Improving Rolling Element Bearing Thermal Compliance Through In Situ Cooling

2011 ◽  
Author(s):  
E. Y. A. Wornyoh ◽  
D. K. Patel ◽  
Luke Schuessler ◽  
A. B. Francis ◽  
C. S. Garnett
Keyword(s):  
Cooling System ◽  
Frictional Heating ◽  
Rolling Element Bearing ◽  
Outer Race ◽  
Continuous Cooling ◽  
Rolling Element ◽  
The Coefficient Of Friction ◽  
Element Bearing ◽  
Cooling Coil

In this study a novel in situ rolling element bearing (REB) lubricant cooling system is developed that provides a continuous cooling of the bearing outer race. In the design the stationary outer race is expanded to accommodate a cooling coil for the continuous cooling of the lubricant and the outer race. Water is used as the coolant While Amsoil 75W-90 Severe Gear® oil is used as a lubricant. Heat generated during the test run is removed by the coolant flowing through the cooling coil. The tribological effects at the speeds of the cooling test were evaluated using block-on-ring tribometer tests. Results from the experiments indicate that in the absence of cooling the temperature of the bearing outer race rises while cooling dramatically lowers the temperature. Also, the coefficient of friction increases with increasing speed. As such, in situ cooling that leads to reduced operational temperature minimizes lubricant degradation that can result from uncontrolled frictional heating.

An In Situ Mechanism for the Optimal Cooling of Oil-Lubricated Rolling Element Bearings and Planetary Gear Systems

2011 ◽  
Author(s):  
E. Y. A. Wornyoh ◽  
D. K. Patel ◽  
L. D. Schuessler
Keyword(s):  
Heat Exchanger ◽  
Planetary Gear ◽  
Rolling Element Bearing ◽  
Lubricant Degradation ◽  
Premature Failure ◽  
Outer Race ◽  
Rolling Element ◽  
Frictional Dissipation ◽  
Cooling Coil

A major detriment to reliable and sustainable operation of rotational equipment has been extensively linked to high thermal loads from frictional dissipation. Frictional dissipation in critical tribological components such as bearings and gears results in lubricant degradation and subsequent subpar thermal performance. In this study, a novel in situ lubricant cooling system is used to provide a continuous cooling of these critical tribo-components. Experiments were conducted using rolling element bearing (REB) and planetary gear system (PGS) sets. The stationary outer race of a REB was used to accommodate a cooling coil in a heat exchange-like arrangement. Similarly, the stationary outer ring of the PGS housed a cooling coil in another heat exchanger-like arrangement. Use of the heat exchanger arrangements assured continuous in situ cooling to remove the heat generated in the tribological REB and PGS. Water was used as the coolant while Amsoil 75W-90 Severe Gear® oil was the lubricant used. Highly conductive copper coils surrounded the REB or PGS and the coolant was circulated through the coils to remove the heat from the outer bearing race and ring gear. The hot lubricant rejects heat by convection into the outer race thereby limiting lubricant degradation. The incidence of wear and premature failure are also minimized. So far results from this experimental study show that heat generation is significantly minimized in bearings and gears when cooled in situ. This preliminary study has offered important insight for more rigorous follow-on studies.

scholarly journals Estimation of the Defect Width on the Outer Race of a Rolling Element Bearing under Time-Varying Speed Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Guang-Quan Hou ◽  
Chang-Myung Lee
Keyword(s):  
Research Work ◽  
Defect Size ◽  
Remaining Useful Life ◽  
Rolling Element Bearing ◽  
Time Varying ◽  
Entry And Exit ◽  
Outer Race ◽  
Time Frequency ◽  
Rolling Element ◽  
Element Bearing

Fault diagnosis and failure prognostics for rolling element bearing are helpful for preventing equipment failure and predicting the remaining useful life (RUL) to avoid catastrophic failure. Spall size is an important fault feature for RUL prediction, and most research work has focused on estimating the fault size under constant speed conditions. However, estimation of the defect width under time-varying speed conditions is still a challenge. In this paper, a method is proposed to solve this problem. To enhance the entry and exit events, the edited cepstrum is used to remove the determined components. The preprocessed signal is resampled from the time domain to the angular domain to eliminate the effect of speed variation and measure the defect size of a rolling element bearing on outer race. Next, the transient impulse components are extracted by local mean decomposition. The entry and exit points when the roller passes over the defect width on the outer race were identified by further processing the extracted signal with time-frequency analysis based on the continuous wavelet transform. The defect size can be calculated with the angle duration, which is measured from the identified entry and exit points. The proposed method was validated experimentally.

Advanced Rolling-Element Bearing Diagnostics Based on Cyclic Spectral Analysis

2007 ◽  
Vol 347 ◽  
pp. 265-270
Author(s):  
Jerome Antoni ◽  
Roger Boustany
Keyword(s):  
Background Noise ◽  
Rolling Element Bearing ◽  
Outer Race ◽  
Spectral Signatures ◽  
Bearing Diagnostics ◽  
Rolling Element ◽  
Cyclical Behaviour ◽  
Element Bearing ◽  
Incipient Fault ◽  
Inner Race

Rolling-element bearing vibrations are random cyclostationary, that is they exhibit a cyclical behaviour of their statistical properties while the machine is operating. This property is so symptomatic when an incipient fault develops that it can be efficiently exploited for diagnostics. This paper gives a synthetic but comprehensive discussion about this issue. First, the cyclostationarity of bearing signals is proved from a simple phenomenological model. Once this property is established, the question is then addressed of which spectral quantity can adequately characterise such vibration signals. In this respect, the cyclic coherence - and its multi-dimensional extension in the case of multi-sensors measurements -- is shown to be twice optimal: first to evidence the presence of a fault in high levels of background noise, and second to return a relative measure of its severity. These advantages make it an appealing candidate to be used in adverse industrial environments. The use and interpretation of the proposed tool are then illustrated on actual industrial measurements, and a special attention is paid to describe the typical "cyclic spectral signatures" of inner race, outer race, and rolling-element faults.

scholarly journals Analytical model and spectral characteristics of acoustic emission signal produced by localized fault of rolling element bearing

2021 ◽  
Vol 39 (4) ◽  
pp. 831-838
Author(s):  
Fazhong Li ◽  
Zengshui He ◽  
Lin Zhang ◽  
Anbo Ming ◽  
Yongsheng Yang
Keyword(s):  
Acoustic Emission ◽  
Analytical Model ◽  
High Frequency ◽  
Spectral Characteristics ◽  
Rolling Element Bearing ◽  
Outer Race ◽  
Emission Signal ◽  
Rolling Element ◽  
Excitation Mechanisms ◽  
Element Bearing

The accurate description of acoustic emission signals produced by the localized fault of a rolling element bearing plays an important role in its feature extraction and analysis. This paper analyzes the excitation mechanisms and develops the analytical model of acoustic emission signals produced when the rolling element bearing passes across the localized fault on the inner or outer race. Based on the analytical model, the spectral characteristics are discussed substantially. Simulations and experiments are carried out to validate the efficacy of the model developed in the paper. The experimental results show that the response signal thus produced has two parts. The first one is produced by the entry of the rolling element bearing, while the other is produced by the departure of the rolling element bearing. The energy of both parts is concentrated around the resonance frequency of the acoustic emission transducer. Generally, the interval of adjacent acoustic emission events is not equivalent to each other and the corresponding spectrum is continuous in the high frequency band.

A fast and adaptive varying-scale morphological analysis method for rolling element bearing fault diagnosis

2012 ◽  
Vol 227 (6) ◽  
pp. 1362-1370 ◽  
Author(s):  
Changqing Shen ◽  
Qingbo He ◽  
Fanrang Kong ◽  
Peter W Tse
Keyword(s):  
Fault Diagnosis ◽  
Morphological Analysis ◽  
Rolling Element Bearing ◽  
Outer Race ◽  
Bearing Fault ◽  
Bearing Fault Diagnosis ◽  
Bearing Defect ◽  
Rolling Element ◽  
Element Bearing ◽  
Fault Characteristic

The research in fault diagnosis for rolling element bearings has been attracting great interest in recent years. This is because bearings are frequently failed and the consequence could cause unexpected breakdown of machines. When a fault is occurring in a bearing, periodic impulses can be revealed in its generated vibration frequency spectrum. Different types of bearing faults will lead to impulses appearing at different periodic intervals. In order to extract the periodic impulses effectively, numerous techniques have been developed to reveal bearing fault characteristic frequencies. In this study, an adaptive varying-scale morphological analysis in time domain is proposed. This analysis can be applied to one-dimensional signal by defining different lengths of the structure elements based on the local peaks of the impulses. The analysis has been first validated by simulated impulses, and then by real bearing vibration signals embedded with faulty impulses caused by an inner race defect and an outer race defect. The results indicate that by using the proposed adaptive varying-scale morphological analysis, the cause of bearing defect could be accurately identified even the faulty impulses were partially covered by noise. Moreover, compared to other existing methods, the analysis can be functioned as an efficient faulty features extractor and performed in a very fast manner.

scholarly journals A Novel Approach of Impulsive Signal Extraction for Early Fault Detection of Rolling Element Bearing

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Hu Aijun ◽  
Lin Jianfeng ◽  
Sun Shangfei ◽  
Xiang Ling
Keyword(s):  
Fault Detection ◽  
Finite Impulse Response ◽  
Rolling Element Bearing ◽  
Signal Extraction ◽  
Outer Race ◽  
Bearing Fault ◽  
Novel Approach ◽  
Rolling Element ◽  
Element Bearing ◽  
Early Fault Detection

The fault signals of rolling element bearing are often characterized by the presence of periodic impulses, which are modulated high-frequency harmonic components. The features of early fault in rolling bearing are very weak, which are often masked by background noise. The impulsiveness of the vibration signal has affected the identification of characteristic frequency for the early fault detection of the bearing. In this paper, a novel approach based on morphological operators is presented for impulsive signal extraction of early fault in rolling element bearing. The combination Top-Hat (CTH) is proposed to extract the impulsive signal and enhance the impulsiveness of the bearing fault signal, and the envelope analysis is applied to reveal the fault-related signatures. The impulsive extraction performance of the proposed CTH is compared with that of finite impulse response filter (FIR) by analyzing the simulated bearing fault signals, and the result indicates that the CTH is more effective in extracting impulsive signals. The method is evaluated using real fault signals from defective bearings with early rolling element fault and early fault located on the outer race. The results show that the proposed method is able to enhance the impulsiveness of early bearing fault signals.

Fault diagnosis of rolling element bearing compound faults based on sparse no-negative matrix factorization-support vector data description

2016 ◽  
Vol 24 (2) ◽  
pp. 272-282 ◽  
Author(s):  
Hongchao Wang
Keyword(s):  
Fault Diagnosis ◽  
Matrix Factorization ◽  
Rolling Element Bearing ◽  
Support Vector ◽  
Support Vector Data Description ◽  
Vector Data ◽  
Outer Race ◽  
Rolling Element ◽  
Sparse Coefficient ◽  
Element Bearing

The bispectrum of rolling element bearing compound faults contains abundant fault characteristic information, and how to extract the fault feature effectively is a key problem. The fault diagnosis method of rolling element bearing compound faults based on Sparse No-Negative Matrix Factorization (SNMF)-Support Vector Data Description (SVDD) is proposed in the paper. The figure handling method SNMF is used firstly in fault feature extraction of the bispectrums of rolling element bearing different kinds of compound faults and the sparse coefficient matrices of the bispectrums are obtained. The sparse coefficient matrices are used as training and test input vectors of SVDD. At last, the three kinds of rolling element bearing compound faults (inner race outer race compound faults, outer race rolling element compound faults and inner race outer race rolling element compound faults) are classified correctly. In order to verify the advantages of the proposed method, the diagnosis results of the same three kinds of rolling element bearing compound faults based on No-Negative Matrix Factorization (NMF)-SVDD is used as comparison. The proposed method provides a new idea for fault diagnosis of rolling element bearing compound faults.

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