Dynamical Investigation of Cam-Follower Profile Under Space - 100 to + 120°C Temperature Condition

Abstract

Cam-follower mechanism efficiency in production of desired motions has been proved along the history of space missions. In this paper, according to pre-specified spatial condition of wide temperature variations between -100 and +120 Celsius degrees, some new and innovative cam-follower profile designs are presented. In the first follower mechanism, through rotating a connected screw to a servomotor, changes in length of the moving follower on cam is compensated with respect to the temperature changes of certain spatial conditions. In the second design, an inclined surface cam is equipped with an active controllable follower. As the third suggestion, the design with an inclined cam surface is optimized by investigating the length of the shaft connected to the cam. In the fourth model, a new design is proposed by changing the shaft's material from aluminum to titanium and a modified design is presented. The proposed designs are investigated and compared using the analytical solutions and optimization tools using MATLAB and ANSYS. The purpose of this study was to identify the effect of profile type on the dynamic behavior of the mechanism under the effects of a temperature difference of -100 to +120°C in space condition. It is concluded that changing the length of the follower, using an inclined cam surface and optimizing the length of the shaft connected to the follower are all effective solutions to the cam's volume variation problem. The results also indicate that for solving the problem of the volume variation of the cam-follower mechanism a combination of the proposed designs is optimal. Moreover, among the presented designs, the mechanism with an inclined cam surface with an aluminum shaft is shown to have the highest precision and performance with respect to the other three.