Saint Petersburg State Polytechnical University, Saint Petersburg, Russia:

Aksenov L. B., Professor, e-mail: l_axenov@mail.spbstu.ru
Kunkin S. N., Head of a Chair

This article presents the results of development of machines and processes of axial rotary forging (considerably different from traditional) at Saint Petersburg State Polytechnical University. The rotary forging processes occupy an important place among the metal forming technologies because of many advantages, such as: reduced forming force, increased tool life, fewer investments in equipment etc. Technological potential of rotary forging may be extended with new ways of transmitting deforming force from the tool to the work-piece; different types of deforming tool; and kinematics of tool action on deformed metal. Rotary movement of the work-piece is driven by machines, while forging roll is driven by work-piece due to friction. This article presents the processes of rotary forging with two types of forging rolls: conical roll with inclination angle of ~15º and cylindrical roll with inclination angle of 90º. There was established that conical roll is preferable for shaping of internal surfaces and formation of parts from bar stock. Cylindrical rolls are preferred for formation of outer surfaces and large parts. Comparison of axial rotary forging with orbital forming showed the possibility of rotary forging of parts with force of 3–4 times lower, than orbital forging with roll inclination angle of 2–3º. Developed CAD system allows to choose both the scheme of technological process, and determination of processing modes and tool and formed parts' geometry. The developed technologies of rotary forging may be applied for production of circular parts from pressed, rolled and welded tubes, and for production of ring work-pieces from compact and powder materials.

1. Ekonomichnye metody formoobrazovaniya detaley (Economical methods of details' shaping). Under the editorship of K. N. Bogoyavlenskiy and V. V. Ris. Leningrad : Lenizdat, 1984. 144 p.
2. Surkov V. A., Koryakin N. A. Zagotovitelnye proizvodstva v mashinostroenii — Procurement productions in mechanical engineering. 2008. No. 7. pp. 21–28.
3. Orbitform Group. Available at : www.orbitform.com. (accessed: October 24, 2013).
4. Aksenov L. B., Elkin N. M., Kunkin S. N. Metalloobrabotka — Metalworking. 2011. No. 3 (63). pp. 31–36.
5. Munshi M., Shah K., Cho H., Altan T. Finite element analysis of orbital forming used in spindle/inner ring assembly. 8^th ICTP 2005 — International Conference on Technology of Plasticity, Verona, October 9–13^th 2005.