Locking fingers for motor shaft

Abstract

An aircraft is disclosed, comprising a main propeller (100) rotated by an electric motor (200), the electric motor having a first component (210) and a second component (220) rotatable relative to each other around a rotation axis (300), the main propeller being rotationally fixed to one of the first component and the second component, the first component and the second component being translationally movable relative to each other along a translation direction (320) defined by the rotation axis between an idle position and an operating position, comprising a recess (420, 421, 422) formed in one of the first component and the second component, the guide element being fixed to The other of the first component and the second component, the locking system has an engaged structure and a free structure, in which the guide element is at least partially inserted into the recess in the engaged structure, and in the free structure, the guide element is not at least partially inserted into the recess, the locking system is configured so that in the engaged structure, the rotation of the first component relative to the second component is limited to an angular sector less than 5°, and when the first component and the second component are in an idle position, the locking system can only be in the engaged structure, wherein the locking system is configured to switch from the engaged structure to the free structure when the motor applies a rotational torque greater than a torque threshold on the first component or on the second component.

Description

Technical Field

[0001] The present invention relates to the field of shaft locking systems in the aviation field and more particularly to the locking of shafts for aircraft propellers. Background Art

[0002] A vertical take-off aircraft is known, comprising one or several propellers for performing a substantially vertical flight phase and a propulsion device for performing a substantially lateral flight phase. Such an aircraft is thus suitable for taking off and / or landing vertically (which eliminates the need for a long take-off / landing runway) while maintaining a cruising capability similar to that of a conventional aircraft. Such an aircraft can be seen in FIG. 1A .

[0003] When such an aircraft performs a flight phase other than a vertical flight phase, this tends to produce a gas flow in a direction substantially perpendicular to the axis of rotation of one of the aircraft's propellers. For example, during the cruise phase, the flow may be substantially perpendicular to the axis of rotation of one of the propellers used during the take-off and / or landing phases.

[0004] This flow can cause the propeller to rotate. When the propeller is not driven by a motor, this is called free spinning (or windmilling) of the propeller. Thus, variable forces can be transmitted from the propeller to the aircraft, which can disturb the stability of the aircraft, especially when these changes from one motor (or propeller) to another motor (or propeller) are unpredictable and / or non-uniform.

[0005] Furthermore, this rotation can increase the aerodynamic drag of the vehicle, which is detrimental to the energy efficiency of the vehicle.

[0006] In order to overcome these problems, it is known to lock the propeller by applying an electric motor torque thereto. The energy consumption caused by the application of such a torque affects the energy efficiency of the aircraft in flight. Summary of the invention

[0007] Therefore, the present invention aims to at least partially solve these problems and therefore proposes an aircraft, comprising a main propeller driven in rotation by an electric motor, the electric motor having a first component and a second component that can be rotatably moved relative to each other along a rotation axis, the main propeller being rotationally fixed to one of the first component and the second component, the aircraft comprising a locking system, the locking system comprising a recess and a guide element, the recess being formed in one of the first component and the second component, the guide element being fixed to the other of the first component and the second component, the locking system having an engaged configuration and a free configuration, in which the guide element is at least partially inserted into the recess, and in the free configuration, the guide element is The part is not at least partially inserted into the recess, the locking system is configured so that in the engaged structure, the rotational movement of the first component relative to the second component is limited to a predetermined angular sector, for example less than 5° or for example less than 1°, the locking system is configured to switch from the engaged structure to the free structure when the motor applies a rotational torque greater than a torque threshold on the first component or on the second component, characterized in that the first component and the second component can be translated relative to each other in a translation direction defined by the rotation axis between an idle position and a working position, and characterized in that the locking system can be in the engaged structure only when the first component and the second component are in the idle position.

[0008] According to one embodiment, the guide element comprises a rolling element which can be introduced into the recess.

[0009] According to one embodiment, the aircraft is configured such that the thrust generated during driving of the main propeller by the electric motor resists switching of the first assembly and the second assembly from the operating position to the idle position.

[0010] According to one embodiment, the locking system comprises return means tending to insert the guide element into the recess when the first and second assemblies are in the rest position.

[0011] According to one embodiment, the return device comprises a support spring for urging one of the guide element and the recess towards the other and a calibration screw cooperating with the support spring to modify the stiffness of the return device.

[0012] According to one embodiment, the guide element is inserted into the recess along an insertion direction substantially perpendicular to the rotation axis and the return means tends to insert the guide element into the recess when the first and second assemblies are in the rest position.

[0013] According to one embodiment, the guide element is inserted into the recess along an insertion direction parallel or substantially parallel to the rotation axis, and the first component and the second component leave the rest position when the locking system leaves the engaged configuration.

[0014] According to one embodiment, the locking system comprises several recesses.

[0015] According to one embodiment, the locking system comprises a number of recesses equal to the number of blades of the main propeller.

[0016] According to one embodiment, the locking system comprises a number of guide elements which is smaller than the number of blades of the main propeller.

[0017] Thus, the proposed aircraft can overcome the instabilities and / or energy inefficiencies affecting known aircraft, since the locking and unlocking of its main propeller can be performed without the use of an engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1A shows a known aircraft.

[0019] FIG. 1B is an aircraft according to the present invention.

[0020] FIG. 1C shows the motor, main propeller and locking system according to a first configuration.

[0021] FIG. 1D shows the motor, main propeller and locking system according to a second configuration.

[0022] 2A-2B show a main propeller, a locking system for the configuration shown in FIG. 1C , and a motor with a first component and a second component of the motor in a first position ( FIG. 2A ) and a second position ( FIG. 2B ), respectively.

[0023] 2C-2D show the main propeller, the locking system for the configuration shown in FIG. 1D , and the motor with the first and second assemblies of the motor in a first position ( FIG. 2C ) and a second position ( FIG. 2D ), respectively.

[0024] 3A-3B illustrate, respectively, the locking system shown in FIGS. 2A-2D (FIG. 3A) and a variation thereof with alternative components (FIG. 3B).

[0025] 4A-4B show the main propeller, the locking system for the configuration shown in FIG. 1C , and the motor with the first and second components of the motor in a first position ( FIG. 4A ) and a second position ( FIG. 4B ), respectively.

[0026] 4C shows the main propeller, the locking system and the motor for the configuration shown in FIG. 1D , with the first and second assemblies thereof in a second position.

[0027] FIG. 5 shows the main propeller, the locking system and the motor with the first and second assemblies of the motor in a second position. DETAILED DESCRIPTION

[0028] FIG1B shows an aircraft according to the invention during a displacement substantially perpendicular to the axis of rotation of the aircraft's main propeller 100. This displacement may tend to produce a gas flow in a direction "e" substantially perpendicular to the axis of rotation of the aircraft's main propeller 100. The aircraft may include one or several main propellers 100. For example, the aircraft shown in FIG1B includes four main propellers.

[0029] As an example, the aircraft may include a lateral thrust device for moving the aircraft substantially perpendicular to the axis of rotation of the main propeller 100. The lateral thrust device may include, for example, a secondary propeller 999, whose axis of rotation 998 is substantially perpendicular to the axis of rotation of the main propeller 100, as shown in FIG1B .

[0030] The aircraft according to the invention may be configured to glide in a direction substantially perpendicular to the axis of rotation of the main propeller 100 when the main propeller 100 is not driven by the motor 200 particularly shown in Figures 1C and 1D. In this case, the aircraft may not include a lateral thrust device.

[0031] According to one embodiment, the electric machine 200 may be an electric motor.

[0032] 1C , the motor 200 has a first component 210 and a second component 220 which are rotatably movable relative to each other along a rotation axis 300. The main propeller 100 may be rotationally fixed to one of the first and second components 210, 220.

[0033] For example, the second assembly 220 includes a stator of the motor 200, and the first assembly 210 includes a rotor of the motor 200. The stator includes, for example, a housing of the motor 200, and the rotor includes, for example, a rotation axis of the main propeller 100. The rotation axis 300 may coincide with or substantially coincide with the axis of the main propeller 100.

[0034] Typically, the first component 210 and the second component 220 are translationally movable relative to each other along a translation direction 320 between an idle position and an operating position. For example, the translation may be caused by the generation of thrust by the main propeller 100 or by stopping the thrust generation. For example, the translation direction 320 may coincide with the rotation axis 300. For example, the idle position is the position of the rotor (or the shaft of the main propeller 100) relative to the stator (or the housing) adopted in the absence of thrust by the main propeller 100, and the operating position is the position of the rotor (or the shaft of the main propeller 100) relative to the stator (or the housing) adopted during the generation of thrust by the main propeller 100.

[0035] The translational movement of the first assembly 210 and the second assembly 220 defines a translational stroke of the first assembly 210 and the second assembly 220, which may be on the order of 2 mm or more, or comprised between 2 mm and 8 mm. According to one embodiment, the stroke corresponds to the axial clearance of the motor 200. Generally, the translational stroke may be predefined as desired.

[0036] Generally, when the motor 200 drives the main propeller 100, the main propeller 100 generates a thrust that tends to move the main propeller 100 closer to the motor 200 (or the aircraft), or to move the main propeller 100 away from the motor 200 (or the aircraft). When the thrust tends to move the main propeller 100 away from the motor 200 (or the aircraft), this is called a "pull" configuration; when the thrust tends to move them closer to each other, this is called a "push".

[0037] The aircraft includes a locking system 400 that can be disposed between the motor 200 and the main propeller 100 when the motor 200 and the main propeller 100 are mated in the traction configuration. As seen in FIG. 1D , the motor 200 can be disposed between the locking system 400 and the main propeller 100 when the motor 200 and the main propeller 100 are mated in the propulsion configuration.

[0038] Typically, the locking system 400 has an engaged configuration and a free configuration. In the engaged configuration, the rotational movement of the first component 210 relative to the second component 220 can be limited to an angular sector of less than 5°. More particularly, after adjustment and calibration, the rotational movement of the first component 210 relative to the second component 220 can be limited to an angular sector of less than 1°. Therefore, the forces applied to the aircraft by the main propeller 100 can be limited to a set of predetermined values ​​or value ranges, and / or the variability of these forces can be reduced to a minimum. When the first component 210 and the second component 220 are in the idle position, the locking system 400 can be switched to the engaged configuration. When the first component 210 and the second component 220 are in the working position, the locking system 400 cannot be switched to the engaged configuration.

[0039] Typically, the aircraft may be configured such that the thrust generated during driving of the main propeller 100 by the motor 200 resists switching of the first assembly 210 and the second assembly 220 from the working position to the idle position. Thus, the thrust may resist switching of the locking system 400 into the engaged configuration.

[0040] The locking system 400 may switch from the engaged configuration to the free configuration when the motor 200 applies a rotational torque greater than a torque threshold on the first component 210 or on the second component 220. For example, the torque may be a starting torque.

[0041] 2A , the locking system 400 generally includes a recess 420 and a guide element 410. The shape of the recess 420 may substantially correspond to the shape of the guide element 410.

[0042] For example, in FIG3A , the recess 420 has a concave bottom surface, which is semicircular here (e.g., a substantially spherical / hemispherical surface or a substantially cylindrical / hemispherical surface), and whose radius is greater than the radius of the corresponding convex surface of the guide element 410. When the concave surface of the recess 420 is substantially semi-cylindrical or cylindrical, the corresponding convex surface of the guide element 410 may be substantially spherical / hemispherical or substantially cylindrical / hemispherical. When the concave surface of the recess 420 is spherical or hemispherical, the corresponding convex surface of the guide element 410 may be spherical or hemispherical.

[0043] The bottom surface of the recess 420 may be connected to the circumferential surface of the cylindrical member 419 through a truncated conical surface or a flat surface, or may directly engage the circumferential surface of the cylindrical member 419 .

[0044] For example, in FIG. 4B , the guide element 410 is a lug, and the recess 420 is a notch having a shape complementary to that of the lug, and all or a portion of the lug engages in the notch.

[0045] For example, in FIG. 5 , the guide element 410 is a rod, and the recess 421 is a notch in which the rod is received.

[0046] Generally, the recess 420 may be formed on or in one of the first component 210 and the second component 220 , and the guide element 410 may be fixed to or in the other of the first component 210 and the second component 220 .

[0047] 5, a recess 421 is formed on or in the second component 220, and the guide element 410 is fixed to the first component 210. In FIG. 2A, a recess 420 is formed on or in the first component 210, and the guide element 410 is fixed to the second component 220.

[0048] Typically, in the engaged configuration, at least a portion of the guide element 410 is inserted into the recess 420. In contrast, in the free configuration, the guide element 410 is not at least partially inserted into the recess 420, as seen in FIG. 2B .

[0049] Typically, when the first assembly 210 and the second assembly 220 are in the working position, the recess 420 and the guide element 410 are moved away from each other along the translation direction 320. As shown in FIG. 2A, when the first assembly 210 and the second assembly 220 are in the idle position, the recess 420 and the guide element 410 are moved closer to each other along the translation direction 320.

[0050] 2A-2D , when the separation of the recess 420 from the guide element 410 is caused by the separation of the main propeller 100 from the motor 200, the locking system 400 may be considered to be configured for a traction configuration, and when the separation of the recess 420 from the guide element 410 is caused by the proximity of the main propeller 100 to the motor 200, the locking system 400 may be considered to be configured for a propulsion configuration.

[0051] As can be seen in Figs. 2A-2B, in the traction configuration, the translation of the main propeller 100 away from the motor 200 (or away from the aircraft) can also move the recess 420 away from the guide element 410 by switching the first assembly 210 and the second assembly 220 of the motor 200 to the working position. As can be seen in Figs. 2C-2D, in the propulsion configuration, according to the translation of the main propeller 100 close to the motor 200 (or the aircraft), the recess 420 can be moved away from the guide element 410 (or vice versa) by switching the first assembly 210 and the second assembly 220 of the motor 200 to the working position.

[0052] When the motor 200 and the main propeller 100 are mated in two configurations, two arrangements of the motor 200 and the locking system 400 relative to the main propeller 100 are possible. In general, a locking system 400 configured for a traction configuration can be reconfigured for a propulsion configuration (or vice versa) by reversing the orientation of the recess 420 and the guide element 410 in the translation direction 320. Thus, translation of the main propeller 100 away from the motor 200 (or the aircraft) can move the recess 420 away from the guide element 410 in a first direction along the translation direction 320 during the traction configuration, and translation of the main propeller 100 toward the motor 200 (or toward the aircraft) can move the recess 420 away from the guide element 410 in a second direction along the translation direction 320 opposite to the first direction during the propulsion configuration. This possibility will be described in detail later using Figures 2A-2D and Figures 4A-5.

[0053] As can be seen in Fig. 3A, the guide element 410 may comprise a rolling element 411 which can be introduced into the recess 420. The rolling element 411 may be arranged on a free end 412 of the guide element 410. The rolling element 411 may be made as a roller.

[0054] As seen in FIG. 2A , the locking system 400 may include return means 413 that tend to insert the guide element 410 into the recess 420 when the first assembly 210 and the second assembly 220 are in the rest position.

[0055] The return device may include a support spring 414 to push one of the guide element 410 and the recess 420 toward the other. For example, the support spring 414 may be configured to push the guide element 410 toward the recess 420.

[0056] The return device 413 may include a calibration screw 415 adapted to cooperate with the support spring 414 to modify the stiffness of the return device 413. By changing the stiffness of the return device 413, the torque threshold of the locking system 400 may be changed. A higher stiffness corresponds to a higher torque threshold, and a lower stiffness corresponds to a lower torque threshold.

[0057] Typically, during switching of the locking system 400 into the engaged configuration, the guide element 410 is inserted into the recess 420 along the insertion direction 310 .

[0058] 4A-4B , the insertion direction 310 may be substantially parallel to the translation direction 320, or to the rotation axis 300. Thus, the engaged configuration may be switched using the weight of the first assembly 210 or the second assembly 220 and / or using the weight of the main propeller 100 and / or the weight of its shaft (e.g., in the case of a substantially vertical rotation axis 300). Additionally, when the rotation axis 300 is substantially horizontal, for example, this configuration allows the locking system 400 to be brought into the engaged configuration using aerodynamic drag on the main propeller 100.

[0059] Alternatively, as can be seen in FIG. 2A , the insertion direction 310 may be substantially perpendicular to the translation direction 320, or perpendicular to the rotation axis 300. This configuration may allow reducing the length of the shaft of the main propeller 100, and / or minimizing the space requirements of the locking system 400 in the translation direction 320. When the return device 413 is present, it may facilitate the insertion of the guide element 410 into the recess 420, and may also maintain the engagement configuration, when the first assembly 210 and the second assembly 220 are in the idle position. The insertion direction 310 perpendicular to the translation direction 320 may also facilitate the calibration of the stiffness of the return device 413.

[0060] It is also contemplated to use the return device 413 when the insertion direction 310 is parallel to the translation direction 320 .

[0061] Typically, a given recess can define at least one predetermined locking position. Advantageously, in the locked position, at least one blade 101 of the main propeller 100 extends relative to the aircraft substantially in the same direction "e" as the direction of air flow around the aircraft during at least a portion of the flight phase, as shown in FIG. 1B . This is called the "marked" position. For example, during the cruise phase, the air flows around the aircraft substantially parallel to the longitudinal axis of the aircraft. In this case, the blades 101 extending radially from the axis of the main propeller 100 can be oriented so that their radial extension is parallel to the longitudinal axis 800 of the aircraft.

[0062] The marked position allows reducing the aerodynamic drag of the main propeller 100 when it is not driven by the electric motor 200 , in particular in the case of a main two-bladed or three-bladed propeller 100 .

[0063] When the main propeller 100 includes more than three blades, the marked position of the main propeller 100 is the position where the orientation of the blades provides the least resistance to the wind flow.

[0064] Typically, the locking system 400 defines at least one locking position. For example, in FIG3A , the locking system 400 defines a single locking position because it includes a single recess 420 that cooperates with a single guide element 410. In FIG5 , the locking system 400 defines several locking positions because it includes several recesses 421, 422, 423, 424.

[0065] According to one embodiment, when a plurality of locking positions are defined, each locking position places the main propeller 100 in a position where its drag is minimized. For example, a main two-bladed propeller 100 can be locked in two locking positions corresponding to the marked positions of the main propeller 100. In the case of a main three-bladed propeller 100, three locking positions corresponding to the marked positions of the main propeller 100 can be set.

[0066] The locking system 400 may include a number of recesses 421, 422 equal to the number of blades 101, 102 of the main propeller 100, such a configuration may reduce the time required to switch from the free configuration to the engaged configuration. The locking system 400 may include a number of guide elements 410, 410' equal to the number of recesses 421, 422 or the number of blades 101, 102 of the main propeller 100. According to one embodiment, the locking system 400 includes a number of guide elements 410, 410' that is less than the number of blades 101, 102 of the main propeller 100 and / or less than the number of recesses 421, 422, as seen in FIG. 3B. Although a plurality of guide elements 410, 410' allows increasing the torque threshold of the locking system 400, a number of guide elements 410, 410' that is less than the number of recesses 421, 422 and / or the number of blades 101, 102 of the main propeller 100 allows avoiding overweighting the locking system 400 and / or avoiding defining a torque threshold that is too large compared to the requirements of the aircraft. In addition, or alternatively, such a configuration can avoid making the locking system 400 hyperstatic in its engaged configuration.

[0067] 2A shows the main propeller 100, the motor 200 and the locking system 400. The main propeller 100 and the motor 200 are substantially coaxial, such that they share the same axis of rotation 300. For example, the shaft of the main propeller 100 is fixed to the rotor of the motor 200.

[0068] The motor 200 and the main propeller 100 are configured to cooperate in a towing configuration. A locking system 400 is provided between the main propeller 100 and the motor 200 .

[0069] The first component 210 and the second component 220 of the motor 200 are shown in an idle position, which allows the guide element 410 of the locking system 400 to be inserted into the recess 420 of the locking system 400 along the insertion direction 310 substantially perpendicular to the rotation axis 300, and thus allows the locking system 400 to be switched into its engaged configuration. The locking system 400 is held in the engaged configuration by the cooperation between the free end 412 of the guide element 410 and the recess 420. This cooperation can be broken when the motor 200 applies a torque greater than a torque threshold of the locking system 400 to the first component 210 and the second component 220.

[0070] FIG3A shows a cross-sectional view of the locking system 400 shown in FIG2A . The locking system 400 includes a return device 413, which tends to insert the free end 412 of the guide element 410 into the recess 420. The stiffness of the return device 413 at least partially determines the torque threshold of the locking system 400. The return device 413 includes a support spring 414 and a calibration screw 415, which cooperate to change the stiffness of the return device 413.

[0071] The guide element 410 comprises a finger, the free end 412 of which is inserted into a cylindrical part 419 having a recess 420. The cylindrical part 419 may be attached to the shaft of the motor 200 and / or to the shaft of the main propeller 100.

[0072] The finger is slidingly mounted in a housing of the return device 413 , which serves to mount the return device 413 , to guide the finger, and to arrange a support spring 414 and a calibration screw 415 .

[0073] The recess 420 is presented on the circumferential surface of the cylindrical component 419, opposite to the free end 412 of the guide element 410. This arrangement may facilitate the insertion of the guide element 410 into the recess 420 along the insertion direction 310.

[0074] The circumferential surface may include a flat portion in which the recess 420 is formed. The flat portion may allow increasing the threshold of the torque of the locking system 400 and / or cause a progressive compression of the return device 413. In the event of an additional torque being precisely applied to separate the guide element 410 from the recess 420 (which may occur, for example, during turbulence), the flat portion allows bringing the guide element back into the recess 420. The size of the flat portion may be determined based on the number of blades, and / or the number of recesses 420 and / or the guide element 410, and / or based on the threshold of the torque of the locking system 400.

[0075] According to one embodiment, the cylindrical member 419 may have a thickness equal to or less than the translation stroke (measured in a direction along the translation stroke). For example, the thickness of the cylindrical member 419 may be slightly less than the translation stroke to disengage from the guide element during the working position.

[0076] This configuration allows a single locking system 400 to ensure the locking and unlocking of the motor 200 and the main propeller 100 when they cooperate in traction as well as in propulsion, possibly using a single cylindrical part 419. In this case, the idle position is arranged between the two working positions.

[0077] When the cylindrical component includes a circumferential flange 418 (described in detail below), the thickness of the cylindrical component 419 does not take into account the thickness of the circumferential flange 418.

[0078] The recess 420 may be formed as a groove. When the first assembly 210 and the second assembly 220 are switched from the working position to the idle position, the groove allows the guide element 410 to be advantageously inserted into the recess 420. For example, when the finger passes through the groove, the force required to compress the return device 413 to insert the finger into the recess 420 is small.

[0079] When the groove has a depth (measured from the circumferential surface of the cylindrical part 419 towards the axis of rotation) equal to the depth of the recess 420, when the finger passes through the groove, it is possible that the return device 413 is not compressed. In this case, it can be said that the locking system 400 has two insertion directions: the first insertion direction 310 is perpendicular to the translation direction 320 (for example, due to the orientation of the return device 413), and the second insertion direction is defined by the groove.

[0080] The groove may extend from the recess 420 in the translation direction 310 (or parallel thereto), or may follow a spiral path around the axis of rotation. Its width (which may be measured in the circumferential direction of the cylindrical component 419) may be constant or may vary depending on the distance from the recess 420.

[0081] The groove may have a substantially semi-cylindrical, or even semi-conical section (measured along the direction / path in which it extends from the recess 420), wherein the base of the cone is oriented away from the recess 420 to guide the recess 420 towards the guide element 410 during switching to the idle position. Other shapes of the movable part 210 may be designed to facilitate the introduction of the guide element during the translational movement.

[0082] As can be seen in FIG. 2B , the locking system 400 is configured to switch from the engaged configuration to the free configuration when the motor 200 applies a rotational torque greater than a torque threshold on the first component 210 and the second component 220. The torque threshold may be defined based on the number of blades of the main propeller 100. For example, a threshold substantially equal to 10 Nm or more may be sufficient for a small main propeller 100 having at least two blades, and / or a threshold of 500 Nm or less may be sufficient for a main propeller 100 having six blades or less. For example, when the main propeller 100 is a three-blade, four-blade, or five-blade propeller, the threshold may be between 10 Nm and 500 Nm, or between 10 Nm and 350 Nm, or between 350 Nm and 500 Nm, with an increased number of blades corresponding to a higher threshold. Thus, under normal flight conditions, the torque applied to the locking system 400 by the flow over the main propeller 100 is insufficient to unlock it, but the torque applied to the locking system 400 by the motor 200 is sufficient to unlock the main propeller 100 .

[0083] When the locking system 400 leaves the engaged configuration, the main propeller 100 is driven by the motor 200, thus generating a thrust that tends to move the recess 420 away from the guide element 410 along a translation direction 320 that is substantially parallel to the rotation axis 300 (and therefore substantially perpendicular to the translation direction 310). The thrust also tends to place the first assembly 210 and the second assembly 220 of the motor 220 in the working position. When the first assembly 210 and the second assembly 220 are in the working position, the guide element 410 and the recess 420 disengage from each other, thereby preventing the locking system 400 from returning to the engaged configuration.

[0084] Furthermore, the thrust serves to maintain the locking system 400 in the free configuration as it maintains the first assembly 210 and the second assembly 220 in the working position.

[0085] When the motor 200 stops driving the main propeller 100 , the first assembly 210 and the second assembly 220 may return to an idle position.

[0086] Since the main propeller 100 and the motor 200 are mated in the traction configuration, and since the recess 420 is fixed to the shaft of the main propeller 100, switching to the working position causes the recess 420 to separate from the motor 200 along the translation direction 320, to which the guide element 410 is attached. Likewise, switching to the idle position causes the recess 420 to approach the motor 200 (and therefore, the guide element 410) along the translation direction 320.

[0087] As seen in FIG. 2A , the cylindrical component 419 may include a circumferential flange 418. The circumferential flange 418 may define a limit to the translational travel of the first component 210 and the second component 220 relative to each other, or a limit to the translational travel of the recess 420 and the guide element 410 relative to each other. The circumferential flange 418 may, for example, rest on the guide element 410 to prevent the recess 420 from exceeding the free end 412 of the guide element 410, for example by limiting the approach of the recess 420 to the motor 200 along the translation direction 320. According to one embodiment, the housing also allows the position of the finger relative to the recess 420 along the translation direction 320 to facilitate reconfiguration of the locking system 400 during a change in the fit between the main propeller 100 and the motor 200. When the circumferential flange is present, reconfiguration of the locking system 400 may include a reversal of the cylindrical component 419 relative to the translation direction 320.

[0088] FIG. 2C shows a motor 200, a main propeller 100, and a locking system 400, with the first assembly 210 and the second assembly 220 of the motor being shown in an idle position. The main propeller 100 can be connected to the motor 200 in the same manner as the main propeller 100 is connected to the motor 200 in FIG. 2A. The motor 200 and the main propeller 100 are configured to cooperate in a propulsion configuration. The motor 200 is disposed between the locking system 400 and the main propeller 100. The locking system 400 can be substantially the same as the locking system shown in FIG. 2A.

[0089] 2D , when the motor 200 applies a rotational torque greater than the torque threshold on the first assembly 210 and the second assembly 220, the locking system 400 leaves its engaged configuration and the motor 200 drives the main propeller 100. The thrust generated by the main propeller 100 tends to bring the main propeller 100 closer to the motor 200 along the translation direction 320.

[0090] Since the main propeller 100 and the motor 200 are matched in the propulsion configuration, and since the recess 420 is fixed to the shaft of the main propeller 100, switching to the working position causes the recess 420 to separate from the motor 200 along the translation direction 320, while the guide element 410 is attached to the housing. Likewise, switching to the idle position causes the recess 420 to approach the motor 200 along the translation direction 320.

[0091] When the housing of the return device 413 allows adjusting the position of the finger relative to the recess 420 along the translation direction 320, according to one embodiment, the locking system 400 can be reconfigured by changing the cooperation between the main propeller 100 and the motor 200, by reversing the order of the recess 420 and the insertion element 410 along the translation direction 320. When the circumferential flange is present, the reconfiguration of the locking system 400 may comprise the reversal of the cylindrical part 419 relative to the translation direction 320.

[0092] FIG3B shows an alternative component for the locking system 400 shown in FIG3A . It is a variation of the cylindrical component 419, comprising several recesses 421, 422. The recesses 421, 422 are present on the circumferential surface of the cylindrical component 419. At least one of the recesses 421, 422 may be formed in a flat portion of the circumferential surface, or, as seen in FIG3B , each recess 421, 422 may be formed in a flat portion of its own circumferential surface.

[0093] FIG4A shows a motor 200, a main propeller 100, and a locking system 400. The main propeller 100 can be connected to the motor 200 in the same manner as the main propeller 100 is connected to the motor 200 in FIG2A. The main propeller 100 and the motor 200 are configured to cooperate in a traction configuration. The locking system 400 is disposed between the motor 200 and the main propeller 100.

[0094] The motor 200 is shown with its first component 210 and second component 220 in an idle position, which allows the guide element 410 of the locking system 400 to be inserted / assembled into the recess 420 of the locking system 400 along an insertion direction 310 substantially parallel to the rotation axis 300 and, thereby, allows the locking system 400 to switch to its engaged configuration.

[0095] 4B , the guide element 410 comprises a lug, the free end 412 of which can be inserted into a cylindrical part 419 having a recess 420. The lug protrudes in the insertion direction 310. The guide element 410 can be made as a ring arranged around the axis 300 of rotation.

[0096] The recess 420 is present on the axial surface of the cylindrical part 419, opposite the free end 412 of the guide element 410. This arrangement may facilitate the insertion of the guide element 410 into the recess along the insertion direction 310. The cylindrical part 419 may be substantially hollow, for example, it may be made as a ring around the axis of the main propeller 100.

[0097] The recess 420 is made into a notch, and the surface of the recess substantially corresponds to the surface of the free end 412 of the insertion element 410. These corresponding surfaces of the recess 420 and the guide element 410 can cooperate with each other so that when the motor 200 applies a rotational torque greater than the torque threshold on the first component 210 and the second component 220 to unlock the locking system 400, these surfaces push the recess 420 and the guide element 410 to move away from each other along the translation direction 320 substantially parallel to the rotation axis 300 (and, therefore, substantially parallel to the insertion direction 310).

[0098] The torque threshold of locking system 400 may be determined at least in part by the geometry of at least one of the corresponding surfaces of the lug and the notch. The structure of locking system 400 (and therefore the structure of the aircraft) may be simplified by ensuring that first component 210 and second component 220 move away from the rest position when locking system 400 leaves the engaged configuration.

[0099] For example, the torque threshold may vary depending on the depth of the recess 420. For example, a relatively deep recess 420 may provide a greater torque threshold than a relatively shallow recess 420.

[0100] Alternatively or in addition, the torque threshold may vary depending on the stiffness of the edge of the recess 420 in the direction of rotation of the main propeller 100. For example, for two recesses 420 of the same depth, the recess having a relatively steep edge in the direction of rotation of the main propeller 100 may impart a greater torque threshold than the recess having a relatively less steep edge.

[0101] According to one embodiment, the edge of the recess 420 in the rotation direction of the main propeller 100 may define an inner angle of 60°-120° in the rotation plane of the main propeller 100 .

[0102] According to one embodiment, the perimeter of the recess 420 can be made rounded. Such a configuration allows reducing the wear on the locking system 400.

[0103] When one of the edges of the recess 420 is rounded in the direction of rotation of the main propeller 100 , the angle may be considered to be defined in part by a tangent to the edge at the level of its connection with the periphery of the recess 420 .

[0104] To reduce wear of the locking system 400 (or its recess 420 or its guide element 410), the guide element 410 may include a rolling element at the free end 412 of the lug. In this case, the notch may have a rounded surface, as described above for the recess 420 shown in FIG. 3A.

[0105] Since the recess 420 is fixed to the shaft of the main propeller 100 and since the guide element 410 is attached to the housing of the motor 200 , this separation also tends to translate the first assembly 210 and the second assembly 220 of the motor 200 relative to each other along the translation direction 320 towards the working position.

[0106] When the locking system 400 has left its engaged configuration, the motor 200 can drive the main propeller 100, generating thrust. Since the main propeller 100 and the motor 200 are engaged in the traction configuration, this thrust can tend to move the recess 420 away from the guide element 410 until the guide element 410 and the recess 420 disengage from each other, thereby preventing the locking system 400 from returning to the engaged configuration.

[0107] In addition, the thrust is used to keep the locking system 400 in the free configuration because it holds the first assembly 210 and the second assembly 220 in the working position. When the motor 200 stops driving the main propeller 100, the first assembly 210 and the second assembly 220 can return to the idle position, which allows the locking system 400 to switch to the engaged configuration.

[0108] FIG. 4C shows the main propeller 100, the locking system 400 and the motor. The main propeller 100 can be connected to the motor 200 in the same manner as the main propeller 100 is connected to the motor 200 in FIG. 2A. The main propeller 100 and the motor 200 are configured to cooperate in a propulsion configuration. The motor 200 is disposed between the main propeller 100 and the locking system 400. The locking system 400 is substantially the same as the locking system 400 shown in FIG. 4B. It can be seen that the locking system 400 shown in FIG. 4C is reversed relative to the locking system 400 shown in FIG. 4B along the translation direction 320 relative to the orientation of the motor 200 and the main propeller 100. Therefore, in FIG. 4C, the guide element 410 is disposed between the main propeller 100 and the recess 420.

[0109] FIG5 shows the main propeller 100, the locking system 400 and the motor 200. The main propeller 100 can be connected to the motor 200 in the same manner as the main propeller 100 is connected to the motor 200 in FIG2A. The main propeller 100 and the motor 200 are configured to cooperate in the traction configuration. The locking system 400 is disposed between the motor 200 and the main propeller 100.

[0110] The motor 200 is shown with its first assembly 210 and its second assembly 220 in the working position, and the locking system 400 is shown in its free configuration. During its driving by the motor 200, the main propeller 100 generates a thrust tending to keep the first assembly 210 and the second assembly 220 in the working position, and therefore also tending to keep the locking system 400 in the free configuration.

[0111] The locking system comprises at least two recesses 421, 422 and two guide elements 410, 410'. Other multiple recesses 421, 422 and / or guide elements 410, 410' are also contemplated. For example, in FIG. 5 , the locking system comprises four recesses 421, 422, 423, 424 and two guide elements 410, 410'.

[0112] Each guide element 410, 410' comprises a rod supported vertically and / or radially with respect to the rotation axis 300. Each recess 421, 422 is formed on an axial surface of an opposing cylindrical part 419 of the guide element 410, 410'. The recess 421, 422 may be made as a notch.

[0113] The cylindrical member 419 is arranged around the rotation axis 300. When the cylindrical member 419 is fixed to the housing of the motor 200 or the aircraft, it may have a ring shape in which the shaft of the main propeller 100 or the rotor of the motor 200 (or more specifically, the output shaft of the motor 200) may be arranged.

[0114] When the locking system 400 is switched to its engaged configuration, the rod is inserted / fitted into the recesses 421, 422. To ensure insertion and removal (during switching to the free configuration), the rod can be fixed to the first component 210 (for example, to the shaft of the main propeller 100), and the cylindrical part 419 can be fixed to the second component 220 (for example, to the housing of the motor 200).

[0115] When the rod is fixed to a shaft (e.g., the shaft of the main propeller 100), its diameter may be smaller than the diameter of the shaft. For example, the diameter of the rod may be comprised between 1 / 20 and 1 / 8 of the diameter of the shaft, depending on the number and shape of the blades of the main propeller 100. When the rod extends radially from the shaft, it may be attached in a radial hole of the shaft. According to one embodiment, such a hole may be a through hole to arrange two rods, which are diametrically opposite and fixed to each other.

[0116] When the main propeller 100 is not driven by the motor 200, the first assembly 210 and the second assembly 220 of the motor 200 can be switched to their idle positions. Since the main propeller 100 and the motor 200 are matched in a traction configuration, this switching is accompanied by the main propeller 100 approaching the motor 200 along a translation direction 320 substantially parallel to the rotation axis 300. Since the rod is fixed to the shaft of the main propeller 100 and the cylindrical portion 419 is fixed to the housing of the motor 200, the approach of the main propeller 100 to the motor 200 also causes the rod to approach the recesses 421, 422 along the insertion direction 310 substantially parallel to the translation direction 320.

[0117] The separation of the guide elements 410 , 410 ′ from the recesses 421 , 422 may cause the first assembly 210 and the second assembly 220 to translate toward the working position to leave the rest position.

[0118] At least one of the rods may include a circumferential surface at its free end 412 that corresponds to a surface in contact with the recesses 421, 422. As seen in the locking system 400 shown in FIG4A, when the motor 200 applies a torque to the first component 210 and the second component 220 that is greater than a torque threshold of the locking system 400, the cooperation between these surfaces may cause the guide elements 410, 410' to move away from the recesses 421, 422 along the translation direction 320. The torque threshold of the locking system 400 may be determined at least in part by the geometry of the corresponding surfaces of the rod and the notch (e.g., based on the same phenomena related to stiffness and / or depth described previously).

[0119] To limit wear on the rod and / or notch of the locking system, each rod may include a rolling element. Each of the corresponding surfaces of the recesses 421 , 422 may have a rounded surface as described above for the recess 420 shown in FIG. 3A .

[0120] The main propeller 100 comprises two blades 101, 102, and the locking system 400 comprises two recesses 421, 422 to ensure two locking positions. When the main propeller 100 comprises more than two blades, another number of locking positions is provided. Another number of blades 101, 102 is also provided, as well as another number of recesses 421, 422 or guide elements 410, 410' which may be equal to or not equal to the number of blades 101, 102. For example, when the main propeller 100 comprises four blades 101, 102, 103, 104, the locking system 400 may comprise the two guide elements 410, 410' and the four recesses 421, 422, 423 and 424 shown in FIG.

[0121] A locking system 400 having several guide elements 410 , 410 ′ may have a higher torque threshold than a locking system 400 having a single guide element 410 .

[0122] As can be seen in FIGS. 4B and 4C , the locking system 400 shown in FIG. 5 can be reoriented relative to the translation direction 320 to suit the propulsion configuration between the main propeller 100 and the motor 200 .

[0123] According to one embodiment, an aircraft according to the present disclosure may be configured to lock and / or unlock the main propeller 100 during a flight, the flight comprising a first flight phase in which the air flow around the aircraft is substantially parallel to the axis of rotation of the main propeller and a second flight phase in which the air flow around the aircraft is substantially perpendicular to the axis of rotation 300 of the main propeller 100. For example, it may be configured to cruise laterally and take off and / or land vertically.

[0124] According to one embodiment, the aircraft can perform a flight maneuver including a step in which the thrust of the main propeller 100 is reduced until the first assembly 210 and the second assembly 220 are switched to the idle position. For example, the switching of the locking system 400 to the engaged configuration can be achieved when the main propeller 100 is stopped from being driven by the motor 200.

[0125] This step may allow the locking system 400 to switch from the free configuration to the engaged configuration. Alternatively or additionally, the flight maneuver may include a step in which the rotation of the main propeller 100 is released by applying a motor torque greater than a torque threshold of the locking system 400 to the first assembly 210 and the second assembly 220 of the motor 200. This step may allow the locking system 400 to switch from the engaged configuration to the free configuration.

[0126] For example, the aircraft can perform such a maneuver as part of a reorientation of the axis of rotation of the main propeller 100 relative to the fuselage of the aircraft. In this case, the locking of the main propeller 100 also allows avoiding gyroscopic effects caused by the rotation of the main propeller 100 around its axis of rotation during its reorientation.

[0127] The locking of the main propeller 100 can be used in many situations. For example, when stopping the motor drive achieved in the case of a flight phase (as described above), and / or during a motor 200 failure.

[0128] The ability to selectively lock or release the main propeller 100 without an engine allows avoiding operational safety problems and, moreover, allows reducing the energy consumption of the aircraft, compared to locking by electric motor torque or locking and selective release by electromagnets.

[0129] In general, if the separation of the main propeller 100 from the motor 200 has the effect of moving the recess 420 away from the guide element 410, then the locking system 400 can be considered to be usable with the motor 200 and main propeller 100 mated in the traction configuration. Likewise, if the proximity of the main propeller 100 to the motor 200 has the effect of moving the recess 420 away from the guide element 410, then the locking system 400 can be considered to be usable with the motor 200 and main propeller 100 mated in the propulsion configuration.

[0130] In order to manufacture a locking system 400 that can be used with a traction structure and with a propulsion structure (or vice versa) without changing its relative positioning with respect to the motor and with respect to the propeller, the orientation of the locking system 400 can be reversed in the translation direction 320 and the position of the recess 420 and the insertion element is reversed, so that the working position becomes the idle position.

[0131] 4B-4C and 2B and 2D, this can be accomplished by reversing the orientation of the locking system 400 and the position of the locking system 400 and motor 200 relative to the main propeller 100. This technique allows for the manner in which the recess 420 and guide element 410 are attached to the first and second assemblies 210, 220.

[0132] 4B and 5, the same effect can be obtained by reversing the orientation of the locking system 400 and the attachment of the guide element 410 and the recess 420 to the first and second components 210 and 220. This technique allows the position of the locking system 400 and the motor 200 to be maintained relative to the main propeller 100.

[0133] To apply this technique to the locking system 400 shown in FIG. 5 , it may be necessary to reverse the orientation of the cylindrical member 419 to maintain accessibility of the guide element 410 (whether in the form of one or several rods or one or several lugs) to the slots 421 , 422 , 423 , 424 .

[0134] To apply this technique to the locking system 400 shown in FIGS. 4A-4B (or the locking system shown in FIG. 4C ), it may also be necessary to reverse the orientation of the guide element 410 to maintain the ability of the lug to enter the notch 420 .

[0135] In order to apply this technique to the locking system 400 shown in Figures 2A-2B (or the locking system shown in Figures 2C-2D), it may be necessary to reverse the orientation of the cylindrical member 419 to maintain accessibility of the guide element 410 from the working position to the groove (if present) and / or to prevent the circumferential flange 418 (if present) from preventing switching from the working position to the idle position.

Claims

1. An aircraft, comprising a main propeller (100) driven in rotation by an electric motor (200), the electric motor having a first component (210) and a second component (220) which are rotationally movable relative to each other along a rotation axis (300), the main propeller being rotationally fixed to one of the first component and the second component, the aircraft comprising a locking system (400), the locking system comprising a recess (420, 421, 422) and a guide element (410, 410′), the recess being formed in one of the first component and the second component, the guide element being fixed to the other of the first component and the second component, the locking system having an engaged configuration and a free configuration, in the engaged configuration the guide element is at least partially inserted into the recess, in the free configuration the guide element is not at least partially inserted into the recess, the locking system being configured so that in the engaged configuration the rotational movement of the first component relative to the second component is limited to a predetermined angular sector, the locking system being configured to switch from the engaged configuration to the free configuration when the electric motor applies a rotational torque greater than a torque threshold on the first component or on the second component, characterized in that The first and second components are translationally movable relative to each other along a translation direction defined by the rotation axis between a rest position and an operating position, and the locking system can be in the engaged configuration only when the first and second components are in the rest position.

2. The aircraft according to claim 1, wherein: The guide element comprises a rolling element (411) which can be introduced into the recess.

3. An aircraft according to claim 1 or 2, the aircraft being configured so that the thrust generated during driving of the main propeller by the electric motor resists switching of the first and second assemblies from the operating position to the idle position.

4. The aircraft according to claim 1, wherein: The locking system comprises return means (413) tending to insert the guide element into the recess when the first and second assemblies are in the rest position.

5. The aircraft according to claim 4, wherein: The return device comprises a support spring (414) for pushing one of the guide element and the recess toward the other and a calibration screw (415) cooperating with the support spring to change the stiffness of the return device.

6. An aircraft according to claim 4 or 5, wherein: The guide element is inserted into the recess along an insertion direction (310) substantially perpendicular to the rotation axis, and the return means tends to insert the guide element into the recess when the first and second assemblies are in an idle position.

7. The aircraft according to claim 1, wherein: The guide element is inserted into the recess along an insertion direction (310) substantially parallel to the rotation axis, and when the locking system leaves the engaged configuration, the first component and the second component leave the rest position.

8. The aircraft according to claim 1, wherein: The locking system comprises several recesses.

9. The aircraft according to claim 8, wherein: The locking system comprises a number of recesses equal to the number of blades (101, 102) of the main propeller.

10. Aircraft according to claim 8 or 9, wherein the locking system comprises a smaller number of guide elements than the number of blades (101, 102) of the main propeller.

11. The aircraft according to claim 1, wherein: The predetermined angular sector is smaller than 5°.

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