rotating crank造句

Then, at the top of its stroke, having cleared the cylinder of exhaust gases, the piston is drawn back down by the force of the still rotating crank-shaft.
This led to the study of linkages that could generate straight lines, even if only approximately; and inspired the mathematician J . J . Sylvester, who lectured on the Peaucellier linkage, which generates an exact straight line from a rotating crank.
It's difficult to find rotating crank in a sentence. 用rotating crank造句挺难的