| Summary: | 碩士 === 國立中正大學 === 機械系 === 87 === The transient vibrations of a high speed feed drive system are investigated. An analogue vibratory equivalent model with multi-degree of freedom assembled with spring, mass and damper is used to simulate the dynamic behavior of a feed drive system. An important feature in this study is that the work table is able to travel at variable speed and can be brought to a halt at any desire position. The equations of motion of the work table with finite size and the supporting structure are obtained using the Newton's Law. Numerical results of the vibration response are obtained to illustrate the theoretical predictions. Results show that increasing the moving speed of table causes large vibration for the system. When the table travels variable speed along the guide way, the symmetric and continuous motion program leads to less vibration for the system. Increasing the damping capacity of whole system decreases the vibration of table and guide way. However, increasing the damping capacity between the table and guide way mostly decreases the vibration of the table but has poor effect on the vibration of the beam. Furthermore, increasing the damping capacity between guide way and the ground decreases the vibration not only the table but also the guide way. While the vertical displacements of the table and guide way are small while the stiffness of the system is large. There is an optimum stiffness value where the horizontal displacement of the guide way after the feed stopped can be minimized. As far as the size and mass center position of the table are concerned, results also show that an optimum ratio between length of table and that of the guide way minimizes the vertical vibration of the table.
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