Propulsion unit

Patent metadata

Field	Value
Publication number	US-10259551-B2
Application number	US-201615350082-A
Country	US
Kind code	B2
Filing date	Nov 13, 2016
Priority date	May 14, 2014
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

A support strut has an upper end rotatable supported at a bottom of a vessel and a lower end supporting a casing. A first electric motor within the casing drives a propeller via a first shaft. An annular nozzle surrounds an outer perimeter of the propeller and is fixedly supported on the casing, with a support construction comprising at least three vanes extending in the radial direction between the outer perimeter of the casing and the inner perimeter of the nozzle. A duct for water flow is formed through the interior of the annular nozzle. The propeller pulls the vessel in a driving direction. The vanes are positioned after the propeller in the driving direction of the vessel, whereby the vanes are optimized for redirecting rotational flow components of the flow produced by the propeller into axial thrust.

First claim

The invention claimed is:

1. A propulsion unit for a vessel, comprising:
a support strut extending downwards from a hull of the vessel,
a casing attached to a lower end of the support strut, the casing comprising a first end and a second end, the first end facing a front end of the vessel and the second end facing an aft end of the vessel,
a propeller being arranged at the first end of the casing, the propeller rotates in a first direction to pull the vessel in a driving direction toward the front end of the vessel and rotates in a second direction to push the vessel in a reverse direction toward the aft end of the vessel, wherein the propeller is defined by a geometry optimized for rotation in the first direction relative to the second direction,
an annular nozzle surrounding an outer perimeter of propeller blades and the annular nozzle being fixedly supported on the casing with a support construction comprising at least three vanes, said annular nozzle having an inlet opening and an outlet opening, whereby a duct for water flow is formed between the inlet opening and the outlet opening through an interior of the annular nozzle,
the propeller pulls the vessel in the driving direction, the water flow enters the propeller blades of the propeller freely from the inlet opening of the annular nozzle,
the support construction is positioned between the propeller and the support strut in the driving direction of the vessel, and
the vanes of the support construction are arranged between an outer perimeter of the casing and an inner perimeter of the annular nozzle to receive the water flow from the propeller blades of the propeller when the propeller rotates in the first direction to pull the vessel in the driving direction, wherein the vanes are disposed fully inside of the annular nozzle.

2. The propulsion unit according to claim 1 , wherein an upper end of the support strut is rotatably supported at a bottom portion of the hull.

3. The propulsion unit according to claim 1 , wherein the propulsion unit comprises a first electric motor positioned within the casing.

4. The propulsion unit according to claim 1 , wherein the propulsion unit comprises a hub attached to the first end of the casing and the propeller is attached to the hub.

5. The propulsion unit according to claim 1 , wherein the propulsion unit comprises a first shaft having a first end attached to a first electric motor and a second end attached to a hub.

6. The propulsion unit according to claim 1 , wherein the vanes in said support construction are configured to redirect rotational flow components of a rotational flow produced by the propeller into an axial thrust.

7. The propulsion unit according to claim 1 , wherein the vanes in said support construction are configured to compensate for a rotational effect caused by the propeller so that flow after the vanes is returned to an axial thrust.

8. The propulsion unit according to claim 1 , wherein the vanes in said support construction are arranged to extend in a radial direction of the annular nozzle.

9. The propulsion unit according to claim 1 , wherein a number of the vanes in the support structure is greater than a number of the propeller blades in the propeller.

10. The propulsion unit according to claim 1 , wherein the first end of the casing has a more blunt form than the second end whereby the casing is configured for propagation in the driving direction with the first end being ahead.

11. The propulsion unit according to claim 10 , wherein a first end of the support strut has a more blunt form than a second end whereby the support strut is configured for propagation in the driving direction with the first end being ahead.

12. The propulsion unit according to claim 1 , wherein the propulsion unit comprises a gearing assembly for receiving propulsion power from a motor external to the casing.

13. The propulsion unit according to claim 1 , wherein a length of the annular nozzle is in a range from 0.45 to 0.65 times a diameter of the propeller.

14. The propulsion unit according to claim 1 , wherein a center of the propeller in a longitudinal direction of the annular nozzle is in a range from 0.30 to 0.45 times a diameter of the propeller from the inlet opening of the annular nozzle.

15. The propulsion unit according to claim 1 , wherein the support structure comprises 3 to 7 vanes.

16. The propulsion unit according to claim 1 , wherein a leading edge of the support strut is inclined by an angle towards an incoming water flow, said angle of the leading edge of the support strut being in the range of 3 to 7 degrees.

17. The propulsion unit according to claim 1 , wherein an inclination angle of at least one vane with respect to a rotation axis of the propeller is between 3 to 10 degrees.

18. The propulsion unit according to claim 1 , wherein a section area between a pod and the annular nozzle at the front of the annular nozzle is 1.15 to 1.35 times a section area between a rotor disk and the annular nozzle.

19. The propulsion unit according to claim 1 , wherein a section area between a pod and an inner surface of the annular nozzle at a rear of the annular nozzle is 1.00 to 1.15 times a section area between a rotor disk and the annular nozzle.

20. The propulsion unit according to claim 1 , wherein the propeller comprises a cylindrical middle portion, a rotor disk, to which the propeller blades are fixed, and a base portion of each of the propeller blades which is fixed to the rotor disk is tilted from a rotation axis of the propeller, and a form of each of the propeller blades has a twisted form such that at a tip of each of the propeller blades, a rear end is radially further away from the base portion of the propeller blade than a front end of the propeller blade.

21. The propulsion unit according to claim 1 , wherein the vanes are inclined with respect to a rotation axis of a rotor disk, which tilting of the vanes is to an opposite direction than a tilting of the propeller blades.

22. The propulsion unit according to claim 1 , wherein the vanes in said support construction are inclined in an opposite direction relative to the propeller blades.

23. The propulsion unit according to claim 1 , wherein a first end of the support strut has a more blunt form than a second end whereby the support strut is configured for propagation in the driving direction with the first end being ahead.

Assignees

• Abb Oy

Inventors

• Veikonheimo Tomi

Classifications

• B63H5/15 Primary

  Nozzles, e.g. Kort-type · CPC title

• B63H2005/1254

  Podded azimuthing thrusters, i.e. podded thruster units arranged inboard for rotation about vertical axis · CPC title

• B63H5/125

  movably mounted with respect to hull, e.g. adjustable in direction {, e.g. podded azimuthing thrusters}({outboard units or Z-drives B63H20/00; } movably mounted for steering purposes only, {rudders carrying propellers} B63H25/42) · CPC title

• B63H21/17

  by electric motor · CPC title

• B63H2005/1258

  with electric power transmission to propellers, i.e. with integrated electric propeller motors · CPC title