Mating Parts Research Articles

A GROUPING METHOD TO MINIMIZE SURPLUS PARTS IN SELECTIVE ASSEMBLY

Selective assembly is an assembly method that can achieve high accurate assembly even from the low level of accuracy of manufacturing parts; however, this always exists surplus parts, especially when the clearance or interference fit requirements vary in a given range. This paper presents a method in place of reducing surplus parts based on shifting the mean dimensional values and then grouping the mating parts based on their dimension tolerance and assembly characteristic. Examination case study of piston-cylinder assembly shows that by implementing this method, the percentage of surplus parts is reduced considerably (from 40.65% and 26.18% to 2.63%) and the clearance variation is minimized in comparison with the traditional ones. This method can be applied to manufacture and assemble products with high accuracy.

Artificial Neural Network Predictive Modelling of Laser Micro-Grooving for Commercial Pure Titanium (CP Ti) Grade 2

Grooving is the process of making a narrow channel on a surface of flat or cylindrical workpiece. Groove is precisely made to parts used in automotive, biomedical, and electronics industries. In automotive industries, groove plays an important role especially on mechanical parts to precisely locate seal (o-ring) to prevent gas/oil leakage between dynamic mating parts. On the other hand, artificial neural network (ANN) has been widely used in developing predictive models of various manufacturing processes to save huge amount of production time and money for industries. Unfortunately, very limited research has been investigated on micro groove quality employing ANN predictive models. Therefore, this research work presents on how the Artificial Neural Network (ANN) predictive model has been established, optimised and utilised to predict the laser micro-grooving quality of commercial pure titanium grade 2 material. A 3KW CO2 laser cutting machine was employed considering laser power, gas pressure, cutting speed, depth of cut and focal distance as the design parameters for modelling. On the other hand, three significant responses namely groove depth, groove width and groove corner radius were investigated. Experimental results were fed to establish the ANN predictive model, which then its parameters were optimized to gain high level prediction accuracy. The predicted results of ANN model presented the mean absolute percentage error for groove depth, groove width and groove corner radius at about 7.29%, 10.93% and 11.96% respectively. The obtained predictive results were found quite promising with the average of mean absolute percentage error (MAPE) for quality predictions which falls between 10 to 15%, concluding the validity of the developed ANN predictive model.

Evaluating different strategies to achieve the highest geometric quality in self-adjusting smart assembly lines

Digital twin-driven productions have opened great opportunities to increase the efficiency and quality of production processes. Smart assembly lines are one of these opportunities in which the effects of geometric variations of the mating parts on the assemblies can be minimized. These assembly lines utilize different techniques, including selective assembly and locator adjustments, to improve the geometric quality. This paper signifies that the achievable improvements through these techniques are highly dependent on the utilized fixture layout for the assembly process. Hence, different design methods and productions that can be followed in a smart assembly line are discussed. Furthermore, different scenarios are applied to two industrial sample cases from the automotive industry. The aptest design strategy for each improvement technique is determined. Moreover, the strategy that can result in the highest geometric quality of assemblies through a smart assembly line is defined. • The smart assembly line improves the quality by optimizing the production parameters. • Selective assembly and individual locator adjustments are employed in the line. • Fixture layout can significantly affect the improvements in a smart assembly line. • Individualized locator adjustment is the superior compensating the variations. • The superior design strategy of each production method is introduced.

Silane-based coating charged with TiO2 NPs for dental implant applications

In modern dentistry, various techniques are being used to enhance longevity of a tooth implant. Among the most attractive solutions to promote the long-term stability of a dental implant, is the application of a protective coating on selected parts of the assembly.In this paper, the use of 3-(glycidyloxypropyl)trimethoxysilane and tetraethyl orthosilicate (GPTMS/TEOS) sol-gel coating containing TiO2 nanoparticles is proposed as a locking agent to improve long-term stability of a dental implant. The concept is based on an approach used in machine industry, i.e. enhancing the frictional engagement between the mating parts and therefore preventing their unintentional loosening.Compared with samples not subjected to surface modification, the proposed coating is effective in terms of improving the anti-loosening properties of the abutment screw. High locking efficacy of the sol-gel film, as well as its anti-wear performance, is achieved by the advantageous mechanical properties of the coating. Compared with a pure GPTMS/TEOS matrix, the incorporation of TiO2 NPs in the polymeric backbone results in an improvement of the resistance to hydrolytic degradation, as well as reduction of hardness and Young modulus of the coating.

Оценка несущей способности клеевых соединений с натягом

The experimental test results of glued-mechanical couplings of shaft — bush made with the use of anaerobic sealants are presented. Quantitative estimations of the surface layer quality of the mating parts were obtained that made possible to estimate values of surface waviness of the shaft and the bush. The methodology of the waviness determination of cylindrical couplings is described. The influence of fit on mechanical strength of the shaft — bush coupling depending on properties of a used anaerobic sealant was established.

WITHDRAWN: Role of surface treatment for enhancing resistance to degradation: An outline

Abstract The service life of machine component working under severe environment is a major issue in the industries. Machine component material continually gets degraded due to friction in mating parts, impingement of sand or dust particles on the surface. Higher temperatures in thermal power plants further escalate the degradation and affect the service life of the critical boiler parts/components, which causes the untimed shutdown. In this paper, some technological aspects are studied, which can be protective measures for degradation. The previous researches reveal that the use of protective coatings, hardfacing, friction stir processing etc. onto the surface of the machine component, improves the resistance to degradation. Improvements in microstructural and mechanical properties are significant factors that affect the life of the working component.

Influence of Laser Power and Scanning Speed on the Formation of Single Tracks Formed by Laser Cladding

One of the well-known methods for increasing wear resistance, especially for friction pairs, is surfacing wear-resistant materials on the working surfaces of mating parts [1, 2, 3]. Less expensive grades of steel can be used as the main material in the manufacture of parts, and the surfacing materials in this case must have increased characteristics: mechanical, corrosion and radiation resistance, heat resistance, wear resistance; good anti-friction properties, i.e. more expensive [4, 5]. This significantly reduces the cost of manufacturing or repairing parts, especially in mass production, since cheap grades of steel are used for their manufacture [5, 6]. Improvement of parts by gas powder laser cladding is carried out in shipbuilding, energy, oil and gas and mining industries, in the aviation industry and others. Note that although the method of coating appeared a long time ago, various methods of applying surfaced coatings are still being developed and refined [5,6]. In gas powder laser cladding, coatings are obtained by forcing the powder flow directly into the laser radiation zone [7, 8]. The powder particles are heated in the laser radiation zone and fall on the treated surface (substrate). It is known that the powder particles melt only after they hit the substrate [3, 4], but at the same time the surface layer of the base metal melts. After heating and melting the substrate, a liquid melt bath is formed, which, along with the molten powder, contains a significant part of the base metal components [7, 8]. The intensity of saturation of the surfacing metal with the substrate components is characterized by the proportion of the base metal in the cross section of the track, which is determined by the mixing ratio [9, 10, 11]. It is equal to the ratio of the area of the melted substrate to the sum of the areas of the melted substrate and the track as a percentage and depends on the cladding modes, which is determined after metallographic studies of the structure of protective coatings [8].

Triad model: simulation - functional tensometry - information database in the assessment of the reliability of technological machines

The concept of a multidisciplinary approach to assessing the resource of individual components of the machine by combining database information based on simulation techniques and functional tensomethration is proposed. Simulations determine the reperative points of the tendometric sensors. The creation of a diagnostic model using basic concepts of information theory has allowed the development of a synergistic model for the recognition of the area of displacement of areas of uncertainty, which will ensure the identification of the defect (risk-denial). The formation of an electronic database of parametric data on the nature of loads as a diagnostic indicator of the change in the accuracy of pairing in machine systems is justified. Experimental studies were conducted on the model of the quick-capler. Hierarchical structuring of the machine to the level of mating parts with digital control of the criticality of the magnitude of external and internal loads ensures reliability control throughout the entire service life of the machine. When disposing of machines, this data allows you to obtain information about the residual resources of the elements for their reuse or the feasibility of restoration. This, in turn, will ensure the environmental friendliness and economy of the process.

Optimization of the parameters of a partially regular microrelief by vibration rolling method

Experience of operating machines shows that their quality depends on the nature of the contact of mating parts. The irregular nature of the surface microrelief, which is due to traditional treatment methods used, arises difficulties in solving three main problems of microgeometry optimization: reliable, theoretically substantiated normalization, technological support, accurate measurement and control. This determined the direction in solving the problem of increasing the accuracy and reliability of the surface quality normalization, that is the microrelief normalization. At present, there are a large number of technological methods for surface treatment aimed to form a regular microrelief on it. One of the most common and studied methods for the regular microrelief formation is the vibration rolling method based on thin plastic deformation of the surface metal layers and a complex relative displacement of the treated surface and the deforming element. Significant progress in the surface quality normalization was achieved after the introduction of GOST 24773-81, the standard for regular microreliefs. For example, the nomenclature of parameters and characteristics of partially regular microreliefs includes the relative area occupied by regular inhomogeneities FH. FH is a value expressed as a percentage of the area occupied by regular inhomogeneities to the area of the treated surface. If FH is determined for the 2A·Sk area within the boundaries of a microrelief element at different axial steps of regular inhomogeneities, the microgeometry of a partially regular microrelief can be described ambiguously. To avoid this, it is necessary to consider the multiplicity of the ratio of the amplitude A to the axial step So.

Simulation of the Processing Process in a Glow Discharge Plasma Generator

A theory has been developed that explains the structure formation in a thin surface layer of a material after low-energy exposure to a glow discharge plasma. This makes it possible to design new methods, technologies and automated devices for the development of an automated technological environment for strengthening various types of tools from various materials. Based on the developed theory, a self-learning system with a developing database was created for monitoring all stages of processing in a glow discharge plasma generator. Any crystal structure can be classified as a complex nonlinear system. When studying the dynamic response of such systems to an external low-energy effect, it was shown that by the time when the nonlinear vibrations stop, the atoms of the crystal lattice are stabilized in new positions. Based on the purpose of the products to be processed in the glow discharge plasma generator, with taking into account their operating conditions, it is possible to increase their production life up to 2 times or more. These technologies should be used at the final stage of the production process because they do not lead to distortion of the shape and size of the working surfaces of products being manufactured. In this case, the residual stresses are redistributed in the surface layer of the material with the formation of an equal structure that improves the running-in conditions of mating parts of devices and mechanisms. For cutting and forming tools, the run-in stage is reduced to the stage of uniform wear.

Scientific and Technical Aspects of Interference Fits Hydropress Assembling Automation Using Mechatronic Press

The study object - technological process of interference fits assembling is identified, the scheme with oil supply from the end face is adopted as the technological scheme. Technological pressing equipment is considered, its applicability for hydropress assembling is evaluated. The main aspects of hydropress joints assembling on a base of mechatronic press are established: increasing of assembling performance, its stability. Mathematical models and an algorithm that regulate the process of liquid friction and formation of an oil layer between the contacting surfaces of joint mating parts are developed. The basic requirements for the regulation channels of control system that ensure the quality of hydropress fits during automated assembling are established.

Conformal Efficiency Factors of Friction Pairs in Construction Machinery

Formulae for the efficiency factor of moving friction pairs of construction equipment are investigated in terms of their mutual adaptation (conformism) during friction and wear. As a basis, the average coefficients of sliding friction and dimensions of the reference line curves, the half-sums of their products of the worn surfaces microrelief for mating parts are taken. Coefficients of sliding friction and dimensions of reference lines were determined from the partial values of microwear and micromaterial of the normalized system of relative reference lines and convergences. Calculated values of conformal efficiency factors were compared with efficiency factors obtained from the tested dependence, as well as from the wedge operator in the dry friction mode. The research was carried out on the example of model hinges of hydraulic excavator attachments.

New approach to elucidating the physical nature of the processes that occur in the friction zone of mates of machine parts

It has been found that during frictional contact in separate local areas of a thin surface layer of parts under significant loads and deformations and high contact temperatures, the material of the tribocontact zone of parts transforms into a special activating unstable state of magma-plasma or triboplasma. General issues in which the nature of the processes of friction and wear of mating parts is clarified are considered at a higher fundamental level with the involvement of nanotribology. A number of processes that accompany interactions of triboconjugations of parts are analyzed: mechanoemission, mechanochemical, gas-discharge, etc., tribochemical reactions, fluxes of high-energy particles: excited molecules, atoms, ions, fast electrons, phonons (sound quanta and quanta of electromagnetic radiation). Regularities of additivity of elastic and magnetic aftereffect in the volumetric parts and surface layers of tribo-interface parts made of ferromagnetic materials and alloys have been revealed. Also, the regularity of the additivity of the diffusion aftereffect in their surface layers has been established. A tribophysical model of self-organization is built on the basis of a carbon-nitrogen cycle of tribochemical reactions that have the content of thermonuclear fusion reactions and which can be considered at the nanoscale. In these reactions, the carbon atom plays the role of a catalyst for the process of fusion of protons with subsequent transformation into a radioactive isotope, which decays into ordinary carbon and helium. It has been established that the mechanism of nuclear fusion reactions in the surface layers of triboconjugation parts is due to the directional movement of dislocations in the crystal structures of materials with the implementation of the proton cycle and the conversion of hydrogen into helium. It has been shown that this makes it possible to change the idea of the mechanocaloric effect, the process of friction and wear, and to substantiate a number of effects and processes from the physical positions of nanotribology. This will allow the creation of competitive tribotechnologies in various industries.

Examination of particulate contamination contents in commercial diesel fuel

The purity of diesel fuel is a crucial issue, in particular in the face of modern injection systems operating under very high pressures with very precisely fitted mating parts. At such pressures and in high temperatures, injectors are particularly exposed to abrasive wear due to the presence of fine, hard abrasive particles in diesel fuel.
 This article presents the results of diesel fuel contamination with abrasive particles in various size ranges (above 1, 2, 3, 4, 6 and 14 µm) determined in accordance with ASTM D7619 and EN 12662. Fuel samples came from leading manufacturers and were collected at filling stations which are the last links of the distribution chain. Furthermore, all diesel fuels were tested for compliance with all the requirements of EN 590.
 Analysing the results obtained, the problem of contamination with abrasive particles was found to be present in Poland. Around 37% of the samples tested did not meet the requirements of the Worldwide Fuel Charter (WWFC) in terms of purity class (ISO code 18/16/13 for particles in the range above 4, 6 and 14 µm according to ISO 4406). Violations of the purity class were found mainly for particles in the range over 4 µm. A very large number of particles from the lowest ranges, which are not included in the Worldwide Fuel Charter (above 1, 2 and 3 µm), were also found, and these may cause damage to fuel injection systems. The number of particles in the range above 1 μm in majority of samples exceeded the class 22, and that of those in the range above 2 and 3 μm was mainly between classes 19 and 21. Moreover, no correlation was found between the results of the particulate matter determination (ASTM D 7619) and the total impurity content (EN 12662).
 Based on the results of the tests carried out, it can be concluded that exceeded number of particles in individual size ranges are not always related to the content of impurities in a form of metallic pulp, impurities from outside the system or the precipitation of enriching additives. Nevertheless, they may be one of the factors contributing to damage to precision fuel injection systems.

Non-abrasive Finishing of Mating Surfaces of Machine Parts Using Mixed Techniques with Electromagnetic Fields Application

In various branches of mechanical engineering, faucets, valves, gate valves and other shut-off devices are manufactured and used. Their main purpose is to regulate the flow rate and direction of flows of liquid and gas media. Features of such products in the aerospace and petrochemical engineering are special strict requirements due to the specificity of their operation. These include, for example, high pressure, resistance to aggressive, fire-and explosive environments, leaks of which are unacceptable according to safety rules and environmental legislation. The design of such products, as a rule, assumes high requirements for accuracy and roughness, especially at the interface of parts, high strength in case of impact pulse effects of the fluids in them. To ensure the above characteristics, finishing abrasive treatment is most commonly used, which can result in the effect of impregnation of the surfaces of products, which will negatively affect the useful life and performance indicators of the mating surfaces. At the same time, it is obvious that mechanical finishing without any use of abrasives is extremely difficult and time-consuming. The authors of the article suggest elimination of the negative effect of impregnation by means of mixed machining techniques with the application of electromagnetic fields. Purpose. The purpose of the work is to develop a technology for non-abrasive finishing of machine parts by developing a model that allows selection or calculation of the production modes of gapless mating parts of locking devices applied in various industries. Methods. The method of the research is the use of the scientific basis of mixed machining techniques, the theory of mass transfer in electrical machining, the fundamental foundations of mechanical engineering technology, modern methods for studying characteristics at the final stages of machining, modern measuring tools, special technological equipment, as well as computer technologies. Results. As a result of the research, new technique and devices were developed. This made it possible to implement a non-abrasive finishing operation of the mating surfaces of parts made of metal materials, the processing of which by mechanical methods is difficult. Conclusion. As a result of the conducted research, it became possible to obtain high-quality high-resource gapless locking products and to reduce labor intensity of the finishing operation up to 5 times and preparation for the production up to 2 times.

WITHDRAWN: Heat transfer analysis for different materials of ball bearing using ANSYS

Abstract ANSYS study is conducted for ball bearing thermal performance such as temperature distribution, total heat flux and directional heat flux for maintain the recrystallization temperature. Because if the temperature continuously increases means it affects the various parameters such as oil viscocity, increases the friction at mating parts and catastrophic machinery failure occurs. In our project we make a design and analysis of the ball bearing with three different materials. Presently the bearing are made by the material of stainless steel, this project we are testing the same load under high chrome and metal matrix materials to determine mkthe thermal performance. If temperature increases means oil viscocity will decreases drastically then the lubrication between the mating parts will become very poor and there is no result in heat reduction. Excess heat could decreases the effectiveness of the lubricating oil and it separate from the thickness. The temperature acting on the inner surface of the bearing is applied and analysis is carried out by using ansys software and determine the total heat flux with directional heat flux.

Effect of the Coatings of Mating Parts on the Strength of Interference Fit Joints

An effective method for increasing the strength of fixation of hard-alloy drill bit roller cutters is developed; it consists in the use of galvanic coatings of mating parts. The strengths of the joints with three types of coatings are experimentally studied. Recommendations are developed for the type and thickness of the coatings of the parts of interference fit joints of hard-alloy bits with the mobile elements of drilling tool.

Algorithm for Accumulating Part Mating Gaps to Evaluate Solid and Fluid Performances

Abstract Part mating gaps need to be effectively adjusted during the assembly of products and greatly affect the working performance. This paper develops an algorithm to calculate the dimensional and aerodynamic indexes affected by part mating gaps. Mating gaps are expressed by displacements of one contact surface, and indexes are evaluated by displacements of key surface, when the surface is ready to compare with the other. A graph that denotes contacts as nodes and related paths through the physical domain as lines is proposed to express assembly sequences and hierarchies. A variable is defined to combine the time set with the displacement set. Boolean algebraic theorems are extended to derive a compact expression for the contact graph that supports the organization of accumulations at different surfaces with propagations through physical domains. Demonstrations of this method using three products exhibit the general applicability, and the application shows that the performance deviations of the centrifugal fan and axial turbine are apparent. In particular, the isentropic efficiency is good with a certain probability, despite turbines having mating gaps. The algorithm benefits both design and assembly: design can be performed through the fluid domain, which is affected by the mating gaps, and when the parts are being adjusted, the selected tolerance limit allows engineers to monitor key surfaces to ensure good aerodynamic performance.

Effect of Aluminium Oxide (Al2O3) Nanoparticles Addition into Lubricating Oil on Tribological Performance

Minimizing friction and wear in between mating parts is the main concern in the field of tribological studies. Lubricants with improved tribological properties are continuously explored for minimizing friction and wear. In the present work, an attempt has been made to evaluate the effect of the addition of aluminium oxide (Al2O3) nanoparticles as lubricant additives on the tribological performance of base lubricant oil (SAE10W40) using four-ball tester. Weight in the percentage of Al2O3 nanoparticles was added in base oil and evaluated the effect of additives on wear preventive characteristic and coefficient of friction of base lubricant oil. Integrated Taguchi-Grey relational approach is implemented to obtain the optimum combination of load and % wt. of Al2O3 nanoparticle addition for improving the tribological performance of base lubricant oil. With a load of 250 N and 0.5 wt% of Al2O3 nanoparticles shows an optimum combination for the improved tribological performance of base oil. The wear scar diameter and coefficient of friction found to be reduced by 20.75 % and 22.67 % respectively with the addition of 0.5 wt% of Al2O3 nanoparticles in base lubricant oil. The lubrication performance seems to be improved because of mending effect and ball bearing effect of Al2O3 nanoparticles forming a self-protective film on the friction surface.

Development of a new method for assembling adjustable cylindrical joints

А new method for assembling cylindrical joints with a horizontal axis of assembly using adhesive compositions with the ability to regulate the relative position of the mating parts was developed. A constructive scheme of the assembly using the developed method is proposed.