US 12,480,519 B2
Mechanism for maintaining integrity of permanent magnets in directly driven sealless pumps and turbines
Andreas Dreiss, Geestland (DE); Neil Havrilla, Coplay, PA (US); and Zachary Dennis, Emmaus, PA (US)
Assigned to Flowserve Pte. Ltd., Singapore (SG)
Filed by Flowserve Pte. Ltd., Singapore (SG)
Filed on Jan. 9, 2024, as Appl. No. 18/407,950.
Prior Publication US 2025/0226711 A1, Jul. 10, 2025
Int. Cl. F04D 29/22 (2006.01); F04D 1/04 (2006.01); F04D 7/02 (2006.01); F04D 13/02 (2006.01); F04D 13/06 (2006.01); F04D 29/58 (2006.01); H02K 1/2795 (2022.01); H02K 21/24 (2006.01)
CPC F04D 29/22 (2013.01) [F04D 7/02 (2013.01); F04D 13/06 (2013.01); H02K 1/2795 (2022.01); F04D 1/04 (2013.01); F04D 13/024 (2013.01); F04D 13/0653 (2013.01); F04D 13/0666 (2013.01); F04D 29/2227 (2013.01); F04D 29/5806 (2013.01); F04D 29/588 (2013.01); H02K 21/24 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An integral motor pump (IMP) or integral motor turbine (IMT) configured for application to a process liquid having a liquid temperature that is below ambient temperature, the IMP or IMT comprising:
a module housing configured to enable the process liquid to pass from an input thereof to an output thereof;
a stator housing contained within and fixed to the module housing;
a shaft extending axially and proximally from the stator housing along a longitudinal axis of the IMP or IMT;
an impeller rotatable with or about the shaft;
a plurality of permanent magnets fixed to a distal face of the impeller and configured to pass in proximity to a proximal face of the stator housing when the impeller rotates, the plurality of permanent magnets being arranged as an annular magnet ring that surrounds the longitudinal axis of the IMP or IMT; and
a plurality of stator coils contained within an interior of the stator housing and configured to be axially proximate the permanent magnets as the permanent magnets pass in proximity to the proximal face of the stator housing, the permanent magnets and stator coils being axially separated by a rotor-stator gap;
wherein:
the annular magnet ring is surrounded and radially bounded by an outer compression sleeve having an outer CTE that is equal to or greater than a magnet CTE of the permanent magnets; and
the annular magnet ring surrounds and is radially bounded by an inner compression sleeve having an inner CTE that is less than the magnet CTE; and
the permanent magnets being radially compressed due to unequal thermal contraction of the permanent magnets and the inner and outer compression sleeves when the inner and outer compression sleeves and the permanent magnets are cooled by the process liquid.