Theoretical and Experimental Study of Friction Characteristics of Textured Journal Bearing

Abstract

The proposed lubrication theory of textured journal bearing is a major innovation in the study of the tribological properties of surface morphology. When it comes to the study of surface topography, it is essential to consider the effect of surface roughness when analyzing the characteristics of journal bearing. In this paper, a Reynolds equation containing longitudinal roughness is established for journal bearing and solved by the finite difference principle to obtain the bearing load and friction characteristics. Subsequently, a combination of laser etching and ultrasonic vibration milling processes was used to prepare 5 µm, 20 µm, and 40 µm bearing friction subsets with square micro-texture surfaces. The analysis of the results shows that the surface roughness distributed in the non-texture region can substantially increase the oil film pressure. When the roughness profile and the surface weave work together, the presence of a surface texture with an optimum depth of 5 µm within a roughness range of less than 1.6 µm can improve the load-bearing characteristics by a maximum of 43%. In the study of the preparation of textured bearing friction substrate, it was found that laser etching can ablate the surface of the friction substrate to a depth greater than 20 µm with the ideal effect, while the surface texturing to a depth of 5 µm is more suitable using an ultrasonic vibration processing process. In the simplified journal bearing operating condition, the frictional wear test shows that if the effect of roughness is considered, the frictional force of the depth of 20 µm and 40 µm is significantly reduced and changes less with increasing load, while the frictional force of the textured frictional pair with a depth of 5 µm is improved but significantly affected by the load carrying capacity. Therefore, when the difference between the roughness profile and the depth of the texture is of a small order of magnitude, it indicates that the effect caused by the roughness factor is not negligible.

Change in Time of the Value of Dry and Lubricated Friction Coefficients for Surfaces Generated by Different Processing Methods

“…The influence of the shape of the surface involved in the study of the friction process on the values of some friction characteristics [3,11,28,29]; -Identifying the theoretical non-linear correlation of the data concerning specific aspects of the friction of textured surfaces [11,17,25,29]; -Laser surface texturing and the possibilities of affecting the tribological characteristics of surfaces through such a process [2, 6,8,13,15,16,24,[29][30][31][32]; -…”

“…The study of the friction process specific to the operation of some mechanical parts [1,4,14,22,35]; -Experimental research on the influence of different factors on some tribological characteristics [4,6,10,29,[36][37][38]; -Highlighting equipment solutions for the study of friction processes [6,7,[9][10][11][12]15,17,20,24,28,[30][31][32]34,38]; -Carrying out extensive analyses of the results obtained in the field of specific friction of textured surfaces [2,11]; -…”

“…The study of the wettability properties influences the values of some characteristics of the friction processes [12,24,29,32].…”