Friction Machine Research Articles

Laered composite hydrogenated films of zirconium and niobium: method of production and control of properties by thermopower method

In this work, to obtain layered materials with the inclusion of hydrogen, Nb/Zr films with different numbers of layers from 50 to 100 were used. The films were sputtered onto a silicon substrate using the vacuum-magnetron method in a specialized installation. The film thickness was varied from 10 to 50 nm. The resulting material was hydrogenated with protons on a TPU electrostatic generator with an energy of up to 1,2 MeV. The optimal modes for deposition of nano-sized metal multilayer Zr/Nb systems have been determined: for a Zr target, the specific power of the sputtering system is 37,9 W/cm2, for a Nb target — 26,4 W/cm2. A coating with clear boundaries between the individual layers of zirconium and niobium was obtained. It is shown that the optimal modes for studying nano-sized Zr/Nb layers are pressure 700 Pa, power 40 W, frequency 2 kHz, plasma fill factor 12,5 % for coatings with a thickness of individual layers of 100 nm. For coatings with individual layer thicknesses from 10 to 50 nm, the optimal pressure is 650 Pa, power 40 W, frequency 1 kHz. To control properties, the thermopower method is used. It was revealed that after proton irradiation there is an intensive accumulation of hydrogen atoms near the interfaces, which entails a change in the thermopower up to an inversion of its sign. The hydrogen distribution is predominantly bimodal, with local maxima in hydrogen concentration observed at the Nb/Zr interface, and the accumulation at the Zr/Nb interface is significantly lower. Hydrogen localization near the interfaces occurs predominantly in the vicinity of zirconium.

Enhanced Electrical Output in an Electrostatic Generator Using Charged Water

Enhanced Electrical Output in an Electrostatic Generator Using Charged Water

Advantages of a novel truncated cone DE-air generator in energy conversion

Abstract Harvesting energy from ambient environments such as vibrations is a feasible approach to selfpower low powered electric devices. T- he dielectric elastomer generator (DEG) is a type of novel electrostatic generator with superior vibration energy harvesting (EH) performance. On the basis of traditional DEGs, a new concept of dielectric elastomer (DE)-air generator (DEAG), which contains the air layer and the DE membrane (DEM) as a composite dielectric layer, is proposed in this paper for the first time. Inspired by a classical truncated cone DEG (TC-DEG) concept, the novel truncated cone DEAG (TC-DEAG) is designed and comprehensively studied. Compared with the TC-DEG, the proposed TC-DEAG provides the larger capacitance ratio, leading to superior electrical output. The energy conversion mechanisms of both the TC-DEG and the TC-DEAG under a regular linear reciprocating excitation are analyzed theoretically by deducing the deformation condition of the DEM and the electrical outputs. Through measuring the capacitance of the DEM under deformations and testing the output voltage of the fabricated generators, the proposed theoretical models and predictions are verified. Moreover, numerical simulations based on the verified theoretical model are conducted to reveal the influences of some important system parameters on the EH performances of both generators, providing guidelines for the performance improvement of the generators.

Nature in Seclusion. The Monastic Republic of Letters in Southern Germany.

Monasteries were famous for their extensive libraries and richly decorated churches. Less well known are their observatories and their mathematical-physical collections with telescopes, air pumps, and friction machines. But how did the way of life in the monastery and scientific practices influence each other? This paper examines the interaction of scientific practices and religious way of life using the example of southern German monasteries in the second half of the eighteenth century. It shows how the monks pragmatically linked monastic life and research practice, thereby forming their own specific scientific culture. This closes an important gap in the understanding of scholarship in the eighteenth century by foregrounding the monasteries as places of knowledge production, which have so far received little attention alongside universities and academies.

On the effectiveness of using carbamide-based salt baths for low-temperature cyanidation of improved carbon and alloy steels

Purpose. A study of cyanidation of improved carbon and alloy steels of grades 30, 30HGT, 30H13 at a temperature of 550–580 °C was carried out in baths based on carbamide and sodium carbonate. Recommendations on the use of these baths for surface hardening of carbon and alloyed improved steels used for the manufacture of machine parts are formulated. Methods. The microstructure of the diffusion layer of steels on transverse sections was studied using a Quanta FEG – 650 electron scanning microscope with an EBCD focused ion beam microanalysis system. Cyanide wear tests were performed under friction conditions analogous to those of die tools. The wear resistance of the carbonitrided samples was investigated on a SMTs-2 friction machine. The tests were performed under both dry friction and boundary friction conditions. Results. The high efficiency of the proposed bath composition at a given temperature has been experimentally shown. As a result of cyanidation, modified layers saturated with solid inclusions (ε-phases) are formed on the surface of steels, characterized by high hardness, low coefficient of friction and high wear resistance. Conclusion. According to the results of the conducted research, it can be concluded that low-temperature cyanidation of improved steels of various grades can be carried out in cyanide-free salt baths. The optimal composition of the cyanide bath is 40% carbamide (NH2)2CO; 40 % soda ash Na2CO3 and 20 % NaCl table salt. The proposed bath does not contain toxic and scarce components, therefore it is environmentally safe and very cheap and can be used with great effect in machine-building, repair and tool industries.

ТРИБОТЕХНИЧЕСКИЕ ИССЛЕДОВАНИЯ ВТОРИЧНЫХ БРОНЗОВЫХ ПОКРЫТИЙ

One of the features of agricultural machines is the use of a sufficiently large number of parts made of non-ferrous metals and alloys in their designs, since they have high antifriction properties, corrosion resistance, withstand significant specific loads and high speed conditions. Most often these are bronze plain bearings of the bushing type. Tribotechnical studies of coated samples based on secondary composite materials on a friction machine is an important direction in the development of technologies for the restoration and hardening of bronze parts and assemblies. Secondary composite materials are obtained from production waste by the electroerosion dispersion, which allows to reduce production costs and reduce the environmental burden. Such powders can be used to create repair coatings with high wear resistance. (Research purpose) The research purpose is performing a comparative analysis of the tribotechnical properties of coatings obtained usng secondary composite materials and electric spark processing. (Materials and methods) Samples with bronze coatings were produced for research. Conducted tests on the friction machine II5018. (Results and discussion) It was determined that coated samples based on secondary composite materials have higher wear resistance and less friction compared to uncoated samples. It was found that with increasing load and sliding speed, the difference in wear resistance and friction between coated and uncoated samples increases. The coating based on secondary composite materials is especially effective in conditions of high loads and sliding speeds. (Conclusions) Comparative tribotechnical studies of coated samples based on secondary composite materials have shown that such coatings can be an effective way to increase wear resistance and reduce friction in various machine components.

Study on the electrostatic shedding and crushing characteristics of ethanol and diesel droplets

The study of electrostatic shedding and crushing characteristics of droplets is the basis of understanding electrostatic atomization, and the study of its shedding and crushing behavior in electrostatic field is conducted. Micropump drive is used to control the flow rate, electrostatic generation device to form a stable electric field, light lighting and high-speed camera to obtain the dynamic behavior of shedding and crushing process, and use digital image processing technology to extract the process parameters. The results show that: when the capillary tube diameter and flow are unchanged, when the electric field voltage is low, the droplet deviates and falls off, the diesel droplet is smaller than the ethanol; when the electric field voltage is moderate, the droplet is closed or deformed into wave strip; only when the flow rate increases and the electric field voltage is large, the average particle size of ethanol is smaller than diesel, indicating that the electrostatic atomization effect of ethanol with small surface tension is significantly better than that of diesel oil.

Development of Environmental Monitoring Sensor for Steel Corrosion in Concrete based on Micro-Electro-Mechanical Systems (MEMS)

Many bridges located near marine environments usually have high risk to lose their structural performance due to corrosion of reinforcing bars with chloride attack. While a huge amount of budget to maintain may be consumed for the structural maintenance methodologies, an efficient monitoring system for Reinforced Concrete (RC) structures in the corrosive environment is strongly demanded. Thus, structural health monitoring in real situations is significant for bridge asset management. The alternative way for preventing severe damage propagation is proactively monitoring the environmental condition containing chloride ion and its effect on the durability of concrete structures, for which numerous methods have been conventionally suggested such as dry gauze method to capture chlorides in air. In this study, Micro Energy Harvester (MEH) based on Micro-Electro-Mechanical Systems (MEMS) is technically applied to develop a sensor to identify the corrosion environment with chlorides in the exposure condition. MEMS is a rapidly evolving device, which enables to monitor the changes in natural frequency and amplitude at nodal locations of the targeting structure due to vibration-based electrostatic power generation induced by the corrosive environment. The purpose of this research is to develop a system for detecting the high corrosion-prone areas and finding the suitable metal sheet material for various chloride ion conditions, using the metal sheet as a cantilever structure for the MEMS device. 4 types of metal, aluminium, copper, iron and zinc are considered for the parametric experiments. Several scenarios are considered including chloride ion concentration, temperatures, and wet and dry conditions to compare the dominant frequency changes of each metal sheet and determine their sensitivity to corrosion environment. From the preliminary results, iron and zinc have a significant drop in frequency with the elapsed exposure period, which indicates that they are highly sensitive to the external chloride ion environment. These results offer an innovative and proactive approach to structural health monitoring for further developed applications. It enables prompt maintenance and early detection of potential issues for corrosion of steel bars in concrete, ensuring the longevity and safety of RC bridge structures.

Emle-engine: A Flexible Electrostatic Machine Learning Embedding Package for Multiscale Molecular Dynamics Simulations.

We present in this work the emle-engine package (https://github.com/chemle/emle-engine)─the implementation of a new machine learning embedding scheme for hybrid machine learning potential/molecular-mechanics (ML/MM) dynamics simulations. The package is based on an embedding scheme that uses a physics-based model of the electronic density and induction with a handful of tunable parameters derived from in vacuo properties of the subsystem to be embedded. This scheme is completely independent of the in vacuo potential and requires only the positions of the atoms of the machine learning subsystem and the positions and partial charges of the molecular mechanics environment. These characteristics allow emle-engine to be employed in existing QM/MM software. We demonstrate that the implemented electrostatic machine learning embedding scheme (named EMLE) is stable in enhanced sampling molecular dynamics simulations. Through the calculation of free energy surfaces of alanine dipeptide in water with two different ML options for the in vacuo potential and three embedding models, we test the performance of EMLE. When compared to the reference DFT/MM surface, the EMLE embedding is clearly superior to the MM one based on fixed partial charges. The configurational dependence of the electronic density and the inclusion of the induction energy introduced by the EMLE model leads to a systematic reduction in the average error of the free energy surface when compared to MM embedding. By enabling the usage of EMLE embedding in practical ML/MM simulations, emle-engine will make it possible to accurately model systems and processes that feature significant variations in the charge distribution of the ML subsystem and/or the interacting environment.

Mesomorphism and Tribotechnical Characteristics of Lubricant Compositions with Mesogenic Additives Carboxylates Cu(II)

The purpose of the work is to characterize the lubricants based on Llitol-24 and synthetic solidol with additives copper(II) carboxylates when using them in friction nodes in loading conditions and temperature. The lubricant compositions with additives copper(II) carboxylates based on synthetic solidol and Litol-24 form the columnar mesophases depending on thermodynamical conditions and concentration of additives.Methods. We study the lubricant compositions with dielectric spectroscopy and и polarization light microscopy. The studies lubricant compositions are tested on the frictional machines by preceding authors, which performed their synthesis and numerical estimations for their geometry parameters. It is shown, that the columnar mesophase formed by the compositions with copper(II) carboxylates simulates favourable tribological conditions for lubrication (reduction of the friction coefficient at the appointed range of additive concentrations and reduction of wear) and unlike to crystalline phases, shows orientation effects at the surface of interacting surfaces of machine elements and devices. These factsmotivate the study of influence of physicochemical properties and composition on mesomorphism of considered lubricant compositions.Results. In our measurements, we found the main dielectric characteristics of two kinds of the lubricant compositions: dielectric constant and dielectric loss, electroconductivity, dissipation factor, the Arrhenius functions are plotted, and the activation energies of the lubricant compositions we study are calculated. The microphotogram for textures of the lubricant compositions depending on temperature and concentrations are received. The differences in mesomorphic properties of the lubricant compositions with additives Cu(II) valerate and isovalerate are confirmed.The conclusion of the work is that the composition of the lubricant is optimized by the choice of additive concentration, the length of the mesogenic chain of the copper(II) carboxylate molecule and its conformation.

Effect and performance analysis of different surface treatments on polymer-metal friction pairs

The reliability of machinery can be directly impacted by severe wear and failure of joint bearings, particularly under harsh operating conditions or after prolonged use. The study aimed to investigate the impact of various surface treatments on the properties of materials using a disc-disc contact friction machine to simulate working conditions similar to those experienced by joint bearings. The application of chrome plating resulted in a significant enhancement in performance, leading to a 20% reduction in the coefficient of friction and an 80% decrease in the wear rate to 0.071 and 1 × 10−5 mm3/(N·m), respectively, at 30 MPa and 42 mm/s. Additionally, it increased the bonding of the transfer film base by 20% compared to untreated specimens, as indicated by nano-scratch tests. On the one hand, the elevated hardness of the chrome-plated coating facilitates uniform load distribution, while on the other hand, the presence of microcracks on the surface aids in retaining a greater amount of abrasive debris and in the formation of a more effective transfer film. Consequently, this diminishes the wear of the polymer material. This discovery has the potential to influence the improvement of surface treatment procedures and the selection of materials for the advancement of engineering practices.

Contactless Electrostatic Piloerection for Haptic Sensations.

In this project, we create artificial piloerection using contactless electrostatics to induce tactile sensations in a contactless way. Firstly, we design various high-voltage generators and evaluate them in terms of their static charge, safety and frequency response with different electrodes as well as grounding strategies. Secondly, a psychophysics user study revealed which parts of the upper body are more sensitive to electrostatic piloerection and what adjectives are associated with them. Finally, we combine an electrostatic generator to produce artificial piloerection on the nape with a head-mounted display, this device provides an augmented virtual experience related to fear. We hope that work encourages designers to explore contactless piloerection for enhancing experiences such as music, short movies, video games, or exhibitions.

Formulation and Antimicrobial studies of Microencapsulated Musanga cecropioides Stem Bark Extract

Microencapsulation is the process of coating small droplets of liquid or solid materials with a continuous film of polymeric substances. The aim of the research was to formulate microparticles of Musanga cecropioides stem bark extract. The dried, powdered stem bark of Musanga cecropioides was extracted by maceration. The aqueous extract was microencapsulated using polymers such as alginate, pectin and hydroxylpropyl methylcellulose acetate succinate (HPMCAS) by counter-ion coacervation method using an electrostatic droplet generator. The formulated microcapsules were evaluated for flow properties, particle size, drug content, antimicrobial activity and in vitro release kinetics in simulated gastric and intestinal fluids. The microparticles were subjected to stability tests under different temperature (45°C, 25°C and 8°C) and relative humidity (100% RH, 78% RH and 0% RH) conditions for a period of three (3) months. The mean particle size of the microcapsules decreased with increasing applied voltage of the electrostatic generator. Particle size range for the batches of formulated microparticles was 68.20-223.84µm. The percentage entrapment efficiency of the batches of microparticles ranged from 80.26-86.58%. The microparticles lost a significant percent of its drug content after storage at different temperature and relative humidity conditions. The formulated microparticles and crude extract possess significant antibacterial action against both gram positive and negative bacteria as well as antifungal effect against C. albicans. Microparticles of M. cecropioides extract were formulated by counter-ion coacervation method using an electrostatic droplet generator which conferred advantages of sustained drug release, reduced frequency of dosing, masked unpalatable taste, improved stability and enhanced patient acceptance on the crude extract.

Study of the effect of macrogeometry of rubbing steel bodies at their point contact on the tribological characteristics of lubricants under boundary lubrication conditions

The effect of the shape of contacting nonconformal elements of friction units that form an initial point contact on the tribological characteristics of lubricants during friction in the boundary lubrication mode. Point contact of rubbing bodies is realized on four-ball friction machines when testing tribological characteristics of lubricants in accordance with Russian GOST 9490–75 and GOST 23.221–84 Standards.However, these tests are carried out with the friction of standard bearing balls and does not allow taking into account the impact of materials of rubbing bodies on the results of the experiment. Therefore, two alternative designs of mandrels were developed, which allow implementation of two friction schemes: «rotating ball clamped in the spindle of the machine – three roller face planes» and «rotating ball — three cylindrical rollers». The load on the friction unit for both friction schemes, as well as in parallel on the mandrel under testing, in which three balls are installed, is the same (108 N), the spindle rotation speed is equal to 1 rpm, duration of testing is 60 min. The diameter of balls used in these experiments was 12.7 mm, and diameters of rollers were 5 and 8 mm, respectively. The material of samples was ShKh-15 tool steel or its 100Cr6 analogue. The designs of mandrels and the dimensions of samples were chosen in such a way that in all cases the contact areas of the experimental samples with the wearing (upper) ball would lie on a circle with a diameter of 7.32 mm. The tests were carried out under dry friction, and in boundary lubricated conditions in a PAO-4 polyalphaolefin oil medium, as well as in the same oil medium with the additives of oleic acid and DF-11 (a solution of zinc dialkyldithiophosphate in a low-viscosity oil). It is shown that the composition of a lubricating medium has a decisive effect on the test results (i.e., on the values of the friction coefficients and on the values of the areas of wear scars), while the geometry of the rubbing bodies, as well as the maximum Hertz stresses in the tribological contact, had a little effect on the antifriction and anti-wear characteristics of oils.

Research on seedling sowing method based on high voltage electrostatic characteristics

In response to the difficult problem of high leakage rate and low seed pick-up rate of traditional air-suction seed dischargers. This study proposes a new high-voltage electrostatic vegetable seedling sowing method and system based on phase sucking of opposite charges and repulsive seeding of same charges. This method does away with small orifices and long conductance suction holes. It can solve the technical bottleneck of the traditional air-suction seed rower at the source, which causes a decrease in seed rowing accuracy due to clogging of the suction holes when facing irregular small vegetable seeds that are not pelleted. Combining high voltage electrostatic polarisation for seed vigour with precision seeding technology. Improving seed vigour and crop yield while precision sowing. Modelling the mechanics of adsorption seeding and repulsive seeding systems. Identify the main factors affecting electrostatic adsorption and phase repulsion forces and their interrelationships; Analysis of the decay mechanism of the electrostatic adsorption force upon repeated action. Proposing measures for the rapid restoration of the original equilibrium state of the dielectric insulation by reverse electric field polarization; Analysis of the migration pattern of electric particles during polarisation. Solving the equations for seed dynamics during sowing; At positive input voltages of 16 kV and negative input voltages of 0, 4, 8, 12, 16 and 20 kV. Separate dielectric insulation layer adsorption seeding tests. The test results show that: The reverse electric field polarisation of the dielectric insulating layer is effective in containing the electrostatic adsorption decay. The best containment was achieved at a positive input voltage of 16 kV and a negative input voltage of 16 kV; Seeding performance verification tests at a positive input voltage of 16 kV and a negative input voltage of 16 kV. The test results show that: The sowing conformity index was 90.25 %, the reseeding index 3.40 % and the missed sowing index 6.35 %. In the evaluation of applied research, the multi-objective optimization design with the objective function of maximum seed discharge qualification index, minimum leakage index and replanting index, the optimal parameter combinations of the test factors can be obtained as follows: the size of the type hole is 5.977 mm, and the output voltage of the positive high-voltage electrostatic generator is 16.423 kV, and at this time, the seeding machine's seed discharge qualification index is 90.78 %, the replanting index is 3.05 %, and the leakage index is 6.17 %. To verify the reliability of the optimal design of structural parameters, the seeding performance verification test is carried out, which can be obtained: the qualified index of row seeding is 90.54 %, the index of reseeding is 2.86 %, and the index of leakage is 6.60 %, which meets the technical requirements of precision seeding. The research not only provides a reference for the development of precision sowing machinery and equipment for irregular small-grain vegetable seeds. It also provides an academic reference for the research of quantitative adsorption and rapid separation methods and theories for irregular small particle materials.

Experimental installation for wear tests of materials and coatings

On the basis of the analysis of existing tribological testing methodologies, which includes the selection of controlled wear parameters, the influence of the type of friction, contact geometry, surface roughness, the scheme of tribological research, the choice of a machine 2168UМТ for friction testing of materials is substantiated. The friction machine allows you to install three samples at the same time, change the pressure in the contact zone in a wide range, control the moment of friction, the rotation frequency of the counterbody, the number of revolutions (friction path), change the rotation frequency, respectively, the sliding speed, automatically limit the distance traveled and other functions. The method of wear is adopted according to the finger-ring scheme, linear wear is monitored using an indicator rack with a value of divisions of the measuring device of 0.001 mm. To fix the samples on the machine caliper, holders were designed and manufactured, which ensure the self-fixation of the sample on the counterbody - a spherical joint made of the rolling body of the bearing. due to the fact that the samples were pressed against the counterbody with a force corresponding to the nominal contact pressure, they were self-aligned. After the sample was self-assembled, the whole structure was fixed by tightening the nuts. The counterbody is made of a rolling bearing ring, the material is steel SHX15, the hardness of the base is HRC 61. Three devices are mounted on the caliper for permanent lubrication of the running track immediately before the approaching sample. Thus, at certain values of pressure and speed, the mode of marginal friction can be reached, which was marked by a low coefficient of friction.

Electrostatic generator enhancements for powering IoT nodes via efficient energy management

Electrostatic generators show great potential for powering widely distributed electronic devices in Internet of Things (IoT) applications. However, a critical issue limiting such generators is their high impedance mismatch when coupled to electronics, which results in very low energy utilization efficiency. Here, we present a high-performance energy management unit (EMU) based on a spark-switch tube and a buck converter with an RF inductor. By optimizing the elements and parameters of the EMU, a maximum direct current output power of 79.2 mW m-2 rps-1 was reached for a rotary electret generator with the EMU, achieving 1.2 times greater power output than without the EMU. Furthermore, the maximum power of the contact-separated triboelectric nanogenerator with an EMU is 1.5 times that without the EMU. This excellent performance is attributed to the various optimizations, including utilizing an ultralow-loss spark-switch tube with a proper breakdown voltage, adding a matched input capacitor to enhance available charge, and incorporating an RF inductor to facilitate the high-speed energy transfer process. Based on this extremely efficient EMU, a compact self-powered wireless temperature sensor node was demonstrated to acquire and transmit data every 3.5 s under a slight wind speed of 0.5 m/s. This work greatly promotes the utilization of electrostatic nanogenerators in practical applications, particularly in IoT nodes.

РАЗРАБОТКА СПЕЧЕННОГО ФРИКЦИОННОГО МАТЕРИАЛА ДЛЯ ГИДРОТРАНСФОРМАТОРА ГМП САМОСВАЛОВ БЕЛАЗ

The torque converter is designed to transmit mechanical energy from the engine through a circulating fluid flow and automatically steplessly changes, within certain limits, the angular speed and transmitted torque depending on the load on the dump truck wheels. The torque converter makes it possible to achieve low speeds of the dump truck with increased traction on the drive wheels, ensures stable engine operation when the load changes, and also helps reduce dynamic loads in the dump truck transmission. The paper presents the results of a study of the effect of iron-chromium alloy powder ПХ30 (PKh30) on increasing the performance properties of sintered friction material for use in the torque converter locking clutch of a hydromechanical transmission. This is achieved due to the high physical and mechanical properties of PKh30, and the Cr23C6 layer formed during the sintering process with a thickness of up to 6 μm. It is established that the introduction of 10–40 vol.% of PKh30 powder helps to increase the friction coefficient from 0.042 to 0.075, with the maximum content being 28 %. Based on the data obtained, the composition of the composite friction material ФМ-15 (FM-15) was developed and patented. The manufactured friction discs, installed and operated in the hydromechanical transmission torque converter of the BELAZ-7555E mining dump truck with a load capacity of 60 tons, showed high performance properties. The developed composition of the friction material is also used in the friction clutches of the loading and hauling machine MoAZ-40751 with a load capacity of 16 tons and the loading and transport mine machine MoAZ-75851 with a load capacity of 50 tons with an electronic-hydraulic automatic control system. The study of tribological properties was carried out on a friction machine ИМ 58 (IM 58). The morphology of the friction surface was studied on a scanning electron microscope MIRA (Czech Republic) with an INCA 350 micro-X-ray spectral attachment from Oxford Instruments (United Kingdom). Phase composition was determined on an Ultima IV X-ray diffractometer of Rigaku Company (Japan) in CuKα radiation at an X-ray tube voltage of 40 kV, anode current of 40 mA.

Determination of tribotechnical properties of polymers depending on the test conditions

The paper presents the results of morphological and tribotechnical tests of samples of ultrahigh molecular weight polyethylene (UHMWPE), high molecular weight polyethylene (HMWPE), polyethylene terephthalate (PET), polyoxymethylene (POM). Tribotechnical tests were carried out on a friction machine with a vertical axis of rotation of the spindle according to the scheme: “the end of the annular surface of the counter–flange sleeve (steel 40Kh, 48-52 HRC) is a plane (wide side of the polymer sample).” The moment of friction and the load on the samples were determined using strain gauges placed in the friction machine in continuous mode. The effect of the surface roughness of a 40Kh steel counter-tile on the friction coefficients when tested without lubricant and in the presence of hydraulic oil MGE-10A at a constant sliding speed has been established. The maximum values of the friction coefficients were obtained during friction without lubrication after processing the end face of the counter-tile with sandpaper P180 and P1200. The minimum values of the friction coefficients were obtained by lubricating MGE-10A after processing with sandpaper P1200 of a 40Kh steel counterplate. According to the morphology of the friction surfaces, the main wear mechanisms for UHMWPE, micro-cutting, HWMPE and PET, micro-cutting and plowing and for POM, fatigue wear and plowing are determined.

Hardening of gear teeth depending on the concentration of abrasive particles in the transmission oil

The article deals with the issues of determining the life and limiting concentration of abrasive particles in the oil of transmission units, depending on the type of hardening of gear teeth. Resource was determined after volume hardening, hardening by current of high frequency and cementation by hardness of gears materials, on the friction machine on the samples which have been made of gears material, working in oil with abrasive particles, considering coefficient of acceleration at test. Maximum allowable concentration of abrasive particles in machine oil, were estimated on the basis of expression for calculation of wear rate, providing the set life, maximum allowable wear depending on modulus of gearing, hardness of gearing material, size of abrasive particles, geometrical and kinematic parameters of gearing.