1. Choi J C, Choi Y, Tak S J. The forging of helical gears. I. Experiments and upper-bound analysis [J]. International Journal of Mechanical Sciences, 1997, 40(4): 325–337.
2. Chen Fu-xiao, Jang Kai-yu, Yang Yong-shun, et al. Numerical simulation of deformation force laws during radial exrusion of cylindrical gear [J]. China Mechanical Engineering, 1998, 9(9): 12–14 (in Chinese).
3. Shadeghi M H. Gear forging: Mathematical modeling and experimental validation [J]. Journal of Manufacturing Science and Engineering, 2003, 125(4): 753–762.
4. Zhang Q P, Shang Y, Zhao G Q, et al. Numerical simulation of analysis parameters in precision vorging of spur gears [J]. China Mechanical Engineering, 2004, 15(17): 1546–1548 (in Chinese).
5. Gao X, Lü M, Li H B. UBET simulation of precision forging for spur gears [J]. Metal Forming Technology, 1996, 14(3): 21–23 (in Chinese).