The increase in the energy saturation of the new models of tractors "Belarus", as well as the mass of towed trailers and agro-technological tools that are mounted with them, required an increase in the efficiency of the tractor braking system. The purpose of the study is to increase the efficiency of the braking system of the wheeled tractor "Belarus MTZ" by creating wheel brakes for the front axle with minimal changes in its standard design. The developed drum brake with hydraulic drive of the front drive wheels of the tractor "Belarus MTZ-1221" does not require significant changes in the standard design of the front axle of the MTZ tractor and is adaptive to the anti-lock system, which operates on the basis of measurement and analysis of force factors. The design of the developed brake mechanism allows its adaptation to the anti-lock system, which operates on the basis of measuring and analyzing the forces that arise in the contact of the wheels of the front axle of the tractor with the supporting surface. The braking effect of the tractor "Belarus MTZ-1221" is provided by additional use of its coupling weight, which falls on its front axle. A set of design documentation for the drum brake for the front driving wheels of the tractor "Belarus MTZ-1221" was developed. The use of an additional traction weight of the tractor due to the wheel brakes of the wheels of the front axle of the tractor "Belarus MTZ-1221" will increase the efficiency of its braking, as well as increase the competitiveness of wheeled tractors produced by the JSC "Minsk tractor works". Bench tests confirmed the possibility of braking the calculated moments corresponding to the weight load on the front axle of the tractor "Belarus MTZ-1221". Consequently, the developed brake mechanism will ensure effective use of the tractive weight of "Belarus MTZ-1221" tractor.

When cabbage is traditionally machine-cleaned, its heads are mechanically damaged to a considerable extent, which reduces their shelf life during storage. The bulk of the damage is attributed to the processes of shipment of the heads to the body of the vehicle in bulk and unloading it when laying cabbage for storage in the coats. In existing designs and well-known works, no practical solutions were found, which could be realized with maximum efficiency in harvesting cabbage. In this regard, the aim of the study is to substantiate the design and basic parameters of the device for the careful shipment of cabbage heads during machine harvesting. For this purpose, a new method for machine harvesting cabbage is proposed (patent RF 2554403), where, unlike the traditional method, the head is first shipped in a sparing mode on a flexible trough-shaped flooring installed on a special rack above the detachable containers in the body of the accompanying vehicle. Then the heads from the flooring are gently transferred to containers for subsequent storage in them. The efficiency of the use of the proposed device and the degree of reduction of head damage in the process of shipment depends on its design and correct justification of the parameters. The nature of the flow of the process of shipment of heads is essentially dependent on the type of sagging curve of the trough-like form of the flooring. For the purpose of substantiating the design and parameters of the device for careful shipment of cabbage heads during machine cleaning, a mathematical model of the construction is proposed, using which the necessary parameters of the proposed device are determined.

Using fertilizers, in line with other agrotechnical activities, is one of the most important means for increasing soil fertility, as well as agricultural products performance. Domestic and foreign experience shows us that yield capacity can grow almost 1.5-fold due to fertilizers. Nowadays the surface type of using hard organic and mineral fertilizers by means of body spreaders is considered to be one of the simplest technically and most effective ways. Being the object of the research, the experimental mineral and organo-mineral granular fertilizers spreader is a van-type lowboy, equipped with a belt conveyor and a vertical rotor with a horizontal axis of rotation. In addition to load bearing characteristics, rotational movement of the operative parts in the casing of the rotary drum provides for air drag, which influences the trajectory of fertilizers flight. Pattern of fertilizer distribution, flight distance of fertilizer particles and horsepower input of the gear system depend on the design features of the operative parts of the pneumatic-mechanical rotor. The objective of the research is to define travel speed of fertilizer particles along vanes in case of constant fertilizer input with air drag in versions with radial position of vanes, bent backwards and forwards to some angle. The main research techniques are a graphical and analytical method and analysis of the component force which operates on the blade's surface. As for the drum with a diameter of 920 mm, at rotation frequency of 850 min-1, the best performance was shown by the through blade. They may reduce the friction force of the casing of rotor. Besides, they can concentrate fertilizers in the center of a blade, and achieve qualitative work of the fertilizer spreader, is ascertaining.

The rolling radius of the wheel is considered as a result of normal and circumferential deformations of its pneumatic tire, caused respectively by the normal load and the torque applied to the wheel. Consideration of the normal deflection of the tire enabled the value of the rolling radius of the driven wheel to be represented as a function of the axial load per wheel and the radial rigidity of the tire. To assess the adequacy of the developed model, the example of the 26°-2° tire used in trucks is used to calculate the kinematic radius for different values of the normal load. Analysis of the calculation results shows that the kinematic radius of the driven wheel decreases linearly with increasing normal load. This is in good agreement with the results of previous experimental studies. When considering the action of torque, it is considered that it causes a tangential (circumferential) deformation of the tire, i.e. its twisting, as a result of which the rim of the wheel makes a certain turn relative to its periphery. In this case, this rotation of the rim is not accompanied by a longitudinal displacement of the axis of rotation of the wheel itself. Since the torque breaks the single-valued relationship between the linear and angular velocity of the wheel, this is reflected in the kinematic radius of the wheel. Based on the dependence of the twist angle and torque, an analytical dependence of the rolling radius on the algebraic magnitude of the torque and the torsional rigidity of the tire is established. Calculation of the rolling radius of the wheel, carried out according to this formula, shows that when the torque is applied, a linear decrease in the rolling radius occurs, and when the braking torque is applied, on the contrary, its linear increase is shown. Such a change in the rolling radius completely agrees with the results of experimental studies of various types of pneumatic tires.

A brief review of the systems of precise farming is given, problems of scientific and practical research are formulated to create a domestic system of accurate farming using autopilotation. The analysis of applied software used in the development and approbation of algorithms for controlling the movement of wheeled agricultural machines is carried out. The ideology of the development of mechatronic systems using the CAMeL-View application package is presented, a mechanical-mathematical model of the machine-tractor unit consisting of a wheeled tractor and a semi-mounted plow is described. The results of mathematical modeling of the movement of a machine-tractor unit at a speed of 2.5 m / s are presented using control based on the basic maneuvers of wheeled vehicles when the soil is processed to a depth of 0.24 m. The required slope angle of the tractor frame is defined as a linear combination of dependencies for changing the curvature of the trajectory, the direction of motion, the lateral displacement and the initial angle of rotation of the steered wheels. The analysis of the results allows to draw a conclusion about the rather good quality of the working movement of the arable unit, which indicates the efficiency of the proposed control algorithm. The program implementation of the control algorithm is proposed in the wheeled agricultural machines developed with the participation of authors of the electromechanical control system for the movement using satellite radio navigation systems GLONASS and GPS. With a real control of the movement of a wheeled agricultural machine, a significant deterioration in the quality of motion is caused by inaccurate determination of its current coordinates when using satellite GPS and GLONASS radio navigation systems. Accordingly, the level of lateral deviations of the working mechanisms of the agricultural machine will be higher than the motion obtained from the modeling results, using the proposed control algorithm. The final conclusion about the limits of applicability of the proposed control for various fieldwork will be made based on the results of field tests of the control system.

Nowadays rubber-reinforced tracks found wide application on different purpose traction and transportation vehicles due to well-known advantages, including possibility of their installation instead of metal linked tracks without significant modernization of undercarriages structures. The operational experience of vehicles with rubber-reinforced tracks shows that their construction differences in comparison with metal tracks provide increased loading to crawler outline, especially to drive sprockets. It shows on necessity of individual drive sprockets design for rubber-reinforced tracks. Special methods for this are absent and traditional methods intended for metal tracks do not provide reliability and efficiency of track engagement. The article contains the special designed method of pin engagement drive sprockets with rubber-reinforced tracks engineering. Practically established that rubber-reinforced track bending is going through the broken line in conditional joints and the engagement element with the drive sprocket tooth is spool of inset element with the part of reinforce lay. All the necessary analytical dependences for drive sprockets design and calculation are shown. The optimal values of contact angle for real constructions of rubber-reinforced tracks, when the normal teeth form is provided; analytical dependences of kinematic pitch circle and bottom circle radiuses for different variations of conditional joints are determined. Boundary conditions for optimal values determination of drive sprockets width and thickness and also their heads radius are accounted. The efficient options of drive sprockets teeth profile curves plotting are shown. The developed design method of pin engagement drive sprockets with rubber-reinforced is based on typical methods for metal tracks and takes into account structural features of rubber-reinforced tracks. It provides reliability and efficiency of track engagement and can be used in design process of traction and transportation vehicles undercarriages.