Modeling and Analysis of Hydrostatic Pockets in the Cylinder Block–Valve Plate Lubricating Interface of a Floating Piston Pump
DOI:
https://doi.org/10.13052/ijfp1439-9776.2715Keywords:
Contact, cylinder block, efficiency, hydrostatic, lubrication, piston-type pump, simulation, valve plateAbstract
Piston-type positive displacement machines are used across diverse applications and operating conditions, posing a critical design challenge to minimize solid-body contact while maintaining high efficiency. This study investigates the potential of hydrostatic pockets between the cylinder block and valve plate to provide dynamically and passively controlled pressure forces, mitigating contact issues at low speeds without excessive losses at high speeds.
Simulations of a baseline pump design revealed persistent solid-body contact under low-speed and high-pressure conditions, indicating the need for enhanced lubrication strategies. Retaining the baseline design, the study examined multiple hydrostatic pocket configurations through simulation, varying their location, quantity, and size. Furthermore, this study also investigates the size of the grooves, which act as constant-area orifices connecting the hydrostatic pockets and displacement chambers. Although the primary focus is on low-speed high-pressure and high-speed high-pressure scenarios, additional operating points at low-speed low-pressure, high-speed low-pressure, and medium-speed medium-pressure are also considered.
The effectiveness of each design is evaluated on the basis of film thickness, contact pressure, leakage, torque, and viscous losses under key operating conditions. The simulation results are then compared with the experimental findings reported in prior literature, and they suggest that placing the hydrostatic pockets farther from the displacement chambers leads to greater improvements, particularly in reducing leakage, minimizing viscous losses, and avoiding metal-to-metal contact. This paper seeks to deliver a better understanding of the hydrostatic pockets and the corresponding groove orifices, offering design guidance for optimizing the lubrication management for future piston-type positive displacement machines and informing strategies for improved efficiency and longevity in demanding applications.
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