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.

A dynamic response test rig of a full-scale rotor–journal bearing system

2018 ◽  
Vol 233 (4) ◽  
pp. 649-659
Author(s):  
Qiang Li ◽  
Shuo Zhang ◽  
Yujun Wang ◽  
Weiwei Xu ◽  
Zhenbo Wang
Keyword(s):  
Dynamic Response ◽  
Natural Frequency ◽  
Journal Bearing ◽  
Dynamic Balance ◽  
Journal Bearings ◽  
Full Scale ◽  
Test Rig ◽  
Field Dynamic ◽  
Bearing Structure ◽  
Bearing System

A design strategy of a test rig for the dynamic behavior of a rotor supported by two full-scale journal bearings was proposed. A special part, called “intermediate”, was set up to allow the convenient changing of the bearing structure. An electromagnetic exciter was used to obtain the natural frequency, and software running on the Microsoft Visual C++6.0 operating platform was programmed for signal acquisition and analysis. Then, the test rig was constructed. The field dynamic balance and natural frequency testing were carried out. The journal orbits and frequency spectrums were used to measure the dynamic response of different structure full-scale journal bearings. The experimental results showed that an acceptable balance effect was achieved after the field dynamic balance. The natural frequency of the rig agreed with the numerical results. Stability was improved through changing the bearing structure. This revealed that this rig can effectively test the dynamic behavior of a rotor supported by a full-scale journal bearing system, which is critical to the design of journal bearings.

Identification of oil film coefficients of large journal bearings on a full scale journal bearing test rig

1997 ◽  
Vol 30 (11) ◽  
pp. 789-793 ◽  
Author(s):  
G.D. Jiang ◽  
H. Hu ◽  
W. Xu ◽  
Z.W. Jin ◽  
Y.B. Xie
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Full Scale ◽  
Test Rig ◽  
Oil Film

Performance of Stern Tube Bearings under Different Lubrication and Operating Conditions

2009 ◽  
Author(s):  
Jan H. Andersen ◽  
Hiroyuki Sada ◽  
Seiji Yamajo
Keyword(s):  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Water Soluble ◽  
Analysis Tool ◽  
Test Rig ◽  
Experimental Performance ◽  
Shaft Alignment ◽  
Alignment Analysis

This paper presents the results of an investigation into the theoretical and experimental performance of oil lubricated journal bearings. DNV has developed a new calculation tool for the analysis of journal bearing performance as part of shaft alignment analysis. The results of the calculation tool have been compared to other research and analysis methods under static and dynamic conditions. In addition, white metal bearings were tested with decreasing Sommerfeld number until loss of hydrodynamic lubrication. The experiments were carried out in a bearing test rig and with three different lubricants, normal mineral oil, emulsifying oil, and water-soluble oil. The tests were done with increasing water content in the lubricant. Results from the test were compared with calculation using the DNV analysis tool.

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.

Researches on Friction Performance of Water-Lubricated Polymer Composite Journal Bearings Based on Experiments

2014 ◽  
Vol 711 ◽  
pp. 57-60
Author(s):  
Geng Yuan Gao ◽  
Zhong Wei Yin ◽  
Dan Jiang ◽  
Xiu Li Zhang
Keyword(s):  
Carbon Fiber ◽  
Polymer Composite ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Journal Bearings ◽  
Test Rig ◽  
Friction Performance ◽  
Steel Sleeve ◽  
Almost All ◽  
The Given

A composite which is PTFE as a matrix with PEEK and carbon fiber as fillers is developed to fabricate the bush of water-lubricated journal bearings. The bush is fabricated with a new structure that a relatively large straight groove is opened in its upper part. A water-lubricated journal bearing made up of the bush and a steel sleeve is studied using purposed-built test rig. It is shown that the test bearing operates under hydrodynamic lubrication for almost all of the given conditions. The composite developed in the work is a promising material for water-lubricated journal bearings, and the new structure can be well used in water-lubricated journal bearings.

Stabilization Method for Small-Bore Journal Bearings Utilizing Starved Lubrication

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Hiromu Hashimoto ◽  
Masayuki Ochiai
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Control Mechanism ◽  
Journal Bearings ◽  
Test Rig ◽  
Stabilization Method ◽  
Speed Test ◽  
Nonlinear Motion ◽  
Starved Lubrication ◽  
Theoretical Results

This paper describes the stabilization method for small-bore circular journal bearings using starved lubrication. First, we describe the experimental examination to confirm the effect of supply oil conditions on stability of circular journal bearing by using a high-speed test rig. Then, the theoretical model considering the effect of amount of supply oil is discussed. Journal center trajectories are calculated by nonlinear motion analysis under various conditions. The theoretical results agree well with the experimental ones for three types of supply oil conditions and the mechanism of the stabilization by using the starved lubrication for small-bore journal bearings is clarified. Moreover, we suggest a supply oil control mechanism to stabilize the journal bearing using starved lubrication. Finally, the effectiveness of the proposed control mechanism on stability for high-speed small-bore journal bearings is verified experimentally.

scholarly journals Numerical Study of a Journal Bearing with Scratches: Validation with Literature and Comparison with Experimental Data

Lubricants ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 61
Author(s):  
Anh T. Vo ◽  
Michel Fillon ◽  
Jean Bouyer
Keyword(s):  
Scientific Literature ◽  
Journal Bearing ◽  
Numerical Study ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Test Rig ◽  
Numerical Studies ◽  
Clear Idea ◽  
Volume Method ◽  
Good Agreement

The lifespan of journal bearings is directly related to the operating conditions they have to face and reducing their maintenance intervals allows one to have a clear idea about their performance when issues occur. The presence of scratches on one of its surfaces degrades the performance of a journal bearing. These effects have already been assessed in experiments; however, numerical studies on this subject are still scarce. This work develops a numerical thermohydrodynamic (THD) program using the finite volume method to simulate the effects of scratches on the performance of journal bearings. To test the validity of the program, the numerical results are compared with the scientific literature and with experimental measurements conducted using the Pprime Institute journal bearing test rig. Some minor discrepancies are observed, but the overall results are in good agreement.

Improving Tilting-Pad Journal Bearing Predictions: Part I—Model Development and Impact of Rotor-Excited Versus Bearing-Excited Impedance Coefficients

2012 ◽  
Author(s):  
Jason C. Wilkes ◽  
Dara W. Childs
Keyword(s):  
Journal Bearing ◽  
Reaction Force ◽  
Model Development ◽  
Journal Bearings ◽  
Test Rig ◽  
Tilting Pad ◽  
Force Components ◽  
Rotor Journal ◽  
Tilting Pad Journal Bearing ◽  
Tilting Pad Journal Bearings

The floating-bearing-test-rig concept was initially developed by Glienicke in 1966 and has since been used to test many tilting-pad journal bearings (TPJBs). The impedances measured during these tests have been compared to rotor/journal perturbed impedance predictions. Since the inertial acceleration of a pad is different for bearing perturbed and rotor perturbed motions, the bearing’s reaction force components for bearing perturbed and journal perturbed motions will also differ. An understanding of how bearing perturbed and rotor perturbed impedances differ is needed to assess the validity of past, present, and future comparisons between TPJB test data and predictions. A new TPJB perturbation model is developed including the effects of angular, radial, and transverse pad motion and changes in pad clearance due to pad bending compliance. Though all of these pad variables have previously been included in different analyses, there are no publications containing perturbations of all four variables. In addition, previous researchers have only perturbed the rotor, while both the bearing and rotor motions are perturbed in the present analysis. The applicability of comparing rotor-perturbed bearing impedance predictions to impedances measured on a bearing-perturbed test rig is assessed by comparing rotor perturbed and bearing perturbed impedance predictions for an example bearing.

Investigation of Friction Power Losses in Automotive Journal Bearings

2014 ◽  
Vol 66 (3) ◽  
Author(s):  
H. Allmaier ◽  
D. E. Sander ◽  
C. Knauder ◽  
F. M. Reich
Keyword(s):  
Internal Combustion Engines ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Power Losses ◽  
Test Rig ◽  
Friction Power ◽  
Starting Point ◽  
Thermodynamical Behavior

Journal bearings are used in a large number of critical positions in automotive internal combustion engines (ICE) and contribute a major contribution to the total friction power losses in these engines. These reasons motivate in addition the accurate and reliable simulation of the operating conditions and friction power losses in journal bearings. In this work the lubrication of journal bearings is investigated in detail using detailed rheological lubricant models that include the piezoviscous effect. To describe mixed lubrication realistically in the simulation, a sophisticated contact model is employed together with measured surface roughness data from journal bearings. Starting point is an extensive thermo-elastohydrodynamic (TEHD) simulation, which yields important insights into the thermodynamical behavior of the lubricant film in journal bearings. From these results, a powerful isothermal elastohydrodynamic (EHD) simulation model is derived that calculates the oil temperature for the simulation from two easily accessible experimental temperatures. The capabilities of the presented simulation methods are compared to extensive experimental measurements performed on a journal bearing test-rig, which show excellent agreement.

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