Improving the Dynamic Properties of the Crank-Slider Mechanism with Joint Clearance Using Optimal Flexure Joint

Traditional joints always have some clearance which increases accelerations and forces. Flexural joints are a new type of joints that the clearance is eliminated and can be built seamlessly. The presence of intrinsic stiffness in the flexural joints increases the stiffness of the joints, and it can reduce the difficulties caused by clearance in other joints. The purpose of this research is to decrease the effect of joint clearance using flexural joints. First, dynamic equations of the slider-crank mechanism are derived using the Lagrange equation, where the mechanism has both the clearance joint and the flexural joint. Moreover, the flexural joints are modeled based on a pseudo rigid body model in which the joint is modeled as a torsional spring. The design of two different types of flexural joints has been done based on defining the optimization problem and optimal design. Design variables of optimization problems include joint geometry and material properties. Minimizing the maximum values of the links' acceleration has been considered the objective function, and the optimization problems have been solved using the Genetic Algorithm. The results show that utilizing the flexural joints in the desired mechanism can reduce the maximum values of accelerations by approximately 90%.