Design And Characteristic Analysis Of Rotary Head Of Parallel Robot

In recent years, parallel robot is a research focus. Compared with serial robots, parallel robot has a high precision, high stiffness, high carrying capacity and fast transient response, and the range and areas of its application is increasing. The entire and systemic research on the parallel robot is of great importance both on theory and application. It is of great both theoretical significance and practical value to research on the parallel robot comprehensively and systematically.Rotary head is one of the most important components of the parallel robot, its performance has an important effect on the precision of the workpiece and processing efficiency. Rotary head has a complex structure, composed of many parts and a small size, so it is difficult in ensuring the stiffness and hard to drive and control. These aspects seriously affect its design and production. This paper mainly designs and researches on the 45° nutating head. And the forward and inverse kinematic solutions of the A/C biaxial rotary head, and analyzes the static-dynamic characteristics for the 45° nutating head.Firstly, this paper concludes the configuration classification of five degrees of freedom parallel robot, which determine the rotary head with two rotation degrees of freedom, and then summed up the general layout scheme Established the kinematics model of the A/C biaxial rotary head and the 45° nutating head. The forward and inverse kinematic solution of the two rotary heads was calculated. This paper selects 45° nutating head. And then designs the 45° nutating head in detail.Secondly, this paper creates 3D solid models for the 45° nutating head by Pro/Engineer, then imported them into ANSYS to generate the finite element model, because the structure of the 45° nutating head is complex, simplify the model based on the characteristics of static analysis. According to actual milling parameters, the milling force was calculated out, and the results of static analysis were discussed.Finally, this paper analyses the kinetics characteristics of the 45° nutating head. And introduces the basic theory of modal analysis, and then analysis the modal of the head. Then discuss the modal analysis results and its influence on the dynamic characteristic of the head. Considered the influence of the alternating force load, analysis the harmonic response of the nutating head. Before that, introduces the basic theory of harmonic response, calculates the size and frequency of the alternating milling force. According to the result of the harmonic response, obtains the steady-state response under the action of the alternating cutting force.