Efficiency of electro-hydraulic servo steering for heavy construction vehicles

摘要

The traditional efficiency analysis method of hydraulic system generally neglects the influence of mechanical nonlinearity, which causes great difference between theoretical efficiency optimization and actual application. This will reduce the energy-saving effect. In this paper, the electro-hydraulic servo steering system (EHSSS) of heavy vehicles is taken as the research object. Considering both mechanical nonlinearity and hydraulic nonlinearity of the steering system, this paper establishes the efficiency model of the EHSSS. In order to achieve the efficiency analysis of this nonlinear model, an efficiency analysis method in quasi-steady state condition is proposed. The theoretical analysis is consistent with the experimental results in four different single-side loading conditions, so the validity of the model and method is verified. Then, based on the above model and method, the system efficiency spectrums are obtained in different operating conditions. The efficiency of the EHSSS with strong nonlinearity is not only related to the equivalent load but also the steering angle. The results show that the efficiency is the highest in the maximum equivalent load conditions and at left or right end points. In addition, this paper obtains the efficiency curves of steering system in different speeds, hydraulic parameters and structural parameters. The method presented in this paper takes into account the effect of mechanical nonlinearity on the efficiency, which provides theoretical guidance for further efficiency improvement of electro-hydraulic steering system.