Patent ID: 6250979
Filing Date: 2001-06-26
Classification: B63H,F02B

Abstract:
A boat drive comprising:a housing;a tube shaft rotatable in the housing about a shaft axis and having axially opposite front and rear ends;a hub carried on the shaft rear end;a plurality of radially projecting vanes pivotal on the hub;an axially shiftable core shaft extending coaxially in the tube shaft and having a rear end rearward of the tube-shaft rear end and a front end forward of the tube-shaft front end;means connecting the core-shaft rear end with the vanes for pivoting the vanes on the hub on axial displacement of the core shaft;a pair of oppositely directed axial-thrust bearings on the core-shaft front end;a hollow piston surrounding and containing the thrust bearings and having front and rear faces axially flanking the thrust bearings; anda cylinder fixed in the housing, surrounding the piston, and forming with the respective faces thereof front and rear compartments, whereby pressurization of the front compartment shifts the core shaft rearward and pressurization of the rear compartment shifts the core shaft forward.