Dynamics of Bearing Shaft Systems

2005 ◽  
Author(s):  
Farshid Sadeghi ◽  
Carl Wassgren ◽  
Nicholas Prenger ◽  
Niranjan Ghaisas ◽  
Eric Chamberlain
Keyword(s):  
Rolling Bearing ◽  
Rolling Element Bearings ◽  
Loading Conditions ◽  
Rotating Shaft ◽  
Type Analysis ◽  
Rolling Element ◽  
Rolling Elements ◽  
Bearing Dynamics ◽  
Bearing System

The objective of this study was to develop a bearing model which can be combined with shafts, gears etc. to virtually investigate the motion and loading of the elements in the bearing. Models for ball, cylindrical and tapered rolling bearing dynamics have been designed, developed and combined with rigid and flexible shafts subject to various loading conditions and eccentric masses. The results from this investigation demonstrated that for rotating shaft bearing systems, the motion and the loads on the rolling elements are significantly different than that predicted by static and / or quasi-static type analysis. Results from shaft bearing system, where shaft may be supported by combinations of ball and rolling element bearings will be demonstrated. Cage motion and stability under various load and speed combinations will be discussed.

Multibody Rolling Bearing Calculations: Computer Program BEAST

2005 ◽  
Author(s):  
E. Ioannides ◽  
L.-E. Stacke ◽  
D. Fritzson ◽  
I. Nakhimovski
Keyword(s):  
Computer Program ◽  
High Efficiency ◽  
Rapid Development ◽  
Rolling Bearing ◽  
Rolling Element Bearings ◽  
Jet Engines ◽  
Simulation Tools ◽  
Rolling Element ◽  
Rolling Elements ◽  
Multi Body

The need for rapid development of high efficiency jet engines and other mechanical systems has forced the pace of development of simulation tools so that the detailed behavior of the rolling element bearings can be simulated. This includes modeling of the motions, the exchanged forces, and heat between all the bearing components, i.e. rings, cage and rolling elements. The computer program BEAST is a multi-body computer program with sophisticated and robust modeling of the tribological contacts in the bearing where the exchange of forces between the bearing components takes place.

Vibration model of rolling element bearings in a rotor-bearing system for fault diagnosis

2013 ◽  
Vol 332 (8) ◽  
pp. 2081-2097 ◽  
Author(s):  
Feiyun Cong ◽  
Jin Chen ◽  
Guangming Dong ◽  
Michael Pecht
Keyword(s):  
Fault Diagnosis ◽  
Rolling Element Bearings ◽  
Vibration Model ◽  
Rolling Element ◽  
Rotor Bearing ◽  
Bearing System

Nonlinear Modeling of a Rigid Rotor Supported on Rolling Element Bearings With Localized Defects

2010 ◽  
Author(s):  
Karthik Kappaganthu ◽  
C. Nataraj
Keyword(s):  
Nonlinear Model ◽  
Nonlinear Models ◽  
Nonlinear Modeling ◽  
Rolling Element Bearings ◽  
Rigid Rotor ◽  
Rolling Element ◽  
Localized Defects ◽  
Bearing Race ◽  
Overall Performance ◽  
Bearing System

In this paper a nonlinear model for defects in rolling element bearings is developed. Detailed nonlinear models are useful to detect, estimate and predict failure in rotating machines. Also, accurate modeling of the defect provides parameters that can be estimated to determine the health of the machine. In this paper the rotor-bearing system is modeled as a rigid rotor and the defects are modeled as pits in the bearing race. Unlike the previous models, the motion of the rolling element thorough the defect is not modeled as a predetermined function; instead, it is dynamically determined since it depends on the clearance and the position of the shaft. Using this nonlinear model, the motion of the shaft is simulated and the effect of the rolling element passing through the defect is studied. The effect of shaft parameters and the defect parameters on the precision of the shaft and the overall performance of the system is studied. Finally, suitable measures for health monitoring and defect tracking are suggested.

The Monitoring of the Bearing Nodes with Excessive Radial Clearances Using the FAM-C and FDM-A Methods

2009 ◽  
Vol 25 (1) ◽  
pp. 109-127 ◽  
Author(s):  
Andrzej Gębura ◽  
Tomasz Tokarski
Keyword(s):  
Resonant State ◽  
Lubricant Film ◽  
Rolling Element Bearings ◽  
Mechanical Verification ◽  
Macro Scale ◽  
Rolling Element ◽  
Rolling Elements ◽  
Diagnostic Work ◽  
Theoretical Analyses

The Monitoring of the Bearing Nodes with Excessive Radial Clearances Using the FAM-C and FDM-A Methods The paper has been intended to present findings resulting from the monitoring of the bearing support elements with increased radial clearances with the FAM-C1 and FDM-A2 methods. The role the lubricant film plays in this type of the rolling-elements' wear has been described. Discussed are symptoms, parameters, and hazards to the resonant state in bearing nodes, as well as capabilities of diagnosing them with the FAM-C and FDM-A methods. Hypotheses about subsequent stages of the wearing process in aircraft turbojet engine's bearing support assemblies, including how the resonant state occurs, have been presented. The mechanism of the resonance in rolling-element bearings has been described, with particular attention paid to the effects of gyrostatic moments upon the bearing support elements, both in micro- and macro-scale. Theoretical analyses have been supplemented with findings resulting from the diagnostic work carried out by the Authors, and with data from the mechanical verification of engines in the course of the authorised dismantling thereof.

Dynamic Interactions Between the Rolling Element and the Cage in Rolling Bearing Under Rotational Speed Fluctuation Conditions

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Wenbing Tu ◽  
Ya Luo ◽  
Wennian Yu
Keyword(s):  
Dynamic Model ◽  
Rotational Speed ◽  
Rolling Bearing ◽  
Nonlinear Dynamic Model ◽  
Dynamic Interactions ◽  
Interaction Forces ◽  
Rolling Element ◽  
Speed Fluctuation ◽  
Rolling Elements ◽  
Fluctuation Frequency

Abstract A nonlinear dynamic model is proposed to investigate the dynamic interactions between the rolling element and cage under rotational speed fluctuation conditions. Discontinuous Hertz contact between the rolling element and the cage and lubrication and interactions between rolling elements and raceways are considered. The dynamic model is verified by comparing simulation result with the published experimental data. Based on this model, the interaction forces and the contact positions between the rolling element and the cage with and without the rotational speed fluctuation are analyzed. The effects of fluctuation amplitude, fluctuation frequency, and cage pocket clearance on the interaction forces between the rolling element and the cage are also investigated. The results show that the fluctuation of the rotational speed and the cage pocket clearance significantly affects the interaction forces between the rolling element and the cage.

Ceramics in Rolling Element Bearings

1979 ◽  
Author(s):  
C. F. Bersch ◽  
Philip Weinberg
Keyword(s):  
Fatigue Life ◽  
Silicon Nitride ◽  
Cooling System ◽  
Extreme Environment ◽  
Ball Bearings ◽  
Rolling Element Bearings ◽  
Turbine Engine ◽  
Rolling Element ◽  
Rolling Elements ◽  
History Of

The feasibility of using hot-pressed silicon nitride (HPSN) for rolling elements and for races in ball bearings and roller bearings has been explored. HPSN offers opportunities to alleviate many current bearing problems including DN and fatigue life limitations, lubricant and cooling system deficiencies, and extreme environment demands. The history of ceramic bearings and the results of various element tests, bearing tests in rigs, and bearing tests in a turbine engine will be reviewed. The advantages and problems associated with the use of HPSN in rolling element bearings will be discussed.

scholarly journals Component Hardness Differences and Their Effect on Bearing Fatigue

1967 ◽  
Vol 89 (1) ◽  
pp. 47-54 ◽  
Author(s):  
E. V. Zaretsky ◽  
R. J. Parker ◽  
W. J. Anderson
Keyword(s):  
Fatigue Life ◽  
Residual Stresses ◽  
Load Capacity ◽  
Full Scale ◽  
Contact Temperature ◽  
Rolling Element Bearings ◽  
Rolling Element ◽  
Rolling Elements ◽  
Compressive Residual Stresses

The five-ball fatigue tester and full-scale rolling-element bearings were used to determine the effect of component hardness differences of SAE 52100 steel on bearing fatigue and load capacity. Maximum fatigue life and load capacity are achieved when the rolling elements of a bearing are one to two points (Rockwell C) harder than the races. There appears to be an interrelation among compressive residual stresses induced in the races during operation, differences in component hardness, and fatigue life. Differences in contact temperature and plastically deformed profile radii could not account for differences in fatigue life.

Diagnosis of Rolling-Element Bearings Failure by Localized Electrical Current Between Track Surfaces of Races and Rolling-Elements

2002 ◽  
Vol 124 (3) ◽  
pp. 468-473 ◽  
Author(s):  
Har Prashad
Keyword(s):  
Theoretical Model ◽  
Electrical Current ◽  
Rolling Element Bearing ◽  
Rolling Element Bearings ◽  
Bearing Failure ◽  
Cause Analysis ◽  
Rolling Element ◽  
Rolling Elements ◽  
Dimensional Parameters ◽  
Element Bearing

The diagnosis and cause analysis of rolling-element bearing failure have been well studied and established in literature. Failure of bearings due to unforeseen causes were reported as: puncturing of bearings insulation; grease deterioration; grease pipe contacting the motor base frame; unshielded instrumentation cable; the bearing operating under the influence of magnetic flux, etc. These causes lead to the passage of electric current through the bearings of motors and alternators and deteriorate them in due course. But, bearing failure due to localized electrical current between track surfaces of races and rolling-elements has not been hitherto diagnosed and analyzed. This paper reports the cause of generation of localized current in presence of shaft voltage. Also, it brings out the developed theoretical model to determine the value of localized current density depending on dimensional parameters, shaft voltage, contact resistance, frequency of rotation of shaft and rolling-elements of a bearing. Furthermore, failure caused by flow of localized current has been experimentally investigated.

Rolling bearing damping for dynamic analysis of multi-body systems—experimental and theoretical results

2000 ◽  
Vol 214 (1) ◽  
pp. 33-43 ◽  
Author(s):  
P Dietl ◽  
J Wensing ◽  
G C van Nijen
Keyword(s):  
Hydrodynamic Lubrication ◽  
Rolling Bearing ◽  
Classical Approach ◽  
Lubricated Contacts ◽  
Rolling Element ◽  
Rolling Elements ◽  
Experimental Approaches ◽  
Multi Body ◽  
Damping Model ◽  
Damping Capability

The present paper deals with the measurement and calculation of the damping capability of rolling element bearings. Rolling bearing damping is strongly influenced by the lubricated contacts between rolling elements and raceways. A theoretical model for calculating lubricant film (elasto-hydrodynamic lubrication) damping is briefly described in the first part of this paper. Furthermore, a relationship for estimating damping due to other dissipative mechanisms in the bearing is suggested. In the second part, two experimental approaches for measuring rolling bearing damping are discussed. The first (more ‘classical’) approach is based on conventional frequency response measurements and was used to verify the developed damping model regarding the influence of bearing lubrication, speed and preload. Finally, a new experimental approach for identifying rolling bearing damping is presented, eliminating some of the drawbacks of the ‘classical’ approach.

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