The Influence of Parameters of Running Systems and Their Suspension on the Safety of Operators of Mobile Machines and Energy Equipment

Abstract

The scientific work is based on the tasks of applied research on initiative topics on the topic: «Substantiation of parameters and modes of interaction of the drive wheel with the soil», state registration number 0117U006833. The authors’ research is aimed at solving current problems of vibrational vibrations on the operators of technological means. All machines and mechanisms used by man in production and in everyday life are sources of various mechanical measurements and, accordingly, hazards. Of all the types of hazards caused by mechanical influences, vibration is the most dangerous for humans. It is human physiology that contributes to the negative effects of vibration. Due to the fact that the human body consists of hard bones, soft muscles, joints, various internal organs, it can be considered as a complex oscillatory system, the mechanical reaction of which depends on the parameters of vibration. At high frequencies (less than 2 Hz), the body responds to total vibration like a hard mass. At higher frequencies, the body responds as an oscillating system with one or more degrees of freedom. This is manifested in resonance increases in the oscillations of individual organs of the body at certain frequencies. It is for the sitting body position (in which the mobile operator is most of the time) that the resonance is at a frequency of 4-6 Hz.One of the most effective ways to reduce the negative impact of vibrational vibrations on the operator is to reduce the oscillations in the source of their occurrence, as well as the path of propagation from source to operator. This can be partially achieved, including the choice of rational pressure in the wheels of the vehicle, as well as high-quality and timely diagnosis of its individual components and units. This work is devoted to these important issues, and therefore its relevance is beyond doubt.In the scientific work the question of influence of a condition of a basic surface and geometrical parameters of a wheel of a tractor on speed of its movement and frequency of vibration fluctuations which arise at it is investigated. This issue is of considerable theoretical and practical importance, because the road and wheel oscillations caused by road irregularities cause a significant deterioration in the performance of the tractor. These issues have been studied by a number of researchers, but they have varied narrowly. That is why the task was to consider more deeply the connection between the state of the wheel and the coating with the parameters of vibration oscillations that occur during movement. In theoretical studies, the relationship between the length of the wheel chords and the irregularities between the two points of contact of the wheel was established. The support surface equation was represented by a sinusoid with a variable amplitude coefficient. Depending on the ratio of the radius of the wheel and the geometric dimensions of the protrusions and depressions of the support surface, two groups of equations were obtained that describe the parameters of vibrational oscillations. The results of analytical studies were illustrated by the corresponding geometric relationships. To verify the theoretical references, experimental studies were conducted with a system for measuring the parameters of vibration oscillations of controlled axles of wheeled agricultural tractors. The study was performed on two variants of the road surface. The results of experimental research are presented graphically in the form of oscillograms of vibration acceleration of the controlled axle of the tractor, as well as in tabular form. Theoretical and experimental studies show that there is an inverse relationship between the value of the wheel radius and the parameters of vibrational oscillations. As the translational speed of the tractor increases, the parameters of vibration oscillations also increase. The aim of the work is to reduce the negative impact of vibration load on the operator of a mobile vehicle by substantiating the rational parameters of the wheel and determining the location and method of diagnosing its individual components and units. To achieve this goal you need to perform the following tasks: determine the causes of injuries in the operation of mobile vehicles; to analyze the harmful effects of vibration oscillations on the mobile operator; identify ways to reduce vehicle vibrations; to carry out mathematical formalization of the process of oscillations of the operator’s workplace; to build a mathematical model of oscillations of the system «road – vehicle – operator».In this research we used research methods to determine theoretical data based on mechanical and mathematical modeling of the interaction of elastic propulsion and curved support surface using the basic principles of theoretical mechanics and higher mathematics.