Variable height modification of TA worm drive

Abstract

The related research shows that a constant contact line, which is negative for the normal operation of the worm gearing, exists on the middle of the unmodified and the constant height modified TA worm wheel surface. To overcome this drawback, a variable height modification method is proposed for the TA worm drive. In line with this modification method, the height modification parameter is variable during the whole processing cycle. Accordingly, the obtained gearing can be named as the variable height modified TA worm drive. The mathematical model for the meshing analysis of this novel worm drive is established according to its generation mechanism and the mesh theory of gearing. The reason why the variable height modification can remove the constant contact line on the worm gear tooth surface is analyzed in detail. In addition, the classification criterion of the transmission type is also derived. The computing methods of the key points on the contact zone boundary and the instantaneous meshing line are elaborated. On the basis of the above theoretical analysis, the meshing characteristics of this novel worm gearing are well investigated. The results manifest that the above theoretical analysis is valid, and the obtained gearing has favorable meshing properties. Furthermore, it is pointed out that the linear variable height modification with larger quantity can be recommended as the ideal strategy in practice.

Keywords

Globoidal worm height modification meshing analysis contact line meshing characteristics

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References

Buckingham

. Analytical mechanics of gear, 3rd ed. New York: Dover Publications, Inc., 1988.

Crosher

. Design and application of the worm gear, New York: ASME Press, 2002.

Dudás

. The theory and practice of worm gear drives, London: Penton Press, 2000.

Chen Y, et al. Development and classification of worm drive. In: Proceedings of the 14th IFToMM world congress, Taipei, Taiwan, 25–30 October 2015.

Dudley

. Gear handbook: the design, manufacture, and application of gears, New York: McGraw-Hill, 1962.

Mohan

Shunmugam

. Geometrical aspects of double enveloping worm gear drive. Mech Mach Theory 2009; 44: 2053–17.

Zhao Y, et al. Advances in the research of hourglass worm drives. In: Proceedings of international symposium “Theory and practice of gearing”, Izhevsk, Russia, 21–23 January 2014.

et al.

Worm drives design, Beijing: China Machine Press, 1987.

et al.

Design of worm drives 1987; vol. 2. Beijing: China Machine Press.

10.

Litvin

et al.

Gear geometry and applied theory, 2nd ed. UK: Cambridge University Press, 2004.

11.

Luo

. Meshing theory for gear drives, Beijing: Science Press, 1985.

12.

Chen

. Meshing theory for gear drives, Beijing: Coal Industry Press, 1986.

13.

. Spatial meshing theory and its application, Beijing: Coal Industry Press, 1987.

14.

Zhao

et al.

Novel types of worm drive, Xi’an: Shaanxi Science and Technology Press, 1990.

15.

Dong

. Design and modification of hourglass worm drives, Beijing: Mechanical Industry Press, 2004.

16.

Zhou

. Modification principle and manufacture technology for hourglass worm drives, Changsha: National University of Defense Technology Press, 2005.

17.

Zhao

et al.

Computer aided analysis on the meshing behavior of a height-modified dual-torus double-enveloping toroidal worm drive. Comput Aided Des 2010; 42: 1232–1240.

18.

Wardle

. Differential geometry, New York: Dover Publications, Inc., 2008.

19.

Zhao

et al.

Novel methods for curvature analysis and their application to TA worm. Mech Mach Theory 2016; 97: 155–170.

20.

Dong

. Meshing theory foundation of gearing, Beijing: China Machine Press, 1989.

21.

Zhu

et al.

Analysis of load capacity of gears, Beijing: Higher Education Press, 1992.

22.

Zhao

et al.

Tooth flank modification theory of dual-torus double-enveloping hourglass worm drives. Comput Aided Des 2011; 43: 1535–1544.

23.

Zhao Y. Meshing analysis for TA worm drive. In: Proceedings of EUCOMES 2016, Nantes, France, 20–23 September 2016.