Theoretical and experimental investigation of performance characteristics and design aspects of cross-spring pivots

Cross-spring pivots have been widely employed over the last decades in a broad variety of precision engineering applications due to the high motion repeatability achieved thanks to the absence of stick slip and clearance. In this paper, the non-linear effect of the anticlastic curvature of the leaf-springs is considered for the accurate analytical modeling of the elasto-kinematic behavior of cross-spring pivots. Finite element analyses (FEA), based on a non-linear thin-shell model, are carried out in order to compare them with the analytical results for the main performance parameters of this type of device, i.e. center-shift, rotational stiffness and stress in the leaf-springs. Furthermore, an experimental setup is built to assess the applicability limits of both models. Finally, remarkable performance aspects of cross-spring pivots are discussed aiming for design improvements

Six Sigma critical success factors in Brazilian industry

Purpose – The purpose of this paper is to identify critical success factors (CSFs) that are regarded as the most important in Six Sigma programs in Brazil and to compare these rankings with those in international literature. Design/methodology/approach – A sample of industrial companies was selected to complete a survey. In total, 104 questionnaires were obtained. The results were compared with a literature review consisting of 26 papers from 13 countries. In total, 70 CSFs were found in the papers, but 19 CSFs were analyzed and reduced to ten. A multivariate factor analysis further reduced this number to two underlying constructs. Findings – The authors identified a CSFs common denominator/ranking based on the sample of international articles. The authors found that there are four CSFs that are more prevalent in Brazil and in the international papers studied and that there are no differences between the importance of CSFs in terms of hierarchical levels. Three gaps, five levers and two CSFs constructs were identified. Social implications – This study may initiate cooperation between the studied companies and academia, thus possibly increasing these organization’ knowledge regarding Six Sigma. Originality/value – The originality of this study is that the survey was conducted with companies in Brazil, a country where little information exists on Six Sigma programs. The authors also contributed a literature review on CSFs, a comparison based on most of the consulted papers and the use of a robust methodological strategy that was made possible by the sample size. </jats:sec