滚动轴承故障的时频联合分析和精密诊断研究

滚动轴承的故障需要综合运用多种方法才能进行有效的诊断.本文以型号为B22459-464的轮毂轴承的一个故障为例,运用谱阵和频谱分析的方法直观判别出故障的冲击特征.随后计算出代表故障特征的振动信号的峰值指标、峭度指标、脉冲指标和裕度指标等参数.计算结果表明被测轴承在一定的转速下确实出现冲击的现象.对振动信号用时频分析方法-小波包方法处理,提取出其中的谐振频率成份,运用包络分析的方法对谐振信号进行解调,还原出故障的特征频率约为35.0Hz,与该轴承滚子的特征频率（理论值37.3Hz）接近.拆解表明,正是因为一个滚子的剥落造成了冲击的产生.

Study on time-frequency joint analysis and accurate diagnosis of fault of rolling bearing

Comprehensive methods must be used to diagnose failures of rolling bearing efficiently. A failure of a hub bearing (model B22459-464) is taken as an example in this paper. Impulsion characteristic of the failure is under direct vision through spectrum array analysis and spectrum analysis. Then peak index, kurtosis index, impulsion index and tolerance index of the vibration signal are calculated. These parameters represent the characteristic of failures. The result indicates that impulsion occurs to the bearing under given rotational speed. A time-frequency method-wavelet packets method-is applied to the vibration signal to extract resonate frequency in it. Afterward, envelop method is employed to demodulate the resonate signal, which reduces a characteristic failure frequency of 35.0Hz. This frequency is close to the characteristic frequency (37.3Hz in theory) of the roller. After dismantle, it's proved that the occurrence of impulsion is due to the flaking of one of the rollers.