# Über Nabelpunkte auf einer Eifläche

@article{Bol1943berNA,
title={{\"U}ber Nabelpunkte auf einer Eifl{\"a}che},
author={Gerrit Bol},
journal={Mathematische Zeitschrift},
year={1943},
volume={49},
pages={389-410}
}
• G. Bol
• Published 1 December 1943
• Engineering
• Mathematische Zeitschrift
A gas bearing roll shell assembly comprises an outer rotatable roll shell carried on an externally pressurized gas bearing between the roll shell and a stationary axle. The roll shell has end rings, one of which has turbine buckets recessed into its bore. The axle carries a valve body having part-chordal passages aligned with the turbine buckets and a rotatable valve for selectively driving the roll shell in one direction or the other. In a modified form, selection is limited to driving in a…
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