceway; and    positioning a plurality of rolling elements in the shell;    wherein the circumferential raceway has an as hardened surface hardness of at least 58 HRC without applying a carburizing treatment of the formed shell.    
   
   
       17 . A rolling bearing according to  claim 16  wherein the shell has a cross-section with a substantially uniform carbon content without applying a carburizing treatment to the formed shell.  
   
   
       18 . A rolling bearing assembly manufactured by the process comprising the steps of: 
 providing a cold-rolled strip having a carbon content greater than 0.65% and an ASTM grain size no. of 8 or finer;    forming the strip to form a shell having a circumferential raceway; and    positioning a plurality of rolling elements in the shell.    
   
   
       19 . The rolling bearing assembly of  claim 17  wherein the circumferential raceway has a surface roughness Ra less than or equal to 18 microinchs without the application of any finishing process to the formed shell.  
   
   
       20 . A rolling bearing assembly manufactured by the process comprising the steps of: 
 providing a cold-rolled strip having a carbon content greater than 0.65% and a plain strain forming limit value (FL 0 ) greater than or equal to 0.25;    forming the strip to form a shell having a circumferential raceway; and    positioning a plurality of rolling elements in the shell.