Pivotal vane centrifugal

Claim 1

In a radial flow centrifugal pump, said pump having a drive shaft and a housing which defines an axial inlet and a collector for receiving fluid being pumped, means for varying the pump flow area comprising: impeller means, said impeller means including a plurality of pivotally mounted vanes, said vanes being pivotal about axes oriented parallelly to and disposed circumferentially about the axis of rotation of the impeller means, said vanes being mounted for pivoting adjacent their discharge ends and being characterized by increasing width from their inlet to discharge ends, said vanes cooperating to define flow channels of variable width therebetween, the shape and mounting of each of said vanes resulting in the generation of a pivotal moment in the direction of maximum flow channel width in response to the summation of the pressure and mechanical forces applied to the vanes; means for mounting said impeller means on the pump drive shaft; and spring means for loading said pivotal vanes toward the channel width position commensurate with minimum flow, said spring means generating forces substantially equal and opposite to the pressure and mechanical forces imposed on the vanes under minimum flow conditions, on the operation of said pump the pressure forces on the vanes and thus the pump blade-to-blade channel width increasing in response to increases in pump back pressure.