The paper presents the methodology for designing the teeth conjunction of planetary gears in the planetary roller screw mechanism. A function of the planetary gears is to synchronize an operation of rollers in order to avoid axial displacements. A condition of the correct operation is no axial movement of rollers in relation to the nut. The planetary gears are integral parts of rollers and therefore an operation of the gear transmissions has a direct impact on cooperation of the screw, rollers and the nut. The proper design of gear engagements is essential for reducing slippage on surfaces of the cooperating threaded elements. For this purpose, in a designing method, both the limitations of operation and kinematic conditions of rollers’ operation have to be taken into account.

Additional motor vibrations are the result of a faulty bearing. They are reflected in the harmonic content of stator currents. The object of the investigation presented in the paper are measurements related to diagnostics of induction motors, especially damages caused to bearings. Due to the fact that the amplitude of the network voltage basic harmonic in the current spectrum is high in comparison with components responsible for damages of bearings, preliminary elimination of this component from the analog current signal has been proposed.

The problem with interpretation of diagnostic measurements in present systems is the difference between measurement results of characteristic frequencies and theoretical calculations.

In the proposed measurement system this problem was solved in such a way that the value of the angular speed and of the supply frequency is calculated on the basis of appropriate components in the very same current spectrum that is further used in the search for diagnostic components.

The paper presents also the measuring system and provides results of the investigations carried out on a motor encumbered with a specially prepared defect.

Technical system for condition monitoring and failure diagnostics of gear driver with roller bearings was tested in situ. The experimental measurement data of rotors shaft vibration displacements were introduced into physical model of gear teeth meshing dynamics. The modelling and simulation of teeth failures in gear driver with roller bearings was performed by finite element method. The experimental and simulation results were used in identification and elimination of sources of gear teeth damages and bearings failures.

In the paper, the authors present the solution aimed at increasing reliability of the conveyor units. The analysis of technological and operational defects of conveyor rollers is presented. The changes in manufacturing technology have been proposed, which allowed for avoiding welding and provided the required level of tightness.

Computer simulation of the motion of air in the labyrinth seal of the roller was conducted to determine the numerical parameters of possible airflows. It is proved that the airflow is present in the gap of the labyrinth seal due to the roller rotation. It is shown that the reason for the penetration of abrasive particles through the labyrinth seal after stopping is decompression, which occurred as a result of temperature change and push out of airflows during rotation. It is also suggested that the number of stops during the operation should be taken into account when determining the durability of rollers. Practical recommendations are given for preventing the penetration of abrasive particles during conveyor stops and the need for combined seals. The results can be used for the construction of roller conveyor belts in any industry.