Dynamics of Rolling Element—Bearings Experimental Validation of the DREB and RAPIDREB Computer Programs

1985 ◽  
Vol 107 (1) ◽  
pp. 132-137 ◽  
Author(s):  
P. K. Gupta ◽  
J. F. Dill ◽  
H. E. Bandow
Keyword(s):  
Experimental Data ◽  
Experimental Validation ◽  
Ball Bearing ◽  
Rolling Element Bearings ◽  
Mass Center ◽  
Angular Contact Ball Bearing ◽  
High Speeds ◽  
Rolling Element ◽  
General Motion ◽  
Good Agreement

The general motion of the cage predicted by the computer models in an angular contact ball bearing operating up to two million DN is compared against experimental data. Both the computer predictions and experimental data indicate a certain critical shaft speed at which the cage mass center begins to whirl. The predicted and measured whirl velocities and orbit shapes are in good agreement. The axial and radial velocities of the cage mass center also agree within the tolerance band of the expected experimental error. Due to experimental difficulties the cage angular velocity could not be reliabily measured at high speeds. At low speeds, however, there is a fair agreement between the experimental data and the analytical predictions.

Dynamics of Rolling-Element Bearings—Part IV: Ball Bearing Results

1979 ◽  
Vol 101 (3) ◽  
pp. 319-326 ◽  
Author(s):  
P. K. Gupta
Keyword(s):  
Differential Equations ◽  
Axial Load ◽  
Ball Bearing ◽  
Equations Of Motion ◽  
Rolling Element Bearings ◽  
Dynamic Simulations ◽  
Rolling Element ◽  
Overall Stability ◽  
The Stability ◽  
General Motion

Dynamic simulations of the performance of a ball bearing are presented in terms of the general motion as obtained by integrating the differential equations of motion of the various bearing elements. It is shown that bearing misalignment significantly influences the ball/cage and race/cage interaction and, hence, the stability of cage motion. The increased radial to axial load ratios promote skidding which couples with the lubricant behavior to impose accelerations on the ball which ultimately influence the ball/cage interactions. Hence, the lubricant behavior and the large load variation on the balls play dominant roles not only in determining the extent of skidding but also in establishing the overall stability of the cage motion.

Some Effects of Lubricant Composition and Tappet Rotation on Cam/Tappet Friction

1989 ◽  
Vol 111 (4) ◽  
pp. 683-691 ◽  
Author(s):  
P. A. Willermet ◽  
J. Pieprzak
Keyword(s):  
Experimental Data ◽  
Frictional Contact ◽  
Angular Resolution ◽  
Friction Model ◽  
Journal Bearings ◽  
Valve Train ◽  
Wave Form ◽  
Rolling Element Bearings ◽  
Lubricant Composition ◽  
Rolling Element

A cam/tappet friction rig was constructed from a 1.6 L Ford valve train. The head casting and the camshaft were shortened so that only two journal bearings remained. Only one of the two remaining cam/tappet contacts was used as a frictional contact. All other contacts were equipped with rolling element bearings so that essentially all the turning torque came from cam/tappet friction and valve spring forces. The rig, together with a data acquisition/wave form analyzer system and a computer, was capable of measuring instantaneous torque with an angular resolution of less than one degree, and reducing the data to provide calculated values for parameters such as the friction coefficient. The experimental data were compared with results from a cam/tappet friction model to assist in interpretation. The data and model illustrated that lubricant composition and tappet rotation have important effects not only on overall friction, but also on the shape of friction versus cam angle curves.

scholarly journals Influence of raceway waviness on the level of vibration in rolling-element bearings

2017 ◽  
Vol 65 (4) ◽  
pp. 541-551 ◽  
Author(s):  
S. Adamczak ◽  
P. Zmarzły
Keyword(s):  
Ball Bearing ◽  
Correlation Coefficients ◽  
Rolling Element Bearings ◽  
Test Results ◽  
Frequency Bandwidth ◽  
Surface Waviness ◽  
Medium Frequency ◽  
Method Of Calculation ◽  
Rolling Element ◽  
Bearing Vibration

AbstractThis paper provides a quantitative analysis of how raceway waviness (RONt) in 6304-type bearings affects their vibration. The waviness of bearing races was measured at the actual points of contact between the balls and the races. The measurements were conducted in the range of 16–50 undulations per revolution (UPR). The bearing vibration was analyzed in three bandwidths of frequency: low (LB) (50 ÷ 300 Hz), medium MB (300 ÷ 1800 Hz) and high HB (1800 ÷ 10 000 Hz), as well as in the full RMS bandwidth. The paper also presents the procedure used to determine the actual points of contact between the ball and each race to specify the point of waviness measurement. The method of calculation of the contact angle for a ball bearing is also discussed. The Pearson linear correlation coefficients were determined to analyze the relationships between the waviness parameters and the level of vibration. The test results show that an increase in the surface waviness on the inner and outer raceways causes an increase in the vibration level. The influence is most visible for the medium frequency bandwidth.

Dynamics of Rolling-Element Bearings—Part II: Cylindrical Roller Bearing Results

1979 ◽  
Vol 101 (3) ◽  
pp. 305-311 ◽  
Author(s):  
P. K. Gupta
Keyword(s):  
Differential Equations ◽  
Power Loss ◽  
Equations Of Motion ◽  
Roller Bearing ◽  
Geometrical Parameters ◽  
Rolling Element Bearings ◽  
Rolling Element ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller ◽  
General Motion

Cylindrical roller bearing performance simulations are expressed in terms of the general motion of the bearing elements as derived by integrating the differential equations of motion. Roller skew as induced by relative race misalignment is simulated. It is shown that skidding can be reduced by using a lubricant providing relatively high traction. However, such a fluid results in increased bearing torque and power loss. The influence of geometrical parameters, such as roller/cage, or race/cage clearance and radial preload, on the roller and cage motion is also investigated.

scholarly journals Demodulation of Vibration Signal Based on Envelope-Kurtogram for Ball Bearing Fault Detection

2020 ◽  
Vol 4 (2) ◽  
pp. 115-123
Author(s):  
Berli Paripurna Kamiel
Keyword(s):  
Ball Bearing ◽  
Vibration Signal ◽  
Rolling Element Bearings ◽  
Central Frequency ◽  
Value Analysis ◽  
Bearing Fault ◽  
Bearing Defect ◽  
Rolling Element ◽  
Signal Demodulation ◽  
Envelope Spectrum

Rolling element bearings often suffer damage due to harsh operating and environmental conditions. The method commonly used in detecting faults in a bearing is envelope analysis. However, this method requires setting the central frequency and the correct bandwidth - which corresponds to the resonance frequency of the bearing - for signal demodulation to be effective. This study proposes a kurtogram to determine the correct central frequency and bandwidth to obtain the frequency band with the highest impulse content or the highest kurtosis value. Analysis envelope is applied to the filtered vibration signal using the central frequency and bandwidth parameters obtained from the kurtogram. The results showed that the envelope-kurtogram method is effective for faulty bearing detection as shown in the envelope spectrum where the peaks coincide with the bearing defect characteristic frequency (BPFO) with high accuracy. Likewise, it can be observed several BPFO harmonics which provide information on the level of bearing fault.

Lubrication Analysis of a Rolling Piston Rotary Compressor: Part 2: Experimental Validation and Results

1994 ◽  
Vol 208 (2) ◽  
pp. 95-104
Author(s):  
S K Padhy
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Experimental Validation ◽  
Sensitivity Study ◽  
Rotary Compressor ◽  
Oil Flow ◽  
Different Dimensions ◽  
Rolling Piston ◽  
The Mathematical Model ◽  
Good Agreement

In this paper the experiments conducted for the measurement of oil flow in the rotary compressor are described. The experimental data are compared against the theoretical prediction from the mathematical model developed (1) and a good agreement is found. In addition, experimental data from previously published literature are also used to verify the mathematical model. A sensitivity study is carried out to predict the behaviour of the rotary compressor for the oil flow at different conditions and with different dimensions.

Experimental and Computational Study of Effects of Viscosity of the Filter Media in a Developed Particulate Trapping System

2018 ◽  
Vol 9 (5) ◽  
Author(s):  
Y. Liu
Keyword(s):  
Experimental Data ◽  
Management System ◽  
Experimental Validation ◽  
Computational Study ◽  
Cost Effective ◽  
Manufacturing Cost ◽  
Present System ◽  
Computational Results ◽  
Experimental Assessment ◽  
Good Agreement

A cost effective, portable particulate management system was developed, prototyped, and evaluated for further application and commercialization, which could remove and dispose particulate matter suspended in air efficiently and safely. A prototype of the present system was built for experimental assessment and validation. The experimental data showed that the developed particulate management system can effectively clean the air by capturing the particles inside it. Effects of viscosity of filter medium on the performance of the developed system were also discussed. The present system is very flexible, whose size and shape can be scaled and changed to be fit for different applications. Its manufacturing cost is less than $10. Based on the experimental validation results, it was found that the present system can be further developed, commercialized, and applied for a variety of industries. The experiments and experimental data were simulated and validated using computer fluent dynamics. A relatively good agreement was achieved between the experimental and computational results.

Theory of High-Speed Displacement Ships with Transom Sterns

1986 ◽  
Vol 30 (03) ◽  
pp. 186-193
Author(s):  
Marshall P. Tulin ◽  
C. C. Hsu
Keyword(s):  
Experimental Data ◽  
High Speed ◽  
Parametric Form ◽  
High Speeds ◽  
New Finding ◽  
Good Agreement

A theory has been developed for high-speed displacement ships with transom sterns; it treats the hull as finite in beam and draft, but slender. The flow is assumed to be smooth at the aft waterline and to have a trailing wake. The trailing wake results in substantial residuary resistance at high speeds for normal waterline ships. This is a completely new finding. Calculations are made for ships of highly variable parametric form and the results are given. This residuary is typically reduced by widening the transom. A shallow draft at the transom is also indicated. A comparison of calculated results with existing experimental data shows good agreement.

Ball Bearing Response to Cage Unbalance

1986 ◽  
Vol 108 (3) ◽  
pp. 462-466 ◽  
Author(s):  
P. K. Gupta ◽  
J. F. Dill ◽  
J. W. Artuso ◽  
N. H. Forster
Keyword(s):  
Entire Range ◽  
High Speed ◽  
Ball Bearing ◽  
Operating Conditions ◽  
Angular Contact Ball Bearing ◽  
Turbine Engine ◽  
Wide Range ◽  
Inner Race ◽  
Good Agreement ◽  
Engine Bearing

Motion of the cage in a high-speed angular contact ball bearing is experimentally investigated as a function of prescribed unbalance, up to operating speeds corresponding to three million DN. The predictions of cage motion made by the recently developed computer model, ADORE, are validated in the light of the experimental data. It is shown the cage whirl velocity is essentially equal to its angular velocity at all levels of unbalance and over a wide range of operating conditions. For the inner race guided turbine engine bearing, the cage/race interaction takes place directly opposite to the location of the unbalance and the severity of the interaction increases with the level of unbalance and the operating speed. ADORE predictions, over the entire range of unbalance and bearing operating conditions, are in very good agreement with the experimental observations.

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