【摘要】 考虑齿轮的时变啮合刚度、非线性侧隙等因素,根据3自由度齿轮集中质量模型,建立了采煤机牵引部的动力学整体模型,研究变速重载工况下系统的振动响应,获得了牵引部各位置的动态接触应力。考虑随机运动参数、结构参数与材料参数系统等的影响,基于鞍点逼近方法获得了系统功能函数的概率密度函数与概率分布函数,基于顺序统计量理论研究了载荷多次作用下牵引部传动系统的动态可靠性评价问题,计算结果表明:随着系统运转时间的增加,传动系统中齿轮接触应力分布均值增大且标准差减小;动态运转过程中,牵引系统首次运转是较为安全的,系统前期可靠性降低速度较快,后期可靠性递减速度较缓慢。更多还原

【Abstract】 Considering the time-varying mesh stiffness and nonlinear backlash of gear,the lump mass method of three degree-of-freedom gear was adopted to establish overall model,including the traction unit and walking unit of shearer.The vibration responses and contact stress of traction unit were investigated in the conditions of variable speed and heavy load. The kinematic parameters,structure parameters and material parameters were taken into consideration as random factors in the tractive transmission system. The probability density function and cumulative distribution function were obtained in accordance with saddlepoint approximation method for the system’s performance function. Based on order statistic theory,dynamic reliability was calculated to evaluate the tractive transmission system under repeated load. Research results show that the average dynamic contact stress increases and its standard deviation decreases with the increase of operation time. In the process of dynamic motion,the tractive transmission system is comparatively secured at the first time. The system reliability decreases rapidly in the earlier stage and declines tardily in the later stage.更多还原