Seal reliability analysis and robust optimization for friction pair on port plate and cylinder of hydraulic piston pump with finite probability information

The reliability design of hydraulic piston pumps is critical for ensuring their performance and longevity. However, challenges arise due to limited probability information of uncertain variables and parameters, as well as the multi-state operation of the friction pair on the port plate and cylinder, adding complexity to the design process. To overcome these challenges, we propose a novel multi-state sealing reliability design model that considers both load and motion effects while accounting for finite probability information. This model utilizes a state function to accurately represent the power of the friction pair, enabling a precise and rational assessment of reliability. We present a numerical example to illustrate the application of our proposed method and compare its results with those obtained from the Monte Carlo simulation. The comparison demonstrates the effectiveness of our approach in enhancing the reliability design of hydraulic piston pumps. Additionally, we have implemented a reliability sensitivity analysis by establishing a matrix relation for the differential of the numerical characteristics of the state function to those of the basic random variables, which is meaningful as it allows us to explore how random variables influence the reliability of hydraulic pumps. Building on this, we conduct a reliability-based robustness design, and the optimization results demonstrate that our reliability design significantly enhances the reliability level. This empowers designers and engineers to make informed decisions and optimize the design, resulting in more robust and efficient hydraulic piston pumps.