Theoretical And Experimental Study On Lubrication Characteristics Of Texturized Bearings Considering Roughness

Sliding bearing with its high load capacity,high rigidity,high rotary accuracy and low friction factor,widely used in high-speed heavy load high-precision rotating machinery.In the sliding bearing processing production shingle surface often produces irregular surface morphology,mainly in the form of roughness and surface micro-pits,etc.,reasonable control of its shape,size parameters is a key factor in reducing the impact on the tribological properties of sliding bearings.In the in-depth study of surface morphology,it is found that the preparation of a series of regular weaving on the surface of the bearing domain of the friction substrate can achieve the friction reduction effect of the sliding bearing.In this paper,based on the theory of hydrodynamic lubrication,a theoretical model of hydrodynamic bearing with square micro-weave is established based on the random longitudinal roughness model,and the Reynolds equation is solved by the finite difference method.The calculation formula of static and dynamic characteristics is established,and the weaving boundary treatment is performed for the abrupt change of film thickness in the weaving region.The influence of lubrication characteristics is analyzed for bearings with smooth,single roughness,single micro-weave and coupled rough contours of weave-configuration bearings,and the static and dynamic characteristics and stability change laws of dynamic pressure bearings under the conditions of four surface topography factors are calculated.The calculation results show that:(1)the load carrying capacity of a single weave-configuration bearing under small eccentricity conditions is improved compared with that of a smooth bearing;the frictional resistance and end-drainage flow rate increase slowly with the increase of eccentricity.(2)The load carrying capacity of the woven bearing with roughness increased with larger eccentricity,and the larger the eccentricity,the more significant the load carrying enhancement effect;the frictional resistance and end drainage flow also increased significantly with larger eccentricity,and also accompanied by temperature rise.(3)Micro weave depth and surface roughness parameters are the main factors affecting the bearing characteristics,taking into account the roughness of the weave structured dynamic pressure bearing with the change of roughness parameters can significantly improve its load carrying capacity;with the increase of weave depth its equivalent oil film thickness increases,and the friction is also improved.In the experimental study,the mechanism of surface profile formation by different processing methods is discussed,and two types of surface profile specimens are prepared and characterized using two processing methods.The friction subs obtained by ultrasonic vibration-assisted processing both homogenized the roughness peaks and formed regular textured surface micro-weave,and the multi-scale surface weave of the shafts was prepared by laser etching.The experimental study of the friction characteristics of the dynamic pressure sliding bearing was carried out under different roughness and micro-weave parameters;the results were analyzed and compared with the theoretical calculation.Useful process parameters and experimental results were obtained,which provide a reference for further investigation of the influence of sliding bearing surface morphology on tribological properties.