Verschleißsimulation grenz- und mischreibungsbehafteter Wälzkontakte

This contribution presents an approach for the numerical wear calculation of rolling/sliding-contacts. The finite element method based simulation model of Winkler [1] is extended to include contacts subject to boundary lubrication in addition to contacts subject to mixed lubrication. Using the example of an axial cylindrical roller bearing and two load cases, wear-modeling results of the mixed and boundary lubrication regime are illustrated.

Tribological behavior of grooves textured thrust cylindrical roller bearings under dry wear

To prolong the serve life of roller element bearings (REB) and improve the reliability of mechanical system, the tribological behavior of the “washers-cage-rollers” system of grooves textured thrust cylindrical roller bearings (TCRB, 81107TN) under dry wear was researched. The pattern parameters include: width of grooves (WOG, 50, 100, and 150 μm), depth of grooves (DPOG, 7, 11, and 15 μm), as well as groove deflection angle (GDA, 0°, 45°, 90°, and 135°). The influence mechanism of grooves on the tribological properties of REBs is discussed. The results show that: As the GDA is 45°, the coefficient of friction (COF) and mass loss of bearing is the lowest among four angles. The average COFs of grooves textured bearings are much higher than that of smooth one, and their mass losses are all lower than that of smooth bearing. The influence of pattern parameters on the surface stresses of grooves textured bearings is weak. In this work, when the WOG is 50 μm and the DPOG is 7 μm, the wear loss of grooves textured bearing is the lowest, reduced by up to 75.6%. This work can provide a valuable reference for the raceway design and optimization of REBs.

Working in of roller ends and bars of cylindrical roller bearings at combined radial and axial loads

The paper investigates the influence of the process of running-in the ends of rollers and sides of cylindrical roller bearings on the conditions of hydrodynamic contact of these parts: the formation of an oil film and friction. For this purpose, the results of finite element modeling of the stress-strain state of the bearing parts in contact: the inner ring, the side flange and a fragment of the axle of the wheelset, and the multi-mass simulation of the dynamics of the bearing operation are used. The influence of the yaw angle of the roller on the size and shape of the contact area on the side is investigated. The dependences for calculating the thickness of the oil film in the contact between the ends of the rollers and the flanges of the bearing rings are being refined, which now make it possible to take into account the misaligned position of these parts during their force interaction. The results are illustrated using the example of a roller bearing of standard size 232926.

Effect of vein-bionic surface textures on the tribological behavior of cylindrical roller thrust bearing under starved lubrication

To reveal the effect of vein-bionic surface textures on the tribological behavior of cylindrical roller thrust bearings (CRTBs) under starved lubrication, six kinds of leaves (Forsythia, Clausena lansiu, Ash, Purple leaf plum, Pipal and Apricot) were chose and their simplified patterns were fabricated on the shaft washers of CRTBs using laser surface texturing. The coefficients of friction (COFs) of vein-bionic textured bearings were measured using a vertical universal wear test rig. Their mass losses and worn surfaces were also characterized. The results show that: There is important influence of the symmetry of vein-bionic textures and the number of secondary veins on the friction and wear properties of vein-bionic textured CRTBs under starved lubrication. Compared to the smooth group, the COFs and mass losses of vein-bionic textured bearings are all reduced. Among all groups, the tribological performance of bearings with a pattern inspired from Ash is the best. Its wear loss is reduced by 16.23% and its COF is reduced by 15.79%. This work would provide a valuable reference for the raceway design and optimization of roller rolling element bearings.

Structures Dynamic Property Analysis of Elastic Composite Cylindrical Rolling Element

Elastic composite cylindrical roller bearing is a novel type of roller bearing whose rolling element is designed by innovating the rolling element structure of cylindrical roller bearings. For the purpose of investigating the dynamic properties of the rolling elements with different structural parameters and solving the modes of elastic composite cylindrical rolling element with different filling degrees, first, this study compares elastic composite cylindrical rolling element to solid cylindrical rolling element, in terms of natural frequency and vibration mode. Next, the integration time step is determined, based on the natural frequency of the vibration in the Y direction, the response of various rolling element, under impact loads, is solved. Furthermore, the laws of the energy changes and nodal displacement variations of rolling element are explored, at different filling degrees. Finally, adopting the decay method, the damping ratio of elastic composite cylindrical rolling element, under different structural parameters and external loads, is calculated. According to the results, with the increase of filling degree, the natural frequencies of various orders of elastic composite cylindrical rolling element gradually declined. The damping ratio of rolling elements decreased, as the filling degree increased, while it could be changed by adjusting the structural dimensions of rolling elements. The analysis results of this study provide some theoretical reference for studies on the parameter optimization of rolling element structures, the vibration and noise reduction of elastic composite cylindrical roller bearings.