Experimental research of the valve plate pair pressure in an axial piston pump

To obtain the real pressure distribution of the valve plate pair, a novel experimental system with 18 pressure measurement points is developed. The measurement points are strategically positioned based on numerical results. The pressure measurement layout includes 9 points each in high- and low-pressure areas, with focused attention on transition areas, grooves and inner/outer sealing bands. The feasibility of the experimental method is also analyzed. The comprehensive pressure measurements are conducted under various rotational speeds and load conditions. Based on the acquired data, the pressure distribution and time–frequency characteristics in four grooves are analyzed. The results indicate that the proposed experimental method is feasible. Alternating high pressures are observed in the grooves. Pressure overshoots occur in the high-pressure groove near the top dead center. In addition, multiple pressure peaks are detected in the groove due to pressure shocks. These findings contribute to a deeper understanding of the pressure behaviours of the oil film in the valve plate pair.