The component of gear vibration signal is very complex,when a localized tooth defect such as a tooth crack is pre- sent,the engagement of the cracked tooth will induce an impulsive change with comparatively low energy...The component of gear vibration signal is very complex,when a localized tooth defect such as a tooth crack is pre- sent,the engagement of the cracked tooth will induce an impulsive change with comparatively low energy to the gear mesh signal and the background noise.This paper presents a new comprehensive demodulation method which combined with amplitude envelop demodulation and phase demodulation to extract gear crack early fault.A mathematical model of gear vibration signal contain crack fault is put forward.Simulation results based on this model show that the new comprehensive demodulation method is more effective in finding fault and judging fault level then conventional single amplitude demodulation at present.展开更多
This paper presents a procedure of sing le gear tooth analysis for early detection and diagnosis of gear faults. The objec tive of this procedure is to develop a method for more sensitive detection of th e incipient ...This paper presents a procedure of sing le gear tooth analysis for early detection and diagnosis of gear faults. The objec tive of this procedure is to develop a method for more sensitive detection of th e incipient faults and locating the faults in the gear. The main idea of the sin gle gear tooth analysis is that the vibration signals collected with a high samp ling rate are divided into a number of segments with the same time interval. The number of signal segments is equal to that of the gear teeth. The analysis of i ndividual segments reveals more sensitively the changes of the vibration signals in both time and frequency domain caused by gear faults. In addition, the locat ion of a failed tooth can be indicated in terms of the position of the segment t hat deviates from the normal segments. An experimental investigation verified th e advantages of the single gear tooth analysis.展开更多
Conventional fault tree and reliability analysis do not reflect the characteristics of basic events as non stationary and ergodic process. To overcome these drawbacks, theory of fuzzy sets is employed to run fault tre...Conventional fault tree and reliability analysis do not reflect the characteristics of basic events as non stationary and ergodic process. To overcome these drawbacks, theory of fuzzy sets is employed to run fault tree analysis(FTA) of roller oscillating tooth gear drive(ROTGD), the relative frequencies of basic events are considered as symmetrical normal fuzzy numbers, from the logical relationship between different events in the fault tree and fuzzy operators AND and OR, fuzzy probability of top event is solved. Finally, an example is given to demonstrate a real ROTGD system.展开更多
齿面点蚀是一种典型的行星齿轮系统故障。为识别点蚀状态,本文开展动力学特性研究并提出了一种新型的评估指标。首先,虑及过渡曲线和齿间结构耦合效应,利用改进Weber法建立了精确的含点蚀故障齿轮副啮合刚度模型,并研究了故障程度对啮...齿面点蚀是一种典型的行星齿轮系统故障。为识别点蚀状态,本文开展动力学特性研究并提出了一种新型的评估指标。首先,虑及过渡曲线和齿间结构耦合效应,利用改进Weber法建立了精确的含点蚀故障齿轮副啮合刚度模型,并研究了故障程度对啮合刚度的影响规律。然后,综合考虑时变啮合刚度、静态传动误差、齿侧间隙和时变振动传递路径等多种因素构建了行星齿轮系统平移-扭转动力学模型,揭示了点蚀程度对系统动态特性的影响规律,并基于振动信号频谱特点提出了边带能量因子(Sideband Energy Factor,SEF)用于损伤评估。最后,利用实验验证了仿真模型的正确性及所提指标的有效性。展开更多
文摘The component of gear vibration signal is very complex,when a localized tooth defect such as a tooth crack is pre- sent,the engagement of the cracked tooth will induce an impulsive change with comparatively low energy to the gear mesh signal and the background noise.This paper presents a new comprehensive demodulation method which combined with amplitude envelop demodulation and phase demodulation to extract gear crack early fault.A mathematical model of gear vibration signal contain crack fault is put forward.Simulation results based on this model show that the new comprehensive demodulation method is more effective in finding fault and judging fault level then conventional single amplitude demodulation at present.
文摘This paper presents a procedure of sing le gear tooth analysis for early detection and diagnosis of gear faults. The objec tive of this procedure is to develop a method for more sensitive detection of th e incipient faults and locating the faults in the gear. The main idea of the sin gle gear tooth analysis is that the vibration signals collected with a high samp ling rate are divided into a number of segments with the same time interval. The number of signal segments is equal to that of the gear teeth. The analysis of i ndividual segments reveals more sensitively the changes of the vibration signals in both time and frequency domain caused by gear faults. In addition, the locat ion of a failed tooth can be indicated in terms of the position of the segment t hat deviates from the normal segments. An experimental investigation verified th e advantages of the single gear tooth analysis.
文摘Conventional fault tree and reliability analysis do not reflect the characteristics of basic events as non stationary and ergodic process. To overcome these drawbacks, theory of fuzzy sets is employed to run fault tree analysis(FTA) of roller oscillating tooth gear drive(ROTGD), the relative frequencies of basic events are considered as symmetrical normal fuzzy numbers, from the logical relationship between different events in the fault tree and fuzzy operators AND and OR, fuzzy probability of top event is solved. Finally, an example is given to demonstrate a real ROTGD system.
文摘齿面点蚀是一种典型的行星齿轮系统故障。为识别点蚀状态,本文开展动力学特性研究并提出了一种新型的评估指标。首先,虑及过渡曲线和齿间结构耦合效应,利用改进Weber法建立了精确的含点蚀故障齿轮副啮合刚度模型,并研究了故障程度对啮合刚度的影响规律。然后,综合考虑时变啮合刚度、静态传动误差、齿侧间隙和时变振动传递路径等多种因素构建了行星齿轮系统平移-扭转动力学模型,揭示了点蚀程度对系统动态特性的影响规律,并基于振动信号频谱特点提出了边带能量因子(Sideband Energy Factor,SEF)用于损伤评估。最后,利用实验验证了仿真模型的正确性及所提指标的有效性。
