Study On The Shafting Alignment And Axis Orbit

Ship shafting is the major part of the marine power plant and the quality of shafting alignment is very importance in ensuring the long term appropriate running. According to the change of factors, such as the ship loading condition, status of the sea voyage regional etc. the poor working conditions of the ship shafting leads to increased wear or even burning stern bearing, so it is necessary to seek a feasible way to monitor the running state of the ship shafting. Especially for the installed shaft in operation process, the inspection and evaluation of actual shafting alignment is rarely in the domestic and international research. Based on this, the paper puts forward a method of using the axis orbit to evaluate the state of the shafting alignment. As an important graphic signs of the rotor vibration signal, a large amount of information is contained and the state of equipment operation can be visual displayed. Ship shafting is larger length-diameter ration than general rotating machinery and the research on its axis orbit not only for fast and effective evaluation of shafting alignment quality, but also the ship shafting on-line monitoring and fault diagnosis expert system, have high application value.Firstly, the paper analyzes the ship shafting and point out the characteristics of the axis orbit. Based on the general layout principle of the ship shafting, the bench of ship shafting is built for the study. Considering the actual working environment, foundation of the bench adopts the ship double bottom structure. It can simulate the deformation of the hull.Secondly, application of finite element analysis software ANSYS, the finite element model of the ship shafting is established. Using the model, the paper obtain the bearing load and shafting deflection, rotation, shear and bending moment at the calculation of straight and rational shaft alignment.Finally, with the Eddy Current Sensor which was installed in each bearing, the original axis orbit was obtained. With the wavelet analysis, comparing the purification effect of using different wavelet function and decomposed into different layers, the axis orbits are obtained. Under the state of straight and rational shaft alignment, the axis orbit of each bearing are consistent with the calculation result of shaft alignment and the paper obtains the preliminary result of dynamic quantitative description of ship shaft.