Investigation of the effect of speed ratio on workpiece surface topography and grinding power in cylindrical plunge grinding using grooved and non-grooved grinding wheels

Abstract

Speed ratio is the ratio of the grinding wheel angular speed to the workpiece angular speed. In this paper, it is shown that this parameter has a significant impact on workpiece surface roughness, workpiece texture, and power consumption. Integer speed ratios were investigated between 2 and 7 and selected non-integer speed ratios were studied between 4 and 5. When compared to non-integer speed ratios, integer speed ratios yielded poor surface roughness for non-grooved wheels and visible surface textures for grooved wheels. Furthermore, the non-integer speed ratios exhibited a complex pattern of roughness spikes. The concept of grain synchronization was developed to explain these phenomena. Grain synchronization is the number of grinding wheel revolutions required before grain trajectories overlap—which will happen provided the speed ratio is a rational number. It was shown how grain synchronization can be calculated using the speed ratio. Non-integer speed ratios that resulted in rapid grain synchronization were shown to result in poor surface finish and low grinding power while speed ratio that resulted in longer grain synchronization resulted in better surface finish and higher grinding power suggesting that some speed ratios should be avoided. For a given speed ratio, grooved wheels were shown to produce lower grinding forces and higher surface roughness.