For the lubrication of the bearings for a high pressure turbine a Witte gear pump is succesfully used.  The turbine is used for the production of liquid hydrogen. Due to the low viscosity (3 mPas), high differential pressure (29 bar) and high throughput (65 l/min) Witte Pumps & Technology was asked to desgin a special pump.

Problems:

Standard materials failed due to the low viscsity and high differential pressure.

Solution:

Test runs were done at Witte and a special combination of bearing and gear material was found which could stand the high differential pressure at the low viscosity. Inaddition to the tests at Witte the pump was tested at the University of Halle to Ensure a high life time. The pumps passed all tests with great succes. 

Conclusion:

Special selected materials can guarentee a high life time of a gear pump at heavy duty applications.

Keywords: low viscosity, high differential pressure, high throughput, lubrication, turbine