This paper presents a coupled numerical-analytical framework for investigating the influence of the oil film dynamics on the vibration characteristics of the hydraulic piston pump. A finite difference solver is developed to compute the hydrodynamic pressure distribution in the distribution plate under realistic operating conditions, from which equivalent stiffness and damping coefficients are extracted using analytical squeeze-film relations and integrated into a single-degree-of-freedom vibration model. For the baseline case (\( \mu = 7.7 \times 10^{-4} \, \text{Pa·s}, \, \omega = 4000 \, \text{rpm}, \, p_p = 21.5 \, \text{MPa}, \, \gamma = 14^\circ \)), the simulation yields a mean pressu... More >