局部多孔质气体静压轴向轴承静态特性的数值求解
Numerical Solution of Static Characteristics for Partial Porous Aerostatic Thrust Bearing
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摘要: 运用数值方法分析局部多孔质节流气体静压轴向轴承的静态性能,分别建立局部多孔质圆柱塞内的压力分布方程和气体薄膜内的压力分布方程,利用坐标变换将局部多孔质圆柱塞的圆柱坐标与气体薄膜的圆柱坐标转换到同一笛卡儿坐标系,为有限元离散奠定基础.经过有限元推导,求得局部多孔质气体静压轴向轴承的承载能力与静态刚度,并对局部多孔质节流进行试验以验证理论模型的正确性.另外,对局部多孔质节流气体静压轴向轴承和小孔节流气体静压轴向轴承进行对比试验.结果表明:局部多孔质节流和小孔节流静压轴承的承载能力随着气膜厚度的减小而增加;静态刚度随着气膜厚度的增加先增加后减小;局部多孔质节流比小孔节流具有较高的承载能力和静态刚度.Abstract: Static characteristics of an externally pressurized gas thrust bearing with partial porous restrictors were investigated by means of the numerical method. The pressure distribution equations of the partial porous cylinder and gas film were separately established. For establishing the finite element model, the coordinates of partial porous cylinder and gas film were transformed to the uniform Cartesian coordinate. The load capacity and static stiffness of the bearing with partial porous restrictors were obtained via the finite element method. The theoretical results were in good agreement with the experimental data, which reached the accurate of the theoretical model. Theoretical and experimental results showed that the load capacities of the bearing with partial porous restrictors and orifice restrictors increased as the gas film decreasing and their static stiffness firstly increased and diminished as the gas film increasing. In addition, the bearing with partial porous restrictors and orifice restrictors were compared with the experimental results. Compared with the bearing with orifice restrictors, externally pressurized gas thrust bearing with partial porous restrictors exhibited higher load capacity and static stiffness.