渦卷式壓縮機曲軸之主動減振

Abstract

壓縮機在不同轉速時，原來基於曲軸設計速度而配置的配重未必能維持動平衡。有鑑於此，本文之目的在於克服開發渦卷壓縮機瓶頸之一，完成曲軸的新設計，即運用機電整合的途徑有效減少曲軸的搖晃力及搖晃力矩，進行理論分析、電腦模擬及實驗量測。理論方面，利用拉格蘭吉方程式計算出曲軸之運動方程式，並配合以角動量方程式寫出曲軸之搖晃力與搖晃力矩的表示式。電腦模擬方面，使用多體機械模擬軟體DADS，計算曲軸之動態特性。在設計與實作方面，係在原曲軸上加裝兩個動平衡錘，用永久磁鐵所產生的磁力調整動平衡錘的位置，藉以隨時改變曲軸與動平衡錘合成的慣性，並且用六軸力和力矩感測器經由Labview軟體量測曲軸搖晃力和力矩的大小。所提出曲軸的創新設計不僅可應用於冷凍空調方面，而且能夠應用在其它的轉動機械，例如汽車引擎曲軸、渦輪機等等。

This study aims to design and investigate a new crankshaft that drives the scroll in scroll compressors such that dynamic equilibrium is always achieved in spite of speed variation. An electromechanical approach is used to reduce the shaking force and shaking moment. Theoretical derivation, computer simulation and experiments are undertaken. In theoretical study, the Lagrange's equation is used to derive the equation of motion and angular momentum is used to formulate shaking force and shaking moment. In computer simulation, this study constructs models and carries out dynamic analysis using a software for multibody dynamics. In experiments, two dynamic balance pendulums are attached to the rim of the crankshaft. A permanent magnet is installed in the vicinity of each pendulum such that attractive forces can exert on the pendulum. Subject to permanent magnet, the pendulum angles are adjusted to reduce shaking force and moment. A six axes forces/torque sensor reads shaking force and moment via a Labview software to compare simulation results.