滑卷式壓縮機曲軸之振動分析

Abstract

由於渦卷壓縮機具有高效率，低振動，低噪音，元件個數少，以及高可靠度等優點 ，因此日漸受到冷凍空調界的重視。近年來更因為環保意識的高漲，使得渦卷式壓縮機 在未來將有很大的發展空間。本文旨在研究渦卷式壓縮機曲軸之振動分析，從事理論推 導和電腦模擬，以提供渦卷壓縮機設計之準則。首先，以動態勁性法為分析的基礎，由 樑元素的運動方程式推導出其形狀函數與動態勁性矩陣。然後，將元素的動態勁性矩陣 組合成系統的動態勁性矩陣，再利用模態分析與雙節法計算出自然頻率和模態。接著， 藉由Runge-Kutta法求得曲軸系統的動態嚮應。最後，建立交流伺服馬達帶動曲軸的實 驗，以力╱力矩感測器進行搖晃力與搖晃力矩的量測。

The scroll compressor is promising in the compressor industry due to its high efficiency, low vibration, low noise, few numbers of components, and high reliability. This work aims to investigate dynamics of the crankshaft that drives the scroll in a scroll compressor. Theoretical derivation and computer simulation are undertaken to provide a design basis for the design of scroll compressors, such as geometric design and strength analysis. The dynamic stiffness method is used to analyze the dynamic behavior of crankshafts. First, according to the governing equation of the beam, shape functions and dynamic stiffness matrices are obtained. The dynamic stiffness matrices for elements are combined to form the dynamic stiffness matrix of the entire system. The modal analysis method and the bisection method is employed to solve natural frequencies and mode shapes. The mode-superposition method and the Runge-Kutta method is in turn used to solve the dynamic response of the crankshaft. Finally, Experiments are conducted to measure shaking moments and forces of the crankshaft, which is driven by an AC servo motor.