The paper considers the main factors affecting the performance of plain bearings of pinion shafts and identifies signs of the visual manifestation of some malfunctions. It has been determined that most of the considered factors cannot be accurately calculated, however, they need to be taken into account when operating the mechanism. The causes of destruction or damage are determined during the repair in order to eliminate detected deviations. Different rates of damage development should be taken into account when choosing diagnostic parameters and developing the structure of a stationary system for monitoring the technical condition. The results can be extended to similar designs of thick-walled babbitt bearings.
The article discusses current issues of the introduction of high technology (among which special attention is paid to the brain–computer interface) in various areas and sectors of the functioning world economies in order to ensure competitive advantages. The basics of the fourth industrial revolution related to its mass introduction into production, the so-called Industry 4.0, are presented. The aspects of the implementation of technological
entrepreneurship, which becomes an integral part of the introduction of high technology in the process of innovative development of the Russian economy, are analysed
Experimental studies of the mechanism of edge forming during magnetic abrasive finishing in a ring channel are performed. A scheme for cutting material at the edge is proposed. It suggests that removal of material at the top of the edge is possible mainly due to the intensified primary flow moving with an angle of attack to the surface being processed. Two main assumptions are made: the movement of the powder particle along the edge does not participate in edge forming; the shape of the edge in a normal section to the theoretical line of the edge in the given point depends on the ratio of the projections of the combined cutting speed to normal and binormal, and is formed as a polygonal line. The polygonal line is the result of the intersection of the trajectories of abrasive particles moving with angles of attack to the surfaces forming the edge. It penetrates in the machined surfaces by an amount that depends on the mechanical properties of the material. A mathematical model of the kinematics of edge forming with loose abrasives has been developed. It is suitable for a comparative analysis of the kinematics of the magnetic abrasive finishing in a ring channel in the conditions of large working gaps and spindle machining.
The problems concerning preparation of rotor impellers in turbine units to the assembly and balancing are considered. The authors give recommendations: fitting of centrifugal compressor impellers on a shaft with minimization of technological imbalances, elimination of the sealing surface runout and vibrational activity of the rotor when passing the first critical frequency can be achieved by: preliminary balancing of impellers on a conical mandrel with provision of the specified parameters of residual imbalances; a diametrically opposite direction of the mandrel mounting surface runout and the impeller sealing surface; diametrically opposite direction of residual rotor imbalance relative to maximum runout of the shaft mounting surface. The authors offer a set of patent-protected technical solutions that ensure precise balancing of the impellers.
The article analyses cases of the relationship between two divisions of the enterprise – the master mechanics service and security department. Considering that 70% of visitors to defense plants are supervised by the master mechanics service, the problems of access and exit for outside specialists are relevant. The author concludes that the security of classified information is undoubtedly necessary and very important, but to solve this problem it is necessary to take into account the current technical level and without formalism and senseless spending of working time, in any case.
A method is proposed for reducing the intensity of dimensional wear of cutting tools by autonomous cooling of the cutting zone with the help of first-order phase transitions (evaporation and melting). In this case, part of the thermal energy is spent on the melting of the working substance and then discharged into the environment. It has been determined that the determination of wear rate as a characteristic of wear is more preferable than determination of flank wear, as this allows a unified approach to the description of the processes of flank and face wear. The conducted experimental studies of the operability of the proposed integrated cooling scheme with studies of dimensional wear confirm a decrease in temperature in the cutting zone and, as a result, dimensional wear of replaceable multifaceted plates.
The article discusses the study of the heat exchanger in the form of vertical wells for domestic heat pump installations using computer simulation. A variant of the model of a ground heat exchanger located in four vertical wells with the possibility of increased heat removal from low energy soil is proposed. A methodology for modeling and studying the operation of a heat exchanger based on COMSOL Multiphysics under conditions of instability of the energy potential of the soil is presented, which corresponds to the features of the operation of domestic heat pump units of small and medium size.
