Structural design and performance analysis of external gear pump for high viscosity polymer pumping.

High-viscosity gear pumps are key equipment for transporting highly viscous polymer media, and their performance is significantly influenced by the coupling effect of medium viscosity and operational parameters. To address the issues of low pumping efficiency and insufficient equipment stability in the preparation process of aerospace composite materials, this study analyzes the fluid pumping characteristics of composites and the gear pump structure under high-viscosity conditions. A universal high-viscosity external gear pump suitable for GNP2200 aerospace composite preparation was designed, with design calculations performed on the core structure to determine key parameters. Experimental tests were conducted to evaluate the pump's power under varying rotational speeds and medium viscosities. Theoretical calculations and simulation comparisons of the rotational speed were carried out across three viscosity ranges. In addition, volumetric efficiency, energy efficiency, and overall efficiency were computed based on actual working conditions, and the relationship between the dynamic viscosity of the medium and efficiency was analyzed via simulation to comprehensively evaluate the pump's performance. The results indicate that the pumping capacity is closely related to medium viscosity, and the consistency between simulation and theoretical results validates the rationality of the structural design. When the dynamic viscosity is below 5000 cP, the pump achieves a maximum no-load efficiency of 98.5% and a minimum of 87.0%. Maintaining the speed within the range of 65-90 r/min leads to higher pumping efficiency, extended service life, and improved operational performance. This study provides theoretical and practical insights for the optimized design of high-viscosity gear pumps.