Cam Ring Curve Optimization for Radial Hydraulic Motor Based on Seagull Algorithm

With the accelerated adjustment of the global energy structure, the intensity of strategic mineral resource development continues to rise. The growing demand for construction machinery and equipment has led to increased use of radial piston hydraulic motors, known for their low-speed and high-torque characteristics, in heavy-duty mining machinery and equipment. To address the issues of significant contact stress, noticeable output pulsation, and considerable flexible shock in the stator curve design of a radial piston hydraulic motor, this paper proposes a multi-step composite curve optimization design method based on the Seagull Optimization Algorithm (SOA). This method integrates the concepts of “stepped” and “trapezoidal” acceleration curve design, utilizing the SOA algorithm to tackle these challenges. The SOA algorithm is more adaptive than the genetic algorithm (GA) and the particle swarm optimization (PSO) algorithm, maintaining population diversity even in the later stages of iteration. This effectively overcomes the limitations of PSO and GA in multi-peak problems. By establishing a stator curve optimization model aimed at minimizing contact stress through theoretical modeling and dynamics analysis, and combining the global search and local development capabilities of SOA, we achieve multi-constraint optimization on key parameters such as the amplitude-angle ratio in the acceleration zone and the amplitude-angle in the zero-speed zone. This results in a composite stator curve with no shock, low pulsation, and low stress. The effectiveness of this method was validated through bench tests, which showed that the maximum contact stress of the optimized multistep composite curve is reduced by 5.4% and 18.3% compared to the conventional equal acceleration curve and trapezoidal curve, respectively. Additionally, the speed pulsation rate decreases by 10.81% and 25.73% under 20 MPa and 30 MPa conditions, respectively, with no sudden change in reaction force and a reduction in pulsation shock during operation.