Design, Fabrication And Experimental Study Of Two New Types Of Flexible Joints

With the development of modern machinery in the direction of high speed and high precision, the problem of impact, friction and lubrication caused by the gap between the rigid joint has become more and more prominent. In order to increase the stability, precision and life of machines, flexible joints and compliant mechanisms with no gap and abrasion have been increasingly applied to micro manipulator, precision optical instruments, aerospace vehicle and industrial equipment and other occasions. Most of the existing flexible joints are designed according to the small deformation and high precision requirement of the micro operation mechanism. It has important theoretical and practical significance to make better use of flexible joints to improve the performance and service life of large size and large distance machine. This paper investigated this topic.Firstly, with the index of off-axis stiffness, axis drift, movement precision, new schemes of flexible joint have been designed according to the idea of symmetrical. The modeling and motion simulation of flexible joints have been carried out by modeling and simulation software such as Adams, ANSYS and Solidworks. By comparing the simulation results, the Y type and X type flexible joint with better performance are proposed.Subsequently, material selection, fabrication and measurement of X type and Y type flexible joint have been carried out. The processing technology of flexible joints has been solved to improve the processing and installation precision. The measurement of the axis drift of flexible joints has been carried out and the experimental data is analyzed. The results show that the rotation angles of Y type and X type flexible joint are both bigger than 45 degree, and the motion precision, the off-axis stiffness and the stability of the X type flexible joint are better than those of the Y type flexible joint.Finally, the rigid joints on parallel robot with three degrees of freedom are replaced by flexible joints, and trajectory tracking experiments of the robot with rigid joint, single leaf spring, Y type flexible joint and X type flexible joint have been carried out. By comparing with the rigid joint parallel robot, The experimental results show that these three kinds of flexible joints can replace the rigid joint, effectively reducing the impact of the robot, improving the movement precision of the robot; Single leaf spring has the disadvantages of small off-axis stiffness, large vibration and so on; The trajectory error of Y type flexible joint robot is smaller than single leaf spring, but the off-axis stiffness is lower, and the robot is still vibrate; The trajectory error of the X type flexible joint robot is smaller than that of the robot with rigid joint, single leaf spring and Y type flexible joint,and the off-axis stiffness of X type flexible joint is higher than that of the Y type; X type flexible joint can replace the rigid joint of the robot very well, effectively reducing the impact of the robot, and greatly improving the precision of the robot.