Study On The Quality Of Tooth Profile Of Involute Spur Cylindrical Gear Shaft Formed By Cross Wedge Rolling

Not only the processing efficiency and utilization of material but also the strength of the product will be improved if the gear shaft was produced by cross wedge rolling (CWR). The tooth profile plays an important part to the quality of the gear shaft. Thus, the main content of this paper is focused on revealing how various factors affect the quality of the tooth profile on involute spur cylindrical gear shaft. The research has the theoretical significance and engineering value for application.First, Triangular velocity field, a theory in upper bound method, was used to analyze the forming of gear part during the process of involute spur cylindrical gear shaft by cross wedge rolling based on the plane strain assumption and symmetric deformation in material assumption. The formulas of average relative pressure in unit on the workpiece and the power need to roll were studied and the results show that the average relative pressure in unit increases with the growing of the modulus and the tooth number of gear shaft.Then, the assembled die for a particular gear shaft was designed and simulations on the process of a particular gear shaft by CWR were carried out in Deform. The defects such as difficulty in rotating, slip of the workpiece, disorder of the teeth, material deficiency on teeth and at the two sides of gear part during the simulation were solved by modifying the dies and some parameters after analyzed the mechanisms of defects forming. The quality of tooth profile of the formed gear shaft and the force state of dies and blocks during the CWR process was analyzed.At last, the impact of the temperature of the workpiece, the number of the gear, modulus and the velocity of the die movement on the quality of tooth profile and the maximum value of force on dies during CWR process was studied and the best combination of produce conditions were found.