Analysis of TEHL Characteristics of Modified VH‐CATT Cylindrical Gear

Addressing the challenges of inadequate lubrication performance and limited thermal stability of variable hyperbolic circular‐arc‐tooth‐trace (VH‐CATT) cylindrical gear pairs under conditions of high speed and heavy load, this study presents a multi‐field coupled thermo‐elastohydrodynamic lubrication (TEHL) model. The model integrates cutter tilt‐induced lead modification, tooth contact analysis (TCA), finite element‐based contact mechanics and thermal‐elastohydrodynamic lubrication simulations. By selecting representative meshing instances, the research systematically examines the combined influence of entrainment angle ( θ ₑ) and lead modification angle ( γ ) on key parameters, including oil film thickness, pressure distribution and temperature elevation. The findings indicate that when θ ₑ deviates from 0° to either less than 0° or greater than 0°, the minimum oil film thickness decreases by approximately 5.03%. Concurrently, the maximum oil film pressure exhibits an increase of 22.33% and a decrease of 21.14%, respectively, while the temperature rise diminishes by 63.81% and 34.12%, respectively. Upon the introduction of lead modification with γ set at 5°, variations in θ ₑ below and above 0° result in reductions in minimum oil film thickness by 4.29% and 4.81%, respectively; decreases in maximum pressure by 8.89% and 3.97%, respectively; and changes in temperature rise characterised by a decrease of 83.75% and an increase of 72.94%, respectively. A comprehensive evaluation suggests that maintaining θ ₑ within the range of 0°–5°, alongside γ fixed at 5°, facilitates the synergistic optimisation of lubrication integrity, load‐bearing capacity and thermal management performance. This insight offers a theoretical framework and practical foundation for enhancing lubrication efficacy and structural design of VH‐CATT cylindrical gear pairs under complex thermal loading conditions.