Parâmetros de desempenho de tratores agrícolas de pneus comercializados no Brasil

• Autor(a) principal: Rinaldi, Paula Cristina Natalino
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/763
• topic: Ensaios; Tristones; Potência; Tração; Trials; Power; Traction; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA

Brazilian agricultural mechanization has had its great development since 1959, with the manual and semi-mechanized work gradually being replaced by mechanized, reaching today a high level of mechanization. In Brazil today, beyond there is no mandatory testing center, there are few studies aiming to determine the performance of agricultural tractors. Performance tests of the specimens are made by manufacturers, and because the official reports disclosure is not required, consumers have information only from the own manufacturer. Thus, this study aimed to evaluate the performance parameters of the agricultural tractors with manufactured and/or sold tires in Brazil in relation to power ranges and type of traction, through manufacturers consultation about the technical specifications, reports of previous tests, and measurements "in loco" of some specimens, assuming that a detailed analysis of the informations contained in the technical specifications and measurements of certain characteristics could enable the analysis of the real potential of each tractor model. To do so, from 191 agricultural tractors with marketed tires in Brazil, from July 2010 to July 2011, we calculated the following parameters, available thermal design power (TDP) and in drawbar (DB), torque, relative tractor weight/engine power, maximum traction force at DB; relative traction force/weight, traction yield, weight transfer, traction coefficient, operating slope, hourly consumption of fuel, fuel autonomy, specific fuel consumption, and thermomechanical performance. Some of these parameters were evaluated under different soil and ballast conditions. The results showed that the power range IV and 4x2 TDA traction type present the best values for available powers, torque reserve, and estimated maximum traction power; tractors in the power range III and 4x2 TDA traction type have the capacity to work in higher slopes; and hourly and specific fuel consumption is lower for 4x2 tractors in the power range I. It can be concluded that tractors models of range II and 4x2 TDA traction type have greater representation in the national market. Among the studied parameters, the best performance was recorded for the tractor of range III and IV and 4x2 traction type, and the used methodology has been effective to determine the tractors performance parameters