Research On Shafting Vibration And Simulation Electrical Marine

Marine propulsion shafting is an important part of the marine power plant, and its reliability is the basic condition to pledge these systems to work safely, so people always pay great attention to the operating state. The propulsion shafting is subjected to the various dynamic factors when it is running, including hydro-oscillation force, ship hull'distortion, lubricative oil force and so on. For the naval ship, shock forces such as contactile explosion, underwater uncontactile explosion and the bounce-back force caused by weapon's emission may probably befallen to the propulsion shafting, If the design quality of the shafting is not good enough, it will bring about undesirable shafting alignment results and exquisite shafting vibration, sequentially bring about engine block vibration, transmission system components damage, bearings excessive wearing, shaft break and so on, which not only pauses the normal running of the mechanical system, but also endangers the life safety of working personnel. So the shafting must be had a deeply research so as to get an accurate design, manufacture, installation and checking.With the developing of the electric propulsion, more and more motor take the place of traditional diesel engine. Compare to the traditional propulsion method,vibration on electric propulsion has greatly declined, but in some special ship, it has a higher requirements. This passage base on the electric propulsion marine, do some research on shaft bending and vertical vibration and the factors of these phenomenon.(1) First, work up the accurate model of shaft, in the passage propeller is simplified as homogeneous disc, so it is valuable to the relative research.(2) In this article considering the axial wake, it use chebyshev polynomials to fit the expression of the force and torque of electrical ship. Then simulate the propeller load characteristic in matlab/simulation tool box. In the end it get the value of force and torque produced by the propeller.(3) In the passage it use transfer matrix method to calculate the characteristics of ship shaft bending vibration, Considering the two factors (bearing distance, bearing stiffness) then analyze the affect on the shaft vibration, and give out the conclusion that compare to the other two bearings the first bearing play the most important role. In the five chapter it use laplace transform to compute the vertical vibration. In the end it show us the velocity amplitude frequency and time domain curve. From the curve it can conclude:Firstly with the increasing of bearing vertical damping the vibration amplitude decreased. Secondly from the velocity time domain curve it display that as the effect of bearing vibration velocity will be significantly reduced along the shaft.(4) ANSYS is a powerful analysis software, the passage analyze the shaft under condition of axial and horizontal force by ANSYS and give out the resultant displacement and resultant force. In the end the passage summarize the result of research and make the prospect of future work.