Research on the main geometric characteristics of double-action swing scraper pumps

To address the limitations of traditional hydraulic equipment, such as large size and poor sealing performance, this paper proposes a novel double-acting scraper pump characterized by high efficiency, low pulsation, and a compact structure. Firstly, the structure of the pump and the rotor profile are introduced, and a sine rotor profile equation applicable to any number of blades is established. Using a five-leaf rotor as an example, differential geometry derivation reveals that the curvature undergoes periodic sinusoidal changes, confirming the geometric smoothness of the rotor profile. The derived volumetric utilization coefficient equation provides a theoretical basis for rotor optimization. The study further develops an equivalent leakage model and related flow rate formulas. The instantaneous flow curve demonstrates that flow rate variation is periodic and output remains stable. Finally, the system analyzes the coupled motion laws of the scraper’s swing angle, angular velocity, and angular acceleration. Theoretical calculations and ADAMS simulation verification yield corresponding variation curves that show good agreement, with an error margin of less than 5%. The correctness of the theoretical geometric analysis has been confirmed. This provides a theoretical basis for the design of non-pulsating scraper pumps, as well as the development and performance optimization of prototype machines.