| Differential planetary roller screw is a new linear drive mechanism. Its basic theory research is insufficient in China. In order to promote its application in aerospace precision servo drive, a research has been made on the motion, engagement, contact deformation and bearing characteristics of PWG differential planetary roller screw in this dissertation.First, on the basis of analyzing its structural characteristics and working principle, the relationships between the key structural parameters and the lead of PWG were discussed. The meshing analysis was carried out by using the basic knowledge of engagement principle. And the influence of differential effect on the precision of the lead was analyzed. A precision test equipment of differential planetary roller screw was designed to measure its accuracy, and verified the correctness of the theoretical calculation.Second, the elastic-plastic contact deformation of differential planetary roller screw was discussed according to the Hertz theory and the theory of elastic-plastic mechanics. The critical load to elastic-plastic yield was solved based on the yield criterion of metals. On the basis of the elastic-plastic contact deformation, the load distribution was analyzed according to the deformation coordinate relationship. Then the finite element analysis was made for the elastic-plastic contact by ABAQUS. The simulation results and the theoretical results were compared, which showed the correctness of models.At last, based on the study of the elastic-plastic contact deformation and the load distribution, the rated static load and the rated dynamic load of differential planetary roller screw were researched. The transmission efficiency was calculated, and a transmission efficiency test device was designed. The experimental value was compared with the theoretical value of transmission efficiency, and the test results agreed well with the calculated results. |
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