Experimental study on polishing process of cylindrical roller bearings

Abstract

The surface quality and accuracy of the geometry of the cylindrical rollers are important factors for bearing life. This paper presents effects of machining parameters on the surface roughness, topography and roundness of cylindrical rollers through the lapping and polishing experiments. And then the surface roughness of the cylindrical rollers is optimized. The results found that the surface roughness of rollers is significantly changed in lapping process with different abrasive particle sizes, while the surface roughness has slightly reduced in polishing process. It also indicated that the smoother surfaces with better roughness can be obtained after lapping and polishing process. In addition, the surface roughness of cylindrical rollers is rapidly reduced from Ra of 0.5 µm to Ra of 0.063 µm after the 3-h lapping process and Ra of 0.013 µm after the 1-h polishing process. The surface topography of rollers can be achieved by the smoother surface when loads are from 25 to 35 N in lapping process, and the loads are from 35 to 40 N in polishing process. Finally, the Taguchi method is applied to optimize the surface roughness in polishing process. The result found that the optimal surface roughness achieves 0.015 µm with respect to the time of 35 min and type of 4000# Al2O3.

Numerical simulation on residual stresses of stainless steel SS-304 thin welded pipe

“…Figure 6 shows the curve of the axial residual stress compared with the experimental data of residual stresses measured with the XRD. 37 The maximum temperature is at the weld bead area as anticipated. In front of the heat source, there is a steep temperature gradient, which shows the unimportance of flow of heat in front of the welding arc.…”

“…Figure 6 shows the curve of the axial residual stress compared with the experimental data of residual stresses measured with the XRD. 37 Results and discussion Figure 7, it is clear that the temperature of the different nodes varies with the movement of the arc. The thermal profile and the structure of the weld bead are symmetrical with respect to welding axis.…”

“…Figure 6 shows the curve of the axial residual stress compared with the experimental data of residual stresses measured with the XRD. 37…”

Building a model of the process of shaping tapered calibrating areas of wheels at the two-sided grinding of round ends

“…Work [11] considers the impact of the quality of the machined surface of bearing rollers on the durability of their work. Study [12] reports methods for improving the quality of the surface layer of bearing rollers and shows that its condition significantly increases the life of units. The authors of [13] performed mathematical modeling of the process of double-sided end grinding of various parts with a round profile, as well as components with different diameters of the ends.…”

“…where x kper , y kper are the current coordinates of the points of the line that is perpendicular to the calibration area and passes through the center of the part when it enters the calibration zone in the coordinate system of the wheel O w1 Х w1 Y w1 , mm. The coordinates of the beginning of the calibration area are defined as the point of intersection of the line, described by equality (5) and perpendicular to (12), that is,…”