Power circulation in driveline system when the wheels of tractor and trailer are driven

In off-road “tractor–trailer” vehicle combinations, the trailer can be equipped with one or more driving wheels. The distinguishing feature of vehicles with two or more driving axles is distribution of total power between the driving wheels. In machines with several driving axles, kinematic mismatch between theoretical wheel speeds nearly always takes place. The wheels of tractor and trailer can slip uniformly and differently, some of them may even slide. It is unfortunate when the wheels slide, as power circulation takes place. In this paper, power circulation of a vehicle composed of a tractor and trailer having driving wheels and driving wheels’ interaction with soil is investigated. The conclusion is that in a vehicle composed of two machines having two driven axles each, circulation of power can be avoided or reduced by turning off one driving axle in the machine, which delivers more power and has advancing driving wheels

Investigation of tractor engine power and economical working conditions utilization during transport operation

Article analyzes tractor working and its engine conditions from economical point of view. Overview of tractor wheel slippage reliance on the traction force and weight utilization coefficient is given. Tractor maximum driving force according to road and field conditions, and driving speed are submitted. Literature and theoretical investigation analysis is done, where interaction between tractor wheels made‐up driving force and grip is analysed. Driving speed and driving force dependence on rolling resistance and total aggregate weight using nominal power is described. In the present experimental research reduction in fuel consumption of tractor transport aggregate by reducing engine speed and by keeping the same work speed, was determined. First published online: 27 Oct 201

Tractor’s engine efficiency and exhaust emissions’ research in drilling work

Tis paper provides an overview of possibilities for determining tractor’s engine load, fuel consumption and exhaust emissions in real operating conditions. Theuse of accumulated database in tractor’s electronic control modules for the analysis of engine load, fuel consumption and exhaust emissions is analysed. The methodology for analysis of engine power, speed and exhaust emissions’ dependencies, also for analysis of engine exhaust emissions is presented. Tis paper presents testing results of the unit combined of tractor “Massey Ferguson MF 6499” and drilling machine “Vaderstad Rapid” by engine load, fuel consumption and exhaust emissions. Drilling process time, engine load, fuel consumption and exhaust emission components’ distribution are presented in different engine speed and cyclic fuel injection modes. Test results are analysed separately for technological drilling and work processes at the headland. In the technological process of drilling, if the tractor engine speed and, correspondingly, the transmission gear ratio were reduced to get the set working speed, fuel consumption decreased, CO and CO2  emissions varied slightly, but the NOx  increased significantly. Significant part of exhaust emissions occurred at headlands. The conclusion is that the fuel consumption and exhaust emissions, including harmful components, can be reduced only by complex optimization of technological processes and tractor operating modes. First published online: 19 Mar 201

The slippage of the driving wheels of a tractor in a cultivated soil and stubble

The article analyses the relation between the slippage of driving wheels and the traction characteristics of a tractor. The indicators for estimating wheel slippage are a coefficient of tractor weight force utilization for driving wheel grip and a coefficient of the ratio of trailer and tractor mass. The dependencies of wheel slippage on the weight utilization coefficient of tractors and the ratio of trailer and tractor mass are overviewed. The presented and carried out analysis of the equations of weight utilization coefficient ϕ g determined its dependencies on rolling resistance coefficients f of a means of transport, working speed v and acceleration aon the mass ratio of a trailer and tractor mp/mt . The results of experimental research on acceleration and constant speed regimes in a cultivated soil and stubble are presented. The dependencies of slippage on the ratio of trailer and tractor mass and the weight utilisation coefficient of a tractor and trailer are viewed. First published online: 27 Oct 201

Tractor engine load and fuel consumption in road construction works

Tractor load influences engine work parameters having an influence on the working economy and productivity of the complete tractor aggregate. The operational economy and productivity of the tractor is mostly evident when its engine power is utilized at least at 80% and engine speed is as low as possible. The paper analyses the engine parameters of tractor Massey Ferguson MF 8480 during the operational period of road construction works. Control tests on the parameters of the engine load of the tractor engine in combination with the employed milling equipment WS 2500 produced by the company ‘Wirtgen’ were performed. The study was carried out using engine load tables and graphs collected and stored in the so called ECU Load Profileintegrated in Electronic Engine Control Units. Theoretical analysis was made and an equation presented to establish the relation between engine power, engine speed and the quantities of cyclic fuel consumption. The study results present the distribution graphs of work time and fuel consumption at different engine speed during the operational period. The paper also indicates engine load and fuel consumption graphs of the tractor in combination with milling equipment. The article has also disclosed that the analysis of engine speed and load modes using information obtained from tractor‐integrated digital microprocessors reveals the operation quality of the tractor. First published online: 10 Feb 201

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

Bunkerio iškrovimo, stumdant iškrovimo sraigės gaubtus, teorinis pagrindimas

Santr. angl., rusBibliogr.: p. 222 (6 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij

Traktoriai su automatinėm pavarom Lamborghini firmos mašinos

Vytauto Didžiojo universitetasŽemės ūkio akademij

Traktorių su bepakopėmis transmisijomis palyginimas

Vytauto Didžiojo universitetasŽemės ūkio akademij

Lamborghini traktorių rezonansinės įsiurbimo sistemos varikliai (Rise)

Vytauto Didžiojo universitetasŽemės ūkio akademij