Vol 38, No 12 (2018)

The elastic and damping properties of a magnetorheological coupling used in the diesel-generator system of portable power sources are considered. The finite-element method is used to assess the maximum shear deformation of a rotor shaft in a tractional generator.

The use of transverse burnishing by means of flat plates for combined finishing and strengthening of cylindrical parts is considered. The influence of the compressive strain and the total number of workpiece rotations on the surface roughness is determined experimentally.

A method is proposed for analytical determination of the normal machining force in grinding by elastic abrasive wheels. The method takes into account that abrasive wheels with elastoviscous properties cannot completely recover their shape within a single rotation.

The benefits and applications of high-strength titanium alloys are considered. Promising avenues for the development of new alloys of this type are noted.

Energy analysis of the wear of machine parts in mixed lubrication indicates that whether the components of the frictional pair seize together depends on the load, the slip rate, the temperature of the frictional surfaces, the temperature surges, the surface energy, the distribution coefficients of the heat flux, and the external overlap.

The creation of general-purpose gear systems with hardened Novikov gears of relatively low precision is considered. By solving three-dimensional elastic-contact problems and modeling, the replacement of expensive high-precision involute gears in the final stage of general-purpose gear systems by less expensive hardened Novikov gears of lower precision is shown to be expedient. Preliminary calculations of prospective high-precision Novikov gears are presented. They offer considerable advantages over their involute counterparts.

The tribological properties in the lining–guide pair of a multidisc braking mechanism are investigated. Samples of 10Kh18N9BL and 38KhA steel with and without hardened surfaces are tested.

Coating formation over the surface of a highly porous material on the basis of activated carbon fiber is considered. The coating is applied from a colloidal solution of metals, with the goal of producing electrodes and composite polymer structures. Experiments show that porous carbon materials may be metallized by means of metal nanoclusters (measuring 2–10 nm) on the basis of electrophoresis, without loss of the initial porosity.

The high corrosion rates of molds in injection molding machines are analyzed. The causes of such corrosion are considered.

Standard operating conditions of ball end mills are considered. A set of surfaces whose machining simulates the production of complex curved shapes is formulated. Surfaces for duration tests of the spherical part of ball end mills are selected.

A shaping method is proposed for cutting a trapezoidal thread on a spindle shaft. This method offers the possibility of using cutters with the same profile in cutting threads of different inclination, depending on the corresponding tolerances.

The practicality of three armature designs for tractional electric motors (power 560–755 kW, tractional force 5326 kgf) is analyzed. The use of an armature shaft of variable (reinforced) cross section in place of the armature with a sleeve is proposed, and suggestions are made regarding the assembly of the bearings. Reinforcement of the working shaft by smoothing may be recommended.

Equations of dynamic lathe processes in autocorrelation-function form are considered. The margin of stability of the dynamic system is calculated on the basis of experimental data regarding the selection of the cutting conditions.

T-700 (Toray) and UMT 45-12K-EP (Umatex) carbon fibers and resin-impregnated reinforcing fabrics (prepregs) based on them are investigated by thermogravimetric analysis and differential scanning calorimetry. By thermogravimetric analysis of carbon fibers from different manufacturers and prepregs prepared with different time–temperature profiles, the content of volatiles is determined, along with possible prepreg structures and the content of carbon fibers. The influence of carbon fibers from different manufacturers on the characteristic temperatures of the epoxy binder and the binder content in the prepreg is assessed. Thermogravimetric analysis shows that, for UMT 45-12K-EP carbon fibers, the content of oxygen-bearing surface complexes is higher than for T-700 carbon fibers. In the prepreg based on T-700 carbon fibers, the content of epoxy binder is about 35%, which is 4–5% higher than for prepregs based on UMT 45-12K-EP carbon fibers. That indicates different wettability of the fibers from different manufacturers.

Stages in the automation of parameter calculations within automatic control systems for industrial processes are outlined. An informational relational model of the cutting conditions in turning is developed. A method is proposed for calculating the level of automation. The role of informational models in the automation of process-parameter calculations is demonstrated.

Globally, manufacturers make great efforts to maintain the performance of industrial equipment. Developers and researchers are interested in automated approaches to maintaining the performance of equipment, especially at enterprises with high degrees of computerization and comprehensive information systems. In the present work, a new approach is outlined: an autonomous control system for maintaining the condition of metal-cutting machines. This approach is based on prior work in the field and permits maintenance on the basis of autonomous control of the state of machine tools. The structure of a system with the following generalized control functions is presented: decision making; and the issuing of commands on the basis of built-in resources. The formulation of control decisions employs the theory of fuzzy sets and fuzzy logic. By means of the ANFIS fuzzy network system, the autonomy of state control of the machine tool may be assessed. Criticality assessment of the condition of machine tools and their components is important in making decisions as to the setup of systems controlling the condition of equipment at enterprises, with assessment of their efficiency. In the monitoring subsystem, provision is made for assessment of the diagnostic results, prediction, and the generation of control decisions so as to prevent disruptions of machine-tool operation.

The influence of cutting on the surface roughness and undulation of AMg2 aluminum alloy with regular and ultrafine grain structure is considered. The quantitative influence of profile filters on its surface roughness and undulation is established, on the basis of 2D parameters. In the machining of materials with ultrafine grain structure, the surface quality is better than for materials with regular grain structure.

Assessment of thermal phenomena in the drilling of laminates is critical in printed-circuit production. A quasi-determinate model permits calculation of the expected temperature in the cutting zone during the drilling of small mounting sockets and pass-through holes, with consequent decrease in manufacturing waste.

Means of increasing the reliability and durability of hydraulic cylinders for airplane engines are considered. The wear of their working surfaces may be decreased by applying a carbide–oxide coating and subsequent smoothing.