Method for the production of hollow shafts with a profile

摘要

Method for the production of a hollow shaft with end portions and a central portion which is enlarged radially relative to the latter in relation to the axis of the shaft from a tube of constant diameter. For this purpose, the tube is placed in a die which has a cavity with an internal longitudinal profile having retaining regions for the end portions and with an expansion region, situated between the retaining regions, for the central portion of the hollow shaft. The tube is then subjected internally to hydraulic pressure at least in the portion provided for the central portion of the hollow shaft until the outer surface of the tube comes to rest against the inner surface of the cavity of the die. In this method, the material is weakened before radial expansion in an axially central region of the tube portion intended for the central portion of the hollow shaft, which tube portion is to be expanded. <IMAGE>