Design and simulation of cross wedge rolling process for hollow motor shaft

Abstract. Nowadays, electric cars are experiencing rapid development, in which the production of motor shaft is one of the important parts. The cross wedge rolling (CWR) process is expected to be an efficient and material-saving production method for motor shaft production. Traditional motor shafts are manufactured by forging and machining, which inevitably causes material waste. While using the CWR method to produce the motor shaft, the forming accuracy can be improved, keeping the material performance. It’s possible to manufacture the hollow motor shaft billet directly and reducing the production cost greatly. Because of the asymmetric geometry profile of the motor shaft, the force is unbalanced during the forming process. The thermo-mechanical coupling finite element simulation is used to design and optimize the flat CWR tools. Then, the distribution of stress, strain, damage and temperature during the CWR process are analyzed. The traditional CWR process will easily cause central defects of the shaft such as micropores and voids. The hollow billet is used in the study. It helps to avoid such defects, also can be a new method to deal with the hollow motor shafts by CWR. Some disadvantages of traditional manufacture can be overcome.