Optimal Design of a QZS Isolator Using Flexures for a Wide Range of Payload

This paper presents an optimal design of QZS (Quasi-zero stiffness) isolator using flexures for wide range of payload. The QZS isolators have both appreciable static stiffness for gravity compensation and very small (theoretically zero) dynamic stiffness for vibration isolation. Since the stronger vertical spring brings out more gravity compensation within a given stroke of the gravity compensation, the QZS isolator need to have strong vertical stiffness to support wide range of payload. First, the dynamic model of QZS isolator using flexures is illustrated based on the previous non-dimensional analysis of flexure. Then, some design considerations for flexure are discussed and optimal design problem of the QZS isolator is formulated mathematically to maximize the stiffness of the vertical spring As a result, optimal shape ratio of flexure to maximize stiffness of the vertical spring can be determined. Finally, the design procedure for flexure of the QZS isolator is summarized and illustrated with a design example.