Jerzy Jackowski

Analysis of Rolling Resistance of Tires with Run Flat Insert

Run flat properties are required for tires intended for special applications like military or rescue vehicles. Run-Flat inserts make possible to drive a car or truck, with certain restrictions, also when inflation pressure is very low or non-existing (after tire damage). Rolling resistance of tires rolling on the inserts increases considerably in relation to the rolling resistance of properly inflated tires. This paper presents results of rolling resistance measurements for such conditions.

RESEARCH ON OPERATIONAL CHARACTERISTICS OF TYRES WITH RUN FLAT INSERT

The paper describes results of research on heavy vehicle tyre with Run Flat VFI insert. The experiment has included the determination of heat generation, rolling resistanceand radial stifnessof two different tyre designes (textile and steel carcass). The results have been used for the purpose of ewalution of tyre operating characteristics. The study included research on non-inflated tyre properties. The purpose of the paper is nto determine chracteristics of the tyres equipped with inserts, which are essenical for driving wheeled APCs. The inserts are composed of polymer rings mounted on rims inside the tyres. If the inflation pressure of the tyres is very low or of there is no inflation pressure at all, the rings transfers the loads imposed on the tyre to the run. Usually in such a case, there is coctact of the ring and inn er surdace of the tyre tread area. Laboratory facility for surveys of heavy vehicles tyres summary characteristicsof radial stiffness and histeresis of the tyres, temperature destribution on the external surface of the test tyre, comparison of radial characteristics of the tyres tested, example of stiffness characteristics, destribution of the temperature on the side of tyre during the road test and carcass damages on the flat tyre are presented in the paper.