Dynamic Structural and Thermal Characteristics Analysis of Oil-Lubricated Multi-speed Transmission Gearbox: Variation of Load, Rotational Speed and Convection Heat Transfer

Abstract

The main objective of this research work is to investigate the effects of load, rotational speed and lubrication on gear surface of multi-speed gearbox. Transient structural analysis was performed to evaluate the strength of multi-speed transmission gearbox assembly. Gear oil SAE 85W140 lubricant was used for cooling of gearbox and performance enhancement of medium-duty trucks. To investigate the thermal characteristics of multi-speed transmission gearbox, steady-state thermal analysis was performed with combined varying condition of load and rotational speed of shafts (pinion and gear) with gear oil lubricant. At different operational conditions, the temperature of gearbox surface was measured. An average heat transfer coefficient (h) of the gear surface and tooth flank (100–500 W/m2 K) was varied for steady-state analysis. Solid model of multi-speed transmission gearbox was designed using Solid Edge and Pro-E. Finite element analysis (FEA)-based numerical simulations of multi-speed transmission gearbox were established to find the temperature variations on gear surface. FEA simulation results were validated with the experimental results available in the literature.