Design And Experimental Study Of Smart Bearing Based On A Strain3-axis Accelerometer

Bearing is one of the generic components which is most widely used inmechanical system and its running state will directly influence the safety andreliability of the system. On-line monitoring its running state is an effective method toavoid sudden invalidation which caused by bearing fault.Smart bearing technology is a new technology and new methods has beenproposed and developed in recent years. Smart bearing has the capacity of on-linemonitoring by integrating multi-parameter sensor. These smart bearings areconstructed by integrating sensors with traditional bearings. Piezoelectric accelerationsensor is usually employed as one component of the smart bearing at present in theworld due to its high frequency characteristics. However, condition monitoring andfault diagnosis with smart bearing based on piezoelectric acceleration sensor havesome problems, such as high-frequency noise interference, low treatment efficiency,inadequate monitoring parameters and bearing structure damage.In this paper, fault mechanism for the double row cylindrical roller bearing isexplored and analyzed, and the characteristics of the fault signal are discussed. A newstrain three-axis accelerometer is designed for condition monitoring and faultdiagnosis of bearings. A new Structure of smart bearing proposed in this study isdeveloped by integrating this new accelerometer with speed and temperature sensorsThe experiment proved the Smart bearing can acquire the signals with low frequencyfault information, on-line speed information and temperature informationsimultaneously. The detailed contents and innovative work are summarized asfollows:â‘ The new structure of strain3-axis acceleration sensor is proposed which iscomposed by mass and elastic components in a series-parallel connection. Throughthe establishment of the sensor dynamics model, the optimum parameters is selectedby orthogonal experiment method. The influence of structural parameters on thesensitivity and natural frequency and the3-axis dynamic response of the sensor isanalyzed based on the dynamics equation;â‘¡The3-axis dynamic response of the sensor is analyzed by finite elementmethod (FEM). Verified the validity of the dynamic model by comparing with thesimulation results;â‘¢Completed the new strain3-axis acceleration sensor entity processing, determined the strain three-axis acceleration sensor sensitivity by the sensorcalibration experiment;â‘£The multi-parameter sensor is developed by integrating this new strain3-axisaccelerometer with speed and temperature sensors. Based on which, the new structureof smart bearing is manufactured, which does not damage the integrity and ensure theservice performance of the bearing;â‘¢To test the performance of the new smart bearing, a principle prototype isdesigned and manufactured. The expriments with bearing fault simulation proved theeffectiveness for fault diagnosis on inner ring is validated based on the new strain3-axis accelerometer.The extension of the smart bearing application to other various types of thebearing for on-line state monitoring and fault diagnosis is the developing trend in thefuture, which makes it have a broad scope of application.