圆锥型螺旋槽气体动压轴承气膜压力分析

Analysis on the Gas Pressure Distribution of Conical Spiral Groove Aerodynamic Bearings

气体动压润滑轴承具有摩擦力小、速度高、磨损少等特性,对用可压缩气体润滑的圆锥型螺旋槽动压轴承进行了研究.由于圆锥轴承的特殊结构以及螺旋角的存在,对轴承的求解域进行了保角变换和斜坐标变换.采用局部积分有限差分在不连续求解域的纵向和横向推导出了控制方程在斜坐标系下的差分形式.并对轴承的压力分布进行了数值计算.结果表明:螺旋槽能很好实现气体轴承动压效应,压力在圆周方向上呈锯齿形分布,轴承的转速和槽深比不同对轴承的气膜压力的影响不同.

The conical spiral groove aerodynamic bearings lubricated with compressible gas have been investigated theoretically for their merit of infinitesimal friction, high rotary speed , high rotary precision, less wear abrasion, and so on. Because of the special structure of conical bearings and existence of spiral groove, conformal mapping and oblique coordinate transformation have been processed for calculated regions of the governing equations. By employing the regional integral finite difference method, the finite difference formulas of the governing equations in longitudinal and transverse orientation have been deduced in oblique coordinate. The paper focusses on the numerical analysis for pressure distribution of the bearing, and on the discussion to the computed result. The results show that the spiral grooves can realize hydrodynamic effect of gas bearings, and pressure distribution assumes sawtooth shape in peripheral orientation. The rotate speed and trough deep rate has different effects on gas interspace pressure of bearings.