Hollow Power Transmission Shaft

Abstract

Provided is a hollow power transmission shaft exhibiting an increased strength when a pipe used as a material thereof is machined to make the pipe unlikely to crack during processing. A pipe (P) made of steel is normalized to improve its machinability as a raw material and obtain uniform strength. This can make the pipe unlikely to crack during splining and rolling.

1 . A hollow power transmission shaft, which is obtained by subjecting a pipe made of steel to deformation processing into a desired shape,
 wherein the pipe is normalized byway of heat treatment before being subjected to the deformation processing.   
   
   
       2 . A hollow power transmission shaft according to  claim 1 , wherein the pipe is swaged by way of the deformation processing. 
   
   
       3 . A hollow power transmission shaft according to  claim 1 , wherein the pipe is rolled by way of the deformation processing. 
   
   
       4 . A hollow power transmission shaft according to  claim 1 , wherein the pipe is swaged and then rolled by way of the deformation processing. 
   
   
       5 . A hollow power transmission shaft, which is obtained by swaging a pipe made of steel into a desired shape, and rolling the pipe to form splines at both ends thereof respectively,
 wherein the pipe is normalized by way of heat treatment before being swaged and rolled.