The publication is devoted to the study of the quality of the hydraulic system with four series-connected hydraulic motors. These hydraulic systems can be used to drive the working bodies of agricultural machines, have significant advantages in their layout, but at the same time and disadvantages, the elimination of which requires a detailed study of the processes occurring during the operation of this type of system. The analysis of the previous works of scientists in this area allows us to conclude that it is possible to conduct theoretical research in this direction. A mathematical model of the proposed hydraulic system has been developed, which takes into account the effect of external load on the shafts of hydraulic motors, the inertia of the system, the effect of leaks from the connections of the elements of the hydraulic system and possible overflows of the working fluid from the high-pressure zone to the low-pressure zone. At this stage, wave processes occurring in the cavities of the hydraulic system were not taken into account. The solution of the resulting system of differential equations was carried out using the Runge-Kutta-Feldberg method with automatic change of the integration step in the mathematical package MathCad. The resulting transient processes were analyzed for the amplitude of pressure surges and the frequency of its change. Carrying out this analysis allows you to obtain comprehensive information about the nature of transient processes in the hydraulic system in order to find such a ratio of design and technological parameters, in which the system under study met the requirements regarding the quality of work as part of a technological machine. During the research, special attention was paid to the processes occurring at the moment of starting the hydraulic system, and the moment of application of the technological load.

Methods of theoretical solution of problems in the processing of metals by pressure are insufficiently developed for practical use in the development and implementation of new technologies and improvement of existing ones. To meet the stringent requirements for the accuracy of determining the stress-strain state, it is necessary to have reliable information about the evolution of the development of the plastic deformation process at each point of the metal from the very beginning of the deformation. This will allow to obtain with high accuracy the important characteristics of the technological heredity of the products that they acquire as a result of their plastic processing. The first and important step in the calculations of the stress-strain state is to obtain the kinematic characteristics of the plastic flow of metal in the form of analytical dependences, which will formulate the patterns of deformation in the technological processes of metal forming. The article considers the possibility of applying the method of current functions to determine the components of the strain rate tensor in established stationary processes of plastic deformation. It is assumed that in the case of axisymmetric plastic deformation of a metal in a channel with curvilinear boundaries, the kinematics of the process is similar to a plane flow. In obtaining the equations, the differential equation of current lines taking into account the incompressibility condition was used to determine the components of the strain rate tensor. To explain the physical meaning of the current functions, two infinitely close current lines were considered in the flow plane, and an expression was obtained for the flow through a finite transverse current tube. In the absence of radial velocity components at the boundaries, constraints are obtained that are imposed on derivatives of current functions at these boundaries. The developed method of calculating the kinematic characteristics of plastic deformation for established axisymmetric stationary processes will simplify the mathematical processing of the obtained results and increase the reliability of the determination of the stress-strain state.

The article shows the results of the study of the velocity of the sprayed powder particles on the example of cold gas-dynamic spraying of copper powder C01-11. Features and advantages of gas-dynamic spraying before other gas-thermal coating methods are given. The importance of the speed regime of coating and its influence on the formation of the coating is analyzed. A computational experimental method for determining the velocity of sprayed particles is proposed, as well as an experimental setup with the help of which it is possible to obtain objective data on the velocity regime of cold gas-dynamic coating. The design of the applied gas-dynamic spraying device is shown, which contains an electric heater of the compressed air flow and an accelerator of the heated compressed air into which the sprayed metal powder is driven due to the ejection effect. An experimental setup was used for the study, which contained two rotating disks mounted at a distance of 20 mm from each other on the shaft of a high-speed electric motor, with holes in the upper disk through which spraying occurs on the surface of the lower disk. Due to the fact that the disks with the spraying process rotate at a speed of 10587 rpm is the displacement of the sputtering figure on the lower disk relative to the projection of the hole of the upper disk on the lower disk. The magnitude of this displacement is calculated by the velocity of the particles of the sprayed powder, according to the above method. The parameters that are taken into account when calculating the speed of the spray particles of the powder is the diameter of the nozzle of the spray device 5 mm. The distance from the nozzle cut to the upper disk is 10 mm. The distance from the nozzle cut to the lower disk is 32 mm. The distance between the disks a = 22 mm. The radius on which the nozzle of the spray device is installed is 90 mm. As a result of the experiments, it was found that when spraying copper powder C01-11 at a temperature of 20 ºC, the spraying speed is 232.2 m / s, which does not provide conditions for coating, and at elevated temperatures to 285 ºC quality coating was formed. The spraying speed was from 302.7 to 359.2 m / s for critical sections of 2.5 and 3.01 mm2, and the spraying area at higher speeds was approximately 20% higher than at lower speeds. This makes it possible for researchers to determine the velocity modes of spraying and, accordingly, to more accurately assign the optimal technological parameters to achieve the highest quality results of creating functional coatings.