scholarly journals The States of Oil Film Formation and Running Performance of Deep Groove Ball Bearings under Combined Loads.

2001 ◽  
Vol 67 (656) ◽  
pp. 1157-1162
Author(s):  
Chenyang ZHANG ◽  
Akira NAKAJIMA ◽  
Toshifumi MAWATARI ◽  
Hiroya ACHIHA
Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 747
Author(s):  
Taewook Ha ◽  
Dong Kyu Kim

The oil injection method was studied to maximize the cooling performance of an electric vehicle motor with a hairpin winding. The cooling performance of the motor using the oil cooling method is proportional to the contact area of the oil and the coil. A numerical analysis was conducted to examine the effect of the spray nozzle type on the oil flow. The dripping nozzle forms the thickest oil film on the coil, making it the most effective for cooling of hairpin-type motors. Subsequently, an experimental study was conducted to optimize the nozzle diameter and number of nozzles. When the inlet diameter and number was 6.35 mm and 6, the oil film formation rate was 53%, yielding the most uniform oil film. Next, an experiment was performed to investigate the effects of the oil temperature and flow rate on the oil flow. The oil film formation rate was the highest (83%) when the oil temperature was 40 °C and the flow rate was 6 LPM.


2018 ◽  
Vol 100 (6) ◽  
pp. 919-935 ◽  
Author(s):  
Dipen S. Shah ◽  
V. N. Patel ◽  
Pranav H. Darji
Keyword(s):  

Author(s):  
ONKAR L. MAHAJAN ◽  
ABHAY A. UTPAT

In deep groove ball bearings contamination of lubricant grease by solid particles is one of the main reason for early bearing failure. To deal with such problem, it is fundamental not only the use of reliable techniques concerning detection of solid contamination but also the investigation of the effects of certain contaminant characteristics on bearing performance. Nowadays the techniques such as vibration measurements are being increasingly used for on-time monitoring of machinery performance. The present work investigates the effect of lubricant contamination by solid particles on the dynamic behavior of rolling bearings, in order to determine the trends in the amounts of vibration affected by contamination in the Grease and by the bearing wear itself. Experimental tests are performed with Deep-groove ball bearings. The Dolomite powder in three concentration levels and different particle sizes was used to contaminate the grease. Vibration signals were analyzed in terms of Root Mean Square (RMS) values and also in terms of defect frequencies.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yang Liu ◽  
Jiyuan Han ◽  
Siyao Zhao ◽  
Qingyu Meng ◽  
Tuo Shi ◽  
...  

Aiming at the analysis of the dynamic characteristics of the rotor system supported by deep groove ball bearings, the dynamic model of the double-disk rotor system supported by deep groove ball bearings was established. In this paper, the nonlinear finite element method is used combined with the structural characteristics of deep groove ball bearings. Based on the nonlinear Hertz contact theory, the mechanical model of deep groove ball bearings is obtained. The excitation response results of the rotor system nodes are solved by using the Newmark-β numerical solution method combined with the Newton–Raphson iterative method. The vibration characteristics of the rotor system supported by deep groove ball bearings are studied deeply. In addition, the effect of varying compliance vibration (VC vibration) caused by the change in bearing support stiffness on the dynamics of the system is considered. The time domain and frequency domain characteristics of the rotor system at different speeds, as well as the influence of bearing clearance and bearing inner ring’s acceleration on the dynamics of the rotor system are analyzed. The research shows that the VC vibration of the bearing has a great influence on the motion of the rotor system when the rotational speed is low. Moreover, reasonable control of bearing clearance can reduce the mutual impact between the bearing rolling element and the inner or outer rings of the bearing and reduce the influence of unstable bearing motion on the vibration characteristics of the rotor system. The results can provide theoretical basis for the subsequent study of the nonlinear vibration characteristics of the deep groove ball bearing rotor system.


2018 ◽  
Vol 32 (7) ◽  
pp. 3329-3336 ◽  
Author(s):  
Guangwei Yu ◽  
Wei Xia ◽  
Zhuoyuan Song ◽  
Rui Wu ◽  
Siling Wang ◽  
...  

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