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EE-240 Falhas em Máquinas Rotativas. Desgastes em Caixas de Redução. PHM Challenge. Bearings Inner/Outer/Ball. Tacho 10 pulses/revolution. 32. 48. Out Accelerometer. 96. Load High / Low. Shaft Speed 30/35/40/45/50 Hz. 80. In Accelerometer. Gears Chipped/Broken.
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EE-240 Falhas em Máquinas Rotativas
Desgastes em Caixas de Redução
PHM Challenge Bearings Inner/Outer/Ball Tacho 10 pulses/revolution 32 48 Out Accelerometer 96 Load High / Low Shaft Speed 30/35/40/45/50 Hz 80 In Accelerometer Gears Chipped/Broken (32/96) x (48/80) = 1/5 Shaft Imbalance/Bent/Bad Key
Feature Extraction Conditioned Raw Signal rms Kurtosis Delta RMS Crest Factor Enveloping DC Offset Removal Signal Conditioning Accelerometer Time Synchronous Averaging FM0 TSA signal Tacho Fundamental Shaft and Mesh Frequency Removal Band Pass around Mesh Frequency NB4 NA4 NA4* Mesh Signal Residual Signal 1st Order Sideband Removal FM4 M6A M8A Difference Signal
Features TSA Signal Raw Signal Mesh Signal Residual Signal Difference Signal
Features Medida geral de intensidade da vibração, sem apontar o componente degradado Indica presença de picos, ocasionado, por exemplo, engrenagem com dente quebrado Em geral, entre 2 e 6. Valores acima de 6 sugerem defeitos que causam picos acentuados Permite visualizar a presença de harmonicas de frequencias específicas, além de indicar a morfologia dos picos.
Features Progressão de problemas com dentes de engrenagens não varia a Mesh Frequency, mas tende a aumentar a amplitude
Features Variadas propostas de features associadas a surgimento de picos nos sinais.
S - Rotation Speed FTF – Fundamental Train Frequency BPFO – Ball Pass Frequency of the Outer Race BPFI - Ball Pass Frequency of the Inner Race BSF - Ball Spin Frequency FTF = S (1 – Bd/Pd) / 2 Bd = Ball Diameter BPFO = S Nb (1 – Bd/Pd) / 2 Nb = Number of Balls BPFI = S Nb (1 + Bd/Pd) / 2 Pd = Pitch Diameter BSF = S Pd (1 – Bd^2 / Pd^2) / 2 Bd
S Ball Pass Frequency of the Outer Race BPFO = S Nb (1 – Bd/Pd) / 2 Exemplo: Nb=12; Bd = 1.0; Pd = 5.0; S =3000/60Hz T_eixo = 1/S = 0.02 BPFO = 240 Hz T_outer = 1/BPFO = 0.00416 N_pass_ball = 0.02/0.00416 = 4.8 %_ball = 4.8/12 x 100 = 40%
Ball Pass Frequency of the Inner Race BPFI = S Nb (1 + Bd/Pd) / 2 Exemplo: Nb=12; Bd = 1.0; Pd = 5.0; S =3000/60Hz T_eixo = 1/S = 0.02 BPFO = 360 Hz T_outer = 1/BPFO = 0.00277 N_pass_ball = 0.02/0.00277 = 7.2 %_ball = 7.2/12 x 100 = 60%
Ball Spin Frequency BSF = S Pd (1 – Bd^2 / Pd^2) / 2 Bd Exemplo: Nb=12; Bd = 1.0; Pd = 5.0; S =3000/60Hz BSF = 120 Hz
S GMF GMF = Gear Mesh Frequency = S * T S = Speed T = Number of Teeth Exemplo: S = 50 Hz T = 24 dentes GF = 50 x 24 = 1200 Hz
Geração de Subharmônicas 3N dentes 2N dentes