The inner drum moves axially as it is rotating. This can be achieved by a reverse thread system.
Seal supplier catalogues will give you the recommended angle
Strain=stress/E=change in length/original length is a clue
Agree with Michael you could use a Glycodur PTFE impregnated bush which can take massive loads for their size at low speeds
Have you considered a winch to lift & lower using a steel rope.
sorry a calc mistake by me
I get 73,35 N/MM2 not 733,5 N/MM2
I have calculated the stress to be 73,35 N/MM2
not 733.5 N/MM2
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