球面螺旋槽动静压气体轴承动态特性分析

Analysis of Dynamic Characteristics of Spherical Spiral Groove Hybrid Gas Bearings

以半球螺旋槽动静压气体轴承为研究对象,建立球面动静压混合气体轴承的非线性动态润滑计算分析数学模型,采用偏导数法推导出扰动压力控制方程;在广义坐标系下,采用有限差分法对扰动压力控制方程离散化,推导出扰动压力的差分表达式;推导出半球螺旋槽动静压气体轴承刚度和阻尼系数与扰动压力之间的关系表达式;采用VC++6.0编制程序,数值计算出三维微气膜的瞬态扰动压力分布、非线性气膜力及动态刚度系数和动态阻尼系数。研究转速、偏心率及供气压力对气膜动态特性系数的影响规律,结果表明:随着转速、偏心率及供气压力的增大,气膜刚度和阻尼系数均有不同程度的变化。

The nonlinear dynamic lubrication analysis mathematical model of spherical hybrid gas bearings was established with the hemisphere spiral groove hybrid gas bearings as the researching object, and perturbation control equation was derived by means of the partial derivative method.The finite difference method was employed to discrete the perturba- tion control equation in generalized coordinate system, and the difference expression of perturbation pressure was derived. The relational expression involving the relationship between the beating dynamic characteristic coefficients and perturbation pressure was deduced. The transient perturbation pressure distribution of three-dimensional micro gas film, nonlinear gas film force, dynamic stiffness and dynamic damping coefficients of bearings were numerically computed using VC＋＋6. 0 programs.The influence law of supply pressure, speed and eccentricity ratio on the bearing dynamic stiffness and damping coefficients was researched.The results show that the influence of beating＇ s speed, eccentricity and supply pressure on the dynamic characteristics of gas film is significant.