The Analysis of Excitation Sources and the Dynamic Responses in Lift Systems

Traditionally, lifts were equipped with machine rooms that contained the drive unit and hoisting motor. Machine room-less lifts (MRL) now have these components located in the shaft and are required to achieve acceptable values of vibrations, airborne noise and structure borne noise. The transmission paths of noise and vibration indicate that they originate from various sources. The possibility to predict the response of systems and sub-systems can reduce development time and allows for specific design changes at an early stage. In the design phase the calculation of system natural frequencies and sub-system natural frequencies enables identification of resonance conditions. The identification of fundamental and harmonic frequencies of all components within the lift system enables quick allocation of excitation sources. The following discussion will briefly examine simulation techniques and identify the basic formulas involved in identifying excitation frequencies. The paper continues with methods of data analysis techniques.