Study on the Characteristics of Hydraulic Radial Plunger Pump with Power Valve Distribution

High-pressure seawater pumps are essential in underwater systems, yet their broader application is constrained by substantial volume, heavy weight, and limited miniaturization. To overcome these obstacles, this study proposes a novel prototype design that improves system compactness and functionality. A radial plunger pump equipped with a variable valve distribution system is developed. The system integrates two synchronized variable valves to enable bidirectional flow control, thereby replacing conventional one-way valves. A mathematical model is developed, and numerical studies are carried out to evaluate the effects of rotational speed and plunger pair clearance on leakage, output flow performance, and internal system dynamics. Under rated conditions (1000 rpm, 10 MPa) with a 15 μm one-side clearance, the simulated pump shows a displacement of 0. 025 L/min, an output flow of approximately 0. 0247 L/min, a volumetric efficiency of 90.4%, and a flow pulsation of 6.67%. The distribution valve achieves a maximum flow rate of 0.0236 L/min through coordinated valve actions. Experimental validation under no-load and loaded conditions gives an actual flow rate of about 0. 0226 L/min. The proposed system effectively enables bidirectional operation, reduces internal leakage, enhances volumetric efficiency, and significantly improves overall pump performances, confirming its suitability for the application of water hydraulic technology in marine mechatronics, such as Argo float buoyancy actuation system.