Tractor Chassis Research Articles

Comparative Measurement of Horizontal Penetrometry with a Focus on the Degree of Soil Compaction in Real Work Conditions

Potential soil production is closely related to the physical and mechanical properties. The aim of this paper was to evaluate the effect of different levels of soil compaction created by tractor chassis. The total area of the experimental plot was 13.22 ha. Up until 2019, a conventional tillage system had been used. The measurements were carried out with an innovative measuring device that allows for the continuous measurement of the horizontal penetrometry for comparative measurements while driving, which was designed at the Slovak University of Agriculture in Nitra. The measuring device measured the soil resistance in the tire track (On-track) and out of track (Off-track) as well as in three (50 s) sequences within one tractor pass. Three lines were chosen, where in each a pair of combinations was made. The results were subjected, in addition to graphical evaluation, to single factor ANOVA analysis. When comparing individual passes (PH1 to PH6), the statistical analysis showed that the results of the horizontal resistance measurements proved to be statistically significant (p < 0.05) with respect to the weight, number of passes, and tire underinflation. The highest compaction was caused by the first pass, while the higher weight of the tractor during the next pass had a smaller effect. Underinflating the tires ensured a reduction in compaction. Reducing the tractor tire pressure to 0.15 MPa resulted in a reduction in soil compaction of up to 16%.

ANALYSIS OF DYNAMICS OF VOLUME HYDRAULIC POWER STEERING SELF-PROPELLED TRACTOR CHASSIS

Goal. Analysis of the dynamics of the hydraulic fluid power steering drive of the wheeled tractor self-propelled chassis СШ2540 by simulating the operation of a hydraulic cylinder with a one-sided rod for moving the steering trapezoid when turning the wheels and studying the change in the pressure of the working fluid and the movement of the hydraulic cylinder rod under different load modes. Research methodology. The method of simulation modeling is used, when the variables describing the behavior of the steering hydraulic cylinder are determined by certain load algorithms and operating fluid flows, and are described by differential equations. The differential equations that determine the pressure of the working fluid in the cavities of the hydraulic cylinder and the movement of its rod when the working fluid is fed into the piston or rod cavity are based on the laws of mechanics, the principle of the continuity of the flow of the working fluid and its compressibility. The VisSim package of application programs was used for modeling according to the proposed methodology. The changes of the parameters in the hydraulic cylinder of turning the wheels when they are shifted from the task of the control action in the form of an increase in the external load and the flow of the working fluid in the output channels of the metering pump overcome by the hydraulic cylinder were studied. The influence of the modulus of elasticity of the working fluid, which decreases when it is saturated with undissolved air, was also investigated. The results. When starting the hydraulic steering drive, i.e. when turning the steering wheel from its neutral position, depending on the external load and the intensity of the driver's work at the wheel, oscillatory processes take place in the hydraulic cylinder cavities, which can significantly exceed the working pressure. The results of the research give a reason to conclude that it is necessary to study the nature of the increase in the flow rate and pressure of the working fluid on a full-scale sample of the tractor chassis metering pump, i.e. by replacing the flow rate simulation with its actual value. Setting the loading time and flow rate of the working fluid using the map-VisSim unit is more convenient than setting it with analytical expressions, as it makes it possible to simulate different acceleration rates of the hydraulic cylinder and, if necessary, to control the stationary mode of the steering wheel in the neutral position.

ASSESSMENT OF THE STABILITY OF THE FRONT PIVOT AXLE DURING STEADY-STATE MOTION OF A TRACTOR SELF-PROPELLED CHASSIS

In known scientific and technical literature, insufficient attention is paid to the study of dynamic processes of wheeled vehicles with a steering front axle. The use of front swivel axle on a self-propelled chassis makes it possible to minimize the moment of resistance to turning and reduce the wear of front wheel tires in comparison with rotary guide wheels. This modernization can provide a wider range of attachments for mechanized work equipment. The aim of this work is to increase the stability of the rectilinear steady-state motion of a self-propelled tractor chassis by creating stabilizing moments on the front pivot axle by shifting the axis of rotation of the front axle in the direction of the longitudinal axis of the machine. The stability of the rectilinear steady-state motion of a self-propelled tractor chassis is investigated when creating stabilizing moments on the front steering axle by shifting the vertical axis of rotation of the front axle in the direction of the longitudinal axis of the machine. This scientific article shows that when the steering axle moves, it is possible to reduce the lateral force on the front axle to zero, which makes it possible to reduce the moment of resistance to turning. A straight-line steady-state movement of a tractor is considered, where a violation of the stability of the front steering axle may occur during a short-term impact on an obstacle on the road. In some cases, the angular acceleration and angular velocity of the bridge in the road plane may be the exciting factor. The loading scheme of a front swing bridge under the action of an exciting angular acceleration is determined. The calculation of the effect of the exciting factors on the power steering cylinder is presented. The stabilizing moment that occurs when the axis of the vertical shaft of the front steering axle drive is displaced is determined. The differential equation of the front axle's circular motion was analyzed, which revealed its stability under the action of short-term excitatory forces in the rectilinear steady-state motion of the self-propelled chassis. An estimation of the motion of the front steering axle of a self-propelled chassis is presented, with the determined proportionality coefficients and coefficients of the differential equation, which describes the stable motion of the front steering axle in the steady-state rectilinear motion of the machine under the action of short-term disturbing forces. Keywords: self-propelled chassis, front swivel axle, stability, stabilizing moment, steady-state motion

MATHEMATICAL MODEL OF DIAGNOSTIC BEARING ASSEMBLY OF HUB OF STEERING AXLES OF WHEEL TRACTORS OF DRIVING CLASS 1,4

The machine-tractor fleet of enterprises is an important link in the production of products of various branches of industry in Ukraine. The timely performance of transport, agricultural, road construction and other works, and ultimately the cost of products or services, largely depend on its effective work. Rolling bearings are one of the most common technical devices used in machines. They largely determine the reliability and performance of devices. The resource of the tractor chassis is mainly determined by the resource of the rolling bearings. Defects in the manufacture and operation of bearings affect the vibration signal in different ways and have different diagnostic signs. This makes it possible to identify defects at the stage of their occurrence and predict further development. In this work, the method of vibrational non-destructive testing is considered when diagnosing the bearing assemblies of the hubs of steered axles of wheeled tractors of traction class 1.4. The mathematical model developed by the authors for diagnosing the bearing units of the hubs of steered axles of traction class 1.4 wheeled tractors is aimed at determining the technical condition of the rolling bearings and allows predicting their possible service life. The developed mathematical model allows you to determine the clearances in the bearings, vibration frequencies and the average value of deformation caused by the load on the bearing depending on the frequency of rotation of the separator and the inner ring of the bearing, the initial contact angle of the rollers in the bearing, the radius of the seat of the roller, the inner diameter of the bearing, the radius of curvature of the bearing. An equation was created to determine the unbalance of the hub of the steered axles and the seating clearance of the bearings.

Expanding the technological capabilities of the integral tractor chassis by reversing the transmission

The aim of the work is to find technical solutions that provide a complete reversal of the transmission on the example of an integral tractor, while allowing maximum use of commercially available units or installed as an option for a serial machine. The objects of study are mainly the chassis of a wheeled integral tractor designed for agriculture. The relevance of creating fully reversible transmissions for integral tractors and other agricultural, road-building and transport machines is shown. The variants of installation places for the reverse gear are considered, the features of loading and the principles of designing the reverse gear for specific placement points are analyzed. The most promising options for the case of an integral tractor based on a serially produced chassis were chosen - placement of a controlled power distribution mechanism in the rear axle gear housing or instead of wheel gears. Kinematic schemes and a technique for determining gear ratios and kinematic parameters are proposed. The reverse gear control technologies and the technological base for the design and manufacture of such mechanisms are indicated: when designing an integral tractor in accordance with the principle of maximum unification with a serial chassis, it is advisable to place the reverse gear in the drive axle housing; when developing an original reverse transmission and a new carrier system, the reverse gear should be located in front of the gearbox; in the design of the reverse gear, it is preferable not to use a blocking clutch, replacing it with a planetary gear set and a brake.

PRINCIPLES OF RATIONAL AGGREGATION OF TRACTOR SELF-PROPELLED CHASSIS

The article considers the optimal location of the mounted machine on the frame of the self-propelled chassis for the rational use of traction and coupling properties of the machine-tractor unit. The criteria of their optimal aggregation are determined taking into account the conditions of fulfillment of the corresponding agrotechnical requirements. Recommendations for checking the possibility of aggregating it with a specific attachment are provided. Theoretically and experimentally it is proved that the tractor of classical layout is inferior to self-propelled tractor chassis of similar weight and power in traction, fuel economy, passability, controllability, maneuverability, stability and a number of other parameters and has no possibility of axle suspension. Different layout schemes, redistribution of normal reactions along the axes and the specifics of the force action distinguish the traction dynamics of TSSH from the traction dynamics of the tractor

Dynamic behaviour of a battery pack for agricultural applications

Fight and contrast against climate change and global warming can be considered the most important challenge for the next decades. One of the most involved sectors is the one related to the carriage of passengers and goods, and, recently, also the work vehicles too. The agricultural machines and tractors are no exception to this. Indeed, agricultural industry is the second contributor in terms of pollutant emissions. So, research about agricultural machinery is focusing itself about the development of more sustainable propulsion systems such as hybrid or full-electric solutions. One of the most important components of a hybrid or full electric vehicle is the battery pack. The lack of adequate vibration isolation is the main cause of battery pack failure during operation. In the field of the agricultural vehicles, since the maximum speed is quite low and the weight of the various subsystems are high, combined with heavy working cycles, the dynamic analysis of the battery pack focuses on its low frequency behaviour. In this context, this paper focuses the attention on the dynamic behaviour of a battery pack, thought for a plug-in hybrid electric orchard tractor, through simulations obtained taking advantage of FEM and multibody software. In particular, it will be illustrated the dynamic behaviour of the battery pack while the tractor is moving on a bumpy road and when the tractor chassis is subjected to an impulsive load.

Redesign and weight optimization of chassis and suspension system for a mini tractor

Vibration is an ergonomic challenge for tractor drivers in Zimbabwe. A special mini tractor chassis suspension type for towing was designed, and diagrams of simulations of the chassis and suspension were included in this analysis. A design methodology was used that included tools such as reverse engineering, computer-aided engineering software, and finite element analysis. Finite Element Analysis was used to determine the forces that can be attained by the chassis. Material selection was included, and a selected material simulation was performed, which showed favourable results. The chassis is the major component where the engine, gearbox, and all other controls are mounted. The results presented are the structural characteristics of a modern mini tractor chassis attached to suspension leaf springs. Von Mises using Invertor Computer Aided Design (CAD) software was performed to identify critical regions and obtain design modification.

DESIGN AND LAYOUT OF AN ELECTRIC MOBILE VEHICLE FOR FARMING

Currently, there is an active use of electric transport, including farms, in order to perform technological processes in premises for keeping animals and growing plants. In this regard, there is a need to improve its technical characteristics, increase the traction force, which serves as the most important physical quantity in an electric vehicle. (Research purpose) The research purpose is developing a chassis and main components of the vehicle, choose a traction electric motor of a mobile vehicle with an electric drive. (Materials and methods) An analysis of manual transmission switching in electric vehicles was performed. The article presents the layout of the electric tractor chassis. (Results and discussion) The main components of an electric vehicle (mobile vehicle) are: chassis; traction battery; control charger; electric drive, including multi-speed gearboxes. The use of a gearbox allows you to expand the range of applications of the vehicle. The article presents the type and voltage of the battery to increase the service life of the traction battery. (Conclusions) The chassis and main components of the vehicle were designed. A traction electric motor of a mobile vehicle was chosen. With the use of the proposed complex of the main components of an electric mobile vehicle, it becomes possible to use a manual transmission, which allows increasing the torque. Since the electric motor has a wide range of rotation speed, two mechanical gears (working and transport) are sufficient. A sample of a mobile vehicle was used in the experimental studies.

Increasing the Reliability of the Power unit of the Self-Propelled Tractor Chassis T-16M

Increasing the Reliability of the Power unit of the Self-Propelled Tractor Chassis T-16M

Power Plant for a 0.6­0.8 Class Mobile Vehicle Based on the T­16 Self­Propelled Tractor Chassis

The authors showed the necessity to develop a rear-wheel drive hybrid mobile agricultural vehicle with electric drive and power plant. (Research purpose) To develop and study a new kinematic scheme of a mobile vehicle based on a self-propelled tractor T-16 chassis, which provides increased reliability, comfortable working conditions for the operator, a significant improvement in the environmental situation, and better economic efficiency. (Materials and methods) The authors listed the advantages of the new hybrid vehicle kinematic scheme. They gave the comparative technical characteristics of a diesel engine and an asynchronous electric motor. They developed a new methodology for calculating gas turbine engine technical parameters and described the production process of an electric drive with a capacity of 11 kilowatts to drive the driving wheels. The authors gave a thermal design of the compressor parameters, turbine. They calculated the excess air ratio. According to the parameters obtained, a K27-145 turbocharger was chosen, which simultaneously served as a turbine and a compressor of a gas turbine engine. A kinematic diagram was created with a gas turbine electric generator, storage batteries, an asynchronous frequency-controlled motor and a mechanical gearbox. (Results and discussion) The authors proposed to use a mobile vehicle as a mobile power plant: an output socket with a voltage of 220-230 volts operated from an inverter connected to batteries; the second socket – with a three-phase voltage of 400 volts – from the generator of the power gas turbine plant. (Conclusions) It was proved that the proposed hybrid mobile vehicle design on a battery and a gas turbine was capable of operating throughout the entire working day, and to provide 16 horsepower of a diesel engine, it was enough to install an asynchronous electric motor with a capacity of 7.5 kilowatts. The authors calculated the compressor performance of the gas turbine engine, which was 0.178 kilograms per second. The geometric parameters of the combustion chamber and the technical characteristics of the turbocharger were determined.

Power distribution mechanism for the transmission of forest tracked and wheeled vehicles

The article schematically considers a proposal for development and application of a controlled power distribution mechanism for machines involved in timber industry and agriculture. Use of the mechanism will increase energy efficiency of skidder and forwarder on tractor chassis, improve steering quality of tracked vehicles and improve controllability of wheeled vehicles. For articulated vehicles, use of a controlled power distribution mechanism is expected to reduce stresses on swing mechanism. The article presents analysis results of literary sources on problem of using controlled power distribution mechanisms in transmissions of tracked and wheeled vehicles. Advantages of using such mechanisms in transmissions of tractors and forest vehicles on their chassis are shown. References are given to publications containing descriptions of mechanisms that are similar in characteristics to the developed one and known methods for determining main parameters of power distribution mechanisms, approaches to kinematic, force analysis and energy balance construction of such mechanisms. Kinematic diagram of a new controlled mechanism of power distribution is considered, main parameters, control technologies, and areas of its application are determined. Links between the project and currently developed capabilities of Russian production are outlined. Development prospects of technology for controlling distribution of power in transmissions of tracked and wheeled vehicles in the field of transport engineering are indicated. A reference is given to the research complex created and used at the Peter the Great St. Petersburg Polytechnic University, as allowing to conduct comprehensive tests of experimental models of transmissions of transport and traction vehicles.

Development of an unmanned tractor chassis for precision farming

The development of the chassis of an unmanned tractor for a local complex of precision fanning is considered. The design is based on the kinematic scheme of the shaft gearbox, which implements a large number of modes and the principle of two-line transmission. A feature of this scheme is the presence of parallel load shafts. Keywords: wheeled tractor, autonomous control, two-line transmission, slipping, disc friction clutch. sergey_voi@mail.ru

Optimization of mini plantation tractor chassis by using multi-objective response surface methods

To meet the requirement of the oil palm plantation industry, mini plantation tractor chassis is developed with increasing of transport capacity from 500 kg to 750 kg. The design goals of optimum design are safe, transport efficiency and lightweight chassis weight. The aim of this study is to determine the effect and optimum conditions of design parameters in the form of profile width, profile height, and profile thickness of mini plantation tractor chassis. The parameter design is set by 3 levels. Chassis modeling is done by using Finite Element Analysis software with 3-dimensional model. The deformation and stress behavior are observed on the chassis due to vertical bending and the torsional loading model. Multi-Objective Response Surface Methodology was applied to obtain the optimum design parameter conditions on the results of stress and deformation observation on the chassis. Based on the RSM optimization results, three optimum chassis design candidates were produced. In the vertical bending loading model, it is found that the profile width has the greatest influence to stress reduction contribution, and the profile height has the greatest influence to deformation reduction contribution. In the torsional loading model, the profile height has the greatest influence to stress reduction contribution, and the profile thickness has the greatest influence to deformation reduction contribution. The optimum design based on consideration in both loading models is profile thickness = 5.5 mm, profile height = 100 mm, and profile width = 55 mm.

Soil pressure and pulling behavior of standard and halftrack tractor chassis concepts

The investigation deals with the specific behavior of tire and new half-track based tractor chassis concepts under pull-condition, where horizontal and vertical forces occur between tractor and implement. These forces lead to a change of the front- and rearaxle loads, compared to non-pull condition. The pulling forces lead to a pitch effects of the tractor and can also result in a pitch effect of the track system, depending on the design of the track system. This effect can lead to an uneven contact pressure in the belt-soil contact. To evaluate the pitch effect and the risk of soil compaction, measurements of the ground pressure with “Bolling Sensors” have been carried out to indicate the effect of the pulling forces to the tractor chassis and the soil pressure. The investigation of the ground pressures have been done in a comparison of a standard tractor Axion 960, two half-track tractors Axion 960 TerraTrac and CASE-IH Magnum 380 Rowtrac under pulling conditions with specific ballasting configurations. The investigation of the pulling behavior of the tractors have been executed as a compari-son of two Axion 960 tractors, one in standard tire version and the other as half-track ver-sion. Both tractors have the same configuration of engine-power and transmission config-uration with CVT transmission. The results are, that the CLAAS Terratrac track system features a significant reduced soil pressure in no-pull and also in pull-condition in comparison to standard tires. Also in com-parison to a triangle track system with positive drive principle the soil pressure of the CLAAS Terratrac system with the suspension is much lower. The comparison of pulling performance shows an improved pulling potential at speeds < 10kph of the Terratrac sys-tem. At higher speeds, the tire-soil contact is not the limiting factor and so wheeled and track-typed tractor show a similar pulling performance.

Tractors Hydraulics System Stress Testing Design and Experiment

This paper aims to research and analysis the tractor hydraulic suspension system stress. The hydraulics system was hooked on the latest developed hillside tractor chassis, this experiment used load test method and portable hydraulic testing instrument to test the cylinder movement process and force process. It can be concluded from the drawn curve that when the system loads 2940 Newton, the maximum working pressure is 4.4Mpa. When the system loaded 3920 Newton, the maximum load is 4.8Mpa. The pressure difference between the left and right levers is 2Mpa. The conclusion can provide data validation for the simulation analysis of tractor suspension system as well as an effective reference for the design scheme of tractor suspension system.

An automatic procedure based on virtual ergonomic analysis to promote human-centric manufacturing

Today manufacturing enterprises aim not only to deliver high-value, cost-effectively products in a sustainable way, but also to consider the quality of the working environments. The analysis of human factors, which strongly affect time and quality of manufacturing processes, are crucial for satisfying people involved in the manufacturing process and making them safe, preventing diseases, errors and excessive workload. The paper presents a structured procedure to automatically extract data from virtual analysis made by digital manufacturing tools and measure a set of indicators to validly assess manufacturing ergonomics. The research considers the state of the art in manufacturing ergonomics and defines a set of indicators suitable for manufacturing manual operations, focusing on assembly tasks. Furthermore, it defines a methodology to automatically extract data valorising the selected indicators and an application, based on Visual Basic, to generate the specific task list and related assessment. The result is a rapid and objective assessment, independent from the experience of the user, which can be executed during process design. The procedure has been applied to an industrial case study, where the manual assembly of cabin supports on the tractor chassis has been analysed in order to correct the most uncomfortable steps and obtain a more ergonomic process. A decrease of the EAWS score, calculated with the proposed method, allowed to validate the proposed solution, suggesting a redesign of the assembly cycle to improve the working conditions. Such a procedure anticipates the analysis of the workers’ wellbeing during the design stage to support the definition of human-centric manufacturing processes, simplifying and accelerating the assessment activities.

Application of water borne paint on the tractor chassis

This paper introduces the test and application of cleaner water borne paint coating mode on great wheel tractor chassis.

Automation Highlights from the Literature

Automation Highlights from the Literature

Comparison between different protective devices for agricultural wheeled narrow track tractors and a risk index in orchard work

Since occupational accidents often occur in farm tractor drivers, it is extremely important to focus the attention on specific devices in order to avoid risks from tractor overturning. This phenomenon is actually considered as the leading cause of deaths or injuries related to agricultural work. The system adopted to reduce the above-mentioned risk consists of passive protection devices aimed at preventing the hazardous event which may affect workers’ health. More precisely, the tractor chassis (i.e. ROPS) and the proper seat belt define a “safety volume” around the worker. The aim of the present research is to carry out tests on narrow-track wheeled tractors with fixed roll over protective structures in those areas – such as hazel and olive groves and vineyards - where problems related to under–tree activities occur. This is to implement planting layout and/or cultivation techniques which can be considered suitable for tractors with roll over protective structures. According to that, their project parameters – i.e. safety volume, seat position and typology, test methods - can be successfully modified and improved. The results show that nowadays only a few agricultural vehicles are provided with specific fixed devices able to work under tree without damaging orchards.