DETERMINATION OF ROLLING RADIUS AND SLIP OF WHEELS OF SELF-PROPELLED MACHINES

• Main Authors: G. Golub, S. Kukharets, V. Chuba, A. Zabrodskyi
• Format: Article
• Language: English
• Published: Zhytomyr National Agroecological University 2019-09-01
• Series: Наукові горизонти
• Subjects: rolling wheel radius; slipping; wheel deformation; air pressure in the tire; wheel contact area with bearing surface.
• Online Access: http://journal.znau.edu.ua/horizons/article/view/289/286

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 obtained results allow estimating the effect of wheel deformation under the influence of vertical load (the weight of the power unit) on the actual wheel rolling radius and the slipping coefficient. As far as the vertical load is constant, than the actual rolling radius and the slipping coefficient while wheel rolling can be taken for the initial state of the wheel. 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 index of determination 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. The high level of coincidence between the calculated and experimental values of the actual wheel radii and wheel slipping coefficients indicates the adequacy of the developed methods and dependencies for practical application.