安装误差对行星齿轮传动系统传动误差的影响

建立了2K-H人字齿行星齿轮传动系统平移-扭转耦合非线性动力学模型,模型中考虑各构件的支撑刚度,事变啮合刚度和安装误差激励等影响因素。利用当量啮合误差定义,推导了各构件的安装误差在啮合线变长方向的当量啮合误差;分析计算了各构件间的相对位移,根据牛顿第二定律推导系统运动微分方程,采用傅里叶级数法求解系统动力学方程,获得系统的传动误差,分析了安装误差对系统传动误差的影响。     

多间隙弯扭耦合齿轮非线性振动的分岔特性研究

采用集中质量法,建立了齿轮-转子-轴承系统的四自由度的弯扭耦合的非线性振动模型,模型考虑了齿轮副间的时变啮合刚度、齿侧间隙、支承间隙以及综合传递误差等非线性因素;推导出系统的量纲一振动微分方程,采用数值积分方法研究多间隙弯扭耦合齿轮传动的运动随转速、齿侧间隙、支承间隙以及阻尼等参数的分岔特性,同时结合Poincaré截面图,全面系统的分析了转速、啮合阻尼、齿侧间隙以及支承间隙等参数对系统分岔特性的影响。结果发现,在一定的齿侧间隙和啮合阻尼下,随着转速的逐渐增加,系统进入混沌的途径包括激变和拟周期分岔,且随着阻尼系数的增加,系统的分岔和混沌运动被抑制,表现为其混沌区域宽度逐渐降低;在一定的转速和啮合阻尼下,而随着齿侧间隙的逐渐增加,系统会从通过激变进入混沌的途径转变成由倍周期分岔途径进入到混沌,且系统在不同的啮合阻尼下最终锁相为混沌、周期四、周期二和周期一运动;在满足一定的转速和啮合阻尼条件下,随着齿侧间隙的增加,系统可通过倍周期分岔进入并锁定为Naimark-sacker分岔。在满足一定的转速、啮合阻尼和齿侧间隙的条件下,随着支承间隙的增加,系统运动进入狭窄的周期五窗口后锁相为周期一运动,且从系统的控制方程和数值解可以发现支承间隙对系统的运动的影响较弱。     

基于弹流润滑及时变载荷分配模型的直齿轮效率研究

结合弹流摩擦系数模型及直齿轮的啮合特性,推导直齿轮齿面载荷的分布规律;结合啮合过程中齿面载荷、齿面摩擦力的时变性、单双齿啮合特性,对一个啮合周期内齿轮副的输入输出功耗进行积分,获得同时考虑弹流效应及时变载荷分配模型的直齿轮啮合效率计算公式;建立基于Matlab的直齿轮效率数值分析模型,将仿真结果、ISO/TR 14179-1、ISO/TR 14179-2效率计算结果、试验数据进行对比分析。结果表明:基于弹流润滑及时变载荷分配模型的直齿轮效率计算方法与试验数据具有很好的一致性,且对效率预测的准确性好于标准ISO/TR14179-1、ISO/TR 14179-2。     

Vibration transmissibility characteristics of smart spring vibration isolation system

The objective of this work was to study the vibration transmissibility characteristics of the undamped and damped smart spring systems. The frequency response characteristics of them were analyzed by using the equivalent linearization technique, and the possible types of the system motion were distinguished by using the starting and ending frequencies. The influences of system parameters on the vibration transmissibility characteristics were discussed. The following conclusions may be drawn from the analysis results. The undamped smart spring system may simultaneously have one starting frequency and one ending frequency or only have one starting frequency, and the damped system may simultaneously have two starting frequencies and one ending frequency. There is an optimal control parameter to make the peak value of the vibration transmissibility curve of the system be minimum. When the mass ratio is far away from the stiffness ratio, the vibration transmissibility is small. The effect of the damping ratio on the system vibration transmissibility is significant while the control parameter is less than its optimal value. But the influence of the relative damping ratio on the vibration transmissibility is small.