RESEARCH OF TESTING METHODS OF HYDRAULIC POWER STEERING OF TRACTORS

Abstract Purpose of the study. The purpose of the study is to increase the level of technical readiness of tractors based on indicators of the technical state of steering by improving the process of its diagnosis. In order to achieve the goal, it is necessary to substantiate the estimated indicators and develop a method of testing the hydrovolume steering of tractors using the method of partial accelerations. Research methods. The methodological basis of the work is the use of the method of partial accelerations. This method is based on the transition from the vector sum of forces in space to the vector sum of accelerations in space. This makes it possible to preserve the physical essence of the obtained vector equation describing the motion of the dynamic system. The method of partial accelerations, in contrast to classical methods, involves reducing the equations of dynamics to the equations of kinematics (principle of kinemodynamics). Further research is based on this principle. The results of the study. A method of testing hydraulic volumetric steering of tractors using the method of partial accelerations has been developed. The time of rotation of the tractor wheels from the extreme position to the extreme position is an indicator for diagnostics. It was established that the duration of turning the tractor wheels from the extreme position to the extreme position is correlated with the accelerations that occur in the front and rear half-frames of such a tractor. The rotation accelerations of the rear half-frame are more pronounced, compared to the accelerations of the front half-frame. This is explained by the different values of their mass index. Measurement of the indicator is possible using the method of partial accelerations. For this, measuring complexes based on accelerometers are used. Conclusion. The implementation of methods for assessing the quality of tractor steering units and the units developed according to the proposed methodology will allow for an accelerated assessment of their compliance with technical conditions and traffic safety during tests and in operation. The application of partial accelerations method makes it possible to make a conclusion about the technical condition of the elements and nodes of the hydraulic steering of the tractor without the presence of a special platform for running tests. As a diagnostic indicator, the longitudinal component of acceleration that occurs when the guide wheels turn is proposed. The labor intensity of tests using this method is reduced by 3.28 times compared to the known ones, and the consumption of working fluid is also reduced by 2.7 kg, as the operation of disassembling units is eliminated. Key words: tractor, hydraulic power steering, test, turning time, condition indicator, method.