Patent ID: 9109606
Filing Date: 2015-08-18
Classification: F04D

Abstract:
1. A pump comprising: a stator, a rotor comprising at least one impeller, and an axial balancing device arranged on a first impeller of the at least one impeller of the rotor in which a fluid duct passes, said axial balancing device comprising: a balancing chamber extending between a wall of said first impeller and the stator, and a passage arranged between said first impeller and the stator, allowing evacuation of fluid from said fluid duct to said balancing chamber; said rotor having slight axial clearance allowing limited axial shift; wherein in said axial balancing device, said passage comprises an upstream nozzle and a downstream nozzle, both axially variable, extending with a positive, zero or negative covering between two walls in a crown opposite to one another, respectively of the first impeller and of the stator, the upstream nozzle extending from a tip portion of the first impeller, and an intermediate annular chamber facing the upstream nozzle, wherein the intermediate annular chamber is arranged between walls of the first impeller and of the stator, opening downstream of the upstream nozzle and upstream of the downstream nozzle of said passage; wherein the upstream and downstream nozzles are located on a same side of the first impeller while the balancing chamber is located on an opposite side of the first impeller.