Electric marine propulsion employing switched reluctance motor drive
AssigneeBombardier Motor Corporation of America
InventorThomas E. Griffith, Sr.
Life of this patent
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Abstract
A propulsion unit for a watercraft including a prop which is adapted for producing thrust when rotated, and an electric motor drivingly coupled to the prop. The electric motor is of the switched reluctance type which includes a stator, formed of a plurality of windings, and a rotor having a plurality of poles about the circumference of the rotor. The stator windings are divided into a plurality of phases which are sequentially energized by electric current. A controller is coupled to the electric motor to determine the order and timing of phase energization. Proper sequencing of the phase energization creates a dynamic magnetic field inducing the rotor to rotate accordingly.
Claims24
A propulsion unit for a surface watercraft comprising:
- a prop adapted for producing thrust when rotated during operation;
- a switched reluctance electric motor drivingly coupled to the prop to rotate the prop at a desired speed and direction to produce the thrust, the switched reluctance electric motor comprising a rotor and a stator having a plurality of phases;
- a control unit adapted to sequentially energize the plurality of phases to induce rotation of the rotor;
- and
- wherein the propulsion unit is fixedly mounted directly to a hull of the watercraft.
A method of propulsion for a surface watercraft comprising the acts of:
- (a) providing a prop adapted for displacing water upon rotation of the prop;
- (b) drivingly coupling the prop to a switched reluctance electric motor having a stator having a plurality of phases, and a rotor having a plurality of poles;
- (c) successively energizing the phases of the stator to create magnetic flux fields to drive the rotor in rotation and thereby to produce thrust from the prop;
- (d) using a controller to direct the energizing of the phases of the stator to produce a desired speed and direction of rotation;
- and
- (e) fixedly coupling the electric motor directly to the watercraft.
A secondary propulsion unit for a surface watercraft comprising:
- a housing adapted to be submerged underwater;
- a prop rotatable to provide thrust;
- a switched reluctance electric motor housed within the housing, the switched reluctance electric motor comprising a stator having a plurality of phases and a rotor drivingly coupled to the prop;
- a control unit adapted to sequentially energize the plurality of phases to induce rotation of the rotor;
- and
- a foot-operated input device to direct the control unit to energize the plurality of phases to produce a desired rotation of the prop.
A method of propulsion for a surface watercraft comprising the acts of:
- (a) providing a prop adapted for displacing water upon rotation of the prop;
- (b) drivingly coupling the prop to a switched reluctance electric motor having a stator having a plurality of phases, and a rotor having a plurality of poles;
- (c) successively energizing the phases of the stator to create magnetic flux fields to drive the rotor in rotation and thereby to produce thrust from the prop;
- (d) using a controller to direct the energizing of the phases of the stator to produce a desired speed and direction of rotation;
- and
- (e) placing the electric motor on an interior portion of a watercraft hull and placing the prop on an exterior portion of the watercraft hull.
A method of propulsion for a surface watercraft comprising the acts of:
- (a) providing a prop adapted for displacing water upon rotation of the prop;
- (b) drivingly coupling the prop to a switched reluctance electric motor having a stator having a plurality of phases, and a rotor having a plurality of poles;
- (c) successively energizing the phases of the stator to create magnetic flux fields to drive the rotor in rotation and thereby to produce thrust from the prop;
- (d) using a controller to direct the energizing of the phases of the stator to produce a desired speed and direction of rotation;
- and
- (e) placing both the electric motor and the prop on an exterior portion of a watercraft hull.
Dependencies are inferred from the claim text.