Chernets M.V., Chernets Yu.M. Influence of wheels width cylindrical gear on contact pressures and durability.

Abstract

With the use of author’s calculation method of durability of tooth gears with height engagement correction, it has been conducted the investigation of influence of wheels width and teeth slope angle on maximum contact pressures and dura-bility of cylindrical gears at changeable conditions of teeth contact in the result of their wear. It has been established that close in values the highest maximum contact pressures arise at teeth entrance into engagement and in the zone of its parity change both in spur and helical gears. In spur gears double – single – double tooth engagement would arise for the whole range of wheels width change. Instead, in helical gears with an increase of wheels width engagement parity changes from double – single – double into triple – double – triple. Respectively, these factors influence the decrease of initial maximum contact pressures level up to 1.5 times and the increase of durability of uncorrected helical gears up to 3.8 times in compari-son with spur gears. Engagement correction leads to decrease of maximum contact pressures, in the result of which gears du-rability increases. It has been established that optimum shift coefficients exist, at which gear durability would be the highest as compared with uncorrected engagement. The obtained results are given graphically, that better shows the regularities of wheels width, teeth slope angle and engagement conditions influence on the investigated tribotechnical characteristics. Key words: involute cylindrical gear, tooth height correction, teeth width, teeth slope angle, maximum contact pressures, tooth wear, gear durability.