Experimental evaluation of traction properties of ultra-low pressure tires

Abstract

Nowadays, mobile power vehicles (MPV) equipped with ultra-low pressure tires are widely used in agriculture when conducting field work in the early spring. For these power vehicles the funda-mentally new wide-profile tires with low load capacity were developed. Its features are ultra-low intra-tire pressure (10-80 kPa), increased profile width, low ply rating (2-4), high elasticity and soil-covering tread, which in turn provide the necessary traction qualities. Due to the high elasticity of these tires and the relative radial deflection (up to 25 %), the contact area of the tire with the soil increases and the specific pressure decreases. It was determined that due to the cost parameters, a wide range of ultra-low pressure tires, as well as specific features of the tests, they remain insuffi-ciently studied at the moment. In this regard, authors conducted bench tests and determined the basic and traction characteristics of the ultra-low pressure tire with a dimension of 1020×420-18 of Bel-79 model. The equations for the dependence of tire performance on various factors were de-rived. It was found out that when driving on a concrete supporting base, the traction properties of the tire improve with the increase of the internal pressure of the tire and the load on the wheel, but when driving on the field prepared for sowing, the improvement of support-coupling indicators is observed with a decrease of the internal pressure of the tire and the load on a wheel. It was noted that the results of the tests can be used as reliable initial data for the development of mathematical models of the movement of various mobile power vehicles equipped with ultra-low pressure tires.

Estimation of energy consumption for rolling a mobile vehicle equipped with ultra-low-pressure tires

“…9). This behavior of the tire can be confirmed by the data obtained in [19]. An increase in the load on the tire in this pressure range is highly undesirable, as it will lead to a decrease in the tire life.…”

“…In the course of the experiment, the required air pressure PW was set in the tire and with the help of a movable carriage of the stand it was pressed against the support base with force GZ. Based on the data obtained in [18], for each value of the radial load, the optimal value of the traction force was determined, at which the tire implements the maximum propulsive efficiency. The traction load was created using a system of stacked weights connected to the movable table of the stand by a cable through a system of blocks.…”