Energy analysis of the articulated mining car’s electrohydraulic closed hydraulic direct drive folding waist follow-up steering system

Against the backdrop of increasing global environmental pollution and energy crisis, enhancing the efficiency of equipment components and systems has become a consensus in the industry. With their exceptional turning radius and adaptability to narrow roadways, articulated mining vehicles have garnered significant attention in the mining sector. However, due to the limitations of their structural and pipeline design, traditional valve-controlled hydraulic articulated steering systems exhibit significant pressure losses, high return oil backpressure, and relatively low energy efficiency. Therefore, the adoption of an electro-hydraulic closed-loop hydraulic direct-drive articulated steering system configuration is proposed. Based on the elaboration of its working principle, a multi-degree-of-freedom dynamic model encompassing the movement of the front and rear vehicle bodies, wheel rotation, and electro-hydraulic direct-drive steering is established to theoretically analyze the energy consumption during the articulated steering process. Utilizing the existing WXJ15 heavy-duty articulated support handling vehicle for mining experiments, a comparative analysis of the energy consumption of the electro-hydraulic closed-loop hydraulic direct-drive and traditional valve-controlled articulated steering systems under given working conditions was conducted. The results indicate that, under the same cyclic working conditions, the energy consumed by the electro-hydraulic closed-loop direct-drive steering configuration is only 40% of that of the traditional valve-controlled full hydraulic system. Further analysis reveals that the primary source of energy loss in the traditional valve-controlled hydraulic steering system is throttling loss from the hydraulic steering valve, accounting for up to 61.5% of the total loss. In contrast, the main source of energy loss in the electro-hydraulic closed-loop hydraulic direct-drive articulated system is the energy loss of the main pump, accounting for approximately 96.8% of the total loss. Compared to the traditional valve-controlled hydraulic steering system, the electro-hydraulic closed-loop hydraulic direct-drive steering system achieves a 15.4% reduction in electrical energy consumption, a 27.5% increase in total steering work accomplished under the same electrical energy, and a 43.5% improvement in steering work per unit of electrical energy.