滑动轴承二维流场的滑移现象研究

Study on Two-dimensional Wall Slip of Sleeve Bearing

目前对于二维流场及复杂流场的界面滑移分析很少,根据螺旋油楔滑动轴承能使润滑剂产生周向和轴向二维流动的独特的结构特点,考虑周向和轴向两方向的滑移建立基于极限切应力的数学模型,并通过试验和理论对比验证模型的正确性。试验方面运用'目标速度跟踪法'证实了周向和轴向都存在滑移,获知随着供油压力的提高滑移速度有所提高,并且提出轴瓦和轴表面的极限切应力;理论方面运用有限差分法和试验测得的轴瓦和轴表面极限切应力,求解四种状态的广义雷诺方程,发现滑移发生在极限切应力大、间隙小和油膜的封油面区域;考虑界面滑移时,螺旋油楔滑动轴承的承载力和摩擦阻力有所降低;偏心率、螺旋角和转速的变化,影响着承载力和摩擦阻力降低的幅度。

The wall slip analysis of two-dimensional and complex flow is seldom.According to the different structure of the spiral oil wedge journal bearing that can produce the two-dimensional circumferential and axial flow,the modified Reynolds equation is established based on the critical shear stress model,in which circumferential and axial wall slip of the sleeve and axial surface is considered,and the model is proved by theory and experiment.In experiment,circumferential and axial wall slip is proved by the method of target speed tracking method,slip velocity increases with the increase of input pressure,and the critical shear stresses of sleeve and axis surface are obtained.In theory,by means of the finite differential methods and the critical shear stresses of sleeve and axis surface that are obtained in experiment,the four modified Reynolds equations are solved.It is obtained that the wall slip occurs first in the large shear stresses,the small clearance and the envelop zone by the theory model.Wall slip can decrease the carrying capacity and friction.Eccentricity,spiral angle and rotating speed have effects on the reduction magnitude of the capacity and friction.