Search | Korea Science

Bae, Gyu-Hyun;Tong, Van-Canh;Hong, Seong-Wook
- Journal of the Korean Society for Precision Engineering
- /
- v.33 no.1
- /
- pp.53-61
- /
- 2016
Angular misalignment has a significant effect on the characteristics of angular contact ball bearings (ACBBs). This paper presents an analysis of fatigue life for ACBBs subjected to angular misalignment. A simulation model is developed with de Mul's bearing model and the ISO basic reference rating life model. Simulation is performed to calculate the life of the ACBBs subjected to angular misalignment. The numerical results show that angular misalignment influences the load distribution significantly, thus reducing the bearing rating life. The fatigue life of ACBBs is decreased by angular misalignment regardless of axial preload, external radial load and rotational speed. The results show that angular misalignment should be maintained at less than 1mrad for ACBBs.
https://doi.org/10.7736/KSPE.2016.33.1.53 인용 PDF KSCI

Jo, Jun Hyeon;Kim, Choong Hyun
- Tribology and Lubricants
- /
- v.29 no.4
- /
- pp.218-222
- /
- 2013
Water-lubricated ball bearings consist of rolling elements, an inner raceway, an outer raceway, a retainer, and an operating lubricant. In the water environment, ball bearings are required to sustain high loads at high speeds under poorly lubricated conditions. For the analysis of bearing behavior, friction torque is considered as the main factor at various flow rates, rotating speeds, and roughnesses between the rolling element and raceways. When the bearing operates at high rotating speeds, the friction torque between the raceway and rolling elements increases considerably. This frictional torque is an important factor affecting bearing reliability and life cycle duration. For understanding the flow conditions in the inner part of the bearing, this study focuses on the flow around the rotating and revolving rolling elements. A simple model of fluid flow inside the ball bearing is designed using the commercial CFD program ANSYS.
https://doi.org/10.9725/kstle-2013.29.4.218 인용 PDF KSCI

Kim, Ki-Tae;Kim, Sung-Kyun
- Proceedings of the Korean Society of Propulsion Engineers Conference
- /
- 2008.11a
- /
- pp.424-426
- /
- 2008
A parametric study was carried out to find the fuel lubrication performance of high speed small rolling element bearings. Both MIL-PRF-7808 turbine oil and JP-8 aircraft fuel were used as the lubricant to compare the operational characteristics. 17 mm inner diameter deep groove ball bearing and 20 mm cylindrical roller bearing were used. A high speed bearing test rig was developed and the testing was done with varying applied load, cooling air temperature, lubricant flow rate, and speed. Fuel caused more cage wear than oil for ball bearing with increasing axial load and rotational speed. The bearing temperature using fuel was lower than that using oil, and this seems to be the result of the high cooling capacity of fuel. According to various tests, the fuel lubrication is applicable for the lubrication on the main shaft bearings of expendable small gas turbines.
PDF