Journal of Machinery Manufacture and Reliability最新文献

A promising approach to the glue-threaded assembly of automotive bodies that can replace conventional riveting and glue-riveting technologies is described. The results of comparative strength tests of glue-threaded and glue-riveted joints are given for the samples made of carbon fiber and aluminum.

Methods of mathematical planning of a multifactorial experiment and processing of the obtained results are used to study the dependence of the optimization parameter—the size of the ground grain—on the rotor speed and the gap between the rotor and the stator. Based on mathematical calculations, a regression equation was obtained in the form of a first- and second-order polynomial, characterizing the contribution of each factor to the process of grinding grain products in conical-rotor mills.

Wave strain hardening technology has appeared relatively recently and is successfully used in various industries to increase the product durability. Modeling is a necessary part of this technology. The long-term goal is to create combined technologies with wave strain hardening and predicted results. Modeling of combined technologies involves sequential modeling of different processes, implying data exchange while calculating. A successful experience of step-by-step modeling of combined processes is presented, the adequacy of the results of which is confirmed by experimental data.

This article addresses the search for a design solution aimed at improving the labor productivity of operators using next-generation block-type woodworking equipment with six saw modules for producing parquet and edged boards. The nature and characteristics of the saw module’s movement allow for new technical solutions that facilitate the replacement of saw blades of varying lengths without the need to change the correcting masses in the hinged joints. The proposed design and technological solution is particularly relevant for solving the problem of removing the saw blade from the resonance zone of its operational frequency of rotation. The quality, range, thickness variability of the produced timber, and the productivity of the equipment significantly exceed the characteristics of world-class machines with similar functional purposes.

Friction stir welding of metals is discussed. A method for calculating the occurrence of resonance in terms of periods and frequencies of reflected waves is proposed. Examples of calculations are given.

Alloys with shape memory based on TiNi are characterized by maximally high characteristics of shape memory and superelasticity, allowing them to be used as implants for various purposes. The enhanced functional properties of the alloys are attributed not only to their physical nature but also to their microstructure, where it is desirable to have grain sizes in the nanostructured range. A new method for obtaining nanostructures based on plastic deformation accompanied by an electric current is discussed.

The application of electroplastic deformation to form semifinished implants made of the titanium alloy VT6 is considered. It is shown that the use of electroplastic deformation avoids the formation of cracks and increases the strain rate by five times.

A comparative operational testing of the traction-power and controlled operation at the testing ground of JSC Russian Railways was conducted for a 3ES5K series locomotive manufactured in 2021, equipped with axle-by-axle traction control and motor-axial rolling bearings with a locomotive friction activation unit, as well as for a 3ES5K series locomotive with axle-by-axle traction control, without any locomotive friction activation unit (equipped with a standard sand feed). The obtained experimental data are analyzed and systematized, the traction-griping properties of the experimental electric locomotive equipped with a locomotive friction activation unit and the reference electric locomotive without such a unit are compared. Conclusions have been drawn concerning the efficiency of the locomotive friction activation unit under freight traffic conditions in the course of operation at the testing ground at the head of a 7100-е freight train on a section of JSC Russian Railways (even direction).

The potentialities of widespread application of electric transport, and in particular, tricycles, are demonstrated. By the example of a transporting-and-technological vehicle with a capacity of up to 3 kW, the potentiality of using such vehicles in agriculture is presented. The breadth of application attracts increased attention to the real consumer properties, which has required the development of a set of tests to reveal such properties with subsequently testing a real sample of a cargo electric tricycle. With the use of special equipment, the angles of tipping and sliding, the position of the center of mass, the run duration with a single-charged battery, the traction and velocity parameters, as well as the vibration loading of the machine have been determined. The set of studies has confirmed the efficiency and compliance with the declared characteristics of the machine, as well as the potentiality of its safe operation under year-round loading conditions on different surfaces.

The isothermal elastic-hydrodynamic problem of lubrication of a finite-length radial plain bearing with a partial angle of coverage is considered. The bearing deformations are determined by the finite element method. The shaft deformations are determined from the solution of a plane problem of elasticity theory for a cylinder. It is shown that, under conditions of strong deformations, the minimum thickness of the lubricating layer along the angular coordinate changes significantly in the direction of the bearing axis. In this case, the thickness takes a minimum value at the ends. Families of curves are given that allow estimating the minimum thickness of the lubricating layer at the ends of the bearing after solving the plane problem.