Tool Profile Generation by Boolean Operations on Ball Nuts

Abstract:

Ballscrew drive mechanisms are widely used in the transmitting system of precision machine tools. The profile of the ball nut is a gothic curve combined by two equal radius arcs with offset centers. Most of gothic arc ball nuts are manufactured by form grinding, where the grinding wheel is shaped into the desired profile and the tool axis is tilted at the lead angle of the ball nut thread. In case of the internal ball nut grinding the high lead angle and long thread limits the manufacturing process. To avoid the collision between the internal surface of the workpiece and outer surface of the quill the optimal tilt angle is modified. The modified tilt angle affects to the profile of the formed grinding wheel. This paper presents a method for the generation of modified grinding wheel profile independently the tilt angle. The desired profile points are generated by solid boolean operations with programming of a parametric CAD system.

• Periodical: Key Engineering Materials (Volume 581)
• Pages: 462-465
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.581.462
• Online since: October 2013
• Authors: György Hegedűs, György Takács
• Keywords: Ball Nut, Boolean Operation, CAD, Curve, Generation, Tool Profile

References

[1] Harada H., Kagiwada T.: Grinding of high-lead and gothic-arc profile ball-nuts with free quill-inclination, Precision Engineering 28 (2004), pp.143-151.

DOI: 10.1016/j.precisioneng.2003.07.003

[2] Guevarra D. S., Kyusojin A., Isobe H., Kaneko Y.: Development of a new lapping method for high precision ball screw (1st report) – feasibility study of a prototyped lapping tool for automatic lapping process, Precision Engineering Journal of the International Societies for Precision Engineering and Nanotechnology 25 (2001).

DOI: 10.1016/s0141-6359(00)00059-3

[3] Dudás L.: New way for the innovation of gear types, Engineering the Future, Chapt. 6. Sciyo, Croatia, 2010, ISBN 978-953-307-210-4 pp.111-140.

[4] F. L. Litvin, A. Fuentes: Gear Geometry and Applied Theory – Second Edition, Cambridge University Press, 2004, ISBN 978-052-181-517-8.

[5] V. Ivanov, G. Nankov, V. Kirov: CAD orientated mathematical model for determination of profile helical surfaces, International Journal of Machine Tools and Manufacture, 38 (8) (1998), p.1001–1015.

DOI: 10.1016/s0890-6955(98)00002-9

[6] S. K. Kang, K. F. Ehmann, C. Lin: A CAD approach to helical groove machining—I. mathematical model and model solution, International Journal of Machine Tools and Manufacture, 36 (1) (1996), p.141–153.

DOI: 10.1016/0890-6955(95)92631-8

[7] S. K. Kang, K. F. Ehmann, C. Lin: A CAD approach to helical groove machining. Part 2: Numerical evaluation and sensitivity analysis, International Journal of Machine Tools and Manufacture, 37 (1) (1997), p.101–117.

DOI: 10.1016/0890-6955(95)00039-9

[8] L. V. Mohan, M. S. Shunmugam: CAD approach for simulation of generation machining and identification of contact lines, International Journal of Machine Tools and Manufacture, 44 (7–8) (2004), p.717–723.

DOI: 10.1016/j.ijmachtools.2004.02.013

[9] R. Hal, J. Flusser: Numerically stable direct least squares fitting of ellipses, The 6th International Conference in Central Europe on Computer Graphics and Visualization, 21 (5), 1998, pp.59-108.