| 摘要 |
PURPOSE:To exactly diagnose the abnormality of a speed change gear train by deciding that abnormality is generated in a small gear and a large gear, when a signal for showing a fact that outputs from a first and a second BPFs exceed a reference value is outputted from both of two first and second comparing means, respectively. CONSTITUTION:AE sensors 1, 11 are installed in bearing parts of a small gear and a large gear of a speed change gear train, respectively, and as for AE signals a11, a21 detected from the sensors 1, 11, only components of rotational frequencies f1, f2 of the small gear and the large gear are allowed to pass through amplifiers 2, 12, envelope detection circuits 3, 13, and BPFs 4, 14 and 5, 15. Subsequently, AE signals a13, a23 and a14, a24 outputted from the BPFs 4, 14 and 5, 15 are inputted to comparing circuits 6, 7 and 16, 17. Next, in the circuits 6, 7 and 16, 17, the signals a13, a23 and a14, a24 and reference values S1, S2 and a3, a4 are compared, and in the case of exceeding the reference value, signals b1, b2, c1 and c2 are outputted, respectively. Also, in AND circuits 8, 18, when OR of the signals b1, b2 and c1, c2 is formed, and in exclusive OR circuits 9, 19, when exclusive OR of the signals b1, b2 and C1, C2 is formed, an abnormality signal is outputted, respectively. |
