基于非线性油膜力的滑动轴承动力特性系数识别方法

Identification Method of Rotordynamic Coefficients of Sliding Bearing Based on Nonlinear Oil Film Force

关键词:  滑动轴承  动力特性系数  油膜力  识别方法

Key words:  Sliding bearing  Rotordynamic coefficients  Oil film force  Identification method

摘要:

为了更简便地从滑动轴承非线性油膜力直接识别获得油膜动力特性系数，从频域角度建立了轴颈在轴承中的扰动与非线性油膜力之间的关系，采用等幅异频位移激励技术，一次性识别出油膜8个刚度和阻尼特性系数，通过圆瓦滑动轴承实例验证了该方法的准确性，分析了扰动幅值和频率对识别精度的影响。研究结果表明，扰动频率对识别精度没有明显影响，而扰动幅值对识别精度有较大影响，当扰动幅值大于0.016倍半径间隙时，识别精度超过5%。当扰动幅值小于0.005倍半径间隙时，识别精度在0.5%以内，0.001倍半径间隙时，所给出的油膜动力特性系数识别方法的识别精度可达到0.045%。

Abstract:

In order to recognise the rotordynamic coefficient directly from the nonlinear oil film forces of sliding bearing more efficiently，the relationships between the journal disturbance and nonlinear oil film forces are established in frequency domain，and eight stiffness and damping coefficients are identified respectively by using the technique of only one journal disturbance with the same perturbation amplitude but different frequency. The accuracy of the identification method is demonstrated by a plain journal bearing case，while the influences of accuracy with disturbance amplitude and frequency are analyzed. The results show that disturbance amplitude has great influence on the accuracy but the disturbance frequency does not. When the disturbance amplitude is larger than 0.016 times or less than 0.005 times the radius clearance，the recognition accuracy is more than 5% or less than 0.5%，respectively. Specially the accuracy of recognition can be up to 0.045% when the disturbance amplitude is 0.001 times the radial clearance.