A generalized semi-analytical load distribution model for clearance-fit, major-fit, minor-fit, and mismatched splines

Abstract

A generalized semi-analytical load distribution model for all common types of involute spline joints is proposed. It is formulated to model clearance-fit (side-fit) involute splines with contacts happening only at the drive flanks of the spline teeth, major or minor-diameter fit splines where additional contact occurs along the top land and the root land of the external spline teeth, respectively, as well as mismatched splines where an intentional lead mismatch is introduced to initiate contact along both drive and back (coast) flanks. Using this model, load distribution and tooth-to-tooth load sharing of example major and minor diameter-fit spline joints under typical multi-directional spur and helical gear loading conditions are characterized and compared to those of the corresponding side-fit spline joint. Further, self-centralizing performance of major and minor-fit splines versus side-fit splines is quantified including its sensitivity to the radial clearance magnitude. Finally, load distribution of an example side-fit spline having various intentional mismatch magnitudes at different torque level is investigated to show that a given mismatch value is optimal at a certain design torque.