Bearing Detector Based On The Impact Of The Pulse Sensor Conditioning Circuits

Machinery plays a very important role in the national economy and people's daily lives. The rolling bearing is one of the important parts of mechanical equipment. According to statistics, about 30% of the faults in production are caused by the rolling bearing failure. Research and application of equipment condition monitoring, fault detecting, and status forecasting techniques can not only detect failures in the early stage and avoid vicious production accidents, but also fundamentally solve the problems of both inadequate and excessive repairing during the current regular maintenance of equipment.The Shock Pulse Method (SPM) which was invented in the late 1960s is a typical method, among with others, to detect the bearing faults. It detects rolling bearings' working status and damaging degree if any, by measuring the effective wave amplitude at the point of the bearing seat. Its hardware implementation comprises a SPM transducer and appropriate conditioning circuitry which includes an amplifier, a 30kHz-40kHz band-pass filter, and an AD transducer.This paper firstly has a study on a rolling bearing-detector invented by a certain company and coded with A By disassembling and studying the detector, the present author conducts a research both on the whole SPM signal processing and on the solution of the practical electric circuit. Meanwhile with the advantages of signal acquisition device, digital oscilloscopes and other test equipments the author collects the real-time data and finally analyses the existing defaults of the detector which lays a foundation for the further study on the new digital detection system.Since in reality the rolling bearing works in a considerably much noisier environment, and the frequency characteristics of different transducers and electric devices have some differences with theory, the paper tests the frequency response of the SPM sensors through experiments. Basing on the frequency as well as SPM signal processing theory the present author designs a practical amplifier circuit which ensures a signal-amplifying capability, instauration and useful signals'not being covered by the noises, and band-pall filter to match the actual condition. Then a satisfactory testing result is obtained on the real rolling bearing platform. With the help of the newly designed circuit, the detecting device successfully detects bearings of different damaging degree and by means of digital oscilloscope experimental data are collected which, in the digital signal processing, testifies the effectiveness and data-testing correctness of the circuit.In conclusion, as far as rolling bearing faults detection is concerned, this paper employs the typical SPM sensor and the SPM signal processing method to design an amplifier circuit and a filter one. By adopting the digital oscilloscope the present author obtains data which lay a reliable foundation for the digitalization processing of FPGA. Therefore, a high-speed and precise rolling bearing faults detection method is achieved which bears considerable significance in such fields as condition monitoring, faults detecting and status forecasting, thus a broad application prospect.