Traction characteristics of tires of various designs for the complete set of mobile propulsion devices of the fifth traction class

Background. Tire properties are the main factors determining traction and agricultural technological performance of wheeled mobile energy vehicles.

Purpose. The purpose of the research is to study the traction indicator efficiency of large-sized tires of various designs for equipping the running system of mobile power equipment of the fifth traction class.

Materials and methods. Traction efficiency, as a universal indicator of the operation efficiency of a wheeled mobile energy machine, is largely determined by the pneumatic tire design of a running system. Therefore, serial tires 30.5R-32 and 33R-32, tires with optimized shell reinforcement 30.5R-32M and 33R-32M, and tires of experimental (diagonal-parallel) design 33DP-32 were used as objects of research.

The research of tires designed for tractors’ driving wheels of the fifth traction class, in order to establish their traction and energy parameters, was carried out experimentally by testing them on a specially manufactured tire test bench.

Traction properties tests of tires (at various air pressures in them) were carried out on different supporting bases: concrete, stubble of grain ears, and a field for sowing.

Results’ confirmation was obtained during traction tests of the K-701M tractor when its running system was equipped with tested tires.

Results. As a result of the traction tests carried out on a tractor of the fifth traction class (K-701M), the undoubted advantage of installing tires with optimal internal reinforcement parameters on its driving wheels over equipping them with mass-produced tires was established.

All tires tested on a concrete base showed almost the same traction characteristics, but still the 30.5R-32M, 33R-32M and 33DP-32 tires had slightly higher values.

On stubble and in the field for sowing, the 30.5R-32M, 33R-32M and 33DP-32 tires showed a higher traction efficiency of 0.03 or more due to a decrease in slipping by 5...16% compared to the production ones. It should be noted that the 33R-32M and 33DP-32 tires have a noticeable advantage in traction performance at both agricultural ranges when setting a reduced intraperitoneal pressure, which is 0.11 and 0.09 MPa for them, respectively, on stubble and 0.09 and 0.07 MPa in the field for sowing.

Conclusion. It is proved that the K-701M tractor, which had upgraded and experimental tires installed on the driving wheels, showed a higher (from 7 to 19%) conditional traction efficiency compared to the complete set of its chassis system with serial tires.

It was found that the serial tires 30.5R-32 and 33R-32, when tested on a rigid support, showed almost the same traction efficiency. The best traction and energy performance on concrete was shown by the upgraded 33R-32M tires and, especially, the 33DP-32, which showed a traction efficiency of almost 0.84 due to slight slipping (3.2%).

At various agricultural farms, the serial tire 30.5R-32 demonstrated the lowest traction performance, while the diagonal-parallel tire 33DP-32 demonstrated the highest traction performance.