说明：  本文研究了齿轮振动信号调制与解调的过程与机理。并根据希尔伯特变换理论,提出了一种早期诊断齿轮故障的新方法
(In this paper, a gear vibration signal modulation and demodulation process and mechanism. Hilbert transform theory, proposed an early diagnosis of gear failure method)