Analysis of flow field characteristics of non-circular gear hydraulic motors under the influence of multiple factors

Abstract

This study conducts an in-depth investigation into the flow field characteristics of non-circular gear hydraulic motors under high-water-based emulsion environments. While non-circular gear hydraulic motors exhibit significant advantages, such as low speed and high torque, the unique properties of high-water-based emulsion result in complex internal flow field behavior, with limited related research available. Therefore, this paper systematically analyzes the flow field characteristics of the hydraulic motor under typical operating conditions using computational fluid dynamics methods. The simulation results indicate that increasing the sun gear speed (100-500 rpm) reduces flow pulsation from 9.63 % to 6.33 % (a decrease of 34.3 %) and suppresses cavitation, although it also reduces the chamber filling flow rate. Increasing the inlet pressure (5-20 MPa) enhances the chamber filling capacity but causes flow pulsation to increase from 8.50 % to 10.82 % (an increase of 27.3 %) and exacerbates cavitation. Increasing emulsion concentration (0-10 %) leads to a decreased instantaneous flow rate and weakens the chamber filling capacity, with flow pulsation reduced from 10.76 % to 8.67 % (a 19.4 % decrease). This change has little impact on pulsation but effectively suppresses cavitation. The findings provide a theoretical foundation and technical support for the structural optimization and performance enhancement of high-water-based non-circular gear hydraulic motors.