一种滑动轴承非线性油膜力变分近似计算方法

An Approximate Variational Approach of Non-linear Oil Film Force of Hydrodynamic Bearing

基于变分原理,在π油膜假设条件下,利用无限长轴承的压力解,给出了滑动轴承非线性油膜力的近似表达式,同时在实际轴承参数条件下,对比分析了计算结果及数值解,发现该计算结果具有较高精度.

The shortbearing and longbearing models have been widely used to calculate the nonlinear oil film force in nonlinear rotor dynamics. However, these analytical approximations lead to significant error owing to the gaps between their hypotheses and the practical bearing parameters. Thus it is imperative to establish more accurate analytical model for calculating the nonlinear oil film force in practical nonlinear rotor dynamical design. Accordingly, the approximate formulae for calculating the nonlinear oil film force are derived using variational principle, with the circumferential pressure distribution expressed as the solution of the longbearing model. The results from the established formulae are compared with that from the numerical solution. The comparison shows that the analytical models for calculating the nonlinear film force gives increased accuracy than the conventional shortbearing and longbearing models, though a relatively larger error of Fx is observed at an extended axial velocity perturbation.