Problem of selection of reference plane with deep and wide valleys analysis

Abstract

Areal form removal of cylindrical surfaces containing deep and wide valleys was often analysed; the influence of selection of filtering techniques was taken into consideration in many original researches. However, the errors of reference plane selection on surface topography parameters of cylindrical elements containing deep and wide dimples (oil pockets, scratches) were not fully recognized. In this paper, the improper selection of reference plane in surface topography analysis of cylindrical elements with deep or wide oil pockets were taken into consideration. The errors of surface topography parameters (from ISO 25178 standard) caused by improper areal form removal were presented; some parameters were specified according to its the biggest distortions. It was proposed to select the reference plane with particular attention to the specified parameters. It was assumed that proposal of bandwidth (cut-off) values in digital filtering depends on both size and distance between dimples.