农用拖拉机动力换挡变速器功率损失的试验研究

Experimental Study of Power Loss in Power-shift Agricultural Tractor Transmission

通过对140 kW农用拖拉机上使用的全动力换挡变速器在不同挡位下的功率损失试验研究,找出了拖拉机较高功率损失的工作挡位,并确定燃油消耗的原因。在传动装置运转的情况下进行试验,并对各挡位所吸收的功率进行了计算分析。在识别出测量的有较高功率损耗的挡位之后,将变速器的零部件拆开,分析测量功率损耗的影响。试验结果表明,在较高的挡位上功率损失较大,空挡位置的被动阻力和摩擦以及液压回路吸收的功率占总损失的52%,变速器中溅出的油占总损失的40%,制动占了4%,最终减速器和对应的太阳轮占了4%。

The results of tests on a full power-shift transmission,suitable for use on a 140 kW,agricultural tractor are reported.The aims of the research are to evaluate the working conditions where there are higher power losses,and to identify the causes of energy dissipation.The tests were carried out with the transmission set in motion and the power absorbed in each gear position was evaluated.Following identification of the gear position in which the higher losses were measured,the components were separated,one at a time,from the transmission,and the influence on the losses was measured.The results show that higher losses occur in higher gear position.The tests indicate that 52%of the total losses are caused by passive resistance and friction in the transmission together with the power absorbed by the hydraulic circuit in the neutral position,40%by oil splashes in the transmission,4%by the brake,and 4%by the final reducer and corresponding sun wheels.