The aim of this study was to carry out the investigation and analysis of two-stage magnetic precession gear dynamics and the determination of the resonance frequencies, which can be a cause of the powertrain system failures. Graphical interpretation of the two-stage precession gear is presented, and two equations of the dynamics of the movable elements of the presented gearbox were determined. On the basis of these equations, the stiffness coefficients and resonance frequencies of the presented gearbox were mathematically derived. The next step was to develop a numerical model of the magnetic precession gear dynamics in the environment of MATLAB Simulink. The elaborated model allowed us to analyze the influence of varying the input speed and the load torque on the operation of the magnetic precession gear. The performed analyses of the dynamics of the magnetic precession gear showed the occurrence of a resonance phenomenon under the influence of load torque ripples with a frequency close to the natural frequency of the studied system.

Lubrication is a critical aspect of the metal forming process and it is strongly influenced by the surface texture of the tool-forming surfaces. This study is focused on determining the effect of surface finish and heat treatment on wettability involving commonly used lubrication agents. Three different finishing states are evaluated (as-ground, as-polished and as-nitrided). Surface topography was measured using a focus variation microscope. Parametric evaluation was carried out according to ISO 25178, including fractal methods. The functional relations between the finish state and wettability, lubricating agent and wettability, selected surface parameters and wettability, as well as between finish state and selected surface parameters, were designated. The results showed that surface finishing treatments, particularly nitriding, influenced both surface roughness and wettability, with varying effects observed across different lubricants and droplet sizes. The findings provide valuable insights into the optimization of lubrication strategies for metal forming processes, highlighting the importance of tailored surface treatments for enhanced tool performance and longevity.

Gears are common and important components of many types of propulsion systems applied in mechanical engineering. The aim of this paper is to present the mechanical design and performance analysis of a novel two-stage magnetic precession gear (MPG). The main advantage of the proposed design is the ability to obtain higher transmission ratios than other currently known magnetic gear types. A detailed analysis of the performance of the MPG was carried out employing a developed numerical model of the magnetic field in the proposed gear. The MPG model is based on the finite element method (FEM) and allows determining the relations between the torque acting on the main components of the gear, load angles, and air-gap lengths. To validate the developed FEM model, the prototype of an MPG with a 1/144 gear ratio was built and tested. The experiments were also focused on determining the mechanical efficiency as well as the influence of rotational speed and lengths of air gaps on the maximum load torque. The tests indicated that the maximum efficiency of the studied MPG is about 30%, which is comparable to the efficiency of mechanical two-stage precession gears with face meshing.

The paper presents the theoretical bases, design and the principle of operation of two-stage precession type transmission with face meshing. Description and the principle of forming the face meshing which is modified by the original method have been shown as well. Dimensional relations between particular components of the gears are established and the analysis of optimal gear ratio, depending on the number of teeth or magnets on the circumferences of meshing gear wheels is also provided in the paper. For further analysis four prototypes of mechanical precession transmission with face meshing were designed, built and investigated. Those prototypes present different sizes, reduction ratio and precession angle. Investigations, described in the paper, helped to determine the gear efficiency rate as well as the maximal torque that could be transferred for the given rotary speed. This paper presents also the conception of the design of a novel double stage precession magnetic gear with face neodymium magnets. The results of the initial studies are the background of the further research in the field of magnetic precession type transmission.

The paper shows an idea of a new type of mechanical gear — the eccentric rolling transmission. The main parts of that transmission are rolling bearings, mounted eccentrically on the input shaft which cooperate with the special-shaped cam wheels mounted on the output shaft. The number of rolling bearings is equal to the number of cam wheels. On the basis of kinematic analysis equations of the curve which describe a shape of cam wheels were determined for two different cases: in the first one the directions of shafts rotations were opposite, and in the second they were the same. Kinematic analysis of the novel transmission was carried out to determine maximum gear ratio depending on the adopted input parameters. As a result of analyses a design procedure of the eccentric rolling transmission and CAD model were prepared.