MECHANICAL ELEMENT HAVING PRESSED SHAFT INTO FITTING MEMBER AND MANUFACTURE THEREOF

摘要

PURPOSE:To prevent cracking of a cam piece at the time of press-in, reduce the occurrence of chips and enhance the jointing strength between a fitting member and a shaft, in a cam shaft which has a sintered alloy cam piece pressed and fitted into a protrusion portion formed on the outer periphery of a shaft and has it assembled into an integral assembly. CONSTITUTION:A low carbon steel inner piece 2 is fitted into a sintered alloy hollow fitting member 1. In a shaft hole 20 of the inner piece, there are disposed a large diameter portion and a small diameter portion. A protrusion portion 4 of a shaft 3 is harder than the inner piece 2. The outer diameter D1 thereof is larger than the inner diameter of the small diameter portion and smaller than the outer diameter of the inner piece 2, preferably smaller than the inner diameter of the large diameter portion. Fit jointing of both is thus made by pressing filling of the protrusion 4 into the shaft hole 20 and deforming the former.