Propeller and vehicle equipped with such a propeller

Abstract

The present invention relates to a propeller (5), preferably for hydrodynamic propulsion, comprising a hub (7) pivoting about an axis of rotation (X), from which hub (7) at least three blades (9) extend, the blades (9) being angularly regularly distributed from the hub (7) about the axis of rotation (X), the propeller (5) being notable in that the blades (9) are axially offset along the axis of rotation (X) relative to each other. The invention also relates to a vehicle, preferably a marine vehicle, more preferably a ship, comprising such a propeller (5) and a motor configured to drive the propeller (5), the motor preferably being an electric motor. Figure for abstract: Fig. 2

Description

Title of the invention: Propeller and vehicle equipped with such a propeller FIELD OF THE INVENTION

[0001] The present invention relates to a propeller, preferably for hydrodynamic propulsion, as well as to a vehicle, preferably a marine vehicle, more preferably a ship, provided with such a propeller. STATE OF THE ART

[0002] Most propellers currently available on the market are multi-bladed propellers, comprising a hub pivoting about an axis of rotation, from which hub the blades extend radially. The blades are located on the hub and are angularly regularly distributed on the hub about this axis of rotation.

[0003] A propeller can thus be a driving propeller, for example mounted on a vehicle such as a boat or an aircraft, or a receiving propeller, for example mounted on a turbine, a wind turbine or a wind generator.

[0004] The shape of the blades of existing propellers, which are generally arranged relative to each other according to the screw principle when they are intended for use in water, creates a depression on the extrados face, which is a generally convex face, and an overpressure on the intrados face, which is a generally concave face. The water is then ejected, thus creating thrust.

[0005] However, most of the available propellers do not offer optimal performance, so they require the use of powerful motors, which cause high energy consumption.

[0006] Thus, particularly in a liquid medium, most of the available propellers have turbulence problems, which are notably due to the hydrodynamic disturbances generated by the hub, as well as to the "recoil" notably caused by the mutual influence of the blades on each other.

[0007] Thus, for most existing propellers, the rotation of the propeller causes turbulence which can disturb the flow of water, which reduces the efficiency of the propeller, causes vibrations and noise. Statement of the invention

[0008] The present invention aims to overcome all or part of the drawbacks cited above.

[0009] The invention aims in particular to provide a propeller whose efficiency is improved, while generating less vibration and noise.

[0010] According to a first aspect, the invention provides a propeller, preferably for hydrodynamic propulsion, comprising a hub pivoting around an axis of rotation, hub from which at least three blades extend, the blades being angularly regularly distributed from the hub around the axis of rotation, the propeller being remarkable in that the blades are axially offset along the axis of rotation relative to each other.

[0011] Thus, such a propeller has improved efficiency while generating less vibration and noise. More specifically, the use of at least three axially offset blades allows for better circulation of the fluid through the propeller during rotation of the propeller around the axis of rotation. Indeed, the axial distance of each blade from the other blades reduces the disturbances generated by the hub, in particular hydrodynamic disturbances, as well as the recoil coefficient of the propeller. For example, when the propeller is a propulsive propeller, each blade pushes the fluid back without causing negative pressure or overpressure that is detrimental to the thrust.

[0012] The propeller according to the invention is advantageously and optionally supplemented by the following characteristics, taken alone or in any of their technically possible combinations:

[0013] - The blades extend radially outward from the hub, relative to the axis of rotation.

[0014] - The propeller comprises exactly three, four, five or six blades. The use of a This number of blades is optimal for hydrodynamic propulsion, particularly of marine vehicles such as ships.

[0015] - Each blade comprises a blade profile having a leading edge and a trailing edge. leak delimiting between them an intrados face and an extrados face.

[0016] - The blades are angularly regularly distributed and are arranged every 360° / Z around the axis of rotation, with Z the number of propeller blades.

[0017] - Each blade is axially offset by a predetermined axial distance relative to to an angularly adjacent blade. Such a predetermined axial distance makes it possible to optimize the reduction of propeller disturbances while limiting its vibrations.

[0018] - The predetermined axial distance is identical for all the blades. Thus, each blade is axially offset by the same predetermined axial distance relative to an angularly adjacent blade.

[0019] - The predetermined axial distance is at least equal to the thickness of the blade in its center. Thus, the reduction of disturbances is optimized.

[0020] - The center of the blade is defined as the middle of the blade's center chord.

[0021] - Each blade is connected to the hub by a blade root, the blade root being separate of each of the blade roots of the two blades angularly adjacent to the blade by a predetermined projection distance, the predetermined projection distance being considered on a projection plane orthogonal to the axis of rotation. Such a distance of predetermined projection thus makes it possible to generate a passage for the fluid within the propeller allowing axial flow, which further reduces disturbances.

[0022] - The predetermined projection distance is identical for all the blades. Thus, the blade root of each blade is separated from each of the blade roots of the two blades angularly adjacent to the blade by the same predetermined projection distance.

[0023] - Each blade is separated from the other blades by at least the projection distance predetermined, the predetermined projection distance being considered on a projection plane orthogonal to the axis of rotation. Thus, a passage for the fluid is permitted axially between each blade, which further reduces the perturbations.

[0024] - For each blade, the predetermined projection distance is less than or equal to the projection width of the blade root of the blade, the projection width being considered on a projection plane orthogonal to the axis of rotation, the projection distance preferably being equal to the thickness of the blade. Such a predetermined projection distance thus allows optimizing the reduction of the perturbations while maximizing the efficiency of the propeller.

[0025] - The blades are identical. Thus, the vibrations are reduced and the efficiency of the propeller is improved.

[0026] - The blades have the same setting angle. Thus, the perturbations and the vibrations are reduced, while improving the efficiency of the propeller.

[0027] - The blades are fixed pitch. Thus, the operation of the propeller is simplified.

[0028] - The blades are variable pitch. Thus, it is possible to further optimize the propeller efficiency.

[0029] - The hub is cylindrical. Thus, the disturbances of the hub on the blades are limited.

[0030] - The propeller is monolithic. Thus, the structural integrity of the propeller is optimized, and its manufacturing is simplified.

[0031] - The propeller is made of plastic, metal or wood, for example bronze or a composite material based on a polymer reinforced with fibers, the fibers being, for example, glass or carbon fibers. The use of such materials makes it possible to adapt the propeller material to its use. For example, a bronze propeller is particularly suitable for installation on a large tonnage vessel of the ship type, such as a cargo ship, a container ship, a supertanker or an LNG carrier.

[0032] According to a second aspect, the invention also provides a vehicle, preferably a marine vehicle, preferably a boat, more preferably a ship, comprising a propeller as previously described and a motor configured to drive the propeller, the motor preferably being an electric motor.

[0033] Indeed, the propeller according to the invention is particularly suitable for being mounted on a vehicle, preferably a marine vehicle such as a boat, in particular a ship. Preferably, the use of an electric motor makes it possible to reduce the noise as well as the vibrations transmitted to the propeller, and consequently makes it possible to reduce the vibrations of the propeller itself during its drive. DESCRIPTION OF FIGURES

[0034] Other characteristics, aims and advantages of the invention will emerge from the detailed description below, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings, given as non-limiting examples and in which: - [Fig.l] is a schematic side view of a ship comprising a propeller according to one embodiment; - [Fig.2] is a side view of a propeller according to one embodiment; - [Fig.3] is another side view of the propeller shown in [Fig.2], in which the propeller is in another angular position of rotation about its axis of rotation; - [Fig.4] schematically represents a propeller according to an alternative embodiment, in projection onto a projection plane orthogonal to the axis of rotation of the propeller.

[0035] Throughout the figures, similar elements are designated by identical references. DETAILED DESCRIPTION OF THE INVENTION

[0036] [Fig.l] schematically represents an embodiment of a vehicle 1, which is preferably a marine vehicle, preferably a boat, more preferably a ship. Alternatively, according to a variant not shown, the vehicle 1 may be an aerial vehicle such as an aircraft or a drone.

[0037] The vehicle 1 comprises an engine 3 and a propeller 5.

[0038] The motor 3 is configured to drive the propeller 5. Preferably, the motor 3 is an electric motor.

[0039] Preferably, the propeller 5 is a propeller for hydrodynamic propulsion. The propeller 5 is thus configured to be driven in rotation in the water by the motor 3.

[0040] [Fig.2] and [Fig.3] represent an embodiment of a propeller 5.

[0041] Advantageously, the propeller 5 is monolithic. The propeller 5 is thus formed from a block, in a single piece.

[0042] Preferably, the propeller 5 is made of plastic, metal or wood. The propeller 5 is preferably made of bronze or a composite material based on a polymer reinforced with fibers. Advantageously, the fibers are glass or carbon fibers.

[0043] Advantageously, the propeller 5 comprises a hub 7 from which at least three blades 9 extend. Thus, the hub 7 supports the blades 9. The hub 7 pivots about an axis of rotation X. Thus, the propeller 5 also pivots about the axis of rotation X.

[0044] Advantageously, the axis of the shaft of the motor 3 coincides with the axis of rotation X.

[0045] Preferably, the hub 7 is cylindrical.

[0046] According to the variant shown in [Fig.2] and in [Fig.3], the propeller 5 comprises exactly three blades 9. Alternatively, according to variants not shown, the propeller 5 comprises exactly four, five or six blades 9.

[0047] Preferably, the blades 9 are identical.

[0048] Advantageously, each blade 9 comprises a blade profile comprising a leading edge and a trailing edge delimiting between them an intrados face and an extrados face.

[0049] Advantageously, the blades 9 have the same pitch angle a.

[0050] Preferably, the blades 9 have a fixed pitch. Alternatively, according to a variant not shown, the blades have a variable pitch. Advantageously, according to this variant not shown, the blades are pivotally attached to the hub, each blade being configured to pivot selectively about a longitudinal axis of the blade in order to adjust the pitch of the blade.

[0051] Preferably, the longitudinal axis of the blade 9 is orthogonal to the axis of rotation X of the hub 7.

[0052] Advantageously, the blades 9 are angularly regularly distributed from the hub 7 around the axis of rotation X. In other words, the angularly regularly distributed blades 9 are arranged every 360° / Z around the axis of rotation X, with Z the number of blades 9 of the propeller 5.

[0053] Thus, according to the embodiment shown in [Fig.2] and in [Fig.3], the propeller 5 comprises three blades 9, Z is consequently equal to 3. The three blades 9 are arranged every 360° / 3 = 120° around the axis of rotation X. For example, in a rotation position of the propeller 5 around the axis of rotation X, one blade 9 is arranged at 120°, one blade 9 is arranged at 240°, and one blade 9 is arranged at 360°. Similarly, according to the variants not shown in which the propeller 5 comprises four, five or six blades 9, when the propeller 5 comprises four blades 9, the four blades 9 are arranged every 90° around the axis of rotation X, when the propeller 5 comprises five blades 9, the five blades 9 are arranged every 72° around the axis of rotation X, and when the propeller comprises six blades 9, the six blades 9 are arranged every 60° around the axis of rotation X.

[0054] Preferably, the blades 9 extend radially outwards from the hub 7, relative to the axis of rotation X.

[0055] Advantageously, the blades 9 are axially offset along the axis of rotation X relative to each other.

[0056] Preferably, each blade 9 is axially offset by a predetermined axial distance Dx relative to an angularly adjacent blade 9.

[0057] Advantageously, the predetermined axial distance Dx is identical for all the blades 9. In other words, each blade 9 is axially offset by the same predetermined axial distance Dx relative to an angularly adjacent blade 9.

[0058] Advantageously, the predetermined axial distance Dx is at least equal to the thickness E of the blade 9 at its center C.

[0059] Preferably, as shown in [Fig.2] and in [Fig.3], the predetermined axial distance Dx is equal to the thickness E of the blade 9 at its center C.

[0060] Advantageously, the center C of the blade 9 is defined as the middle of the median chord of the blade 9.

[0061] Preferably, each blade 9 is connected to the hub 7 by a blade root 11. Advantageously, the blade root 11 is separated from each of the blade roots 11 of the two blades 9 angularly adjacent to the blade 9 by a predetermined projection distance Dp.

[0062] Preferably, the predetermined projection distance Dp is considered on a projection plane P orthogonal to the rotation axis X, as is notably represented in [Fig.3].

[0063] Advantageously, the predetermined projection distance Dp is identical for all the blades 9. Thus, the blade root 11 of each blade 9 is separated from each of the blade roots 11 of the two blades 9 angularly adjacent to the blade 9 by the same predetermined projection distance Dp.

[0064] Preferably, each blade 9 is separated from the other blades 9 by at least the predetermined projection distance Dp.

[0065] Advantageously, for each blade 9, the predetermined projection distance Dp is less than or equal to a projection width Lp of the blade root 11 of the blade 9, the projection width Lp being considered on the projection plane P orthogonal to the axis of rotation X.

[0066] Preferably, as shown in [Fig.3], the projection distance Dp is equal to the thickness E of the blade 9.

[0067] Advantageously, the predetermined projection distance Dp is equal to the predetermined axial distance Dx. Thus, a passage for the fluid is allowed axially between each blade 9, while limiting the dimensions of the hub 7.

[0068] Advantageously, the hub 7 comprises a notch 13 extending radially on either side of the axis of rotation X. Such a notch 13 makes it possible to transmit torque simply and safely from the motor 5 to the hub 7, via a shaft motor. The motor shaft then includes a rib complementary to the notch 13.

[0069] [Fig.4] schematically represents an alternative embodiment of the propeller 5, in projection onto the projection plane P orthogonal to the axis of rotation X of the propeller 5. The propeller 5 according to this variant embodiment differs from the propeller 5 previously described and represented in particular in [Fig.3] in that, for each blade 9, the predetermined projection distance Dp is equal to the projection width Lp of the blade root 11 of the blade 9.

[0070] More generally, the propeller 5 previously described can be configured to be mounted on a hydraulic turbine, a hydro turbine, a wind turbine, a turbomachine.

[0071] The invention is not limited to the embodiments and variants presented and other embodiments will become clear to those skilled in the art. It is in particular possible to combine the embodiments and variants with each other.

Claims

Claims

1. Propeller (5), preferably for hydrodynamic propulsion, comprising a hub (7) pivoting about an axis of rotation (X), hub (7) from which at least three blades (9) extend, the blades (9) being angularly regularly distributed from the hub (7) about the axis of rotation (X), characterized in that the blades (9) are axially offset along the axis of rotation (X) relative to each other.

2. A propeller (5) according to claim 1, wherein each blade (9) is axially offset by a predetermined axial distance (Dx) relative to an angularly adjacent blade (9).

3. Propeller (5) according to claim 2, in which the predetermined axial distance (Dx) is at least equal to the thickness (E) of the blade (9) at its center.

4. Propeller (5) according to one of claims 1 to 3, in which each blade (9) is connected to the hub (7) by a blade root (11), the blade root (11) being separated from each of the blade roots (11) of the two blades (9) angularly adjacent to the blade (9) by a predetermined projection distance (Dp), the predetermined projection distance (Dp) being considered on a projection plane (P) orthogonal to the axis of rotation (X).

5. Propeller (5) according to claim 4, in which for each blade (9), the predetermined projection distance (Dp) is less than or equal to the projection width (Lp) of the blade root (11) of the blade (9), the projection width (Lp) being considered on a projection plane (P) orthogonal to the axis of rotation (X), the projection distance (Dp) preferably being equal to the thickness (E) of the blade (9) at its center.

6. Propeller (5) according to one of claims 1 to 5, in which the blades (9) are identical.

7. Propeller (5) according to one of claims 1 to 6, in which the blades (9) have the same pitch angle (a).

8. Propeller (5) according to one of claims 1 to 7, in which the hub (7) is cylindrical.

9. Propeller (5) according to one of claims 1 to 8, which is monolithic.

10. 9 Vehicle (1), preferably marine vehicle, more preferably ship, comprising a propeller (5) according to one of claims 1 to 9 and a motor (3) configured to drive the propeller (5), the motor (3) preferably being an electric motor.

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