某型无人机起落架缓冲器卡滞故障分析

Binding Failure Analysis for an Unmanned Aircraft Landing Gear Shock Absorber

针对某型无人机前起落架在落震试验中出现的缓冲器卡滞故障,以该起落架为研究对象分析其构型,建立了落震动力学模型。采用优化的方法选择最优的缓冲器参数,由于卡滞缘故,仿真结果与试验结果不符,无法满足地面垂向载荷的要求。进而对缓冲器油孔、机轮带转速度和缓冲器支柱安装角度等参数对缓冲器摩擦力以及落震性能的影响进行了研究。研究表明,机轮带转速度和缓冲器支柱安装角度对缓冲器摩擦力的影响很大,卡滞现象是因为起落架刚度不足引起的,调整支柱安装角度可有效减小缓冲器摩擦力,减小地面垂直载荷。

Due to the binding problem which occurs in the drop test of an unmanned aircraft nose landing gear,the drop dynamic model is built based on the structure of the landing gear. The method of optimization was used to find the most appropriate parameters of shock absorber,but the numerical calculation results didn't verified those from drop test because of binding,which cannot settle for the need of vertical force. Furthermore,the influence on shock strut friction force and drop dynamics,which of shock absorber orifice and speed of wheel and angle of shock absorber were studied here. Studies showed that speed of wheel and angle of shock absorber had a great effect on shock strut friction force,and binding failure was coursed by the low stiffness. The method of adjusting angle of shock absorber could decrease friction force and vertical force effectively.