Vibration Analysis Technique for Small Rotating Machines and its Application

Vibration and noise problems are common to small, high-speed rotating machines such as electric vacuum cleaners and small blowers. When these machines are used in the home, reduced vibrations and noise are very desirable, Engine order analysis is a well known method to measure vibration and noise characteristics of rotating machines. However, for small rotating machines, attachment of a rotating pulse generator to the rotating shaft to detect rotating frequency is generally difficult. Even if attachment is possible, much time is taken in preparation for the measurements. A new rotating frequency estimation method without a rotating pulse generator is proposed and its accuracy is discussed. Then, a new engine order analysis technique using the frequency estimation method is introduced and applied to analyze vibration and noise from an electric vacuum cleaner.