Thermal performances on angular contact ball bearing of high-speed spindle considering structural constraints under oil-air lubrication

To predict thermal behaviors of high-speed angular contact ball bearings is essential for operating precision. Particularly, the characteristics of high-speed angular contact ball bearings depend on their thermal performances. However, most researchers only considered the convection effect between housings and ambient air, whereas the coolant/lubricant and specific structural constraints effect were not integrated. In this investigation, the load equilibrium model of angular contact ball bearings with thermal expansion was first established to calculate bearing loads. The coolant/lubricant, radial and axial structural constraints and assembly constraints were fully taken into account to study the heat generation and transfer of bearings, and then a novel muti-node thermal network model for angular contact ball bearings was proposed. Applying this muti-node model, an integrated comprehensive thermal grid model for the front bearing of high-speed spindle and its surroundings was established to forecast the bearing temperature. Next Euler's method was employed to solve the equations by Matlab and the node temperature was calculated. Finally, the bearing temperature rise was tested and the comparative analysis was made with the numerical results. The results indicate that both series of results agree well. So, the thermal grid model established is verified.