Validation and application of a numerical approach for the estimation of drag and churning losses in high speed roller bearings

Highlights: • A new method to estimate the hydraulic losses in roller bearings is proposed. • The method is validated by comparing with three empirical models. • The method is employed to analyze a special counter-rotating roller bearing. • The natural configuration shows advantage over the inverted one. -- Abstract: A numerical-based model is proposed to estimate drag and churning losses in high speed roller bearings, which is caused by the rotation and translation of the rollers in the fluid environment inside the bearing. Three existing models for the total hydraulic loss prediction are used to validate the numerical approach, including the SKF model, the Palmgren model, and the Parker model. After that, the validated model is employed to analyze drag and churning losses of counter-rotating roller bearings, having obvious advantage over the other three models. Results show that the numerical model is close to the Parker model and partly similar with the SKF model if the supply of the lubricant oil is sufficient. And the estimated result by the Palmgren model is always the lowest. For the counter-rotating roller bearing, it is demonstrated that the drag and churning losses are rather serious due to its two rings rotating together, and they are related to the bearing supporting design. This is of importance for the intershaft supporting application in turbine engine where precise lubricating system design is a big challenge.