Whatever you do, you can go faster and easier if you have a strong foundation. Today is the second ABC reading in Vibration Analysis. As I told you before, I have outlined the Frequency, FFT (Fast Fourier Transform) and the concepts of parameters for vibration measurements.
Related blog link: https://blog.naver.com/mobilio2/221883535595
Frequency is a measure of the percentage of device or part movement that occurs in Hz (or CPM per minute) per second. Think about the piano that many people enjoy. Each sound that occurs when you press a piano keyboard can be expressed with a unique frequency and this frequency is constant, so it always sounds the same. If you press the two or three keys at the same time, you will hear a beautiful, mixed sound. In technical terms, each sound is combined with its own frequency and amplitude, which sounds like a complex sound. Like the piano, every device in the industry has a unique vibration pattern. And it can be as wide as the piano. Vibration analysis is the process of analyzing the instrument’s unique vibration patterns and characteristics and identifying the potential for failure.
Frequency – 모빌리오
FFT (Fast Fourier Transform) ?
FFF is called the high-speed Fourier transform technique or algorithm, which means the mathematical calculation method used to convert signals from the device into frequencies. The FFT chart is a fundamental element of vibration analysis by diagnosing instrument failures based on converted frequency data and using amplitude information to assess instrument failure strength.
Fast Fourier Transform image
Parameters used to measure vibration (Parameter)
So what are the parameters for vibration analysis? We’re going to take measurements using three variables. The utilization of each parameter depends on the frequency band, so please refer to the following.
Acceleration: attach greater importance to higher band frequencies. An effective parameter for checking bearing condition.
Velocity: Can be applied to both high-band and low-frequency analysis tasks. Speed is a variable that relates to the destructive power of vibration and is more important.
Displacement: This parameter is suitable for frequency analysis in low bands. It is known to be effective in dynamic balancing, orbiting and ODS (Operating Deflection Shapes) analysis.
(ODS is a technique for measuring the displacement of the device/unit in motion, and it measures the vibration of each of the major parts of the device to analyze the vibration using the relative phase difference before and after the vibration. Let’s think of it as a car. I felt a terrible vibration in my car on my way to work, so I stopped by the garage. But when I go to the garage, I don’t get vibrations. However, the vibrations are back to normal after work is over 80 kilometers per hour. In this case, it should be analyzed while the car is running.)
(자료 출처: ww.erbessded-instruments.com)
In the next post, we will talk about a new technique (technology) for vibration analysis.
(주)모빌리오는 예지보전솔루션 전문 기업입니다.
Mobilio is an engineering company for the Predictive Maintenance Solution(주)모빌리오는 스마트 팩토리와 스마트 빌딩의 최적화된 운영.관리를 위한 예지보전 솔루션을 제공해 드립니다. Mobilio is an engineering company providing solutions and services for the predictive maintenance.www.mobilio.io