Taper Roller Research Articles

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.

EFFECT OF LOADING ON DEGRADATION OF TAPER ROLLER BEARING USING VIBRATION SIGNAL

Studies reveal that the most prominent cause of bearing failure is a crack on any of its mating surfaces. When the crack is initiated, the bearing can still be used for some duration, but this is majorly depending upon the loading conditions. This work primarily focuses on the effects of different levels of static loading on the crack propagation after crack initiation. To analyze the effect of static loading, an axial groove defect was seeded on the outer race of a taper roller bearing randomly and bearing run continuously under five different static loading conditions. Initially, the bearing was made to run under loading conditions to initiate the crack naturally but the crack was not initiated even after 800 h of running. Therefore, crack was initiated artificially for the purpose of studying crack propagation. It was observed from the experimentation that in the case of maximum static load of 20 kg, the crack propagates rapidly in terms of area after 109 h of continuous running, whereas in the case of no load, it started propagating quickly after 267.5 h of running. Statistical analysis was also carried out for the recorded signals at different intervals of times, and it was observed that the Shannon entropy value was showing a sudden rise with the edge breakage (visually verified) while the crack was propagating. However, in the statistical analysis, none of the parameters showed a correlation with crack propagation. To develop the correlation of crack propagation, Shannon entropy of high, medium and low frequency bands of continuous wavelet-based (CWT) was carried out using different wavelets. Shannon entropy for high frequency band of CWT using Daubechies 10 as mother wavelet has responded well to the crack propagation as the value showed a sudden rise and an overall increase for edge breakage and crack propagation, respectively. A high frequency band of CWT using Daubechies 10 was found suitable for detecting edge breakage and crack growth at the same time because of its capability to respond to transient characteristics for a large duration of time.

Identification of localized defects and fault size estimation of taper roller bearing (NBC_30205) with signal processing using the Shannon entropy method in MATLAB for automobile industries applications

Rotating machine is a common class of machinery in most of the industry and the main root cause of machinery failure is a faulty bearing. Bearings are most widely used in various types of machine elements ranging from small to heavy machinery and the common cause of machinery failure is a fault in bearings. Bearing faults can be external or internal which mainly depends on different operating conditions and these faults may cause severe damage to rotating components in machinery. Signal processing methods have traditionally been used to diagnose faults in tapered roller element bearings. A wavelet transform is the most common and effective tool for understanding and analyzing the vibration signal of bearings as it is responded quickly and observed sudden changes along with the transient impulses in the signal caused by faults in the different parts of bearing elements. In this article, localized fault's position and size on the outer ring of tapered roller bearing were investigated. Three different real values wavelets (DB2, Meyer, and Morlet) are analyzed as per Simple Sensitivity index criteria. Finally, experiments are carried out with four sets of bearing having fault on outer racing of bearing, and for the estimation of fault size, the setup was misaligned at ranging (0.00mm–1.50 mm) with a uniform deviation of 0.50 mm for each experiment. Shannon entropy was calculated for the identification of localized size of the faults with wavelets nomenclature, the result of DB2, Morlet, and Meyer wavelets at high-frequency zone are presented.The scanning electron microscope (SEM) has been taken for the estimation of size of the fault. The proposed method has been successfully implemented for measuring defect width and size. Also, it has been observed that with increased magnification level from 0.00 mm to 0.50 mm, the crack width of the faulty bearing was increased by 0.813 mm, and whenever on further increase in magnification level of 0.50, 1.00 mm and 1.50 mm the crack width of the faulty bearing was increased by 2.568 mm and 3.856 respectively.

Theoretical and Experimental Investigation on Thermal Characteristics of Railway Double-Row Tapered Roller Bearing

The research on the thermal characteristics of railway double-row tapered roller bearing is of great significance for its structural design and operation monitoring. We established the quasi-static mechanical model of the bearing according to the test conditions, and we obtained the load distribution and kinematic parameters of the bearing. We studied the temperature distribution of railway double-row tapered roller bearing under test conditions through finite element analysis, which was consistent with the test results. We built a bearing testbed to study the effects of different rotating speeds on the temperature distribution of the bearing inner ring, outer ring, and roller. The results show that the speed dramatically affects the bearing inner ring. With the rate increase, the temperature difference between the inner and outer rings decreases gradually, and the temperature at the large end of the roller is the highest.

No-Load Power Loss of a Rear Axle Gear Transmission: Measurement and Validation

Abstract This work studies the power loss in a real axle box gear transmission under no-load operating conditions. The influence of the rotational speed and of the lubricant viscosity was considered. An experimental strategy was adopted in order to measure the overall power loss of the axle box, as well as to isolate the power loss contribution of the major components: crown wheel, pinion, seals, and the tandem taper roller bearings supporting the pinion shaft and the crown assembly. Although it was not possible to directly measure the power loss generated by each component, the results allowed to identify the major contributions to the rear axle inefficiency. In particular, those from the crown wheel churning, from the lubricant squeezing due to the pocketing between the pinion and crown gear teeth, and from the friction in the preloaded tapered roller bearings of the pinion shaft and of the crown assembly. In average, the tapered roller bearings supporting the pinion shaft are responsible for 74% of the overall power loss of the axle box. A numerical model was developed to predict the power loss of the axle box and of its components, which was correlated with the experimental measurements with high accuracy (R2 = 0.9990). The combination of the experimental measurements with the model predictions allowed a full understanding of the axle box power loss behavior under no-load operating conditions. This analysis can be used for the design of an axle box with improved efficiency.

Optimization of Mechanical Efficiency Models for 2D Piston Pumps with a Stacked Taper Roller Set

Since the clearance between the guide rail and the roller reduces the efficiency of the 2D pump, this paper proposes a novel 2D piston pump with stacked taper roller sets to eliminate the effect of the clearance. The structure of the 2D pump is introduced, and the mathematical model of the torque and the mechanical efficiency of the bilateral force on the guide rail are established and analyzed. The model takes into account the change in the oil viscosity, the spatial angle and the oil churning loss. A test rig was built to test the mechanical efficiency under different operating conditions. The unilateral and bilateral force models of the guide rail were compared, which proved that the bilateral force model of the guide rail can predict the mechanical efficiency more accurately than the unilateral force model. In the case of high load pressure, there was a clearance between the test results and the model calculation results. It is speculated that the main reason for this is that the greater oil pressure causes the size of the contact area between the two taper rollers and between the taper roller and the guide rail to become larger. The resulting rolling friction coefficient becomes larger, which affects the mechanical efficiency.

Detecting Crack Propagation Rate in Taper Roller Bearing Using FEA Analysis and Signal Processing Techniques

Detecting Crack Propagation Rate in Taper Roller Bearing Using FEA Analysis and Signal Processing Techniques

Effects of Raceway Convexity on Friction Moment of Tapered Roller Bearings

The Effects of raceway convexities on friction moment of tapered roller bearings were studied in this paper. A new theoretical model of friction torque of tapered roller bearings was established considering the roughness and convexities of inner and outer ring raceways. Friction between roller and raceways were analyzed under the condition of elastohydrodynamic lubrication. Based on the theoretical model and experiments, the changes of friction torque with respected to raceway convexities of tapered roller bearings were obtained. The results show that the friction moment decreases with the increase of raceway convexities, while the increase of raceway convexity leads to the increase of contact stress. Therefore, the convexity values should be balanced between friction torque and contact stress. The convexity values should be balanced between friction torque and contact stress. The optimum values of the bearing being measured raceway convexities should be 5 ~ 6μm under the test conditions.

Bearing defect identification by swarm decomposition considering permutation entropy measure and opposition-based slime mould algorithm

An intelligent defect identification scheme has been proposed to identify the taper roller bearing defects through the extreme learning machine (ELM) model. The raw vibration signal from the bearing test rig is decomposed into different modes by Swarm decomposition (SWD) method to remove noise. The permutation entropy (PE) is taken as a measurement index to select the prominent mode. Features sensitive to defect conditions are extracted from prominent mode using a filter-based relief algorithm. The ranking of fault features is done on the score values. An opposition-based slime mould algorithm is investigated for finding the optimal parameters (weight connecting the input layer with output layer; and biases in hidden neurons) of ELM. Using optimized ELM parameters, the classification model is built. Test data evaluate the fitness of the built ELM model. Both the training and testing accuracy are 100%, with a computation time of 0.0023 s.

An Arrangement and Performance Analytics of Elements of Vibration Testing Machine for Taper Roller Bearing

The paper addresses the need for automation in production line. A detailed evaluation of various components required for converting a manual bearing vibration testing machine to an automatic one is carried out. Function and Description of each component is studied. The components include conveyor belts, laser Doppler vibro meter, pneumatic system, mechanical probe, timing and control sensors, speed control system, data analysis and storage unit. A method of selecting each component for automatic vibration testing machine is offered. Based on the structure of automated machine the initial set of alternate variants is defined and a formal model of automatic vibration testing machine is developed. Design of conveyor belt, linear drives, pneumatic system, isolation pad, PLC and HMI system is discussed below. Analysis of supporting structure of Vibration Testing Machine is done using ANSYS 18.1 and results are shown.

Misalignment effect on gearbox failure: An experimental study

Overhang-meshing gears, deflection of pinion/gear shaft, bearing wear, assembly error, poor adjustment of bearings and foundation are the reasons of misalignment in gear drives.In the present work, the misalignment effect on gearbox failure is investigated experimentally using vibration analysis. Misalignment between motor and gearbox is measured using laser alignment system (LAS). The effect of input shaft speed and load on the gearbox failure is also discussed.The misalignment effect primarily observes on the gearbox drive end taper roller bearing and distresses gear transmission. Physical and microscopic examinations of the dismantle gearbox confirm similar findings as observe from vibration spectrum. Severe damages in taper roller bearing (32206) and multiple pits on all the rollers and cone. The bearing cage is deformed badly due to overload and misalignment. The effect of bearing failure on gear’s damage is also investigated. Non-uniform contact patch is observed on the meshing gears in the plane of action. Misalignment results in scuffing failure on the pinion addendum and gear dedendum regions due to limited lubricant in the overstress region. At the end of the test, all the four seals appears safe, while the coupling spiders damage seriously.

Failure Investigation of Rear Axle Taper Roller Bearing by Using the Vibration Spectrum

Prevention of the occurrence of field failures of taper roller bearings under high-load and moderate-speed application is the prime challenge for bearing manufacturers. Failures result from numerous defects in bearing, such as localized or distributed defects. Various controls have been aligned in the manufacturing process to prevent outflow of defective bearings to end-application. However, still a part in million skips the controls in process and gets assembled in final application. In this literature, experiments are conducted to study the effect of grinding defect on cone track surface of taper roller bearing using the vibration spectrum, due to its peculiar unidentifiable nature in regular manufacturing process. Vibration analysis techniques are discussed in this case study. Statistical and spectrum analysis results are shared and concluded at the end of this case study.

Effects of Bearing Locations on the Characteristics of a Spindle System Supported by Tapered Roller Bearings

This paper presents the effects of bearing locations on the mechanical characteristics of a multi-stepped spindle system related to bearing fatigue life, natural frequency, and static stiffness. The multi-stepped spindle is supported by a pair of tapered roller bearings (TRBs) and subjected to radial loading. To solve the equilibrium equation of the spindle system which is inherently statically-indeterminate, this study adopts an integrated shaft-bearing model, where the spindle is modelled by the finite shaft elements and the supporting TRBs are modelled by the five degrees-of-freedom TRB model developed by the authors. An iterative computational method is used to estimate the spindle deflection coupled with bearing deflections, and afterwards the bearing stiffness and internal contact loads of rolling elements are computed. The bearing fatigue life based on the ISO standard and the first natural frequency of the spindle system are evaluated with the spindle-bearing model. The influences of bearing locations on the static stiffness and natural frequency of the spindle, and the fatigue life of TRBs are rigorously investigated. The numerical results show the noticeable effects of bearing locations on the spindle system characteristics. The presented results provide a comprehensive assessment to aid for design optimization of spindle-TRB system.

Trend of Technology for Automotive Needle Roller Bearings and Tapered Roller Bearings Contributing to Improvement of Fuel Efficiency

Trend of Technology for Automotive Needle Roller Bearings and Tapered Roller Bearings Contributing to Improvement of Fuel Efficiency

Signal Processing for Enhancing Impulsiveness Toward Estimating Location of Multiple Roller Defects in a Taper Roller Bearing

Abstract Rolling element defect identification is a difficult task. The reason being that defect on the rolling element has both rotational as well as revolutionary motion. To identify rolling element defect in a taper roller bearing, a novel signal processing scheme is proposed which results in a substantial increase in kurtosis and impulse factor of the vibration signal. The scheme constitutes a series of operations. In the beginning, the raw signal is decomposed by ensemble empirical mode decomposition (EEMD) and inverse filtering (INF). The above two stages of signal processing extract hidden impulses which are suppressed in the noise present in the experimental data. In the third stage of processing, continuous wavelet transform (CWT) using adaptive wavelet is applied to the preprocessed signal to produce a 2D map of the CWT scalogram. This transformation results in a higher coefficient in the region of impulse produced due to the defect. Finally, time marginal integration (TMI) of the CWT scalogram is carried out for defect localization. The defect frequency was evaluated with an accuracy of 97.81% and defect location was identified with an accuracy of 92%.

Prognostics Models for Railroad Tapered Roller Bearings with Spall Defects on Inner or Outer Rings

Rolling contact fatigue (RCF) is one of the major causes of failure in railroad bearings used in freight service. Subsurface inclusions resulting from impurities in the steel used to fabricate the bearings initiate subsurface fatigue cracks, which propagate upwards and cause spalling of the rolling surfaces. These spalls start small and propagate as continued operation induces additional crack formation and spalling. Studies have shown that the bearing temperature is not a good indicator of spall initiation. In many instances, the temperature of the bearing increases markedly only when the spall has spread across major portions of the raceway. In contrast, vibration signatures can be used to accurately detect spall initiation within a bearing and can track spall deterioration. No monitoring technique can indicate the growth rate of a spall or determine residual useful life. Hence, the main objective of this study is to develop reliable prognostic models for spall growth within railroad bearings that are based on actual service life testing rather than theoretical simulations. The data used to devise the models presented here were acquired from laboratory and field testing that started in 2010. Growth models are provided for spalls initiating on the bearing inner (cone) and outer (cup) rings. Coupling these prognostic models with a previously developed vibration-based bearing condition monitoring algorithm will provide the rail industry with an efficient tool that can be used to plan proactive maintenance schedules that will mitigate unnecessary and costly train stoppages and delays and will prevent catastrophic derailments.

Air – Oil Lubrication for Work Roll Bearing to Optimise Mills Breakdown

Bearing failure is one of the major concern in Indian Steel Industries as the failure leads to breakdown of the machine and thereby causes huge production loss. Bearing performance depends on design, selection of bearing type, lubricant and the type of maintenance practice chosen for it. In Steel industries there is not much scope to play for enhancing the bearing performance except good maintenance practice and manoeuvre with the lubricant and lubrication system. It is desired for any lubrication or lubrication system to optimise lubricant consumption without compromising the performance /life of the bearing. There are many systems which can provide lubricant with desired viscosity to the bearings. Grease is sticky, so it gets contaminated quickly. Consumption of grease is a bit higher and it does not help to increase the mill speed. The oil mist lubrication is better than grease lubrication system. But it has the problem of atomise oil droplet mix with air which creates foggy and unhealthy atmosphere in the shop/plant. The Air-Oil lubrication system sends metered quantity of lube oil in the form of oil streak through a distributor, carried by dry compressed air into bearing to lubricate it. The carrier air prevents entry of foreign particle in the lubricant and avoids lube oil contamination. It also helps in reaching the lubricant into the bearing clearance to maintain an oil film and it avoids the direct contact with rolling elements and races. Here in this work an attempt is made to enhance the performance of taper roller bearing of Cold Rolling Mill by implementing Air- Oil Lubrication system.

Reconstruction of angular speed variations in the angular domain to diagnose and quantify taper roller bearing outer race fault

Abstract Monitoring of rotating machines is usually performed on vibration signals and associated signal processing tools focus on extracting weak cyclic information induced by faults on mechanical components like bearings. Their sensitivity to operating conditions in speed and torque are of huge interest in recent research activities. An alternative signal consists in measuring Instantaneous Angular Speed (IAS) of the machine which has been empirically demonstrated as a good vector of information. Angularly sampled by nature, this signal investigates other transfer paths from fault to transducer and introduces new challenges in understanding the relationships between operating conditions and effects of faults on the rotating speed of the machine. The main contribution of this paper lies on the introduction of basic signal processing techniques in order to analyze the shape of rotating speed fluctuations introduced by bearing faults. Modifications due to operating conditions and size of the defect are clearly separated in our suggested analysis on IAS. Another point of interest relies on the fact that this tool can be used in stationary or non-stationary operating conditions. All the analysis are given on experimental data performed on a specific test bench with different artificial bearing faults in various operating conditions.

Experimental and numerical investigation of defect-size estimation in taper roller bearing

In this article, the estimation of different defect sizes present on the outer race of taper roller bearing confirms the effectiveness of the applied method for different vibration signals. Experiments and numerical model conducted for three primary conditions of bearing setting, which are positive, negative, and zero clearance. The outer race is installed in five different positions so that the defect located at 0°, 45°, 90°, 135°, and 180°. The output of the numerical model finds close correlation with the vibration signal pattern–obtained experiments. From the results, it is clear that defect-size estimation is more precise when the defect is introduced in the unloading area, and the contact time depends directly on the size of the defect, through which it is easy to calculate its value of the defect.

Finite Element Analysis of Cartridge Tapered Roller Bearing of Freight Wagon

Freight trains run under high service loads during consignment loading and operation so tapered roller bearings are ideally suited to wheel bearing applications. The tapered roller bearings used in the railway industry are of a standard design fixed by the American Association of Railroads regulations. Nowadays rail industry improves the train operating speeds, which means that failure of a bearing will result into a derailment, affecting human lives, network disruption, and damage to the railroad, unplanned maintenance costs, and generating fear in general public about rail transport. So the rail industry has focused on the improvement in maintenance work and improvement in component design. This paper discusses the results of finite element analysis and model analysis of Cartridge Tapered Roller bearing (CTRB). Solid modelling of CTRB has been done using solid works. The CTRB is then discretized using ANSYS software and 3D hexahedral solid elements are used to mesh the components. The effect of vibration modes on the dynamic behaviour and stability of wagon is described. Frequencies up to a range of 100 Hz are considered for mode shapes.