Patent ID: 7367787

Claim:
A pumping unit for a liquid medium comprising: an electric motor having a rotor and a stator, said rotor having a central bore; a pump for conveying the liquid medium and being operably connected to and driven by said electric motor, said pump being at least partially radially inside of said stator, said pump having a shaft and an eccentric internal geared wheel, said shaft having a pinion opposite to and meshing with said eccentric internal geared wheel; a housing enclosing said electric motor and said pump, wherein said rotor is on a first end of the pumping unit that is opposite to said pinion and said eccentric internal geared wheel of said pump, and wherein said rotor is resistant to rotation with respect to said shaft by a first segment of said shaft that extends axially into said central bore of said rotor; and an annular-shaped intermediate space between said rotor and said stator, wherein said housing has first and second end sides that are axially opposed to each other, wherein said first end side has an inlet for the liquid medium, wherein said second end side has an outlet for the liquid medium, and wherein the liquid medium flows from said inlet axially along said stator through said annular-shaped intermediate space through said pump and out of said outlet.