Propellers and vehicles equipped with such propellers

Abstract

The present invention relates to a propeller (5), preferably for hydrodynamic propulsion, comprising a hub (7) rotating about a rotation axis (X), at least three blades (9) extending from the hub (7), wherein the blades (9) are angularly evenly distributed from the hub (7) about the rotation axis (X), and wherein the propeller (5) is characterized in that the blades (9) are axially offset relative to each other along the rotation axis (X). The invention also relates to a means of transportation, preferably a marine vehicle, more preferably a ship, comprising such a propeller (5), and to a motor configured to drive the propeller (5), wherein the motor is preferably an electric motor.

Description

Technical Field

[0001] The present invention relates to a propeller, preferably for hydrodynamic propulsion, and to a vehicle equipped with such a propeller, preferably a marine vehicle, and more preferably a ship. Background Technology

[0002] Most propellers available on the market today are multi-bladed propellers, including a hub that pivots around a rotation axis, with blades extending radially from the hub. The blades are mounted on the hub and are regularly distributed around the rotation axis at an angle.

[0003] Therefore, propellers can be active, such as those mounted on vehicles like ships or aircraft, or passive, such as those mounted on turbines, wind turbines, or wind turbine generators.

[0004] When intended for use in water, the shape of the blades of an existing propeller, relative to each other, typically creates low pressure on the suction surface (usually convex) and overpressure on the pressure surface (usually concave), based on the pitch principle. Water is then expelled, thus generating thrust.

[0005] Document US 3,266,578 specifically discloses a motor-driven propeller comprising a plurality of blades, at least a portion of which are tilted relative to the hub.

[0006] Document FR 2 567 844 A1 specifically discloses a propulsion device comprising multiple single-bladed propellers that are longitudinally offset on the same axis and reduced in size.

[0007] Document US 4,514,146 specifically discloses a propulsion propeller comprising four or more blades, at least two adjacent blades tilted at leading angles oriented forward and backward respectively, and the set angle of the backward tilted blades being greater than the set angle of the forward tilted blades.

[0008] Nevertheless, most available propellers do not offer optimal efficiency, necessitating the use of high-powered motors, which results in high power consumption.

[0009] Therefore, most available propellers have turbulence problems, especially in liquid environments, due in particular to the hydrodynamic disturbances generated by the hub and the "backlash" caused by the interaction of the blades.

[0010] Therefore, for most existing propellers, the rotation of the propeller causes turbulence, which can disrupt the flow of water, reducing the efficiency of the propeller and causing vibration and noise. Summary of the Invention

[0011] The purpose of this invention is to mitigate all or some of the aforementioned disadvantages.

[0012] In particular, the object of the present invention is to provide a propeller with improved efficiency while generating less vibration and noise.

[0013] According to a first aspect, the present invention provides a propeller, preferably for hydrodynamic propulsion, comprising a hub pivoting about a rotation axis, from which at least three blades extend, the blades being regularly distributed at an angle around the rotation axis from the hub, and noteworthyly, the blades being axially offset relative to each other along the rotation axis.

[0014] Therefore, this type of propeller has improved efficiency while generating less vibration and noise. More precisely, using at least three axially offset blades allows for better fluid circulation through the propeller as it rotates about its axis of rotation. Specifically, the axial distance of each blade relative to the other blades reduces disturbances generated by the hub, particularly hydrodynamic disturbances, and the propeller's recoil coefficient. For example, when the propeller is a pusher propeller, each blade pushes back the fluid without causing any low or overpressure that adversely affects thrust.

[0015] The propeller according to the invention is advantageously and optionally accomplished by the following features, which are employed individually or in any technically possible combination thereof:

[0016] Each blade can rotate in a plane of rotation orthogonal to the axis of rotation. Therefore, each point on the blade can rotate in a plane of rotation perpendicular to the axis of rotation.

[0017] - Each blade is offset axially relative to its angularly adjacent blades at all points.

[0018] - The longitudinal axis of each blade is orthogonal to the axis of rotation.

[0019] - The blades extend radially outward from the hub relative to the axis of rotation.

[0020] - Propellers consist of exactly three, four, five, or six blades. Using this number of blades is optimal for hydrodynamic propulsion, especially for marine vehicles such as ships.

[0021] - Each blade includes a blade profile, the blade profile including a leading edge and a trailing edge, the leading edge and the trailing edge together defining a pressure surface and a suction surface.

[0022] - The blades are arranged in a regular angular pattern around the axis of rotation at 360° / Z intervals, where Z is the number of propeller blades.

[0023] - Each blade is offset axially by a given axial distance relative to its angularly adjacent blades. This given axial distance allows for optimization of propeller disturbance reduction while limiting its vibration.

[0024] - The given axial distance is the same for all blades. Therefore, each blade is axially offset by the same given axial distance relative to its angularly adjacent blades.

[0025] - The given axial distance is at least equal to the blade thickness at its center. This optimizes the reduction of disturbances.

[0026] - The center of the blade is defined as the middle of the blade's middle chord.

[0027] Each blade is connected to the hub via a blade root, which is separated from the blade roots of each of the two blades angularly adjacent to the blade by a given projected distance, the given projected distance being considered in a projection plane orthogonal to the axis of rotation. Therefore, this given projected distance allows for the creation of channels for fluid within the propeller, thereby permitting axial flow, which further reduces disturbance.

[0028] - The given projection distance is the same for all blades. Therefore, the root of each blade is separated from the roots of each of the two blades that are angularly adjacent to the blade by the same given projection distance.

[0029] Each blade is separated from the other blades by at least the given projected distance, which is considered in a projection plane orthogonal to the axis of rotation. This axially allows for a channel for fluid flow between each blade, further reducing disturbances.

[0030] For each blade, a given projection distance is less than or equal to the projection width of the blade root from the blade, the projection width being considered on a projection plane orthogonal to the axis of rotation, and the projection distance is preferably equal to the blade thickness. Therefore, this given projection distance allows for optimized disturbance reduction while maximizing propeller efficiency.

[0031] - The blades are identical. Therefore, vibration is reduced and propeller efficiency is improved.

[0032] - The blades have the same set angle. Therefore, disturbances and vibrations are reduced, while the propeller efficiency is improved.

[0033] - Each blade has a set angle that is offset from the blades adjacent to it by the same angle value, which is preferably between 5° and 10°, and more preferably equal to 5°.

[0034] - Each blade has a set angle between 15° and 45°, preferably between 30° and 45°.

[0035] - The propeller blades have a fixed pitch. Therefore, the operation of the propeller is simplified.

[0036] - The propeller blades have a variable pitch. Therefore, the propeller efficiency can be further optimized.

[0037] The hub is cylindrical. Therefore, the disturbance of the hub to the blades is limited.

[0038] - The propeller is a single piece. Therefore, the structural integrity of the propeller is optimized, and its manufacturing is simplified.

[0039] - Propellers are made of plastic, metal, or wood, such as bronze, or composite materials made of fiber-reinforced polymers, the fibers being, for example, glass or carbon fiber. The use of such materials allows for adaptation of the propeller material to its intended use. For example, bronze propellers are particularly suitable for installation on heavy-tonnage ships, such as steamships, cargo ships, container ships, supertankers, or liquefied gas carriers.

[0040] According to a second aspect, the present invention also provides a means of transportation, preferably a maritime means of transportation, preferably a small boat, more preferably a ship, comprising a propeller as described above and a motor configured to drive the propeller, the motor preferably being an electric motor.

[0041] Specifically, the propeller according to the invention is particularly suitable for installation on vehicles, preferably on marine vehicles such as ships, especially ships. Preferably, the use of an electric motor makes it possible to reduce noise and vibration transmitted to the propeller, and thus to reduce the vibration of the propeller itself when it is driven. Attached Figure Description

[0042] Other features, objects, and advantages of the invention will become apparent from the following detailed description, which is illustrative and non-limiting only and must be read with reference to the accompanying drawings, which are given by way of non-limiting example, in which:

[0043] - Figure 1 It is a schematic side view of a ship including a propeller according to an embodiment;

[0044] - Figure 2 This is a side view of the propeller according to an embodiment;

[0045] - Figure 3 yes Figure 2 The image shows another side view of the propeller, with the propeller at another rotational angle position about its axis of rotation.

[0046] - Figure 4 The projection of the propeller according to a variant embodiment onto a projection plane orthogonal to the axis of rotation of the propeller is schematically shown.

[0047] In all the accompanying drawings, similar elements are represented by the same reference numerals. Detailed Implementation

[0048] Figure 1 The illustration schematically depicts an embodiment of vehicle 1, which is preferably a maritime vehicle, more preferably a small boat, and more preferably a ship. Alternatively, according to variations not shown, vehicle 1 may be an air vehicle such as an aircraft or a drone.

[0049] The vehicle 1 includes a motor 3 and a propeller 5.

[0050] Motor 3 is configured to drive propeller 5. Preferably, motor 3 is an electric motor.

[0051] Preferably, the propeller 5 is a propeller for hydrodynamic propulsion. Therefore, the propeller 5 is configured to be driven by the motor 3 in water to rotate.

[0052] Figure 2 and Figure 3 An embodiment of propeller 5 is shown.

[0053] Advantageously, propeller 5 is a single unit. Therefore, propeller 5 is formed from units that are individual components.

[0054] Preferably, the propeller 5 is made of plastic, metal, or wood. Propeller 5 is preferably made of bronze or a composite material made of fiber-reinforced polymer. Advantageously, the fiber is glass fiber or carbon fiber.

[0055] Advantageously, the propeller 5 includes a hub 7 from which at least three blades 9 extend. Thus, the hub 7 supports the blades 9. The hub 7 is pivotable about an axis of rotation X. Therefore, the propeller 5 is also pivotable about an axis of rotation X.

[0056] Advantageously, the axis of the shaft of motor 3 coincides with the axis of rotation X.

[0057] Preferably, the hub 7 is cylindrical.

[0058] according to Figure 2 and Figure 3 In the variant shown, propeller 5 comprises exactly three blades 9. Alternatively, according to a variant not shown, propeller 5 comprises exactly four, five, or six blades 9.

[0059] Preferably, the blades 9 are identical.

[0060] Advantageously, each blade 9 includes a blade profile that includes a leading edge and a trailing edge, which together define a pressure surface and a suction surface.

[0061] Advantageously, the blades 9 have the same set angle α. Alternatively, and according to a variant not shown, each blade 9 has a set angle α that is offset by the same angle value relative to the angled adjacent blades 9, preferably between 5° and 10°, more preferably equal to 5°. For example, in the case of a propeller 5 comprising exactly four blades 9, the first blade 9 (preferably the upstream blade 9 on the hub 7) has a set angle of 30°, the second blade 9 adjacent to the first blade 9 (axially closest to the first blade 9) has a set angle of 35°, the third blade 9 adjacent to the second blade 9 has a set angle of 40°, and the fourth blade 9 adjacent to the third blade 9 has a set angle of 45°.

[0062] Preferably, each blade 9 has a set angle between 15° and 45°, and more preferably between 30° and 45°.

[0063] Preferably, the blade 9 has a fixed pitch. Alternatively, according to a variant not shown, the blade has a variable pitch. Advantageously, according to this variant not shown, the blade is pivotally attached to the hub, each blade being configured to selectively pivot about the longitudinal axis of the blade to adjust the blade pitch.

[0064] Preferably, the longitudinal axis of the blade 9 is orthogonal to the rotation axis X. In other words, for each blade 9, the longitudinal axis of the blade 9 is orthogonal to the rotation axis X. Therefore, the longitudinal axis of each blade 9 is orthogonal to the rotation axis X.

[0065] Advantageously, each blade 9 is able to rotate in a plane of rotation orthogonal to the axis of rotation X.

[0066] Preferably, each blade 9 is axially offset relative to the angled adjacent blades 9 at all points.

[0067] Advantageously, the blades 9 are regularly distributed at an angle around the axis of rotation X from the hub 7. In other words, the blades 9 are regularly distributed at an angle around the axis of rotation X every 360° / Z, where Z is the number of blades 9 of the propeller 5.

[0068] Therefore, according to Figure 2 and Figure 3In the illustrated embodiment, the propeller 5 includes three blades 9, therefore Z equals 3. The three blades 9 are arranged at intervals of 360° / 3 = 120° around the axis of rotation X. For example, in positions where the propeller 5 rotates around the axis of rotation X, one blade 9 is positioned at 120°, one blade 9 at 240°, and one blade 9 at 360°. Similarly, according to a variant not shown, where the propeller 5 includes four, five, or six blades 9, when the propeller 5 includes four blades 9, the four blades 9 are arranged at intervals of 90° around the axis of rotation X; when the propeller 5 includes five blades 9, the five blades 9 are arranged at intervals of 72° around the axis of rotation X; and when the propeller includes six blades 9, the six blades 9 are arranged at intervals of 60° around the axis of rotation X.

[0069] Preferably, the blade 9 extends radially outward from the hub 7 relative to the axis of rotation X.

[0070] Advantageously, the blades 9 are axially offset relative to each other along the axis of rotation X.

[0071] Preferably, each blade 9 is axially offset by a given axial distance Dx relative to its angled adjacent blades 9.

[0072] Advantageously, the given axial distance Dx is the same for all blades 9. In other words, each blade 9 is axially offset by the same given axial distance Dx relative to its angularly adjacent blades 9.

[0073] Advantageously, the given axial distance Dx is at least equal to the thickness E of the blade 9 at its center C.

[0074] Preferably, such as Figure 2 and Figure 3 As shown, the given axial distance Dx is equal to the thickness E of blade 9 at its center C.

[0075] Advantageously, the center C of blade 9 is defined as the middle of the middle chord of blade 9.

[0076] Preferably, each blade 9 is connected to the blade hub 7 via a blade root 11. Advantageously, the blade root 11 is separated from each of the blade roots 11 of the two blades 9 that are angularly adjacent to the blade 9 by a given projected distance Dp.

[0077] Preferably, a given projection distance Dp is considered on a projection plane P orthogonal to the rotation axis X, particularly as... Figure 3 As shown.

[0078] Advantageously, the given projection distance Dp is the same for all blades 9. Therefore, the blade root 11 of each blade 9 is separated from each of the blade roots 11 of the two blades 9 that are angularly adjacent to the blade 9 by the same given projection distance Dp.

[0079] Preferably, each blade 9 is separated from the other blades 9 by at least a given projected distance Dp.

[0080] Advantageously, for each blade 9, a given projection distance Dp is less than or equal to the projection width Lp of the blade root 11 from the blade 9, the projection width Lp being considered on a projection plane P orthogonal to the axis of rotation X.

[0081] Preferably, such as Figure 3 As shown, the projection distance Dp is equal to the thickness E of the blade 9.

[0082] Advantageously, a given projected distance Dp is equal to a given axial distance Dx. Thus, an axial passage for fluid is allowed between each blade 9, while limiting the size of the hub 7.

[0083] Advantageously, the rotor hub 7 includes a recess 13 extending radially on either side of the rotation axis X. This recess 13 allows for simple and safe transmission of torque from the electric motor 5 to the rotor hub 7 via a drive shaft. The drive shaft then includes additional ribs for the recess 13.

[0084] Figure 4 A variant embodiment of the propeller 5 is schematically shown in its projection onto a projection plane P orthogonal to the axis of rotation X of the propeller 5. The propeller 5 according to this variant embodiment differs from that previously described, and particularly in… Figure 3 The difference in the propeller 5 shown is that, for each blade 9, a given projection distance Dp is equal to the projection width Lp of the blade root 11 from the blade 9.

[0085] More generally, the propeller 5 described above can be configured to be mounted on a water turbine, marine turbine, wind turbine, or turbine.

[0086] The present invention is not limited to the embodiments and variations shown, and other embodiments will become apparent to those skilled in the art. In particular, embodiments and variations can be combined with each other.

Claims

1. A propeller (5), preferably for hydrodynamic propulsion, comprising a hub (7) pivoting about a rotation axis (X), and at least three blades (9) extending from the hub (7), the blades (9) being regularly distributed at an angle from the hub (7) about the rotation axis (X). Its features are, The blades (9) are identical and each blade (9) is axially offset by the same given axial distance (Dx) relative to the blades (9) that are angularly adjacent to it.

2. The propeller (5) according to claim 1, wherein, Each blade (9) is capable of rotating in a plane of rotation orthogonal to the axis of rotation (X).

3. The propeller (5) according to claim 1 or 2, wherein, The longitudinal axis of each blade (9) is orthogonal to the axis of rotation (X).

4. The propeller (5) according to any one of claims 1 to 3, wherein, Each blade (9) is axially offset at all points relative to the blade (9) that is angularly adjacent to it.

5. The propeller (5) according to any one of claims 1 to 4, wherein, The given axial distance (Dx) is at least equal to the thickness (E) of the blade (9) at its center.

6. The propeller (5) according to any one of claims 1 to 5, wherein each blade (9) is connected to the hub (7) via a blade root (11), the blade root (11) being separated from each of the blade roots (11) of two blades (9) angularly adjacent to the blade (9) by a given projection distance (Dp), the given projection distance (Dp) being considered on a projection plane (P) orthogonal to the axis of rotation (X).

7. The propeller (5) according to claim 6, wherein for each blade (9), a given projection distance (Dp) is less than or equal to the projection width (Lp) of the blade root (11) from 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.

8. The propeller (5) according to any one of claims 1 to 7, wherein, The blades (9) have the same set angle (α).

9. The propeller (5) according to any one of claims 1 to 7, wherein, Each blade (9) has a set angle (α) offset by the same angle value relative to the blade (9) that is angularly adjacent to it, preferably between 5° and 10°, more preferably equal to 5°.

10. The propeller (5) according to any one of claims 1 to 9, wherein, The hub (7) is cylindrical.

11. The propeller (5) according to any one of claims 1 to 10, wherein the propeller is integral.

12. A means of transport (1), preferably a maritime means of transport, more preferably a ship, comprising a propeller (5) according to any one of claims 1 to 11 and a motor (3) configured to drive the propeller (5), the motor (3) preferably being an electric motor.

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