INVESTIGATING METHOD OF LOAD-DEPENDENT OSCILLATION OF ROTARY MACHINE

摘要

PURPOSE:To measure the natural oscillation frequency and attenuation factor safe tolerance of a rotary machine by varying a load condition stepwise while holding the rotating speed of the rotary machine, and calculating an attenuation factor for permissible excitation count value from oscillation response data in every load state. CONSTITUTION:When this excitation test is conducted, the oscillation frequency is varied gradually within a target range and oscillation response is measured. Data on it are collected and analyzed to calculate an attenuation factor or permissible oscillation coefficient K as mentioned below. Then while the rotating speed of the rotary machine is held constant, the load is increased to, for example, 1/4, 2/4, 3/4, and 4/4 and stationary operation is performed for a specific time in every load state; and the oscillation frequency is varied gradually within the target range to measure the oscillation response. Data on it are collected and analyzed to calculate an attenuation factor xsi or permissible oscillation coefficient K. Thus, the natural oscillation frequency and attenuation factor safe tolerance of the rotary machine are calculated.