| Summary: | Problem. The power and speed increase of modern internal combustion engines (ICE) leads to increasing of dynamic loads in power transmissions of machine units. Analysis and suppression of dangerous oscillations require taking into account in models development technological and constructive nonlinearities, which are the main reason for a varie-ty and complexity of dynamic processes: resonances shifts, deformation of resonance curves, multivalence of oscillations, and the appearances of subharmonic regimes. The known approaches to dynamic loads analysis in power transmissions of cars with ICE do not allow explaining the nature of certain phenome-na. The means for their study are not sufficiently de-veloped. Goal. To develop the nonlinear dynamic drive model for determining causes of dangerous dynamic loads; to find parameters of the device, which lead to dynamic loads reduction. The follow-ing problems solution: modeling of gaps in gears connections; schematization of the periodic disturb-ance of a non-harmonic character; chosing the form of the mathematical description for steady dynamic processes, taking into account the features of the nonlinear drive model; chosing the effective algorithm for solving the corresponding motion equations; carrying out calculation and experimental studies to reduce the drive dynamic loads. Methodology. For study of the established dynamic processes in nonlinear models of machine units, it is proposed to use the integrated equations of the movement which are written down by means of pulse-frequency characteristics (PFC) of the linearized models: the number of the nonlinear equations is equal to number of nonlinearities. Labor input of the solution of the task practically doesn’t depend on number of freedom degrees of system that is essential to numerical algorithms of the solution of the nonlinear tasks having iterative character at the solution of problems of synthesis and optimization. The algorithm of the solution of the nonlinear integrated equations is based on an iterative method of Newton-Kantorovich of the solution of the operator equations. During the numerical implementation of the algorithm for resolving linear integrated equations on every step of iteration process, the method of quadrature formulas in pair with the idea of interpolation of a desired solution is used. Results. A nonlinear dynamical model of the camshaft drive of the fuel pump of transport diesel has been created in the form of integral equations written by using of PFC. By calculation and experimental studies it has been established that: 1) an increase in the torsion shaft diameter leads to an increase in the maximum elastic moments; 2) increasing the inertia moment of the camshaft shift the resonant oscillations into the operating range; subharmonic oscillations are possible under action of a defined load; 3) the average moment in the drive not significantly affects the maximum elastic moments; 4) the one-way outputs realization to the drive retainer does not lead to the necessary dynamic loads reduction in the drive; 5) the maximal reduction of the maximum elastic moments can be done by using a spring with 15 mm diameter, which in combination with durable gears give the necessary drive reliability. Originality. The motion integral equations for the study of steady-state dynamic processes in non-linear models of machine units, written using PFC, have a number of principal advantages over the use of traditional models in differential form: the number of equations is equal to the nonlinear elements number, therefore, the solution time of problems is practically independent from the number of freedom degrees of models. Practical value. The studies carried out have allowed establishing the mechanism of dangerous dynamic loads appearance and giving recommendations on the drive parameters change, which provides its working capacity. The proposed approach is perspective for the dynamic processes study in models with nonlinear spring linkages, the number of which is less than the number of freedom degrees.
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