Tapered Roller Bearings Research Articles

Analysis of Dynamic Characteristics of Grease‐Lubricated Tapered Roller Bearings

Tapered roller bearings (TRBs) are applied extensively in the field of high‐speed trains, machine tools, automobiles, etc. The motion prediction of main components of TRBs under grease lubrication will be beneficial to the design of bearings and the selection of lubricating grease. In this study, considering the dynamic contact relationship among the cage, rollers, and raceways, a multibody contact dynamic model of the TRB was established based on the geometric interaction models and grease lubrication theories. The impacts of load, grease rheological properties, and temperature on the roller tilt and skew and the bearing slip were simulated by using the fourth‐order Runge–Kutta method. The results show that the roller tilt angle in the unloaded zone is obviously larger than that in the loaded zone, while the roller skew angle in the unloaded zone is smaller than that in the loaded zone. As the speed increases, the roller tilt and skew and the bearing slip become more serious. Bearing preload can effectively reduce the bearing slip but will make the roller tilt and skew angle increase. The roller skew angle and the bearing slip decrease with the increase of the grease plastic viscosity. The roller tilt angle increases with the increase of the plastic viscosity. The yield stress of the grease has little effect on motions of the roller and cage. The influence of temperature on the roller and cage motions varies with the type of grease used.

Study On The Influence Of Shaft Material On Vibration In Rotating Machinery

Vibrations are an inherent phenomenon in rotating machineries. They are present in all types of machines and mechanical components. They are unwanted because they affect the optimal performance of these components and hence, it needs to be eliminated. Amongst the different parameters that affect vibration, selection of appropriate material is the most critical parameter. In this research paper, the effect due to the use of different types of shaft materials on vibration in rotating machinery is studied and the magnitude of vibration produced due to the use of different type of shaft material under the same condition of loads and rotational speeds was investigated. Shaft materials considered in this paper were stainless steel and mild steel and these materials were tested for Ball Bearing, Thrust Bearing and Tapered Roller Bearing. From experimental result, it was observed that mild steel gives the high amplitude of vibration for all the three bearings. Hence, it is preferable to use Stainless Steel than Mild Steel in rotational machineries due to its physical properties and lower vibration amplitude in varied conditions.

Investigation for Vibrations of Tapered Roller Bearing Considering the Surface Waviness on the Rib of the Inner Race

Investigation for Vibrations of Tapered Roller Bearing Considering the Surface Waviness on the Rib of the Inner Race

LOW SPEED ROLLING BEARING DIAGNOSTICS USING ACOUSTIC EMISSION AND HIGHER ORDER STATISTICS TECHNIQUE

Diagnostics in low speed rolling element bearings is difficult. Not only are normal frequency domain diagnostics methods not appropriate for this application, but the bearing response signals are usually immersed in background noise which make it difficult to detect these faults. Higher order statistics (HOS) techniques have been available for decades but have not been widely applied to machine condition monitoring with the exceptions of skewness and kurtosis. There is however reason to believe that these HOS techniques could play an important role in acoustic emission (AE) based condition monitoring of rolling element bearings at low speeds provided appropriate care is taken. To explore this hypothesis, AE signals at low bearing rotational speeds of 70, 80, 90 and 100 rpm respectively were used in this work for the monitoring of tapered roller bearings. In addition to the well-established statistical parameters such as mean, standard deviation, skewness and kurtosis, higher moments such as hyper flatness are considered in this study. A novel diagnostic method is proposed for fault extraction based on hyperflatness, combined with Kullback-Leibler divergence, and an indicator formula derived with the use of Lempel-Ziv Complexity is given. The Kullback-Leibler divergence is used together with the skewness and hyperflatness to obtain the Kullback-Leibler information Wave (KLW)with which the analysis is performed, and better results obtained as compared to conventional frequency domain analysis.

Study on Change of Axial Load of Tapered Roller Bearing at Fixed Position Preload

Study on Change of Axial Load of Tapered Roller Bearing at Fixed Position Preload

Incipient Fault Diagnosis for Large Reducer Taper Roller Bearings Based on Non-convex Penalty Regularization Sparse Low-rank Matrix Approach

Incipient Fault Diagnosis for Large Reducer Taper Roller Bearings Based on Non-convex Penalty Regularization Sparse Low-rank Matrix Approach

Effect of Herringbone Type Micro Patterning on the Large Roller End Face of Tapered Roller Bearing to Torque

Effect of Herringbone Type Micro Patterning on the Large Roller End Face of Tapered Roller Bearing to Torque

Statistical investigation into the effects of distributed roller diameter error on the fatigue life of tapered roller bearings

This study examined the effect of distributed roller diameter error on the fatigue life of a Tapered roller bearing (TRB). To this end, a comprehensive analysis procedure to perform a statistical analysis of the fatigue life with respect to dimensional error was presented. The roller diameter error was assumed as normally distributed, with a designated mean value and a varying standard deviation. Simulations were conducted to investigate the effects of roller diameter deviation on the fatigue life of the TRB. The numerical results showed that the normally distributed roller diameter error did not necessarily result in a normally distributed bearing fatigue life. The adequate distribution function for the bearing fatigue life with respect to the roller diameter error was explored and found to be dependent on the amount of standard deviation of roller diameter error. The Weibull distribution is appropriate for a small standard deviation, while the gamma distribution and normal distributions are appropriate for large and in-between standard deviations, respectively.

Dynamic analysis of a tapered roller bearing

PurposeThis study aims to analyze the roller dynamic characteristics and cage whirling of tapered roller bearing considering roller tilt and skew which provide a theoretical basis for the design and application of tapered roller bearing.Design/methodology/approachBased on rolling bearing dynamic analysis, the dynamic differential equations of tapered roller bearing are established. Fine integral method and predict correct Adams–Bashforth–Moulton multi-step method are used to solve the dynamic differential equations of tapered roller bearings.FindingsFriction at the flange contact between roller and large flange is the chief factor of roller skew. In comparison to cone speed, axial loads have more visible effect on roller skew, and proper speed or axial load is beneficial to sustain cage motion and decrease cage instability. Under the combined effort of axial load and radial load, the distribution of roller skew is correlated to the roller-flange contact load. In addition, roller skew angle in loaded zone is larger than that in unloaded zone; hence, it is helpful for cage stability if an extent radial load is applied. The pocket clearance of cage has very small influence on roller skew; therefore, a reasonable pocket clearance is suggested to assure minimum instability of cage. Friction coefficient of flange contact has a large effect on roller skew, and cage whirl is found to demonstrate a circular orbit with increasing friction coefficient.Originality/valueThe dynamic differential equations of tapered roller bearing considering roller large end/inner ring back face rib contact under various lubrication states were established. The impact of flange friction working conditions and cage pocket clearance on cage instability and roller skew were focused on. It is the first time that the ratio of the standard deviation of the cage-center translational speed to its mean value is used to access the instability of cage in tapered roller bearing.

Support Vector Machine with Wavelet Decomposition Method for Fault Diagnosis of Tapered Roller Bearings by Modelling Manufacturing Defects

Tapered roller element bearings are generally applied in machines and transmission gearboxes. In manufacturing outer ring, inner ring and the rollers usually suffer damages. It is a challenging task to reveal and classify the defects. This paper presents an efficient method for fault classification by support vector machines. The faults on the bearing parts created by laser beam machine have similar shape and surface topography as the grinding faults from the manufacturing process. Vibration signature is collected by sensitive transducer and high resolution data acquisition unit. A test-rig is constructed to model the circumstances of the operation of the built-in tapered roller bearings. Moreover, test-rig is planned with the aim to mitigate the harmful vibration components from the environment that influence the precision of the vibration measurement. Feature extraction is executed by wavelet decomposition. Decomposition level is determined by FFT considering the structural frequencies of the bearing elements. The proper wavelet is selected by the Energy-to-Shannon Entropy criteria from Daubechies and Symlet wavelet families. The fault classification is done by R Cran software using support vector machine classifiers. Time domain parameters of the vibration signature such as kurtosis, skewness, crest factor and range are provided to the classifier. Classification rates are high enough to ensure the efficiency of the method in all cases in the study.

The Evaluation of Efficiency of the Use of Machine Working Time in the Industrial Company – Case Study

Abstract In the paper the evaluation of efficiency of the use of machines in the selected production company was presented. The OEE method (Overall Equipment Effectiveness) was used for the analysis. The selected company deals with the production of tapered roller bearings. The analysis of effectiveness was done for 17 automatic grinding lines working in the department of grinding rollers. Low level of efficiency of machines was affected by problems with the availability of machines and devices. The causes of machine downtime on these lines was also analyzed. Three basic causes of downtime were identified: no kanban card, diamonding, no operator. Ways to improve the use of these machines were suggested. The analysis takes into account the actual results from the production process and covers the period of one calendar year.

THE INFLUENCE OF HOUSING ARRANGEMENT AND INTERFERENCE ON PRELOAD AND THEORETICAL LIFETIME OF A SYSTEM OF TAPER ROLLER BEARINGS OF A HIGH SPEED SHAFT OF A WIND TURBINE GEARBOX

A system of two taper roller bearings can carry loads with a high ratio of axial load to radial load. Such a system was proposed for a wind turbine gearbox following the poor durability of original bearing design with the aim of increasing durability. Because of size limits, a proposed system is composed of two different taper roller bearings. Standard manufacturers’ catalogues do not provide information on recommended preload or clearance conditions or the durability as a function of pre-load. That was the reason why durability was calculated on the basis of software provided by one of the manufacturers. The analysis presented in the paper shows the relationship between bearing fits, preload values, and the theoretical durability of the bearing.

Research on Distribution of Internal Load of Tapered Roller Bearing Used in Axle Box of High Speed Train

Three methods to calculate distribution of internal load in tapered roller bearing are introduced in the present paper. Distributions of internal load in tapered roller bearing used in axle box of High Speed Train have been calculated by continuous function model (conventional method), discrete function model method and finite element method according to the internal load distribution theory of rolling bearing. The results of three methods show that the pattern of the internal load distributions is same, but the accuracy is not same. The accuracy of radial load of the bearing with finite element method is highest, the accuracy with discrete model method is higher and the accuracy with discrete model method is lowest. The discrete function model is not only with the higher accuracy but also convenient to be used widely in practice through the program of dichotomie numerical method.

Ultrasonic-based monitoring of tapered roller bearings in frequency and time domains

espanolEn este articulo se utiliza la senal de ultrasonido para detectar fallas incipientes en rodamientos conicos. Las fallas estudiadas se ubican en la pista externa, interna, canastilla y elementos rodantes. Estas fallas se implementan en cada ubicacion para emular tres niveles de severidad distintos. El analisis de la senal de ultrasonido se realiza usando los parametros de curtosis y RMS, en el dominio tiempo, y la densidad espectral, usando el periodograma promediado de Welch, en el domino de la frecuencia. Aunque no fue posible ubicar la falla, el parametro RMS presenta el mejor desempeno como variable a monitorear permitiendo detectar la condicion de falla y realizar una evaluacion cualitativa de la severidad de esta. EnglishIn this paper the ultrasonic signal is used for early failure detection in tapered roller bearings. The faults studied were localized in outer race, inner race, cage and the rolling elements. The implemented failures emulate three distinct levels of severity. The ultrasonic signal analysis is performed using time domain parameters i.e. kurtosis and RMS, and in the frequency domain using the power spectral density obtained by the Welch periodogram. Although none of the studied parameter was able to extract the fault location, the RMS parameter presents the best performance as a feature to monitor allowing to identify faulty conditions and evaluate qualitatively the severity of the fault.

Dynamic simulation for a tapered roller bearing considering a localized surface fault on the rib of the inner race

Vibration characteristics of a tapered roller bearing system will be significantly affected by a localized surface fault in the rib of the inner race. The operating condition for the tapered roller bearing system is always monitored to prevent serious failures from happening based on changes in the vibration characteristics. However, most of the previous works are focused on dynamic simulations for a localized surface fault in the race surface. A new dynamic simulation method for a tapered roller bearing with a localized surface fault on the rib of the inner race is proposed. The non-Hertzian contact of taper roller to races and rib is considered. The time-varying deflection excitation caused by the fault is formulated in the proposed method, as well as both the axial and radial contact deformation between the races and rollers. Effects of the axial load, radial load, and fault sizes on the vibration characteristics for the tapered roller bearing are analyzed. An experimental investigation is also developed to validate the proposed method. The results show that the proposed dynamic simulation method can formulate the vibration characteristics for the tapered roller bearing caused by the localized surface fault on the rib of the inner race, which may give some guidance for the tapered roller bearing condition monitoring and fault diagnosis, especially for the incipient localized surface fault.

Optimization of partially crowned roller profiles for tapered roller bearings

The roller profile plays a key role in the overall performance of roller bearings. In traditional profile design for roller bearings, the roller profile was often analyzed in terms of the bearing performance, particularly the fatigue life. However, the bearing dynamic stiffness and fatigue life were seldom considered simultaneously in the design of Tapered roller bearings (TRBs). Among the available roller profiles, the partially crowned roller profile has been acknowledged as one of the best from the viewpoint of the bearing fatigue life and stiffness characteristics. This paper presented a design optimization for the partially crowned roller profile to improve the performance of TRBs. Two profile parameters of rollers employed for TRBs including the central flat length and crown radius were investigated. The optimal design parameters for the roller profile were obtained in consideration of both bearing fatigue life and stiffness. The proposed design approach was useful and applicable for further geometrical optimization, manufacturing, and engineering application of rolling bearings.

Optimal Wavelet Selection for the Size Estimation of Manufacturing Defects of Tapered Roller Bearings with Vibration Measurement using Shannon Entropy Criteria

Fault diagnosis of bearings is essential in manufacturing to increase quality. Traditionally, fault diagnosis of tapered roller element bearings is performed by signal processing methods, which handle the nonstationary behaviour of the signal. The wavelet transform is an efficient tool for analysing the vibration signal of the bearings because it can detect the sudden changes and transient impulses in the signal caused by faults in the bearing elements. In this article, manufacturing faults on the outer ring of tapered roller bearings due to the grinding process in manufacturing are investigated. Nine different real values wavelets (Symlet-2, Symlet-5, Symlet-8, db02, db06, db10, db14, Meyer, and Morlet) are compared according to the Energy-to-Shannon-Entropy ratio criteria, and which is efficient for detecting the manufacturing faults is determined. Finally, experiments are carried out on a test rig for determining the geometrical size of the manufacturing faults with all wavelets directly from the vibration signature the result of db02, Symlet-5, and Morlet wavelets are presented. When modelling the bearing structure as an under-damped second-order mass-spring-damper mechanical system, its unit impulse response function is compared to the wavelets on the basis of their Energy-to-Shannon-Entropy ratio to determine the fault size from the vibration signal. The proposed technique has been successfully implemented for measuring defect widths. The maximum deviation in result has been found to be 4.12 % for the defect width which was verified with image analysis methods using an optical microscope and contact measurement.

Analysis of Dynamic Characteristics for a Tapered Roller Bearing Cage

Analysis of Dynamic Characteristics for a Tapered Roller Bearing Cage

Optimal design of tapered roller bearings for maximum rating life under combined loads

Using the relationships of the ISO 281 standard, this paper optimizes the internal dimensions of tapered roller bearings for maximum rating life. The bearing system addressed contains two identical bearings subjected to an arbitrary combination of centred radial and axial forces. It is shown that the basic rating life increases more than quadratically with the roller infill and the aspect ratio of the rollers, increases with the sixth power of the pitch diameter of the roller set and decreases with the third power of the applied radial force. Further, for any given ratio of axial to radial force, an optimal contact angle exists which maximizes the rating life of the bearing pair, irrespective of the actual bearing size and ratio of roller diameter to pitch diameter. The optimization procedure can either be used to design custom-made bearings or to select from manufacturers’ catalogues the bearing with the best contact angle for any assigned loading condition.

Improvement of Production Efficiency of Tapered Roller Bearing by Using Plant Simulation

Improvement of Production Efficiency of Tapered Roller Bearing by Using Plant Simulation