In this study, the design, manufacturing, modal analysis and flow performance of hydraulic pumps with elliptical and spur gear profiles are compared experimentally. Firstly, both gear types are modeled in a computer-aided design (CAD) environment and their natural frequencies and mode shapes are analyzed using the finite element method (FEM). As a result of modal analyses performed on four different thermoplastic materials, ABS, PC, PETG and PLA, PLA material is preferred due to its high frequency resistance and production suitability. In line with the selected geometry and material, gear pairs were produced by additive manufacturing (3D printing) method and prototype pumps are assembled. Both pump systems are tested at rotational speeds ranging from 1000 to 3000 rpm to measure volumetric flow performance. Experimental results showed that, at all speeds, the elliptical gear pump delivered a higher and more stable flow rate compared to the spur gear pump. At the highest test speed of 3000 rpm, the elliptical gear pump achieved an average flow rate of 23.6 L/min, whereas the spur gear pump produced only 4.9 L/min. Similarly, at the lowest test speed of 1500 rpm, the elliptical gear pump generated 8.29 L/min, while the spur gear pump delivered 2.05 L/min. These findings indicate that the elliptical gear geometry can improve pump performance by approximately fourfold, offering a compact and highly efficient alternative for hydraulic systems.
Yazar et al. (Sat,) studied this question.