Thermal characteristics of the valve plate in an axial piston pump: Experiment and simulation

Temperature plays a critical role in the heat transfer and thermal-fluid behavior in valve plate pairs. To investigate the temperature distribution and thermal characteristics of the valve plate, a coupled heat transfer model and an experimental system with 28 testing points are developed. The simulated and experimental data exhibit good agreement, with an average temperature error of 10.6% at the four grooves under different load pressures. The temperature distribution and thermal characteristics of the valve plate are studied, particularly in four grooves. The influences of pressure and rotational speed on the temperature field are quantified using an incremental dimensionless ratio. The results reveal a distinct temperature gradient across the valve plate, with localized high temperatures occurring at four grooves. Cylinder tilting induced by high rotational speed leads to an elevated temperature around the bottom dead center area. The number of temperature peaks increases at 2850 r/min. The effect of rotational speed on the valve plate temperature is more significant than that of load pressure. The effect of jet flow intensifies shear stress and viscous dissipation within the grooves. The low pressure in grooves may promote cavitation that would generate localized high temperature. These findings provide fundamental insights into the heat generation, heat transfer mechanisms, and thermal-fluid coupling behavior of valve plates in hydraulic machinery.