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Shaft fault is the most common fault for hydraulic machinery. In this paper, wavelet packet energy spectrum analysis method was used for multi frequency bands division of shaft monitoring signals. The variable bands frequency energy can construct feature vectors needed for fault diagnosis based on support vector machine, by integrating the procedure of wavelet packet analysis method and online monitoring technology, feature can be extracted in real time, and it make possible for real-time fault diagnosis and prediction of hydraulic machine.

TiC-TiB2 composite ceramics were successfully fabricated via planetary ball milling of 72 mass% Ti and 28 mass % B4C powders, followed by low temperature sintering process at 1200°C. The microstructure of the ball-milled powder mixtures and composite ceramics were characterized by Differential thermal analysis equipment (DTA), field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The results showed that the ball-milled powder mixtures (Ti and B4C powders) were completely transformed to TiC-TiB2 composite ceramics as the powders were milled for 60 h and sintered at 1200°C for 1 h. The formation mechanism of the TiC-TiB2 composite was discussed. The high energy ball milling and necessary sintering for the powder mixtures plays an important role in the formation of the composites.

In this paper, shaft monitoring data in condition monitoring system of hydropower units was used to build the fault classification model based on the least square support vector machine (LS-SVM). By the wavelet packet signal decomposition for unit vibration signal, setting the signal energy components as the study sample, learning of fault diagnosis classifier was conducted, to achieve the diagnosis of common faults in shaft running of hydropower unit.

In this paper, the basic concept and specific steps of establishing skew bevel gears mathematical model using conjugate meshing principle was introduced. Numerical value counting function of MATLAB was used to collect coordinate of tooth surface grid point, and under the Pro/E environment, data document of coordinate created by MATLAB was imported to establish tooth surface modeling , relying on the powerful function of complicated curve modelling, 3D solid modelling of gear was completed. The results via motion analysis kinematics analysis and interference inspecting under assembling condition show the accuracy of the design ,which supports further design, analysis and manufacture.