Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2016
Date : August 23, 2016 - August 26, 2016
In this work the dynamic characteristics of a double-cone, self-propelled on a straight V-shape horizontal rail, are evaluated. Such simple mechanism can be regarded as a gravitational motor, which transforms the input potential energy into kinetic energy, of rotation and translation. Movies of the freely rolling double-cones, made of carbon steel and wood, against V-shape horizontal rails, made of aluminum alloy, were taken for various opening angles of the rails. Number of rotations, the variable rotation period, and the total traveling times of the double-cones were determined through the slow motion processing of taken movies. Several theoretical models were proposed and validated against the experimental results. One proved that the Hertzian contact point moves on the conical surface along a logarithmic spiral. Based on the proposed dynamical model, the traction force and the traction torque acting on the double-cone were identified. One proved that the traction force is always smaller than the translation friction force. However, the double-cone is able to self-propel on the rails if the traction torque exceeds the rolling friction torque. Results obtained in this work can be used to achieve the proper design of such gravitational motor.
