点蚀作用下变位行星齿轮系统动态特性研究

Research on the Dynamical Characteristics of Planetary System with Gear Shift Under Gear Pitting

以某行星齿轮系统为研究对象,考虑实际工况下的齿轮安装变位特征,建立点蚀作用下故障齿面的啮合刚度有限元分析模型。分析不同点蚀位置、点蚀尺寸对行星变位齿轮啮合刚度影响,并以时变啮合刚度和传动误差作为综合输入激励,对行星齿轮系统进行动力学响应求解,研究点蚀特征对变位行星齿轮系统振动特性的影响。研究结果表明:点蚀显著降低啮合刚度,在啮合周期内,点蚀在齿根位置的啮合刚度变化最显著,且点蚀坑尺寸越大,啮合刚度减小越多;各点蚀区尺寸下的平均啮合刚度,都随正变位增大而减小,负变位增大而增大;点蚀对系统振动响应的影响主要表现为频谱上的故障频率及其倍频成分,且故障频率及其倍频的幅值随点蚀坑尺寸增加而增大,随正变位增大而增大,负变位增大而减小。此外,随着点蚀坑尺寸增大,Kurtosis值和RMS值均增大,但Kurtosis值对点蚀故障更灵敏。

In this research, a planetary gear system is employed as the research objective. Considering gear installation shift in the actual conditions of the planetary system, and a mesh stiffness finite element analysis model is established with tooth surface pittingfault. The influence of different pitting locations and the change of pitting sizes on the mesh stiffness under gear shift are analyzed. Then, the dynamic response of the system is solved by the mesh stiffness and error excitation, and the effect of pitting on the system vibration characteristics is analyzed. The results show that the pitting fault can significantly reduce the mesh stiffness. In a mesh period, the effect is the most significant when the pitting is on the tooth root position, and pitting size is greater, the mesh stiffness decreases more. The average mesh stiffness under different pitting sizes decrease with the increase of the positive modification coefficient, increase with the increase of the negative modification coefftcient. Pitting fauh also has obviously influence on the system vibration response. Pitting fault frequency and its frequencies multiplication are mainly characteristic frequencies in the spectrum, and the amplitudes of the fault frequency and their frequenciesmultiplication will increase with the increase of the pitting size and the positive modification coefficient, and will decrease with the increase of the negative modification coefftcient. In addition, as the pitting size increase, the value of Kurtosis and RMS become larger, but the Kurtosis value is more sensitive to the fault response.