Effects of Scratches on Lubrication Performance of Elliptical Bearing and Stability of Rotor System

doi:10.3901/JME.2021.11.256

Abstract

Abstract: Scratches on the surface of the bearing caused by the particles is a common phenomenon in the operation of sliding bearings. To study the effect of scratches on the lubrication characteristics of radial sliding bearings, a thermo-hydrodynamic lubrication model is established based on turbulent flow and mass conservation boundaries. The static and dynamic performance of the bearing is solved by the finite element method. From the theoretical and experimental perspectives, the effect of scratches on bearing performance (oil film thickness, pressure, temperature, power consumption, flow rate, stiffness, damping, etc.) under different rotation speeds and loads is compared. The effect of scratches on the stability of the rigid rotor system is discussed. The results show that: in terms of static characteristics, when the scratch depth and the gap reach the same level or higher, the minimum oil film thickness of the bearing is significantly reduced, the maximum temperature is increased, the maximum pressure is significantly increased, and additional bending moment is induced. In terms of dynamic characteristics, scratches have a significant impact on the stiffness, damping, unbalanced response and stability of the rotor system. Generally, scratches on the surface of bearing will reduce the critical speed of the rotor system and increase the amplitude. Under low-speed conditions, scratches will reduce the stability of the rotor system, under high-speed conditions, scratches will increase stability. This study has certain engineering reference value for evaluating the effect of scratches on bearing lubrication performance.

Key words: scratches, elliptical bearing, lubrication characteristics, stiffness, damping, stability

CLC Number:

TH133

WANG Xiaohong, PEI Shiyuan, CHANG Shan. Effects of Scratches on Lubrication Performance of Elliptical Bearing and Stability of Rotor System[J]. Journal of Mechanical Engineering, 2021, 57(11): 256-264.

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