Research On Distributing Bearing Temperature Measurement Technology Based On Optical Fiber Grating Sensor

The bearings are widely used in aviation, aerospace, vehicles, ships and other important areas. They are one of the base parts of the widely used in rotating machinery and playing the role of supporting and transmiting force, while bearings are also the most easily damaged parts. Various studies have shown that nearly about30%of equipment failure is caused by bearing damage, so bearing condition monitoring plays an important role on the normal operation of business machinery and equipment. Bearing monitoring are mainly about the monitoring of vibration condition and temperature status of bearings. As the bearing vibration signals in the study of the vibration state is difficult to obtain, while temperature signals is easy to get because heat source is a clear signal in the study of temperature status. That is why so many scholars later change their research from bearing vibration monitoring to bearing temperature condition monitoring.Traditional temperature sensors used in the traditional condition monitoring of bearing temperature, such as thermistors, thermocouples and so on, are susceptible to electromagnetic interference and along with the hysteresis, and are not easy for distributed temperature field measurement, so they can not meet the requirements of distributed bearing temperature measurement.The fiber grating is a new sensitive passive component, in addition to the advantages as ordinary sensor does, it has the characteristics of not producing electromagnetic interference and less susceptible to electromagnetic interference, it also can use WDM technology connecting multiple gratings of different wavelengths in an optical fiber grating for distributed measurement, avoiding the shortcomings of traditional sensor complex wiring. Bearing temperature measurement in the rotating machinery and equipment need to be laid a large number of sensors, meanwhile the sensors can not affect the normal work of the machinery and equipment. Therefore, using the fiber Bragg grating sensor technology in complex rotating machinery and equipment can meet the requirements of bearing temperature field measurements. In this paper, the fiber grating sensing technology is used in bearing temperature field measurement system for rotating machinery and equipment. The results of the paper made in this article are as follows:(1) Fused biconical tapered optical fiber splitter is common in optical fiber communication connector, through the Spectroscopic experiments on one splitting into two, four and eight optical splitter, I have mastered the spectroscopic properties of the splitter: the number of optical splitter splitting relates with the light source power. This paper analyzes the discipline between the fiber bending radius and bending loss:the greater the bending radius, the smaller the bending loss.(2) A Fiber Bragg grating bearing temperature sensor is designed for the distributed temperature field measurements of rotating machinery and equipment; Through the ANSYS Finite Element Simulation of temperature field, I raised the structural optimization of the temperature sensor; A static temperature calibration experiments of the sensor shows that:The temperature(x) of the grating which packaged in the sensor have good linear relationship with its center wavelength (y); Assessment test was taken for the accuracy, sensitivity, stability and repeatability of the Fiber grating bearing temperature sensor; A distributed bearing temperature measurement system is designed based on fiber grating sensing technology.