Entity

Time filter

Source Type


Gao Y.,East China University of Science and Technology | Li Z.,East China University of Science and Technology | Wang J.,East China University of Science and Technology | Li X.,Hangzhou Bearing Test and Research Center | An Q.,East China University of Science and Technology
Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics | Year: 2013

For the rolling element bearing-rotor system, the bearing stiffness and eventual system vibration performance are influenced by the shape and position errors of the bearing housing. In this article, a rotor supported by two cylindrical roller bearings is investigated. The load and deformation between the roller and the raceways of the bearing and the bending deformation of the rotor are analysed. An analytical model is established for calculating the radial and angular stiffnesses of the bearing considering the bearing housing deflections. Consequently, a vibration model which can consider the influences of the bearing housing deflections is developed for the bearing-rotor system. With a calculation example, the influences of the housing deflection angles on the vibration performance of the bearing-rotor system are studied numerically and a series of conclusions are obtained and explained. © 2013 IMechE. Source


Xu D.,National University of Defense Technology | Chen X.,National University of Defense Technology | Xu Y.,National University of Defense Technology | Li X.,Hangzhou Bearing Test and Research Center | Yang Y.,National University of Defense Technology
Advanced Science Letters | Year: 2011

Based on investigating the configuration of rolling element bearings, the change law of laden rolling elements is inducted under ignoring the radial clearance. Referring to impact function of a single defect on different parts by Ahmad Rafsanjani et al., a more detailed impact function for rolling element bearings is produced. Then a series of impact energy equations of a single defect on the inner race, in the outer race and on the rolling element surface are proposed. Parameters in the impact function are ascertained by experiment or simulation. According to the relationship between each component of rolling element bearings, equations of fatigue life prediction for rolling element bearings are proposed based on energy thresholds of inner ring, outer ring and rolling element. Then these equations of fatigue life prediction were verified by test life data of several sets of 6205 deep groove bearings experimented on ABLT-1A. It shows that equations of fatigue life prediction for rolling element bearings with a single surface defect on each component can depict fatigue life of rolling element bearings properly. In other words, it produces a new way for predicting fatigue life of rolling element bearings. © 2011 American Scientific Publishers. Source


Xu D.,National University of Defense Technology | Xu Y.-C.,National University of Defense Technology | Chen X.,National University of Defense Technology | Li X.-L.,Hangzhou Bearing Test and Research Center | Yang Y.-M.,National University of Defense Technology
Zhendong Gongcheng Xuebao/Journal of Vibration Engineering | Year: 2011

Most of practical signals are nonlinear and nonstationary. In order to predict the residual fatigue life of equipment based on practical signals, advanced Empirical Mode Decomposition(EMD) is proposed and these practical signals are decomposed by the advanced EMD and then a series of Intrinsic Mode Functions(IMFs) are obtained after the decomposition process. One or more IMFs will include the defect characteristic frequency of the equipment. The characteristic value in time domain of IMFs including defect characteristic frequency such as Root Mean Square or kurtosis and so on is considered as the characteristic quantity of the degradation process of a equipment and the characteristic quantity list of the degradation process will be obtained. Then a threshold value of the characteristic quantity corresponding with the fatigue failure of the equipment is determined empirically. Then the characteristic quantity of IMFs including the defect characteristic frequency in each period of the whole life cycle of the equipment are figured out and a characteristic value list is obtained. Then the list is used to train the Grey Model. The characteristic quantity trend is estimated by the trained Grey Model. The feasibility of degenerative lists based on different characteristic values is estimated. The time of usable degenerative value reaching the threshold value is estimated and will be used to evaluate the remaining fatigue life of the equipment. The prediction method is validated by vibration signals of 6205 deep groove bearing in the whole life cycle, it shows that the prediction method can provide a proper result for predicting the remaining fatigue life of small ball bearings. Source


Wang X.,Harbin Institute of Technology | Wang X.,703 Research of Institute | Wang Y.,Heilongjiang Institute of Technology | Zhao X.,Harbin Institute of Technology | Li X.,Hangzhou Bearing Test and Research Center
Journal of Mechanical Science and Technology | Year: 2015

Gear backlash and time-varying nonlinear meshing stiffness are the key design attributes of modern warship planetary gear transmission. The transmission prominent concern is teeth surface friction dynamics affect behavior and way. Therefore, the change of direction in meshing process, teeth surface friction will generate a larger oscillation, excitation response and energy consumption ways to affect dynamic characteristics of planetary gear transmission, which makes response range, dynamic behaviors more complex. Gear model and multi scale equations for transmission are established, analyzing incentive role teeth surface friction when considering dynamic and static load on influence law of gear resonance frequency response. © 2015, The Korean Society of Mechanical Engineers and Springer-Verlag Berlin Heidelberg. Source


Xu D.,National University of Defense Technology | Xu Y.,National University of Defense Technology | Chen X.,National University of Defense Technology | Li X.,Hangzhou Bearing Test and Research Center | Yang Y.,National University of Defense Technology
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2011

Microstructures of flaws of ball bearings are investigated by using field emission scanning electron microscope and it is found that both crack initiation and crack propagation are always along a certain curved surface. Propagating to a certain degree, the crack will fracture and form an elliptic flaw. Along with the ball bearing operating, not only the flaw continues to flake away, but also some new cracks initiate and propagate along new curved surfaces and fracture ultimately. There are many cross sections in the flaw. Based on this phenomenon, the critical curved surface of ball bearing is proposed and crack initiation and propagation are assumed to be on this critical curved surface. In virtue of this method, three dimension problems are converted to two dimension ones. Based on this, a modified Paris fatigue life prediction model is proposed. The fatigue life is divided into two sections: crack propagation and flaw size gain, and fatigue life are predicted by sectional Paris law. The model is validated by fatigue test life data of SKF 6205 deep groove ball bearings. In comparison with the prediction of traditional SKF L-P formulary, the proposed model produces more accurate results. © 2011 Journal of Mechanical Engineering. Source

Discover hidden collaborations