Energetic efficiency of an agricultural tractor in function of tire inflation pressure

The tire inflation pressure, among other factors, determines the efficiency in which a tractor can exert traction. It was studied the effect of using two tire inflation pressures, 110.4 kPa in the front and rear wheels, 124.2 kPa in the front wheel and 138 kPa in the rear wheels, the energetic efficiency of an agricultural tractor of 147 kW of engine power, in the displacement speed of 6.0 km.h-1, on track with firm surface, with the tractor engine speed of 2000 rpm. For each condition of the tire pressure, the tested tractor was subjected to constant forces in the drawbar of 45 kN and 50 kN, covering 30 meters. It was used a randomized complete block with a 2x2 factorial arrangement (tire pressure and drawbar power) with four replications, totaling 16 experimental units. Data were subjected to analysis of variance, using the Tukey test at 5% probability for comparison averages. The lowest hourly and specific fuel consumption, the lowest slippage of the wheelsets and the highest efficiency in the drawbar was obtained with the tire inflation pressure of 110.4 kPa in the front and rear tires of the tractor, highlighting that lower pressures improve energetic and operational performance of the tractor.

Tractor perfomance as a function of speed and seeder s tire inflation pressure

O desempenho de tratores agrícolas em condições de campo resulta da interação entre pneu e rodado, influenciado pela velocidade de deslocamento. O objetivo deste trabalho foi avaliar o desempenho de um trator agrícola sob diferentes pressões de inflação dos pneus da semeadora (518, 483, and 414kPa) e em duas marchas que proporcionaram velocidades de 3,0 e 6,0km h-1. O experimento foi realizado no campus de Jaboticabal da Universidade Estadual Paulista (UNESP). O delineamento experimental utilizado foi fatorial inteiramente casualizado (3x2), com quatro repetições. A força de tração foi influenciada pela marcha e pela potência exigida; no entanto, a pressão de inflação do pneu da semeadora não alterou esses parâmetros. Além disso, o consumo de combustível foi influenciado apenas pela marcha do trator. O consumo de energia foi maior com o aumento da velocidade, ocasionada pela mudança de marcha. A velocidade de deslocamento foi maior para a pressão de 518kPa, em razão da menor patinagem da semeadora promovida por essa pressão. A patinagem do trator não foi alterada pelos fatores testados.

Experimental investigation of truck tire inflation pressure on pavement-tire contact area and pressure distribution. Interim report.

Texas State Department of Highways and Public Transportation, Transportation Planning Division, Austin

Effects of load, inflation pressure and tire deflection on truck tire noise levels. Final report.

Transportation Department, Office of Noise Abatement, Washington, D.C.

Development of new concepts in low tire pressure warning devices. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Feasibility of automating truck tire pressure data collection. Final report.

Texas State Department of Highways and Public Transportation, Austin

Proof pressure evaluation of worn passenger car tire carcasses. Final report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Procedures for controlling the effect of increased tire pressure on asphalt concrete pavement damage. Final report.

Oregon Department of Transportation, Salem

Pressure effects on worn passenger car tire carcasses. Final report.

Transportation Systems Center, Cambridge, Mass.

An evaluation of existing tire pressure monitoring systems.

Mode of access: Internet.

Rolling resistance of tires measured under transient and equilibrium conditions on Calspan's tire research. Final report.

Transportation Department, Office of the Assistant Secretary for Systems Development and Technology, Washington, D.C.

Passenger vehicle tire inspection equipment development. Volume I - summary report.

National Highway Traffic Safety Administration, Washington, D.C.

Passenger vehicle tire inspection equipment development. Volume II - technical report. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Passenger tire use survey. Consolidated report.

National Bureau of Standards, Office of Vehicle Systems Research, Washington, D.C.

Tire use survey; interim report based upon summer observations.

National Bureau of Standards, Office of Vehicle Systems Research, Washington, D.C.