Propeller, propeller propulsion system and vessel comprising propulsion system

Inactive Publication Date: 2005-08-11
ROMERO VAZQUEZ JUAN JOSE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0034] The propulsion system can comprise a nozzle concentrically located around the axis of rotation of the propeller and laterally enveloping the propeller, said nozzle having a fluid entry front end and a fluid exit rear end. The use of the nozzle can be especially advantageous in marine applications.
[0036] Each retention brace preferably has the shape of a blade in feather position for craft cruising speed (the retention braces thus have no traction effect at cruising speed). When the braces have the blade shape, they must have a symmetrical profile (with convex pressure side and suction side) for minimum aerodynamic drag.
[0043] The invention therefore increases the power output (the aforementioned traction multiplied by the speed of the craft).
[0051] In the case of the tractor propeller, to obtain a higher performance and to decrease the aerodynamic drag of the retention braces, it is appropriate for each brace to have the shape of a blade in feather position for cruising speed (i.e. the brace would have no tractor function, it would only serve to support the centrifugal force of the blades of the propeller).
[0052] To prevent or reduce vibrations caused by an excessive extension of the drive shaft with regard to the base bearings, it is appropriate for the retention braces to be perpendicular to the extension of the drive shaft, whether they have the blade shape or not.
[0060] The advantages of this invention are therefore a considerable increase of the traction and the performance of the marine propeller, aerial propeller or turbojet fan, for the same power used, i.e. consumed, with the resulting reduction of the specific fuel consumption. In the takeoff run of airplanes, for a 45 degree “upstream” rake of the blades, there is 70% more thrust for the same power consumed, which is important since this is when the thrust is most needed. Concerning the headway in boats or ships, the traction increase is less due to the head loss in the nozzle. (This is without taking into account the decrease of induced drag, which increases the performance and indirectly the thrust in the power output).

Problems solved by technology

This rotational direction is the one corresponding to the “forward” motion of the craft; if the propeller is rotated in the opposite direction, the craft “reverses” motion (with worse performance of the propeller since it is the suction side and not the pressure side the one “propelling” the water: in reverse motion, when the propeller rotates in the opposite direction, the pressure side, which is concave and acts as the suction side, stalls since the boundary layer is released, causing turbulences, which worsens the performance).
One drawback in relation, to conventional propellers, i.e. with classic propellers, with the blades perpendicular to the axis of rotation of the propeller or propellers with the blades slightly tilted “backwards” (=“downstream”) for the purpose of reducing vibrations, is that conventional propellers have a relatively low performance due to the losses caused by the blade tip vortex, crossflow at the trailing edge of the blades, and slip.
This drawback seems to be particularly severe in naval propellers, where performance is many times 60%, which means that a large part of the power supplied by the engine is lost, at least in part due to the discussed factors.

Method used

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  • Propeller, propeller propulsion system and vessel comprising propulsion system
  • Propeller, propeller propulsion system and vessel comprising propulsion system
  • Propeller, propeller propulsion system and vessel comprising propulsion system

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Embodiment Construction

[0019] A first aspect of the invention refers to a propeller comprising: [0020] a base (many times also called the “hub” of the propeller); [0021] a plurality of blades, each blade having a first end joined to the base (this end is normally known as the blade root or foot) and a second free end defining a blade tip separating a leading edge (also known as “advancing edge”) of the blade from a trailing edge (also known as “following edge”) of the blade; [0022] the propeller being configured to rotate about an axis of rotation, driven by a drive shaft of a craft, for the purpose of propelling said craft in a first direction parallel to the axis of rotation and corresponding to the forward motion direction of the craft, propelling a fluid in a second general direction opposite to said first direction; [0023] the blades extending in a third direction from the first end towards the blade tip (in most cases, said third direction coincides with the direction in which the blade section exte...

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Abstract

The invention refers to a propeller comprising a base (2, 15) and a plurality of blades (1, 14) extending from said base in an upstream tilted manner, i.e. in the direction corresponding to the forward motion direction (D1) of the craft. The blades extend in a direction forming an acute angle α with the forward motion direction, 10°≦α≦80°. The invention also refers to a propulsion system including the propeller, as well as to a craft including the propulsion system.

Description

FIELD OF THE INVENTION [0001] The invention is related to propellers, such as naval propellers, aerial propellers and fan propellers for turbojet engines. BACKGROUND OF THE INVENTION [0002] The propellers of conventional crafts comprise a base or “hub” from which the blades of the propeller extend. The blades comprise a blade body having two ends, namely, a “blade root” or “blade foot”, which is where the blade is joined to the base of the propeller, and an opposite end called “blade tip”; the tip of the blade corresponds to the point of separation between a leading edge (or advancing edge) of the blade and a trailing edge (or following edge) of the blade; with regard to the propeller, the terms leading and trailing refer to the movement of the fluid in which the propeller is operating. [0003] A propeller is normally configured so as to rotate about an axis of rotation, driven by a drive shaft joined to the engine of the craft and transmitting motion from the engine to the propeller...

Claims

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Application Information

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IPC IPC(8): B63H1/14B63H5/14B64C11/00B64C11/18B64C11/26
CPCB63H1/14B63H5/14B64C11/26B64C11/18B64C11/001
InventorROMERO VAZQUEZ, JUAN JOSE
OwnerROMERO VAZQUEZ JUAN JOSE