Research on Improving the Efficiency of Centrifugal Pump Using the Different Vane Surfaces of Bearings

With the use of the stepped surface of the friction pairs of the stepped bearings (SB) in the high-speed centrifugal pumps, its liquid film thickness is suddenly changed and it was discontinuously distributed in the direction of motion of pump. To ensure the continuity of the liquid film thickness and enhance the lubrication efficiency of the pump, based on the lubrication model of the SB, two other structures of the inclined surfaces [inclined bearings (IB)] and curved surfaces [curved bearings (CB)] used to replace stepped surfaces of the SB are investigated, respectively. Under the same conditions of the minimum thickness of the liquid film and initial dimensions of the sliding friction pairs, the influence of both the thickness ratio (α) of the liquid film and dimension ratio (β) in the direction of motion of SB, IB, and CB on the bearing capacity and friction coefficient of the liquid film are simulated and analyzed, respectively. Based on the optimal ratios {α and β} of SB, IB, and CB in improving bearing capacity and minimizing friction, the lubrication efficiency between SB, IB, and CB is then simulated and compared. The results indicate that the maximum bearing capacity of the CB is obviously enhanced by 11.1% and 39.7%, whereas the minimum friction coefficient is also remarkably decreased by 15.8% and 36.9% compared to the IB and SB, respectively. Besides, the maximum liquid film pressure of the CB is also higher than that of the IB and SB by 5.5% and 13.9%, respectively. Therefore, the use of the curved surface of the CB can further enhance the lubrication efficiency and reduce the friction of the liquid film in the high-speed centrifugal pumps.