Investigation of oil-air flow and temperature for high speed ball bearings by combining nonlinear dynamic and CFD models

2021 ◽  
pp. 1-11
Author(s):  
Song Deng ◽  
Guiqiang Zhao ◽  
Dongsheng Qian ◽  
Shaofeng Jiang ◽  
Lin Hua

Abstract An improved nonlinear dynamic model of high speed ball bearings with elastohydrodynamic lubrication (EHL) is adopted to predict the movements of balls and power loss of ball bearings for defining the boundary conditions of computational fluid dynamics (CFD) model. Then, this method of combining nonlinear dynamic and CFD models is are validated through the experimental verification. Subsequently, oil-air flow and temperature distribution inside the bearing chamber are studied at low and high speeds, and light and heavy loads. The effect of nozzle's position on the formation of oil film and heat dissipation is revealed under combined loads. The research results provide a theoretical basis for engineering application of high speed rolling bearings.

Author(s):  
Dongsheng Qian ◽  
Xiaotian Xu ◽  
Song Deng ◽  
Shaofeng Jiang ◽  
Lin Hua

To accurately predict the dynamic behaviors of high speed ball bearings, an investigation on the sliding behavior of balls at high and low speeds, and light and heavy loads is necessary. However, existing nonlinear dynamic models fail to consider comprehensively key factors such as asperity and hydrodynamic tractions, time-varying friction coefficient and time-varying lubricant mode. In this work, these influencing factors are integrated into the nonlinear dynamic model to make it suitable for the working conditions of high and low speeds and light and heavy loads. The dynamic analysis provides the relation of angular speeds of balls with spin and sliding at light and heavy loads, also it reveals the number of pure rolling point under the combined effect of differential sliding and spin sliding. Research results provide a reliable mathematical model and theoretical bases for further studying the dynamic behaviors of high speed ball bearings.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Weitao Jia ◽  
Feng Gao ◽  
Yan Li ◽  
Wenwu Wu ◽  
Zhongwei Li

The paper determines the impact factors of dynamics of a motorized spindle rotor system due to high speed: centrifugal force and bearing stiffness softening. A nonlinear dynamic model of the grinding motorized spindle system considering the above impact factors is constructed. Through system simulation including phase portraits and Poincaré map, the periodic behavior and chaotic behavior of the nonlinear grinding motorized spindle system are revealed. The threshold curve of chaos motion is obtained through the Melnikov method. The conclusion can provide a theoretical basis for researching deeply the dynamic behaviors of the grinding motorized spindle system.


2018 ◽  
Vol 7 (3) ◽  
pp. 1257
Author(s):  
Khalil Azha Mohd Annuar ◽  
Nik Azran Ab. Hadi ◽  
Mohamad Haniff Harun ◽  
Mohd Firdaus Mohd Ab. Halim ◽  
Siti Nur Suhaila Mirin ◽  
...  

The overhead gantry crane systems are extensively used in harbours and factories for transportation of heavy loads. The crane speeding up, required for motion, always induces undesirable load swing. This writings present dynamic modelling of a 3D overhead gantry crane sys-tem based on closed-form equations of motion. By using the Lagrange technique, a 3D overhead gantry crane system nonlinear dynamic model is deriving. Then perform a linearization process to obtain a linear model dynamic system. Finally, simulation results systems re-sponses of the derived nonlinear and linear model are presented showing the accuracy and performance of both model.  


2015 ◽  
Vol 9 (1) ◽  
pp. 156-159 ◽  
Author(s):  
Chun L. Lei ◽  
Zhi Y. Rui ◽  
Qin Wu ◽  
Jun F. Guo ◽  
Li N. Ren

In order to more accurately calculate the film stiffness of angular contact ball bearing, it is necessary to establish the film stiffness calculation model that is consistent with reality. The frictional heat exists in high-speed ball bearings, and can impact on oil film thickness and stiffness. The calculation model of film stiffness of an angular contact ball bearing taking account of the effects of viscous heating was proposed based on the elastohydrodynamic lubrication theory. The central film thickness and film stiffness have been determined. An example was calculated with this derived equation and the result was compared with that given in other literatures. The calculation results show that the central film thickness decreases and the film stiffness increases when friction heating are considered.


2014 ◽  
Vol 971-973 ◽  
pp. 410-413
Author(s):  
Wen Juan Zhao

connecting rod mechanism under the condition of high speed operation, organization, the elastic dynamic response of not only make the institutions of trajectory deviation, also can cause fatigue failure, this paper set up an accurate view of the nonlinear dynamic model of analysis of linkage performance and characteristics of mechanical vibration, look for the causes of various vibration, and puts forward corresponding preventive measures and control strategy.


2015 ◽  
Vol 22 (9) ◽  
pp. 3358-3366 ◽  
Author(s):  
Qiang Zhai ◽  
Ke Yan ◽  
You-yun Zhang ◽  
Yong-sheng Zhu ◽  
Ya-tai Wang

Author(s):  
Changqing Bai ◽  
Hongyan Zhang ◽  
Qingyu Xu

Ball bearings are important mechanical components in high-speed turbomachinery that is liable for severe vibration and noise due to the inherent nonlinearity of ball bearings. Using experiments and the numerical approach, the nonlinear dynamic behavior of a flexible rotor supported by ball bearings is investigated in this paper. An experimental ball bearing-rotor test rig is presented in order to investigate the nonlinear dynamic performance of the rotor systems, as the speed is beyond the first synchroresonance frequency. The finite element method and two-degree-of-freedom dynamic model of a ball bearing are employed for modeling the flexible rotor system. The discrete model of a shaft is built with the aid of the finite element technique, and the ball bearing model includes the nonlinear effects of the Hertzian contact force, bearing internal clearance, and so on. The nonlinear unbalance response is observed by experimental and numerical analysis. All of the predicted results are in good agreement with experimental data, thus validating the proposed model. Numerical and experimental results show that the resonance frequency is provoked when the speed is about twice the synchroresonance frequency, while the subharmonic resonance occurs due to the nonlinearity of ball bearings and causes severe vibration and strong noise. The results show that the effect of a ball bearing on the dynamic behavior is noticeable in optimum design and failure diagnosis of high-speed turbomachinery.


Sign in / Sign up

Export Citation Format

Share Document