Vol 39, No 12 (2019)

A device is developed for removing the supercharger impeller from the conical shaft of the pump in a major gas pipeline. The working force of the tool is 400 kN, and free motion of the shaft over 6 mm is possible. The tool’s drive consists of three tubular elements in which reversible memory is initiated on compression. The calculation is based on thermomechanical diagrams.

A method is proposed for adjusting the regulators of dynamic quadratic systems in which the state variables influence one another, with retardation of the kinematic deviations from the reference (program) trajectory, in the case where the parameters are integrally indeterminate. This approach is based on decomposition of the initial system and the direct Lyapunov method.

The temperature resistance of Russian vacuum lubricants is studied. The antifrictional properties of lubricants based on perfluoropolyethers are found to be similar: they ensure a low frictional coefficient at 30–300°C. The thermal stability is best for Amethyst and Nika lubricants.

A method for decreasing the mass and cost of auto bodies (frames) in off-road vehicles is proposed. This approach is based on topological, parametric, and multivariant optimization of the body components, their thickness, and the materials employed. As an example, a digital twin is developed for the body of an off-road SUV. In optimization, the constraints on the local and total rigidity and strength are taken into account, as well as the requirements for collision safety.

The intermediate layer formed when diamond is in contact with metals that are active with respect to carbon—such as iron and titanium—is investigated in a vacuum furnace. The conditions in the furnace match those employed in sintering with copper impregnation of the hard-alloy matrix of diamond tools. The results may be used in developing compositions and technologies such that tool materials based on tungsten–cobalt hard-alloy powder have a high diamond content in the matrix.

Attention focuses on the selection of a removable polyhedral insert with recommended geometry of the cutting element, when the tool material meets the requirements of intermittent cutting. Shaping of the cutter’s front surface to intensify machining is also considered.

The use of boundary and volume finite elements in contact problems permits determination of the influence function for bodies of any specific form, with elimination of the indeterminacy at the point of load application; and direct construction of the system of equations for determining the contact regions and the corresponding contact-stress distribution, without the need for complex transformations and without loss of physical significance. As an illustration, the proposed method is used to solve a contact problem.

Modification of the design method for smart production systems is considered. A new classification of decision-making systems is proposed, by morphological analysis of the system’s environment. The primary levels of intellectual capacity of these systems are determined.

The accuracy of robot motion over circular trajectories in milling is analyzed. The milling motion is compared for a robot with precision two-motor servo drives tracking the position of manipulator links; and a robot with traditional gear drives tracking the position of the motor shaft. Computer modeling indicates that it is expedient to use precision two-motor drives in robots for milling and other operations that require highly accurate motion.

A method is outlined for correcting bulk geometric errors of multicoordinate CNC equipment (machine tools, measuring machines, and instruments). In the present work, familiar methods of measuring the volume error are adapted for conditions in which load is applied to the object. As an example, experimental results are presented for the correction of the three-dimensional accuracy of the machine tool in the presence and absence of a load. Migration of the null point in the multicoordinate system under a static load is studied.

The possibility of designing solid ceramic end mills with different geometry is considered. A mathematical model is developed for the cutting section of the mill on the basis of functional relations between the main geometric parameters of a ceramic end mill with a toroidal cutting section. Possible correlations are analyzed among parameters determining tool performance: the shape and size of its helical rake surface, the normal rake angle in its toroidal section, and the strength of the mill. The stress is assessed by finite-element modeling in ANSYS software. The results of finite-element modeling and geometric analysis of the cutting section confirm the need to create a special recess in the toroidal cutting section.

The efficiency of energy conversion and transmission to the cutting zone may be increased by reactive-power compensation, with accompanying resource conservation.