Vol 39, No 6 (2019)

A kinematic model of the gearbox and a simplified kinematic model of a tractor are developed. These models take account of the characteristics of the internal-combustion engine employed, corresponding to the customer requirements on gearbox performance. Virtual tests of the tractor establish the tractional and dynamic characteristics of the tractor and its tractional class according to State Standards GOST 27021–86 and GOST 30745–2001 (ISO 789-9–90).

For the example of the JetCat P-200RX turbojet engine, optimization of the diffuser and straightening unit of a compact centrifugal compressor is considered, on the basis of a mathematical model of viscous turbulent air flow. The goal of optimization is to increase the isentropic (adiabatic) efficiency of the compressor.

Tests with nozzles of different types are conducted in a segment of a combustion chamber. The nozzle associated with the most efficient fuel combustion is identified. Tests of a complete combustion chamber in a gas-turbine engine are recommended.

A new method of assessing the impact–abrasive resistance of steel permits simulation of the impact–abrasive wear with variation in the magnitude and inclination of the impact force, type of abrasive, and its grain size and rate of consumption. The influence of five carbide-forming elements on the properties of the cast and quenched steel is studied: specifically, attention focuses on the abrasion resistance, impact–abrasive resistance, and hardness of the steel. Optimal steel compositions with abrasion resistance and impact–abrasive resistance greater than that of 35GL steel are identified.

A hybrid control system has been developed for an anthropomorphic gripping device capable of grasping an object whose physicomechanical and geometric characteristics are unknown. The surface is identified on the basis of a multiply connected inverse pendulum, simulating the hand of a gripping device. A fuzzy control algorithm is synthesized for a two-level hybrid automatic control system.

In the design of complex objects, modular principles are of great interest. That approach has both negative and positive consequences. It clearly affects the cost of acquiring the required stock of equipment and, in particular, the spare parts necessary for its maintenance. Optimization of the modular structure of industrial equipment may best be approached in economic terms. Smart information systems for the support of management decisions prove very useful. A structure is proposed for such a system. Examples of such optimization in the aviation industry are presented, and practical experience is noted.

The application of Industry 4.0 concepts to the digitization of machine tools is considered. Organizational and technological principles fundamental to new machine-tool properties, including smart and autonomous control, are outlined. The creation of digital images and digital twins of machine tools simulating their internal processes is discussed. The characteristics and behavior of machine tools over the whole life cycle are analyzed.

The structure of a helical drill with a coolant channel leading to the tool groove and the rear surface is considered. SolidWorks/FlowSimulation design software is used for finite-element analysis.

A method is developed for establishing a correlation between the microhardness and macrohardness at different loads. The method is based on comparison of the dimensions of the initial and reconstructed impressions. The diagonal of the initial impression (before elastic recovery) is determined analytically; that of the recovered impression is determined experimentally. It is possible to determine the macrohardness of thin films from microhardness measurements.