Level-Difference Clearing Performance of Wheel Device Characterized by Eccentric Axle Position

Abstract

Theoretically, the minimum essential lateral force (hereafter called level-difference clearing force) required for a wheel to clear a level difference is decreased by moving the axle position forward and upward relative to the center of rotation of the wheel. In this work, we manufactured a wheel device characterized by such an eccentric axle position and studied its level-difference clearing performance. On the basis of the relationship between the lateral force and the elapsed time while clearing the level difference, the lateral force acting on a common wheel with the axle positioned at the center of rotation increased and reached a maximum just after the wheel encountered the level difference. However, for the proposed wheel device, the rate of increase in the lateral force decreased because the inner ring rotated backward while clearing the level difference. For a 40mm level difference, and movable loads of 12.7N, 7.84N, and 2.94N, compared with the common wheel, the proposed wheel device decreased the level-difference clearing force by approximately 24%, 24%, and 19%, respectively.