Abstract: Cold rolling precision forming process of spline is one of the high-efficiency, precision and non-chip advanced manufacturing technologies. It has the characteristics such as high forming efficiency, energy-saving, low material consumption and better forming properties of components. The process and principle of involute spline is analyzed, the unit average pressure contacting area, rolling billet diameter, rolling force and moment are solved. Experiments of the cold rolling precision forming on involute spline are carried out. Experimental results show that dramatic plastic deformation takes place on the upper surface of the workpiece during the cold rolling process of spline, while the influence on the inner materials are very small. The grains are distributed as a flow line pattern along the tooth profile, and the grains in the plastic deformation zone present a fine and long fibrous state. The hardness on the section of the tooth outline is regularly distributed. Compared with the spline components obtained from conventional cutting method, the hardness of the spline is greatly increased, therefore, comprehensive mechanical property such as wear resistance and impact resistance are greatly improved. It can be shown from the precision measuring and hardness testing of the tooth outline section that the components obtained by the experiments are free of defects, and the application requirement can be satisfied.

Key words: Cold rolling, Forming process, Precision forming, Spline, CF units, electromagnetic drive, Finite Element Analysis (FEA)