【作者】 谢罗福；

【导师】 杨曙东；

【作者基本信息】 华中科技大学 ， 机械电子工程， 2009， 硕士

【摘要】 翻车机用于铁路车辆的翻卸工作,在我国煤炭、港口货物卸运系统中有着重要地位。翻车机工作时发生掉道事故导致巨大的经济损失甚至人身伤亡,消除翻车机掉道具有十分重要的意义。本文对翻车机液压系统进行了改进以提高翻车机工作可靠性,并设计了一套螺旋机构安装于翻车机大梁,利用其自锁特性从根本上消除翻车机掉道的风险。本文在对翻车机液压系统深入分析基础上,确定了翻车机掉道的根本原因是压车缸在工作过程中回缩的行程超过了车轮轮辕台阶的高度。通过对翻车机液压系统进行改进,提高翻车机液压系统工作可靠性。针对翻车机掉道的风险,设计出一套防掉道机构和相应的液压控制回路。结合翻车机现有结构空间布局,对于防掉道机构的关键部件螺旋副进行了参数设计计算。运用FMECA对翻车机防掉道系统进行分析,确定系统运行过程中可能发生的各种故障模式,以及每一故障模式的原因和影响。找出系统潜在的薄弱环节是支承螺杆和螺旋套,并通过设计优化提高他们的可靠性。液压泵和液压马达失效也是危害度最高的故障模式,液压系统失效的共因是系统污染,因此对液压系统维护工作尤其重要。采用有限元的方法对螺旋副进行强度分析,研究螺旋副承受轴向载荷时的应力和应变分布规律、应力集中情况。通过对螺母外圈尺寸和螺旋副的啮合圈数取不同数值进行分析比较,优化了螺旋副结构参数。更多还原

【Abstract】 Car dumper is widely used to unload bulk materials from trains, leading a significant role on the national transportation system. Derailment accidents while car dumper overturning cargo results in heavy economic damage even person casualty. Thus eliminating car dumper derailment accident is very necessary. Gaining experience from related anti-derailment methods and combining spot investigation, a set of screw pair equipment is designed. The characteristic of screw pair self-lock is applied to eliminate the risk of car dumper derailment.Based on the analysis of hydraulic system of car dumper, the ultimate cause for car dumper derailment is traced that cargo-pressing hydraulic cylinder recession distance exceeds the step height of cartwheel. Hydraulic system is reconstructed to make car dumper work more reliably and reasonably.A set of anti-derailment equipment is designed to eliminate the risk of car dumper derailment. Screw pair is the key component in the set of anti-derailment equipment. By investigating installment space and requirement of working parameter of the car dumper, preliminary parameters for screw pair come out, with checking calculation by the method of material mechanics. The dissertation also discussed the principle of adding hydraulic circuit and completed the selection of related hydraulic components.FMECA is applied to analyze the reliability of anti-derailment system of the car dumper. Various potential failure modes, plus causes and effects of each failure modes, are determined. The weak link of the system is supporting screw rod and nut suit, which reliability should be improved by optimized design. Failure from hydraulic pump and motor were also ascertained as the most critical failure modes. According FMECA analysis, the common causes of hydraulic system components are hydraulic contaminations, which require paying special attentions to hydraulic system maintenances.Finite element method is applied to analyze the screw pair intensity, research on the distribution regularity of stress and strain and stress concentration when imposing axial load on the screw rod. By analyzing and comparing calculation result from defining series of outer diameter of screw nut and series of meshing cycle numbers of screw pair, parameters of screw pair are optimized.更多还原