The Importance of Spinning Friction in Thrust-Carrying Ball Bearings

1960 ◽  
Vol 82 (2) ◽  
pp. 295-300 ◽  
Author(s):  
G. S. Reichenbach
Keyword(s):  
Contact Angle ◽  
Experimental Work ◽  
Major Part ◽  
Ball Bearing ◽  
Thrust Bearing ◽  
Contact Angles ◽  
Ball Bearings ◽  
Flat Plates ◽  
Theoretical Predictions ◽  
Rolling Balls

Experimental work was done rolling balls on flat plates and in V-grooves at loads and contact angles corresponding to usual thrust-bearing practice. It is shown that the spinning action of the ball with respect to the race should account for the major part of the over-all friction of a thrust-carrying ball bearing. Variables studied included contact angle, conformity, load, lubricant, and temperature. The results have been correlated and shown to follow theoretical predictions.

Prediction of Ball Motion in High-Speed Thrust-Loaded Ball Bearings

1976 ◽  
Vol 98 (3) ◽  
pp. 463-469 ◽  
Author(s):  
C. R. Gentle ◽  
R. J. Boness
Keyword(s):  
Computer Program ◽  
High Speed ◽  
Ball Bearing ◽  
Viscoelastic Behavior ◽  
Specific Situation ◽  
Fluid Models ◽  
Ball Bearings ◽  
Theoretical Predictions ◽  
Ball Motion

This paper describes the development of a computer program used to analyze completely the motion of a ball in a high-speed, thrust-loaded ball bearing. Particular emphasis is paid to the role of the lubricant in governing the forces and moments acting on each ball. Expressions for these forces due to the rolling and sliding of the ball are derived in the light of the latest fluid models, and estimates are also made of the cage forces applicable in this specific situation. It is found that only when lubricant viscoelastic behavior is considered do the theoretical predictions agree with existing experimental evidence.

Experimental Routes to Chaos in Ball Bearings

2007 ◽  
Author(s):  
B. Mevel ◽  
J. L. Guyader
Keyword(s):  
Theoretical Prediction ◽  
Resonant Frequency ◽  
Experimental Test ◽  
Test Bench ◽  
Ball Bearing ◽  
Ball Bearings ◽  
Poincaré Maps ◽  
Routes To Chaos ◽  
Theoretical Predictions ◽  
Experimental Test Bench

In a previous paper [1], the theoretical prediction of a ball bearing motion was studied and different routes to chaos described. The aim of this paper is to study experimentally routes to chaos in a ball bearing and to observe whether theoretical predictions of the phenomena are realistic. An experimental test bench was built and a technique to observe Poincare´ maps is proposed. The experience clearly shows the appearance of instability in the bearing motion, and two different routes to chaos are described as expected in theory. The first route is related to the first resonant frequency of the bearing. It is a sub-harmonic route. The second route, related to the second resonant frequency, is a quasi-periodic route.

3D Simplified Finite Elements Analysis of Load and Contact Angle in a Slewing Ball Bearing

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Alain Daidié ◽  
Zouhair Chaib ◽  
Antoine Ghosn
Keyword(s):  
Contact Angle ◽  
Load Distribution ◽  
Ball Bearing ◽  
Numerical Models ◽  
Contact Angles ◽  
Calculation Model ◽  
Combined Loading ◽  
Finite Elements Analysis ◽  
Supporting Structure ◽  
Industrial Structures

Bolted bearing connections are one of the most important connections in some industrial structures, and manufacturers are always looking for a quick calculation model for a safe design. In this context, all the analytical and numerical models reduce the global study to the study of the most critical sector. Therefore, the main inputs for these models are the maximal equivalent contact load and the corresponding contact angle. Thus, a load distribution calculation model that takes all the important parameters, such as the stiffness of the supporting structure and the variation in the contact angle, into consideration is needed. This paper presents a 3D finite element (FE) simplified analysis of load distribution and contact angle variation in a slewing ball bearing. The key element of this methodology, which is based on the Hertz theory, is modeling the rolling elements under compression by nonlinear traction springs between the centers of curvature of the raceways. The contact zones are modeled by rigid shells to avoid numerical singularities. Each raceway curvature center is coupled to the corresponding contact zone by rigid shells. The main contribution of this method is not only the evaluation of the contact loads with a relatively reduced calculation time but also the variation in the contact angle from the deformed coordinates of the curvature centers. Results are presented for several loading cases: axial loading, turnover moment, and a combined loading of axial force and turnover moment. The influence of the most important parameters such as the contact angle, the stiffness of the bearings, and the supporting structure is discussed. Finally, a preliminary experimental validation is conducted on a standard ball bearing. The results presented in this paper seem encouraging. The FE study shows an important influence of several parameters and a good correlation with experimental results. Consequently, this model can be extended to other types of slewing bearings such as roller bearings. Moreover, it can be implemented in complex industrial structures such as cranes and lifting devices to determine the corresponding load distributions and contact angles and, consequently, the most critical sector.

Pitch bearing/raceway fretting: Influence of contact angle

2018 ◽  
Vol 233 (5) ◽  
pp. 1734-1749 ◽  
Author(s):  
Peiyu He ◽  
Rongjing Hong ◽  
Hua Wang ◽  
Cheng Lu
Keyword(s):  
Contact Angle ◽  
Maximum Stress ◽  
Ball Bearing ◽  
Three Dimensional ◽  
Contact Angles ◽  
Critical Parameters ◽  
Relative Slip ◽  
Contact State ◽  
Pitch Bearing ◽  
Bearing Raceway

In this paper, a three-dimensional numerical simulation (using ABAQUS) of the radial and tangential wear between a ball bearing and a raceway is presented. The aim was to study the influence of the contact angle between ball and raceway on the fretting. A range of contact angles was studied with critical parameters such as contact stress, relative slip, plastic deformation, and contact state. The model was validated against experimental data. The results show that with an increase in the contact angle, the area of maximum stress increases, the bearing capacity of the raceway decreases, and the maximum radial stress moves from the sub-surface to the raceway surface. The raceway surface is shown to be prone to peeling and wear, which reduces the service life of the raceway.

Investigation of Optimizing Arrangement Forms for Combined Angular Contact Ball Bearings

2017 ◽  
Author(s):  
Bin Fang ◽  
Jinhua Zhang ◽  
Jun Hong ◽  
Yongsheng Zhu ◽  
Xu Wang ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Contact Angle ◽  
Load Distribution ◽  
Contact Angles ◽  
Rotating Machinery ◽  
Initial Contact ◽  
Ball Bearings ◽  
Heavy Load ◽  
Initial Contact Angle ◽  
Machinery System

The combined angular contact bearings are widely used in numerous rotating machinery system, but few research works on the combined angular contact ball bearings have been reported. To solve the problem about inconsistency fatigue life of the bearings in the combined bearings with asymmetric arrangement, this paper proposed a special combined bearings arrangement form in which the bearings with different contact angles are used simultaneously for the bearing combination. In order to validate the effectiveness of the proposed method, a mathematical model is proposed to analyze the load distribution, life and stiffness of the combined bearings, and the combined bearings with three different arrangements are comparatively calculated and analyzed. The results show that the whole life of combined bearings is mainly depend on the life of the bearing under heavy load, and the new arrangement form in which the initial contact angle of the bearing under heavy load is increased that can improve the whole life of combined bearings.

scholarly journals Damage Risk of the Raceway Edge Arise in Four-Point Slewing Bearing

2019 ◽  
Vol 1 (1) ◽  
pp. 632-638
Author(s):  
Marek Krynke ◽  
Krzysztof Mielczarek
Keyword(s):  
Contact Angle ◽  
Ball Bearing ◽  
Point Contact ◽  
Contact Angles ◽  
Bearing Ring ◽  
Rolling Elements ◽  
Damage Risk ◽  
Slewing Bearings ◽  
Early Damage ◽  
Selection Of

AbstractIn the article some forms of damage to raceway of slewing bearings for single-row ball bearing slewing ring with four-point contact and their causes were shown. Changes of the contact angle and its influence on the geometry for contact zone of the rolling elements raceway were analyzed. An identification of changes for contact angle of individual balls for different parameters of the contact was received. It was showed that contact angles of some rolling elements were increasing. It can cause damage to the raceway by spalling or rolling out of edge of the bearing ring. Ways of avoiding too early damage to the raceway at the stage of the design and the selection of coronary bearings were suggested.

Vibration Forces Produced by Waviness of the Rolling Surfaces of Thrust Loaded Ball Bearings Part 2: Experimental Validation

1988 ◽  
Vol 202 (5) ◽  
pp. 313-319 ◽  
Author(s):  
F P Wardle
Keyword(s):  
Experimental Validation ◽  
Ball Bearing ◽  
Transfer Functions ◽  
Ball Bearings ◽  
Vibration Measurements ◽  
Theoretical Predictions ◽  
Theory And Experiment

Experimental vibration measurements of a system containing a single ball bearing are compared with theoretical predictions based upon the model described in Part 1 and measurements of system transfer functions. Agreement between theory and experiment is reasonable.

Temperature Rise Prediction of Oil-Air Lubricated Angular Contact Ball Bearings Using Artificial Neural Network

2019 ◽  
Vol 12 (3) ◽  
pp. 248-261
Author(s):  
Baomin Wang ◽  
Xiao Chang
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Temperature Rise ◽  
High Speed ◽  
Ball Bearing ◽  
Influence Factors ◽  
Ball Bearings ◽  
Ann Model ◽  
Angular Contact Ball Bearing ◽  
Artificial Neural

Background: Angular contact ball bearing is an important component of many high-speed rotating mechanical systems. Oil-air lubrication makes it possible for angular contact ball bearing to operate at high speed. So the lubrication state of angular contact ball bearing directly affects the performance of the mechanical systems. However, as bearing rotation speed increases, the temperature rise is still the dominant limiting factor for improving the performance and service life of angular contact ball bearings. Therefore, it is very necessary to predict the temperature rise of angular contact ball bearings lubricated with oil-air. Objective: The purpose of this study is to provide an overview of temperature calculation of bearing from many studies and patents, and propose a new prediction method for temperature rise of angular contact ball bearing. Methods: Based on the artificial neural network and genetic algorithm, a new prediction methodology for bearings temperature rise was proposed which capitalizes on the notion that the temperature rise of oil-air lubricated angular contact ball bearing is generally coupling. The influence factors of temperature rise in high-speed angular contact ball bearings were analyzed through grey relational analysis, and the key influence factors are determined. Combined with Genetic Algorithm (GA), the Artificial Neural Network (ANN) model based on these key influence factors was built up, two groups of experimental data were used to train and validate the ANN model. Results: Compared with the ANN model, the ANN-GA model has shorter training time, higher accuracy and better stability, the output of ANN-GA model shows a good agreement with the experimental data, above 92% of bearing temperature rise under varying conditions can be predicted using the ANNGA model. Conclusion: A new method was proposed to predict the temperature rise of oil-air lubricated angular contact ball bearings based on the artificial neural network and genetic algorithm. The results show that the prediction model has good accuracy, stability and robustness.

scholarly journals Influence of moisture content on the contact angle and surface tension measured on birch wood surfaces

2021 ◽  
Author(s):  
Rami Benkreif ◽  
Fatima Zohra Brahmia ◽  
Csilla Csiha
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Moisture Content ◽  
Solid Wood ◽  
Contact Angles ◽  
Surface Moisture ◽  
Wood Coatings ◽  
The Relationship ◽  
Wood Surfaces

AbstractSurface tension of solid wood surfaces affects the wettability and thus the adhesion of various adhesives and wood coatings. By measuring the contact angle of the wood, the surface tension can be calculated based on the Young-Dupré equation. Several publications have reported on contact angle measured with different test liquids, under different conditions. Results can only be compared if the test conditions are similar. While the roles of the drop volume, image shooting time etc., are widely recognized, the role of the wood surface moisture content (MC) is not evaluated in detail. In this study, the effect of wood moisture content on contact angle values, measured with distilled water and diiodomethane, on sanded birch (Betula pendula) surfaces was investigated, in order to find the relationship between them. With increasing MC from approximately 6% to 30%, increasing contact angle (decreasing surface tension) values were measured according to a logarithmic function. The function makes possible the calculation of contact angles that correspond to different MCs.

scholarly journals Biomimetic Approach for the Elaboration of Highly Hydrophobic Surfaces: Study of the Links between Morphology and Wettability

Biomimetics ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 38
Author(s):  
Quentin Legrand ◽  
Stephane Benayoun ◽  
Stephane Valette
Keyword(s):  
Contact Angle ◽  
Ginkgo Biloba ◽  
Contact Angle Hysteresis ◽  
Contact Angles ◽  
Textured Surfaces ◽  
Replication Process ◽  
Wetting Behavior ◽  
Static Contact ◽  
Biomimetic Approach ◽  
Highly Hydrophobic

This investigation of morphology-wetting links was performed using a biomimetic approach. Three natural leaves’ surfaces were studied: two bamboo varieties and Ginkgo Biloba. Multiscale surface topographies were analyzed by SEM observations, FFT, and Gaussian filtering. A PDMS replicating protocol of natural surfaces was proposed in order to study the purely morphological contribution to wetting. High static contact angles, close to 135∘, were measured on PDMS replicated surfaces. Compared to flat PDMS, the increase in static contact angle due to purely morphological contribution was around 20∘. Such an increase in contact angle was obtained despite loss of the nanometric scale during the replication process. Moreover, a significant decrease of the hysteresis contact angle was measured on PDMS replicas. The value of the contact angle hysteresis moved from 40∘ for flat PDMS to less than 10∘ for textured replicated surfaces. The wetting behavior of multiscale textured surfaces was then studied in the frame of the Wenzel and Cassie–Baxter models. Whereas the classical laws made it possible to describe the wetting behavior of the ginkgo biloba replications, a hierarchical model was developed to depict the wetting behavior of both bamboo species.

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