Optimum Power Contribution Ratio of Two Pinion Gears Engaged with Rack Rail for Monorail Driven in Forest Industry

摘要

The purpose of this study is to find the optimum power contribution ratio defined as the ratio of traction force applied onto rack rail by front pinion gear and rear pinion gear of monorail used in this study. At first, relation between loading weight and applied stress was investigated when loading weight Mb on the bogie was changed. Power contribution ratio was estimated using this relationship. The effect of the condition of power contribution ratio on the normal stress applied onto the rack tooth was simulated using obtained relations. The optimum power contribution ratio of front pinion gear was defined as an effective designing parameter to reduce the stress applied onto the rack tooth. A reduction ratio determined with the ratio of maximum compression stress on the tooth considering power contribution ratio to that of conventional case was estimated when the optimum power contribution ratio was considered. It was found that most of traction force was sheared by the front pinion gear not depending on magnitude of traction force, because the revolutions of the front and rear pinion gears was directly constraint due to the link system of the connection in the gear box of current monorail. The optimum power contribution ratio was α=0.53 when the representative location of the contacting forces on front pinion gear was hl=5.6mm measured from the root of tooth, and that on rear pinion gear was h2=7.0mm, respectively. The maximum reduction with 47% in observed compression stress was obtained by determining optimum power contribution ratio under the condition at 5.54kN of total traction force.