電鑽齒輪箱的動態模擬與振動分析

Abstract

本論文旨在運用多撓性體機構分析的方法進行電鑽齒輪箱的動態模擬和振動現象分析。首先利用有限元素軟體給定的適當的邊界條件以求得行星齒輪系內部各元件的振動模態，進而結合撓性多體機構軟體進行動態模擬，建立齒輪箱內各齒輪均為彈性體時的動態模式，從而計算齒輪間的受力，齒輪囓合期間對系統的動態影響，以及整體的振動行為。俾在高轉速、高負載的運轉要求下，減少齒輪箱的振動和延長其使用壽命，在設計過程預測動態的性能，分析不同設計參數對振動的影響，達到合乎需求的設計。結果顯示電鑽外殼的搖晃力與搖晃力矩隨齒輪剛性減小而增加，當所有齒輪的材料均為碳鋼時，所造成的振幅比剛性小的塑膠齒輪小。馬達轉速減少時，齒輪箱上振幅並不為之減少，但頻譜呈現的頻率隨之往低頻移動。本文並且推導了鑽孔時的負載公式，計算出工作時的機械效率。

In this study, finite element analysis and flexible multibody analysis are used to perform dynamic simulation and vibration and vibation analysis for the gearbox in an electric drill. First,with appropriate boundary conditions, finite element analysis is carried out to calculate natural frequencies and deformation modes of each component in the planetay gear train. Second, finite element data are fed into the flexible multibody program to execute the dynamic analysis. In the gearbox model, kinematic relations among flexible gears are prescribed. Deformation and contact force of meshing gears are incorporated. This study aims to find criteia to relations among flexible gears are incorporated. The results show that the shaking force and torque increase when gear stiffness decreases. The vibration amplitude of the gearbox employing carbon steel gears is smaller than plastic gears. Decreasing the motor speed will not reduce the vebration amplitude, but the vibration spectrum shifts to lower frequency. In addition, this study derives loading equations and calculates mechanical efficiency when drilling subject to friction torque.