Tapered Roller Bearings Research Articles

Ultra-Durable Polysilicon Based Tribovoltaic Nanogenerators for Bearing In Situ Rotational Speed Sensing.

Tribovoltaic nanogenerator (TVNG) is an emerging energy device with the advantages of direct current and high power density. At present, many TVNGs are based on single-crystal materials, which are expensive and fragile during structural processing. Here, a polysilicon-based TVNG for bearing in situ rotational speed sensing is developed, which has the same level of performance and lower cost compared to monocrystalline silicon. The defects in polysilicon can provide additional carriers, but the grain boundaries can suppress the transport process of carriers, resulting in almost the same electrical output as single crystals. The oiled sliding mode TVNG has an impressive durability of up to 1 million cycles. The friction coefficient of rolling mode TVNG is as low as 0.14. Based on rolling mode polysilicon TVNG, the tapered roller bearing, thrust ball bearing, and deep groove ball bearing are manufactured by cutting and engraving processes. Moreover, their short-circuit current and open-circuit voltage are linear with speed, and the fitting coefficient is as high as 0.99, providing favorable conditions for in situ rotational speed sensing. This work presents a structure-function integrated bearing design methodology, demonstrating the considerable potential of in situ sensing for intelligent components in the industrial Internet of Things.

Investigating lubricant behavior in a partially flooded tapered roller bearing: Validation of a multiphase CFD solver for aerated oil sump via particle image velocimetry studies and high-speed camera acquisitions

In the recent years, the efficacy of utilizing sapphire outer rings as a viable tool for experimentally observing oil flows within rolling bearings has been demonstrated. However, in previous studies, such approach was applied under fully-flooded lubrication conditions exclusively. This paper presents the outcomes of observations and measurements conducted under oil-bath lubrication conditions of a vertical-axis Tapered Roller Bearing (TRB). The experimental work encompasses four operational speeds ranging from 1000 min−1 to 2500 min−1, and two oil levels, i.e. 10% and 100% of the bearing width. Pictures were captured using an High-Speed Camera (HSC) for a qualitative inspection. Particle Image Velocimetry (PIV) measurements were conducted for a quantitative assessment of the oil velocity fields. The findings reveal specific lubricant flows, highlight aeration, and show particular vorticity patterns that intensify with increasing speed. These experimentally obtained results align with Computational Fluid Dynamics (CFD) simulations conducted using a specially developed model in OpenFOAM®, leveraging a solver that accounts for aeration.

Research on Multi-Parameter Optimization of Conical Roller Line Processing Technology Based on Satisfaction Function

In the process of conical roller line processing, there will be problems such as low precision of processing parameters, long processing time, low utilization rate of machine tools, high rejection rate, and high processing cost, which will lead to low production efficiency. In order to solve this problem, it is necessary to iteratively optimize the size parameters, including inner diameter, ovality, and taper. By obtaining the optimal parameter combination, the size parameters in the production process are kept consistent, that is, the accuracy and performance of the workpiece during the processing are guaranteed so as to avoid the problem of quality difference, improve the production efficiency and reduce the processing cost. In view of the fact that there are often some constraints on the accuracy and efficiency in the machining process of tapered roller lines, how to optimize the parameters affecting the accuracy and the parameters affecting the efficiency to achieve balance between accuracy and efficiency in order to better meet the needs of customers for multi-objective optimization of the machining process has become the focus of research. Based on the existing research, this paper explores the multi-parameter optimization modeling and application in the machining process of tapered roller lines by constructing a satisfaction function, and then uses a genetic algorithm to iteratively search for the optimal solution by simulating natural selection and the genetic mechanism. Based on Python software v3.12, the production process of tapered roller bearings is simulated. The AHP analytic hierarchy process and CRITIC weight method are used to redistribute the parameter weights respectively. After eight iterations, it is concluded that the weight value assigned by the AHP analytic hierarchy process makes the satisfaction function value reach the best value of 0.99795 and tend to converge stably. The optimized parameter configuration significantly improves the machining accuracy and production efficiency of the tapered roller line. The optimal parameter combination is obtained: inner diameter: 9.9982 mm, ovality: 0.7 mm, taper: 0.5 degrees, production efficiency: 101.0.97 piece/h. In order to verify the optimization effect, the single value (X) and moving extreme difference (Rs) control charts in the measurement value control chart are used to analyze and verify the tolerance values of important parameters in the processing technology of the tapered roller line. The results show that the data points are all within the control limit, indicating that the processing process is in a statistical control state.

Influence of axial clearance on load distribution in double supported tapered roller bearings of wind turbine main shaft

The operational safety and stability of wind turbines are highly determined by the characteristics of main bearings, which are influenced by the axial clearance. In this paper, for the arrangement type of double-supported tapered roller bearings on the wind turbine main shaft, the actual clearance distribution assumption is established, and a new method of calculating the internal load distribution taking into account the axial clearance is proposed. Firstly, the mathematical relationship between the clearance of tapered roller bearings and ring displacement, contact deformation, and load interval is described. Secondly, the load components of main bearings are calculated by force balance equation and load-displacement condition. Finally, a mathematical model of main bearings including axial clearance is established, and it is numerically solved to obtain the internal load distribution of the bearings. The calculation results of a large megawatt wind turbine example show that: the axial load of both main bearings is negatively correlated with the sum of axial clearances; the number of loaded rolling elements is negatively correlated with the sum of axial clearances; and there exists an optimal value of the sum of axial clearances for main bearings to reach the optimal load carrying state.

Friction moment calculation method for tapered roller bearings under combined loads

Friction moment calculation method for tapered roller bearings under combined loads

Study on the vibration characteristics of double-row tapered roller bearings for high-speed rail axle box

PurposeThe purpose of this paper is to establish a dynamic model considering the actual operating conditions of the train and to study the dynamic performance and vibration characteristics of axle box bearings under different operating conditions.Design/methodology/approachIn this paper, based on the internal contact characteristics of double-row tapered roller bearings, a dynamic model considering the actual operating conditions of the train is established. The correctness of the model is verified by the vibration test of the bearing. Comparative analysis was conducted on the effects of axial force, radial force and rotational speed on the angular velocity of the cage, slip rate and vibration acceleration level of the inner ring.FindingsAs the force increases, the slip rate of the cages on both sides decreases, and the vibration acceleration level of the inner ring increases. With the increase of rotational speed, the cage slip rate of the axle box bearing increases and the vibration acceleration level of the inner ring increases.Originality/valueA dynamic model is established considering the actual operating conditions, and the dynamic performance and vibration characteristics of the axle box bearing under different operating conditions are analyzed by numerical method. The research content can provide reference for the parameter design of high-speed railway bearings.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0085/

Composite fault mechanism and vibration characteristics of high‐speed train axle‐box bearings

AbstractAxle‐box bearings are crucial components of high‐speed trains and operate in challenging conditions. As service mileage increases, these bearings are susceptible to various failures, posing a safety risk to high‐speed train operations. Thus, it is crucial to examine the deployment methods of axle‐box bearings. A dynamic model of axle‐box bearings for high‐speed trains with compound faults is constructed by setting up separate faults in two rows of double‐row tapered roller bearings based on a single‐fault model. The model's high accuracy in expressing compound faults is verified through corresponding experimental results. Then, the frequency domain diagram of system vibration response under varying rotational speed conditions is obtained, and the amplitude corresponding to the single frequency is extracted and analyzed to identify the optimal rotational speed band for composite fault diagnosis. Finally, the optimal speed band is analyzed under different faults, different load sizes, and different composite fault types. It can be concluded that the determination of the optimal speed band is solely influenced by the composite fault type and is independent of the fault and load sizes. Finally, it is concluded that the energy proportion of faults in different positions changes periodically with the change in speed, and this phenomenon is not affected by the fault sizes or load magnitude.

Stiffness increase in main spindles by using tapered roller bearings for aluminum cutting tests

Due to increasing demands regarding higher manufacturing accuracy and the machining of high-strength materials, the stiffness and load-carrying capacity of main spindles must be enhanced. One approach is to replace the conventionally used angular contact ball bearings, so called spindle bearings, with tapered roller bearings of the same size, which have a higher stiffness and load carrying capacity due to their larger rolling contact. In case the speed requirement is below a speed parameter n·dm=0.9×106\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$n\\cdot d_{m}=0.9\ imes 10^{6}$$\\end{document} mm/min, the poorer speed parameter of tapered roller bearings can be compensated by a sufficiently high lubrication quantity. However, the stiffness increase by using this bearing type in main spindles has not yet been quantified in field tests. Therefore, the aim of this paper is to demonstrate the stiffness advantage of a spindle with an elastically arranged tapered roller bearing compared to a conventional spindle with angular contact ball bearings by machining tests. First, the radial load displacement characteristic of the newly developed tapered roller bearing spindle is tested in advance on an isolated test rig. In machine cutting tests, full slots are milled in an aluminum block. During the tests, the axial and radial displacements of the spindle shaft relative to the housing are measured and evaluated in radial and axial direction. These tests are repeated and compared with the conventional spindle. By varying the process parameters such as cutting depth, feed rate or rotational speed, the increased stiffness of the tapered roller bearing spindle compared to the conventional spindle is illustrated based on the measured displacements. Moreover, frequency response measurements at different speeds underpin the improved damping of the tapered roller bearing spindle. Assuming that the speed requirements are not too high and the tapered roller bearing is sufficiently lubricated, the use of this type of bearing can significantly increase the stiffness and thus the manufacturing precision in the long term for main spindles.

Detection method for contact stress distribution of tapered roller bearings

The axle box of high-speed train adopts double row tapered roller bearings as transmission parts, and the reliability of bearings directly affects the safety of train operation. Tapered roller bearings can withstand axial and radial loads, their service life being closely related to the distribution of contact stress. The test object is the axle box bearing of high-speed train. According to bearing’s structural characteristics, based on the digital speckle correlation method (DSCM) and machine vision, the contact stress distribution detection devices for rollers and complete sets of bearings are developed respectively and an effective detection method is proposed. The contact stress data of the bearing which has reached the service life and the new bearing under the condition of no lubrication and grease lubrication are collected and normalized. Through the geometric relationship, based on the measured data of the selected detection points, the normal and tangential contact stress distribution of the roller and raceway under different contact conditions is obtained by data fitting. The test can be used as an evaluation basis for the effectiveness of bearing modification and provide reference for bearing design.

Vibration characteristics of defective axle box bearings in high-speed trains under track irregularity excitation

Track irregularity is a type of excitation source for the wheel-rail system, and it is also the major cause of vibration and wheel-rail forces on the axle box bearings of vehicles, and it is commonly found on in-service lines. Therefore, this paper mainly focuses on the dynamic characteristics of high-speed train axle box bearings under track irregularity. Firstly, a nonlinear system containing a faulty double-row tapered roller bearings is established, the obtained equations of motion are solved numerically using the Runge–Kutta and comparing it with the varying compliance vibration frequency and fault characteristic frequency obtained by formula, the comparison results verify the effectiveness of the model. Then, the track irregularity is coupled to the above bearing system, the model is also verified by using the rolling and vibrating test rig of single wheelset. Secondly, the eigenvalue of covariance matrix is introduced as an index to analyze the influence trend of different fault sizes, loads, and inner rotational speeds on the axial trajectory. Finally, the influence trend of track irregularity on the stability of vertical acceleration is analyzed by simulating different operating conditions.

Designing Large Segmented Flexible Conical Plain Bearings as Wind Turbine Main Bearings

Main bearings are failure-prone components in wind turbines, significantly increasing the LCOE of wind energy. Therefore, segmented plain bearings are being discussed as replacement for the currently used rolling bearings. Segmented plain bearings allow an up-tower replacement of faulty segments without the need to dismantle the WT drivetrain, as is required for rolling bearing replacements. One such bearing is the segmented, flexible, conical “FlexPad” plain bearing as alternative to existing double row tapered roller bearings. Designing the FlexPad bearing manually is very complex and thus time-consuming. Hence, during the research project a new holistic design method for large and highly loaded, conical plain bearings was developed. To prove the suitability of the method, two bearing prototypes were built and tested. The prototype, designed with the new method, outperformed the first, manually designed bearing, in terms of the design objectives. Most importantly, the friction losses were reduced by 32.1%. The project results show that the new method is able to efficiently design safely operating FlexPad bearing variants for wind turbines.

Assessment of the Correlation between the Monitored Operating Parameters and Bearing Life in the Milling Head of a CNC Computer Numerical Control Machining Center

The present paper describes a study conducted at the request of the operator of machining center equipment. The operator observed undesirable indicators in terms of increased backlash and vibration of the milling head and poor quality of the machined surfaces. Vibration measurements and vibrodiagnostics were carried out before disassembling the milling head in the idle state. The bearings, lubricant, and friction regime were analyzed in the next step. The vibrodiagnostic methods used included VEL, ACC, EN2, EN3, and EN4, with recommended limits conforming to STN ISO 10816-3. The vibration values obtained indicated a problem with the bearings, exceeding the limit values. After disassembly of the bearings, abrasive wear, corrosion, and improper lubricant conditions were detected. Lubricant analysis showed the presence of abrasive and corrosive particles, indicating an unsatisfactory friction regime. Determining the optimum lubricant temperature and the effect on friction torque constituted other aspects of the study. Inspection of the bearing microgeometry confirmed unsatisfactory roundness. Furthermore, the assembly of tapered roller bearings with axial preload was analyzed with a focus on bearing stiffness, accuracy, and life. The results showed that preload improves shaft guidance accuracy and load distribution, promoting reliable operation and extending bearing life.

Surface Defects Vibration Measurements of Automotive Tapered Roller Bearings

The paper investigates vibration testing methodologies for automotive tapered roller bearings. The European Union regulations have indirectly led to improvements in the NVH performance of the bearings that affect both the industrial and automotive markets. The goal of this study was to examine the influence of localized small defects on the vibrations’ magnitudes within tapered roller bearings. A Rockwell indenter was used to create three different surface defects. These three levels, representing different indentation pressures, mimic defects that could occur during manufacturing or bearing installation. Indents were placed on inner raceways, the outer raceways, and the roller bodies. After the assembly of the components, different vibration testing methodologies were applied to quantify those types of defects. This paper presents a new envelope analysis approach to monitoring for defects. The paper presents the current Fast Fourier Transform (FFT) testing approach, whereby the machine sensitivity is representative of a typical quality control bearing thresholds. This paper also presents a new, more robust method and analyzed for its suitability in the detection of localized defects.

Experimental investigation of the static and dynamic damping behaviour of antifriction bearings

ABSTRACT This paper experimentally investigates the vibration-damping behaviour of four different antifriction bearings. Both static and dynamic analyses have been employed to study the damping behaviour. Experiments are conducted on a custom-made rotor bearing test rig, and the results are analysed with the OROS NV-Gate data collection system at DE (Drive end) and NDE (Non-drive end). Free vibration analysis is used to determine natural frequencies. The half-power bandwidth and logarithmic decrement methods are used to get the damping ratios. Furthermore, force vibration tests are carried out on different bearings with varying operating characteristics to support the static analysis results. The results demonstrate that the damping capacity of tapered roller bearings is superior, followed by cylindrical, spherical and self-aligned bearings. The contact between rolling elements and raceways plays an essential role in the damping capability of such bearings. The result of current research has prospective applications in the design of high-performance rotor bearing systems.

Thermal elastohydrodynamic lubrication analysis of the oil film temperature in tapered roller bearings

Tapered roller bearings often experience thermal deformation and stress concentration due to high temperature during prolonged operation. However, the traditional model for calculating bearing heat does not consider the thermal elastohydrodynamic behavior of the lubricant. To address this issue, this paper proposes a finite line contact model based on thermal elastohydrodynamic lubrication analysis for calculating the temperature distribution of the lubricant within tapered roller bearings. The temperature of the lubricant is solved using the column-by-column technique. The results show that the temperature distributions along the thickness of the oil film are symmetrical, with the highest temperature occurring at the middle layer. Furthermore, the temperature at the middle layer increases with both the bearing speed and the concentrated load. These findings provide a theoretical framework for calculating the temperature distribution of lubricated bearings, offering valuable insights for practical applications.

Numerical Investigation of Oil–Air Flow Inside Tapered Roller Bearings with Oil Bath Lubrication

Oil–air flow within an oil bath lubrication tapered roller bearing is essential for the lubrication and cooling of the bearing. In this paper, we develop a simulation model to investigate the flow field of tapered roller bearings with oil bath lubrication. The multiple reference frame (MRF) approach is used to describe the physical motion of the bearing, and the volume of fluid (VOF) two–phase flow model is used to track the oil–air interface in the flow field. The effects of mesh scale, geometric gap, and oil reservoir size on calculation time and convergence accuracy are examined in detail, and the effects of inner ring rotational speed and lubricant viscosity on frictional torque are systematically studied. The results of the numerical simulation indicate that as the gap distance between the raceway and the rolling elements decreases, the frictional torque is mainly generated by churning losses at the inner raceway and the rolling elements. The frictional torque increases with increasing inner ring speed and lubricating oil viscosity, with the rolling element contributing the largest portion at approximately 50% of the total. We demonstrate the effectiveness of a method to reduce frictional torque by optimizing the internal structure of the bearing to control oil flow. By optimizing the cage structure and reducing the roller half-cone angle, frictional torque can be reduced by 29.1% and 26.2%, respectively.

Measurement of the roller tilt angle in a double-row tapered roller bearing with strain gauges

Roller tilting can cause severe roller-edge loadings, leading to serious local heat generation or early failure of the rolling element bearing. Therefore, it is significant to obtain the roller tilt angle in real service for evaluating the bearing performance. A measurement method was proposed to determine the roller tilt angle by detecting the variation of the strain amplitude difference between two axial positions of the bearing outer surface with a notched housing. An experimental system was developed to investigate the roller tilt angles in a double-row tapered roller bearing and demonstrate the effectiveness of the proposed measurement method by conducting a comparison with the finite element method (FEM) simulation results. The experimental roller tilt angles agree well with the FEM results. Compared with other measurement methods, the proposed method offers a potential approach to achieve the in-situ and non-destructive measurement of the roller tilt angles for long-term monitoring.

Computer-aided analysis of tapered roller bearings for rail transport system

Computer-aided analysis of tapered roller bearings for rail transport system

Study on Grinding-Affected Layer of Outer-Ring Inner Raceway of Tapered Roller Bearing.

In the grinding of bearing raceways, the coupling effect between grinding force and heat in the contact area between the grinding wheel and the workpiece causes changes in the material structure and mechanical properties of the raceway surface layer, which can lead to the formation of a grinding-affected layer. The grinding-affected layer has a significant impact on the service performance and fatigue life of bearings. In order to improve the ground surface quality of the outer-ring inner raceway of tapered roller bearings and optimize the processing parameters, this paper presents a study on the grinding-affected layer. A finite element simulation model for grinding the outer-ring inner raceway of the tapered roller bearing was established. The grinding temperature field was simulated to predict the affected-layer thickness during raceway grinding. The correctness of the model was verified through grinding experiments using the current industrial process parameters of bearing raceway grinding. The research results indicate that the highest grinding temperature of the outer-ring inner raceway of the tapered roller bearing is located near the center of the grinding arc area on the thin end edge. As the workpiece speed and grinding depth decrease, the highest grinding temperature decreases, and the dark layer thickness of the grinding-affected layer decreases or even does not occur. The research results can provide theoretical guidance and experimental reference for grinding the raceway of tapered roller bearings.

Load-Independent Power Losses of Fully Flooded Lubricated Tapered Roller Bearings: Numerical and Experimental Investigation of the Effect of Operating Temperature and Housing Wall Distances

To improve roller bearing efficiency, it is essential to identify the sources of power losses and quantify them in the design stage, considering different influencing factors. For oil-lubricated bearings, load-independent power losses ( ) can be the dominant source of dissipation, especially for high-speed and abundant lubrication. In the present work, of a 32208 tapered roller bearing were measured experimentally under various operating conditions; that is, different rotational speeds, temperatures, and geometries of the oil reservoir. A numerical tool, based on computational fluid dynamics, to estimate and provide useful insights to investigate their causes has been developed in the OpenFOAM® environment. Numerical and experimental results show excellent agreement in most of the operating conditions investigated. Oil flows, contributions of different bearing components, and computational effort are discussed in the article.