scholarly journals RESEARCH OF THE WEAR MECHANISM OF BEARING SEATS OF AUTOMOTOR-TRACTOR TRANSMISSIONS

2021 ◽  
Vol 16 (4) ◽  
pp. 71-79
Author(s):  
Yuriy Ivanschikov ◽  
Vasiliy Skovorodin ◽  
Yuriy Dobrohotov ◽  
Roman Andreev ◽  
Aleksandr Vasil'ev ◽  
...  
Keyword(s):  
Rolling Bearing ◽  
Practical Implementation ◽  
Main Role ◽  
Fretting Corrosion ◽  
Rolling Bearings ◽  
Limiting State ◽  
Interference Fit ◽  
Proposed Model ◽  
Seating Surface ◽  
Analytical Expressions

A significant number (up to 25%) of failures of automotive transmissions are associated with a loss of rigidity in the rolling bearings. One of the main reasons for the loss of stiffness in rolling bearings is a violation of the tightness of the bearing on the shaft and in the housing due to fretting corrosion. The paper presents the results of a study of the causes of fretting corrosion in bearing fits and the patterns of its development. The conditions promoting the occurrence of the fretting process are determined and the factors characterizing the nature and intensity of destruction of contacting surfaces during fretting corrosion are established. It was also found that the greatest influence on the occurrence and course of the fretting process is exerted by the specific load on the contact surface, the duration and frequency of its application, and the amplitude of the relative slip of the contacting surfaces. Analytical expressions for calculating the actual values of the listed factors of the fretting process in the coupling of the rolling bearing with the shaft are determined by the calculation method, and a mathematical model of its destruction is proposed. For the practical implementation of the described mechanism of destruction of the rolling bearing landing on the shaft as a result of fretting corrosion, an algorithm and a program have been developed to determine the limiting state of the bearing landings of automotive transmissions. Subsequent laboratory tests confirmed the adequacy of the proposed model. As an example, the results of modeling the limiting state of the rolling bearing of the intermediate shaft of the gearbox of the K-700A tractor and the ball bearing 313 are given. It is revealed that the main role in reducing the intensity of the fretting process, along with the hardness of the shaft, is played by the roughness of its seating surface. In particular, a decrease in the roughness parameters from Ra = 2.0 µm to Ra = 0.5 µm at the same hardness HRC48 and an interference fit in N = 24 µm leads to an increase in the joint resource by 1.5 times

Dynamic asymptotic model of rolling bearings with a pitting fault based on fractional damping

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yunlong Li ◽  
Zhinong Li ◽  
Dong Wang ◽  
Zhike Peng
Keyword(s):  
Fractional Calculus ◽  
Dynamic Characteristics ◽  
Rolling Bearing ◽  
Integral Calculus ◽  
Rolling Bearings ◽  
Fractional Damping ◽  
Content Type ◽  
Asymptotic Models ◽  
Proposed Model ◽  
Different Parts

PurposeThe purpose of this paper is to discuss the asymptotic models of different parts with a pitting fault in rolling bearings.Design/methodology/approachFor rolling bearings with a pitting fault, the displacement deviation between raceways and rolling elements is usually considered to vary instantaneously. However, the deviation should change gradually. Based on this shortcoming, the variation rule and calculation method of the displacement deviation are explored. Asymptotic models of different parts with a pitting fault are discussed, respectively. Besides, rolling bearing systems have prominent fractional characteristics unconsidered in the traditional models. Therefore, fractional calculus is introduced into the modeling of rolling bearings. New dynamic asymptotic models of different parts with a pitting fault are proposed based on fractional damping. The numerical simulation is performed based on the proposed model, and the dynamic characteristics are analyzed through the bifurcation diagrams, trajectory diagrams and frequency spectrograms.FindingsCompared with the model based on integral calculus, the proposed model can better reflect the periodic characteristics and fault characteristics of rolling bearings. Finally, the proposed model is verified by the experiment. The dynamic characteristics of rolling bearings at different rotating speeds are analyzed. The experimental results are consistent with the simulation results. Therefore, the proposed model is effective.Originality/value(1) The above models are idealized, i.e. the local pitting fault is treated as a rectangle. When a component comes into contact with the fault, the displacement deviation between the component and the fault component immediately releases if the component enters the fault area and restores if the component leaves. However, the displacement deviation should change gradually. Only when the component touches the fault bottom, the displacement deviation reaches the maximum. (2) Due to the material's memory and fluid viscoelasticity, rolling bearing systems exhibit significant fractional characteristics. However, the above models are all proposed based on integral calculus. Integral calculus has some local characteristics and is not suitable for describing historical dependent processes. Fractional calculus can better describe the essential characteristics of the system.

Modeling and experimental study of power losses in a rolling bearing

2019 ◽  
Vol 234 (8) ◽  
pp. 1332-1351 ◽  
Author(s):  
Guglielmo Giannetti ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Alessandro Ridolfi ◽  
Zhiyong Shi ◽  
...  
Keyword(s):  
High Performance ◽  
Fluid Dynamic ◽  
Rolling Bearing ◽  
Power Losses ◽  
Rolling Bearings ◽  
Proposed Model ◽  
Improved Model ◽  
Bearing Behavior ◽  
Very High ◽  
Good Agreement

Due to the growing demand for very high performance in aeronautical mechanisms and systems, particular attention must be paid on the bearing modeling and design. In this framework, a fundamental role is played by high peripheral speed and very low power losses. Looking toward this direction, this paper presents an improved model of rolling bearings able to describe the system dynamic behavior and the important effect of different kinds of power losses (friction losses, fluid dynamic losses, etc.). The proposed model is characterized by a high numerical efficiency and allows the investigation of the rolling bearing behavior both under transient and steady conditions. A comparison between the experimental and simulated results is also presented in this paper. The analysis of the results is encouraging and shows a good agreement between experiments and model simulations.

Efficiency of application of the phase-chronometric method and neurodiagnostics for monitoring the degradation of rolling bearings during operation

2020 ◽  
pp. 43-50
Author(s):  
A.S. Komshin ◽  
K.G. Potapov ◽  
V.I. Pronyakin ◽  
A.B. Syritskii
Keyword(s):  
Life Cycle ◽  
Wavelet Analysis ◽  
Metrological Support ◽  
Rolling Bearing ◽  
Technical Condition ◽  
Measurement Information ◽  
Rolling Bearings ◽  
Vibration Diagnostics ◽  
Bearing Life ◽  
Alternative Approach

The paper presents an alternative approach to metrological support and assessment of the technical condition of rolling bearings in operation. The analysis of existing approaches, including methods of vibration diagnostics, envelope analysis, wavelet analysis, etc. Considers the possibility of applying a phase-chronometric method for support on the basis of neurodiagnostics bearing life cycle on the basis of the unified format of measurement information. The possibility of diagnosing a rolling bearing when analyzing measurement information from the shaft and separator was evaluated.

The Effect of the EHD Pressure Spike on Rolling Bearing Fatigue

1987 ◽  
Vol 109 (3) ◽  
pp. 444-450 ◽  
Author(s):  
L. Houpert ◽  
E. Ioannides ◽  
J. C. Kuypers ◽  
J. Tripp
Keyword(s):  
Pressure Distribution ◽  
High Stress ◽  
Surface Damage ◽  
Rolling Bearing ◽  
Shear Stresses ◽  
Stress Concentrations ◽  
Surface Layers ◽  
Rolling Bearings ◽  
Life Model ◽  
Pressure Spike

A recently proposed fatigue life model for rolling bearings has been applied to the study of lifetime reduction under conditions conducive to microspalling. The presence of a spike in the EHD pressure distribution produces large shear stresses localized very close to the surface which may account for early failure. This paper describes a parametric study of the effect of such spikes. Accurate stress fields in the volume are calculated for simulated pressure spikes of different height, width and position relative to a Hertzian pressure distribution, as well as for different lubricant traction coefficients and film thicknesses. Despite the high stress concentrations in the surface layers, reductions in life predicted by the model are modest. Typically, the pressure spike may halve the life, with the implication that subsurface fatigue still dominates. In corroboration of this prediction, preliminary experimental work designed to reproduce microspalling conditions shows that microindents due to overrolling particles are a much more common form of surface damage than microspalling.

Contribution to Rolling Bearing Reliability Modeling

2011 ◽  
Vol 110-116 ◽  
pp. 2497-2503 ◽  
Author(s):  
Zdenek Vintr ◽  
Michal Vintr
Keyword(s):  
Operating Time ◽  
Rolling Bearing ◽  
Time To Failure ◽  
Rolling Bearings ◽  
Mean Time To Failure ◽  
Reliability Modeling ◽  
Time Between Failures ◽  
Large Groups ◽  
Mean Time

Rolling bearings are usually considered to be non-repaired items the reliability of which is characterized by mean time to failure, or so called basic rating life. Reliability describes these parameters well in case the bearings are used in operation up to the very time the failure occurs, or during the time corresponding with basic rating life. In case of railway applications the bearings are often used in large groups and are preventively replaced after much shorter operating time as compared with their basic rating life. In the article there is a model which enables us to describe the bearings reliability in this specific case and to specify a number of failures which might be expected from a group of bearings during operating time, or to determine mean operating time between failures of bearings.

Rolling Bearing Parametric Excitation of a Jeffcott Rotor System

2020 ◽  
Author(s):  
Ghasem Ghannad Tehrani ◽  
Chiara Gastaldi ◽  
Teresa Maria Berruti
Keyword(s):  
Parametric Excitation ◽  
Rotational Speed ◽  
Input Parameter ◽  
Equations Of Motion ◽  
Harmonic Balance Method ◽  
Rolling Bearing ◽  
Mean Value ◽  
Hertzian Contact ◽  
Rolling Bearings ◽  
Jeffcott Rotor

Abstract Rolling bearings are still widely used in aeroengines. Whenever rotors are modeled, rolling bearing components are typically modeled using springs. In simpler models, this spring is considered to have a constant mean value. However, the rolling bearing stiffness changes with time due to the positions of the balls with respect to the load on the bearing, thus giving rise to an internal excitation known as Parametric Excitation. Due to this parametric excitation, the rotor-bearings system may become unstable for specific combinations of boundary conditions (e.g. rotational speed) and system characteristics (rotor flexibility etc.). Being able to identify these instability regions at a glance is an important tool for the designer, as it allows to discard since the early design stages those configurations which may lead to catastrophic failures. In this paper, a Jeffcott rotor supported and excited by such rolling bearings is used as a demonstrator. In the first step, the expression for the time–varying stiffness of the bearings is analytically derived by applying the Hertzian Contact Theory. Then, the equations of motion of the complete system are provided. In this study, the Harmonic Balance Method (HBM) is used to as an approximate procedure to draw a stability map, thus dividing the input parameter space, i.e. rotational speed and rotor physical characteristics, into stable and unstable regions.

Analysis of the Behaviour of Rolling Bearings in Contaminated Oil Using Some Condition Monitoring Techniques

2006 ◽  
Vol 220 (5) ◽  
pp. 447-453 ◽  
Author(s):  
T Akagaki ◽  
M Nakamura ◽  
T Monzen ◽  
M Kawabata
Keyword(s):  
Vibration Analysis ◽  
Wear Debris ◽  
Friction And Wear ◽  
Rolling Bearing ◽  
Rolling Bearings ◽  
Deep Groove ◽  
Deep Groove Ball Bearing ◽  
Observation Results ◽  
Wear Debris Analysis ◽  
Worn Surfaces

Friction and wear behaviours of rolling bearing in contaminated oil containing white-fused alumina particles were studied. The friction and wear processes were monitored using wear debris analysis, such as ferrography and spectrometric oil analysis program, and vibration analysis. Test bearing was a deep groove ball bearing (6002P5); Wear debris and worn surfaces of the bearing components were observed with a scanning electron microscope (SEM). It was found that the friction coefficient in the contaminated oil became lower by about 0.001 than that in the new oil for the large contaminants. The results of wear debris analysis showed that the large contaminants caused the high wear rate in the bearing. Three types of wear debris were commonly observed: thread-like debris, cutting chip debris, and plate-like debris. On the basis of the SEM observation results of the worn surfaces, wear mechanisms of these wear debris were discussed. The results of vibration analysis showed that the probability density function of vibration waveform was normal distribution in both the new and contaminated oils. In the contaminated oil, it changed depending on the contaminant size and the runtime, i.e. the progress of wear in the bearing. The result of wear debris analysis was related to that of vibration analysis and discussed.

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