ABOUT DYNAMIC LOADS REDUCTION IN THE DRIVE TO THE CAMSHAFT OF THE FUEL PUMP OF TRANSPORT DIESEL

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ABOUT DYNAMIC LOADS REDUCTION IN THE DRIVE TO THE CAMSHAFT OF THE FUEL PUMP OF TRANSPORT DIESEL

Journal Title: Автомобильный транспорт - Year 2018, Vol 42, Issue

Abstract

Problem. The power and speed increase of modern internal combustion engines (ICE) leads to increas-ing of dynamic loads in power transmissions of ma-chine units. Analysis and suppression of dangerous oscillations require taking into account in models development technological and constructive nonlin-earities, which are the main reason for a variety 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 phenom-ena. The means for their study are not sufficiently developed. 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 algo-rithm for solving the corresponding motion equa-tions; carrying out calculation and experimental studies to reduce the drive dynamic loads. Method-ology. For study of the established dynamic process-es in nonlinear models of machine units, it is pro-posed to use the integrated equations of the move-ment 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 es-sential 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 inte-grated 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 equa-tions on every step of iteration process, the method of quadrature formulas in pair with the idea of in-terpolation 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 pos-sible 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 mo-ments 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 ma-chine 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 inde-pendent from the number of freedom degrees of models. Practical value. The studies carried out have allowed establishing the mechanism of dan-gerous dynamic loads appearance and giving rec-ommendations 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.

Authors and Affiliations

V. Shatokhin, B. Granko

Keywords

camshaft fuel pump transport diesel dynamic loads basic and subharmonic oscillations

EP ID EP408083
DOI -
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