An improved nonlinear dynamic model of high speed ball bearings with elastohydrodynamic lubrication (EHL) is adopted to predict the movements of balls and power loss of ball bearings for defining the boundary conditions of computational fluid dynamics (CFD) model. Then, this method of combining nonlinear dynamic and CFD models is are validated through the experimental verification. Subsequently, oil-air flow and temperature distribution inside the bearing chamber are studied at low and high speeds, and light and heavy loads. The effect of nozzle's position on the formation of oil film and heat dissipation is revealed under combined loads. The research results provide a theoretical basis for engineering application of high speed rolling bearings.

To achieve effective cooling for high speed ball bearings, an investigation on the effect of bearing structure on oil-air flow and temperature inside bearing chamber is necessary. However, accurately defining boundary conditions of CFD model for high speed ball bearings has not been addressed completely. Adopting an improved dynamic model of bearings to calculate movements of balls and power loss to set the movement boundary and heat source of CFD model at high-low speeds and light-heavy loads. Then, rotational speed of cage and temperature of outer ring at various loads are tested to validate this proposed method. At high speeds, enlarging sealing degree of outlet not only reduces the temperature rise of bearings and improves the uniformity of temperature distribution, but also promotes the formation of oil-film on balls’ surfaces without increasing power loss. Yet it can reduce the temperature rise but can’t markedly improve the formation of oil-film at low and ultra-high speeds. Moreover, half birfield cage facing nozzle plays an important role in improving oil volume fraction inside the bearing cavity to reduce the temperature rise of bearings, and the next is birfield cage, they are again corrugated cage and half birfield cage back towards nozzle. These research results provide theoretical guidance for the improvement of bearing structure.