Axial flow pump with reduced height dimension

An axial flow pump comprising:

• a housing, having a bore and a fluid inlet and fluid outlet at each end of the bore;
• a magnet sleeve, supported for rotation in the bore and defining a longitudinal axis of the pump, a permanent magnet being mounted on the magnet sleeve;
• a first impeller, supported on the magnet sleeve for rotation with the magnet sleeve about the longitudinal axis to drive fluid in a flow along the bore of the housing from the fluid inlet to the fluid outlet, the flow being in the direction of the longitudinal axis, through the first impeller;
• a stator mounted around the housing and comprising a coil adapted to impart a varying magnetic field through the housing to drive the magnet sleeve about the longitudinal axis, wherein:
• the pump has a width in a first direction perpendicular to the longitudinal axis and a height in a second direction perpendicular to the longitudinal axis and to the first direction;
• the stator comprises a lamination stack on which the coil is mounted, the coil being disposed in a coil region of the lamination stack, the coil region comprising a section of the lamination stack in a plane perpendicular to the longitudinal axis, the coil region comprising the area encompassed by the coil passing through the section,
• wherein the coil region is located, with respect to the longitudinal axis, beyond a width tangent line of the bore, the width tangent line being parallel to the second direction.

An axial flow pump comprising:

• a housing, having a bore and a fluid inlet and fluid outlet at each end of the bore;
• a magnet sleeve, supported for rotation in the bore and defining a longitudinal axis of the pump, the magnet sleeve comprising a permanent magnet;
• a first impeller, supported by the magnet sleeve for rotation with the magnet sleeve about the longitudinal axis to drive fluid in a flow along the bore of the housing from the fluid inlet to the fluid outlet, the flow being in the direction of the longitudinal axis, past the first impeller;
• a stator mounted around the housing and comprising a coil arrangement adapted to impart a varying magnetic field through the housing to drive the magnet sleeve about the longitudinal axis, wherein:
• the stator comprises first and second lamination stacks, the first lamination stack being disposed on one side of the housing, and the second lamination stack being disposed on the other, opposite side of the housing, the coil arrangement comprising a first coil on the first lamination stack and a second coil on the second lamination stack, the first and second lamination stacks each defining at least a first stator tooth arranged at a first sector of the bore, the first stator tooth of the first lamination stack being diagonally opposite, across the bore of the housing, the first stator tooth of the second lamination stack;
• and wherein
• the magnet sleeve and the first and second coils are configured to be energised so that the first teeth on the first and second lamination stacks have a magnetic pole to drive a corresponding pole of the magnet sleeve in the same direction around said longitudinal axis.