Cylindrical Roller Bearings Research Articles

Dynamic modelling of combination imperfects of a cylindrical roller bearing

Local fault failures could greatly affect the vibrations of cylindrical roller bearings (CRBs). However, most previous works defined the fault surface as the smooth ones, whose actual roughness features were ignored. To overcome this problem, this study presents a time-varying stiffness excitation model for a CRB including a local fault with the roughness surface based on Greenwood and Williamson’s method. A dynamic model with the time-varying stiffness excitation model is developed to analyze the effects of the roughness and local fault on the contact features and vibrations of CRB. The changes of time-domain contact features and vibrations for defective CRB with and without the roughness surface are analyzed. Note that the roughness surface can greatly affect the contact stiffness, contact deformation, and vibrations for CRB under a small force. But its effect will decrease with the increment of radial load, which will close the value of smooth CRB. This paper can show some guidance for CRBs including the local faults with the roughness surface.

Dynamic analysis and frequency response of cylindrical roller bearing of an airflow root blower

Dynamic analysis and frequency response of cylindrical roller bearing of an airflow root blower

Analisa Keputusan Penerapan Preventive Maintenance Pada Boyd Crusher di Perusahaan Penunjang Industri Pertambangan

Mining industry has the closed relation which is not separated from some types of company. Those service company are very important for mining activities. The support company is a company who give service for making the mining activities run well. Research or analysis service for solid or water mineral content is one of the support companies as state above. The purpose of this research is to know the often damage of spare parts of Boyd Crusher as one of main equipment of service company above. In this case, the coefficient value of the form and the time parameter must be known by using Weibull distribution, so that the maintenance method can be decided by applicating preventive maintenance concept. This research is done by using quantitative – qualitative method which based data around 1 year and the result is found that the Cylindrical Roller Bearing is the highest damage component. This finding is continued to be analysed by using fish bone diagram to know the main factor of those damages and the result is the less of routine lubrication and Lubricant excessive quantity for that component part where this part is made from metal material that has high friction.

Ranking and selection of optimum alternatives based on linear scale transformation for cylindrical roller bearing

Bearing is the most precautious element in rotating machinery. Defects produced in any part of the bearing may lead to a hazardous environment that increases the noise and vibration. It can be diminished with appropriate loading combinations. The selection of optimum loading conditions requires developing an algorithm. Multiple Attribute Decision Making (MADM) techniques are utilized to pick up a unique and ideal solution or ranking of choices from the available alternatives. The MADM techniques have not been used for bearing fault diagnosis so far. This paper offers a novel methodology for the Ranking and Selection of Optimum Alternative based on Linear Scale Transformation (RSOA-LST), having combined benefit and cost criteria that rank the choices and determine the percentage influence of various alternatives. This methodology has been performed with several experimental signals of cylindrical roller bearing, acquired from twenty-four bearing conditions having several speeds and loading combinations. The normalization of attributes (statistical features) considering combined benefit-cost criteria, mean of various parameters (speeds, attributes, and bearing conditions), and Percentage Influencing (PI) are intended simultaneously to obtain the ranking of alternatives (loading conditions). Local Defect Analysis (LDA) and Global Defect Analysis (GDA) are carried out in this research. In LDA, the ranking of alternatives based on the PI for each defect and the ranking of bearings based on fluctuation in PI of various alternatives are attained. In GDA, the sequence of alternatives is obtained globally. The effectiveness of the suggested methodology has been verified over other MADM techniques. The outcomes state that the suggested technique effectively bifurcates the influence of alternatives locally as well as globally over other techniques.

Design, manufacturing, and performance evaluation of a novel smart roller bearing equipped with shape memory alloy wires

In this study, a new type of seismic isolation device, called shape memory alloy (SMA) wire-based roller bearing (SMA-RB) is developed and introduced. The SMA-RB has been designed, manufactured, and experimentally tested. This bearing consists of cylindrical roller bearings and SMA wires with straight or cross configurations, as supplementary damping elements. In such a smart bearing, the superelastic (SE) SMA wires are passed through the hooks/pulleys attached to the supporting plates of the bearings in different configurations. The rollers provide lateral flexibility, and SMA wires supply energy dissipation and self-centering (SC) properties. In the manufacturing stage, a new mechanism for coupling wires (i.e. SMA wire joiner/coupler) is proposed. The results show that SMA wires, made of nickle titanium (NiTi), provide a SC damping mechanism with almost zero residual deformation which can effectively control the device from over-displacement. While using pulleys and newly designed wire joiners in the SMA-RB, the bearing can experience a stable cyclic behavior. Since the rollers generate a negligible amount of frictional force, the SE NiTi wires with a flag-shaped hysteresis mainly contribute to the overall shear hysteretic response of the SMA-RB. A triangular-shaped constitutive model can be used to accurately describe the hysteretic behavior of SMA-RB with different wire configurations.

Study on contact load and preload characteristics of cylindrical roller bearings with triple-lobe raceway

The suitable preload design of cylindrical roller bearing with triple-lobe raceway can avoid effectively bearing sliding damage. To realize the preload characteristics analysis of bearing, the quasi-static numerical model of cylindrical roller bearing with triple-lobe raceway is established and solved by the improved Newton-Raphson method. Taking a cylindrical roller bearing with triple-lobe raceway as an example, the effects of mounting radial clearance, outer raceway waveform value, radial load and rotational speed on maximum contact load and preload of the bearing are analyzed. The results show that the preload of cylindrical roller bearing with triple-lobe raceway can be controlled by adjusting the mounting radial clearance and outer triple-lobe raceway waveform value according to the radial load and rotational speed conditions. The bearing temperature trend predicted by the preload characteristic is verified by the test. It indicates the numerical model can effectively guide the preload quantitative design of cylindrical roller bearing with triple-lobe raceway.

Ограниченные цилиндрическим отбойником изгибные колебания составного тяжелого горизонтального вращающегося вала

Drilling of wells, especially inclined and horizontal ones, is accompanied by the intense interaction of drilling tools with the borehole walls. Inborehole impacts negatively affect the drill pipe connections, electrical connections, strength characteristics of downhole motor structural elements, etc. The impact interaction of a drilling tool with a well is experimentally studied using a test bench, where the drilling tool sample is fixed in the middle of a heavy composite shaft arranged in cylindrical roller bearings. The rotating shaft is involved in the impact interaction with a cylindrical baffle due to bending vibrations. In this paper, a beam model of the described shaft is used to study the effect of the rotation speed, gravity forces, damping, and unbalance on the shaft motion. The research is carried out numerically using the ANSYS engineering software package. It is shown that the gravity forces shift the line of centers of gravity in shaft sections, relative to which it rotates. Damping, which is proportional to the speed, provides the shaft centering. The imbalance of the shaft causes bending vibrations. The possible modes of the shaft motion and the conditions for unstable motion are revealed. The mode of the shaft motion within a cylindrical baffle that ensures a steady periodic impact interaction is determined. This interaction induces elastic waves of the acceleration, transverse force and moments in the shaft.

Contact forces between roller and cage pocket in cylindrical roller bearings (Consideration based on dynamic behavior between roller and cage)

Contact forces between roller and cage pocket in cylindrical roller bearings (Consideration based on dynamic behavior between roller and cage)

Distribution Characteristics of Stress and Displacement of Rings of Cylindrical Roller Bearing Considering Thermal Effect

Distribution Characteristics of Stress and Displacement of Rings of Cylindrical Roller Bearing Considering Thermal Effect

Investigation of Dynamic Loads in Wind Turbine Drive Trains Due to Grid and Power Converter Faults

Electrical faults can lead to transient and dynamic excitations of the electromagnetic generator torque in wind turbines. The fast changes in the generator torque lead to load oscillations and rapid changes in the speed of rotation. The combination of dynamic load reversals and changing rotational speeds can be detrimental to gearbox components. This paper shows, via simulation, that the smearing risk increases due to the electrical faults for cylindrical roller bearings on the high speed shaft of a wind turbine research nacelle. A grid fault was examined for the research nacelle with a doubly fed induction generator concept. Furthermore, a converter fault was analyzed for the full size converter concept. Both wind turbine grid connection concepts used the same mechanical drive train. Thus, the mechanical component loading was comparable. During the grid fault, the risk of smearing increased momentarily by a maximum of around 1.8 times. During the converter fault, the risk of smearing increased by around 4.9 times. Subsequently, electrical faults increased the risk of damage to the wind turbine gearbox bearings, especially on the high speed stage.

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.

A simulation investigation of lubricating characteristics for a cylindrical roller bearing of a high-power gearbox

A fluid-structure coupling numerical model of an oil-jet lubricated cylindrical roller bearing (CRB) in a high-power gearbox is developed, in which the volume of fluid (VOF) method and slip mesh model are used. The heat sources of bearing are defined as the transient thermal boundary. The differences of temperatures between the rigid and flexible bearings are compared. The simulation results are validated by the presented experimental results. It indicates that the oil flow rate, speed, waviness amplitude and order, oil viscosity and nozzle number will significantly influence the bearing’s lubricating characteristics. The flexible bearing model with the transient thermal boundary is more accurate than those of other two models. To suppression the increment of bearing temperature, the waviness should be reduced.

Finite Element Analysis of the Thermo-mechanical Behaviour of Defect-Free Cylindrical Roller Bearing in Operation

Finite Element Analysis of the Thermo-mechanical Behaviour of Defect-Free Cylindrical Roller Bearing in Operation

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.

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.

Lubrication and loading characteristics of cylindrical roller bearings with misalignment and roller modifications

A new model for cylindrical roller bearings, capable of deterministically handling lubrication and misalignment situations, is developed by coupling a quasi-static model and a finite line-contact EHL solver. Numerical results of internal load, pressure, and film thickness between rollers and raceways as well as bearing stiffness are obtained with different configurations of diametrical clearances, speeds, lubricant viscosity, misalignment angles, and the roller-profile modifications. It is revealed that if the roller bearings operate under zero or negative clearances, the loaded zone expands and additional loads can be produced by lubrication due to geometric constraints to the rollers, especially under light load and high speed conditions. The logarithmic profile of the rollers tolerates the misalignment better than the dub-off or crown profile.

Power Loss Estimation and Thermal Analysis of an Aero-Engine Cylindrical Roller Bearing

High-speed rolling element bearings for aircraft engines are custom-made components and operate under high temperature conditions owing to the elevated rotational speeds and loads. Therefore, assessing the various heat generation sources and mechanisms is worth investigating to accurately quantify the overall power loss within the bearing. In this context, a numerical parametric study was performed to determine and locate various power losses inside an aero-engine cylindrical roller bearing. Then, a thermal network model based on Ohm’s law was developed to estimate the operating temperatures of the bearing elements. A series of experiments was carried out on a high-speed rolling element bearing test rig to validate the numerical predictions, such as bearing component temperatures and overall power loss at specific operating conditions. The numerical predictions based on a hybrid approach showed good agreement with the experimental data.

Abnormal Wear Mechanism and Improvement of High-Speed Cylindrical Roller Bearing

This paper presents the dynamic differential equations of cylindrical roller bearing, considering the dynamic unbalance mass of roller and the contact between the roller end face and the inner ring rib. The influence of bearing working condition and structural parameters on the P V value of roller end face and the slip speed of roller working surface were analysed. The theoretical analysis and experimental results both show that the large amount of roller’s dynamic unbalance mass due to the difference in chamfering size on both sides of the roller and the deviation of the bearing axial clearance are the main causes of abnormal wear on the roller working surface and end face.

A method for calculating radial time-varying stiffness of flexible cylindrical roller bearings with localized defects

In this paper, the flexibility of bearing parts and localized defects are considered, and a method for calculating the radial time-varying stiffness of flexible cylindrical roller bearings (CRBs) with localized defects is proposed. The proposed method uses the finite element (FE) method to calculate the global flexibility of bearing parts and adopts the analytical contact theory to calculate the localized contact flexibility of bearing parts. Furthermore, based on the displacement excitation assumption, localized defect models of the outer race, inner race, and roller are established. The proposed method is verified by comparing with the methods in the references and the finite element method. The effect of different angles of defect width on time-varying stiffness is discussed. The results show that as the angle of defect width increases, the width of the stiffness saltation also gradually increases. Besides, the calculation accuracy of the proposed method is higher than that of the classical analytical method, and the computational efficiency is greatly improved compared with the finite element method. This study can provide a theoretical basis for defect diagnosis of CRBs.