Papers by Author: Xianfeng Fan

Abstract: Machine vibration signal has been used in fault detection and diagnosis. Modulation and non-stationarity existing in the signal generated by a faulty gearbox present challenges to effective fault detection. Hilbert transform has the ability to address the modulation issue. This paper outlines a novel fault detection method called Hilbert & TT-transform (HTT-transform) which combines Hilbert transform and TT-transform obtained from the inverse Fourier transform of the S-transform. The principle of the proposed method is to analyze the modulating signal created by a faulty gear using a time-time representation. The method has the advantage of providing a new way of localizing the time features of the modulating signal around a particular point on the time axis through scaled windows. It is verified with simulated signals and real gearbox vibration signals. The results obtained by CWT, S-transform, TT- transform, and HTT-transform are compared. They show that utilizing the proposed method can improve the effectiveness of gearbox fault detection.

Abstract: More precise analysis and design of generalized lubrication system with the research results of modern lubrication theories are the effective measures to improve the efficiency and reliability of internal combustion engine. Through discussing and summarizing the development status in this field, a set of systematic methods of integrated analysis and design, and general rules are proposed in this paper. Technical measures for lubrication design of internal combustion engine are given. The database of lubrication design and condition monitoring is suggested to found. The best dispose of lubrication system design will be obtained through modeling, deducing control equation, and numerical simulation, improving and optimizing the coupling relationship among the capacity design, structure design, and lubrication design. Such, the modern lubrication design can be combined with strength design at the period of concert design and scheme design period really.