Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30831
On the Efficiency of a Double-Cone Gravitational Motor and Generator

Authors: Barenten Suciu, Akio Miyamura


In this paper, following the study-case of an inclined plane gravitational machine, efficiency of a double-cone gravitational motor and generator is evaluated. Two types of efficiency ratios, called translational efficiency and rotational efficiency, are defined relative to the intended duty of the gravitational machine, which can be either the production of translational kinetic energy, or rotational kinetic energy. One proved that, for pure rolling movement of the double- cone, in the absence of rolling friction, the total mechanical energy is conserved. In such circumstances, as the motion of the double-cone progresses along rails, the translational efficiency decreases and the rotational efficiency increases, in such way that sum of the rotational and translational efficiencies remains unchanged and equal to 1. Results obtained allow a comparison of the gravitational machine with other types of motor-generators, in terms of the achievable efficiency.

Keywords: Efficiency, friction, Truncated double-cone, rolling and sliding, gravitational motor and generator

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 508


[1] A. A. Gallitto, and E. Fiordilino, “The Double Cone: A Mechanical Paradox or a Geometrical Constraint?,” Physics Education, 46, pp. 682–684, 2011.
[2] S.C. Gandhi, and C.J. Efthimiou, “The Ascending Double-Cone: A Closer Look at a Familiar Demonstration,” European Journal of Physics, 26, pp. 681–697, 2005.
[3] N. Balta, “New Versions of the Rolling Double Cone,” Physics Teacher, 40, pp. 156–157, 2002.
[4] B. Suciu, “On the Kinematics of a Double-Cone Gravitational Motor,” International Journal of Science and Engineering Investigations, 5(53), pp. 1–7, 2016.
[5] B. Suciu, “Frictional Effects on the Dynamics of a Truncated Double- Cone Gravitational Motor,” International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, Vol. 11(1), pp. 28–38, 2017.
[6] B. Suciu, “Solution to the Problem of Contact between a Double-Cone and Two Eccentric Circular Rails used in the Construction of a Wave-Powered Electrical Generator,” Transactions of the JSME, 83(853), pp. 1–12, 2017 (in Japanese).
[7] G.W. Stachowiak, and A.W. Batchelor, Engineering Tribology. 3rd ed., London: Elsevier, 2005, pp. 287–362, 461–499.
[8] R.K. Rajput, A Textbook of Applied Mechanics. 3rd ed., New Delhi: Laxmi Publications, 2001, pp. 187–262.
[9] C.H. Haswell, Engineers’ and Mechanics’ Pocket Book. New York: Harper & Brothers, 1844, pp. 67–83.
[10] D. Murdock, Worked Examples from Introductory Physics. Part 1: Basic Mechanics. Tennessee: Technological University, 2005, pp. 85–95.
[11] A. Domenech, T. Domenech, and J. Cebrian, “Introduction to the Study of Rolling Friction,” American Journal of Physics, 55(3), pp. 231–235, 1987.