Bearing Fault Detection in a Low Speed Shaft Using Shock Pulse Sensor

Large megawatt wind turbines produce electricity at very low speeds for long periods of time. The bearings used in the turbine are susceptible to failure due to prolonged exposure to cyclic loads. It is important to diagnose bearings defects early to prevent large failures in advance. However, when the rotation speed of the shaft is low and the load is small, it is not easy to detect a minute abnormal vibration from a small defect by a general accelerometer. When a slight collision occurs between the bearing and the inner/outer races, the shock pulse sensor is resonated and generates a defect signal. In this study, a low - speed rotating machine module was fabricated and made a small defect that is difficult to detect signal with accelerometer. With this module, we examined whether a shock pulse sensor can detect a minute defective signal.