Analysis of stress and fatigue life of ball screw with considering the dimension errors of balls

Ball screw is a kind of mechanism, it is widely used in machinery and may be loaded with axial and radial load in practice. In the past, people calculated the contact load of ball screw which only bear axial load and didn't take the influences of dimension errors of balls into consideration. The authors take ball screw with outer cycling device as the research object, establish a calculation model to calculate the contact stress and fatigue life of ball screw by mechanics analysis. With a concrete example, the authors study the contact stress and fatigue life of three situations, the first one is that every ball has no dimension error, the second one is that only one ball has dimension error, and the third one is all balls have random dimension errors. The results have been analyzed and explained. At the same time, the authors analyze the influences of axial load, radial load and size accuracy of balls on the fatigue life of ball screw. (C) 2017 Elsevier Ltd. All rights reserved.