Gear Crack Signal Detection Based On Phase-Locked Amplifier

In the modern industry, gear drive is widely used in all kinds of machines,the operating state of gear transmission system is often directly affect the mechanical equipment can work normally, for safe and reliable operation of the machinery and equipment plays a very important role. The failure in gear transmission system parts, accounts for about 60% of the total failure of the gear itself, visible gear has become one of the most critical parts in mechanical transmission. Therefore, the gear and the gear transmission system for condition monitoring and fault diagnosis, has very important practical significance.In mechanical fault diagnosis, the detection signal often contains all kinds of noise, the signal-to-noise ratio of the signal is low, especially when the gear tooth occurred early crack, crack fault signal is very weak emblem, the weak sound or vibration detection, become the early gear fault diagnosis technical problems. In order to realize the accurate detection of weak signal of gear, we design a place coil probe, the probe by a testing coil and a reference of coil, using a bridge circuit for differential amplification detection of weak signal of crack. Signal conditioning circuit adopted a phase-locked amplifier signal detection technology.Based on the analysis of the noise generated by the, the noise suppression method and related technology. Hardware circuit design of the signal detection, including signal collection circuit, preamplifier, pre filter, four-pass amplification circuit and reference signal generating circuit, reference signal phase shift circuit,phase-sensitive detection circuit, etc, And do the simulation experiment, the simulation compare the experimental data and theoretical analysis, found that this approach can effectively realize the weak signal detection. Finally, test the actual hardware circuit, and once again proved that the technology can well realize signal detection.