Application and modelling of flow forming manufacturing processes for internally geared wheels

The production of internally geared wheels by flow forming is a new process developed at the PtU Darmstadt. The technology enables manufacturing in one-piece design without additional machining operation. In this process, an externally geared mandrel is fitted into a cup-like work piece. By reducing the cup's outside diameter, the inner wall of the cup is rolled into the mandrel's teeth, thereby producing the gear's profile. Three tooling concepts with different kinematics and numbers of rolls were analyzed using experimental methods. Numerical analyses revealed several shortcomings of available finite-element codes to handle complex flow forming processes. The first step of an efficient computation is the development of a parameterized process model. This is able to act as a starting basis for a virtual product and process design.