Vol 38, No 1 (2018)

A new approach is proposed to the geometric synthesis of noncircular gears for a rotary hydraulic machine. The corresponding procedure employs universally available mathematical software and standard graphics programs.

The influence of the energy accumulated in the capacitive ignition system and the spark frequency on the life of semiconductor spark igniters in gas-turbine engines is investigated.

The active safety system of a wheeled-walking excavator with automated control of the suspension is considered, in terms of optimization of the base of support (support polygon). Simulation permits assessment of the excavator’s static and dynamic stability.

The selection of optimal heat-treat conditions for nickel–chromium–silicon bronze wire used in the production of helical compression springs is considered. In experiments, the microstructure of samples after aging at 440–480°C is investigated. Tensile tests are conducted.

Analysis of the patent for a wear-resistant knuckle bend in a gas–oil pipeline shows that one of the claims presented there is incorrect. Theoretically, it is established that the introduction of a protective vane within the knuckle bend improves the gas dynamics close to the problematic wear zone at its wall. Manufacture of the vane from steel strip by complex deformation is shown to be economically viable.

The requirements on preproduction and the control software for various digital machining systems (numerically controlled machine tools, robot manipulators, additive manufacturing equipment) in flexible production are considered. By analysis of existing programming languages for digital equipment, UNCL (Uniform Numeric Control Language) has been developed for standard representation of control commands. The use of UNCL in verifying program operation on a machining simulator is considered. Software for the translation of control programs (specified in CLDATA formats and in ISO code) to the invariant format of the universal language is described. The postprocessing of control software from the universal language into programs in commonly used digital control systems is also considered.

Cyclic nitriding characterized by uniform alternation of cycles with high and low nitrogen potential is considered. In the active stage of the process, the surface layer of the steel is saturated with nitrogen, forming a nitride zone. In the passive stage, the nitrides are resorbed and the internal nitriding zone expands. The phase composition of the nitrided layer in У8 and ХВГ tool steels may be regulated so as to increase the wear resistance of the steel and form a smooth hardness gradient over the surface layer. The length of the active and passive stages such that the wear resistance of the steel is 2.5 times greater than in traditional nitriding by ammonia is determined.

New hydraulic filters and equipment for wastewater treatment are reviewed. Basic trends are identified in the development of such systems for wastewater from machine-tool and auto plants.