多片离合器早期故障生成机理及振动诊断方法

Initial Malfunction Generating Mechanism and Vibration Diagnosis Method on Multi-plate Clutch

利用热弹性不稳定理论,建立离合器摩擦副热弹耦合模型,获得了由热点集聚导致摩擦片发生局部变形的基本过程。依据该过程,提出以观测摩擦片局部变形来反映离合器早期故障的思路。基于该思路,建立多片离合器动力学仿真模型,获得了当摩擦副上存在微小变形时系统的动力学特性。根据该特性的振动学特征,并利用传动系统高频段干扰噪声较轻的特点,通过换挡时刻前后高频段频谱的差异性分析,提出一种基于振动信号分析的多片离合器早期故障诊断新方法。试验结果表明,该方法能够提取出由摩擦副上局部变形产生的冲击振动,可望用于多片离合器早期故障诊断的工程实践中。

The thermoelastic coupling model of clutch friction pair is built up with thermoelastic instability theory, through that is acquired the basic process of friction disk warping deformation caused by hot agglomeration. Based on the process, the idea is put forward that the initial malfunction of clutch could be analyzed by observing the local deformation generated by hot spots. From the point of that view, the dynamic simulation model on multi-plate clutch is established, and the system dynamic characteristic of micro deformation existing on the friction pair is obtained. According to the vibration property of the characteristics and with the transmission system peculiarity that the magnitude of noise is lighter on high frequency＇, through the difference analysis of frequency spectrum before and after the shifting time, a new diagnosis method on multi-plate clutch initial malfunction based on vibration signal analysis is put forward. Experimental results show that, the impact vibration generated by the tiny deformation on the friction pairs can be extracted with the method, which is expected to be used in the engineering practice on initial fault diagnosis for multi-plate clutch.