Systematic two-zone modelling for performance prediction of centrifugal compressors

Abstract

The ubiquitous microdrills with planar point geometry used by industry suffer from a number of undesirable characteristics and limitations that influence their drilling performance with respect to hole quality and tool life. In this paper, a new family of drill points, the 'curved helical drill points', and the related grinding methods for their manufacture are introduced to alleviate the undesired characteristics and limitations of planar drills. The mathematical foundation and an analytical and graphical comparative drill point geometry analysis between curved helical drill points, linear helical drill points and planar drill points are presented.