This paper reports results of studying the influence of geometrical parameters of the frame in a traction-transportation vehicle on its traction and energy indicators. A method for estimating the influence of geometrical parameters of the frame in a traction-transportation vehicle on its traction and energy indicators has been substantiated, based on the traction calculation of the tractor and taking into consideration the change in the distance from the hinge of the traction-transportation vehicle to the front and rear drive axles. The method makes it possible to determine the normal reactions, tangent thrust forces, and traction power on the wheels of the machine. The method reported here enables defining the optimal geometric parameters for improving the traction-adhesion and fuel-economic indicators of the traction-transportation vehicle. It was theoretically established that the normal reactions on the front wheels of the studied traction-transportation vehicle are 27,800 N and exceed by 1.95 times the normal reactions on the rear wheels of 14,200 N. This is due to the fact that the distance from the hinge to the corresponding axles of the wheels is 1.89 m and 0.97 m. Increasing the distance from the hinge to the axle of the rear wheels to 1.17 m produces a positive effect on improving the tractive performance of the traction-transportation vehicle. There is an increase in the tractive power on rear wheels to 24.39 kW. The experimental study of the traction-transportation vehicle was performed using an all-wheel-drive machine with a hinge-connected frame as an example. The maximum traction power is 121 kW, which is achieved at a speed of 12 km/h, traction efficiency of 0.68, and a thrust force per hook of 30.2 kN. The difference between the results obtained theoretically and experimentally is 8 %. Applying the method could make it possible to provide designers and manufacturers with recommendations for the construction and improvement of a traction-transportation vehicle, to improve traction and adhesion properties, and reduce the anthropogenic impact on the soil
When separating (cleaning) lightweight seed mixtures with the help of vibratory machines, there is an issue related to the harmful effect of air movement in the gaps between parallel working surfaces of vibratory machine units. This factor is particularly harmful to seed material, which is sensitive to air movement (some medicinal and vegetable crops). To address this issue, the design of vibratory machines is changed while their operational regimes are configured accordingly. This requires many full-scale experiments and (or) time-consuming personal computer-based simulation of the working processes of the vibrational motion of such seed mixtures. This paper proposes several regression models that make it possible to replace time-consuming numerical modeling with simple analytical expressions (regression equations). These equations are used for a quantitative assessment of the degree of influence of aerodynamics on the kinematic parameters of the vibrational motion of particles of seed mixtures. The assessment is derived depending on the geometric characteristics of the aerodynamic screen, the design of the unit, and the amplitude of oscillations of the working surfaces of a vibratory machine. The models take the form of equations of multiple linear regression of the second order, obtained on the basis of a series of numerical experiments. The processes of vibration movement of the seed material of parsnips, lettuce, and fragrant dill were investigated. The coefficient of determination equaled 0.956...0.967. The results reported here are useful for the construction of algorithms to optimize the design and adjust the operating modes of vibratory separators according to the criterion of minimizing the harmful effects of the aerodynamic factor
The results of a study of dynamic and traction-energy indicators of an all-wheel drive wheeled traction-transport machine are presented. A diagram of a dynamic transmission model for an all-wheel drive wheeled traction and transport machine and a system of equations for the transmission dynamics in the Cauchy form have been compiled. This made it possible to determine the dependences of the angular speeds of rotation of the transmission elements of the traction-transport machine, the dependences of the torques and the dependences of the contacting traction forces on the wheels on time. The method allows to determine the optimal transmission parameters, differential designs and gear ratios to improve the traction and coupling and fuel-economic performance of the machine. It has been established that the angular speeds of rotation of the front wheels of the traction-transport machine 1.29 rad/s, 1.27 rad/s are higher than the angular speeds of rotation of the rear wheels 1.24 rad/s, 1.25 rad/s, which leads to the appearance of a kinematic discrepancies and additional energy losses. The torques of the front drive wheels are 6972 Nm, the rear drive wheels are 4622 Nm. The contacting traction forces on the front wheels of the machine are 5478 N after the end of the acceleration of the machine, on the rear wheels – 3473 N. Experimental studies were carried out on the example of an all-wheel drive wheeled tractor with an articulated frame to validate the method for assessing the dynamics of the traction-transport transmission. The difference between the values of the angular speeds of rotation of the wheels and the tangential traction forces on the wheels, determined theoretically and obtained during experimental studies, is 2 %. The developed method for assessing the transmission dynamics of an all-wheel drive traction and transport machine should be considered valid. The method proposed in the paper can be used to assess the dynamics of wheeled machines
Надзвичайною різноманітністю умов характеризується робота трактора у сільськогосподарському виробництві. Визначено, що найбільший вплив на режими роботи трактора мають ґрунтово-кліматичні умови, раціональність комплектування тракторних агрегатів, рівень культури землеробства, стан доріг у господарстві, обґрунтованість використання тракторів на тих чи інших роботах, кваліфікація водіїв та багато інших факторів. Тягове навантаження на гаку трактора є нестаціонарною випадковою функцією часу. Встановлено, що характеристики тягового навантаження залежать від складу агрегату, виконуваної роботи, неоднорідності фізичних властивостей ґрунту та мікрорельєфу поверхні поля або дороги. Визначено математичні очікування потужності, що витрачається двигуном при розгляді всього комплексу сільськогосподарських машин (Nд) = 48,75 к.с. Для сільськогосподарських машин, що працюють без відбору потужності через вал відбору потужності (Nд) = 49 к.с. Експериментальна крива розподілу дійсних швидкостей руху агрегатів показує, що середня швидкість машин, що працюють без відбору потужності через вал відбору потужності, становить (nд) = 2,13 м/с (7,7 км/год). Встановлено, що при роботі з ґрунтообробними та збиральними машинами швидкість не перевищує 3,34 м/с (12 км/год). Середнє значення тягового зусилля для трьох серій експериментальних досліджень сівалки Вега-8 складало Рср = 18 кН. При швидкості руху u = 1,45 м/с розмах коливань тягового зусилля сівалки складав DР = 13269 Н, а з підвищенням швидкості до 2,3 м/с розмах коливань тягового зусилля підвищився до 18305 Н. Максимальне значення розмаху 20842 Н спостерігається на швидкості 4 м/с
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