1.5 kW 유도전동기 엔드링 기공이 회전체 진동 및 베어링 내구성에 미치는 영향 분석

Abstract

This paper presents the results of rotordynamic analyzing the effect of the end-ring porosity of a 1.5 kW induction motors on the rotor vibration and the bearing durability. Firstly, the end ring porosity shape of the induction motor was simplified by the porosity cross-sectional area (S) and porosity distribution angle (θ), and a mathematical model was established to calculate the amount of unbalance. The amount of unbalance due to porosity shape was analyzed through a mathematical model. As a result, it was confirmed that the amount of unbalance significantly increased to more than the balancing grade G40 by S and θ. In general, the proper balancing class for induction motors is G2.5. Second, a rotordynamic analysis model was developed that can predict the vibration characteristics of rotor. In addition, the analysis model was validated through the modal test. Finally, the vibration characteristics of the rotor were analyzed according to the amount of unbalance and phase angle through the rotordynamic analysis. As S decreases, the maximum rotor amplitude linearly decreased and the bearing life increased. As θ increases, the maximum rotor amplitude nonlinearly decreased and the bearing life increased. As the phase angle increases, the maximum rotor amplitude decreased by 75% and the bearing life increased 63 times.