Research On On-line Detection Technology Of Running Gear State Based On Fiber Grating

Gear is the main indispensable component of the rotating machinery system,and there may be a variety of faults in the use of the gears,which may lead to serious mechanical accident if effective means can't be taken timely.Therefore,it is very important to study the running state of gear on line detection technology to ensure the safe operation of rotating machinery and reduce the loss that gear fault brings.Based on full investigation of the research status of gear detection,this study makes use of the advantages of optical fiber sensing technology,such as remote passive and multi point measurement with one fiber.This study takes the gear bending strength as the object to study the gear on line detection technology based on fiber grating sensors,and makes a preliminary analysis and experimental study on the common faults of gear transmission.Firstly,according to the theoretical mechanics and material mechanics analysis,the stress and strain of gear is analyzed when transmission;then according to the different external action on FBG(Fiber Bragg grating),the strain characteristic of FBG is analyzed,and the concrete mathematical model is deduced.And three arrangement modes of the FBG sensing element are designed on the gear(Along the root axis parallel arrangement,Along with the tooth axis angle arrangement,Tooth side arrangement),and the corresponding calculating formula of the tooth root bending strength is deduced.Secondly,Detection method for gear tooth root bending stress is studied.According to the three designed arrangements of FBG,the static load experiment of gear tooth root bending stress is respectively conducted,the result shows that all the three kinds of methods can accurately measure the tooth root bending stress,and have a linear output and good stability.From three aspects of complexity,sensitivity and error,the advantages and disadvantages of the three methods are compared,and the result shows that the sensitivity and stability are best when the FBG is arranged in the position of the tooth side,and it is more convenient to realize online detection.Finally,taking running gear as the object,on-line detection of tooth bending stress and fault diagnosis technology experimental research are conducted.On-line detection system and experimental platform for gear running state is built.In addition,the corresponding monitoring software is developed by using LABVIEW,and the real-time monitoring of the gear running state is realized.According to the tooth side arrangement,the on-line detection of gear tooth root bending strength and fault diagnosis simulation experiment is conducted on the experimental platform,results show that the use of FBG sensing technology can not only realize on-line detection of the tooth root bending stress,and can realize the initial identification and diagnosis of gear common faults.