Dependencies of the lead of front driving wheels on different tire deformations for a MFWD tractor

Tractors are the main machines in agricultural production processes. Agricultural tractors commonly employ a four-wheel drive transmission. To reach maximum efficiency in production works, tractors are loaded by as high thrust as possible. The consequence of it, quite often, is that the slippage of driving wheels grows to the limit that is not allowed. To reduce the slippage, various ways are pointed out in terramechanics. One way is to increase the tractor’s weight by adding ballast. The other way is to increase the contact area between tires and the supporting surface. The slippage can be also reduced with traction control and other relevant systems. These methods, which help to reduce slippage, also affect tire deformation. When proportion of tires deformation is not the same as proportion of their sizes, the consequence is change of the lead of front wheels. In this paper analysis is presented, how the lead of front wheels affects the work of MFWD tractor in different conditions. Test results are presented for a MFWD tractor, how the lead of front wheels varies depending on deformation ratios between front and rear tires. For a MFWD tractor, values of deformation ratio between front and rear tires were determined, which ensured effective and which produced unreasonable values of lead of front wheels. First published online: 17 Jul 201

Influence of Air Intake Parameters on Diesel Engine Performance

Šiuo metu vis gausėjantis transporto priemonių skaičius ir didėjantys išmetamų teršalų kiekiai atmosferoje, skatina vyriausybes griežtinti reikalavimus VDV deginių emisijai. Vieni iš kenksmingiausių elementų deginiuose yra azoto oksidai NOX, kurie sąveikaudami atmosferoje sudaro rūgštinius junginius. Vandens dalyvavimas degimo procese taip pat mažina šių teršalų koncentraciją deginiuose. VDV maitinant vandens ir degalų emulsijomis gaunama mažesnė NOX koncentraciją deginiuose, bet tai neigiamai veikia visą variklio maitinimo sistemą. Šiame tiriamajame darbe nagrinėjamas vandens poveikis dyzelinio VDV deginių emisijai. Siekiant išvengti galimo neigiamo poveikio variklio maitinimo sistemai bei dėl paprastesnio dozavimo, vanduo įvedamas į variklio įsiurbimo traktą garų pavidalu. Tyrimai atlikti varikliui dirbant be vandens garų bei įvedant vandens garus į variklio įsiurbimo traktą trimis skirtingomis koncentracijomis. Tyrimais nustatyta 12 % didesnės lyginamosios efektyviosios degalų sąnaudos vidutinių apkrovų zonoje bei 5 % mažesnės maksimalių apkrovų zonoje, iki 8 % didesnė CO koncentracija, taip pat nustatyta iki 26 % mažesnė bendra NOX koncentracija deginiuose įvedant maksimalų 13,0 g/min vandens garų kiekį VDV vidutinių apkrovų zonoje.Recently growing number of vehicles increases the amount of emitted pollutants into the atmosphere. This fact rushes the governments to tighten requirements for the ICE exhaust emissions. Some of the most harmful elements in the exhaust gases are nitrogen oxides NOX, which interact in the atmosphere and compose acidic compounds. However, presence of water in the combustion process reduces the concentration of pollutants in the exhaust gases. ICE fueled by water and fuel emulsions produces less NOX in the exhaust gases, but it adversely affects the fuel supply system. This study examined the effect of water on ICE diesel exhaust emissions. In order to avoid possible negative effects on fuel supply system and to simplify dosing, water is infused into the engine inlet tract in the form of vapor. Investigations were carried the engine operating without water vapor and with the introduction of water vapor into the engine inlet tract in three different concentrations. The research revealed that basic fuel consumption was 12 % higher in the average load area and 5% lower at the maximum load area. CO concentration was found to be up to 8 % higher, moreover total concentration of NOX was revealed to be 26 % lower in the exhaust gases entering the maximum 13,0 g/min of water vapor in the average load area.Žemės ūkio akademijaVytauto Didžiojo universiteta

The improvement of vehicle of agriculture of the work on transport

Vytauto Didžiojo universitetasŽemės ūkio akademij

Vandens garų kiekio įsiurbiamame ore įtaka dyzelinio variklio deginių emisijai

This paper examines the effect of water to diesel ICE exhaust emissions. In order to avoid possible negative effects of engine power supply system and for ease of dosing, water entered the engine inlet manifold in the form of vapor. Investigations were carried out without the engine running and the introduction of water vapor into the engine inlet tract in three different concentrations. Test were measured fuel consumption, carbon monoxide CO, and total nitrogen oxides NOX in exhaust gases. Tests found up to 26 % less than the total concentration of NOX in exhaust gases entering the maximum 13.0 g/min of water vapor content of the average load areaVytauto Didžiojo universitetasŽemės ūkio akademij

ENGINEERING FOR RURAL DEVELOPMENT PERFORMANCE OF 4 WD TRACTOR ON GRAVELED ROAD

Abstract. The distribution of the vertical loads of the axles and the air pressure in the front and rear tires have an influence on the kinematic discrepancy between the front and rear driving wheels during the exploitation of the 4 WD tractor. The kinematic discrepancy between the front and rear driving axle has an influence on fuel efficiency on the 4 WD driven tractors, too. The performance of 4 WD driven tractors during transport work on the graveled road is analyzed in this paper. The interaction of the different air pressure of the front and rear driving wheels with the road surface is analyzed in this paper. There are shown the results of the experimental investigation of the kinematic discrepancy influence on fuel efficiency during exploitation of the 4 WD driven tractor on the graveled road in this paper

The influence of the air pressure in the tires effect on fuel consumption of 4-wheeled driven tractor

Power distribution to the 4-wheeled driven vehicle effects fuel efficiency. The correct air pressure in the tires of the vehicle decreases the effect of power circulation in driveline system and determines the fuel efficiency of the vehicle. In this paper the driving wheels interaction on wheel–road surface is analysed, the air pressure in the tires effect on slippage and tractive force of the 4–wheeled agricultural vehicles. The effect on theoretical speeds of driving wheels with road surface is shown in this paper. This paper presents the results of experimental data obtained during exploitation of 4-wheeled driven tractor with different air pressure in the tires. There is shown the optional pressures in the tires in evaluation fuel efficiency in this paperVytauto Didžiojo universitetasŽemės ūkio akademij

How driving wheels of front-loaded tractor interact with the terrain depending on tire pressures

This paper analyzes peculiarities of wheel interaction with the terrain for 4WD tractors working with front-mounted loaders. When tractor wheels are loaded by a vertical forces that do not correspond to the specified proportions, deformations of front and rear tires also do not correspond to the specified proportions, and this leads to a kinematic discrepancy because of change in ratio between driving wheels’ rolling radiuses. In case of kinematic discrepancy, wheel slip/skid is taking place. In the paper test results are presented, how driving wheels’ slip/skid of 4WD tractors with front-mounted loaders depend on the vertical loads acting on the wheels and their tire inflation pressures. It was determined that there are dependences on relation between front and rear tire pressures, which allow avoiding wheel slip/skid for the 4WD tractor with front-mounted loader that runs without a load and transports loads. By preparing a tractor for work with front-mounted loader, it is advisable for operator to select a set of tires that would ensure the lead of front wheels lesser compared to the lead that is commonly used for traction works. In this case, the operator creates conditions for wheels’ interaction with the terrain without slip/skid at higher inflation pressures in the front tiresVytauto Didžiojo universitetasŽemės ūkio akademij

Air pressure in tires effects on slippage of tractors

Traction features of the tractor depend on the dynamic rates of the engine and transmission parameters. The traction features of the tractor depend greatly on the driving wheel exploitation characteristics, the physical-mechanical properties of the soil, and on the interaction of the driving wheels and the soil. By reference to the tests it was estimated that in the soil, if tractor wheels transmit driving force, they certainly slip. To reach maximum efficiency in production works, tractors are loaded by as high drawbar pull as possible. The consequence of it, quite often, is that the slippage of the driving wheels grows to the limit that is not allowed. There are various ways to reduce slippage. One way is to increase the contact area between the tires and the supporting surface. This is achieved by increasing the vertical wheel load and decreasing the pressure in the tires. There will be obtained the dependences between slippage and drawbar pull on various field conditions in this paper. When the tractor works by changing the drawbar pull, the distribution of vertical load on the front and rear axles changes, and it is difficult to set. This problem will be discussed in this article, tooVytauto Didžiojo universitetasŽemės ūkio akademij

Influence of inflation pressure in tires on traction ratio 2WD and 4WD driving modes of tractor

Cargo is transported not only on the roads but also at various field conditions. Tractors with trailers are mostly used on the field conditions. The tractor is loaded drawbar pull more when transporting a bigger cargo. On drawbar pull not only slippage of the tractor depends, but also vertical loads of the driving wheels of the tractor. It is recommended to decrease the inflation pressure in the tires in order to reduce slippage. The energy losses due to slippage can be significantly reduced by selecting the optimal inflation pressure in the tires. In order to properly select tractor trailers aggregates and choose 2WD or 4WD driving mode of the tractor suitable for the field conditions it is very important to predict the slippage value in advance. In such a case, traction ratio is usually used to predict slippage. The paper deals with the influence of the inflation pressure of the driving wheels on the traction ratio of the tractor. The drawbar pull influence of the vertical loads of the driving wheels of the tractor is analyzed. Also the slippage dependencies between the drawbar pull of the tractor and the traction ratio, when driving with 2WD and 4WD modes at various different inflation pressures in the tires, are presentedVytauto Didžiojo universitetasŽemės ūkio akademij

Performance of 4 WD tractor on graveled road

The distribution of the vertical loads of the axles and the air pressure in the front and rear tires have an influence on the kinematic discrepancy between the front and rear driving wheels during the exploitation of the 4 WD tractor. The kinematic discrepancy between the front and rear driving axle has an influence on fuel efficiency on the 4 WD driven tractors, too. The performance of 4 WD driven tractors during transport work on the graveled road is analyzed in this paper. The interaction of the different air pressure of the front and rear driving wheels with the road surface is analyzed in this paper. There are shown the results of the experimental investigation of the kinematic discrepancy influence on fuel efficiency during exploitation of the 4 WD driven tractor on the graveled road in this paperVytauto Didžiojo universitetasŽemės ūkio akademij