Patent ID: 7530319
Filing Date: 2009-05-12
Classification: B63H

Abstract:
1. A thruster unit adapted to be installed in an operating position about a bow, a stern, or a swim platform of a vessel having a waterline for generating thrust, said thruster unit comprising: a substantially hollow casing having an upper portion and a lower portion, wherein said lower portion is situated below said waterline of said vessel while said thruster unit is in said operating position; a propeller disposed within said lower portion and having a rotating axis parallel to the direction of said thrust comprising (i) an annular shroud having an inner cylindrical wall and an outer cylindrical wall, and (ii) at least one propeller blade extending inwardly from said inner cylindrical wall; a bearing means for supporting said propeller to rotate about said rotating axis while limiting axial movement thereof, said bearing means comprising (i) a radial-outwardly facing groove circumferentially disposed around said outer cylindrical wall of said annular shroud, (ii) a radial-inwardly facing groove in said lower portion of said casing, and (iii) a plurality of rolling elements disposed within the annular space between said radial-outwardly facing groove and said radial-inwardly facing groove and roll thereon said grooves as the propeller is rotated; and Said lower portion of said casing further comprising a removable retaining disk attached thereon to jointly form said inwardly facing groove, wherein the retaining disk is detachable from the lower portion to allow said rolling elements easy access into and out of said annular space.