| The thermal modeling of high speed spindles and the analysis of their temperature fields, thermal characteristics, and bearing defect signals are presented. The results provide an understanding of the thermal situation of high speed spindles and introduce practical methods for assisting in the analysis and design of high speed spindles.; In this study a thermal modeling technique based on the finite element method was developed for the high speed spindles. The bearing loads, the bearing heat generation properties, the spindle structure meshing, the spindle thermal conduction and convection, and the bearing defect characteristics were investigated. An improved heat generation model of high speed angular contact ball bearings was formulated. Two high speed spindles were modeled and analyzed for illustration and verification. The models were verified against measured temperatures and good agreement between the computational and experimental results was found. An infrared temperature measurement technique was developed for the temperature measurement inside the cavities of the rotating components. Additionally, the effect of spindle speed, bearing preload, water cooling of the spindle bearings, oil-air lubrication oil drop rate, and air supply pressure were investigated. Model evaluation based on the measurement of a real bearing seizure yielded bearing catastrophic failure load and temperature and showed the large value of the transient thermal load.; Bearing defect monitoring through measuring bearing vibration spectrum,bearing temperature variation and acoustic emission was also investigated in this work. An acoustic emission signal demodulation method was implemented. The measurement of bearing vibration signal shows that this method is effective for bearing monitoring under condition of strong background noise.; 1... |
