Design, Development, and Application of a Compact Flexure-Based Decoupler With High Motion Transmission Efficiency and Excellent Input Decoupling Performance

Here, we present the design, development, and application of a compact flexure-based decoupler, which is commonly utilized in compliant parallel mechanisms (CPMs) to transmit the motion of an actuator and protect the actuator from suffering transverse loads. The kinematic structure selection of the decoupler is first introduced. Then, several specific design requirements are proposed to guarantee its key performances. On this basis, the detailed structures of each part of the decoupler are discussed and the geometric parameters are optimized to obtain an ideal decoupler. The performances of the optimized decoupler are verified with finite element analysis (FEA). According to the optimized results, a prototype is fabricated and experimental tests on the input axial stiffness and natural frequency are presented. Both FEA and the experimental results demonstrate the excellent performance of the decoupler. Finally, the proposed decoupler is applied in the development of a 2-DOF CPM. The definition and calculation expression for the input coupling degree (ICD) of the CPM are given, and its geometric parameters are optimized to reduce the ICD. A prototype of the CPM is fabricated for the performance evaluation. A new method is proposed to test the ICD of the CPM by detecting the variations of axial forces along the two axes. Contouring properties of 2-D trajectories are also provided. The experimental results not only demonstrate the excellent decoupling performance of the CPM but also verify the effectiveness of the adoption of the decoupler.