Abstract: The cross-spring pivot consists of two leaf springs which are located in two different planes and arranged crosswise. The cross-spring pivot offers many advantages including large rotation range and high precision. Each of the leaf spring in a cross-spring pivot can be considered as a thin beam subject to combined end force and end moment, so its deflected configuration is quite complex and is difficult to be modeled. The cross-spring pivot is precisely modeled by using the comprehensive elliptic integral solution for the large deflection problem derived in our previous work and the stress check method is given. The model is used to analyze two different cross-spring pivots. The simulation results show that the nonlinearity of the stiffness of this kind of pivot becomes remarkable when the deflected angle is larger than 30°. The cases that the deflected configurations of the leaf springs carry inflection points are presented. The strength of each cross-spring pivot at large deflected angle is checked. The finite element software is also used to analyze the nonlinear deflections of cross-spring pivot, which results are well agreed with the model of the comprehensive solution.

Key words: comprehensive elliptic integral solution;cross-spring pivot;nonlinearity;inflection point