高速强制连续约束型航空离合器接触特性及疲劳寿命分析

【作者】 杨兵；

【导师】 严宏志；

【作者基本信息】 中南大学 ， 机械设计及理论， 2011， 硕士

【摘要】 强制连续约束型离合器(PCE型离合器)广泛用于航空工业,是直升机传动系统中的重要装置之一,是保证发动机与主减速系统按要求及时正确结合和脱开的关键部件。离合器的楔块极易磨损和局部剥落,楔块的疲劳破坏严重影响着直升机的安全。本文根据PCE型离合器的工作特点,以设计出高承载力和长寿命的离合器为目的,对离合器接触力学特性和疲劳寿命进行了研究,具体内容如下：PCE型离合器接触特性分析。采用有限元和动力学分析方法对离合器进行了不同摩擦和不同加速条件下的接触力学性能分析,得到了楔合过程的楔块与内、外环的接触应力以及接触力变化规律,为疲劳寿命分析打下了基础。PCE型离合器疲劳寿命分析。介绍了局部应力应变法理论,对适用于离合器的疲劳寿命预测的应变寿命模型做了详细分析,利用修正的通用斜率法分别采用解析法和疲劳分析软件MSC.Fatigue对离合器疲劳寿命进行了计算,结果表明设计出来的PCE型离合器的疲劳寿命满足设计要求。PCE型离合器性能验证试验。设计出一套离合器性能测试装置对离合器进行了性能和疲劳试验,试验验证了离合器有限元、动力学和疲劳寿命分析模型的正确性。根据用户反馈结果,研制的PCE型离合器的各项指标参数均达到了产品研发设计书中提出来的要求,应用效果好。更多还原

【Abstract】 The PCE (positive continuous engagement) type of clutch is an important component in the transmission system of helicopter. It’s the key device between the engine and main gearbox that ensure the engage and disengage function in requirement betimes. The sprag of the clutch is easily wearing and locally spalling, and the fatigue failure of the sprag seriously affect the safety of the helicopter. Therefore, according to the working characteristics of PCE type of clutch, taking design a bearing capability and long life clutch as the goal, this paper carried out research on the mechanical characteristic and the fatigue life of PCE type of clutch. The concrete contents are as follows.Study on the contact mechanical properties of the clutch. Both finite element analysis and dynamics method were conducted to investigate the mechanical characteristics of clutch under different conditions of friction and accelerated time. The distribution curves of distribution contact intensity and steady engagement force between wedges and inner-outer races were analyzed.Study on the fatigue life of the clutch. Through introducing the theory of the local stress-strain method, it indicated that the Modified universal slopes method is fit to forecast the fatigue life of clutch. The fatigue life of clutch was analyzed in MSC. Fatigue soft and modified universal slopes method formula, and the fatigue life of the clutch was meet the design requirements form results.Experiment study on the performance verification of the clutch. We designed an equipment to get the test data of performance and fatigue, the results indicated that the model of finite element、dynamics and fatigue life were suitable. The parameters of the clutch reached the design requirements which proposed in the design books.更多还原