航空发动机大长径比传动杆轴承润滑结构设计方法研究

Research on the design method of lubrication structure of bearing of Drive Shaft with Large Aspect Ratio of Aero Engine

中文关键词: 传动杆  花键  轴承  润滑  航空发动机

英文关键词: Gear lubrication  Gear test rig  Flowmaster  FDGS  GTF

中文摘要:

      民用大涵道比涡扇发动机中常采用一种长径比很大（一般大于10）的空心传动轴，其作用是连接中央传动齿轮箱与附件传动齿轮箱，传递发动机附件及飞机附件正常工作所需扭矩，通常称为径向传动杆。该传动杆在两端集成有花键结构，分别与上下游齿轮轴配合，中间采用一轴承支撑。传动杆工作转速很高（一般大于20000r/min），为保证传动杆工作持久可靠，其花键副、轴承必须得到良好的润滑。本文根据发动机空间限制、传动杆自身结构特点、传递功率、工作转速等要求，进行了传动杆供油结构设计，并通过实际供油试验对设计进行了验证，结果表明供油结构能够实现预期功能，并分析了设计与试验结果的差异，为进一步优化设计提供参考。

英文摘要:

      The drive shaft with large aspect ratio(normally over 10:1)is usually used in the commercial aero engine with huge bypass ratio.The function of the shaft is connecting the inlet gearbox and According to the requirement of accurate oil feeding to each oil nozzle of the test gearbox for a fan drive gear system (FDGS) testing, a multi-variable pressure oil separation unit was installed in the oil supply flow of the gear test system, which is closed power and provide by hydraulic load. The inner cavity of oil separation unit contains a number of branches with throttling components. The pressure drop of each throttling component is controllable by adjusting the diameter and length of throttle holes. In this way, multi-line oil with different pressure is supplied to the oil nozzles, which ensure that the oil flow rate and velocity at the oil nozzles can precisely comply with test requirements. In order to study the effects of the throttle holes diameter and length on oil flow rate and velocity at the oil nozzles, a one-dimensional, steady-state simulation of oil supply line in the gear test system was conducted using Flowmaster. The results show that the throttle hole diameter has much significant impact on pressure drop rather than that of throttle hole length. Especially when the throttle hole diameter is adjusted between 1mm to 3mm, the throttling component exhibit an obvious regulating effect on the oil feeding pressure of the gear test system.