【摘要】 旋转机械中齿轮冲击类故障诊断的主要依据之一就是信号中存在以啮合频率为中心频率、以故障齿轮转频为间隔频率的边频带,但工程实际表明,齿轮发生断齿、严重点蚀等冲击类故障并不一定会出现啮合频率,针对这种现象,从更一般的应用出发,以工程应用为目的,基于机械振动理论研究了单自由度振动系统的一般性的周期性冲击响应信号在时域和频域的特征,结果表明:单次冲击响应时域波形为一周期性衰减振动,振动频率为系统有阻尼固有频率;周期性冲击响应信号时域波形为单次冲击响应时域波形的迭加,频谱图上出现以系统固有频率为中心频率、以冲击频率为间隔频率的边频带;混有简谐信号的周期性冲击响应信号,其频谱图上边频带呈不对称分布。研究结果为工程实际中相应故障的诊断提供了理论依据。更多还原

【Abstract】 The existing of side band where meshing frequency is the central frequency and the operating frequency of faulty gear is modulating frequency is one of diagnostic bases of gear faults in rotating machines.However,in practice it is found occasionally that the meshing frequency of gear pair is not obvious when the tooth of gear is broken or pitting is appearing.According to the phenomenon,for more general application,based on mechanical vibration theory,the time and frequency characteristics of a single degree of freedom system is investigated when it is met with single impulse excitation,periodic impulse excitation and mixed excitation consistingof simple harmonic excitation and periodic impulse one.The results show the time wave of single impulse response of the system is periodic damped vibration which vibration frequency is damped natural frequency of the system;the time wave is the overlap of one of single impulse response in different time and the side band is obvious where the central frequency is the natural frequency of the system and it is evenly spaced with impulse frequency;the side band is asymmetric in both sides of central frequency when mixed excitation is imposed on the system.The results present reference for the diagnosis of this kind fault.更多还原