Session: Pumps 1

Paper Number: 111370

111370 - The Transition of Wear and Leakage Characteristics of the Cylinder Block/Valve Plate Interface in a Wide Range of Operating Conditions 

        In order to take full advantage of the servo motor-driven pump, it usually demands that the axial piston pumps work in an extremely wide range of operating conditions, which inevitably leads to a great change in performance due to the transition of frictional behavior. While the Stribeck curve is beneficial to reveal the influence of operating conditions on lubrication performance which can be used to determine the optimum operating range to improve the reliability and efficiency of axial piston pumps.  As the critical friction interface of axial piston pumps, the cylinder block/valve plate interface represents an important source of power losses due to friction and leakage. However, the Stribeck curve for the cylinder block/valve plate interface is usually conceptual without real data. It is a great challenge to numerically describe the entire spectrum of lubrication status transiting from the boundary and mixed lubrication to full-film hydrodynamic lubrication. In this paper, a unified mixed elastohydrodynamic lubrication (mixed-EHL) model for valve plate/cylinder block interface is established to investigate friction behavior in the form of Stribeck curves. The influence matrix (IM) method is used to obtain the elastic deformation of cylinder block and valve plate offline. And the average flow Reynolds equation together with an asperity micro-contact model was employed to calculate the pressure distribution and interfacial friction in mixed lubrication regime. Based on the numerical study, the fluid-structure interaction mechanism under specific operating conditions is analyzed, including the lubrication status distribution, elastic deformation of solid parts, and cylinder block tilt attitude. Furthermore, a calculated three-dimensional Stribeck surface for cylinder block/valve plate interface is constructed to illustrate the frictional behavior in a wide range of operating conditions. At last, the optimum speed range under different operating pressures is obtained. The calculated Stribeck curves can be used as a guide tool for the operating condition optimization of axial piston pumps.

        Keywords: cylinder block/valve plate interface, axial piston pumps, Stribeck Curves, mixed-EHL model, fluid-structure interaction

Presenting Author: Xuguang Li State Key Laboratory of Fluid Power and Mechatronic Systems

Presenting Author Biography: Xuguang Li received his B.S. degree in machine design & manufacturing & automation from Central South University, Changsha, China, in 2021. He is currently working toward the Ph.D. degree in the College of Mechanical Engineering, Zhejiang University, Hangzhou, China. His research interests focus on the design and optimization of high-speed hydraulic pumps and motors.