Investigation of load carrying capacity of asymmetric high contact ratio spur gear based on load sharing using direct gear design approach

•Asymmetric high contact ratio gear developed through direct design•Rack parameters are derived from area of existence.•Importance of load sharing for high quality non-standard gears•Increase in gear ratio and number of teeth enhances the load capacity.

The Direct Gear Design® approach is one of the many gear designing methods available to improve load carrying capacity of the gear pairs. For customized gear pairs, the direct gear design approach is more advantageous over conventional design. In this paper, a parametric study is carried out for asymmetric high contact ratio spur gears based on load sharing method to determine the improvement in load carrying capacity. A finite element model for multi-pair contact is adopted to determine the non-dimensional fillet and contact stresses which quantify the load carrying capacity of the gear pairs. The results of direct designed symmetric and asymmetric high contact ratio spur gears are compared with the conventional symmetric high contact ratio spur gears. Also, the influence of gear parameters such as addendum pressure angle, gear ratio, teeth number and backup ratio of non-dimensional stresses is analyzed in detail. The results show significant improvement in gear pair performance for all parameters analyzed.