The analysis of the work of tillage machines is carried out, the reasons for the failures of their working bodies (plowshares) during operation are revealed. Research has been carried out on the change in the characteristics of the material of the cutting elements of soil-cultivating machines after vibration hardening, as well as the effect of hardening on the strength of restored plow shares. The parameters of vibration hardening of plow shares are experimentally determined. Microstructural studies were carried out in order to reveal the influence of the processing method on the properties of the plowshares material. Criteria for the limiting state of plowshares are revealed. Bench tests of plow shares at the installation allow you to adjust the intensity of their wear. It has been established that the depth of wear of the ploughshare material is the most significant geometric parameter affecting its resource. Experimental studies have established the values of the main parameters of vibration hardening: the frequency and amplitude of oscillations of the working working tool and the hardening time. The values of the degree of hardening of the material of the cutting edge of the reconditioned plow shares have been determined. The relationship between the values of the change in the width of the ploughshare and the thickness of its blade during deformation has been established. It was found that, in addition to the processing modes, the shape of the processing tool affects the geometry of the share. An uneven wear pattern along the length of the share is revealed. The results of changes in the wear along the width of the cutting element and the intensity of its wear depending on the operating time are given. It has been established that the amount of wear of the plowshare cutting element depends on the technological modes of processing and the material. Conducted bench studies of the specified variants of plowshares in order to check the operational reliability of the restored and vibration-hardened plow shares. It was found that the plowshares made of 65G steel, treated by vibration hardening, had the lowest wear rate, which is explained by the change in the structure of its material during vibration hardening.

The paper deals with the use of vibration vibrations in the restoration of the working bodies of agricultural tillage machines operating under conditions of increased abrasive wear. The analysis of the existing methods of their restoration is carried out, the substantiation of the use of vibration hardening treatment in repair production is given. The research carried out on the choice of the optimal parameters of vibration strengthening of the cutting working bodies contributes to an increase in the wear resistance and reliability of soil cultivation equipment. According to the research results, the change in hardness along the depth of the surface layer of cutting elements of the following agricultural tillage machines: plow shares, opener discs of grain seeders and cultivator paws was established. Optimal values of the main parameters of vibration processing of cutting elements of the specified working bodies are experimentally determined and substantiated, which reduce the amount of their wear: amplitude A and vibration frequency of the processing tool n, hardening time t. The change in the magnitude of linear wear along the width of the cutting elements of these parts is shown, as well as data on the intensity of their wear. Experimentally obtained data on the absolute and relative wear of the diameter and thickness of the blade of the opener discs, which made it possible to choose a more efficient technology for their restoration. According to the research results, it was found that the specified parts of soil cultivation equipment had the least wear value; they were restored by welding tires, plates or segments from steel 45, followed by surfacing with sormite and strengthened by vibration deformation. The results of the work will be used to develop technological processes for the restoration of other working bodies of tillage machines by the method of vibration deformation. Annotation The paper deals with the use of vibration vibrations in the restoration of the working bodies of agricultural tillage machines operating under conditions of increased abrasive wear. The analysis of the existing methods of their restoration is carried out, the substantiation of the use of vibration hardening treatment in repair production is given. The research carried out on the choice of the optimal parameters of vibration strengthening of the cutting working bodies contributes to an increase in the wear resistance and reliability of soil cultivation equipment. According to the research results, the change in hardness along the depth of the surface layer of cutting elements of the following agricultural tillage machines: plow shares, opener discs of grain seeders and cultivator paws was established. Optimal values of the main parameters of vibration processing of cutting elements of the specified working bodies are experimentally determined and substantiated, which reduce the amount of their wear: amplitude A and vibration frequency of the processing tool n, hardening time t. The change in the magnitude of linear wear along the width of the cutting elements of these parts is shown, as well as data on the intensity of their wear. Experimentally obtained data on the absolute and relative wear of the diameter and thickness of the blade of the opener discs, which made it possible to choose a more efficient technology for their restoration. According to the research results, it was found that the specified parts of soil cultivation equipment had the least wear value; they were restored by welding tires, plates or segments from steel 45, followed by surfacing with sormite and strengthened by vibration deformation. The results of the work will be used to develop technological processes for the restoration of other working bodies of tillage machines by the method of vibration deformation.

The object of research is the technological process of increasing the service life of pointed cultivator shares of tillage machines through the use of a progressive method of vibration hardening. One of the most problematic areas is the inadequate study of the investigated technological process of restoring the working bodies of agricultural machines. In order to gain a deeper understanding of the process of vibration processing of the material of these machine parts during their restoration, it is necessary to conduct further experimental studies. In the course of the study, it has been found that the use of vibration deformation of the surface layer of the material of parts contributes to an increase in their resource. The optimal parameters of vibration hardening of the cutting elements of the cultivator shares of tillage machines have been determined, which makes it possible to increase their durability. The main parameters of vibration hardening are revealed: the vibration amplitude of the processing tool is 0.75 mm; vibration frequency – 1400 min–1; hardening time – 30 s. As a research result, the assessment of the change in linear wear along the width of the cutting element of the cultivator duckfoot of tillage machines was carried out. In cultivators with tines restored by welding angle plates made of 45 steel (GOST 1050-2013, GB 699-88), sormite surfacing and vibration hardening, the linear wear rate by weight of cutting elements is 35–43 % less than in new tines. A study of changes in the wear of the cutting edge of cultivator shares was carried out, which, when restored by welding corner plates made of steel 45 (GOST 1050-2013, GB 699-88), surfacing with sormite and vibration hardening, is 1.57–1.68 times less than in new shares. In comparison with existing technologies, the developed technology provides a reduction in the wear of cutting elements by 10–17 %, in comparison with new ones made of 65G steel (GOST 14959-2016, GB 1222). The coefficient of technical utilization of the cultivator with tines restored according to the developed technology, in comparison with the new ones, is 1.07 times higher.

The current trend of recent decades is the growing role of the automated electric drive built on the basis of asynchronous electric motors. This is connected both with the development of theoretical approaches that allow to model the behavior of the latter with high accuracy, and with a significant increase in reliability and a decrease in the cost of power semiconductor technology, which in turn made it possible to improve operational characteristics and reduce the cost of such systems as a whole. The consequence of this trend is that asynchronous motors are increasingly used not only in classic electric drive systems with easy starting conditions, but also increasingly used in traction electric drives and electric drives with large starting moments, which were traditionally implemented on the basis of direct current motors. This circumstance leads to the appearance of additional technical difficulties in the design and operation of asynchronous electric motors, which is associated with the peculiarities of their natural mechanical characteristics, which have a slightly underestimated value of the starting torque. And although this shortcoming can be eliminated by increasing the power reserve of the engine when designing the electric drive, such a compromise solution will have significant disadvantages associated with a decrease in efficiency and an increase in the cost of the electric drive as a whole. It is obvious that this circumstance determines the need for further theoretical research aimed at improving the starting characteristics of asynchronous motors. Considering what has been said, today the induction motor remains the most common electric machine used in various fields of activity. Moreover, the share of asynchronous motors used in industry is growing rapidly, and the scope of their use is constantly expanding. A. therefore, the development of a mathematical model of the dependence of the starting torque on the angular position of the rotor, which in the future would allow improving the starting characteristics of asynchronous motors, is an urgent scientific and applied problem that has significant practical value. In the article, the equation of the dependence of the starting torque of an asynchronous motor on the initial position of its rotor is obtained, which makes it possible, taking into account the design features of the AD, to uniquely calculate the value of the mechanical torque that occurs on the motor shaft when it is started with the nominal supply voltage. The mathematical dependence of the deviation of the AD starting moment on the initial rotation angle of the rotor was obtained, which can be used as a corrective mathematical model of the AD control system. The simulation of the dependence of the torque of an asynchronous motor on the initial position of its rotor was carried out, which made it possible to confirm the adequacy of the obtained mathematical dependence. It is shown that the change of the starting torque during rotation of the AD rotor occurs according to the sinusoidal law. It is theoretically proven that deviations of the starting torque at different initial angular positions of the rotor can reach ± 6.5% of the nominal value.