# US 5,702,273 A · Marine propulsion system for underwater vehicles

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- Number: US 5,702,273 A
- Document ID: US5702273A
- Status: Granted
- Kind: A
- Application number: 08/649,971
- Filed: 1996-05-19
- Granted: 1997-12-30
- Earliest claimed: 1996-05-19
- Assignees: The United States of America as represented by the Secretary of the Navy
- Inventors: Chahee Peter Cho; William P. Krol, Jr.
- Web page: https://patentgrep.com/patent/US5702273A

## CPC

- B63G 8/08: Propulsion ({schnorkels B63G8/36;} nuclear propulsion B63H21/18; submerged exhausting apparatus F01N13/12)
- B63H 1/16: having a shrouding ring attached to blades
- B63H 5/16: characterised by being mounted in recesses; with stationary water-guiding elements; Means to prevent fouling of the propeller, e.g. guards, cages or screens
- B63H 23/24: electric {(dynamo-electric machines H02K)}
- B63H 2023/005: {using a drive acting on the periphery of a rotating propulsive element, e.g. on a dented circumferential ring on a propeller, or a propeller acting as rotor of an electric motor}
- B63G: OFFENSIVE OR DEFENSIVE ARRANGEMENTS ON VESSELS; MINE-LAYING; MINE-SWEEPING; SUBMARINES; AIRCRAFT CARRIERS (means of attack or defence in general, e.g. turrets F41H)
- B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00)

## Abstract

A marine propulsion system for underwater vehicles includes motor inner sor assemblies disposed in hull portions of the vehicle, fixed blades extending outwardly from an after one of the hull portions, a shroud fixed to outer ends of the fixed blades and encircling the hull portions, and a motor outer stator assembly disposed in the shroud. A rotor hub is disposed in an annular recess formed by the hull portions, the hub having permanent magnets therein adjacent the motor inner stator assemblies, and has rotor blades mounted thereon and extending outwardly therefrom and being at least in part of a permanent magnet material, outer ends of the rotor blades being adjacent the motor outer stator assembly. Activation of the stator assemblies by a polyphase A.C. power source induces movement in the permanent magnets and rotor blades to cause the rotor hub and blades to rotate. The rotation of the rotor blades serves to provide propulsive thrust to the vehicle.

## Claims

### Claim 1

A marine propulsion system for underwater vehicles, said propulsion system comprising:
motor inner stator assemblies disposed in hull portions of said vehicle;
fixed stator blades extending outwardly from an after one of said hull portions wherein said fixed stator blades are hollow;
a shroud fixed to outer ends of said fixed stator blades and encircling said hull portions wherein said shroud is hollow;
a motor outer stator assembly disposed in said shroud;
a rotor hub disposed in an annular recess formed by said hull portions, said hub having permanent magnet assemblies therein respectively adjacent said motor inner stator assemblies, and having rotor blades mounted thereon and extending outwardly therefrom and comprising permanent magnets, outer ends of said rotor blades being adjacent said motor outer stator assembly; and
electrical conductor means extending from a power source in one of said hull portions to said motor inner stator assemblies, and through said stator blades and said shroud to said motor outer stator assembly;
whereby activation of said stator assemblies induces movement in said permanent magnet assemblies and said rotor blades to cause said rotor hub and rotor blades to rotate, said rotation of said rotor blades serving to provide propulsive thrust to said vehicle.

### Claim 2

A marine propulsion system for underwater vehicles, said propulsion system comprising:
motor inner stator assemblies disposed in hull portions of said vehicle;
fixed stator blades extending outwardly from an after one of said hull portions wherein said fixed stator blades are hollow;
a shroud fixed to outer ends of said fixed stator blades and encircling said hull portions wherein said shroud is hollow;
a motor outer stator assembly disposed in said shroud; and
a rotor hub disposed in an annular recess formed by said hull portions, said hub having permanent magnet assemblies therein respectively adjacent said motor inner stator assemblies, and having rotor blades mounted thereon and extending outwardly therefrom and comprising permanent magnets wherein said rotor blades are hollow and filled with permanent magnet material, outer ends of said rotor blades being adjacent said motor outer stator assembly;
whereby activation of said stator assemblies induces movement in said permanent magnet assemblies and said rotor blades to cause said rotor hub and rotor blades to rotate, said rotation of said rotor blades serving to provide propulsive thrust to said vehicle.

### Claim 3

A marine propulsion system for underwater vehicles, said propulsion system comprising:
motor inner stator assemblies disposed in hull portions of said vehicle;
fixed stator blades extending outwardly from an after one of said hull portions;
a shroud fixed to outer ends of said fixed stator blades and encircling said hull portions;
a motor outer stator assembly disposed in said shroud; and
a rotor hub disposed in an annular recess formed by said hull portions, said hub having permanent magnet assemblies therein respectively adjacent said motor inner stator assemblies, and having rotor blades mounted thereon and extending outwardly therefrom and comprising permanent magnets wherein each of said rotor blades is a discrete permanent magnet, outer ends of said rotor blades being adjacent said motor outer stator assembly;
whereby activation of said stator assemblies induces movement in said permanent magnet assemblies and said rotor blades to cause said rotor hub and rotor blades to rotate, said rotation of said rotor blades serving to provide propulsive thrust to said vehicle.

### Claim 4

A marine propulsion system for underwater vehicles, said propulsion system comprising:
a first hull portion of the vehicle;
a rigid tube extending from an after surface of said first hull portion;
a second hull portion fixed to said tube, said tube and said second hull being immovable relative to said first hull portion, said second hull portion being spaced from said first hull portion to define therebetween an annular recess;
a motor forward stator assembly disposed in an after surface of said first hull portion and defining a forward wall of said recess;
a motor after stator assembly disposed in a forward surface of said second hull portion and defining an after wall of said recesses;
stator blades fixed to said second hull portion and extending outwardly therefrom;
a shroud fixed to outer ends of said stator blades and encircling said recess;
motor outer stator assemblies disposed in said shroud;
a rotor hub disposed in said recess and rotatable on said tube;
permanent magnets disposed in said rotor hub and adjacent, respectively, said motor forward stator assembly and said motor after stator assembly;
rotor blades comprising permanent magnets fixed to and extending outwardly from said rotor hub wherein said rotor blades are hollow and are filled with permanent magnet material, said rotor blades having outer ends adjacent said motor outer stator assemblies;
a circular band fixed to said outer ends of said rotor blades and disposed adjacent winding portions of said outer stator assemblies; and
electrical conductors extending from a power source in said first hull portion to said motor forward, after, and outer stator assemblies;
whereby electrical current from said power source is conducted by said electrical conductors to said stator assemblies to cause said permanent magnets of said rotor hub and said rotor blades to move, to cause said rotor assembly to rotate on said tube, and wherein rotation of said rotor blades serves to provide propulsive thrust to said vehicle.

### Claim 5

A marine propulsion system for underwater vehicles, said propulsion system comprising:
a first hull portion of the vehicle;
a rigid tube extending from an after surface of said first hull portion;
a second hull portion fixed to said tube, said tube and said second hull being immovable relative to said first hull portion, said second hull portion being spaced from said first hull portion to define therebetween an annular recess;
a motor forward stator assembly disposed in an after surface of said first hull portion and defining a forward wall of said recess;
a motor after stator assembly disposed in a forward surface of said second hull portion and defining an after wall of said recess;
stator blades fixed to said second hull portion and extending outwardly therefrom;
a shroud fixed to outer ends of said stator blades and encircling said recess;
motor outer stator assemblies disposed in said shroud;
a rotor hub disposed in said recess and rotatable on said tube;
permanent magnets disposed in said rotor hub and adjacent, respectively, said motor forward stator assembly and said motor after stator assembly;
rotor blades comprising permanent magnets fixed to and extending outwardly from said rotor hub wherein each of said rotor blades is a discrete permanent magnet, said rotor blades having outer ends adjacent said motor outer stator assemblies;
a circular band fixed to said outer ends of said rotor blades and disposed adjacent winding portions of said outer stator assemblies; and
electrical conductors extending from a power source in said first hull portion to said motor forward, after, and outer stator assemblies;
whereby electrical current from said power source is conducted by said electrical conductors to said stator assemblies to cause said permanent magnets of said rotor hub and said rotor blades to move, to cause said rotor assembly to rotate on said tube, and wherein rotation of said rotor blades serves to provide propulsive thrust to said vehicle.