scholarly journals Friction and Wear in Automotive Journal Bearings Operating in Today’s Severe Conditions

10.5772/64247 ◽  
2016 ◽  
Author(s):  
David E. Sander ◽  
Hannes Allmaier ◽  
Hans-Herwig Priebsch
Keyword(s):  
Friction And Wear ◽  
Journal Bearings

scholarly journals Friction and Wear Monitoring Methods for Journal Bearings of Geared Turbofans Based on Acoustic Emission Signals and Machine Learning

Lubricants ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 29 ◽  
Author(s):  
Noushin Mokhtari ◽  
Jonathan Gerald Pelham ◽  
Sebastian Nowoisky ◽  
José-Luis Bote-Garcia ◽  
Clemens Gühmann
Keyword(s):  
Machine Learning ◽  
Acoustic Emission ◽  
Friction And Wear ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Wear Volume ◽  
Time Frequency ◽  
Ae Signal ◽  
Ae Signals

In this work, effective methods for monitoring friction and wear of journal bearings integrated in future UltraFan® jet engines containing a gearbox are presented. These methods are based on machine learning algorithms applied to Acoustic Emission (AE) signals. The three friction states: dry (boundary), mixed, and fluid friction of journal bearings are classified by pre-processing the AE signals with windowing and high-pass filtering, extracting separation effective features from time, frequency, and time-frequency domain using continuous wavelet transform (CWT) and a Support Vector Machine (SVM) as the classifier. Furthermore, it is shown that journal bearing friction classification is not only possible under variable rotational speed and load, but also under different oil viscosities generated by varying oil inlet temperatures. A method used to identify the location of occurring mixed friction events over the journal bearing circumference is shown in this paper. The time-based AE signal is fused with the phase shift information of an incremental encoder to achieve an AE signal based on the angle domain. The possibility of monitoring the run-in wear of journal bearings is investigated by using the extracted separation effective AE features. Validation was done by tactile roughness measurements of the surface. There is an obvious AE feature change visible with increasing run-in wear. Furthermore, these investigations show also the opportunity to determine the friction intensity. Long-term wear investigations were done by carrying out long-term wear tests under constant rotational speeds, loads, and oil inlet temperatures. Roughness and roundness measurements were done in order to calculate the wear volume for validation. The integrated AE Root Mean Square (RMS) shows a good correlation with the journal bearing wear volume.

scholarly journals Friction and Wear Performance of Various Polymer Coatings for Journal Bearings under Stop Start Sliding

Lubricants ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Florian Summer ◽  
Florian Grün ◽  
Emma R Ravenhill
Keyword(s):  
Friction And Wear ◽  
Combustion Engine ◽  
Polymer Coatings ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Wear Performance ◽  
Set Up ◽  
Many Core ◽  
The Given

Increasing environmental legislation and demands for improved fuel economy performance have resulted in the introduction of various measures to optimize the internal combustion engine. Many of these actions significantly change the operating conditions of the engines and bring with them new challenges that original engine manufacturers (OEMs) have to solve. One example is stop start technology, which changes the operation of many core parts of engines such as journal bearings. Hence, the current paper deals with this topic. In particular, different polymer coated bearings have been studied regarding their friction and wear performance under stop start sliding. Detailed material characterization of the materials was carried out using light microscopy and scanning electron microscopy. Furthermore, tribometric tests were conducted under controlled and similar conditions on a TE92 tribometer using a bearing segment test set up. The results show that the various polymer coated bearings tested provide enhanced friction and wear performance in comparison to other bearing types (e.g., lead-based electroplated) and that friction and wear performance differs also among them. In this regard, a higher amount of solid lubricant fillers and a dense filler structure appears to be beneficial under the given test conditions.

Testing of Full Scale Composite Journal Bearings for Offshore Underwater Applications

2015 ◽  
Author(s):  
R. C. Dragt ◽  
W. van den Heuvel ◽  
E. R. M. Gelinck ◽  
H. M. Slot
Keyword(s):  
Structural Dynamics ◽  
Friction And Wear ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Full Scale ◽  
Test Rig ◽  
Offshore Industry ◽  
Full Scale Tests ◽  
Rate Development ◽  
Wear Tests

In the offshore industry, fibre reinforced sliding journal bearings are increasingly used due to their low-maintenance and self-lubricating characteristics. To be able to use the bearings in the rough offshore environment, under heavy loading, full scale tests are essential to assess the friction and wear rate development during use. For this purpose, two full scale wear tests were performed on composite sliding journal bearings of 300 mm in diameter. These tests were performed at the laboratory of TNO Structural Dynamics in Delft, The Netherlands, over a period of eight months. For this purpose, a test rig was designed in which a shaft runs through the journal bearing. The latter is loaded in the range 50 to 700 kN and the shaft is given triangle-like cyclic displacements. To be able to test under realistic conditions, the bearing is constantly submerged in flowing seawater. Forces, displacements and temperatures were constantly monitored to manage the system and determine the parameters. Besides a description of the test rig, a rationale of choices made, observations during testing and detailed cycle-by-cycle friction characteristics are presented, next to generalized trends for the wear and Coefficients of Friction (CoFs) under the various loading conditions.

The influences of lubricant groove shape on the tribological properties of journal bearing under the grease lubrication conditions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shicheng Yan ◽  
Yahong Xue ◽  
Liming Wei ◽  
Zhanchao Wang
Keyword(s):  
Friction And Wear ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Grease Lubrication ◽  
Lubricating Grease ◽  
Content Type ◽  
Blind Hole ◽  
Swing Angle ◽  
Straight Line ◽  
Load Carrying

Purpose This paper aims to elucidate the effects of lubricant groove shape, vertical load, swing angle and grease injection cycle on the friction and wear performances of journal bearings under the grease lubrication condition. Design/methodology/approach Three different types of lubricant grooves, namely, numeral eight-shaped, axial straight line-shaped and circular blind hole-shaped, were designed and machined in the bearing bush of journal bearings. The tribological behaviors of these journal bearings were investigated on the self-developed reciprocating swing friction and wear tester. Experimental data including the friction coefficient, the friction temperature, the wear loss and wear time were analyzed in detail. The wear morphologies of friction pairs were observed by scanning electron microscope and confocal laser scanning microscope. Findings The load carrying capacity and service life of the journal bearing with circular blind hole-shaped lubricant grooves are not affected. However, the load carrying capacities of journal bearings with numeral eight-shaped and axial straight line-shaped lubricant grooves are declined. The coverage areas of lubricating grease in the bearing bush are associated with the swing angle. The smaller the swing angle is, the more limited the coverage areas of lubricating grease get. Among these journal bearings, the maintenance-free time of journal bearing with circular blind hole-shaped lubricant grooves is the longest because of its large grease storage capacity. Originality/value The journal bearing with circular blind hole-shaped lubricant grooves exhibits the excellent antifriction and wear-resistant properties, making it suitable for the application in the low-speed and heavy-load engineering conditions.

Friction and Wear Characteristics of Bearing Materials Under Boundary Lubricated Conditions

1979 ◽  
Vol 101 (4) ◽  
pp. 474-480
Author(s):  
Yoshiki Doi ◽  
Tutom Haba
Keyword(s):  
Friction Coefficient ◽  
Film Thickness ◽  
Friction And Wear ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Load Parameter ◽  
Empirical Equations ◽  
Flash Temperature ◽  
Bearing Materials ◽  
Friction And Wear Characteristics

This paper presents the results of tests performed with journal bearings with seven bearing materials, at a variety of loads and rotational speeds. On the basis of these results some empirical equations for predicting the behavior of boundary lubricated journal bearings are proposed. It is demonstrated that a noncontact parameter, that is, the ratio of elastohydrodynamic film thickness to the combined roughness of the two mating surfaces, plays the same important role in the behavior of the boundary lubricated journal bearing as in rolling-sliding elements. The friction coefficient is represented by the noncontact parameter and a nondimensional load parameter, besides by material constants, unless preseizure occurs. A critical flash temperature can predict the preseizure. Moreover it is shown that the correlation between the specific wear and the friction coefficient is close at any operating condition.

Analytical Electron Microscopy of Ion-Implanted Metals

1985 ◽  
Vol 43 ◽  
pp. 282-285
Author(s):  
D.I. Potter ◽  
M. Ahmed ◽  
K. Ruffing
Keyword(s):  
Electron Microscopy ◽  
Ion Implantation ◽  
Friction And Wear ◽  
Analytical Electron Microscopy ◽  
Chemical Compositions ◽  
Surface Chemical ◽  
Near Surface ◽  
The Past ◽  
Analytical Electron ◽  
Property Changes

Ion implantation, used extensively for the past decade in fabricating semiconductor devices, now provides a unique means for altering the near-surface chemical compositions and microstructures of metals. These alterations often significantly improve physical properties that depend on the surface of the material; for example, catalysis, corrosion, oxidation, hardness, friction and wear. Frequently the mechanisms causing these beneficial alterations and property changes remain obscure and much of the current research in the area of ion implantation metallurgy is aimed at identifying such mechanisms. Investigators thus confront two immediate questions: To what extent is the chemical composition changed by implantation? What is the resulting microstructure? These two questions can be investigated very fruitfully with analytical electron microscopy (AEM), as described below.

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