The Research And Design On A Torque-Loading Device With Flexure Hinges

The torque measurement occupies an important position in the current research and production, so proper design, use and research of the torque loading device is very important. According to the load calibration of Piezoelectric Dynamometer Drilling which is made from the Sensor Institute of Dalian University of Technology, this paper designs a torque-loading device. The flexure hinges are used as the connecting elements of this device, which could produce a balanced symmetric pure torque under a load force. And floating function can also be achieved. This torque loading equipment with a simple structure is convenient to be manufactured. Besides, the load can be steadily applied.By comparing different designs, an optimal program of the torque loading device bodies is found. Considering the structure, performance and the requirements of floating capacity, three type flexure hinges including arc-type flexure hinge,round-type flexure hinge and reed-type flexure hinge is chosen as the connecting elements. The stiffness formula of round-type flexure hinge is obtained based on the Castigliano's second theorem. The mechanical model of this torque-loading device is developed. Furthermore, considering the infection of tensile and compressive deformation of flexure hinges, the input and output displacement models are developed.According to the basic theory of finite element analysis and the structure characteristics of the torque-loading device, the proper finite element analysis which is suitable for this device is proposed. Through the reasonable setting of boundary conditions under different loads, the torque-loading device's performance under the condition that both no-load and load torque is simulated. The displacement and stress nephogram under different working condition are obtained and the related data are detailed analyzed. The floating capacity of this torque-loading device is evaluated and the reasons are also explained. Modal analysis is also conducted. The optimized structure parameters are acquired through the structural optimization process.In order to verify the performance of the torque loading device, the related experimental torque loading setup is designed. Besides, the experimental analyses are carried out in three areas. The relationship between the loading force and the actual output torque value is acquired. The experimental data and the finite element simulation results are consistent. Above evidences prove the rationality of the design.