Summary: | 碩士 === 國立虎尾科技大學 === 機械與機電工程研究所 === 98 === A three dimension analyzing model was built by the use of the finite element method in this research. The applied direction of normal forces on the inner raceways were also considered to study the effect for the strain on the surface of nut. These were used to analyze strains with considering several applied directions of forces formed by the axial load and operating at different rotational speed. This experiment used the strain gages stuck on the surface of nut to establish the real-time strain measuring system and the static strain and dynamic strain were measured by the system. The static strain of nuts was optioned by the rigid testing machine operated at tension and compression on the screw and the nut was fixed on the holder. This experiment also got the axial force and strain curve to compare with the result of dynamic strain measurement and the model analysis of finite element to establish the database of axial force and strain. From the result, the applied axial load and preload are varied the contact directions between ball and raceway when the axial load lower and higher than the preload, and make two slopes occurred in the experiment result , This affects the varying of the surface strain. The analysis method can be established by measuring strain on the surface of the nut to get of strains forces existed between ball and raceway in a ball screw, and variations of dynamic stiffness and preload.
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