Omni-directional propulsion vehicle with minimal overall dimensions

Abstract

The present invention relates to a propulsion vehicle comprising a chassis, a first shaft with a crown that is rotationally symmetrical about a first axis and rotatably mounted on the chassis about the first axis of rotation, a first drive system connected to the first shaft and capable of rotating the first shaft about the first axis, the first drive system including a second shaft rotatably mounted on the first shaft about a second axis of rotation that is orthogonal to the first axis of rotation, the second shaft being supported at two distinct points on the first shaft, the points defining a second axis of rotation, the second shaft supporting at least one propulsion unit of the vehicle, and a second drive system connected to the second shaft and capable of rotating the second shaft about the second axis of rotation.

Description

[Technical field]

[0001] The present invention relates to the field of propulsion vehicles, in particular to the field of remotely piloted aerial vehicles or drones, more particularly to a drone that is able to control the direction of the thrust generated by the propulsion units in any spatial direction and at the same time minimize the footprint of the drone, in particular the steering control system.

[0002] Remotely piloted aerial vehicles, also known as drones (unmanned aerial vehicles) or drones, comprise, in a known manner, a number of propulsion units, for example equipped with propellers or blades, mounted on a chassis. To control the direction of the drone, each propulsion unit may be equipped with an electric variable speed drive that can be remotely controlled, for example from a controller operated by a user. The direction of the drone can thus be controlled by increasing the rotational speed of the propellers of some propulsion units and / or decreasing the rotational speed of the propellers of other propulsion units.

[0003] This type of drone technology allows for control of the drone's direction, but does not provide sufficient drone piloting, especially over a wide range of speeds and / or movements. To overcome this drawback, it is also known to arrange each propulsion unit on a shaft that is pivotally mounted on a chassis, the shaft being capable of being driven by a motor. Thus, a user can remotely control the motor of the shaft in order to correct the orientation of the propulsion unit and thereby control the drone's direction.

[0004] Such a drone is described, for example, in US Patent Application Publication No. 2018354607. This document discloses an omnidirectional drone with a propulsion unit mounted on a system of two mutually concentric and rotationally symmetric shafts rotatably mounted on a chassis. The drone is characterized in that the axis of rotation of the first shaft is orthogonal to the axis of rotation of the second shaft. Thus, when a propulsion steering command is given, the shafts pivot about their respective axes of rotation to orient the propulsion unit according to the steering command.

[0005] In this type of architecture, the pivoting shafts on the chassis are oriented to follow the steering commands to the propulsion units, thereby increasing the overall size of the drone when the propulsion units are oriented in a particular direction. This raises the problem of how to reduce the overall size of the drone without limiting its maneuverability in all directions in space.

[0006] These drawbacks are also found in the field of underwater drones, also known as AUVs (autonomous underwater vehicles), and more broadly in any vehicle equipped with a rotary propulsion unit that must be supplied with electricity.

[0007] Therefore, a need exists for an omni-propulsion vehicle that is easier to maneuver and has a smaller overall size than known omni-propulsion vehicles.

[0008] The present invention is raised in this context and aims to fulfil this need.

[0009] To these ends, one subject of the invention is a propulsion vehicle, comprising: a. a chassis; b. a first shaft having a crown that is rotationally symmetric about a first axis and rotatably mounted on the chassis for rotation about the first axis of rotation; c. a first drive system connected to the first shaft and operable to rotate the first shaft about a first axis of rotation; d. The propelling vehicle is e. a second shaft rotatably mounted on the first shaft for rotation about a second axis of rotation perpendicular to the first axis of rotation, the second shaft being supported at two distinct points on the first shaft, the points defining a second axis of rotation, the second shaft supporting at least one propulsion unit of the propulsion vehicle; and f. A second drive system connected to the second shaft and capable of rotating the second shaft about a second axis of rotation.

[0010] It is therefore understood that the invention proposes the use of a system of shafts that mechanically cooperate with each other so that the propulsion unit of the propulsion vehicle can be oriented in any spatial direction. In addition, the structure of the system of shafts is arranged to minimize the overall dimensions of the propulsion vehicle during the operation to orient the propulsion unit by restricting the movement of both shafts to the same plane. In particular, when the first shaft rotates, the second shaft remains contained within the plane of rotation of the first shaft. Furthermore, when the second shaft rotates about the second axis, the thrust force of the propulsion unit can be oriented in any direction through the center and perpendicular to the second axis. Thus, by combining the rotation of the two shafts, the propulsion unit can be oriented in any desired spatial direction without significantly increasing the overall dimensions of the propulsion vehicle.

[0011] In the present invention, the chassis can take the form of a plate in which a space, for example a substantially circular space, is created in which the first shaft can rotate about a first axis of rotation. The chassis can be a stack of layers, for example including two central layers produced, for example, by 3D printing a polymer, in particular polylactic acid (PLA), or an underlayer of another material, for example carbon or aluminum.

[0012] Advantageously, the propulsion vehicle may comprise a power source capable of meeting the power consumption needs of the propulsion unit of the propulsion vehicle. For example, the power source may be a battery housed in a receptacle in the chassis provided for this purpose. Where applicable, one or more electrical cables may be housed in cavities provided between the central layers or in inserts provided in the central layers for routing the cables.

[0013] If desired, the chassis may comprise a plurality of spaces, in particular four spaces, and a plurality, in particular four, of first shafts, each supporting a propulsion unit and each driven by a first drive system, each rotatably mounted on the chassis in one of these spaces. Advantageously, each first shaft located in one of the spaces may comprise a second rotatably mounted shaft supporting a propulsion unit, each driven by a second drive system.

[0014] Preferably, the second drive may be housed within the first shaft at one of the points at which the second shaft is supported on the first shaft.

[0015] In one embodiment of the invention, the crown comprises a number of teeth arranged around at least a portion, in particular the entire circumference, of its circumference, and the first drive system comprises a pinion, or a gear, or a toothed wheel, driven by the motor and meshing with the teeth of the crown. According to this feature, the rotation of the shaft of the motor is transmitted to the crown via the pinion, gear or toothed wheel and the number of teeth, thereby simultaneously directing the thrust direction of the second shaft, the second axis and the propulsion unit.

[0016] Alternatively or additionally, in another embodiment of the invention, the first drive system comprises a belt driven by the motor and tensioned around the circumference of the crown, according to this feature, rotation of a shaft of the motor, fitted with a pulley tensioned by the belt, is transmitted via the belt to the crown, thereby simultaneously directing the thrust direction of the second shaft, the second axis and the propulsion unit.

[0017] Where applicable, the elements of the first drive system that mesh with the teeth and the teeth can be electrically conductive and electrically connected to one another, the elements being electrically connected to a power source and the teeth being electrically connected to a propulsion unit. Alternatively, at least the belt, the pulley and the portion of the crown through which the belt is tensioned can be electrically conductive, the pulley and the portion of the crown being electrically connected to one another through the belt, the pulley being electrically connected to a power source and the portion of the crown being electrically connected to a propulsion unit.

[0018] Advantageously, the propulsion vehicle comprises a first rotary guide member for guiding the first shaft in rotation about the first axis of rotation, the rotary guide member being arranged in mechanical cooperation with the first shaft in order to remove at least one degree of freedom from the first shaft. This feature makes it possible both to prevent any misalignment of the first shaft, in particular due to the mechanical stresses to which the structure of the propulsion vehicle is subjected throughout the flight path, and for the rotary guide member to reduce the overall dimensions of the propulsion vehicle by limiting the movements of the propulsion system.

[0019] Preferably, the first shaft comprises a first complementary member arranged to mechanically cooperate with the first rotation guide member in order to remove at least one degree of freedom from the first shaft. In other words, these members prevent the first shaft from moving in a given direction and / or from rotating about a given axis, which is necessarily separate from the first axis of rotation. The first rotation guide member and the first complementary member can cooperate to oppose movements of the first shaft parallel to the first axis of rotation and / or perpendicular to the first axis of rotation. It is possible to envisage that the first rotation guide member cooperates with the first complementary member to remove multiple degrees of freedom from the first shaft. Alternatively or additionally, it is possible to envisage that the chassis comprises a plurality of first rotational guide members, each cooperating with a first complementary member provided on the first shaft to remove a degree of freedom from the first shaft, it being understood that all of these first guide members and first complementary members may be structurally distinct from one another and / or may remove different degrees of freedom relative to one another and / or are involved in the function of transmitting power from the chassis to the first shaft.

[0020] Advantageously, the first rotating guide member and the first complementary member are electrically conductive and electrically connected to each other, the first rotating guide member being electrically connected to a power source and the first complementary member being electrically connected to the propulsion unit. It is therefore seen that the invention makes use of an element already present in the architecture of the propulsion vehicle, namely a member for guiding the first shaft as it rotates on the chassis, by giving it a second function of transmitting power. In particular, the rotating guide members present in the propulsion vehicle as well as the complementary members can be made of an electrically conductive material, in particular copper. These guide members can be direct contact guide members, guide members using friction rings or surface coatings, or guide members using rolling elements such as roller bearings, other types of bearings, or pads. Moreover, these rotating guide members necessarily come into contact with the complementary members along the first shaft to be able to perform their guiding function. By electrically connecting the rotating guide member to the power source of the propulsion vehicle and the complementary member to the propulsion unit of the propulsion vehicle, power can be transferred from the chassis to the propulsion unit via contact between the rotating guide member and the complementary member without it taking up additional space, even if the orientation of the propulsion unit changes as a result of shaft rotation.

[0021] In the present invention, the first rotating guide member can be electrically connected directly or indirectly to a power source, and the first complementary member can be directly or indirectly connected to a propulsion unit. The term "indirectly electrically connected" can indicate, for example, that one or more elements can be electrically positioned between the power source or the propulsion unit and the first rotating guide member or the first complementary rotating guide member, respectively. For example, a cable can be connected to a battery of the propulsion vehicle and soldered to the first rotating guide member.

[0022] Advantageously, the propulsion vehicle comprises a second rotating guide member for guiding the first shaft in rotation about the first axis of rotation, the first shaft comprising a second complementary member arranged in mechanical cooperation with the second rotating guide member to remove at least one degree of freedom from the first shaft, the second rotating guide member and the second complementary member being electrically conductive and electrically connected to each other, the second rotating guide member being electrically connected to a power source and the second complementary member being electrically connected to the propulsion unit. According to this feature, it is possible to transmit an electric current delivered by the power source, in particular an alternating or direct current, to the propulsion unit, the first rotating guide member-first complementary member pair forming, for example, a phase terminal or a positive terminal and the second rotating guide member-second complementary member pair forming, for example, a neutral or negative terminal.

[0023] Advantageously, it is possible, for example, to envisage that the second complementary member comprises a band mounted on the crown on a surface opposite to the surface on which the first complementary member is mounted, and that the second rotary guide member comprises pads that flatly support the band of the second complementary member. If applicable, the pads of the first and second rotary guide members can face each other. Preferably, the bands can be assembled on both sides of the crown by means of the same screw, which is fitted with an insulating member around its periphery. This insulating member prevents the current from passing directly from one band to the other. Alternatively, it is possible for the second complementary member to comprise a band mounted on the crown on the same surface that supports the first complementary member, such that the second complementary member is arranged concentrically with respect to the first complementary member, i.e. radially offset inwards or outwards with respect to the first complementary member. Where applicable, the second rotating guide member may include a pad to bear flat against the band of the second complementary member.

[0024] According to an additional or alternative embodiment of the present invention, one of the crown and the rotary guide member comprises a male element, and the other of the crown and the rotary guide member comprises a female element. According to this feature, the crown and the rotary guide member are coupled to ensure that the crown is guided during rotation. Thus, when the crown comprises a male element, this male element is accommodated within the female element of the rotary guide member. Conversely, when the crown comprises a female element, this female element accommodates the male element of the rotary guide member.

[0025] According to a further embodiment of the invention, the male element is a rib formed around at least a portion of the circumference of the crown, and the rotation guide member comprises a part rotatably mounted for rotation about an axis substantially parallel to the first axis, the part being provided with a groove forming the female element. According to this feature, the rib is received in the groove, which by its shape holds the rib in place when the crown rotates about the first axis.

[0026] Advantageously, the rib can have a profile that is substantially complementary to the profile of the groove of the part. For example, the rib and the groove can each have a trapezoidal profile, with the inclined surface of the rib abutting the inclined surface of the groove of the part. According to this feature, the trapezoidal profile helps to reduce friction between the rib and the rotating guide member, save energy and reduce stress on the material, thereby extending the service life of the propulsion vehicle. Alternatively, the crown comprises at least one groove around at least a part, in particular the entire circumference, of its circumference, the groove forming a female element as well as a first complementary member, the first rotating guide member comprising a part provided with a rib forming a male element, the first rotating guide member being rotatably mounted on the chassis to rotate about an axis that is substantially parallel to the first axis.

[0027] According to one example, the rib can be a central rib positioned at a central portion of the outer surface of the crown. If applicable, the crown can include a first plurality of teeth positioned above the central rib and a second plurality of teeth positioned below the central rib. In another embodiment, the rib can be an off-axis rib positioned at an upper edge or a lower edge of the outer surface of the crown. If applicable, the crown can include two off-axis ribs positioned at the upper and lower edges of the outer surface of the crown, respectively, the crown includes a plurality of teeth positioned between the two ribs, each rib fitting into a dedicated groove of the first rotating guide member.

[0028] Advantageously, the rotating guide member may comprise two rollers, in particular tapered rollers, arranged one above the other and arranged to define a space between the rollers forming a groove. Alternatively, the rotating guide member may comprise a bearing such as a grooved pulley.

[0029] In one alternative or additional embodiment of the invention, the crown comprises at least one rib around at least a portion, in particular the entire circumference, of its circumference, the rib forming a male element, and the first rotating guide member comprises a friction pad fixedly mounted on the chassis and provided with a groove forming a female element.

[0030] In one embodiment of the invention, the rotational guide member comprises an element for flatly supporting the lower and / or upper surface of the crown. According to this feature, the flat bearing element holds and guides the crown as it rotates.

[0031] Advantageously, the first complementary member comprises a band mounted on the crown and the first rotating guide member comprises a pad for supporting the band flat.

[0032] In one embodiment of the invention, the band is a section of a ring or a complete ring made of conductive material, in particular aluminum, which is fixed, for example by screwing, to the upper or lower surface of the crown of the first shaft. If applicable, it is possible to envisage a first complementary member with a plurality of bands distributed around the circumference of the crown of the first shaft. If desired, the band can be coated with a coating, in particular a film of conductive grease or oil, which is coated or impregnated on one or both of the strip and / or pad and positioned between the strip and the pad, in particular the coating can be incorporated into the pad during its manufacture. Preferably, at least one cable electrically connected to a power source can be soldered to the pad. Alternatively, the cable can be inserted into a lug attached to and electrically connected to the band.

[0033] Advantageously, the pads are made of a conductive material, in particular copper. The first rotating guide member may comprise a plurality of radially and / or longitudinally offset pads for supporting the band flat. Preferably, at least one cable electrically connected to a power supply may be soldered to the pads.

[0034] Advantageously, the first rotating guide member may also comprise a roller or roller bearing, in particular radially offset to the back surface of the pad or longitudinally offset from the pad, in contact with the crown of the first shaft or with the band. For example, the roller may be mounted on the chassis to rotate about an axis substantially parallel to the first axis of rotation and may be in contact with a rib provided on the crown. Alternatively, the roller bearing may be rotatably mounted on the chassis to rotate about an axis substantially perpendicular to the first axis of rotation, in particular passing through the center of the crown of the first shaft, and may be in contact with the upper or lower surface of the band.

[0035] If desired, the chassis, in particular the first rotating guide member, comprises a module for pressing the pad against the band. The pressing module is arranged to exert a force on the pad in the direction of the band. According to one example, the pad comprises a rod, at the end of which a plate is formed, and the pressing module can comprise a guide part into which the rod of the pad fits and a compression spring arranged around the rod and abutting on the one hand against the rim of the guide part and on the other hand against the plate of the pad. Alternatively, the pressing module can comprise a cavity opening towards the band and in which the pad is accommodated, and at least one compression spring fixed to the pad and to the bottom of the cavity.

[0036] Advantageously, the rotating guide member is attached to the chassis by threading into an oval hole, this feature allowing the position of the rotating guide member to be adjusted over a continuous range of positions.

[0037] It is possible to envisage a chassis comprising a number of first rotating guide members, each cooperating with a complementary first member provided on a first shaft, for example one first rotating guide member comprising a number of pads for supporting flat the band mounted on the crown and two tapered rollers arranged one above the other and between which the peripheral rib of the crown is housed, and two other first guide members each comprising only two tapered rollers arranged one above the other and between which the peripheral rib of the crown is housed. If applicable, it is possible for only a part and / or only one or a part of one of these pairs of first rotating guide members-first complementary members to be electrically conductive and / or to be electrically connected to a power supply and to the propulsion unit.

[0038] In one embodiment of the invention, the propulsion vehicle comprises a plurality of fixed legs extending from a chassis to a common base to which the plurality of fixed legs are attached, and a plurality of movable legs extending from a movable base rotatably mounted on the common base for rotation about a first axis of rotation to a crown to which the plurality of movable legs are attached. This feature allows the first shaft to be kept suspended and allows thrust from the propulsion unit to be transmitted to the entire propulsion vehicle as the propulsion unit moves.

[0039] Advantageously, the propulsion vehicle comprises a central control unit for the propulsion vehicle, capable of data exchange with the propulsion unit. At least one cable extends from the central control unit to the rotating collector via one of the fixed legs and another cable extends from the rotating collector to the propulsion unit via one of the movable legs. This embodiment is particularly advantageous when the first shaft is a crown, since this set of legs makes it possible to ensure that the first shaft is held in place on the chassis and is therefore provided on the chassis and suspended in a space in which it can rotate. This tubular support structure can therefore be used to route through it a cable for data exchange between the central control unit and the propulsion unit. The common base and the movable base form a common hollow in which the rotating collector is arranged. This type of rotating collector, which makes it possible to electrically connect the fixed part of the common base to the rotating part of the movable base, is known per se and will not be described in more detail.

[0040] Preferably, the central control unit of the propulsion vehicle is capable of exchanging data with one or more sensors of the propulsion unit, such as an inertial measurement unit, and / or with variable speed drives of one or more motors of the propulsion unit.

[0041] Advantageously, the fixed legs are attached to the chassis and distributed around the entire periphery of the chassis volume about which the first shaft can rotate about the first axis of rotation.Once again, advantageously, the movable legs are attached to the crown of the first shaft and distributed around the entire periphery of this crown.Preferably, the fixed legs and the movable legs are arranged such that the common base and the movable base overhang the crown and are positioned on the first axis of rotation.

[0042] Advantageously, the second drive device comprises a motor provided with a rotating shaft rotating about a second axis of rotation, the second shaft comprising a transmission member mechanically connected to the rotating shaft of the motor, whereby rotation of the shaft of the motor is transmitted to the second shaft, a first complementary member of the second shaft comprising a first bearing mounted on the transmission member of the second shaft, and a first rotation guide member of the first shaft comprising a second bearing mounted concentrically around the first bearing.

[0043] Advantageously, the first bearing and the second bearing are electrically conductive and electrically connected to each other. This configuration significantly reduces the size and weight of the components involved in the transfer of power to the propulsion unit.

[0044] Advantageously, the first bearing may be a ring or sleeve made of an electrically conductive material, in particular copper, for example sintered copper impregnated with a lubricant such as an electrically conductive or non-conductive grease, whose longitudinal axis is substantially identical to the axis of rotation of the second bearing and which is mounted in a fixed manner on a transmission member of the first shaft fitted in this second bearing. If applicable, at least one cable electrically connected directly or indirectly to the propulsion unit may be soldered to the first bearing. Alternatively, the cable may be inserted into a lug mounted on and electrically connected to the first bearing.

[0045] Preferably, the second bearing may be a ring or sleeve made of a conductive material, in particular copper, whose longitudinal axis is substantially identical to the second rotation axis, freely or fixedly mounted on the first shaft and whose diameter is substantially larger than that of the first bearing. If applicable, at least one cable electrically connected to a power source may be soldered to the second bearing. Alternatively, the cable may be inserted into a lug attached to and electrically connected to the first bearing.

[0046] Advantageously, the inner surface of the second bearing and the outer surface of the first bearing are smooth and in direct contact with each other. Alternatively, a coating, in particular a conductive grease or oil coating that coats or impregnates one or both of the bearings, can be positioned between the inner surface of the second bearing and the outer surface of the first bearing, in particular the coating can be incorporated into the pads during their manufacture.

[0047] Advantageously, the propulsion vehicle comprises a central control unit for the propulsion vehicle capable of data exchange with the propulsion unit, the second shaft comprises two diametrically opposed pivots each pivotally mounted in a recess of the first shaft, the recesses facing each other, a transmission member of the second shaft is arranged on one of the pivots of the second shaft so as to extend into one of the recesses, a rotating shaft of the motor extends into this recess, a rotating collector is arranged in the other of the recesses of the first shaft, at least one cable extends from the central control unit to the rotating collector through the first shaft and another cable extends from the rotating collector to the propulsion unit through the second shaft. Preferably, the rotating collector can be connected to the central control unit of the propulsion vehicle, for example via a rotating collector provided on the common base and on the mobile base.

[0048] According to one example, the crown of the first shaft comprises two tabs oriented radially towards the inside of the crown, the tabs being diametrically opposed and each tab receiving one of the points at which the second shaft is supported on the first shaft. Advantageously, each tab is arranged to define, by its structure, a recess suitable for receiving a mechanical structure. In particular, the mechanical structure can be attached to the recess defined by the tabs by means of screws, adhesive or other attachment means. Preferably, the second drive system can be mounted on one of the tabs. If applicable, the rotating collector can be mounted on the other of the tabs. Advantageously, two protective half shells can be adapted to be attached on either side of each tab to define the recess of the first shaft.

[0049] In one embodiment of the invention, the second drive system comprises a transmission cylinder of polygonal cross section driven by the motor and inserted into an opening of the second shaft, the cross section of the opening being complementary to the cross section of the transmission cylinder, the connection between the transmission cylinder and the opening of the second shaft forming one of the points at which the second shaft is supported on the first shaft. According to this feature, the rotation of the shaft of the motor is transmitted to the second shaft, in addition, the polygonal cross section of the cylinder increases the efficiency of transmission of the motor torque by increasing the contact area between the transmission cylinder and the connection.

[0050] Alternatively or additionally, in another embodiment of the invention, the second drive system comprises a drive belt driven by the motor, the belt being tensioned on a pulley mounted on the second shaft, according to this feature, rotation of the shaft of the motor, on which the pulley on which the belt is tensioned, is transmitted to the second shaft, thereby simultaneously directing the propulsion unit and the thrust direction of the propulsion unit.

[0051] Advantageously, the second shaft comprises two diametrically opposed pivots, each pivotally mounted in a recess of the first shaft, the recesses facing each other. Where applicable, the second bearing comprises a peripheral stop, in particular extending around the entire circumference of the second bearing and preferably formed by the edge of the second bearing, the recess comprising a peripheral groove in which the peripheral stop of the second bearing is received. This peripheral stop and this peripheral groove make it possible to prevent translation of the second shaft in a direction perpendicular to and in the same plane as the second axis of rotation.

[0052] Preferably, the first bearing comprises a peripheral stop, in particular extending around the entire periphery of the first bearing and preferably formed on the edge of the first bearing. If applicable, the peripheral stop of the first bearing may face the peripheral rim of the recess and / or be clamped between the peripheral stop of the second bearing and a rim of the second shaft provided in line with the transmission member of the second shaft. These features make it possible to reinforce the blocking of the translation of the second shaft in a direction perpendicular to the second axis of rotation and in any direction in the same plane as the second axis of rotation. Alternatively, the peripheral stop of the second bearing may be positioned opposite the second bearing and the peripheral stop to abut against the wall of the second shaft opposite the wall of the recess, so as to abut against the wall of the recess and the peripheral stop of the first bearing. In other words, the bearings are clamped between the opposing walls of the recess and the second shaft via their stops.

[0053] In a further embodiment of the present invention, the motor comprises a rotating shaft inserted into the transmission cylinder, and a set screw is screwed into a tapped hole in the transmission cylinder to fix the transmission cylinder to the rotating shaft of the motor. This feature allows the rotation of the motor shaft to be suitably transmitted to the transmission cylinder, and the set screw ensures friction between the cylinder and the motor shaft.

[0054] Alternatively, the transmission cylinder may be of circular cross section and truncated to form a flat surface. If applicable, the motor may comprise a rotating shaft rotating about a first axis of rotation and inserted into the transmission cylinder, with a set screw provided collinear with the cavity of the transmission cylinder into which the motor's rotating shaft is inserted being screwed into a tapped hole in the transmission cylinder to fix the transmission cylinder to the motor's rotating shaft. Alternatively, it is possible to envisage a transmission member comprising a portion of a polygonal cross section inserted into an opening of complementary cross section made in the transmission cylinder.

[0055] In one embodiment of the invention, the second shaft comprises a central portion supporting a propulsion unit and two rods extending on either side from the central portion along the second axis of rotation to a point where the second shaft is supported on the first shaft. According to this feature, the propulsion unit is connected to the chassis of the propulsion vehicle and can then transmit thrust to move the propulsion vehicle.

[0056] Preferably, the propulsion unit comprises a propeller driven by a motor rotating about a third axis of rotation perpendicular to the second axis of rotation, This feature makes it possible to direct the thrust of the propulsion unit in any spatial direction through the center of the propulsion unit.

[0057] Advantageously, the second shaft supports two propulsion units mounted on either side of the second shaft, each fitted with a propeller, the propellers of the propulsion units being contra-rotating propellers, a feature which allows a greater thrust to be obtained whilst eliminating torques which cause gyroscopic effects.

[0058] In one embodiment of the invention, the propulsion vehicle is an omnidirectional aerial drone.

[0059] The propulsion unit may be a blade or propeller-based propulsion unit, a reaction turbine, or more generally any type of propulsion unit that can be oriented by pivoting and requires a power supply source, in particular provided with a rotor and a stator. [Brief description of the drawings]

[0060] Other advantages and features of the present invention will now be explained by way of examples, which are merely illustrative and do not in any way limit the scope of the invention, and on the basis of the attached drawings, in which: [Figure 1] 1 shows a schematic and partial perspective view of an omnidirectional drone according to one embodiment of the present invention; [Diagram 2] FIG. 2 shows a schematic and partial top view of the omnidirectional drone of FIG. [Diagram 3] FIG. 2 shows a schematic and partial perspective view of a portion of the omnidirectional drone of FIG. [Figure 4] FIG. 2 shows a schematic and partial perspective view of a pair of rotating guide members and complementary members of the omnidirectional drone of FIG. [Diagram 5] FIG. 4 shows another perspective view of a portion of the omnidirectional drone of FIG. 3, partially and diagrammatically. [Figure 6A] FIG. 2 shows a schematic and partial cross-sectional view of one connection between two shafts of the omnidirectional drone of FIG. [Figure 6B] FIG. 2 shows a schematic and partial exploded view of another connection between two shafts of the omnidirectional drone of FIG. 1;

[0061] In the following description, unless otherwise specified, identical elements appearing in different figures depending on their structure or function retain the same reference numbers.

[0062] FIG. 1 shows a propulsion vehicle in the form of an omnidirectional drone D, comprising a chassis C in which four chambers are arranged, each chamber supporting a first shaft A1, rotationally symmetric about a first axis of rotation AX1 and including a crown K mounted to rotate about the first axis AX1. Each crown K supports a second shaft A2 mounted to rotate about a second axis AX2 perpendicular to the first axis AX1, mounted with a propeller P, in particular with counter-rotating propellers. The center of the chassis C supports a central control unit UCC, in particular capable of controlling the rotation speed of the propulsion unit P, and a battery SE, in particular arranged to power the propulsion system of the drone C. The chassis C also comprises a first drive system E1 for each first shaft A1 mounted on the chassis C.

[0063] FIG. 2 shows a top view of the omnidirectional drone D. FIG. 3 shows a perspective view of the first shaft A1-second shaft A2-propeller P assembly of the omnidirectional drone of FIG. 1. FIG. 4 shows a perspective view of a set of rotating guide members and one of the complementary members of the assembly of FIG. 3. FIG. 5 shows another perspective view of the first shaft A1-second shaft A2-propeller P assembly of FIG. 3. FIG. 6A shows a cross-sectional view of one connection between the first shaft A1 and the second shaft A2 of the assembly of FIG. 3. FIG. 6B shows an exploded view of another connection between the first shaft A1 and the second shaft A2 of the assembly of FIG. 3. In the following, only one of these assemblies will be described, but it will be understood that the four assemblies visible in FIG. 1 and FIG. 2 are identical.

[0064] The drone D comprises a number of fixed legs PPF extending from the chassis C to a common base supported by the chassis C to which the fixed legs are attached, and a number of mobile legs PPM extending from a mobile base rotatably mounted on the common base to rotate about a first axis of rotation AX1. The mobile legs PPM are attached to the first shaft A1 and distributed around its entire circumference. The first shaft A1 is thus suspended in a dedicated space while remaining rotatable about the first axis of rotation AX1.

[0065] As shown in FIG. 3, the crown K includes a first plurality of teeth RD1 disposed on an upper rim of the crown K around its entire circumference, and a second plurality of teeth RD2 disposed on a lower rim of the crown K around its entire circumference.

[0066] The first drive system E1 comprises a motor driving a pinion PGN, as can be seen in Fig. 4. This pinion PGN comprises two toothed regions parallel to each other and arranged around the entire portion of the upper rim of the pinion PGN circumference and around the entire portion of the lower rim of the pinion circumference. Each of these two toothed regions is arranged so that the rotation of the pinion PGN by the motor is transmitted to the crown K and thus to the shaft A1 by meshing with a number of upper and lower teeth RD1 and RD2 of the crown K. The shaft A1 therefore pivots around a rotation axis AX1 which is identical to the rotation axis of the crown K.

[0067] The crown K comprises a central rib N arranged around the entire central part of its circumference between a first plurality of teeth RD1 and a second plurality of teeth RD2. The chassis C comprises two first guide members OGR1_1, each of which takes the form of a grooved bearing whose profile is complementary to the geometric shape of the rib N. The rib N is received in a groove of each bearing OGR1_1 and thus forms a first complementary member OC1_1 which mechanically cooperates with the first guide member OGR1_1. In the example described, the rib N and the groove of each bearing OGR1_1 have a trapezoidal profile, the inclined surface of the rib N abutting the inclined surface of this groove.

[0068] As shown in Figure 3, the crown K of the first shaft A1 is surrounded by two parallel rings B1 and B2, which fit on the upper and lower faces of the crown K. These rings B1 and B2 are rotationally symmetric about the axis AX1 and are securely mounted on the crown K by attachment means MF at various points on the first shaft A1. In the example described, the attachment means take the form of screws that are screwed through each of the bands B1 and B2 and through the crown K.

[0069] As shown in Figure 4, the chassis C comprises another first rotating guide member OGR1_2 including a plurality of friction pads 3PF1 in the form of three successive pads which bear flat against the upper ring B1 and thus form another first complementary member OC1_2 cooperating with the other first rotating guide member OGR1_2.

[0070] Each friction pad 3PF1 comprises a rod and a plate provided at the end of a shaft to support flat the upper ring B1. The rod is mounted in a guide cylinder and a compression spring RC is arranged around the rod, one of which rests against the upper wall of the guide cylinder and the other against the plate of the pad. Each pad 3PF1 therefore exerts a force perpendicular to the surface of ring B1 towards ring B2.

[0071] Symmetrically, the chassis C comprises a second rotary guide member OGR2 including a number of friction pads 3PF2 arranged opposite the pads 3PF1, which pads 3PF2 bear flat against the lower ring B2 and thus cooperate with the second rotary guide member OGR2 to form a second complementary member OGR2.

[0072] In this way, the first shaft A1 is guided simultaneously during rotation by the first guide members OGR1_1 and OGR1_2 and by the second guide member OGR2.

[0073] One will notice the presence of a third grooved bearing OGR1_3 provided on the rear side of the friction pads 3PF1 and 3PF2 and cooperating with a rib N of the crown K.

[0074] As shown in Figure 3, the bands B1 and B2 are made of a conductive material, in this case aluminum, and likewise the friction pads 3PF1 and 3PF2 are made of a conductive material, in this case copper.

[0075] Each band B1 and B2 is therefore connected to the battery SE of the drone D through electrical contact with the friction pads 3PF1 and 3PF2. Each pad 3PF1 and 3PF2 is electrically connected to the battery SE by a cable, in particular soldered to a rod of this pad, which cable is for example routed through a cavity of the chassis C and / or between two inner layers of this chassis C. As will be explained later below, each band B1 and B2 is electrically connected to the propulsion unit P. One of the bands B1 can therefore act as a positive terminal or a phase terminal, depending on whether the power source SE delivers a direct or alternating current, and the other band B2 can therefore act as a negative or neutral terminal.

[0076] As shown in Figures 5 and 6B, the crown K of the first shaft A1 comprises two tabs L1 and L2 oriented radially towards the inside of the crown K, the tabs being diametrically opposed. Each tab L1 and L2 thus defines a recess for receiving one of the ends EXT1 and EXT2 of the second shaft A2, to which this end is thus pivotally connected. The tabs L1 and L2 thus define a second axis of rotation AX2. In the example described, each tab comprises an upper half shell and a lower half shell (seen in Figure 6A), which together define a cavity for receiving one end of the shaft A2.

[0077] As shown in Fig. 6A, at the tab L1 and at the first end EXT1 of the second shaft A2, the first shaft A1 supports a second drive system E2 capable of pivoting the second shaft A2 about a second axis of rotation AX2. The second drive system E2 comprises a transmission cylinder CT with a polygonal, in this case hexagonal, cross section, driven by the motor and inserted into an opening OR provided in the first end EXT1 of the second shaft A2, the cross section of which is complementary to that of the transmission cylinder CT. It will be noted that this first end EXT1 thus forms a member for transmitting the rotation of the motor of the second drive system E2 to the second shaft A2.

[0078] As shown in Figures 6A and 6B, the second shaft A2 is provided at each of its ends EXT1 and EXT2 with a first bearing PL1, in this case a sleeve bearing, in which this end is fixedly fitted. For each tab L1 and L2, the first shaft A2 is provided with a second bearing PL2, also in the form of a sleeve bearing, freely located in the recess defined by this tab. The second bearing PL2 is arranged concentrically around the first bearing PL1, the inner surface of the second bearing PL2 and the outer surface of the first bearing PL1 being smooth and in direct contact with each other. Thus, the second bearing PL2 of the tab L1 forms a first rotational guide member DOGR_1 of the second shaft A2 and therefore the first bearing PL1 of the end EXT1 forms a first complementary member DOC_1 which mechanically cooperates with the first member DOGR_1, while the second bearing PL2 of the tab L2 forms a second rotational guide member DOGR_2 of the second shaft A2 and therefore the first bearing PL1 of the end EXT2 forms a second complementary member DOC_2 which mechanically cooperates with the second member DOGR_2.

[0079] Each first bearing PL1 and each second bearing PL2 is made of an electrically conductive material, in particular copper. For each end EXT1 and EXT2, one cable (not shown) electrically connected to the propulsion unit P is soldered to the first bearing PL1, while the other cable electrically connected to the upper ring B1 or the lower ring B2 is soldered to the second bearing PL2. Thus, the power delivered by the battery SE can be transferred to the propulsion unit P via the pads 3PF1 and 3PG2, the rings B1 and B2, the first bearing PL1 and the second bearing PL2.

[0080] Each second bearing PL2 comprises a peripheral stop BT2 formed on its edge, and the recess of each tab L1 and L2 comprises a peripheral groove GP, visible in Figures 6A and 6B, in which the peripheral stop BT2 of the second bearing PL2 is received. The first bearing PL1 comprises a peripheral stop BT1 formed on its edge, which stop BT2 is clamped between the wall of the second shaft A2 and the edge of the second bearing PL2.

[0081] The second shaft A2 comprises a central part PCE, seen in FIG. 5, which supports the propulsion unit (P) as well as two rods extending on either side from the central part PCE along the second axis of rotation A2 to form ends EXT1 and EXT2.

[0082] Finally, one rotating collector (not shown) is arranged on the common base and on the movable base connecting the fixed leg PPF to the movable leg PPM, while another rotating collector COL is arranged in a recess in the tab L2 of the first shaft A1 which accommodates the second end EXT2 of the second shaft.

[0083] At least one cable (not shown) connects the central control unit UCC to this rotating collector through one of the fixed legs PPF, while another cable runs from this rotating collector to the other rotating collector COL through one of the movable legs PPM and inside the first shaft A1, for example inside a cavity in the crown K. Finally, a cable connects this rotating collector COL to the propulsion unit P through a cavity provided in the second shaft A2.

[0084] It will be appreciated that although the invention has been described in the context of an omnidirectional aerial drone, the invention may extend to other types of drones, such as underwater drones or AUVs, or to other types of propelled vehicles, which may or may not be remotely controllable, such as cars, motorcycles, trucks, bicycles, trains, planes, helicopters, ships, etc.

[0085] The above description clearly explains how the present invention achieves its set object, i.e., how to reduce the overall size of the propulsion system of an omni-directional propulsion vehicle by providing a system of shafts, a first shaft rotatably mounted on a chassis of the propulsion vehicle, the movement of the first shaft being limited by a rotational guide member, a second shaft supporting a propeller being rotatably mounted on the first shaft, and the shafts being arranged to be driven by first and second drive systems, respectively.

[0086] In any case, the invention is not limited to the embodiments specifically described in this document, but in particular extends to any equivalent means and to any technically valid combination of these means. In particular, it is possible to envisage other construction materials, in particular electrically conductive materials, and magnetic guide elements, in particular electromagnets. Similarly, any number of propulsion units can be rotatably mounted on the second shaft to modify the total thrust of the propulsion vehicle and therefore the maximum speed achievable by this propulsion vehicle.

Claims

1. A propulsion vehicle (D), a. Chassis (C) and, b. A first shaft (A1) is rotatably mounted on the chassis (C) so as to rotate about the first axis of rotation (AX1), and includes a crown (K) that is rotationally symmetric with respect to a first axis (AX1), c. A first drive system (E1) connected to the first shaft (A1) and capable of rotating the first shaft about the first rotation axis (AX1), The aforementioned propulsion vehicle, d. A second shaft (A2) rotatably mounted on the first shaft (A1) so as to rotate about a second axis of rotation perpendicular to the first axis of rotation, wherein the second shaft (A2) is supported at two separate points (X1) and (X2) on the first shaft (A1), the points defining the second axis of rotation, and the second shaft supports at least one propulsion unit (P) of the propulsion vehicle (D), e. A propulsion vehicle characterized by comprising a second drive system (E2) connected to the second shaft (A2) and capable of rotating the second shaft about the second rotation axis.

2. The propulsion vehicle according to claim 1, characterized in that the crown (K) comprises a plurality of teeth (RD1) arranged around at least a portion of its circumference, and the first drive system (E1) comprises a pinion (PGN) driven by a motor and meshing with the teeth (RD1) of the crown (K).

3. The propulsion vehicle according to claim 1 or 2, characterized in that the first drive system (E1) is driven by a motor and comprises a belt stretched around the circumference of the crown (K).

4. The propulsion vehicle according to claim 1, wherein the propulsion vehicle comprises a member (OGR) for guiding the first shaft (A1) when it rotates around the first axis (AX1), and the rotation guide member (OGR) is arranged to mechanically cooperate with the first shaft (A1) in order to remove at least one degree of freedom from the first shaft (A1).

5. The propulsion vehicle according to claim 4, characterized in that one of the crown (K) and the rotating guide member (OGR) is provided with a male element (M), and the other of the crown (K) and the guide member (OGR) is provided with a female element.

6. The propulsion vehicle according to claim 5, characterized in that the crown (K) has at least one rib (N) around at least a portion of its circumference, the rib forming the male element, and the rotating guide member (OGR) has a component mounted to rotate about an axis substantially parallel to the first rotation axis (AX1), the component being provided with a groove (G) forming the female element.

7. The propulsion vehicle according to claim 4, characterized in that the rotating guide member (OGR) includes an element that flatly supports the lower or upper surface of the crown (K).

8. The propulsion vehicle according to claim 4, characterized in that the rotating guide member (OGR) is attached to the chassis (C) by screwing it into an elliptical hole.

9. The propulsion vehicle according to claim 1, comprising: a plurality of fixed legs (PPF) extending from the chassis (C) to a common base (EC) to which the plurality of fixed legs (PPF) are attached; and a plurality of movable legs (PPM) extending from a movable base (EM) rotatably mounted on the common base (EC) so as to rotate about a first rotation axis (AX1) to the crown (K) to which the plurality of movable legs (PPM) are attached.

10. The propulsion vehicle according to claim 1, wherein the crown (K) comprises two tabs (L), (L1) and (L2), the tabs being radially oriented toward the inside of the crown, the tabs (L) facing each other in the radial direction, and each tab (L) accommodating one of the points on which the second shaft (A2) is supported on the first shaft (A1).

11. The propulsion vehicle according to claim 1, wherein the second drive system (E2) comprises a polygonal cross-section transmission cylinder (CT) driven by a motor (MT) and inserted into an opening (O) of the second shaft (A2), the cross-section of the opening being complementary to the cross-section of the transmission cylinder, and the connection between the transmission cylinder and the opening of the second shaft (A2) forming one of the points on which the second shaft is supported on the first shaft (A1).

12. The propulsion vehicle according to claim 1, characterized in that the motor comprises a rotating shaft (AR) inserted into the transmission cylinder (CT), and a set screw (VP) is screwed into a tapped hole in the transmission cylinder (CT) to fix the transmission cylinder (CT) to the rotating shaft of the motor.

13. The propulsion vehicle according to claim 1, characterized in that the second shaft (A2) has a central portion (PC) that supports the propulsion unit (P) and two rods (T1) and (T2), and the two rods extend on both sides along the second rotation axis (AX2) from the central portion (PC) to the point where the second shaft (A2) is supported on the first shaft (A1).

14. The propulsion vehicle according to claim 1, characterized in that the second shaft (A2) supports two propulsion units (P) mounted on both sides of the second shaft (A2), each propulsion unit (P) is provided with a propeller, and the propellers of the propulsion units are counter-rotating propellers.

15. The propulsion vehicle (D) according to claim 1, characterized in that the propulsion vehicle is an omnidirectional aerial drone.

Images