Traction Ability Research Articles

GIS-based analysis of relationship between building density and capacity of urban streets

Governments adopted the policy of increasing accumulation in cities in order to maximum use of desired lands of city districts and to prevent from city buildings in the environment created subsequent to the horizontal city developments. One of the basic foundations that must be evaluated while the population accumulation of capability increase, is the traction ability of accountability communication network in both public and private transport system to new travels created by any new user introduction. In this paper, we discussed about the relation between accumulation and traffic capacity of city streets with regard to a case study of Imam Khomeini Street in Tabriz city, Iran. This relation has been modeled with Logistic and AHP models. After investigating the service level of the street for 14 consecutive hours it is evident that the traffic is saturated at the peak hours and based on this study the suggestion for density increase is eliminated. Because the density increase is possible when v/c

Belt drives with increased traction capacity

The design features of belt drive tensioners and belt tensioning methods are studied. A comparative analysis of tensioners showed that special attention should be paid to gears with self-tensioning belts, since neither domestic nor foreign regulatory documents reflect the calculation of such gears. Keywords: belt drive, belt tension method, tensioner, traction ability, slip curve, traction coefficient, transmitted power. n.p.balovnev@mospolytech.ru, yulbrovkina@yandex.ru, alexigorevich@mail.ru

Analysis of the stress affecting the cutting knives locally manufactured in the moldboard plough with the measurement of some of the indicators studied

The study was conducted in a theoretical part, using the finite element method and the main stresses and safety coefficients were adopted on the sliding and disk knives, which are among the auxiliary parts in the work of the moldboard plough. The second part is the field evaluation of performance evaluation of the plough through three factors: cutting knives the sliding knife, the disk knife and without a knife, two levels of moisture content 9.73 % and 16.22 %, and two ploughing depths 15-20 and 25-30 cm. The following indicators were studied: drawbar capacity, fuel consumption, and percentage For slippage, vertical deviation and lateral deviation, the results showed that the subtractive plough without the cutting knife recorded the highest values of the drawbar capacity and vertical deviation, however the plough with sliding knife achieved the lowest values for the indicators which mentioned, the moisture content 16.22% recorded the lowest significant value for each of the drawbar ability and the percentage of slippage and deviation Lateral. Increaseing plough depths achieved the highest value of traction power, fuel consumption, percentage of slippage and lateral deviation, and the overlap between the plough with the sliding cutting knife and the ploughing depth of 15-20 cm achieved the least significant value for the traction ability, and also the overlap for the depth of 15-20 cm with the disk knife plough had the lowest fuel consumption.

Development and Optimization of Traction System for Heavy Engineering Machinery

The traction system of heavy equipment is a key part of the heavy engineering machinery and the traction ability of the heavy engineering machinery have high requirements for the overload capacity, reliability, maintainability, cost, and other aspects of the walking part. With the development of electrohydraulic technology, the traction technology of heavy equipment has also been continuously improved and the driving mode of the traction part has also developed from hydraulic driving to AC variable frequency driving. Engineering machinery is early generally driven by a fuel engine through a transmission shaft, gearbox, drive axle, and wheel reducer to complete the equipment. Heavy truck, bulldozer, tunneling machines, anchor excavators and shuttle trucks are commonly used heavy equipment in mechanized mining and rapid excavation of mines. Their traction performance plays a crucial role in improving the efficiency of working face excavation. This paper introduces the traction system of heavy equipment and compares the hydraulic drive system and electric traction drive system for them. The design scheme of the electric control system and the traction converter system is analyzed and a optimization scheme of the traction converter system is proposed. The optimized frequency converter adopts a modular assembly structure, which is convenient for installation, debugging, and after-sales service. Field application shows that the optimized frequency conversion system improves production efficiency and reduces failure rate.

Engineering Design, Kinematic and Dynamic Analysis of High Lugs Rigid Driving Wheel, a Traction Device for Conventional Agricultural Wheeled Tractors

Traction failure on loose terrain is common in conventional agricultural wheeled tractors due to poor traction ability and lower power transfer efficiency of drive wheels, which leads to excessive energy consumption and soil compaction in agriculture. To overcome the problem, this paper presents a new design of a rigid lugged wheel for use in field tillage operations. This wheel was designed according to field operational requirements and also provided with rubber pads for smooth on-road drives. Kinematic and dynamic analysis of new wheel designs were carried out to study how they move, how they interact with the soil, and how they generate drive force in loose terrain soil. The relationship of wheel lug motion trajectories, displacement, and velocity of the wheel relative to field conditions, different travel reduction rates, and lug penetration/wheel sinkage were analyzed. Wheel-terrain interaction and shear stress-shear displacement relationships when the wheel is driven in soft, deformable terrain were studied using classic soil mechanics principles. It is found that the component of thrust in the direction of driving, i.e., driving force, is ranged between 81.52% and 86.17%, while the vertical component is reported to be less than 30% and further decreases to 9%, which is the compaction avoiding factor. The relationships, thus developed, of wheel parameters, soil stress and thrust characteristics, and wheel drive force were derived and revealed that the traction performance, power transfer efficiency, and trafficability of tractors in loose terrain can be improved by using the newly proposed wheel. A finite element method was used to analyze the designed wheel model for structural stability and optimization. The theoretical analysis results of the new drive wheel are convincing, so further tests and field operation research are recommended for sustainable adoption.

Profiling the cam of the centrifugal screwdown structure of the V-belt variator

We consider the problem of profiling the cam of centrifugal pressure device of the driving pulley of V-belt variator which parameters and, first of all, profile would allow to create the optimal axial forces corresponding to the required mode of the transmission operation. A methodology for determining the required optimum axial forces from the condition to ensure the best traction ability of the belt transmission is given.

A Method for Traction Ability Research of a Rover Wheel on Mixed Planet Terrain with Movable Stones

The mixed terrains of terramechanics research are mainly composed of static stones and loose soil. The movement behavior of stones is often ignored while analyzing the influence of the wheel’s traction performance caused by mixed terrain. When a wheel is in contact with the movable stone and with the loose soil at the same time, the residual soil model, therefore, is proposed to simulate the change of the contact force between the wheel and the remaining loose soil caused by the failure of the loose soil in the area covered by stone. The plastic homogeneous soil mechanics model is proposed based on the soil’s mechanical properties. It is used for simulating the reaction force provided by soil to the moving stones. These mechanical models are compiled into the simulation programs, which are called by Adams to calculate the contact forces and moments of the planetary rover’s wheels in the mixed terrain with the movable stone and loose soil. Carrying out soil bin tests under the same experimental conditions, the comparative analysis of the simulation and experiment for a wheel in contact with 4 types of stones shows that the comparison results are in good agreement, which can verify the effectiveness of the proposed models to an extent.

Asymmetric loading multi-roller planetary traction drive: Modeling and performance analysis

The development of high-speed motors has stimulated the demand for high-speed reducers. Aiming at the lack of high-speed reducer and the NVH problem of high-speed gear transmission, an asymmetric loading multi-roller planetary traction drive (AL-MPTD) scheme is proposed to fill the gap of traction drive with large speed ratio, zero spin and self-adaptively loading. By comprehensively considering the effects of axis tilt, elastic deformation, rough surface contact and elastohydrodynamic lubrication (EHL), this paper establishes a more refined theoretical analysis model and provides the analysis method under the condition of the non-smooth surface and non-ideal contact. This paper also studies the transmission performance of AL-MPTD from the aspects of traction ability, transmission efficiency and so on. The results obtained by theoretical calculations show that AL-MPTD can be considered to achieve zero-spin transmission in the entire operation range. In addition, the loading mechanism achieves a good self-adaptively loading effect, effectively reducing the sliding of the AL-MPTD and improving its efficiency, with the peak of the global sliding coefficient being only 0.402% and the maximum transmission efficiency of 98.5%.

Development of a technique for computer simulation of the stress state of the drive drum shell of a belt conveyor to optimize its design parameters

The paper considers the method of computer simulation of the stress-strain state of the drive drum shell in the NASTRAN integrated environment. Due to the complexity of determining stresses and deformations in the drum sections by the analytical method, it is proposed to solve this important problem using the numerical finite-element method. At the preliminary stage of computer modeling, a mechanical design scheme was developed, including a variable pressure that changes depending on the angle of rotation of the drum, the deterministic relations describing the variable force factors are based on the Euler ratio. It is also proposed to take into account the pressure from the variable friction force, which depends on the changing coefficient of adhesion of the belt to the drum. As a result of the computer calculation, the equivalent Mises stresses of 65 MPa were determined, the safety factor was 4.2 and the components of the tangential stresses were determined using the stress tensor marker, the shear stress reached the level τ=16 MPa for fabric tape and τ=3.14 MPa for rubber tape. According to the results of the calculation, the dependence of the tangential stresses on the angle of rotation of the drum was constructed. A diagram of the change in the component of tangential stresses along the forming shell of the drum was constructed. Analysis of stress-strain state allowed us to determine the factor of safety of the drum shell. Based on the analysis of equivalent stresses, it is proposed to further calculate the durability of the drum using the method of long-term fatigue. The computer calculation of shear stresses in the component allows choosing the rational parameters of the lining, based on such indicators as peel strength and break, as well as determining the angle 61° of the slab lining required to improve the reliability and traction ability of the pipeline

VERTIKAL SHPINDELLI PAXTA TERISH APPARATI TEXNIK SAMARADORLIGINI TA’MINLASH IMKONIYATI

In order for the use of the vertical-spindle cotton picker, created in Uzbekistan, to be economically effective, it is necessary, first of all, to increase its completeness of harvest. This indicator depends on many factors. However, the most important factor is that the spindle friction drive function is inadequate. Friction forces between the friction drive belts and the spindle roller determine its tagging capacity. The magnitude of the friction force depends on the pressure of the belts on the roller, which in turn depends on the tension of the drive belts. The article analyzes how much the tension of the drive belts in economic conditions meets the requirements.Key words:completeness of cotton picking by the apparatus; friction drive; belt tension; traction ability; direction and magnitude of the absolute speed of the spindle tooth; moment of power; variability of the angular speed of the spindle; gripping power of the tooth

Rationale for the thickness of the rubber lining of belt conveyor drums

Abstract. In the paper, the current state of development of transport equipment, namely belt conveyors, is presented. Today, belt conveyors are used in all sectors of the economy and transport thousands of tons of products; their length can reach 15 thousand meters. But along with the widespread use of the belt conveyors there is a problem of their reliability. According to researches, the most valuable and responsible parts such as drum and conveyor belt wear out rapidly and significantly increase the cost of transportation. In this paper, it is stated that the main cause of the drum and belt failure is vibration loads and dirt (transported material, moisture, etc.); besides, with taking into account the trend of increase of the conveyor length, vibration loads also increases, hence, accelerating the drum wear. Therefore, many studies and works of scientists are focused on the problem of interaction between conveyor belt and the drum proposing a lot of solutions on how to increase life of the drum and belt, namely the lining of the drums with high-friction material. And only few of them are devoted to the problem of choosing the optimal thickness of the lining.As the world experience on conveyor construction shows, this problem is quite relevant for conveyor transport and, for a number of reasons, is quite difficult for obtaining an analytical solution. The reason is, first of all, the absence of adequate physical and mathematical models and in a variety of operating factors of different physical nature, especially in zone of the belt contact with the drum when it becomes wet or pieces of transported material occurred in it. It is experimentally established that efficiency of conveyor largely depends on the degree and nature of contamination of the drum because contamination of the inner surface of the belt with particles of transported material (coal, sand, ore, etc.) can lead to a significant reduction in the coefficient of adhesion. When drums with rubber lining are used in the belt conveyors, tractive ability of the belt, as well as forces of friction, is also determined by the rate of deformation of the lining layer. It is experimentally established that value of the coefficient of adhesion is directly proportional to the thickness of the rubber lining and inversely proportional to the hardness of the rubber. The rubber lining of the drum allows to: increase traction of the belt; reduce dynamic forces of the “belt-drive drum” system; reduce vibration stress in parts and assemblies of the conveyor (lining dampens both low-frequency and high-frequency oscillations); reduce belt wear; eliminate or at least significantly reduce the impact of contamination due to special corrugations; reduce a possibility of occurrence of self-oscillating process associated with either high belt speeds (about 20 m/s), or with the phenomenon of its slip: one of the main reasons is contamination in the contact zone. Keywords: belt conveyor, drum, rubber lining, dissipation, dissipation coefficient, physical and mechanical properties, aging, adhesion coefficient.

Influence of breakages of cable groups on strength ofrubber-cable tractive-transporting element

Purpose. Development and justification of a method of analytical determination of a stress-strain state of a flat rubber-cable tractive-transporting element with breakages of continuity of cable groups in different cross-sections. Methodology of research is in development of a mathematical model of interaction of tractive-transporting element parts considering breakages of groups of random cables, construction of analytical solutions for determining dependencies of force distribution between cables and shear stresses in an elastic shell of a tractive-transporting element with random locations of breakages of cable groups in different cross-sections. Findings. A model of a flat rubber-cable tractive-transporting element with random locations of breakages of cable groups in different cross-sections is developed. Expressions that allow determining a stress-strain state of a flat rubber-cable tractive-transporting element of a hoisting and transporting machine with random locations of breakages of cable groups in different cross-sections are obtained analytically in a closed form. Strength conditions are formulated. Scientific novelty is in establishment of dependencies of interaction of disturbance fields of a stress-strain state of a rubber-cable tractive-transporting element with breakages of continuity of random cable groups in different cross-sections. It is established that disturbance fields caused by breakages of adjacent cables overlap when the breakages are located in one cross-section and there are less than three whole cables located between the broken cables. Disturbance fields also overlap when the same cable or the adjacent cable is broken in both cross-sections and the distance between cross-sections of breakage does not exceed the value, which depends on the design of a flat rubber-cable tractive-transporting element and mechanical properties of its components. Practical significance. The obtained algorithms and strength conditions allow determining a stress-strain state and preventing the breakage of the entire flat rubber-cable tractive-transporting element with breakages of cable groups in different cross-sections. These cross-sections can be: cross-section of the edge of a butt joint, where cables have breakages of continuity; cross-section, which includes the edge of an area of partial restoration of a tractive ability of the element, lost due to breakage of a cable; cross-section of cable or cable group breakage during operation. A possibility of establishing a stress-strain state and the strength conditions of a tractive-transporting element under such conditions allows reasonable determination of a possibility of its further operation in a hoisting and transporting machine.

Modeling of mover with anti-skid devices

For a mover equipped with anti-skid devices, the process of slipping is being formed due to the factors of soil compression, shift and cut by tire hooks. With a decrease in the number of removable hooks, the period, when the first hook is disengaged and the second has not yet entered into interaction with the soil, increases. At the moment, traction and hitching properties of the wheel are formed only by tire hooks. During the interaction of the removable hook with the soil, the traction ability of the wheel consists of the shear forces of the soil “bricks” sandwiched between the tire hooks and the soil deformation forces by the removable hooks. With increasing height, length and thickness of the hook, the traction forces of PC and PB increase. However, the hook height parameter, in contrast to the length, is optimized by the diameter of the wheel, the depth of the soil, track and tire deflection. In addition, with an increase in the height of the hook, the resistance to the movement of the wheel increases. The study obtains models of the influence of the hook length lc on the traction and bearing capacity of the hook. With an increase in the slipping process, the ratio of traction forces to implementation increases. Therefore, the functional qualities of anti-skid devices depend not only on the parameters of the hook, but also on the operating modes of the mover. The graphical analysis shows the relationship between the parameters of the removable hook according to the criterion of reliability and performance of the anti-skid system. The influence of the hook parameters on the functional qualities of the removable device, the ability to perform traction propulsion properties is revealed. The paper provides the dependencies for determining the optimal geometric parameters of the removable hook, knowing the dependence of the implementation force on the penetration depth of a unit base area, while taking into account the force on the implementation of the anti-skid device strut.

Chrysotile asbestos ― raw materials of the construction industry from deep quarries

A ladle belt conveyor with increased traction ability is proposed at the request of Kostanay Minerals JSC. A geometric diagram of the conveyor route for cyclic-flow technology with the transportation of rock mass steeply falling conveyors in the contours of the quarry of the first stage of the Dzhetygara chrysotile deposit is given. The calculation of the geometric dimensions of individual sections of the conveyor is performed. The parameters of the transported material, the route and the bucket belt conveyor itself are determined.

Chrysotile Asbestos: Raw Materials for the Construction Industry from Deep Quarries

A bucket belt conveyor with increased traction ability is proposed at the request of Kostanay Minerals JSC. A geometric diagram of the conveyor circuit for the cyclical-flow technology with the transportation of rock mass by steeply inclined conveyors in the contours of the quarry of the first stage of the Dzhetygara chrysotile deposit is given. The calculation of the geometric dimensions of individual sections of the conveyor is performed. The parameters of the transported material, the circuit and the bucket belt conveyor itself have are determined.

Partial restoration of tractive ability of rubber-cable tractive element with damaged cable base

Partial restoration of tractive ability of rubber-cable tractive element with damaged cable base

Influence of variable slip frequency control strategy on tractiv e performance

In order to improve the current situation of poor traction ability of medium-low speed maglev train, a variable slip frequency control (VSFC) strategy is proposed based on the constant slip frequency control (CSFC) of linear induction motor (LIM). The control frequency of the starting stage of the vehicle is selected low on the premise of no obvious influence on the levitation performance. After reaching the maximum power point, the traction of the motor is always the maximum that can be exerted under the corresponding speed. Firstly, the mathematical model of linear induction motor is established, and the analytical expressions of traction and normal force are listed; Then the influence of slip frequency on vehicle tractive performance is analyzed by traction calculation, the VSFC strategy is proposed and its advantages are analyzed. The results show that the VSFC strategy can fully suppress the influence of normal force on levitation stability at low speed, and can give full play to the tractive performance of the motor in the whole process.

Stress-Strain State of a Flat Tractive-Bearing Element of a Lifting and Transporting Machine at Operational Changes of its Parameters

Main indicators of a stress-strain state of a rubber-cable belt, the rubber-cable rope for a random placement pattern and the size of the part with broken cables, including partially removed cables, with cable breakages and their random amount, different conditions of belt interaction in its cross-sections of connection to structural elements of a conveyor and a lifting machine to ensure control of its tractive ability during the life cycle. Performed researches clarify the idea of the interaction mechanism of reinforcing elements in composite materials of layered structure with hard and soft layers. Obtained results can be used for development and justification of a unified technology of creation and engineering support of operation of lifting and transporting machines with flat tractive-bearing elements with increased life-span, level of efficiency and operational safety in systems of extraction, transportation and processing of minerals.

An adaptive sliding mode control to stabilize wheel slip and improve traction performance

Advanced antislip control methods are available these days. However, due to increasing requirements with regard to demand and emerging technologies in the field of railways, further research on antislip control is required. Therefore, in this study, an antislip control algorithm, based on a sliding mode control, is proposed to stabilize the slip and improve the traction ability of a full-scale tram wheel test stand. To verify the validity of the control scheme, a numerical model of a tram wheel test stand has been generated using the MATLAB editor. The Freibauer and Polach contact theory has been employed to determine the coefficient of adhesion and adhesion force. Moreover, the derived algorithm was implemented on a full-scale tram wheel test stand. Experiments were carried out under several wheel–roller surface conditions. The results of the refined numerical model are in good agreement with the experimental data obtained from the tram wheel test stand. For both the experimental tests and the numerical model, the response of the proposed control algorithm is rather satisfactory with regard to the stabilization of the slip and improvement of the traction ability.

Simulation of 8x8 Heavy Duty Truck for Evaluating Effects of Torque Converter Characteristics on Vehicle Performance

This paper investigates the powertrain system of an 8x8 heavy duty vehicle through the integration of two couple of diesel engine with automatic transmission as power sources for evaluating the vehicle performance. The primary goal of this paper is to show the effects of torque converter selection on acceleration performance and fuel consumption of the vehicle. To achieve this goal, powertrain system simulation carried out by using two different torque converter individually according to Heavy Duty Urban Dynamometer Driving Schedule (HD-UDDS) drive cycle. Torque converter alternatives (design 1 and design 2) are chosen considering operational area in moment characteristics of the engine. A mathematical model of powertrain system is implemented based on longitudinal dynamics of vehicle motion in HD-UDDS cycle. Required moments on torque converter during the motion of test cycle are compared for converter alternatives and loading condition of vehicle. Fuel consumption results are also compared by using fuel consumption data and required power in the engine. Results demonstrate that the increase in acceleration performance and traction ability of vehicle can be obtained by selection of torque converter correctly.DOI: http://dx.doi.org/10.5755/j01.mech.24.2.18887