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This paper proposes an experimental method for studying the Sommerfeld effect in auto-balancers or exciters of resonant vibrations of pendulum, ball, or roller type. The method is based on the processing of signals acquired from analog sensors of rotations and vibration acceleration using regression analysis. The method is tested on a specially designed rotor bench on isotropic viscoelastic supports, which executes spatial motion, and an auto-balancer with one ball. Checking the accuracy of the method using stroboscopic lighting demonstrates the accuracy of determining the speed of rotation of the rotor, ball, oscillation frequency of the rotor, etc. with an error of several hundredths of a percent. When fixing the ball relative to the rotor, a classic inertial vibration exciter is obtained. The rotor has two resonant velocities. The Sommerfeld effect is almost not manifested. With a gradual increase in the frequency of the current, the rotor speed increases monotonously. There is no significant slip or jump in the rotor speed. There are two distinct peaks on the amplitude-frequency characteristic. Therefore, such a vibration exciter is not suitable for the excitation of resonant vibrations. With the free placement of the ball in the oil, the behavior of the system changes significantly in the vicinity of the first resonant velocity. The first narrow resonant peak disappears in the roto. Instead, there is a long, gentle resonant rise. It lasts at a current frequency of 9.4Hz to 19.3Hz. The amplitude at the reference point on the resonant rise increases from 0.7mm to 2.84mm. Therefore, by changing the frequency of the current, it is possible to smoothly change the amplitude of the rotor oscillations by almost 4 times. The maximum amplitude of rotor oscillations is the same as at the first resonance with a fixed ball. Due to the gentleness of the resonant rise, a freely installed ball itself is a reliable exciter of resonant vibrations

The article analyzes the cargo forged unicorn hook. The design parameters of the product are substantiated by building a solid model of the hook. The line of cargo hooks with the changed form of sections which theoretically allows to reduce weight by 10% at preservation of loading capacity is offered. Comparison of standards shows that at equal loading capacity at identical classes and groups of classification the size and mass characteristics of products differ in times, and not in all cases in favor of standard hooks. Operational tests show that the shape of the hook must ensure its minimum weight with sufficient strength, if possible the same in all sections when the operating conditions and manufacturing technology. It was found that the contours of the upper and lower parts of the cross sections of the hooks are not subject to change. The geometric ratios of the cross-sectional dimensions of the hooks, as well as the threaded part can be considered determined theoretically and experimentally as optimal. Changing the contour is carried out by replacing the rectilinear sides of the trapezoid sections with curved ones. The obtained pictures of stress distribution in the hook body make it possible to choose the path of design optimization in the direction of changing the contours of the equatorial and meridional sections of the fourth quadrant of the hook contour. The proposed change of the contour is carried out by replacing the rectilinear sides of the trapezoidal sections with curved ones. The stress-strain state with visualization and stress distribution is presented, the parameters of the hook are substantiated by building a solid model in the CAD complex Solidworks. The study of the stress distribution pattern made it possible to propose cross-sectional shapes with the subsequent calculation of the stress-strain state of the created model. Material consumption efficiency due to the optimization increases by 10.8% without reducing the load capacity. The changes in the maximum displacement in the proposed model are insignificant (2.55 mm vs. 2.33 mm in the model GOST 2105-75). Recommendations proposed based on the study of one model configuration can be extended to others, taking into account the technology of manufacturing the product.

The purpose of the work is to improve the quality of the process of running-in of car engine parts during running-in using the additive of complex action. The tasks are the theoretical substantiation of the formation of transfer films during engine running-in and the conduct of comparative studies of the developed complex additive to M-8-B motor oil. The paper substantiates that in order to improve the quality and accelerate the running-in of car engine parts during running-in, a complex additive is required, which includes both surfactants and chemically active substances. The preconditions for obtaining transfer films on the friction surfaces of engine connections during running-in are considered. A frictional interaction is described in the case when the soft transfer film is strong and fixed on the main material, and the sliding surface coincides with the boundary between the film and the counter body. The presence in the zone of contact of surfactants with metals leads to the implementation of a special mechanism of frictional interaction, characterized by a colloidal system of particles in the lubricant and structural transformation on the interface. Comparative laboratory studies of the proposed additive were performed. The dependence of the moment of friction force on the time of the tests, the surface roughness of the samples worked in different compositions, as well as the distribution of the microhardness of the samples by depth were investigated. Based on the analysis of additives for running-in of engine parts, the use of complex additives containing surfactants and chemically active substances is determined as promising. Based on these studies, an additive containing ferrite spinel has been proposed. This allows you to control the running-in process through the structurally sensitive properties of the spinel composition. The use of the proposed additive of complex action helps to change the structure of the surface layer of the metal during friction under the action of temperature and load, which leads to improved quality of running-in of car engine parts during running-in.

The analysis of the basic parameters of the dosage of molten iron in metal forms using the magnetodynamic installation MDN-6CH. A schematic diagram has been developed for controlling the electromagnetic systems of the unit. The technology of dosing and pouring metal into the chill mold has been developed in the manufacture of cast iron balls with a diameter of 40 and 120 mm. At the optimal casting temperature, the electrical parameters of the inductor (voltage Ui, current Ii, power Ri) were in the range Ui = 250-300 V, Ii = 480-520 A, Ri = 140-160 kW. When reducing the mass of metal in the crucible MDN-6CH using a control scheme made switching inductor from a voltage of 300 V to 250 V. The power was reduced by 15-20 kW, and the temperature of the metal remained within the tolerance of the technology of metal casting. Using the adopted dosing scheme, it became possible to cast metal at constant parameters of the electromagnetic system and the time of pouring. The technology of dispensing and pouring metal into the mold for the production of cast iron balls with a diameter of 40 and 120 mm was carried out at an inductor voltage of 300 V, and the electromagnet - 220 V. The initial level of metal on the drain socket was equal to 20 mm. The molding time of molds in the manufacture of balls with a diameter of 40 mm was 7.3 s, and balls with a diameter of 120 mm - 16.2 s. The operating time of the electromechanical actuator was set in the manufacture of balls with a diameter of 40 mm - 0.35 s, and balls with a diameter of 120 mm - 0.75s. The consumption of metal in the manufacture of balls with a diameter of 40 and 120 mm was in the range of 0.7-0.75 kg / s and 1.65-1.70 kg / s, respectively. The metal casting was carried out at temperatures of 1320-1340 ° C and 1360-1380 ° C. The dosage accuracy was determined by weighing the metal of the poured balls and the molding system of the mold. Mathematical processing of the results of the dosing showed that in the manufacture of balls with a diameter of 40 mm at a temperature of 1320 °C the error of dosing is 10-11%. With increasing iron temperature, the dosage error decreases and at a metal temperature of 1370 °C is 5-6%. In the manufacture of balls with a diameter of 120 mm at a temperature of iron 1330, the dosage error is 7-8%, and at a temperature of 1360 ° C - 3-4%. The study of the characteristics of the casting and dosing process of cast iron in the chill mold allowed us to develop the technology of casting cast iron melts, which provided the required metering accuracy and high productivity of the conveyor production of grinding bodies.

During the operation of mobile agricultural and motor vehicles, their connections and parts are activated. This leads to a decrease in traction power, operating speed, quality and productivity when performing technological operations. Repair costs are constantly rising, so the question of finding inexpensive technologies for the restoration of worn parts is relevant. Such technologies include electro-contact surfacing. One of the reasons that constrains the widespread use of the method of electrocontact surfacing is the low stability of the electrode roller. Currently, little research has been conducted to study the wear of the electrode rollers and increase their wear resistance. The research on search of ways of increase of durability of rollers-electrodes at electrocontact surfacing is carried out. The operating conditions of the electrode rollers and their operation, the strength of the welded joint when using a tool with different degrees of operation were considered. The operation of the roller-electrode during electro-contact surfacing has a negative effect on the strength of the welded joint of the metal coating with the base due to the reduction of deformation of the filler wire. The results of tests for operation show that a significant reduction in the quality of the welded joint occurs when using electrodes made of hot-rolled copper after 1.5...2 hours of operation. It is not possible to fully compensate for the negative impact of the electrode operation on the quality of the welded joint by adjusting the technological modes of surfacing. This indicates the need for 2 - 3 times the replacement of such tools, after grooving their working surfaces on a lathe. Developed recommendations for the choice of sizes of rollers-electrodes used in electro-contact surfacing of parts of mobile agricultural and transport equipment.