Analysis of the heat transfer performance inside cavity of the counter rotating dual rotor bearing

Purpose: This paper aims to analyze the temperature field and the heat transfer performance of the counter rotating dual rotor bearings (CRDRB) based on the air phase flow field at different speeds to provide effective support for the lubrication and the thermal design of CRDRB. Design/methodology/approach: In this study, taking H7006C angular contact ball bearing as an example, based on the flow visualization technique and the thermal analysis methods, the effects of outer ring speed on the air phase flow field, the temperature field and the heat transfer in bearing cavity were investigated. Findings: Results indicated that there were more complex turbulent air vortices in CRDRB cavity. Turbulent cyclones in critical contact zone reduced the heat dissipation capacity of air. Compared with single rotor bearing with a static outer ring, the average heat transfer coefficient reduced by 11.78% and the average temperature raised by 3.06 K inside CRDRB cavity. Under the influence of outer ring rotation, the high temperature area in ball-inner raceway contact zone and pocket raised and reduced by 160.13% and 30.48%, respectively. The outer ring rotation had opposite effect on the heat dissipation of raceway contact zone and pocket. Originality/value: The air phase flow field characteristics and the heat transfer performance of CRDRB were revealed and analyzed from the mechanism. An area quantification method was presented as an auxiliary mean of the thermal analysis to evaluate the heat transfer performance of bearing.