• Tribology and Lubricants
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• v.20 no.4
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• pp.177-182
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• 2004

In a turbopump cryogenic ball bearings are used to carry static and hydraulic loads, and these ball bearings must stand up to high load and speed in cryogenic circumstance. Verification of bearing performance is crucial to successful development of a turbopump. In this paper, focusing on the turbopump under developing by KARI, the performances of 203 and 207 bearings are verified through the series of tests simulating the real operating condition of turbopump.

• Tribology and Lubricants
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• v.28 no.4
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• pp.167-172
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• 2012

The turbo pump of a liquid rocket engine is composed of three main parts: the oxidizer pump, fuel pump, and turbine. Liquid oxygen ($LO_X$) is the working fluid in the cryogenic environment in the oxidizer pump, but tests are usually performed using liquid nitrogen ($LN_2$), which has a boiling point similar to that of $LO_X$ but is comparatively safer and easier to use for the test. In this study, a bearing test rig is developed and its performance is evaluated using a cryogenic ball bearing with $LN_2$ as the working fluid. Verifying the performance of the bearing test rig is crucial for ensuring correct working of the turbo pump unit in the liquid rocket engine. A stable test rig for the bearing in a cryogenic environment makes the bearing technology enhance its reliability. The test results show that the system operates stably and the requirement of performance time of 500 s is met. The test results of temperature, motor speed, and torque are discussed. The developed cryogenic bearing test rig is expected to help in widening knowledge and expanding research on ball bearings in the future.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.347-351
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• 2004

The cryogenic test facility is developed for test of deep groove ball bearings, floating ring seals, materials (steel & copper) for High Pressure Turbopump of liquid rocket engine (LRE). The cryogenic bearing test is performed to evaluate the flow rate of cooling water and the load-carrying capacity of bearings. The cryogenic seal test is performed to evaluate the determination of magnitude of leakages through the seal, a time variation of this magnitude. The test of the materials Pair is performed to evaluate its fitness for operation in the liquid oxygen medium.

• Tribology and Lubricants
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• v.27 no.1
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• pp.25-33
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• 2011

Rolling contact ball bearings are utilized almost exclusively for liquid propellant rocket engine turbopump. Turbopump ball bearings are required to endure high speed and high load for a poor lubricated condition in cryogenic environment. To evaluate bearing heat generation performance, friction torque is investigated as a function of rotation speed, bearing load and cooling flow rate through an experimental study using water coolants. Radial and axial loads are simultaneously applied to the test bearing by gas pressurized cylinder rod. Endurance performance of bearing has been also verified under the bearing required load for operating condition during total accumulated test time 2,100 sec.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.341-347
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• 2005

To perform a cryogenic development test for Tribo-elements in a turbopump, a cryogenic bearing and seal test facility (BSTF) is designed and currently under construction in KARI. The working fluid is liquid nitrogen operating at a temperature $-197^{\circ}C$. The maximum operating pressure and volume flow rate of BSTF are 100 bar and 10 liters per second, respectively. The development tests of floating ring seals, inter-propellant seals (IPS) and cryogenic ball bearings in a turbopump will be performed using the BSTF. This paper briefly described design requirements and procedures of BSTF.