Analysis and validation of the bending moment transmission in four-point support transmission chain for wind turbines

TIAN Yonglin; ZHENG Guolong; PENG Chao

doi:10.16578/j.issn.1004.2539.2026.05.014

Abstract：[Objective]Aiming at the problem that the four-point support transmission chain of wind turbines is designed as pure torsion while ignoring bending moment transmission,the load-bearing mechanism of hydraulic elastic supports and the law of additional bending moment transmission caused by system micro-deformation were thoroughly explored to provide a reference for the design optimization of transmission components.[Methods]Firstly,the stiffness composition and bending moment transmission mechanism of hydraulic elastic supports were analyzed,and the superposition characteristics of bending-torsion coupling were clarified to lay a foundation for modeling.Secondly,a transmission dynamic model was established using SIMPACK software,and a calculation method for equivalent torsional stiffness was proposed to achieve decoupling of vertical and torsional stiffness,ensuring model authenticity.Thirdly,bending-torsion coupling tests were carried out on a 6-degree-of-freedom test bench,and load data at the hub center and gearbox input end were obtained by applying loads under different working conditions using the control variable method.Finally,the simulation and test results were compared,the causes of deviations were analyzed and the model was corrected to verify the reliability of the method.[Results]The results show that the simulation and test results are highly consistent in both the trend and quantification of bending moment transmission.The maximum deviation of the bending moment at the gearbox input end is no more than 7.71%.Part of the hub center bending moment is transmitted to the gearbox,with the transmission ratio less than 3%in the heavy load range and less than 4%in the light load range.The results have practical guiding significance for the design of relevant drivetrain components.