| Summary: | 碩士 === 國立虎尾科技大學 === 機械與機電工程研究所 === 100 === Ball screw is a kind of accuracy linear transmission component. But with high rotational speed will cause more thermal displacement effects than low rotational speed. It produces different degrees of thermal expansion and a principal affecting reason of the positioning errors. A Finite element method (FEM) is used to construct a thermal analyzing model of nuts under frictional heating effects. The heat source model used ball screw kinematics to calculate a range of contact angle and average heat flux, the ball contact angle is considered as a normal distribution conditions. Boundary conditions of the analysis model have considered reciprocation by air convection effect. Thermal deformation analysis of the screw and nut were considered with internal contact geometry and temperature rise thermal effects, respectively.
In the experiments, In-situ testing is held in hatchback machine of a ball screw system. This work puts the thermal couples inside the nut in order to instantaneously measure the variation of temperature, then it is can be used in the comparing with the simulation and experiment. Finally, results from experiment and simulation were confirmed for verification. Using the proposed model incorporating thermal is placement is easy applied in analysis of temperature rise control system.
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