BEARING DIAGNOSIS SYSTEM AND BEARING DIAGNOSIS METHOD

To provide a bearing diagnosis system with which, even when a measurement apparatus of slow sampling frequency is used, it is possible to capture characteristic high-frequency vibration of a bearing and monitor a state of the bearing.SOLUTION: There is provided a bearing diagnosis system comprising: a digital converter for digitally converting, with a lower sampling frequency than a characteristic vibration frequency of a bearing, the vibration waveform outputted by a vibration measuring sensor installed in the vicinity of a bearing of a rotary machine; an FFT computing unit for Fourier-transforming the vibration waveform having been digitally converted by the digital converter; a frequency shifter for mapping a spectrum having been Fourier-transformed by the FFT computing unit to a high-frequency region that includes the characteristic vibration frequency of the bearing; and an inverse FFT computing unit for inversely Fourier-transforming a spectrum of the high-frequency region having been mapped by the frequency shifter and thereby restoring the characteristic vibration of the bearing.SELECTED DRAWING: Figure 1 【課題】 低速なサンプリング周波数の計測機器を用いた場合であっても、高周波数の軸受の特徴振動を捉え、軸受の状態を監視できる軸受診断システムを提供することを目的とする。【解決手段】 回転機械の軸受の近傍に設置した振動計測センサが出力する振動波形を前記軸受の特徴振動周波数より低いサンプリング周波数でデジタル変換するデジタル変換器と、該デジタル変換器でデジタル変換された前記振動波形をフーリエ変換するＦＦＴ演算器と、該ＦＦＴ演算器でフーリエ変換されたスペクトルを、前記軸受の特徴振動周波数を含む高周波数領域に写像する周波数シフト器と、該周波数シフト器で写像された高周波数領域のスペクトルを逆フーリエ変換することで前記軸受の特徴振動を復元する逆ＦＦＴ演算器と、を具備する軸受診断システム。【選択図】 図１