整体式平箔气体动压止推轴承静特性分析  

Static Performance Analysis of Integral Top Foil Gas Dynamic Thrust Bearings

作　　者：柳煜明 马希直[1] 郑文杰 成君康 赵凯 LIU Yuming;MA Xizhi;ZHENG Wenjie;CHENG Junkang;ZHAO Kai(College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing Jiangsu 210016,China)

机构地区：[1]南京航空航天大学机电学院,江苏南京210016

出　　处：《润滑与密封》2024年第6期50-56,共7页Lubrication Engineering

摘　　要：整体式平箔气体动压止推轴承具备制造工艺简单,承载能力强等优点,其由多个带有独立波箔的轴承扇区组成,但具有一个完整的环形平箔片。为了探究该新型轴承工作机制和静特性,提出相应的静特性分析模型并利用循环边界耦合条件,设置气流入口与出口处压力相等,利用数值仿真分析整体式平箔止推轴承的转速、最小气膜厚度和楔形高度对其静特性的影响,并与相同工作条件下的分离式平箔轴承进行比较。研究结果表明:整体式平箔所设计的轴承在负载情况下平箔片会由楔形-台阶转变为楔形-平端的几何形状,单瓦扇区后缘因变形向上弯曲产生二次收敛间隙,因此形成2个气膜压力峰值,且由于轴承面积较分离式平箔所设计的轴承更大,因此承载能力会更高;由于平箔台阶处存在负压区,因此整体式平箔最优楔形高度区间延后于分离式平箔出现,当楔形高度在50μm左右时,能够达到较高承载能力并且摩擦力矩较小;当增加最小气膜厚度时,其承载能力与摩擦力矩均减小。The integral top foil gas dynamic pressure thrust bearing has the advantages of simple manufacturing process and high load capacity,which consists of several bearing sectors with independent bump foil,but has a complete annular top foil sheet.In order to investigate the working mechanism and static performance of this new bearing,the corresponding static performance analysis model was proposed and the cyclic boundary coupling condition was used to set the pressure at the inlet and outlet of the gas stream to be equal.The effects of the speed,minimum film thickness and wedge height on the static performance of the integral top foil thrust bearing were analyzed through numerical simulations,and the analysis results were compared with those of the separated top foil bearing under the same operating conditions.The results show that the top foil sheet of the integral top foil bearing will change from wedge-step to wedge-land geometry under load,and the trailing edge of the single tile sector will be bent upward due to deformation to produce a secondary wedging effect,thus forming two air film pressure peaks.And the integral top foil bearing also has a larger bearing area than the separated type bearing,so its load capacity will be higher.Due to the negative pressure zone at the top foil step,the optimal wedge height interval of the inegral top foil is delayed compared with the separated top foil,and a higher load capacity and a smaller friction torque can be achieved when the wedge height is around 50 μm.When the minimum film thickness is increased,both the load capacity and the frictional torque are reduced.

关 键 词：整体式平箔 气体箔片推力轴承 二次楔形 静态特性 流固耦合 

分 类 号：TH133.35[机械工程—机械制造及自动化]