Injection parameter design to improve the high-speed gear heat dissipation: CFD simulation and regression orthogonal experiment

A heat dissipation model of high-speed helical gears based on Computational Fluid Dynamics (CFD) is proposed under injection lubrication. Gear heat dissipation is investigated by static and dynamic heat flow coupling. The oil injection lubrication test is designed to measure tooth temperature by an infrared thermal imager. The results show that owing to the gear centrifugal force, the oil splash, and the blocking effect of the high-speed airflow, the average temperature first decreases and then increases, and the temperature difference increases first and then decreases with the increase in injection angle, distance, and velocity. The average temperature and temperature difference are remarkably affected by the injection velocity and distance, respectively. The optimal injection angle, distance, and velocity predicted by the regression orthogonal method are 9.212°, 54.514 mm and 35.561 m/s, respectively. Infrared thermometry experiments show that the optimal injection parameters enhance the gear heat emission by 6.93%. These findings provide support for the heat dissipation study and injection system design for aerospace gears.