Study on hydraulic dynamic external characteristics of mechatronic electro-hydraulic coupler

The Mechatronic Electro-Hydraulic Coupler (MEHC) is a power transmission device that facilitates the coupling and conversion of electrical energy, mechanical energy, and hydraulic energy. The MEHC effectively address issues related to insufficient motor power and low energy utilization efficiency in electric vehicles under overload conditions. Given that hydraulic power is a critical energy source for the MEHC, it is essential to focus on the hydraulic power system to improve efficiency. This study provides a detailed analysis and discussion of wear and leakage in the hydraulic system, focusing on the external characteristics of the hydraulic power system, which describe the system’s performance under the influence of external factors. Equations for the mechanical efficiency, volumetric efficiency, and total efficiency of the hydraulic power system are derived. Mechanical efficiency is then calculated. The instantaneous flow and instantaneous leakage of the hydraulic power system were simulated based on Fluent fluid simulation software, and the volumetric efficiency was calculated based on the derived equation. From the the volumetric and mechanical efficiencies, the total efficiency of the hydraulic system is obtained, and the MEHC extra-hydraulic characteristics are finally deduced. The results provide a basis for the selecting control strategies to regulate the electro-hydraulic ratio and optimize the efficiency and performance of the MEHC.