Influence of bearing material and clearance in a stern device on transverse vibrations parameters of a ship shaft model

The operating experience of the large-capacity vessels shafting illustrates a number of new technical problems, such as an increase in the number of accidents caused by damage to stern devices. A significant number of accidents associated with breakdowns of the propeller shafts due to exceeding the cyclic strength of their material, suggests the need for further study of the vi-brations of the shafting system. The creation of an experimental installation on the basis of the la-boratory of the ship shaft line of Astrakhan State Technical University provided experimental data under controlled test conditions. The design and operation principle of the experimental setup, which simulates the oscillations of a rotating shaft line model using various materials of shafts and bearings have been studied. The installation is a model of a ship shaft system, the shaft system of which is driven by an asynchronous electric motor. The speed of the shaft system can be adjusted using a frequency converter. Measurement and registration of vibrations is carried out using a hardware-software complex by the method of dynamic strain gauging. There have been shown the results of an experimental study of the parameters of transverse vibrations of a ship shaft model for various material of a stern bearing model and clearance in a stern device. The obtained dependences are represented by the Lagrange interpolation polynomial and response functions in the form of a second-order polynomial. Verification of the compliance of the regression model of data variability was carried out using a multiple coefficient of determination. Bearing material and clearance in a stern device have a significant effect on the frequency of the onset of an unstable state of the installation shaft. The research results can be used in the calculation of transverse vibrations of ship shaft lines.