Analysis of Under-Race Lubrication Characteristics for Aero-Engine Accessory Gearbox Bearings
WANG Guanneng
NIU Rongjun
ZHANG Yuanyuan
WANG Dandan
GAO Xiaoguo
Abstract：Aero-engine accessory gearbox bearings operate under high speed,high temperature,and complex load conditions,where their lubrication state directly affects engine reliability and service life.To address the shortcomings of conventional side-jet lubrication in oil distribution uniformity and cooling efficiency,this study investigates the under-race lubrication scheme for accessory gearbox bearings.Based on a developed local frictional heat model and a fluid-thermal-structural coupled two-phase oil-gas flow model,computational fluid dynamics methods were employed to systematically analyze the effects of oil hole diameter,number of holes,oil supply rate,and rotational speed on the internal lubrication characteristics of the bearings.Results show that increasing the oil hole diameter from 0.4 mm to 0.8 mm slightly reduces the oil volume fraction in the bearing cavity;increasing the number of holes from 4 to 8 significantly improves circumferential uniformity;increasing the oil supply from 0.01 L/min to 0.25 L/min steadily raises the total oil content in the cavity and enhances lubrication coverage on the outer ring;as the speed increases from 2 000 r/min to 10 000 r/min,the oil distribution gradually extends from the inner ring to the entire bearing cavity,while the effect of gravity is significantly reduced.The study indicates that under-race lubrication significantly improves lubrication coverage and uniformity,providing a theoretical basis and reference for efficient bearing lubrication design and oil supply system optimization in aero-engines.
Keywords：under-race oil supplybearing lubricationtwo-phase flowflow field simulation
Publication Date：2026-02-25
Online Publishing Date：2026-03-19(First online date of this platform, not the publication date of the document)
Pages：11( 42-52 )