US4925114A Impeller bar installation and repositioning
The tube 12 is counterbored at each end into which are fitted a pair of hubs 13 having flanges 14 bolted at 15 to the two end-most discs 11, whence the rotor 10 revolves about the axis of the tube 12 and hubs 13. The discs 11 are provided with four sets of axially aligned recesses 16 …