Multicellular pump with removable cartridge

Claim 1

A multicellular centrifugal pump, comprising a motor, said motor including a motor shaft, a pump body containing a fluid circuit, said circuit including an inlet orifice and an outlet orifice, and a pump assembly disposed between said motor and said pump body, said pump assembly driven by said motor, said pump assembly receiving a fluid to be pumped from said inlet orifice and discharging said fluid to said out orifice, said pump assembly comprising a pump shaft connected to said motor shaft, a series of hydraulic and mechanical pumping elements disposed said pump shaft, an external shell enclosing said hydraulic and mechanical pumping elements, an annular duct being formed between said external shell and said hydraulic and mechanical pumping elements, an upper end flange at one end of said pump assembly, a lower end flange at the other of said pump assembly, said lower end flange being connected to said pump body by a first set of attachment means, sealing means in the region of said upper end flange, releasable coupling means connecting said pump shaft to said motor shaft, a centering sleeve disposed between said motor and said upper end flange, said centering sleeve being connected to said motor by a second set of attachment means, a hood disposed between said upper end flange and said centering sleeve, said hood being connected to said upper end flange by a third set of attachment means, and connecting means connecting said upper end flange to said lower end flange and holding said pump assembly together as a unit, wherein said pump assembly is formed as a cartridge removable as a unit.