scholarly journals Impulse Response of the Elasto-Hydrodynamic Lubrication Film of a Rolling Bearing to Dynamic Excitation of a Flat Belt Drive

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4533
Author(s):  
Pavel Adamčík ◽  
Zuzana Murčinková
Keyword(s):  
Impulse Response ◽  
High Speed ◽  
Hydrodynamic Lubrication ◽  
Rolling Bearing ◽  
Radial Deformation ◽  
Belt Drive ◽  
Angular Contact Ball Bearing ◽  
Lubrication Film ◽  
Dynamic Excitation ◽  
Testing Bench

The impulse response of a rolling bearing and its principal component, the elasto-hydrodynamic lubrication film (EHDL), are analysed. When measuring the vibrations of bearings, we observed that the impulse response was mostly caused by defects (fatigue damage) on the raceways and/or rolling elements. However, this phenomenon can also occur in new defect-free roller bearings, where it is not commonly expected. This study presents an experiment that identifies the conditions of dynamic excitation for the impulse response of the EHDL, the source of which is not defects, but the EHDL itself. The EHDL responds in the form of impulses in case the velocity of its radial deformation is too fast. This is an unfavourable phenomenon that significantly shortens the service life of bearings. To analyse the dynamic excitation conditions, a testing bench at speeds up to 135,000 rpm with a flat belt drive was used. The testing bench enabled the formation of the so-called beat excitation from two harmonic excitation forces close in rotational frequency. The subject of this study is a defect-free high-speed double-row angular contact ball bearing used in the textile industry. We also present other physical conditions for the occurrence of undesired impulse responses that are caused by the EHDL.

Lubrication and Thermal Failure Mechanism Analysis in High-Speed Angular Contact Ball Bearing

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Wang Yunlong ◽  
Wang Wenzhong ◽  
Li Yulong ◽  
Zhao Ziqiang
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
Ball Bearing ◽  
Rolling Bearing ◽  
Operating Conditions ◽  
Contact Forces ◽  
Mechanism Analysis ◽  
Angular Contact Ball Bearing ◽  
Thermal Failure ◽  
Lubrication Performance

Lubrication analysis of rolling bearing is often conducted with assumed operating conditions, which does not consider the effect of internal dynamics of rolling bearing. In this paper, the effects of the applied load and bearing rotational speed on the lubrication performance in an angular contact ball bearing are conducted, which combines the bearing dynamic analysis and thermo-elastohydrodynamic lubrication (TEHL) analysis. First, the internal motions and contact forces are obtained from the developed bearing dynamic model, and then were integrated into the TEHL model to investigate the lubrication performance of the bearing. The results show that the rotational speed and external load has significant effects on film thickness, temperature, and power loss; if the improper axial load is applied for certain bearing speed, the lubrication performance will deteriorate and thermal failure may occur; there exists critical load or speed to keep good lubrication performance and avoid thermal failure; the skidding contributes to the thermal failure and bad lubrication performance.

Characteristics Analysis of Angular Contact Ball Bearing Based on the Oil Film Stiffness1

2011 ◽  
Vol 480-481 ◽  
pp. 599-604
Author(s):  
Zhi Feng Liu ◽  
Hao Zhou ◽  
Yong Sheng Zhao
Keyword(s):  
Ball Bearing ◽  
Hydrodynamic Lubrication ◽  
Rolling Bearing ◽  
Angular Contact Ball Bearing ◽  
Oil Film ◽  
Stiffness Model ◽  
Characteristics Analysis ◽  
Bearing Stiffness ◽  
Hydrodynamic Lubrication Theory ◽  
Film Stiffness

The bearing stiffness model is established based on the Hertz contact theory and the hydrodynamic lubrication theory of rolling bearing in this paper, the dynamic characteristics of the angular contact ball bearing and the relationship between the bearing preload, the speed and the stiffness of the angular contact ball bearing is analyzed, as well as the influence of the oil film stiffness on the bearing total stiffness. The results from taking 71924ACD/P4A bearing as an example shows that the preload and the speed have important effect on the stiffness of bearing. By the contrast of two kinds of situations, a conclusion can be drawn that when considering the oil film stiffness,the total stiffness reduces 0-40% than not considering the oil film stiffness.

scholarly journals The Effect of Lubrication on the Vibration of Roller Bearings

2018 ◽  
Vol 217 ◽  
pp. 01004
Author(s):  
N.F.M. Yusof ◽  
Z.M. Ripin
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Hydrodynamic Lubrication ◽  
Roller Bearing ◽  
Rolling Bearing ◽  
Vibration Level ◽  
Surface Degradation ◽  
Lubrication Film ◽  
Roller Bearings ◽  
High Level

Proper lubrication is crucial to ensure smooth operation in machineries. In rolling bearing, the improper lubrication may induce high friction and vibration level due to metal to metal contact between the rolling elements. In this study, the roller bearings with and without lubrication are investigated. the natural surface degradation of the roller bearing is monitored and the surface roughness is measured for the lubricant film thickness calculation. the film thickness is determined by the Hamrock-Dowson equation which showed that the grease lubricated bearing operated under the elastro-hydrodynamic lubrication, with the ratio of lubrication film thickness to the surface roughness of λ in the range of 0.9 to 3.65. the un-lubricated bearing was damaged after 20 minutes whereas the grease lubricated bearing continued to operate for 6600 minutes. the observation under microscope showed that the surface underwent smoothening process where the surface roughness decreases initially (running-in state) followed by roughening at the steady state where the surface roughness increases. At damage, the value of λ = 0.9 can be associated with the high level of the bearing vibration. the increase of vibration level becomes rapid at the critical value of λ = 1.6. As such the overall vibration level of the bearing can be related to the surface degradation and low film thickness.

Analysis of Heating Performances for Ultra-High Speed Electric Spindle Bearings Based on the Energy Theory of TEHL in Point Contact State

2010 ◽  
Vol 37-38 ◽  
pp. 135-140
Author(s):  
Song Sheng Li ◽  
Zhi Hong Hu ◽  
Peng Zhou ◽  
Peng Chen ◽  
Xiao Yang Chen ◽  
...  
Keyword(s):  
High Speed ◽  
Hydrodynamic Lubrication ◽  
Point Contact ◽  
Rolling Bearing ◽  
Total Quality ◽  
Contact State ◽  
Ultra High Speed ◽  
Air Lubrication ◽  
To Come

To analyze the lubricating state and the heating performances of the spindle bearings in ultra-high speed electric spindles, taken the characteristics of oil-air lubrication into account and based on the theories about rolling bearing dynamics and thermal elasto-hydrodynamic lubrication in point contact state, a model was built with the energy method for analyzing the heating performances the ball elements on both raceways in spindle bearings. An equation was derived for calculating the total quality of heat produced in a bearing. The influences of some basic factors such as the running speed, the axial preload, the oil viscidity, the design contact angle of bearing, and the ball materials and so on are analyzed on the heating performances in a bearing. The results show that it is easy to come into being elasto-hydrodynamic lubrication state for a bearing running in an ultra high-speed and lubricated by oil-air. It is also shown that the higher speed is, the more the quality of heat produced inside the oil films in the elasto-hydrodynamic lubrication state will be, which will bring the bearings working conditions worse.

Recent Patents on the Angular Contact Ball Bearing of High-Speed Motorized Spindle

2020 ◽  
Vol 13 ◽  
Author(s):  
Yudong Bao ◽  
Linkai Wu ◽  
Yanling Zhao ◽  
Chengyi Pan
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
Rapid Development ◽  
Ceramic Materials ◽  
Development Trend ◽  
Numerical Control ◽  
Angular Contact Ball Bearing ◽  
Practical Applications ◽  
High Speed Cutting ◽  
Advantages And Disadvantages

Background:: Angular contact ball bearings are the most popular bearing type used in the high speed spindle for machining centers, The performance of the bearing directly affects the machining efficiency of the machine tool, Obtaining a higher value is the direction of its research and development. Objective:: By analyzing the research achievements and patents of electric spindle angular contact bearings, summarizing the development trend provides a reference for the development of electric spindle bearings. Methods:: Through the analysis of the relevant technology of the electric spindle angular contact ball bearing, the advantages and disadvantages of the angular contact ball bearing are introduced, and the research results are combined with the patent analysis. Results:: With the rapid development of high-speed cutting and numerical control technology and the needs of practical applications, the spindle requires higher and higher speeds for bearings. In order to meet the requirements of use, it is necessary to improve the bearing performance by optimizing the structure size and improving the lubrication conditions. Meanwhile, reasonable processing and assembly methods will also have a beneficial effect on bearing performance. Conclusion:: With the continuous deepening of bearing technology research and the use of new structures and ceramic materials has made the bearing's limit speed repeatedly reach new highs. The future development trend of high-speed bearings for electric spindles is environmental protection, intelligence, high speed, high precision and long life.

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.

Analysis of the Lubrication Regimes at the Small End and Big End of a Connecting Rod of a High Performance Motorbike Engine

2012 ◽  
Author(s):  
Luca Bertocchi ◽  
Matteo Giacopini ◽  
Daniele Dini
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
High Performance ◽  
Hydrodynamic Lubrication ◽  
Vertical Axis ◽  
Connecting Rod ◽  
Lubrication Regimes ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Squeeze Effect

In the present paper, the algorithm proposed by Giacopini et. al. [1], based on a mass-conserving formulation of the Reynolds equation using the concept of complementarity is suitably extended to include the effects of compressibility, piezoviscosity and shear-thinning on the lubricant properties. This improved algorithm is employed to analyse the performance of the lubricated small end and big end bearings of a connecting rod of a high performance motorbike engine. The application of the algorithm proposed to both the small end and the big end of a con-rod is challenging because of the different causes that sustain the hydrodynamic lubrication in the two cases. In the con-rod big end, the fluid film is mainly generated by the relative high speed rotation between the rod and the crankshaft. The relative speed between the two races forms a wedge of fluid that assures appropriate lubrication and avoids undesired direct contacts. On the contrary, at the con-rod small end the relative rotational speed is low and a complete rotation between the mating surfaces does not occurs since the con-rod only oscillates around its vertical axis. Thus, at every revolution of the crankshaft, there are two different moments in which the relative rotational speed between the con-rod and the piston pin is null. Therefore, the dominant effect in the lubrication is the squeeze caused by the high loads transmitted through the piston pin. In particular both combustion forces and inertial forces contribute to the squeeze effect. This work shows how the formulation developed by the authors is capable of predicting the performance of journal bearings in the unsteady regime, where cavitation and reformation occur several times. Moreover, the effects of the pressure and the shear rate on the density and on the viscosity of the lubricant are taken into account.

A high-speed and long-life triboelectric sensor with charge supplement for monitoring the speed and skidding of rolling bearing

Nano Energy ◽  
2021 ◽  
pp. 106747
Author(s):  
Zhijie Xie ◽  
Yu Wang ◽  
Rensuan Wu ◽  
Jihui Yin ◽  
Di Yu ◽  
...  
Keyword(s):  
High Speed ◽  
Rolling Bearing ◽  
Long Life
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