Abstract: Planetary gearsystem is widely used in mechanical equipment which transmits motion and power. But its fault diagnosis is somewhat difficult. In this paper，by means of the traditional edgefrequencysignal recognition technique，the fault of a threestep planetary gearsystem is measured and analyzed. The analysis shows that the axis of the solargear of the first step deviates the theoretical axis, thus the axes of the planetary gears of the first step deviate their theoretical axes also. The eccentricity of these axes leads to large vibration and noise. In addition, modal analysis shows that the resonance of the planet gears happens due to the excitation of the large meshingimpulsion. Finally, the structure of the planetary gear system is improved, and a 2.5dB(A) noise decreasing is obtained.

Key words: vibration and wave, creeper gear, planetary gear system, frequency modulation, noise

摘要： 以传统的边频信号识别技术为手段，对某型号的三级行星齿轮减速器故障进行测试与分析，分析表明，该型减速器的第一级太阳轮的转动轴线偏离理论轴线，从而使得行星架和行星轮的转动轴线也偏离理论轴线，导致Ⅰ级的行星轮和Ⅰ级的太阳轮转动都出现了偏心，引起较大的振动与噪声。另外，对减速器进行的模态分析还表明，行星齿轮在较大的啮合冲击激励下发生了共振，加大了减速器的噪声。经对其结构进行改进，使其噪声下降了2.5 dB(A)。

关键词: 振动与波, 减速器, 行星轮系, 频率调制, 噪声