Optimization Design of Nonpulsating, Equal Contact Stress Guide Curves for Internal Curve Radial Piston Motors

To address the issues of short lifespan and high pulsation rates in existing radial piston hydraulic motors, this study focused on the design and optimization of the guide curve based on contact stress analysis. Initially, a thorough mechanical analysis and mathematical modeling of the piston rollers were conducted, taking into account friction forces. Using a six-action, eight-piston motor as a case study, the movement patterns of the pistons were extensively analyzed, and the corresponding torque was calculated. An extended acceleration zone approach was employed to develop a mathematical model of the guide curve, aimed at achieving constant contact stress without pulsation. Finally, the nondominated sorting genetic algorithm (NSGA-II) was utilized to optimize the lifespan of the guide, resulting in a guide curve that ensures a longer operational lifespan and low pulsation rate. This design method for the guide curve offers a critical reference for optimizing the design of internal curve radial piston motors, which require stringent control over both lifespan and pulsation rates.