Determination of rolling radius of self-propelled machines' wheels

Abstract

The obtained results allow calculating the actual rolling radius of the wheel and evaluate the slipping of the drive wheels of self-propelled machines in accordance with the air pressure in the tires and the parameters of interaction with the support surface. On the basis of the developed model for determining the initial radius of the wheel and the length of the contact zone of the wheel with the support surface, the dependence for determining the actual radius of the wheel rolling was obtained. The studies have confirmed an increase in the actual rolling radius and a decrease in wheel slip with an increase in air pressure in the tires. For example, for the rear wheel of a tractor John Deere 7130 with an increase in pressure from 0.6 to 2.6 atm, an increase in the rolling radius by 21 mm and a decrease in the slip coefficient from 1.94 to 0.83% were observed. For the front wheel, when the pressure changed from 1 to 2 atm, the rolling radius increased by 7 mm and the wheel slip coefficient decreased from 1.76 to 1.12 %. The determination index of calculated and experimental values of the real rolling radius is η2 = 0.98 for the front and η2 = 0.99 for the rear wheels, which indicates the adequacy of the calculated dependences.