This publication presents the results of laboratory tests of idler rolling resistance under operational loads. Operational loads are understood as radial and axial forces acting on the idler, with values corresponding to those that occur in the conditions of its operation in copper ore mines. Knowing the rolling resistance is important not only at the stage of conveyor design, selection of the drive power or calculations of the necessary belt strength, but also when improving and searching for new idler design solutions. The idlers adopted for this research were differentiated in terms of bearings and idler axial clearance. The investigations were carried out on a unique test stand designed and built by the authors. The construction of the stand enables simulating operational loads while measuring the rolling resistance. The test rig measures idler bearing losses and rolling drag, not belt indentation rolling resistance. The object of the research were ø133×465 idlers, which are most commonly used in the raw materials industry. The results show the possibility of reducing the belt conveyor energy consumption by appropriate selection of the design features of the idler bearing unit.

The publication presents the evaluation of the effectiveness of belt tensioning systems based on the results of model laboratory tests. The types of tensioning devices most commonly used in industry were selected for testing: winch, gravity, pneumatic and follower. The evaluation of the efficiency of belt tensioning devices is complex, as the tensioning system is not autonomous and is only part of the belt conveyor equipment. Therefore, the publication presents the impact of belt tension force on the durability of basic conveyor components such as the belt and its joints, and drums. The characteristics of the tested belt tensioning devices are presented and the construction and research capabilities of the laboratory model of the belt conveyor are described. Measuring systems mounted on the conveyor are described in detail, enabling recording of variable conveyor operating conditions, measuring belt speed, driving force and belt stress. The results of the research are the experimental static characteristics of the most commonly used tensioning devices, which show the relationship between the drive moment and the belt tensioning force. Obtained characteristics will allow the development of guidelines for the design and selection of the most effective belt tensioning devices.

The publication presents the results of measurements of the operating parameters of the drum drive of a belt conveyor operating in a copper ore mine. The laboratory and industrial tests of belt conveyor components so far have largely focused on idler sets, the belt and the conveyor route. The authors of the publication notice that the subject literature lacks information on research into the coefficient of friction between the belt and the drum in an industrial facility under real conditions, which may imply that the phenomenon of driving force transmission from the drum surface to the belt has not been thoroughly explored. The investigations described in the publication were aimed at determining the kinetic coefficient of friction between the conveyor belt and the lining of the drive drum under operating conditions. In the first part of the study, preliminary laboratory tests were carried out, whereas in the second part of the study, a mobile, non-invasive measurement system was applied, which allowed for recording the kinematic and dynamic parameters of the conveyor’s operation. During the several dozen minutes of the conveyor’s operation, there were several start-ups and brakings as well as periods of steady operation under variable load on the material handled. The non-typical planned sequence of switching on the drive motors caused a temporary slip of the belt on the drive drum surface during one of the start-ups. The recorded parameters of the conveyor operation enabled determining the operational limit value of the friction coefficient between the belt and the lining of the drive drum.

The publication presents the construction of the station for testing the friction coefficient under high pressure and low slip velocity values. These conditions of cooperation of friction pairs occur in the drives of transport machines such as belt conveyors and suspended monorails. The value of the friction coefficient, depending on the operating conditions such as moisture and rock or coal dust pollution, has a significant impact on the correct and efficient operation of such drives. The features of the station allow mapping the operating conditions on a laboratory scale. As part of the research, appropriate friction samples made of rubber or polyurethane were prepared. Referring to the conditions of conveyor operation and conditions of contact of the conveyor belt with the drive drum, the values of unit pressures and values of slip speed occurring in the drum drive of the belt conveyor were determined. A series of laboratory tests were carried out for the friction pair rubber drum lining – conveyor belt cover. The tests were carried out for four different states of friction vapor surfaces, namely for dry and wet samples, as well as for samples in clean or contaminated with stone dust. As a result of the tests, the values of friction coefficients for various surface states were determined, which will be valuable information for designers of friction drive systems of transport devices.

One of the components that affects the energy consumption of belt conveyors is the rotational resistance of the rollers. In real conditions, the roller is subjected to loads not only radial but also axial, resulting from its cooperation with the belt and the way of installation on the conveyor. Knowledge of these resistances is important not only in the design of conveyors, but also in the improvement and search for new structural solutions of the rollers. The article presents an innovative stand dedicated to the study of rotational resistance of the rollers under operating load, its research capabilities and the results of preliminary tests.