深腔圆锥动静压混合轴承润滑特性

Lubrication characteristics of deep cavity hybrid conical bearing

摘要:

为了更加准确探求深腔圆锥动静压轴承润滑特性,考虑润滑油膜紊流、热效应及轴向速度等因素,推导极坐标系下的广义雷诺方程、能量控制方程及其相关表达式,采用有限差分法对方程进行离散,利用帕坦卡正系数法则对离散化方程系数及常数项进行处理,数值分析油膜的三维压力场和温度场,试验研究静压浮起和动压润滑特性．结果表明:帕坦卡正系数法则可以有效地解决诸如油腔边缘存在“逆流”等因素而导致温度场不易收敛问题,在高速大偏心率情况下,油膜温升较高,应考虑温度对轴承性能的影响．流量与供油压力成正比关系,而与转速基本无关．随着转速增加动压效应增强,轻载时轴承在小偏心率下工作．深腔圆锥动静压轴承具有良好的静压浮起和动压润滑特性,理论计算值与试验结果一致,证明理论的正确性,为下一步转子动力学的理论分析打下基础．

Abstract:

To deeply study lubrication characteristics of deep cavity hybrid conical bearing, oil film generalized Reynolds’ equation in polar coordinates, energy control equation and the related expressions were deduced with consideration of turbulent fluid, heat effect and axial velocity of fluid film. Finite numerical difference method was used to discretize equations and Patankar’s positive coefficient law was adopted to process coefficients and constant terms of the discrete equation. Results showed that the Patankar’s positive coefficient law efficiently solved reverse-flow at Oil cavity edge. Under circumstances of big eccentricity and high speed, temperature of lubricating oil film gets high and the influence of bearing performance should be taken into account. The flow is proportional to the input pressure and independent of speed. With the increasing of speed, dynamic effects are improved and the bearing eccentricity is small with light loads. Deep cavity hybrid conical bearing shows excellent performances of static pressure up and dynamic lubrication, and the theoretical analysis results are agree well with the experimental tests.