Transport Machines Research Articles

The Definition of the Parameters of Innovative Transport and Technological Equipment for the In-Road Pavement Recycling, Using the Method of The Analysis of Fourth Coordinate of The Process

The features of the workflow of innovative transport and technological machines with non-waste technology, multi-purpose machines, recyclers and others similar are described in the article. The calculation methodology for determining the optimal parameters of machines and modes of operation, based on method of the analysis of fourth coordinate (duration) of the operating cycle, is presented. Dependences for determination of the power drive units of recycler are given. The procedure allows optimizing the parameters of the individual equipment units and of the entire recycler machine is described.

ПРИМЕНЕНИЕ АМОРТИЗАТОРОВ АВТОМОБИЛЬНОГО ТИПА ДЛЯ ДЕМПФИРОВАНИЯ РЕЗОНАНСНЫХ КОЛЕБАНИЙ В ТЕХНОЛОГИЧЕСКИХ МАШИНАХ

Introduction: Many vibration transport and technological machines (VTTM) such as conveyors, screens, crushers, etc. operate in a high-frequency mode, or above resonance. Resonance occurs during machine start and slowdown, resulting in sharply rising values of the amplitude and velocity of oscillations. Resonance affects VTTMs adversely due to increased dynamic loads reducing machinery operating life and reliability and causing the noise. Purpose of the study: We aim to provide a theoretical substantiation for the possibility to apply automotive shock absorbers to VTTM oscillatory process control and develop an example of practical implementation for such a device. Methods: The method of controlling oscillatory processes in VTTMs lies in the use of dual-mode shock absorbers. In the operating mode, shock absorbers offer minimum resistance to motion. In the resonance mode, resistance increases, therefore, the amplitude decreases to a predetermined value. Results: We simulate the VTTM oscillatory process in order to determine the characteristics of a damping device, which ensures the suppression of resonant oscillations but does not affect the vibration operating process. We propose a new technical device implementing the required oscillation characteristics. The device is made in the form of a hydro-pneumatic shock absorber, similar to automotive shock absorbers in terms of design. Such a design makes it possible to offer slight damping of the machine’s useful (operating) vibration, but, at the same time, damping increases significantly in the case of resonant amplitudes. The originality of our study lies in the development of a new type of hydraulic shock absorber, for which a utility model patent has been obtained. The scientific novelty of the study is in the mathematical description of oscillation damping with the new shock absorber, in the development of software for oscillatory process analysis according to the developed mathematical model, and in the results of computer simulation for shock absorber operation.

Mathematical model of the cabin suspension system for grain and forage harvesters taking into account the dynamic properties of the supporting system

The paper is devoted to the study of the vibrational state of the operator's workplace of a transport-technological machine with a supporting system that undergoes torsional and bending elastic deformations during operation. Based on the previously carried experimental studies, the relevance of the work was substantiated and the goal was set to develop a computational model of spatial vibrations of the cabin on a non-existent system in the form of elastic cantilever beams. An original mathematical model of cabin vibrations on an elastic foundation is presented. It takes into account the nonlinear elastic and dissipative properties of the supporting system structure. A variant of the implementation of the developed mathematical model using the example of the mathematical modeling environment Mathcad is proposed. As an example of calculating the dynamic properties of a bearing system, a case of using the MSC Adams software package with an integrated finite element calculation module Flex is shown. It is presented that taking into account the dynamic properties of the carrier system in the model makes it possible to calculate the vibration load of the cabin with high accuracy and reproduce the resonance phenomena caused by the natural modes of vibration of the carrier system and disturbances from technological sources. The results of the verification of the computational model based on the analysis of the convergence of the values of the full corrected vibration acceleration in the center of mass of the grain harvester cabin, as well as the vibration spectra in linear directions obtained by experimental and computational methods, are presented. Directions for the development of measures and technical solutions for improving the vibration load of operators of transport and technological machines who have active sources of power disturbances on board, as well as a supporting system that experiences elastic deformations during operation are proposed.

Increasing the life of plunger and barrel assembly of high pressure fuel pumps

In order to identify the regularities of further increasing the efficiency of transport and technological machines, it is of interest to consider the issues of determining the impact of their design and technological parameters on the quality of running-in and the operability of fuel pumps. The article analyzes the influence of the initial operating modes and the lubricating medium on the quality of running-in and subsequent performance of high-pressure fuel pumps. On the basis of theoretical studies, equations were obtained to determine the unbalanced radial force acting on the plunger and fuel leaks in the plunger pair. These expressions make it possible to establish the dependence of the specific pressure in the plunger and barrel assembly both on the design and technological parameters of the pump.

Прогнозування і управління надійністю в умовах застосування запобіжних пристроїв з детермінованим навантаженням спрацьовування

Reliability prediction of machinery parts being designed is primarily aimed at avoiding mechanical failures in service, caused by the influence of force mechanical interaction of parts among themselves and with the environment. Special attention should be given to sudden mechanical failures due to the fact that their development, unlike gradual failures, as a rule, does not lend itself to individual diagnosis and prevention. In addition, as practice shows, sudden failures can often occur in the initial operation period of the equipment, which adversely affects its competitiveness when it is introduced to the market. Most transport, agricultural, road-building and other mobile machines has operating conditions, use modes, and, therefore, modes of mechanical loads of elements with a wide range of variation. Most time, a machine normally operates under normal (nominal) load conditions, whereby long-term performance and durability should be provided. However, in some relatively rare cases, some parts of machines experience short-term and repeatedly repeated effects of extreme loads close to breaking or inelastic material deforming material details. The book is devoted to a brief review of the fundamentals of one of the many directions of science of reliability - predicting risks of sudden mechanical failures and associated reliability indicators. The safety factor is a generalized parameter which in many respects determines the future material consumption and the cost price of the designed product. Therefore, dependencies linking the safety factors of the machine parts with the predicted reliability indexes allows, at the design stage, to choose a rational and economically feasible option to ensure a sufficient level of reliability. The same concerns justification for tusing safety devices that provide mechanical reliability. Therefore, the use of a set of methods for forecasting and managing reliability stated in the book should improve the efficiency of work related to the design of engineering products. The above reliability models of elements and systems protected from repeated impact of overloads by means of a safeguard with a nearly constant actuation load can serve as a theoretical basis when being designed and during modernization of machinery elements to manage reliability rationally.

Theoretical study of throttle valve system operation in the hydropneumatic shock absorber of the transport and technological machinery undercarriage

In the Arctic zones, there are almost no asphalt roads, which is why in winter people have to move along roads with deep snow, and in summer — through wetlands and boggy mud of the thawing tundra. To transport passengers and goods in such conditions, special machinery with increased cross-country ability is required. When a transport and technological machine (TTM) moves along a road with a variable profile, its suspension executes oscillations, which are damped by shock absorbers. They ensure movement smoothness and stability of contact patches, which is achieved by providing the shock absorbers with the required hydraulic characteristic. Therefore, it is reasonable to equip the TTM suspension with shock absorbers with a controlled throttle valve system in order to adjust damping characteristics depending on external factors. In this paper, we describe a new design of the throttle valve system used in the hydropneumatic shock absorber and analyze its operation.

Synthesis of a system of inertial dynamic stabilization with control according to a set of parameters measured on board a self-propelled vehicle

The work is devoted to the development of the direction of inertial dynamic damping and stabilization of self-propelled transport and technological machines with a mounted working body. The necessity and possibility of improving the previously developed control equations for the stabilization system has been substantiated. The description of the approach for the synthesis of the control system is given and the application of integral criteria for the formation of requirements for the transient processes of the control system is substantiated. A model of optimal control is proposed, for providing the information field of which a set of parameters measured on board the self-propelled vehicle is determined. The algorithm of the control system is adaptive, automatically reconfiguring the gain in the system depending on the change in its inertial parameters. On the example of the kinematic diagram of the drive by the mobility of the adapter of a modern forage harvester, a design diagram is presented for recalculating the values of the required stabilizing moments into the force developed by a hydraulic cylinder or other executive drive. The requirements for the information field of the stabilization system are given in the form of a set of measured parameters, the range of their measurements, the locations of the sensors and the permissible measurement errors. A set of criteria for the effectiveness and efficiency of the stabilization system is proposed. On the basis of numerical experiments, the values of the tuning coefficients of the stabilization system were selected and the transient processes of changes in the angles of the longitudinal inclination and the longitudinal angular velocity of the body were constructed under a single shock loading of the machine. It is shown that the proposed approach provides asymptotic stability of the considered oscillatory system. In order to assess the performance on the basis of simulation modeling, oscillograms of changes in the angles of rotation of the adapter and the forces on the rod of the hydraulic cylinder when the combine moves with the stabilization system turned on on a dirt road and asphalt concrete at different speeds are constructed. The evaluation of the development efficiency is given. The conditions for the modernization of the existing generation of combines for their equipping with the proposed stabilization system are formulated. Conclusions are formulated and directions for further research are determined.

АНАЛИЗ МЕТОДИК РАСЧЕТА ЗУБЧАТЫХ ЦИЛИНДРИЧЕСКИХ ПЕРЕДАЧ НА ГЛУБИННУЮ КОНТАКТНУЮ ПРОЧНОСТЬ

Spur gear is an integral part of transport and technological machines structure. To increase the load ability of the spur gear, chemical heat treatment of the working cogs surfaces is used. Spur gear with chemical heat treatment must be checked for deep contact strength. The article analyzes various methods (according to GOST 21354-87, methods using the generalized criterion of the limit state for structurally inhomogeneous material by Lebedev-Pisarenko, methods from the handbook describing reducers of power machines etc.) for calculating spur and helical gearing for deep contact strength. The author presents all necessary formulas and graphs for the implementation of each methods, and compares the calculations results of these methods with the results of experimental studies of cemented cylindrical rollers for deep contact destruction.

Development of Construction and Repair Materials Used in Transport and Technological Machines Operating in the Arctic

Increasing the pace of development of the Arctic zone, among other tasks, requires the attraction of significant production resources to improve the transport network, in particular, road construction equipment and technological equipment. Extreme climatic conditions, including low air temperatures and strong winds, are features of the Arctic zone. In this regard, there is a need to form a methodological basis for the development of construction and repair materials for use in the Arctic. To solve this problem, based on the results of mechanical tests at temperatures of +20°C, -30°C and -50°C, the possibility of using carbon fiber plastics with various types of hybrid matrices for the manufacture of mechanical engineering products operating in extreme conditions of the Arctic and the creation of reinforcing linings during their repair. The indicators of manufacturability during repairs under the conditions of constant exposure to negative temperatures using polymeric materials are considered.

Directions for the development of transport machines for open-pit mining

The paper is devoted to the identification (in the form of an intermediate obtained result) of the main trends in the development of transport machines, their systematization, taking into account the current state of art, identification and assessment of the most significant trends in view of innovative prospects. The discussed technical solutions contribute to a significant modernization of transport systems of mining enterprises.

The micro contact model of friction materials in friction hoisting-and-transport cars at different temperatures

In the paper there is proposed computer model of the contact of friction materials in the brake devices of building road machines and lifting transport machines at different temperatures. The contact surface is modeled by a microrelief composed of a set of elements in the form of rods. As a result of modelling, there are such contact characteristics as rapprochement, distribution of contact pressure, real contact area and the gap between the surfaces. The obtained dependencies are compered with the finite element method. Keywords computer model of contact at diggerent temperatures, temperature influence, contact of friction material, actual contact area, contact pressure distribution

Modeling of supply processes for perishable foodstuffs

Contemporary experience has proved the necessity of ensuring unity in the transport and logistics systems of food supplies. This is particularly relevant for perishable goods, the acceleration of delivery dates directly impacts their safety and quality. The article considers the problem of creating an effective transport process for perishable food supply chains. The analysis of influencing the efficiency of perishable food supply chains and the main principles and approaches to improve the transport support of perishable food products have been substantiated. The constructed theoretical model of a technological transportation system for perishable food goods considers compatibility (adaptability) of transport machines with agricultural machinery; technological parameters of technical systems; adaptability of technical systems to environmental conditions and technological properties of perishable food cargoes; transport and technological cycles parameters.

Possibilities for Energy Saving Predictions in Elevators

Abstract Today, with the longing for smart and sustainable transportation, the elevator industry has undergone major metamorphism in the field of control algorithm, electric drive, and the motor. Amongst these, regenerative drive (RD) plays a pivotal role in making elevator technology more energy efficient. Rather than wasting the recovery energy from the machine as heat, RD recovers it as green energy. Conventional direct current (DC) motors ruled the elevator industry for many years and were adopted as standard type of elevator motors. But with the advancement in electric drive technology, alternating current (AC) motors, especially induction motors, flourished in the later part. Recently with the introduction of Permanent Magnet Synchronous Motors (PMSM) technology, the elevator revolution began in terms of power quality, ride quality, and green energy. Likewise, contrasted with different types of vertical transportation machines, PMSMs have better powerful execution, compact size, and higher system-level efficiency. Recently, with the rapid improvement in intensity hardware, utilization of rare earth magnetic materials, and indubitably advanced research, PMSM has rapidly changed systems globally. PMSM is a multivariable, nonlinear, and high-coupling framework. The torque and stator current present a unique capacity connection. Attractive fields can be decoupled to gain decent power outcomes. With the presentation of regenerative PMSM, electrical drives coupled to system integrated frameworks for recovery energy has enhanced savings in power consumptions.

Ensuring the Stability of Agricultural Transport and Technological Machines Equipped with Ultra-Low Pressure Tires during Braking

Introduction. Improving the efficiency of agricultural operations and off-road logistics require new highly efficient non-road machinery with low pressure on road surface. The versatility of the use of this machinery imposes additional requirements on its design, including those related to road traffic safety on public roads. Changes in brake design are required to ensure safe braking performance when larger diameter wheels are used for the reason that to produce standard braking force according to the technical regulations for the safety of wheeled vehicles, requires more braking torque when using larger diameter wheels. Materials and Methods. The article proposes a model for calculating the braking parameters of transport and technological agricultural machines equipped with ultra-low pressure wheels. The model differs from those used earlier in that its output parameter is not the braking efficiency, but the time difference between the front and rear axle locks. Results. Fulfilling the condition of the front axle advance locking ensures the stability of the tractor motion during emergency braking that has a positive effect on road traffic safety. The results of the study suggest that to ensure the safe motion of the machines equipped with ultra-low pressure tires on public roads, it is necessary that the ratio of the distance from the center of mass to the front axle is at least not less than the distance from the center of mass to the road surface. Discussion and Conclusion. The proposed mathematical model has shown its adequacy. The obtained mathematical dependencies allow us to justify different technical solutions for ensuring safe road movement of transport and technological agricultural machines equipped with ultra-low pressure tires. Thus, the maximum permissible height of the center of mass can be assumed to be equal to 90% of the distance from the location of the center of mass of an agricultural transport and technological machine to its front (controlled) axis.

A hybrid reliability-centered maintenance approach for mining transportation machines: a real case in Esfahan

PurposeThe purpose of this study is to propose a hybrid reliability-centered maintenance (RCM) approach for mining transportation machines of a limestone complex, a real case in Esfahan, Iran.Design/methodology/approachCriteria for selecting critical machines were collected within literature and selected by decision-makers (DCs), and critical machines have been identified using the preference ranking organization method for enrichment of evaluations (PROMETHEE). Also, multi-criteria decision-making (MCDM) methods were used in addition to failure mode, effects and criticality analysis (FMECA) for selecting and prioritizing high-risk failures as well as optimizing the RCM performance. More specifically, the criteria of severity, detectability and frequency of occurrence were selected for risk assessment based on the previous studies, and were weighted using the analytic hierarchy process (AHP) method. Also, the technique for order of preference by similarity to ideal solution (TOPSIS) has been applied to prioritize failures' risk. Finally, the critical failures were inserted in the RCM decision-making worksheet and the required actions were determined for them.FindingsAccording to the obtained values from PROMEHTEE method, the machine with code 739-7 was selected as the first priority and the most critical equipment. Further, based on results of TOPSIS method, the failure mode of “Lubrication hole clogging in crankpin bearing due poor quality oil,” “Deformation of main bearing due to overwork” and “The piston ring hotness due to unusual increase in the temperature of cylinder” have the highest risks among failure modes, respectively.Originality/valueRCM has been deployed in various studies. However, in the current study, a hybrid MCDM-FMECA has been proposed to cope with high-risk failures. Besides, transportation machineries are one of the most critical equipment in the mining industry. Due to noticeable costs of this equipment, effective and continuous usage of this fleet requires the implementation of proper maintenance strategy. To the best of our knowledge, there is no research which has used RCM for transportation systems in the mining sector, and therefore, the innovation of this research is employment of the proposed hybrid approach for transportation machineries in the mining industry.

ANALYSIS OF UNIVERSAL CHARACTERISTICS OF HYDRAULIC FLUID POWER TRANSMISSIONS OPERATING IN A COMPOSITION OF HYDRAULIC-MECHANICAL TRANSMISSIONS FOR DIFFERENT WORKING VOLUMES OF HYDRAULIC MACHINES OF AXIAL PISTON TYPE

When victorious in the day-to-day infrequent hydraulic fluid power mechanical transmissions (HVMT), the hydraulic fluid power transmissions (HVT)), which are supported by the implementation of all the demands of the daily transport diesel engine, are absolutely necessary in a wide range of for the analysis of the flow of pressure in the HVMT, coefficient of efficiency, thermal images in the motor-transmission drive, traction and propulsive characteristics of the transport machine. More informational and effective when analyzing the universal characteristics of the HVT, which should be entered before the HVMT warehouse. The statute is assigned to the scientific enrichment of the need for a recurrent procedure in the case of the value of the working parameters of the HVT, the automated inducement of the universal characteristics of the hydraulic volume transmissions, the adjustment of the characteristics for the different working types of the central storage of the hydraulic drives.

Increasing the efficiency of agricultural transport and technological machines in the operation

Production of commercial agricultural products is impossible without transport and technological machines and their technical-readiness, through repair and maintenance. The relevance of this direction is due to the agricultural producers’ lack of necessary material and technical base, required production structures, taking into account multistructurality, and various forms of ownership. The use of transport and technological complexes and maintenance tool for their setting and adjustment allows to reduce labor costs and improve the quality of mechanized works. With the increase of commercial agricultural production technical capacity, some issues have emerged: increasing the costs of machines, increasing expenses of production per unit, and also the complicated operation system of mechanisms. As a result, the indicators of their use are not improved. Reformation of management methodsin agriculture is aimed to solve the issues of technical and economicprovision of agricultural products producers with the necessary technical resources. To solve this problem, differential standards of resource requirements should become essential, taking into account the production volume. It is necessary to increase the technical-readiness of transport and technological machines and thus the cost-effectiveness of their use.

MATHEMATICAL MODEL AND AREA OF EXISTENCE OF THE FAMILY CRANKS AND MOBILE MECHANISMS WITH THE MAXIMUM TRANSMISSION ANGLE

The article examines crank-rocker mechanisms. Such mechanisms are used in transport and technological machines. The article is devoted to the search for a new family of crank-rocker mechanisms. A mathematical model of a new family of crank-rocker mechanisms is obtained. In this family, the maximum transmission angle reaches 90 when the crank angle is 75. Thus, the new family of crank-rocker mechanisms differs from the known families by the position of the mechanism in which the maximum of the transmission angle function takes place. It is shown that, with a certain ratio of link lengths, the new family corresponds to the known families KKM-5 and KKM-7. The area of existence of a new family of crank-rocker mechanisms is established. This area is bounded by the arc of the circle of the unit radius and the curve. The mentioned curve is based on a joint solution of a mathematical model of a new family of mechanisms and the famous Kolchin straight line. The dependence for the minimum transmission angle is obtained. A formula for determining the angle of the rocker arm span is proposed. A graphical interpretation of the mentioned dependencies and formulas is constructed. The scope of existence of a new family of crank-rocker mechanisms and graphical interpretations are used in determining the geometric parameters of mechanisms. These mechanisms are part of a new family of mechanisms.

Estimation of the losses coefficient of the vibrational energy of the woodworking technological system

Domestic machine tool equipment is not worse than foreign analogues in terms of product processing accuracy, productivity and reliability. However, almost all machines (including woodworking ones) create sound pressure levels at the operator’s workplaces that significantly exceed the maximum permissible values. Compliance of vibroacoustic characteristics of technological equipment with sanitary standards is not only one of the most important ergonomic criteria, but also largely determines the competitiveness of domestic equipment. The article developed methods of acoustic calculation of metal-cutting equipment, which take into account the coefficient of losses of the vibrational energy of the source, which is a frequency-dependent parameter. Experimental results and regression relationships were obtained for steel plates of various thicknesses, rolled products of multiple configurations, for transport machines and for glazing elements. For woodworking equipment, this data is obtained only for multilayer materials. For various types of wood, at present, such studies have not been carried out, which in fact determines the relevance of the materials in this article.

Electrohydraulic technology for processing triplex glass in the recycling of transport and technological machines

Transport and technological machines are one of the most popular types of equipment used for the development of modern civilization. Unfortunately, their production involves high costs of material, raw materials and energy resources, and their use has a significant negative impact on the environment. The article considers some factors of such an environmentally harmful impact, in particular, related to the process of recycling machines. The importance of solving the problem of resource saving due to the secondary use of structural materials is noted. The current state of technological support for the process of processing triplex automotive glass is analyzed, the disadvantages of existing technologies are noted, and a technology based on the application of electrohydraulic effect is proposed for use. The results of laboratory experimental studies of the effectiveness of this technology in the recycling of automotive triplex glass are presented. The conclusion is made on the feasibility of applying the technology on an industrial scale.