Some Thermal Implications on the Life of High Speed Rolling Element Bearings

1988 ◽  
pp. 147-151
Author(s):  
Richard Nicholson
Keyword(s):  
High Speed ◽  
Rolling Element Bearings ◽  
Rolling Element

scholarly journals Commissioning of a High Speed Composite Rotor With Hydrostatic Dampers and Ceramic Rolling Element Bearings

1993 ◽  
Author(s):  
Ross N. Headifen ◽  
Robert L. Fuller ◽  
Jon R. Kitzmiller
Keyword(s):  
High Speed ◽  
System Analysis ◽  
Rolling Element Bearings ◽  
Lumped Mass ◽  
One Dimensional ◽  
System A ◽  
Rolling Element ◽  
Speed Range ◽  
Full Speed ◽  
Stiffness And Damping

Abstract A high speed (25,000 rpm) routing machine with a 300 lb rotor was designed and manufactured. To accommodate the high shaft speed, 2.6 million DN, rolling element bearings were used with ceramic balls and inner races. In order to control the magnitude of the vibration, damping was incorporated into the system using nonrotating hydrostatic dampers. The journal for the dampers was a cylindrical cartridge that had the rolling element bearings clamped inside of it. Extensive analysis was performed on this system. A computer program was written that could model the orbit path of the lumped mass shaft in the damper over the full speed range. A second program was also written that calculated the damper nonlinear stiffness and damping coefficients, and incorporated them in with a one-dimensional beam, finite element rotordynamics model of the system. Analysis results are presented along with experimental run data from the machine. Balancing problems encountered during commissioning have limited the results to 16,500 rpm to date. The last of which is currently being remedied.

Vibration Monitoring and Damage Quantification of Faulty Ball Bearings

2005 ◽  
Vol 127 (4) ◽  
pp. 776-783 ◽  
Author(s):  
F. K. Choy ◽  
J. Zhou ◽  
M. J. Braun ◽  
L. Wang
Keyword(s):  
High Speed ◽  
Progressive Failure ◽  
Frequency Domain Analysis ◽  
Vibration Monitoring ◽  
Ball Bearings ◽  
Rolling Element Bearings ◽  
Premature Failure ◽  
Damage And Failure ◽  
Rolling Element ◽  
Safety And Reliability

More often than not, the rolling element bearings in rotating machinery are the mechanical components that are first prone to premature failure. Early warning of an impending bearing failure is vital to the safety and reliability of high-speed turbomachinery. Presently, vibration monitoring is one of the most applied procedures in on-line damage and failure monitoring of rolling element bearings. This paper presents results from an experimental rotor-bearing test rig with quantified damage induced in the supporting rolling element bearings. Both good and damaged radial and tapered ball bearings are used in this study. The vibration signatures due to damage at the ball elements and the inner race of the bearing are also examined. Vibration signature analyzing schemes such as frequency domain analysis, and chaotic vibration analysis (modified Poincare diagrams) are applied and their effectiveness in pinpoint damage are compared in this study. The size/level of the damage is corroborated with the vibration amplitudes to provide quantification criteria for bearing progressive failure prediction. Based on the results from this study, it is shown that the use of the modified Poincare map, based on the relative carrier speed, can provide an effective way for identification and quantification of bearing damage in rolling element bearings.

Rotor Dynamics in Design of a High Speed Cryogenic Pump for Geo Stationary Launch Vehicles

2014 ◽  
Author(s):  
Srinivasa R. Jammi
Keyword(s):  
High Speed ◽  
Rotor Dynamics ◽  
Rotor System ◽  
Peak Amplitude ◽  
Beam Model ◽  
Rolling Element Bearings ◽  
Launch Vehicles ◽  
Critical Speeds ◽  
Highly Nonlinear ◽  
Rolling Element

On January 5th 2014 the Indian Space Research Organization successfully launched its Geo Stationary Launch Vehicle with an indigenous Cryogenic engine. One of the main design aspects is in its rotor dynamics to predict the peak amplitude unbalance whirl and the speed at which it occurs. This engine has several key technologies, one of them specifically is coupled rotors, viz., Turbine, Hydrogen Pump and Oxidizer supported on seven nonlinear rolling element bearings and several seals all mounted in a flexible casing. The conventional beam model initially adopted failed to predict the speed at which peak unbalance response occurs. The rotor system was first developed in a solid model to determine the critical speeds of the rotor alone considering its 40000 rpm centrifugal loads with bearings treated as linear. Then, unbalance whirl of this rotor system was developed by codes specially developed for this purpose. The rolling element bearings are found to be highly nonlinear with large bearing radial forces at critical speeds. An iterative procedure was developed to match the bearing force and unbalance whirl to determine peak amplitude response speeds. Subsequently, seals and the influence of casing and internal pressures were accounted in the analysis. This paper describes the advanced rotor dynamic design of this pump.

Fault Diagnosis of High Speed Rolling Element Bearings Due to Localized Defects Using Response Surface Method

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
P. K. Kankar ◽  
Satish C. Sharma ◽  
S. P. Harsha
Keyword(s):  
Fault Diagnosis ◽  
Response Surface ◽  
Response Surface Method ◽  
High Speed ◽  
Mathematical Formulation ◽  
Rolling Element Bearings ◽  
Surface Method ◽  
Rolling Element ◽  
Rolling Elements ◽  
Localized Defects

In this paper, fault diagnosis of high speed rolling element bearings due to localized defects using response surface method has been done. The localized defects as spalls on outer race, on inner race, and on rolling elements are considered for this study. The mathematical formulation accounted for tangential motions of rolling elements and inner and outer races with the sources of nonlinearity such as Hertzian contact force and internal radial clearance. The nonlinear stiffness is obtained by the application of Hertzian elastic contact deformation theory. The mathematical formulation predicts discrete spectrum having peaks at the characteristic defect frequencies and their harmonics. Experimentation has also been performed to validate the results obtained from the mathematical model and it shows that the model can be successfully used to predict amplitude ratios among various spectral lines with localized surface defects. Combined parametric effects have been analyzed and their influence has been considered with design of experiments and surface response methodology is used to predict the dynamic response of a rotor bearing system.

scholarly journals The Hybrid KICA-GDA-LSSVM Method Research on Rolling Bearing Fault Feature Extraction and Classification

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jiyong Li ◽  
Shunming Li ◽  
Xiaohong Chen ◽  
Lili Wang
Keyword(s):  
Feature Extraction ◽  
High Speed ◽  
Wavelet Packet ◽  
Rolling Bearing ◽  
Least Square ◽  
Support Vector ◽  
Rolling Element Bearings ◽  
Kernel Independent Component Analysis ◽  
Rolling Element ◽  
Independent Features

Rolling element bearings are widely used in high-speed rotating machinery; thus proper monitoring and fault diagnosis procedure to avoid major machine failures is necessary. As feature extraction and classification based on vibration signals are important in condition monitoring technique, and superfluous features may degrade the classification performance, it is needed to extract independent features, so LSSVM (least square support vector machine) based on hybrid KICA-GDA (kernel independent component analysis-generalized discriminate analysis) is presented in this study. A new method named sensitive subband feature set design (SSFD) based on wavelet packet is also presented; using proposed variance differential spectrum method, the sensitive subbands are selected. Firstly, independent features are obtained by KICA; the feature redundancy is reduced. Secondly, feature dimension is reduced by GDA. Finally, the projected feature is classified by LSSVM. The whole paper aims to classify the feature vectors extracted from the time series and magnitude of spectral analysis and to discriminate the state of the rolling element bearings by virtue of multiclass LSSVM. Experimental results from two different fault-seeded bearing tests show good performance of the proposed method.

The Error Caused by Order Analysis for Rolling Bearing Fault Signal

2013 ◽  
Vol 819 ◽  
pp. 254-258 ◽  
Author(s):  
Wei Dong Cheng ◽  
Robert X. Gao ◽  
Jin Jiang Wang ◽  
Tian Yang Wang ◽  
Wei Gang Wen ◽  
...  
Keyword(s):  
High Speed ◽  
Vibration Signal ◽  
Rolling Bearing ◽  
Rate Of Change ◽  
Rolling Element Bearings ◽  
Factors Affecting ◽  
Order Analysis ◽  
Rolling Element ◽  
Angular Interval ◽  
The Time Domain

Defect diagnosis of rolling element bearings operating under time-varying rotational speeds entails order tracking and analysis techniques that convert a vibration signal from the time domain to the angle domain to eliminate the effect of speed variations. When a signal is resampled at a constant angular increment, the amount of data padded into each data segment will vary, depending on the rate of change in the rotational speeds. This leads to changes in the distance between the adjacent impulse peaks, and consequently, the result of order analysis. This paper presents a quantitative analysis of key factors affecting the accuracy of order analysis on rolling element bearings under variable speeds. An analytical model is established and simulated. The effects of speed variation, instantaneous speed, angular interval between impulses, and the rising time of impulse are specified. It is concluded that the results of order analysis will be smaller as the rotational speed increases, and becomes larger when the speed decreases. Furthermore, the error is larger under low speeds than high speed.

scholarly journals An Assessment of Gas Foil Bearing Scalability and the Potential Benefits to Civilian Turbofan Engines

2010 ◽  
Author(s):  
Robert J. Bruckner
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Advanced Technology ◽  
Rolling Element Bearings ◽  
Turbofan Engines ◽  
Foil Bearings ◽  
Foil Bearing ◽  
Fuel Burn ◽  
Rolling Element ◽  
Rotor Support

Over the past several years the term oil-free turbomachinery has been used to describe a rotor support system for high speed turbomachinery that does not require oil for lubrication, damping, or cooling. The foundation technology for oil-free turbomachinery is the compliant foil bearing. This technology can replace the conventional rolling element bearings found in current engines. Two major benefits are realized with this technology. The primary benefit is the elimination of the oil lubrication system, accessory gearbox, tower shaft, and one turbine frame. These components account for 8–13% of the turbofan engine weight. The second benefit that compliant foil bearings offer to turbofan engines is the capability to operate at higher rotational speeds and shaft diameters. While traditional rolling element bearings have diminished life, reliability, and load capacity with increasing speeds, the foil bearing has a load capacity proportional to speed. The traditional applications for foil bearings have been in small, lightweight machines. However, recent advancements in the design and manufacturing of foil bearings have increased their potential size. An analysis, grounded in experimentally proven operation, is performed to assess the scalability of the modern foil bearing. This analysis coupled to the requirements of civilian turbofan engines. The application of the foil bearing to larger, high bypass ratio engines nominally at the 120 kN (∼25000 pound) thrust class has been examined. The application of this advanced technology to this system was found to reduce mission fuel burn by 3.05%.

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